Vendor import of lldb trunk r307894:vendor/lldb/lldb-trunk-r307894

https://llvm.org/svn/llvm-project/lldb/trunk@307894

78 files changed, 1151 insertions, 1485 deletions

diff --git a/docs/lldb-gdb-remote.txt b/docs/lldb-gdb-remote.txt
index a4427a70444d..0000738b556b 100644
--- a/docs/lldb-gdb-remote.txt
+++ b/docs/lldb-gdb-remote.txt
@@ -126,6 +126,32 @@ read packet: $OK#00
 This packet can be sent one or more times _prior_ to sending a "A" packet.
 
 //----------------------------------------------------------------------
+// "QEnableErrorStrings"
+//
+// BRIEF
+//  This packet enables reporting of Error strings in remote packet
+//  replies from the server to client. If the server supports this
+//  feature, it should send an OK response. The client can expect the
+//  following error replies if this feature is enabled in the server ->
+//
+//  EXX;AAAAAAAAA
+//
+//  where AAAAAAAAA will be a hex encoded ASCII string.
+//  XX is hex encoded byte number.
+//
+//  It must be noted that even if the client has enabled reporting
+//  strings in error replies, it must not expect error strings to all
+//  error replies.
+// 
+// PRIORITY TO IMPLEMENT
+//  Low. Only needed if the remote target wants to provide strings that
+//  are human readable along with an error code.
+//----------------------------------------------------------------------
+
+send packet: $QErrorStringInPacketSupported
+read packet: $OK#00
+
+//----------------------------------------------------------------------
 // "QSetSTDIN:<ascii-hex-path>"
 // "QSetSTDOUT:<ascii-hex-path>"
 // "QSetSTDERR:<ascii-hex-path>"
@@ -250,11 +276,12 @@ read packet: OK
 //
 //  Each tracing instance is identified by a trace id which is returned
 //  as the reply to this packet. In case the tracing failed to begin an
-//  error code is returned instead.
+//  error code along with a hex encoded ASCII message is returned
+//  instead.
 //----------------------------------------------------------------------
 
 send packet: jTraceStart:{"type":<type>,"buffersize":<buffersize>}]
-read packet: <trace id>/E<error code>
+read packet: <trace id>/E<error code>;AAAAAAAAA
 
 //----------------------------------------------------------------------
 // jTraceStop:
@@ -283,12 +310,12 @@ read packet: <trace id>/E<error code>
 //                  to stop tracing on that thread.
 //  ==========      ====================================================
 //
-//  An OK response is sent in case of success else an error code is
-//  returned.
+//  An OK response is sent in case of success else an error code along
+//  with a hex encoded ASCII message is returned.
 //----------------------------------------------------------------------
 
 send packet: jTraceStop:{"traceid":<trace id>}]
-read packet: <OK response>/E<error code>
+read packet: <OK response>/E<error code>;AAAAAAAAA
 
 //----------------------------------------------------------------------
 // jTraceBufferRead:
@@ -317,11 +344,11 @@ read packet: <OK response>/E<error code>
 //  ==========      ====================================================
 //
 //  The trace data is sent as raw binary data if the read was successful
-//  else an error code is sent.
+//  else an error code along with a hex encoded ASCII message is sent.
 //----------------------------------------------------------------------
 
 send packet: jTraceBufferRead:{"traceid":<trace id>,"offset":<byteoffset>,"buffersize":<byte_count>}]
-read packet: <binary trace data>/E<error code>
+read packet: <binary trace data>/E<error code>;AAAAAAAAA
 
 //----------------------------------------------------------------------
 // jTraceMetaRead:
@@ -359,11 +386,11 @@ read packet: <binary trace data>/E<error code>
 //  gdb-remote protocol has certain limitations, binary escaping
 //  convention is used.
 //  In case the trace instance with the <trace id> was not found, an
-//  error code is returned.
+//  error code along with a hex encoded ASCII message is returned.
 //----------------------------------------------------------------------
 
 send packet: jTraceConfigRead:{"traceid":<trace id>}
-read packet: {"conf1":<conf1>,"conf2":<conf2>,"params":{"paramName":paramValue}]}];/E<error code>
+read packet: {"conf1":<conf1>,"conf2":<conf2>,"params":{"paramName":paramValue}]}];/E<error code>;AAAAAAAAA
 
 //----------------------------------------------------------------------
 // "qRegisterInfo<hex-reg-id>"
diff --git a/include/lldb/Host/Host.h b/include/lldb/Host/Host.h
index c41e4796f532..da0b8e14c4a7 100644
--- a/include/lldb/Host/Host.h
+++ b/include/lldb/Host/Host.h
@@ -7,14 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef liblldb_Host_h_
-#define liblldb_Host_h_
-#if defined(__cplusplus)
-
-#include <stdarg.h>
-
-#include <map>
-#include <string>
+#ifndef LLDB_HOST_HOST_H
+#define LLDB_HOST_HOST_H
 
 #include "lldb/Host/File.h"
 #include "lldb/Host/HostThread.h"
@@ -22,6 +16,11 @@
 #include "lldb/Utility/StringList.h"
 #include "lldb/lldb-private-forward.h"
 #include "lldb/lldb-private.h"
+#include <cerrno>
+#include <map>
+#include <stdarg.h>
+#include <string>
+#include <type_traits>
 
 namespace lldb_private {
 
@@ -254,5 +253,4 @@ template <> struct format_provider<lldb_private::WaitStatus> {
 };
 } // namespace llvm
 
-#endif // #if defined(__cplusplus)
-#endif // liblldb_Host_h_
+#endif // LLDB_HOST_HOST_H
diff --git a/include/lldb/Host/common/NativeProcessProtocol.h b/include/lldb/Host/common/NativeProcessProtocol.h
index a97540499cd3..5f2157510c0a 100644
--- a/include/lldb/Host/common/NativeProcessProtocol.h
+++ b/include/lldb/Host/common/NativeProcessProtocol.h
@@ -19,6 +19,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Error.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include <vector>
 
@@ -244,68 +245,57 @@ public:
   virtual Status GetFileLoadAddress(const llvm::StringRef &file_name,
                                     lldb::addr_t &load_addr) = 0;
 
-  //------------------------------------------------------------------
-  /// Launch a process for debugging. This method will create an concrete
-  /// instance of NativeProcessProtocol, based on the host platform.
-  /// (e.g. NativeProcessLinux on linux, etc.)
-  ///
-  /// @param[in] launch_info
-  ///     Information required to launch the process.
-  ///
-  /// @param[in] native_delegate
-  ///     The delegate that will receive messages regarding the
-  ///     inferior.  Must outlive the NativeProcessProtocol
-  ///     instance.
-  ///
-  /// @param[in] mainloop
-  ///     The mainloop instance with which the process can register
-  ///     callbacks. Must outlive the NativeProcessProtocol
-  ///     instance.
-  ///
-  /// @param[out] process_sp
-  ///     On successful return from the method, this parameter
-  ///     contains the shared pointer to the
-  ///     NativeProcessProtocol that can be used to manipulate
-  ///     the native process.
-  ///
-  /// @return
-  ///     An error object indicating if the operation succeeded,
-  ///     and if not, what error occurred.
-  //------------------------------------------------------------------
-  static Status Launch(ProcessLaunchInfo &launch_info,
-                       NativeDelegate &native_delegate, MainLoop &mainloop,
-                       NativeProcessProtocolSP &process_sp);
-
-  //------------------------------------------------------------------
-  /// Attach to an existing process. This method will create an concrete
-  /// instance of NativeProcessProtocol, based on the host platform.
-  /// (e.g. NativeProcessLinux on linux, etc.)
-  ///
-  /// @param[in] pid
-  ///     pid of the process locatable
-  ///
-  /// @param[in] native_delegate
-  ///     The delegate that will receive messages regarding the
-  ///     inferior.  Must outlive the NativeProcessProtocol
-  ///     instance.
-  ///
-  /// @param[in] mainloop
-  ///     The mainloop instance with which the process can register
-  ///     callbacks. Must outlive the NativeProcessProtocol
-  ///     instance.
-  ///
-  /// @param[out] process_sp
-  ///     On successful return from the method, this parameter
-  ///     contains the shared pointer to the
-  ///     NativeProcessProtocol that can be used to manipulate
-  ///     the native process.
-  ///
-  /// @return
-  ///     An error object indicating if the operation succeeded,
-  ///     and if not, what error occurred.
-  //------------------------------------------------------------------
-  static Status Attach(lldb::pid_t pid, NativeDelegate &native_delegate,
-                       MainLoop &mainloop, NativeProcessProtocolSP &process_sp);
+  class Factory {
+  public:
+    virtual ~Factory();
+    //------------------------------------------------------------------
+    /// Launch a process for debugging.
+    ///
+    /// @param[in] launch_info
+    ///     Information required to launch the process.
+    ///
+    /// @param[in] native_delegate
+    ///     The delegate that will receive messages regarding the
+    ///     inferior.  Must outlive the NativeProcessProtocol
+    ///     instance.
+    ///
+    /// @param[in] mainloop
+    ///     The mainloop instance with which the process can register
+    ///     callbacks. Must outlive the NativeProcessProtocol
+    ///     instance.
+    ///
+    /// @return
+    ///     A NativeProcessProtocol shared pointer if the operation succeeded or
+    ///     an error object if it failed.
+    //------------------------------------------------------------------
+    virtual llvm::Expected<NativeProcessProtocolSP>
+    Launch(ProcessLaunchInfo &launch_info, NativeDelegate &native_delegate,
+           MainLoop &mainloop) const = 0;
+
+    //------------------------------------------------------------------
+    /// Attach to an existing process.
+    ///
+    /// @param[in] pid
+    ///     pid of the process locatable
+    ///
+    /// @param[in] native_delegate
+    ///     The delegate that will receive messages regarding the
+    ///     inferior.  Must outlive the NativeProcessProtocol
+    ///     instance.
+    ///
+    /// @param[in] mainloop
+    ///     The mainloop instance with which the process can register
+    ///     callbacks. Must outlive the NativeProcessProtocol
+    ///     instance.
+    ///
+    /// @return
+    ///     A NativeProcessProtocol shared pointer if the operation succeeded or
+    ///     an error object if it failed.
+    //------------------------------------------------------------------
+    virtual llvm::Expected<NativeProcessProtocolSP>
+    Attach(lldb::pid_t pid, NativeDelegate &native_delegate,
+           MainLoop &mainloop) const = 0;
+  };
 
   //------------------------------------------------------------------
   /// StartTracing API for starting a tracing instance with the
@@ -413,10 +403,10 @@ protected:
   lldb::pid_t m_pid;
 
   std::vector<NativeThreadProtocolSP> m_threads;
-  lldb::tid_t m_current_thread_id;
+  lldb::tid_t m_current_thread_id = LLDB_INVALID_THREAD_ID;
   mutable std::recursive_mutex m_threads_mutex;
 
-  lldb::StateType m_state;
+  lldb::StateType m_state = lldb::eStateInvalid;
   mutable std::recursive_mutex m_state_mutex;
 
   llvm::Optional<WaitStatus> m_exit_status;
@@ -427,7 +417,7 @@ protected:
   NativeWatchpointList m_watchpoint_list;
   HardwareBreakpointMap m_hw_breakpoints_map;
   int m_terminal_fd;
-  uint32_t m_stop_id;
+  uint32_t m_stop_id = 0;
 
   // Set of signal numbers that LLDB directly injects back to inferior
   // without stopping it.
@@ -438,7 +428,8 @@ protected:
   // then the process should be attached to. When attaching to a process
   // lldb_private::Host calls should be used to locate the process to attach to,
   // and then this function should be called.
-  NativeProcessProtocol(lldb::pid_t pid);
+  NativeProcessProtocol(lldb::pid_t pid, int terminal_fd,
+                        NativeDelegate &delegate);
 
   // -----------------------------------------------------------
   // Internal interface for state handling
diff --git a/lit/lit.cfg b/lit/lit.cfg
index a3d5f9ca7524..8dea61b27169 100644
--- a/lit/lit.cfg
+++ b/lit/lit.cfg
@@ -95,8 +95,8 @@ if config.test_exec_root is None:
         lit_config.fatal('No site specific configuration available!')
 
     # Get the source and object roots.
-    llvm_src_root = lit.util.capture(['llvm-config', '--src-root']).strip()
-    llvm_obj_root = lit.util.capture(['llvm-config', '--obj-root']).strip()
+    llvm_src_root = subprocess.check_output(['llvm-config', '--src-root']).strip()
+    llvm_obj_root = subprocess.check_output(['llvm-config', '--obj-root']).strip()
     lldb_src_root = os.path.join(llvm_src_root, "tools", "lldb")
     lldb_obj_root = os.path.join(llvm_obj_root, "tools", "lldb")
 
@@ -132,7 +132,7 @@ if not os.path.exists(config.cxx):
 
 if platform.system() in ['Darwin']:
     try:
-        out = lit.util.capture(['xcrun', '--show-sdk-path']).strip()
+        out = subprocess.check_output(['xcrun', '--show-sdk-path']).strip()
         res = 0
     except OSError:
         res = -1
diff --git a/lldb.xcodeproj/project.pbxproj b/lldb.xcodeproj/project.pbxproj
index 8c59fc888412..8353da30bd8e 100644
--- a/lldb.xcodeproj/project.pbxproj
+++ b/lldb.xcodeproj/project.pbxproj
@@ -868,6 +868,8 @@
 		966C6B7C18E6A56A0093F5EC /* libz.dylib in Frameworks */ = {isa = PBXBuildFile; fileRef = 966C6B7818E6A56A0093F5EC /* libz.dylib */; };
 		9694FA711B32AA64005EBB16 /* ABISysV_mips.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 9694FA6F1B32AA64005EBB16 /* ABISysV_mips.cpp */; };
 		9A0FDEA71E8EF5110086B2F5 /* RegisterContextLinux_mips.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 9A0FDE971E8EF5010086B2F5 /* RegisterContextLinux_mips.cpp */; };
+		9A1542F91F0EE48600DEA1D8 /* MockTildeExpressionResolver.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 9A1542F51F0EE44000DEA1D8 /* MockTildeExpressionResolver.cpp */; };
+		9A1542FA1F0EE48600DEA1D8 /* TestUtilities.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 9A1542F71F0EE44000DEA1D8 /* TestUtilities.cpp */; };
 		9A19A6AF1163BBB200E0D453 /* SBValue.h in Headers */ = {isa = PBXBuildFile; fileRef = 9A19A6A51163BB7E00E0D453 /* SBValue.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		9A19A6B01163BBB300E0D453 /* SBValue.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 9A19A6AD1163BB9800E0D453 /* SBValue.cpp */; };
 		9A1E595C1EB2B141002206A5 /* SBTrace.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 9A1E59521EB2B0B9002206A5 /* SBTrace.cpp */; };
@@ -2815,6 +2817,11 @@
 		9A0FDE991E8EF5010086B2F5 /* RegisterInfos_arm.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = RegisterInfos_arm.h; path = Utility/RegisterInfos_arm.h; sourceTree = "<group>"; };
 		9A0FDE9A1E8EF5010086B2F5 /* RegisterInfos_arm64.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = RegisterInfos_arm64.h; path = Utility/RegisterInfos_arm64.h; sourceTree = "<group>"; };
 		9A0FDE9B1E8EF5010086B2F5 /* RegisterInfos_mips.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = RegisterInfos_mips.h; path = Utility/RegisterInfos_mips.h; sourceTree = "<group>"; };
+		9A1542F41F0EE44000DEA1D8 /* CMakeLists.txt */ = {isa = PBXFileReference; lastKnownFileType = text; path = CMakeLists.txt; sourceTree = "<group>"; };
+		9A1542F51F0EE44000DEA1D8 /* MockTildeExpressionResolver.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = MockTildeExpressionResolver.cpp; sourceTree = "<group>"; };
+		9A1542F61F0EE44000DEA1D8 /* MockTildeExpressionResolver.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = MockTildeExpressionResolver.h; sourceTree = "<group>"; };
+		9A1542F71F0EE44000DEA1D8 /* TestUtilities.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = TestUtilities.cpp; sourceTree = "<group>"; };
+		9A1542F81F0EE44000DEA1D8 /* TestUtilities.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = TestUtilities.h; sourceTree = "<group>"; };
 		9A19A6A51163BB7E00E0D453 /* SBValue.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = SBValue.h; path = include/lldb/API/SBValue.h; sourceTree = "<group>"; };
 		9A19A6AD1163BB9800E0D453 /* SBValue.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SBValue.cpp; path = source/API/SBValue.cpp; sourceTree = "<group>"; };
 		9A1E59521EB2B0B9002206A5 /* SBTrace.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = SBTrace.cpp; path = source/API/SBTrace.cpp; sourceTree = "<group>"; };
@@ -3305,6 +3312,7 @@
 		2321F9421BDD343A00BA9A93 /* Utility */ = {
 			isa = PBXGroup;
 			children = (
+				9A1542F31F0EE44000DEA1D8 /* Helpers */,
 				2321F9431BDD346100BA9A93 /* CMakeLists.txt */,
 				23CB15041D66CD9200EDDDE1 /* Inputs */,
 				2321F9441BDD346100BA9A93 /* StringExtractorTest.cpp */,
@@ -6216,6 +6224,18 @@
 			name = "SysV-mips";
 			sourceTree = "<group>";
 		};
+		9A1542F31F0EE44000DEA1D8 /* Helpers */ = {
+			isa = PBXGroup;
+			children = (
+				9A1542F41F0EE44000DEA1D8 /* CMakeLists.txt */,
+				9A1542F51F0EE44000DEA1D8 /* MockTildeExpressionResolver.cpp */,
+				9A1542F61F0EE44000DEA1D8 /* MockTildeExpressionResolver.h */,
+				9A1542F71F0EE44000DEA1D8 /* TestUtilities.cpp */,
+				9A1542F81F0EE44000DEA1D8 /* TestUtilities.h */,
+			);
+			path = Helpers;
+			sourceTree = "<group>";
+		};
 		AE44FB371BB35A2E0033EB62 /* Go */ = {
 			isa = PBXGroup;
 			children = (
@@ -7003,12 +7023,14 @@
 				23CB15371D66DA9300EDDDE1 /* PythonTestSuite.cpp in Sources */,
 				23E2E5321D903832006F38BB /* BreakpointIDTest.cpp in Sources */,
 				23CB15381D66DA9300EDDDE1 /* PythonExceptionStateTests.cpp in Sources */,
+				9A1542F91F0EE48600DEA1D8 /* MockTildeExpressionResolver.cpp in Sources */,
 				23CB15391D66DA9300EDDDE1 /* DataExtractorTest.cpp in Sources */,
 				23CB153A1D66DA9300EDDDE1 /* GDBRemoteClientBaseTest.cpp in Sources */,
 				23CB153B1D66DA9300EDDDE1 /* SocketTest.cpp in Sources */,
 				23CB153C1D66DA9300EDDDE1 /* TestArgs.cpp in Sources */,
 				23CB153D1D66DA9300EDDDE1 /* GDBRemoteCommunicationClientTest.cpp in Sources */,
 				23CB153E1D66DA9300EDDDE1 /* PythonDataObjectsTests.cpp in Sources */,
+				9A1542FA1F0EE48600DEA1D8 /* TestUtilities.cpp in Sources */,
 				23CB153F1D66DA9300EDDDE1 /* SymbolsTest.cpp in Sources */,
 				AFEC5FD81D94F9380076A480 /* Testx86AssemblyInspectionEngine.cpp in Sources */,
 				23CB15401D66DA9300EDDDE1 /* TestClangASTContext.cpp in Sources */,
@@ -8256,7 +8278,7 @@
 					"$(LLVM_SOURCE_DIR)/tools/clang/include",
 					"$(LLVM_BUILD_DIR)/$(LLVM_BUILD_DIR_ARCH)/tools/clang/include",
 				);
-				LLDB_GTESTS_CFLAGS = "-I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
+				LLDB_GTESTS_CFLAGS = "-I ${SOURCE_ROOT} -I $(LLVM_SOURCE_DIR)/utils/unittest/googlemock/include -I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
 				LLDB_GTESTS_LDFLAGS = "$(LLVM_BUILD_DIR)/x86_64/lib/libgtest.a -L $(PYTHON_FRAMEWORK_PATH)/Versions/$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)/lib -l python$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)";
 				OTHER_CFLAGS = (
 					"-fno-rtti",
@@ -8298,7 +8320,7 @@
 					"$(LLVM_SOURCE_DIR)/tools/clang/include",
 					"$(LLVM_BUILD_DIR)/$(LLVM_BUILD_DIR_ARCH)/tools/clang/include",
 				);
-				LLDB_GTESTS_CFLAGS = "-I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
+				LLDB_GTESTS_CFLAGS = "-I ${SOURCE_ROOT} -I $(LLVM_SOURCE_DIR)/utils/unittest/googlemock/include -I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
 				LLDB_GTESTS_LDFLAGS = "$(LLVM_BUILD_DIR)/x86_64/lib/libgtest.a -L $(PYTHON_FRAMEWORK_PATH)/Versions/$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)/lib -l python$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)";
 				OTHER_CFLAGS = (
 					"-fno-rtti",
@@ -8340,7 +8362,7 @@
 					"$(LLVM_SOURCE_DIR)/tools/clang/include",
 					"$(LLVM_BUILD_DIR)/$(LLVM_BUILD_DIR_ARCH)/tools/clang/include",
 				);
-				LLDB_GTESTS_CFLAGS = "-I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
+				LLDB_GTESTS_CFLAGS = "-I ${SOURCE_ROOT} -I $(LLVM_SOURCE_DIR)/utils/unittest/googlemock/include -I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
 				LLDB_GTESTS_LDFLAGS = "$(LLVM_BUILD_DIR)/x86_64/lib/libgtest.a -L $(PYTHON_FRAMEWORK_PATH)/Versions/$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)/lib -l python$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)";
 				OTHER_CFLAGS = (
 					"-fno-rtti",
@@ -8382,7 +8404,7 @@
 					"$(LLVM_SOURCE_DIR)/tools/clang/include",
 					"$(LLVM_BUILD_DIR)/$(LLVM_BUILD_DIR_ARCH)/tools/clang/include",
 				);
-				LLDB_GTESTS_CFLAGS = "-I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
+				LLDB_GTESTS_CFLAGS = "-I ${SOURCE_ROOT} -I $(LLVM_SOURCE_DIR)/utils/unittest/googlemock/include -I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
 				LLDB_GTESTS_LDFLAGS = "$(LLVM_BUILD_DIR)/x86_64/lib/libgtest.a -L $(PYTHON_FRAMEWORK_PATH)/Versions/$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)/lib -l python$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)";
 				OTHER_CFLAGS = (
 					"-fno-rtti",
@@ -8424,7 +8446,7 @@
 					"$(LLVM_SOURCE_DIR)/tools/clang/include",
 					"$(LLVM_BUILD_DIR)/$(LLVM_BUILD_DIR_ARCH)/tools/clang/include",
 				);
-				LLDB_GTESTS_CFLAGS = "-I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
+				LLDB_GTESTS_CFLAGS = "-I ${SOURCE_ROOT} -I $(LLVM_SOURCE_DIR)/utils/unittest/googlemock/include -I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
 				LLDB_GTESTS_LDFLAGS = "$(LLVM_BUILD_DIR)/x86_64/lib/libgtest.a -L $(PYTHON_FRAMEWORK_PATH)/Versions/$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)/lib -l python$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)";
 				OTHER_CFLAGS = (
 					"-fno-rtti",
@@ -8466,7 +8488,7 @@
 					"$(LLVM_SOURCE_DIR)/tools/clang/include",
 					"$(LLVM_BUILD_DIR)/$(LLVM_BUILD_DIR_ARCH)/tools/clang/include",
 				);
-				LLDB_GTESTS_CFLAGS = "-I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
+				LLDB_GTESTS_CFLAGS = "-I ${SOURCE_ROOT} -I $(LLVM_SOURCE_DIR)/utils/unittest/googlemock/include -I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
 				LLDB_GTESTS_LDFLAGS = "$(LLVM_BUILD_DIR)/x86_64/lib/libgtest.a -L $(PYTHON_FRAMEWORK_PATH)/Versions/$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)/lib -l python$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)";
 				OTHER_CFLAGS = (
 					"-fno-rtti",
@@ -8508,7 +8530,7 @@
 					"$(LLVM_SOURCE_DIR)/tools/clang/include",
 					"$(LLVM_BUILD_DIR)/$(LLVM_BUILD_DIR_ARCH)/tools/clang/include",
 				);
-				LLDB_GTESTS_CFLAGS = "-I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
+				LLDB_GTESTS_CFLAGS = "-I ${SOURCE_ROOT} -I $(LLVM_SOURCE_DIR)/utils/unittest/googlemock/include -I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
 				LLDB_GTESTS_LDFLAGS = "$(LLVM_BUILD_DIR)/x86_64/lib/libgtest.a -L $(PYTHON_FRAMEWORK_PATH)/Versions/$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)/lib -l python$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)";
 				OTHER_CFLAGS = (
 					"-fno-rtti",
@@ -8550,7 +8572,7 @@
 					"$(LLVM_SOURCE_DIR)/tools/clang/include",
 					"$(LLVM_BUILD_DIR)/$(LLVM_BUILD_DIR_ARCH)/tools/clang/include",
 				);
-				LLDB_GTESTS_CFLAGS = "-I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
+				LLDB_GTESTS_CFLAGS = "-I ${SOURCE_ROOT} -I $(LLVM_SOURCE_DIR)/utils/unittest/googlemock/include -I $(LLVM_SOURCE_DIR)/utils/unittest/googletest/include -I $(LLVM_SOURCE_DIR)/include -I $(LLVM_BUILD_DIR)/x86_64/include -I include -I source -I $(PYTHON_FRAMEWORK_PATH)/Headers";
 				LLDB_GTESTS_LDFLAGS = "$(LLVM_BUILD_DIR)/x86_64/lib/libgtest.a -L $(PYTHON_FRAMEWORK_PATH)/Versions/$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)/lib -l python$(PYTHON_VERSION_MAJOR).$(PYTHON_VERSION_MINOR)";
 				OTHER_CFLAGS = (
 					"-fno-rtti",
diff --git a/packages/Python/lldbsuite/test/expression_command/call-restarts/TestCallThatRestarts.py b/packages/Python/lldbsuite/test/expression_command/call-restarts/TestCallThatRestarts.py
index 0b9ad0ed6323..5eb7b309c94a 100644
--- a/packages/Python/lldbsuite/test/expression_command/call-restarts/TestCallThatRestarts.py
+++ b/packages/Python/lldbsuite/test/expression_command/call-restarts/TestCallThatRestarts.py
@@ -48,28 +48,8 @@ class ExprCommandThatRestartsTestCase(TestBase):
             "Restored the zeroth frame correctly")
 
     def call_function(self):
-        exe_name = "a.out"
-        exe = os.path.join(os.getcwd(), exe_name)
-
-        target = self.dbg.CreateTarget(exe)
-        self.assertTrue(target, VALID_TARGET)
-        empty = lldb.SBFileSpec()
-        breakpoint = target.BreakpointCreateBySourceRegex(
-            'Stop here in main.', self.main_source_spec)
-        self.assertTrue(breakpoint.GetNumLocations() > 0, VALID_BREAKPOINT)
-
-        # Launch the process, and do not stop at the entry point.
-        process = target.LaunchSimple(
-            None, None, self.get_process_working_directory())
-
-        self.assertTrue(process, PROCESS_IS_VALID)
-
-        # Frame #0 should be at our breakpoint.
-        threads = lldbutil.get_threads_stopped_at_breakpoint(
-            process, breakpoint)
-
-        self.assertTrue(len(threads) == 1)
-        self.thread = threads[0]
+        (target, process, self.thread, bkpt) = lldbutil.run_to_source_breakpoint(self, 
+                                      'Stop here in main.', self.main_source_spec)
 
         # Make sure the SIGCHLD behavior is pass/no-stop/no-notify:
         return_obj = lldb.SBCommandReturnObject()
diff --git a/packages/Python/lldbsuite/test/expression_command/call-throws/TestCallThatThrows.py b/packages/Python/lldbsuite/test/expression_command/call-throws/TestCallThatThrows.py
index e5162609dfa6..f2ec340ac845 100644
--- a/packages/Python/lldbsuite/test/expression_command/call-throws/TestCallThatThrows.py
+++ b/packages/Python/lldbsuite/test/expression_command/call-throws/TestCallThatThrows.py
@@ -37,28 +37,8 @@ class ExprCommandWithThrowTestCase(TestBase):
 
     def call_function(self):
         """Test calling function that throws."""
-        exe_name = "a.out"
-        exe = os.path.join(os.getcwd(), exe_name)
-
-        target = self.dbg.CreateTarget(exe)
-        self.assertTrue(target, VALID_TARGET)
-
-        breakpoint = target.BreakpointCreateBySourceRegex(
-            'I am about to throw.', self.main_source_spec)
-        self.assertTrue(breakpoint.GetNumLocations() > 0, VALID_BREAKPOINT)
-
-        # Launch the process, and do not stop at the entry point.
-        process = target.LaunchSimple(
-            None, None, self.get_process_working_directory())
-
-        self.assertTrue(process, PROCESS_IS_VALID)
-
-        # Frame #0 should be at our breakpoint.
-        threads = lldbutil.get_threads_stopped_at_breakpoint(
-            process, breakpoint)
-
-        self.assertTrue(len(threads) == 1)
-        self.thread = threads[0]
+        (target, process, self.thread, bkpt) = lldbutil.run_to_source_breakpoint(self, 
+                                   'I am about to throw.', self.main_source_spec)
 
         options = lldb.SBExpressionOptions()
         options.SetUnwindOnError(True)
diff --git a/packages/Python/lldbsuite/test/expression_command/char/TestExprsChar.py b/packages/Python/lldbsuite/test/expression_command/char/TestExprsChar.py
index a771e7004c94..74991999d926 100644
--- a/packages/Python/lldbsuite/test/expression_command/char/TestExprsChar.py
+++ b/packages/Python/lldbsuite/test/expression_command/char/TestExprsChar.py
@@ -17,29 +17,14 @@ class ExprCharTestCase(TestBase):
 
         self.main_source = "main.cpp"
         self.main_source_spec = lldb.SBFileSpec(self.main_source)
-        self.exe = os.path.join(os.getcwd(), "a.out")
 
     def do_test(self, dictionary=None):
         """These basic expression commands should work as expected."""
         self.build(dictionary=dictionary)
 
-        target = self.dbg.CreateTarget(self.exe)
-        self.assertTrue(target)
-
-        breakpoint = target.BreakpointCreateBySourceRegex(
-            '// Break here', self.main_source_spec)
-        self.assertTrue(breakpoint)
-
-        # Launch the process, and do not stop at the entry point.
-        process = target.LaunchSimple(
-            None, None, self.get_process_working_directory())
-        self.assertTrue(process)
-
-        threads = lldbutil.get_threads_stopped_at_breakpoint(
-            process, breakpoint)
-        self.assertEqual(len(threads), 1)
-
-        frame = threads[0].GetFrameAtIndex(0)
+        (target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint(self, 
+                                          '// Break here', self.main_source_spec)
+        frame = thread.GetFrameAtIndex(0)
 
         value = frame.EvaluateExpression("foo(c)")
         self.assertTrue(value.IsValid())
diff --git a/packages/Python/lldbsuite/test/expression_command/fixits/TestFixIts.py b/packages/Python/lldbsuite/test/expression_command/fixits/TestFixIts.py
index 418c5325ad08..4b096149e728 100644
--- a/packages/Python/lldbsuite/test/expression_command/fixits/TestFixIts.py
+++ b/packages/Python/lldbsuite/test/expression_command/fixits/TestFixIts.py
@@ -37,28 +37,8 @@ class ExprCommandWithFixits(TestBase):
 
     def try_expressions(self):
         """Test calling expressions with errors that can be fixed by the FixIts."""
-        exe_name = "a.out"
-        exe = os.path.join(os.getcwd(), exe_name)
-
-        target = self.dbg.CreateTarget(exe)
-        self.assertTrue(target, VALID_TARGET)
-
-        breakpoint = target.BreakpointCreateBySourceRegex(
-            'Stop here to evaluate expressions', self.main_source_spec)
-        self.assertTrue(breakpoint.GetNumLocations() > 0, VALID_BREAKPOINT)
-
-        # Launch the process, and do not stop at the entry point.
-        process = target.LaunchSimple(
-            None, None, self.get_process_working_directory())
-
-        self.assertTrue(process, PROCESS_IS_VALID)
-
-        # Frame #0 should be at our breakpoint.
-        threads = lldbutil.get_threads_stopped_at_breakpoint(
-            process, breakpoint)
-
-        self.assertTrue(len(threads) == 1)
-        self.thread = threads[0]
+        (target, process, self.thread, bkpt) = lldbutil.run_to_source_breakpoint(self, 
+                                        'Stop here to evaluate expressions', self.main_source_spec)
 
         options = lldb.SBExpressionOptions()
         options.SetAutoApplyFixIts(True)
diff --git a/packages/Python/lldbsuite/test/expression_command/issue_11588/Test11588.py b/packages/Python/lldbsuite/test/expression_command/issue_11588/Test11588.py
index afb497e04b5b..a2d68cffe548 100644
--- a/packages/Python/lldbsuite/test/expression_command/issue_11588/Test11588.py
+++ b/packages/Python/lldbsuite/test/expression_command/issue_11588/Test11588.py
@@ -32,26 +32,9 @@ class Issue11581TestCase(TestBase):
         """valobj.AddressOf() should return correct values."""
         self.build()
 
-        exe = os.path.join(os.getcwd(), "a.out")
-
-        target = self.dbg.CreateTarget(exe)
-        self.assertTrue(target, VALID_TARGET)
-
-        breakpoint = target.BreakpointCreateBySourceRegex(
-            'Set breakpoint here.', lldb.SBFileSpec("main.cpp", False))
-
-        process = target.LaunchSimple(
-            None, None, self.get_process_working_directory())
-        self.assertTrue(process, "Created a process.")
-        self.assertTrue(
-            process.GetState() == lldb.eStateStopped,
-            "Stopped it too.")
-
-        thread_list = lldbutil.get_threads_stopped_at_breakpoint(
-            process, breakpoint)
-        self.assertTrue(len(thread_list) == 1)
-        thread = thread_list[0]
-
+        (target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint(self, 
+                                              'Set breakpoint here.', 
+                                              lldb.SBFileSpec("main.cpp", False))
         self.runCmd("command script import --allow-reload s11588.py")
         self.runCmd(
             "type synthetic add --python-class s11588.Issue11581SyntheticProvider StgClosure")
diff --git a/packages/Python/lldbsuite/test/expression_command/macros/TestMacros.py b/packages/Python/lldbsuite/test/expression_command/macros/TestMacros.py
index 70b862bf4867..817f6cb3944a 100644
--- a/packages/Python/lldbsuite/test/expression_command/macros/TestMacros.py
+++ b/packages/Python/lldbsuite/test/expression_command/macros/TestMacros.py
@@ -30,32 +30,8 @@ class TestMacros(TestBase):
         src_file_spec = lldb.SBFileSpec(src_file)
         self.assertTrue(src_file_spec.IsValid(), "Main source file")
 
-        # Get the path of the executable
-        cwd = os.getcwd()
-        exe_file = "a.out"
-        exe_path = os.path.join(cwd, exe_file)
-
-        # Load the executable
-        target = self.dbg.CreateTarget(exe_path)
-        self.assertTrue(target.IsValid(), VALID_TARGET)
-
-        # Set breakpoints
-        bp1 = target.BreakpointCreateBySourceRegex("Break here", src_file_spec)
-        self.assertTrue(
-            bp1.IsValid() and bp1.GetNumLocations() >= 1,
-            VALID_BREAKPOINT)
-
-        # Launch the process
-        process = target.LaunchSimple(
-            None, None, self.get_process_working_directory())
-        self.assertTrue(process.IsValid(), PROCESS_IS_VALID)
-
-        # Get the thread of the process
-        self.assertTrue(
-            process.GetState() == lldb.eStateStopped,
-            PROCESS_STOPPED)
-        thread = lldbutil.get_stopped_thread(
-            process, lldb.eStopReasonBreakpoint)
+        (target, process, thread, bp1) = lldbutil.run_to_source_breakpoint(
+            self, "Break here", src_file_spec)
 
         # Get frame for current thread
         frame = thread.GetSelectedFrame()
diff --git a/packages/Python/lldbsuite/test/expression_command/options/TestExprOptions.py b/packages/Python/lldbsuite/test/expression_command/options/TestExprOptions.py
index 0d1a17352a3f..b4e9a8bfeab8 100644
--- a/packages/Python/lldbsuite/test/expression_command/options/TestExprOptions.py
+++ b/packages/Python/lldbsuite/test/expression_command/options/TestExprOptions.py
@@ -37,25 +37,10 @@ class ExprOptionsTestCase(TestBase):
         # Set debugger into synchronous mode
         self.dbg.SetAsync(False)
 
-        # Create a target by the debugger.
-        target = self.dbg.CreateTarget(self.exe)
-        self.assertTrue(target, VALID_TARGET)
+        (target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint(
+            self, '// breakpoint_in_main', self.main_source_spec)
 
-        # Set breakpoints inside main.
-        breakpoint = target.BreakpointCreateBySourceRegex(
-            '// breakpoint_in_main', self.main_source_spec)
-        self.assertTrue(breakpoint)
-
-        # Now launch the process, and do not stop at entry point.
-        process = target.LaunchSimple(
-            None, None, self.get_process_working_directory())
-        self.assertTrue(process, PROCESS_IS_VALID)
-
-        threads = lldbutil.get_threads_stopped_at_breakpoint(
-            process, breakpoint)
-        self.assertEqual(len(threads), 1)
-
-        frame = threads[0].GetFrameAtIndex(0)
+        frame = thread.GetFrameAtIndex(0)
         options = lldb.SBExpressionOptions()
 
         # test --language on C++ expression using the SB API's
diff --git a/packages/Python/lldbsuite/test/expression_command/save_jit_objects/TestSaveJITObjects.py b/packages/Python/lldbsuite/test/expression_command/save_jit_objects/TestSaveJITObjects.py
index 7f796971d0ed..f6938b1ea98b 100644
--- a/packages/Python/lldbsuite/test/expression_command/save_jit_objects/TestSaveJITObjects.py
+++ b/packages/Python/lldbsuite/test/expression_command/save_jit_objects/TestSaveJITObjects.py
@@ -31,17 +31,10 @@ class SaveJITObjectsTestCase(TestBase):
         src_file = "main.c"
         src_file_spec = lldb.SBFileSpec(src_file)
   
-        exe_path = os.path.join(os.getcwd(), "a.out")
-        target = self.dbg.CreateTarget(exe_path)
+        (target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint(
+            self, "break", src_file_spec)
 
-        breakpoint = target.BreakpointCreateBySourceRegex(
-            "break", src_file_spec)
-
-        process = target.LaunchSimple(None, None,
-                                      self.get_process_working_directory())
-
-        thread = process.GetSelectedThread()
-        frame = thread.GetSelectedFrame()
+        frame = thread.frames[0]
 
         cleanJITFiles()
         frame.EvaluateExpression("(void*)malloc(0x1)")
diff --git a/packages/Python/lldbsuite/test/expression_command/timeout/TestCallWithTimeout.py b/packages/Python/lldbsuite/test/expression_command/timeout/TestCallWithTimeout.py
index 29c03b1d7ef9..7862477001ea 100644
--- a/packages/Python/lldbsuite/test/expression_command/timeout/TestCallWithTimeout.py
+++ b/packages/Python/lldbsuite/test/expression_command/timeout/TestCallWithTimeout.py
@@ -25,36 +25,14 @@ class ExprCommandWithTimeoutsTestCase(TestBase):
     @expectedFlakeyFreeBSD("llvm.org/pr19605")
     @expectedFailureAll(
         oslist=[
-            "windows",
-            "macosx"],
+            "windows"],
         bugnumber="llvm.org/pr21765")
     def test(self):
         """Test calling std::String member function."""
         self.build()
 
-        exe_name = "a.out"
-        exe = os.path.join(os.getcwd(), exe_name)
-
-        target = self.dbg.CreateTarget(exe)
-        self.assertTrue(target, VALID_TARGET)
-
-        breakpoint = target.BreakpointCreateBySourceRegex(
-            'stop here in main.', self.main_source_spec)
-        self.assertTrue(breakpoint, VALID_BREAKPOINT)
-        self.runCmd("breakpoint list")
-
-        # Launch the process, and do not stop at the entry point.
-        process = target.LaunchSimple(
-            None, None, self.get_process_working_directory())
-
-        self.assertTrue(process, PROCESS_IS_VALID)
-
-        # Frame #0 should be on self.step_out_of_malloc.
-        threads = lldbutil.get_threads_stopped_at_breakpoint(
-            process, breakpoint)
-
-        self.assertTrue(len(threads) == 1)
-        thread = threads[0]
+        (target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint(
+            self, 'stop here in main.', self.main_source_spec)
 
         # First set the timeout too short, and make sure we fail.
         options = lldb.SBExpressionOptions()
diff --git a/packages/Python/lldbsuite/test/functionalities/mtc/simple/Makefile b/packages/Python/lldbsuite/test/functionalities/mtc/simple/Makefile
new file mode 100644
index 000000000000..5665652329dc
--- /dev/null
+++ b/packages/Python/lldbsuite/test/functionalities/mtc/simple/Makefile
@@ -0,0 +1,6 @@
+LEVEL = ../../../make
+
+OBJC_SOURCES := main.m
+LDFLAGS = $(CFLAGS) -lobjc -framework Foundation -framework AppKit
+
+include $(LEVEL)/Makefile.rules
diff --git a/packages/Python/lldbsuite/test/functionalities/mtc/simple/TestMTCSimple.py b/packages/Python/lldbsuite/test/functionalities/mtc/simple/TestMTCSimple.py
new file mode 100644
index 000000000000..6a779ecfac5b
--- /dev/null
+++ b/packages/Python/lldbsuite/test/functionalities/mtc/simple/TestMTCSimple.py
@@ -0,0 +1,57 @@
+"""
+Tests basic Main Thread Checker support (detecting a main-thread-only violation).
+"""
+
+import os
+import time
+import lldb
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+import lldbsuite.test.lldbutil as lldbutil
+from lldbsuite.test.lldbplatformutil import *
+import json
+
+
+class MTCSimpleTestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    @skipUnlessDarwin
+    def test(self):
+        self.mtc_dylib_path = findMainThreadCheckerDylib()
+        if self.mtc_dylib_path == "":
+            self.skipTest("This test requires libMainThreadChecker.dylib.")
+
+        self.build()
+        self.mtc_tests()
+
+    def setUp(self):
+        # Call super's setUp().
+        TestBase.setUp(self)
+
+    def mtc_tests(self):
+        # Load the test
+        exe = os.path.join(os.getcwd(), "a.out")
+        self.expect("file " + exe, patterns=["Current executable set to .*a.out"])
+
+        self.runCmd("env DYLD_INSERT_LIBRARIES=%s" % self.mtc_dylib_path)
+        self.runCmd("run")
+
+        process = self.dbg.GetSelectedTarget().process
+        thread = process.GetSelectedThread()
+        frame = thread.GetSelectedFrame()
+
+        self.expect("thread info", substrs=['stop reason = -[NSView superview] must be used from main thread only'])
+
+        self.expect(
+            "thread info -s",
+            substrs=["instrumentation_class", "api_name", "class_name", "selector", "description"])
+        self.assertEqual(thread.GetStopReason(), lldb.eStopReasonInstrumentation)
+        output_lines = self.res.GetOutput().split('\n')
+        json_line = '\n'.join(output_lines[2:])
+        data = json.loads(json_line)
+        self.assertEqual(data["instrumentation_class"], "MainThreadChecker")
+        self.assertEqual(data["api_name"], "-[NSView superview]")
+        self.assertEqual(data["class_name"], "NSView")
+        self.assertEqual(data["selector"], "superview")
+        self.assertEqual(data["description"], "-[NSView superview] must be used from main thread only")
diff --git a/packages/Python/lldbsuite/test/functionalities/mtc/simple/main.m b/packages/Python/lldbsuite/test/functionalities/mtc/simple/main.m
new file mode 100644
index 000000000000..651347cf74ee
--- /dev/null
+++ b/packages/Python/lldbsuite/test/functionalities/mtc/simple/main.m
@@ -0,0 +1,15 @@
+#import <Foundation/Foundation.h>
+#import <AppKit/AppKit.h>
+
+int main() {
+  NSView *view = [[NSView alloc] init];
+  dispatch_group_t g = dispatch_group_create();
+  dispatch_group_enter(g);
+  [NSThread detachNewThreadWithBlock:^{
+    @autoreleasepool {
+      [view superview];
+    }
+    dispatch_group_leave(g);
+  }];
+  dispatch_group_wait(g, DISPATCH_TIME_FOREVER);
+}
diff --git a/packages/Python/lldbsuite/test/functionalities/return-value/TestReturnValue.py b/packages/Python/lldbsuite/test/functionalities/return-value/TestReturnValue.py
index cf435a4aae91..1750bd31b3df 100644
--- a/packages/Python/lldbsuite/test/functionalities/return-value/TestReturnValue.py
+++ b/packages/Python/lldbsuite/test/functionalities/return-value/TestReturnValue.py
@@ -31,8 +31,6 @@ class ReturnValueTestCase(TestBase):
             "<=",
             "3.6"],
         archs=["i386"])
-    @expectedFailureAll(compiler="clang", compiler_version=["<=", "5.0.300080"],
-            triple='.*-android', archs=["i386"])
     @expectedFailureAll(oslist=["windows"], bugnumber="llvm.org/pr24778")
     @add_test_categories(['pyapi'])
     def test_with_python(self):
diff --git a/packages/Python/lldbsuite/test/functionalities/signal/raise/TestRaise.py b/packages/Python/lldbsuite/test/functionalities/signal/raise/TestRaise.py
index efadea51f669..79175562fe7a 100644
--- a/packages/Python/lldbsuite/test/functionalities/signal/raise/TestRaise.py
+++ b/packages/Python/lldbsuite/test/functionalities/signal/raise/TestRaise.py
@@ -16,6 +16,7 @@ from lldbsuite.test import lldbutil
 class RaiseTestCase(TestBase):
 
     mydir = TestBase.compute_mydir(__file__)
+    NO_DEBUG_INFO_TESTCASE = True
 
     def test_sigstop(self):
         self.build()
@@ -29,6 +30,10 @@ class RaiseTestCase(TestBase):
         self.build()
         self.signal_test('SIGRTMIN', True)
 
+    def test_sigtrap(self):
+        self.build()
+        self.signal_test('SIGTRAP', True)
+
     def launch(self, target, signal):
         # launch the process, do not stop at entry point.
         process = target.LaunchSimple(
diff --git a/packages/Python/lldbsuite/test/functionalities/signal/raise/main.c b/packages/Python/lldbsuite/test/functionalities/signal/raise/main.c
index 8827174e758e..4203fe5d4c89 100644
--- a/packages/Python/lldbsuite/test/functionalities/signal/raise/main.c
+++ b/packages/Python/lldbsuite/test/functionalities/signal/raise/main.c
@@ -10,6 +10,11 @@ void handler(int signo)
 
 int main (int argc, char *argv[])
 {
+    if (signal(SIGTRAP, handler) == SIG_ERR)
+    {
+        perror("signal(SIGTRAP)");
+        return 1;
+    }
 #ifndef __APPLE__
     // Real time signals not supported on apple platforms.
     if (signal(SIGRTMIN, handler) == SIG_ERR)
@@ -27,6 +32,8 @@ int main (int argc, char *argv[])
 
     if (strcmp(argv[1], "SIGSTOP") == 0)
         raise(SIGSTOP);
+    else if (strcmp(argv[1], "SIGTRAP") == 0)
+        raise(SIGTRAP);
 #ifndef __APPLE__
     else if (strcmp(argv[1], "SIGRTMIN") == 0)
         raise(SIGRTMIN);
diff --git a/packages/Python/lldbsuite/test/functionalities/ubsan/user-expression/Makefile b/packages/Python/lldbsuite/test/functionalities/ubsan/user-expression/Makefile
new file mode 100644
index 000000000000..6e7d19b6f48c
--- /dev/null
+++ b/packages/Python/lldbsuite/test/functionalities/ubsan/user-expression/Makefile
@@ -0,0 +1,6 @@
+LEVEL = ../../../make
+
+C_SOURCES := main.c
+CFLAGS_EXTRAS := -fsanitize=undefined -g
+
+include $(LEVEL)/Makefile.rules
diff --git a/packages/Python/lldbsuite/test/functionalities/ubsan/user-expression/TestUbsanUserExpression.py b/packages/Python/lldbsuite/test/functionalities/ubsan/user-expression/TestUbsanUserExpression.py
new file mode 100644
index 000000000000..a5e5f572a979
--- /dev/null
+++ b/packages/Python/lldbsuite/test/functionalities/ubsan/user-expression/TestUbsanUserExpression.py
@@ -0,0 +1,49 @@
+"""
+Test that hitting a UBSan issue while running user expression doesn't break the evaluation.
+"""
+
+import os
+import time
+import lldb
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+import lldbsuite.test.lldbutil as lldbutil
+import json
+
+
+class UbsanUserExpressionTestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    @skipUnlessUndefinedBehaviorSanitizer
+    def test(self):
+        self.build()
+        self.ubsan_tests()
+
+    def setUp(self):
+        # Call super's setUp().
+        TestBase.setUp(self)
+        self.line_breakpoint = line_number('main.c', '// breakpoint line')
+
+    def ubsan_tests(self):
+        # Load the test
+        exe = os.path.join(os.getcwd(), "a.out")
+        self.expect(
+            "file " + exe,
+            patterns=["Current executable set to .*a.out"])
+
+        self.runCmd("breakpoint set -f main.c -l %d" % self.line_breakpoint)
+
+        self.runCmd("run")
+
+        process = self.dbg.GetSelectedTarget().process
+        thread = process.GetSelectedThread()
+        frame = thread.GetSelectedFrame()
+
+        self.expect("thread list", STOPPED_DUE_TO_BREAKPOINT,
+                    substrs=['stopped', 'stop reason = breakpoint'])
+
+        self.expect("p foo()", substrs=["(int) $0 = 42"])
+
+        self.expect("thread list", STOPPED_DUE_TO_BREAKPOINT,
+                    substrs=['stopped', 'stop reason = breakpoint'])
diff --git a/packages/Python/lldbsuite/test/functionalities/ubsan/user-expression/main.c b/packages/Python/lldbsuite/test/functionalities/ubsan/user-expression/main.c
new file mode 100644
index 000000000000..4786aaa89b27
--- /dev/null
+++ b/packages/Python/lldbsuite/test/functionalities/ubsan/user-expression/main.c
@@ -0,0 +1,9 @@
+int foo() {
+  int data[4];
+  int x = *(int *)(((char *)&data[0]) + 2);
+  return 42;
+}
+
+int main() {
+  return 0; // breakpoint line
+}
diff --git a/packages/Python/lldbsuite/test/lang/go/types/TestGoASTContext.py b/packages/Python/lldbsuite/test/lang/go/types/TestGoASTContext.py
index 8e158c3e82d4..9571e259629f 100644
--- a/packages/Python/lldbsuite/test/lang/go/types/TestGoASTContext.py
+++ b/packages/Python/lldbsuite/test/lang/go/types/TestGoASTContext.py
@@ -20,6 +20,7 @@ class TestGoASTContext(TestBase):
     @skipIfRemote  # Not remote test suit ready
     @no_debug_info_test
     @skipUnlessGoInstalled
+    @expectedFailureAll(bugnumber="llvm.org/pr33643")
     def test_with_dsym_and_python_api(self):
         """Test GoASTContext dwarf parsing."""
         self.buildGo()
diff --git a/packages/Python/lldbsuite/test/lldbplatformutil.py b/packages/Python/lldbsuite/test/lldbplatformutil.py
index 89ce1d468bd0..4f45643241ed 100644
--- a/packages/Python/lldbsuite/test/lldbplatformutil.py
+++ b/packages/Python/lldbsuite/test/lldbplatformutil.py
@@ -8,6 +8,7 @@ import itertools
 import re
 import subprocess
 import sys
+import os
 
 # Third-party modules
 import six
@@ -140,6 +141,19 @@ def platformIsDarwin():
     return getPlatform() in getDarwinOSTriples()
 
 
+def findMainThreadCheckerDylib():
+    if not platformIsDarwin():
+        return ""
+
+    with os.popen('xcode-select -p') as output:
+        xcode_developer_path = output.read().strip()
+        mtc_dylib_path = '%s/usr/lib/libMainThreadChecker.dylib' % xcode_developer_path
+        if os.path.isfile(mtc_dylib_path):
+            return mtc_dylib_path
+
+    return ""
+
+
 class _PlatformContext(object):
     """Value object class which contains platform-specific options."""
 
diff --git a/packages/Python/lldbsuite/test/lldbutil.py b/packages/Python/lldbsuite/test/lldbutil.py
index 7732dbe6dff3..58a1ead1ea0b 100644
--- a/packages/Python/lldbsuite/test/lldbutil.py
+++ b/packages/Python/lldbsuite/test/lldbutil.py
@@ -725,6 +725,47 @@ def get_crashed_threads(test, process):
             threads.append(thread)
     return threads
 
+def run_to_source_breakpoint(test, bkpt_pattern, source_spec, launch_info = None, exe_name = "a.out", in_cwd = True):
+    """Start up a target, using exe_name as the executable, and run it to 
+       a breakpoint set by source regex bkpt_pattern.
+       If you want to pass in launch arguments or environment variables, you can optionally pass in 
+       an SBLaunchInfo.  If you do that, remember to set the working directory as well.
+       If your executable isn't called a.out, you can pass that in.  And if your executable isn't
+       in the CWD, pass in the absolute path to the executable in exe_name, and set in_cwd to False.
+       If the target isn't valid, the breakpoint isn't found, or hit, the
+       function will cause a testsuite failure.
+       If successful it returns a tuple with the target process and thread that hit the breakpoint."""
+
+    if in_cwd:
+        exe = os.path.join(os.getcwd(), exe_name)
+    
+    # Create the target
+    target = test.dbg.CreateTarget(exe)
+    test.assertTrue(target, "Target: %s is not valid."%(exe_name))
+
+    # Set the breakpoints
+    breakpoint = target.BreakpointCreateBySourceRegex(
+            bkpt_pattern, source_spec)
+    test.assertTrue(breakpoint.GetNumLocations() > 0, 
+                    'No locations found for source breakpoint: "%s"'%(bkpt_pattern))
+
+    # Launch the process, and do not stop at the entry point.
+    if not launch_info:
+        launch_info = lldb.SBLaunchInfo(None)
+        launch_info.SetWorkingDirectory(test.get_process_working_directory())
+
+    error = lldb.SBError()
+    process = target.Launch(launch_info, error)
+
+    test.assertTrue(process, "Could not create a valid process for %s: %s"%(exe_name, error.GetCString()))
+
+    # Frame #0 should be at our breakpoint.
+    threads = get_threads_stopped_at_breakpoint(
+                process, breakpoint)
+
+    test.assertTrue(len(threads) == 1, "Expected 1 thread to stop at breakpoint, %d did."%(len(threads)))
+    thread = threads[0]
+    return (target, process, thread, breakpoint)
 
 def continue_to_breakpoint(process, bkpt):
     """ Continues the process, if it stops, returns the threads stopped at bkpt; otherwise, returns None"""
diff --git a/packages/Python/lldbsuite/test/make/Android.rules b/packages/Python/lldbsuite/test/make/Android.rules
index 0a725494d354..058401f425ad 100644
--- a/packages/Python/lldbsuite/test/make/Android.rules
+++ b/packages/Python/lldbsuite/test/make/Android.rules
@@ -90,7 +90,3 @@ else
 
 	ARCH_LDFLAGS += $(NDK_ROOT)/sources/cxx-stl/gnu-libstdc++/4.9/libs/$(STL_ARCH)/libgnustl_static.a
 endif
-
-ifeq "$(ARCH)" "i386"
-	ARCH_CFLAGS += -mstackrealign
-endif
diff --git a/packages/Python/lldbsuite/test/sample_test/TestSampleTest.py b/packages/Python/lldbsuite/test/sample_test/TestSampleTest.py
index bb34727ff81b..9a1748bbabb5 100644
--- a/packages/Python/lldbsuite/test/sample_test/TestSampleTest.py
+++ b/packages/Python/lldbsuite/test/sample_test/TestSampleTest.py
@@ -25,6 +25,7 @@ class RenameThisSampleTestTestCase(TestBase):
     def test_sample_rename_this(self):
         """There can be many tests in a test case - describe this test here."""
         self.build()
+        self.main_source_file = lldb.SBFileSpec("main.c")
         self.sample_test()
 
     def setUp(self):
@@ -33,40 +34,15 @@ class RenameThisSampleTestTestCase(TestBase):
 
     def sample_test(self):
         """You might use the test implementation in several ways, say so here."""
-        exe = os.path.join(os.getcwd(), "a.out")
 
-        # Create a target by the debugger.
-        target = self.dbg.CreateTarget(exe)
-        self.assertTrue(target, VALID_TARGET)
+        # This function starts a process, "a.out" by default, sets a source
+        # breakpoint, runs to it, and returns the thread, process & target.
+        # It optionally takes an SBLaunchOption argument if you want to pass
+        # arguments or environment variables.
+        (target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint(self,
+                                   "Set a breakpoint here", self.main_source_file) 
 
-        # Now create a breakpoint in main.c at the source matching
-        # "Set a breakpoint here"
-        breakpoint = target.BreakpointCreateBySourceRegex(
-            "Set a breakpoint here", lldb.SBFileSpec("main.c"))
-        self.assertTrue(breakpoint and
-                        breakpoint.GetNumLocations() >= 1,
-                        VALID_BREAKPOINT)
-
-        error = lldb.SBError()
-        # This is the launch info.  If you want to launch with arguments or
-        # environment variables, add them using SetArguments or
-        # SetEnvironmentEntries
-
-        launch_info = lldb.SBLaunchInfo(None)
-        process = target.Launch(launch_info, error)
-        self.assertTrue(process, PROCESS_IS_VALID)
-
-        # Did we hit our breakpoint?
-        from lldbsuite.test.lldbutil import get_threads_stopped_at_breakpoint
-        threads = get_threads_stopped_at_breakpoint(process, breakpoint)
-        self.assertTrue(
-            len(threads) == 1,
-            "There should be a thread stopped at our breakpoint")
-
-        # The hit count for the breakpoint should be 1.
-        self.assertTrue(breakpoint.GetHitCount() == 1)
-
-        frame = threads[0].GetFrameAtIndex(0)
+        frame = thread.GetFrameAtIndex(0)
         test_var = frame.FindVariable("test_var")
         self.assertTrue(test_var.GetError().Success(), "Failed to fetch test_var")
         test_value = test_var.GetValueAsUnsigned()
diff --git a/source/Commands/CommandObjectThread.cpp b/source/Commands/CommandObjectThread.cpp
index 687187b26ccd..6a933df43e14 100644
--- a/source/Commands/CommandObjectThread.cpp
+++ b/source/Commands/CommandObjectThread.cpp
@@ -161,9 +161,9 @@ public:
         // List the common thread ID's
         const std::vector<uint32_t> &thread_index_ids =
             stack.GetUniqueThreadIndexIDs();
-        strm.Printf("%lu thread(s) ", thread_index_ids.size());
+        strm.Format("{0} thread(s) ", thread_index_ids.size());
         for (const uint32_t &thread_index_id : thread_index_ids) {
-          strm.Printf("#%u ", thread_index_id);
+          strm.Format("#{0} ", thread_index_id);
         }
         strm.EOL();
 
@@ -209,7 +209,7 @@ protected:
     Process *process = m_exe_ctx.GetProcessPtr();
     Thread *thread = process->GetThreadList().FindThreadByID(tid).get();
     if (thread == nullptr) {
-      result.AppendErrorWithFormat("Failed to process thread# %llu.\n", tid);
+      result.AppendErrorWithFormatv("Failed to process thread #{0}.\n", tid);
       result.SetStatus(eReturnStatusFailed);
       return false;
     }
diff --git a/source/Core/DumpDataExtractor.cpp b/source/Core/DumpDataExtractor.cpp
index 2b7abd60f8bc..c2a9115c3068 100644
--- a/source/Core/DumpDataExtractor.cpp
+++ b/source/Core/DumpDataExtractor.cpp
@@ -154,7 +154,8 @@ lldb::offset_t lldb_private::DumpDataExtractor(
       target_sp = exe_scope->CalculateTarget();
     if (target_sp) {
       DisassemblerSP disassembler_sp(Disassembler::FindPlugin(
-          target_sp->GetArchitecture(), nullptr, nullptr));
+          target_sp->GetArchitecture(),
+          target_sp->GetDisassemblyFlavor(), nullptr));
       if (disassembler_sp) {
         lldb::addr_t addr = base_addr + start_offset;
         lldb_private::Address so_addr;
diff --git a/source/Host/common/File.cpp b/source/Host/common/File.cpp
index 3de93ebc220b..90a4462c6ca9 100644
--- a/source/Host/common/File.cpp
+++ b/source/Host/common/File.cpp
@@ -24,10 +24,12 @@
 #endif
 
 #include "llvm/Support/ConvertUTF.h"
+#include "llvm/Support/Errno.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Process.h" // for llvm::sys::Process::FileDescriptorHasColors()
 
 #include "lldb/Host/Config.h"
+#include "lldb/Host/Host.h"
 #include "lldb/Utility/DataBufferHeap.h"
 #include "lldb/Utility/FileSpec.h"
 #include "lldb/Utility/Log.h"
@@ -133,9 +135,8 @@ FILE *File::GetStream() {
           m_should_close_fd = true;
         }
 
-        do {
-          m_stream = ::fdopen(m_descriptor, mode);
-        } while (m_stream == NULL && errno == EINTR);
+        m_stream =
+            llvm::sys::RetryAfterSignal(nullptr, ::fdopen, m_descriptor, mode);
 
         // If we got a stream, then we own the stream and should no
         // longer own the descriptor because fclose() will close it for us
@@ -157,6 +158,19 @@ void File::SetStream(FILE *fh, bool transfer_ownership) {
   m_own_stream = transfer_ownership;
 }
 
+static int DoOpen(const char *path, int flags, int mode) {
+#ifdef _MSC_VER
+  std::wstring wpath;
+  if (!llvm::ConvertUTF8toWide(path, wpath))
+    return -1;
+  int result;
+  ::_wsopen_s(&result, wpath.c_str(), flags, _SH_DENYNO, mode);
+  return result;
+#else
+  return ::open(path, flags, mode);
+#endif
+}
+
 Status File::Open(const char *path, uint32_t options, uint32_t permissions) {
   Status error;
   if (IsValid())
@@ -222,20 +236,7 @@ Status File::Open(const char *path, uint32_t options, uint32_t permissions) {
       mode |= S_IXOTH;
   }
 
-  do {
-#ifdef _MSC_VER
-    std::wstring wpath;
-    if (!llvm::ConvertUTF8toWide(path, wpath)) {
-      m_descriptor = -1;
-      error.SetErrorString("Error converting path to UTF-16");
-      return error;
-    }
-    ::_wsopen_s(&m_descriptor, wpath.c_str(), oflag, _SH_DENYNO, mode);
-#else
-    m_descriptor = ::open(path, oflag, mode);
-#endif
-  } while (m_descriptor < 0 && errno == EINTR);
-
+  m_descriptor = llvm::sys::RetryAfterSignal(-1, DoOpen, path, oflag, mode);
   if (!DescriptorIsValid())
     error.SetErrorToErrno();
   else {
@@ -421,12 +422,7 @@ off_t File::SeekFromEnd(off_t offset, Status *error_ptr) {
 Status File::Flush() {
   Status error;
   if (StreamIsValid()) {
-    int err = 0;
-    do {
-      err = ::fflush(m_stream);
-    } while (err == EOF && errno == EINTR);
-
-    if (err == EOF)
+    if (llvm::sys::RetryAfterSignal(EOF, ::fflush, m_stream) == EOF)
       error.SetErrorToErrno();
   } else if (!DescriptorIsValid()) {
     error.SetErrorString("invalid file handle");
@@ -442,12 +438,7 @@ Status File::Sync() {
     if (err == 0)
       error.SetErrorToGenericError();
 #else
-    int err = 0;
-    do {
-      err = ::fsync(m_descriptor);
-    } while (err == -1 && errno == EINTR);
-
-    if (err == -1)
+    if (llvm::sys::RetryAfterSignal(-1, ::fsync, m_descriptor) == -1)
       error.SetErrorToErrno();
 #endif
   } else {
@@ -497,10 +488,7 @@ Status File::Read(void *buf, size_t &num_bytes) {
 
   ssize_t bytes_read = -1;
   if (DescriptorIsValid()) {
-    do {
-      bytes_read = ::read(m_descriptor, buf, num_bytes);
-    } while (bytes_read < 0 && errno == EINTR);
-
+    bytes_read = llvm::sys::RetryAfterSignal(-1, ::read, m_descriptor, buf, num_bytes);
     if (bytes_read == -1) {
       error.SetErrorToErrno();
       num_bytes = 0;
@@ -559,10 +547,8 @@ Status File::Write(const void *buf, size_t &num_bytes) {
 
   ssize_t bytes_written = -1;
   if (DescriptorIsValid()) {
-    do {
-      bytes_written = ::write(m_descriptor, buf, num_bytes);
-    } while (bytes_written < 0 && errno == EINTR);
-
+    bytes_written =
+        llvm::sys::RetryAfterSignal(-1, ::write, m_descriptor, buf, num_bytes);
     if (bytes_written == -1) {
       error.SetErrorToErrno();
       num_bytes = 0;
@@ -624,11 +610,8 @@ Status File::Read(void *buf, size_t &num_bytes, off_t &offset) {
 #ifndef _WIN32
   int fd = GetDescriptor();
   if (fd != kInvalidDescriptor) {
-    ssize_t bytes_read = -1;
-    do {
-      bytes_read = ::pread(fd, buf, num_bytes, offset);
-    } while (bytes_read < 0 && errno == EINTR);
-
+    ssize_t bytes_read =
+        llvm::sys::RetryAfterSignal(-1, ::pread, fd, buf, num_bytes, offset);
     if (bytes_read < 0) {
       num_bytes = 0;
       error.SetErrorToErrno();
@@ -730,11 +713,8 @@ Status File::Write(const void *buf, size_t &num_bytes, off_t &offset) {
   int fd = GetDescriptor();
   if (fd != kInvalidDescriptor) {
 #ifndef _WIN32
-    ssize_t bytes_written = -1;
-    do {
-      bytes_written = ::pwrite(m_descriptor, buf, num_bytes, offset);
-    } while (bytes_written < 0 && errno == EINTR);
-
+    ssize_t bytes_written =
+        llvm::sys::RetryAfterSignal(-1, ::pwrite, m_descriptor, buf, num_bytes, offset);
     if (bytes_written < 0) {
       num_bytes = 0;
       error.SetErrorToErrno();
diff --git a/source/Host/common/MainLoop.cpp b/source/Host/common/MainLoop.cpp
index 7de6f7fa865d..c0c4471e735f 100644
--- a/source/Host/common/MainLoop.cpp
+++ b/source/Host/common/MainLoop.cpp
@@ -193,10 +193,16 @@ Status MainLoop::RunImpl::Poll() {
 
 void MainLoop::RunImpl::ProcessEvents() {
 #ifdef FORCE_PSELECT
-  for (const auto &fd : loop.m_read_fds) {
-    if (!FD_ISSET(fd.first, &read_fd_set))
-      continue;
-    IOObject::WaitableHandle handle = fd.first;
+  // Collect first all readable file descriptors into a separate vector and then
+  // iterate over it to invoke callbacks. Iterating directly over
+  // loop.m_read_fds is not possible because the callbacks can modify the
+  // container which could invalidate the iterator.
+  std::vector<IOObject::WaitableHandle> fds;
+  for (const auto &fd : loop.m_read_fds)
+    if (FD_ISSET(fd.first, &read_fd_set))
+      fds.push_back(fd.first);
+
+  for (const auto &handle : fds) {
 #else
   for (const auto &fd : read_fds) {
     if ((fd.revents & POLLIN) == 0)
@@ -209,13 +215,16 @@ void MainLoop::RunImpl::ProcessEvents() {
     loop.ProcessReadObject(handle);
   }
 
-  for (const auto &entry : loop.m_signals) {
+  std::vector<int> signals;
+  for (const auto &entry : loop.m_signals)
+    if (g_signal_flags[entry.first] != 0)
+      signals.push_back(entry.first);
+
+  for (const auto &signal : signals) {
     if (loop.m_terminate_request)
       return;
-    if (g_signal_flags[entry.first] == 0)
-      continue; // No signal
-    g_signal_flags[entry.first] = 0;
-    loop.ProcessSignal(entry.first);
+    g_signal_flags[signal] = 0;
+    loop.ProcessSignal(signal);
   }
 }
 #endif
diff --git a/source/Host/common/NativeProcessProtocol.cpp b/source/Host/common/NativeProcessProtocol.cpp
index 341c301dc9c5..b5b6e9d8b923 100644
--- a/source/Host/common/NativeProcessProtocol.cpp
+++ b/source/Host/common/NativeProcessProtocol.cpp
@@ -29,11 +29,13 @@ using namespace lldb_private;
 // NativeProcessProtocol Members
 // -----------------------------------------------------------------------------
 
-NativeProcessProtocol::NativeProcessProtocol(lldb::pid_t pid)
-    : m_pid(pid), m_threads(), m_current_thread_id(LLDB_INVALID_THREAD_ID),
-      m_threads_mutex(), m_state(lldb::eStateInvalid), m_state_mutex(),
-      m_delegates_mutex(), m_delegates(), m_breakpoint_list(),
-      m_watchpoint_list(), m_terminal_fd(-1), m_stop_id(0) {}
+NativeProcessProtocol::NativeProcessProtocol(lldb::pid_t pid, int terminal_fd,
+                                             NativeDelegate &delegate)
+    : m_pid(pid), m_terminal_fd(terminal_fd) {
+  bool registered = RegisterNativeDelegate(delegate);
+  assert(registered);
+  (void)registered;
+}
 
 lldb_private::Status NativeProcessProtocol::Interrupt() {
   Status error;
@@ -488,23 +490,4 @@ Status NativeProcessProtocol::ResolveProcessArchitecture(lldb::pid_t pid,
         "failed to retrieve a valid architecture from the exe module");
 }
 
-#if !defined(__linux__) && !defined(__NetBSD__)
-// These need to be implemented to support lldb-gdb-server on a given platform.
-// Stubs are
-// provided to make the rest of the code link on non-supported platforms.
-
-Status NativeProcessProtocol::Launch(ProcessLaunchInfo &launch_info,
-                                     NativeDelegate &native_delegate,
-                                     MainLoop &mainloop,
-                                     NativeProcessProtocolSP &process_sp) {
-  llvm_unreachable("Platform has no NativeProcessProtocol support");
-}
-
-Status NativeProcessProtocol::Attach(lldb::pid_t pid,
-                                     NativeDelegate &native_delegate,
-                                     MainLoop &mainloop,
-                                     NativeProcessProtocolSP &process_sp) {
-  llvm_unreachable("Platform has no NativeProcessProtocol support");
-}
-
-#endif
+NativeProcessProtocol::Factory::~Factory() = default;
diff --git a/source/Host/common/SocketAddress.cpp b/source/Host/common/SocketAddress.cpp
index 440ae5d9027f..41150fa7fd74 100644
--- a/source/Host/common/SocketAddress.cpp
+++ b/source/Host/common/SocketAddress.cpp
@@ -201,7 +201,7 @@ const SocketAddress &SocketAddress::
 operator=(const struct addrinfo *addr_info) {
   Clear();
   if (addr_info && addr_info->ai_addr && addr_info->ai_addrlen > 0 &&
-      addr_info->ai_addrlen <= sizeof m_socket_addr) {
+      size_t(addr_info->ai_addrlen) <= sizeof m_socket_addr) {
     ::memcpy(&m_socket_addr, addr_info->ai_addr, addr_info->ai_addrlen);
   }
   return *this;
diff --git a/source/Host/macosx/Host.mm b/source/Host/macosx/Host.mm
index bbf70cd4c4b3..75624ef21f43 100644
--- a/source/Host/macosx/Host.mm
+++ b/source/Host/macosx/Host.mm
@@ -74,6 +74,7 @@
 #include "lldb/Utility/StructuredData.h"
 
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Errno.h"
 
 #include "cfcpp/CFCBundle.h"
 #include "cfcpp/CFCMutableArray.h"
@@ -1663,10 +1664,7 @@ HostThread Host::StartMonitoringChildProcess(
       int wait_pid = 0;
       bool cancel = false;
       bool exited = false;
-      do {
-        wait_pid = ::waitpid(pid, &status, 0);
-      } while (wait_pid < 0 && errno == EINTR);
-
+      wait_pid = llvm::sys::RetryAfterSignal(-1, ::waitpid, pid, &status, 0);
       if (wait_pid >= 0) {
         int signal = 0;
         int exit_status = 0;
diff --git a/source/Host/posix/ConnectionFileDescriptorPosix.cpp b/source/Host/posix/ConnectionFileDescriptorPosix.cpp
index 6b0f069c35a9..105ef0f23d46 100644
--- a/source/Host/posix/ConnectionFileDescriptorPosix.cpp
+++ b/source/Host/posix/ConnectionFileDescriptorPosix.cpp
@@ -245,11 +245,7 @@ ConnectionStatus ConnectionFileDescriptor::Connect(llvm::StringRef path,
     } else if ((addr = GetURLAddress(path, FILE_SCHEME))) {
       std::string addr_str = addr->str();
       // file:///PATH
-      int fd = -1;
-      do {
-        fd = ::open(addr_str.c_str(), O_RDWR);
-      } while (fd == -1 && errno == EINTR);
-
+      int fd = llvm::sys::RetryAfterSignal(-1, ::open, addr_str.c_str(), O_RDWR);
       if (fd == -1) {
         if (error_ptr)
           error_ptr->SetErrorToErrno();
@@ -620,20 +616,17 @@ ConnectionFileDescriptor::BytesAvailable(const Timeout<std::micro> &timeout,
         if (select_helper.FDIsSetRead(pipe_fd)) {
           // There is an interrupt or exit command in the command pipe
           // Read the data from that pipe:
-          char buffer[1];
-
-          ssize_t bytes_read;
-
-          do {
-            bytes_read = ::read(pipe_fd, buffer, sizeof(buffer));
-          } while (bytes_read < 0 && errno == EINTR);
+          char c;
 
-          switch (buffer[0]) {
+          ssize_t bytes_read = llvm::sys::RetryAfterSignal(-1, ::read, pipe_fd, &c, 1);
+          assert(bytes_read == 1);
+          (void)bytes_read;
+          switch (c) {
           case 'q':
             if (log)
               log->Printf("%p ConnectionFileDescriptor::BytesAvailable() "
                           "got data: %c from the command channel.",
-                          static_cast<void *>(this), buffer[0]);
+                          static_cast<void *>(this), c);
             return eConnectionStatusEndOfFile;
           case 'i':
             // Interrupt the current read
diff --git a/source/Plugins/DynamicLoader/POSIX-DYLD/AuxVector.cpp b/source/Plugins/DynamicLoader/POSIX-DYLD/AuxVector.cpp
index d385b78e0ec4..5dbb3bb4ef7e 100644
--- a/source/Plugins/DynamicLoader/POSIX-DYLD/AuxVector.cpp
+++ b/source/Plugins/DynamicLoader/POSIX-DYLD/AuxVector.cpp
@@ -63,10 +63,10 @@ void AuxVector::ParseAuxv(DataExtractor &data) {
     if (!ParseAuxvEntry(data, entry, &offset, byte_size))
       break;
 
-    if (entry.type == AT_NULL)
+    if (entry.type == AUXV_AT_NULL)
       break;
 
-    if (entry.type == AT_IGNORE)
+    if (entry.type == AUXV_AT_IGNORE)
       continue;
 
     m_auxv.push_back(entry);
@@ -110,43 +110,43 @@ void AuxVector::DumpToLog(Log *log) const {
 const char *AuxVector::GetEntryName(EntryType type) {
   const char *name = "AT_???";
 
-#define ENTRY_NAME(_type)                                                      \
-  _type:                                                                       \
-  name = #_type
+#define ENTRY_NAME(_type) \
+  _type:                  \
+  name = #_type + 5
   switch (type) {
-    case ENTRY_NAME(AT_NULL);           break;
-    case ENTRY_NAME(AT_IGNORE);         break;
-    case ENTRY_NAME(AT_EXECFD);         break;
-    case ENTRY_NAME(AT_PHDR);           break;
-    case ENTRY_NAME(AT_PHENT);          break;
-    case ENTRY_NAME(AT_PHNUM);          break;
-    case ENTRY_NAME(AT_PAGESZ);         break;
-    case ENTRY_NAME(AT_BASE);           break;
-    case ENTRY_NAME(AT_FLAGS);          break;
-    case ENTRY_NAME(AT_ENTRY);          break;
-    case ENTRY_NAME(AT_NOTELF);         break;
-    case ENTRY_NAME(AT_UID);            break;
-    case ENTRY_NAME(AT_EUID);           break;
-    case ENTRY_NAME(AT_GID);            break;
-    case ENTRY_NAME(AT_EGID);           break;
-    case ENTRY_NAME(AT_CLKTCK);         break;
-    case ENTRY_NAME(AT_PLATFORM);       break;
-    case ENTRY_NAME(AT_HWCAP);          break;
-    case ENTRY_NAME(AT_FPUCW);          break;
-    case ENTRY_NAME(AT_DCACHEBSIZE);    break;
-    case ENTRY_NAME(AT_ICACHEBSIZE);    break;
-    case ENTRY_NAME(AT_UCACHEBSIZE);    break;
-    case ENTRY_NAME(AT_IGNOREPPC);      break;
-    case ENTRY_NAME(AT_SECURE);         break;
-    case ENTRY_NAME(AT_BASE_PLATFORM);  break;
-    case ENTRY_NAME(AT_RANDOM);         break;
-    case ENTRY_NAME(AT_EXECFN);         break;
-    case ENTRY_NAME(AT_SYSINFO);        break;
-    case ENTRY_NAME(AT_SYSINFO_EHDR);   break;
-    case ENTRY_NAME(AT_L1I_CACHESHAPE); break;
-    case ENTRY_NAME(AT_L1D_CACHESHAPE); break;
-    case ENTRY_NAME(AT_L2_CACHESHAPE);  break;
-    case ENTRY_NAME(AT_L3_CACHESHAPE);  break;
+    case ENTRY_NAME(AUXV_AT_NULL);           break;
+    case ENTRY_NAME(AUXV_AT_IGNORE);         break;
+    case ENTRY_NAME(AUXV_AT_EXECFD);         break;
+    case ENTRY_NAME(AUXV_AT_PHDR);           break;
+    case ENTRY_NAME(AUXV_AT_PHENT);          break;
+    case ENTRY_NAME(AUXV_AT_PHNUM);          break;
+    case ENTRY_NAME(AUXV_AT_PAGESZ);         break;
+    case ENTRY_NAME(AUXV_AT_BASE);           break;
+    case ENTRY_NAME(AUXV_AT_FLAGS);          break;
+    case ENTRY_NAME(AUXV_AT_ENTRY);          break;
+    case ENTRY_NAME(AUXV_AT_NOTELF);         break;
+    case ENTRY_NAME(AUXV_AT_UID);            break;
+    case ENTRY_NAME(AUXV_AT_EUID);           break;
+    case ENTRY_NAME(AUXV_AT_GID);            break;
+    case ENTRY_NAME(AUXV_AT_EGID);           break;
+    case ENTRY_NAME(AUXV_AT_CLKTCK);         break;
+    case ENTRY_NAME(AUXV_AT_PLATFORM);       break;
+    case ENTRY_NAME(AUXV_AT_HWCAP);          break;
+    case ENTRY_NAME(AUXV_AT_FPUCW);          break;
+    case ENTRY_NAME(AUXV_AT_DCACHEBSIZE);    break;
+    case ENTRY_NAME(AUXV_AT_ICACHEBSIZE);    break;
+    case ENTRY_NAME(AUXV_AT_UCACHEBSIZE);    break;
+    case ENTRY_NAME(AUXV_AT_IGNOREPPC);      break;
+    case ENTRY_NAME(AUXV_AT_SECURE);         break;
+    case ENTRY_NAME(AUXV_AT_BASE_PLATFORM);  break;
+    case ENTRY_NAME(AUXV_AT_RANDOM);         break;
+    case ENTRY_NAME(AUXV_AT_EXECFN);         break;
+    case ENTRY_NAME(AUXV_AT_SYSINFO);        break;
+    case ENTRY_NAME(AUXV_AT_SYSINFO_EHDR);   break;
+    case ENTRY_NAME(AUXV_AT_L1I_CACHESHAPE); break;
+    case ENTRY_NAME(AUXV_AT_L1D_CACHESHAPE); break;
+    case ENTRY_NAME(AUXV_AT_L2_CACHESHAPE);  break;
+    case ENTRY_NAME(AUXV_AT_L3_CACHESHAPE);  break;
     }
 #undef ENTRY_NAME
 
diff --git a/source/Plugins/DynamicLoader/POSIX-DYLD/AuxVector.h b/source/Plugins/DynamicLoader/POSIX-DYLD/AuxVector.h
index 9c3e1b002a24..cf9da0808357 100644
--- a/source/Plugins/DynamicLoader/POSIX-DYLD/AuxVector.h
+++ b/source/Plugins/DynamicLoader/POSIX-DYLD/AuxVector.h
@@ -42,41 +42,42 @@ public:
 
   /// Constants describing the type of entry.
   /// On Linux, running "LD_SHOW_AUXV=1 ./executable" will spew AUX information.
+  /// Added AUXV prefix to avoid potential conflicts with system-defined macros
   enum EntryType {
-    AT_NULL = 0,      ///< End of auxv.
-    AT_IGNORE = 1,    ///< Ignore entry.
-    AT_EXECFD = 2,    ///< File descriptor of program.
-    AT_PHDR = 3,      ///< Program headers.
-    AT_PHENT = 4,     ///< Size of program header.
-    AT_PHNUM = 5,     ///< Number of program headers.
-    AT_PAGESZ = 6,    ///< Page size.
-    AT_BASE = 7,      ///< Interpreter base address.
-    AT_FLAGS = 8,     ///< Flags.
-    AT_ENTRY = 9,     ///< Program entry point.
-    AT_NOTELF = 10,   ///< Set if program is not an ELF.
-    AT_UID = 11,      ///< UID.
-    AT_EUID = 12,     ///< Effective UID.
-    AT_GID = 13,      ///< GID.
-    AT_EGID = 14,     ///< Effective GID.
-    AT_CLKTCK = 17,   ///< Clock frequency (e.g. times(2)).
-    AT_PLATFORM = 15, ///< String identifying platform.
-    AT_HWCAP = 16,    ///< Machine dependent hints about processor capabilities.
-    AT_FPUCW = 18,    ///< Used FPU control word.
-    AT_DCACHEBSIZE = 19,   ///< Data cache block size.
-    AT_ICACHEBSIZE = 20,   ///< Instruction cache block size.
-    AT_UCACHEBSIZE = 21,   ///< Unified cache block size.
-    AT_IGNOREPPC = 22,     ///< Entry should be ignored.
-    AT_SECURE = 23,        ///< Boolean, was exec setuid-like?
-    AT_BASE_PLATFORM = 24, ///< String identifying real platforms.
-    AT_RANDOM = 25,        ///< Address of 16 random bytes.
-    AT_EXECFN = 31,        ///< Filename of executable.
-    AT_SYSINFO = 32, ///< Pointer to the global system page used for system
-                     ///calls and other nice things.
-    AT_SYSINFO_EHDR = 33,
-    AT_L1I_CACHESHAPE = 34, ///< Shapes of the caches.
-    AT_L1D_CACHESHAPE = 35,
-    AT_L2_CACHESHAPE = 36,
-    AT_L3_CACHESHAPE = 37,
+    AUXV_AT_NULL = 0,            ///< End of auxv.
+    AUXV_AT_IGNORE = 1,          ///< Ignore entry.
+    AUXV_AT_EXECFD = 2,          ///< File descriptor of program.
+    AUXV_AT_PHDR = 3,            ///< Program headers.
+    AUXV_AT_PHENT = 4,           ///< Size of program header.
+    AUXV_AT_PHNUM = 5,           ///< Number of program headers.
+    AUXV_AT_PAGESZ = 6,          ///< Page size.
+    AUXV_AT_BASE = 7,            ///< Interpreter base address.
+    AUXV_AT_FLAGS = 8,           ///< Flags.
+    AUXV_AT_ENTRY = 9,           ///< Program entry point.
+    AUXV_AT_NOTELF = 10,         ///< Set if program is not an ELF.
+    AUXV_AT_UID = 11,            ///< UID.
+    AUXV_AT_EUID = 12,           ///< Effective UID.
+    AUXV_AT_GID = 13,            ///< GID.
+    AUXV_AT_EGID = 14,           ///< Effective GID.
+    AUXV_AT_CLKTCK = 17,         ///< Clock frequency (e.g. times(2)).
+    AUXV_AT_PLATFORM = 15,       ///< String identifying platform.
+    AUXV_AT_HWCAP = 16,          ///< Machine dependent hints about processor capabilities.
+    AUXV_AT_FPUCW = 18,          ///< Used FPU control word.
+    AUXV_AT_DCACHEBSIZE = 19,    ///< Data cache block size.
+    AUXV_AT_ICACHEBSIZE = 20,    ///< Instruction cache block size.
+    AUXV_AT_UCACHEBSIZE = 21,    ///< Unified cache block size.
+    AUXV_AT_IGNOREPPC = 22,      ///< Entry should be ignored.
+    AUXV_AT_SECURE = 23,         ///< Boolean, was exec setuid-like?
+    AUXV_AT_BASE_PLATFORM = 24,  ///< String identifying real platforms.
+    AUXV_AT_RANDOM = 25,         ///< Address of 16 random bytes.
+    AUXV_AT_EXECFN = 31,         ///< Filename of executable.
+    AUXV_AT_SYSINFO = 32,        ///< Pointer to the global system page used for system
+                                 ///calls and other nice things.
+    AUXV_AT_SYSINFO_EHDR = 33,
+    AUXV_AT_L1I_CACHESHAPE = 34, ///< Shapes of the caches.
+    AUXV_AT_L1D_CACHESHAPE = 35,
+    AUXV_AT_L2_CACHESHAPE = 36,
+    AUXV_AT_L3_CACHESHAPE = 37,
   };
 
 private:
diff --git a/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp b/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp
index 0092535648bd..a7afeb6d68c3 100644
--- a/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp
+++ b/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp
@@ -576,7 +576,7 @@ addr_t DynamicLoaderPOSIXDYLD::ComputeLoadOffset() {
 }
 
 void DynamicLoaderPOSIXDYLD::EvalVdsoStatus() {
-  AuxVector::iterator I = m_auxv->FindEntry(AuxVector::AT_SYSINFO_EHDR);
+  AuxVector::iterator I = m_auxv->FindEntry(AuxVector::AUXV_AT_SYSINFO_EHDR);
 
   if (I != m_auxv->end())
     m_vdso_base = I->value;
@@ -589,7 +589,7 @@ addr_t DynamicLoaderPOSIXDYLD::GetEntryPoint() {
   if (m_auxv.get() == NULL)
     return LLDB_INVALID_ADDRESS;
 
-  AuxVector::iterator I = m_auxv->FindEntry(AuxVector::AT_ENTRY);
+  AuxVector::iterator I = m_auxv->FindEntry(AuxVector::AUXV_AT_ENTRY);
 
   if (I == m_auxv->end())
     return LLDB_INVALID_ADDRESS;
diff --git a/source/Plugins/InstrumentationRuntime/ASan/ASanRuntime.cpp b/source/Plugins/InstrumentationRuntime/ASan/ASanRuntime.cpp
index af242d786a5f..9a6e39be0bfd 100644
--- a/source/Plugins/InstrumentationRuntime/ASan/ASanRuntime.cpp
+++ b/source/Plugins/InstrumentationRuntime/ASan/ASanRuntime.cpp
@@ -247,12 +247,16 @@ bool AddressSanitizerRuntime::NotifyBreakpointHit(
   AddressSanitizerRuntime *const instance =
       static_cast<AddressSanitizerRuntime *>(baton);
 
+  ProcessSP process_sp = instance->GetProcessSP();
+
+  if (process_sp->GetModIDRef().IsLastResumeForUserExpression())
+    return false;
+
   StructuredData::ObjectSP report = instance->RetrieveReportData();
   std::string description;
   if (report) {
     description = instance->FormatDescription(report);
   }
-  ProcessSP process_sp = instance->GetProcessSP();
   // Make sure this is the right process
   if (process_sp && process_sp == context->exe_ctx_ref.GetProcessSP()) {
     ThreadSP thread_sp = context->exe_ctx_ref.GetThreadSP();
diff --git a/source/Plugins/InstrumentationRuntime/MainThreadChecker/MainThreadCheckerRuntime.cpp b/source/Plugins/InstrumentationRuntime/MainThreadChecker/MainThreadCheckerRuntime.cpp
index 3c22b81df7a4..eb238419ab18 100644
--- a/source/Plugins/InstrumentationRuntime/MainThreadChecker/MainThreadCheckerRuntime.cpp
+++ b/source/Plugins/InstrumentationRuntime/MainThreadChecker/MainThreadCheckerRuntime.cpp
@@ -141,7 +141,7 @@ MainThreadCheckerRuntime::RetrieveReportData(ExecutionContextRef exe_ctx_ref) {
   d->AddStringItem("class_name", className);
   d->AddStringItem("selector", selector);
   d->AddStringItem("description",
-                   apiName + " must be called from main thread only");
+                   apiName + " must be used from main thread only");
   d->AddIntegerItem("tid", thread_sp->GetIndexID());
   d->AddItem("trace", trace_sp);
   return dict_sp;
@@ -163,6 +163,9 @@ bool MainThreadCheckerRuntime::NotifyBreakpointHit(
       process_sp != context->exe_ctx_ref.GetProcessSP())
     return false;
 
+  if (process_sp->GetModIDRef().IsLastResumeForUserExpression())
+    return false;
+
   StructuredData::ObjectSP report =
       instance->RetrieveReportData(context->exe_ctx_ref);
 
diff --git a/source/Plugins/InstrumentationRuntime/TSan/TSanRuntime.cpp b/source/Plugins/InstrumentationRuntime/TSan/TSanRuntime.cpp
index f60df0463346..cf9ba60c7b60 100644
--- a/source/Plugins/InstrumentationRuntime/TSan/TSanRuntime.cpp
+++ b/source/Plugins/InstrumentationRuntime/TSan/TSanRuntime.cpp
@@ -803,6 +803,11 @@ bool ThreadSanitizerRuntime::NotifyBreakpointHit(
   ThreadSanitizerRuntime *const instance =
       static_cast<ThreadSanitizerRuntime *>(baton);
 
+  ProcessSP process_sp = instance->GetProcessSP();
+
+  if (process_sp->GetModIDRef().IsLastResumeForUserExpression())
+    return false;
+
   StructuredData::ObjectSP report =
       instance->RetrieveReportData(context->exe_ctx_ref);
   std::string stop_reason_description;
@@ -851,7 +856,6 @@ bool ThreadSanitizerRuntime::NotifyBreakpointHit(
                                               all_addresses_are_same);
   }
 
-  ProcessSP process_sp = instance->GetProcessSP();
   // Make sure this is the right process
   if (process_sp && process_sp == context->exe_ctx_ref.GetProcessSP()) {
     ThreadSP thread_sp = context->exe_ctx_ref.GetThreadSP();
diff --git a/source/Plugins/InstrumentationRuntime/UBSan/UBSanRuntime.cpp b/source/Plugins/InstrumentationRuntime/UBSan/UBSanRuntime.cpp
index 023af84179aa..28c28e41ef44 100644
--- a/source/Plugins/InstrumentationRuntime/UBSan/UBSanRuntime.cpp
+++ b/source/Plugins/InstrumentationRuntime/UBSan/UBSanRuntime.cpp
@@ -217,6 +217,9 @@ bool UndefinedBehaviorSanitizerRuntime::NotifyBreakpointHit(
       process_sp != context->exe_ctx_ref.GetProcessSP())
     return false;
 
+  if (process_sp->GetModIDRef().IsLastResumeForUserExpression())
+    return false;
+
   StructuredData::ObjectSP report =
       instance->RetrieveReportData(context->exe_ctx_ref);
 
diff --git a/source/Plugins/Language/ObjC/Cocoa.cpp b/source/Plugins/Language/ObjC/Cocoa.cpp
index 2ba005e02ad4..8f4997533212 100644
--- a/source/Plugins/Language/ObjC/Cocoa.cpp
+++ b/source/Plugins/Language/ObjC/Cocoa.cpp
@@ -543,6 +543,7 @@ bool lldb_private::formatters::NSNumberSummaryProvider(
       }
       
       uint64_t value = 0;
+      bool success = false;
       switch (type_code) {
         case TypeCodes::sint8:
         value = process_sp->ReadUnsignedIntegerFromMemory(data_location, 1, 0,
@@ -550,6 +551,7 @@ bool lldb_private::formatters::NSNumberSummaryProvider(
         if (error.Fail())
           return false;
         NSNumber_FormatChar(valobj, stream, (char)value, options.GetLanguage());
+        success = true;
         break;
         case TypeCodes::sint16:
         value = process_sp->ReadUnsignedIntegerFromMemory(data_location, 2, 0,
@@ -558,6 +560,7 @@ bool lldb_private::formatters::NSNumberSummaryProvider(
           return false;
         NSNumber_FormatShort(valobj, stream, (short)value,
                              options.GetLanguage());
+        success = true;
         break;
       case TypeCodes::sint32:
         value = process_sp->ReadUnsignedIntegerFromMemory(data_location, 4, 0,
@@ -565,6 +568,7 @@ bool lldb_private::formatters::NSNumberSummaryProvider(
         if (error.Fail())
           return false;
         NSNumber_FormatInt(valobj, stream, (int)value, options.GetLanguage());
+        success = true;
         break;
       case TypeCodes::sint64:
         value = process_sp->ReadUnsignedIntegerFromMemory(data_location, 8, 0,
@@ -572,6 +576,7 @@ bool lldb_private::formatters::NSNumberSummaryProvider(
         if (error.Fail())
           return false;
         NSNumber_FormatLong(valobj, stream, value, options.GetLanguage());
+        success = true;
         break;
       case TypeCodes::f32:
       {
@@ -582,6 +587,7 @@ bool lldb_private::formatters::NSNumberSummaryProvider(
         float flt_value = 0.0f;
         memcpy(&flt_value, &flt_as_int, sizeof(flt_as_int));
         NSNumber_FormatFloat(valobj, stream, flt_value, options.GetLanguage());
+        success = true;
         break;
       }
       case TypeCodes::f64:
@@ -593,6 +599,7 @@ bool lldb_private::formatters::NSNumberSummaryProvider(
         double dbl_value = 0.0;
         memcpy(&dbl_value, &dbl_as_lng, sizeof(dbl_as_lng));
         NSNumber_FormatDouble(valobj, stream, dbl_value, options.GetLanguage());
+        success = true;
         break;
       }
       case TypeCodes::sint128: // internally, this is the same
@@ -608,12 +615,11 @@ bool lldb_private::formatters::NSNumberSummaryProvider(
           return false;
         llvm::APInt i128_value(128, words);
         NSNumber_FormatInt128(valobj, stream, i128_value, options.GetLanguage());
+        success = true;
         break;
       }
-      default:
-        return false;
       }
-      return true;
+      return success;
     }
   }
 
diff --git a/source/Plugins/Platform/Android/PlatformAndroid.cpp b/source/Plugins/Platform/Android/PlatformAndroid.cpp
index d896a9f99e63..0f37da60d5d6 100644
--- a/source/Plugins/Platform/Android/PlatformAndroid.cpp
+++ b/source/Plugins/Platform/Android/PlatformAndroid.cpp
@@ -366,13 +366,17 @@ bool PlatformAndroid::GetRemoteOSVersion() {
   return m_major_os_version != 0;
 }
 
-const char *PlatformAndroid::GetLibdlFunctionDeclarations() const {
-  return R"(
+llvm::StringRef PlatformAndroid::GetLibdlFunctionDeclarations() {
+  // Older platform versions have the dl function symbols mangled
+  if (GetSdkVersion() < 26)
+    return R"(
               extern "C" void* dlopen(const char*, int) asm("__dl_dlopen");
               extern "C" void* dlsym(void*, const char*) asm("__dl_dlsym");
               extern "C" int   dlclose(void*) asm("__dl_dlclose");
               extern "C" char* dlerror(void) asm("__dl_dlerror");
              )";
+
+  return PlatformPOSIX::GetLibdlFunctionDeclarations();
 }
 
 AdbClient::SyncService *PlatformAndroid::GetSyncService(Status &error) {
diff --git a/source/Plugins/Platform/Android/PlatformAndroid.h b/source/Plugins/Platform/Android/PlatformAndroid.h
index 8fb4cc71a69f..638dba973369 100644
--- a/source/Plugins/Platform/Android/PlatformAndroid.h
+++ b/source/Plugins/Platform/Android/PlatformAndroid.h
@@ -76,7 +76,7 @@ protected:
   Status DownloadSymbolFile(const lldb::ModuleSP &module_sp,
                             const FileSpec &dst_file_spec) override;
 
-  const char *GetLibdlFunctionDeclarations() const override;
+  llvm::StringRef GetLibdlFunctionDeclarations() override;
 
 private:
   AdbClient::SyncService *GetSyncService(Status &error);
diff --git a/source/Plugins/Platform/POSIX/PlatformPOSIX.cpp b/source/Plugins/Platform/POSIX/PlatformPOSIX.cpp
index f4cf22ad7583..013c33def13b 100644
--- a/source/Plugins/Platform/POSIX/PlatformPOSIX.cpp
+++ b/source/Plugins/Platform/POSIX/PlatformPOSIX.cpp
@@ -884,7 +884,7 @@ void PlatformPOSIX::CalculateTrapHandlerSymbolNames() {
 
 Status PlatformPOSIX::EvaluateLibdlExpression(
     lldb_private::Process *process, const char *expr_cstr,
-    const char *expr_prefix, lldb::ValueObjectSP &result_valobj_sp) {
+    llvm::StringRef expr_prefix, lldb::ValueObjectSP &result_valobj_sp) {
   DynamicLoader *loader = process->GetDynamicLoader();
   if (loader) {
     Status error = loader->CanLoadImage();
@@ -944,7 +944,7 @@ uint32_t PlatformPOSIX::DoLoadImage(lldb_private::Process *process,
                    the_result;
                   )",
               path);
-  const char *prefix = GetLibdlFunctionDeclarations();
+  llvm::StringRef prefix = GetLibdlFunctionDeclarations();
   lldb::ValueObjectSP result_valobj_sp;
   error = EvaluateLibdlExpression(process, expr.GetData(), prefix,
                                   result_valobj_sp);
@@ -992,7 +992,7 @@ Status PlatformPOSIX::UnloadImage(lldb_private::Process *process,
 
   StreamString expr;
   expr.Printf("dlclose((void *)0x%" PRIx64 ")", image_addr);
-  const char *prefix = GetLibdlFunctionDeclarations();
+  llvm::StringRef prefix = GetLibdlFunctionDeclarations();
   lldb::ValueObjectSP result_valobj_sp;
   Status error = EvaluateLibdlExpression(process, expr.GetData(), prefix,
                                          result_valobj_sp);
@@ -1024,7 +1024,7 @@ lldb::ProcessSP PlatformPOSIX::ConnectProcess(llvm::StringRef connect_url,
                                   error);
 }
 
-const char *PlatformPOSIX::GetLibdlFunctionDeclarations() const {
+llvm::StringRef PlatformPOSIX::GetLibdlFunctionDeclarations() {
   return R"(
               extern "C" void* dlopen(const char*, int);
               extern "C" void* dlsym(void*, const char*);
diff --git a/source/Plugins/Platform/POSIX/PlatformPOSIX.h b/source/Plugins/Platform/POSIX/PlatformPOSIX.h
index 742702b07b88..ebc36c2461db 100644
--- a/source/Plugins/Platform/POSIX/PlatformPOSIX.h
+++ b/source/Plugins/Platform/POSIX/PlatformPOSIX.h
@@ -198,10 +198,10 @@ protected:
 
   lldb_private::Status
   EvaluateLibdlExpression(lldb_private::Process *process, const char *expr_cstr,
-                          const char *expr_prefix,
+                          llvm::StringRef expr_prefix,
                           lldb::ValueObjectSP &result_valobj_sp);
 
-  virtual const char *GetLibdlFunctionDeclarations() const;
+  virtual llvm::StringRef GetLibdlFunctionDeclarations();
 
 private:
   DISALLOW_COPY_AND_ASSIGN(PlatformPOSIX);
diff --git a/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp b/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp
index 10dd14753914..a4f5f02dde62 100644
--- a/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp
+++ b/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp
@@ -746,15 +746,9 @@ ProcessMonitor::ProcessMonitor(
   if (!error.Success())
     return;
 
-WAIT_AGAIN:
-  // Wait for the operation thread to initialize.
-  if (sem_wait(&args->m_semaphore)) {
-    if (errno == EINTR)
-      goto WAIT_AGAIN;
-    else {
-      error.SetErrorToErrno();
-      return;
-    }
+  if (llvm::sys::RetryAfterSignal(-1, sem_wait, &args->m_semaphore) == -1) {
+    error.SetErrorToErrno();
+    return;
   }
 
   // Check that the launch was a success.
@@ -790,15 +784,9 @@ ProcessMonitor::ProcessMonitor(ProcessFreeBSD *process, lldb::pid_t pid,
   if (!error.Success())
     return;
 
-WAIT_AGAIN:
-  // Wait for the operation thread to initialize.
-  if (sem_wait(&args->m_semaphore)) {
-    if (errno == EINTR)
-      goto WAIT_AGAIN;
-    else {
-      error.SetErrorToErrno();
-      return;
-    }
+  if (llvm::sys::RetryAfterSignal(-1, sem_wait, &args->m_semaphore) == -1) {
+    error.SetErrorToErrno();
+    return;
   }
 
   // Check that the attach was a success.
diff --git a/source/Plugins/Process/Linux/NativeProcessLinux.cpp b/source/Plugins/Process/Linux/NativeProcessLinux.cpp
index 8e378802de9c..d988ee93a2bc 100644
--- a/source/Plugins/Process/Linux/NativeProcessLinux.cpp
+++ b/source/Plugins/Process/Linux/NativeProcessLinux.cpp
@@ -214,207 +214,122 @@ static Status EnsureFDFlags(int fd, int flags) {
 // Public Static Methods
 // -----------------------------------------------------------------------------
 
-Status NativeProcessProtocol::Launch(
-    ProcessLaunchInfo &launch_info,
-    NativeProcessProtocol::NativeDelegate &native_delegate, MainLoop &mainloop,
-    NativeProcessProtocolSP &native_process_sp) {
+llvm::Expected<NativeProcessProtocolSP>
+NativeProcessLinux::Factory::Launch(ProcessLaunchInfo &launch_info,
+                                    NativeDelegate &native_delegate,
+                                    MainLoop &mainloop) const {
   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
 
-  Status error;
+  MaybeLogLaunchInfo(launch_info);
 
-  // Verify the working directory is valid if one was specified.
-  FileSpec working_dir{launch_info.GetWorkingDirectory()};
-  if (working_dir && (!working_dir.ResolvePath() ||
-                      !llvm::sys::fs::is_directory(working_dir.GetPath()))) {
-    error.SetErrorStringWithFormat("No such file or directory: %s",
-                                   working_dir.GetCString());
-    return error;
+  Status status;
+  ::pid_t pid = ProcessLauncherPosixFork()
+                    .LaunchProcess(launch_info, status)
+                    .GetProcessId();
+  LLDB_LOG(log, "pid = {0:x}", pid);
+  if (status.Fail()) {
+    LLDB_LOG(log, "failed to launch process: {0}", status);
+    return status.ToError();
   }
 
-  // Create the NativeProcessLinux in launch mode.
-  native_process_sp.reset(new NativeProcessLinux());
-
-  if (!native_process_sp->RegisterNativeDelegate(native_delegate)) {
-    native_process_sp.reset();
-    error.SetErrorStringWithFormat("failed to register the native delegate");
-    return error;
+  // Wait for the child process to trap on its call to execve.
+  int wstatus;
+  ::pid_t wpid = llvm::sys::RetryAfterSignal(-1, ::waitpid, pid, &wstatus, 0);
+  assert(wpid == pid);
+  (void)wpid;
+  if (!WIFSTOPPED(wstatus)) {
+    LLDB_LOG(log, "Could not sync with inferior process: wstatus={1}",
+             WaitStatus::Decode(wstatus));
+    return llvm::make_error<StringError>("Could not sync with inferior process",
+                                         llvm::inconvertibleErrorCode());
   }
+  LLDB_LOG(log, "inferior started, now in stopped state");
 
-  error = std::static_pointer_cast<NativeProcessLinux>(native_process_sp)
-              ->LaunchInferior(mainloop, launch_info);
+  ArchSpec arch;
+  if ((status = ResolveProcessArchitecture(pid, arch)).Fail())
+    return status.ToError();
 
-  if (error.Fail()) {
-    native_process_sp.reset();
-    LLDB_LOG(log, "failed to launch process: {0}", error);
-    return error;
-  }
+  // Set the architecture to the exe architecture.
+  LLDB_LOG(log, "pid = {0:x}, detected architecture {1}", pid,
+           arch.GetArchitectureName());
 
-  launch_info.SetProcessID(native_process_sp->GetID());
+  status = SetDefaultPtraceOpts(pid);
+  if (status.Fail()) {
+    LLDB_LOG(log, "failed to set default ptrace options: {0}", status);
+    return status.ToError();
+  }
 
-  return error;
+  std::shared_ptr<NativeProcessLinux> process_sp(new NativeProcessLinux(
+      pid, launch_info.GetPTY().ReleaseMasterFileDescriptor(), native_delegate,
+      arch, mainloop));
+  process_sp->InitializeThreads({pid});
+  return process_sp;
 }
 
-Status NativeProcessProtocol::Attach(
+llvm::Expected<NativeProcessProtocolSP> NativeProcessLinux::Factory::Attach(
     lldb::pid_t pid, NativeProcessProtocol::NativeDelegate &native_delegate,
-    MainLoop &mainloop, NativeProcessProtocolSP &native_process_sp) {
+    MainLoop &mainloop) const {
   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
   LLDB_LOG(log, "pid = {0:x}", pid);
 
   // Retrieve the architecture for the running process.
-  ArchSpec process_arch;
-  Status error = ResolveProcessArchitecture(pid, process_arch);
-  if (!error.Success())
-    return error;
+  ArchSpec arch;
+  Status status = ResolveProcessArchitecture(pid, arch);
+  if (!status.Success())
+    return status.ToError();
 
-  std::shared_ptr<NativeProcessLinux> native_process_linux_sp(
-      new NativeProcessLinux());
+  auto tids_or = NativeProcessLinux::Attach(pid);
+  if (!tids_or)
+    return tids_or.takeError();
 
-  if (!native_process_linux_sp->RegisterNativeDelegate(native_delegate)) {
-    error.SetErrorStringWithFormat("failed to register the native delegate");
-    return error;
-  }
-
-  native_process_linux_sp->AttachToInferior(mainloop, pid, error);
-  if (!error.Success())
-    return error;
-
-  native_process_sp = native_process_linux_sp;
-  return error;
+  std::shared_ptr<NativeProcessLinux> process_sp(
+      new NativeProcessLinux(pid, -1, native_delegate, arch, mainloop));
+  process_sp->InitializeThreads(*tids_or);
+  return process_sp;
 }
 
 // -----------------------------------------------------------------------------
 // Public Instance Methods
 // -----------------------------------------------------------------------------
 
-NativeProcessLinux::NativeProcessLinux()
-    : NativeProcessProtocol(LLDB_INVALID_PROCESS_ID), m_arch(),
-      m_supports_mem_region(eLazyBoolCalculate), m_mem_region_cache(),
-      m_pending_notification_tid(LLDB_INVALID_THREAD_ID),
-      m_pt_proces_trace_id(LLDB_INVALID_UID) {}
-
-void NativeProcessLinux::AttachToInferior(MainLoop &mainloop, lldb::pid_t pid,
-                                          Status &error) {
-  Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
-  LLDB_LOG(log, "pid = {0:x}", pid);
+NativeProcessLinux::NativeProcessLinux(::pid_t pid, int terminal_fd,
+                                       NativeDelegate &delegate,
+                                       const ArchSpec &arch, MainLoop &mainloop)
+    : NativeProcessProtocol(pid, terminal_fd, delegate), m_arch(arch) {
+  if (m_terminal_fd != -1) {
+    Status status = EnsureFDFlags(m_terminal_fd, O_NONBLOCK);
+    assert(status.Success());
+  }
 
+  Status status;
   m_sigchld_handle = mainloop.RegisterSignal(
-      SIGCHLD, [this](MainLoopBase &) { SigchldHandler(); }, error);
-  if (!m_sigchld_handle)
-    return;
-
-  error = ResolveProcessArchitecture(pid, m_arch);
-  if (!error.Success())
-    return;
-
-  // Set the architecture to the exe architecture.
-  LLDB_LOG(log, "pid = {0:x}, detected architecture {1}", pid,
-           m_arch.GetArchitectureName());
-  m_pid = pid;
-  SetState(eStateAttaching);
-
-  Attach(pid, error);
+      SIGCHLD, [this](MainLoopBase &) { SigchldHandler(); }, status);
+  assert(m_sigchld_handle && status.Success());
 }
 
-Status NativeProcessLinux::LaunchInferior(MainLoop &mainloop,
-                                          ProcessLaunchInfo &launch_info) {
-  Status error;
-  m_sigchld_handle = mainloop.RegisterSignal(
-      SIGCHLD, [this](MainLoopBase &) { SigchldHandler(); }, error);
-  if (!m_sigchld_handle)
-    return error;
-
-  SetState(eStateLaunching);
-
-  MaybeLogLaunchInfo(launch_info);
-
-  ::pid_t pid =
-      ProcessLauncherPosixFork().LaunchProcess(launch_info, error).GetProcessId();
-  if (error.Fail())
-    return error;
-
-  Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
-
-  // Wait for the child process to trap on its call to execve.
-  ::pid_t wpid;
-  int status;
-  if ((wpid = waitpid(pid, &status, 0)) < 0) {
-    error.SetErrorToErrno();
-    LLDB_LOG(log, "waitpid for inferior failed with %s", error);
-
-    // Mark the inferior as invalid.
-    // FIXME this could really use a new state - eStateLaunchFailure.  For now,
-    // using eStateInvalid.
-    SetState(StateType::eStateInvalid);
-
-    return error;
-  }
-  assert(WIFSTOPPED(status) && (wpid == static_cast<::pid_t>(pid)) &&
-         "Could not sync with inferior process.");
-
-  LLDB_LOG(log, "inferior started, now in stopped state");
-  error = SetDefaultPtraceOpts(pid);
-  if (error.Fail()) {
-    LLDB_LOG(log, "failed to set default ptrace options: {0}", error);
-
-    // Mark the inferior as invalid.
-    // FIXME this could really use a new state - eStateLaunchFailure.  For now,
-    // using eStateInvalid.
-    SetState(StateType::eStateInvalid);
-
-    return error;
-  }
-
-  // Release the master terminal descriptor and pass it off to the
-  // NativeProcessLinux instance.  Similarly stash the inferior pid.
-  m_terminal_fd = launch_info.GetPTY().ReleaseMasterFileDescriptor();
-  m_pid = pid;
-  launch_info.SetProcessID(pid);
-
-  if (m_terminal_fd != -1) {
-    error = EnsureFDFlags(m_terminal_fd, O_NONBLOCK);
-    if (error.Fail()) {
-      LLDB_LOG(log,
-               "inferior EnsureFDFlags failed for ensuring terminal "
-               "O_NONBLOCK setting: {0}",
-               error);
-
-      // Mark the inferior as invalid.
-      // FIXME this could really use a new state - eStateLaunchFailure.  For
-      // now, using eStateInvalid.
-      SetState(StateType::eStateInvalid);
-
-      return error;
-    }
+void NativeProcessLinux::InitializeThreads(llvm::ArrayRef<::pid_t> tids) {
+  for (const auto &tid : tids) {
+    NativeThreadLinuxSP thread_sp = AddThread(tid);
+    assert(thread_sp && "AddThread() returned a nullptr thread");
+    thread_sp->SetStoppedBySignal(SIGSTOP);
+    ThreadWasCreated(*thread_sp);
   }
 
-  LLDB_LOG(log, "adding pid = {0}", pid);
-  ResolveProcessArchitecture(m_pid, m_arch);
-  NativeThreadLinuxSP thread_sp = AddThread(pid);
-  assert(thread_sp && "AddThread() returned a nullptr thread");
-  thread_sp->SetStoppedBySignal(SIGSTOP);
-  ThreadWasCreated(*thread_sp);
-
   // Let our process instance know the thread has stopped.
-  SetCurrentThreadID(thread_sp->GetID());
-  SetState(StateType::eStateStopped);
+  SetCurrentThreadID(tids[0]);
+  SetState(StateType::eStateStopped, false);
 
-  if (error.Fail())
-    LLDB_LOG(log, "inferior launching failed {0}", error);
-  return error;
+  // Proccess any signals we received before installing our handler
+  SigchldHandler();
 }
 
-::pid_t NativeProcessLinux::Attach(lldb::pid_t pid, Status &error) {
+llvm::Expected<std::vector<::pid_t>> NativeProcessLinux::Attach(::pid_t pid) {
   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
 
+  Status status;
   // Use a map to keep track of the threads which we have attached/need to
   // attach.
   Host::TidMap tids_to_attach;
-  if (pid <= 1) {
-    error.SetErrorToGenericError();
-    error.SetErrorString("Attaching to process 1 is not allowed.");
-    return -1;
-  }
-
   while (Host::FindProcessThreads(pid, tids_to_attach)) {
     for (Host::TidMap::iterator it = tids_to_attach.begin();
          it != tids_to_attach.end();) {
@@ -423,48 +338,36 @@ Status NativeProcessLinux::LaunchInferior(MainLoop &mainloop,
 
         // Attach to the requested process.
         // An attach will cause the thread to stop with a SIGSTOP.
-        error = PtraceWrapper(PTRACE_ATTACH, tid);
-        if (error.Fail()) {
+        if ((status = PtraceWrapper(PTRACE_ATTACH, tid)).Fail()) {
           // No such thread. The thread may have exited.
           // More error handling may be needed.
-          if (error.GetError() == ESRCH) {
+          if (status.GetError() == ESRCH) {
             it = tids_to_attach.erase(it);
             continue;
-          } else
-            return -1;
+          }
+          return status.ToError();
         }
 
-        int status;
+        int wpid =
+            llvm::sys::RetryAfterSignal(-1, ::waitpid, tid, nullptr, __WALL);
         // Need to use __WALL otherwise we receive an error with errno=ECHLD
         // At this point we should have a thread stopped if waitpid succeeds.
-        if ((status = waitpid(tid, NULL, __WALL)) < 0) {
+        if (wpid < 0) {
           // No such thread. The thread may have exited.
           // More error handling may be needed.
           if (errno == ESRCH) {
             it = tids_to_attach.erase(it);
             continue;
-          } else {
-            error.SetErrorToErrno();
-            return -1;
           }
+          return llvm::errorCodeToError(
+              std::error_code(errno, std::generic_category()));
         }
 
-        error = SetDefaultPtraceOpts(tid);
-        if (error.Fail())
-          return -1;
+        if ((status = SetDefaultPtraceOpts(tid)).Fail())
+          return status.ToError();
 
         LLDB_LOG(log, "adding tid = {0}", tid);
         it->second = true;
-
-        // Create the thread, mark it as stopped.
-        NativeThreadLinuxSP thread_sp(AddThread(static_cast<lldb::tid_t>(tid)));
-        assert(thread_sp && "AddThread() returned a nullptr");
-
-        // This will notify this is a new thread and tell the system it is
-        // stopped.
-        thread_sp->SetStoppedBySignal(SIGSTOP);
-        ThreadWasCreated(*thread_sp);
-        SetCurrentThreadID(thread_sp->GetID());
       }
 
       // move the loop forward
@@ -472,17 +375,16 @@ Status NativeProcessLinux::LaunchInferior(MainLoop &mainloop,
     }
   }
 
-  if (tids_to_attach.size() > 0) {
-    m_pid = pid;
-    // Let our process instance know the thread has stopped.
-    SetState(StateType::eStateStopped);
-  } else {
-    error.SetErrorToGenericError();
-    error.SetErrorString("No such process.");
-    return -1;
-  }
+  size_t tid_count = tids_to_attach.size();
+  if (tid_count == 0)
+    return llvm::make_error<StringError>("No such process",
+                                         llvm::inconvertibleErrorCode());
 
-  return pid;
+  std::vector<::pid_t> tids;
+  tids.reserve(tid_count);
+  for (const auto &p : tids_to_attach)
+    tids.push_back(p.first);
+  return std::move(tids);
 }
 
 Status NativeProcessLinux::SetDefaultPtraceOpts(lldb::pid_t pid) {
@@ -662,14 +564,11 @@ void NativeProcessLinux::WaitForNewThread(::pid_t tid) {
 
   // The thread is not tracked yet, let's wait for it to appear.
   int status = -1;
-  ::pid_t wait_pid;
-  do {
-    LLDB_LOG(log,
-             "received thread creation event for tid {0}. tid not tracked "
-             "yet, waiting for thread to appear...",
-             tid);
-    wait_pid = waitpid(tid, &status, __WALL);
-  } while (wait_pid == -1 && errno == EINTR);
+  LLDB_LOG(log,
+           "received thread creation event for tid {0}. tid not tracked "
+           "yet, waiting for thread to appear...",
+           tid);
+  ::pid_t wait_pid = llvm::sys::RetryAfterSignal(-1, ::waitpid, tid, &status, __WALL);
   // Since we are waiting on a specific tid, this must be the creation event.
   // But let's do some checks just in case.
   if (wait_pid != tid) {
@@ -897,11 +796,9 @@ void NativeProcessLinux::MonitorSIGTRAP(const siginfo_t &info,
     break;
 
   default:
-    LLDB_LOG(
-        log,
-        "received unknown SIGTRAP stop event ({0}, pid {1} tid {2}, resuming",
-        info.si_code, GetID(), thread.GetID());
-    llvm_unreachable("Unexpected SIGTRAP code!");
+    LLDB_LOG(log, "received unknown SIGTRAP stop event ({0}, pid {1} tid {2}",
+             info.si_code, GetID(), thread.GetID());
+    MonitorSignal(info, thread, false);
     break;
   }
 }
@@ -2363,15 +2260,13 @@ void NativeProcessLinux::SigchldHandler() {
   // Process all pending waitpid notifications.
   while (true) {
     int status = -1;
-    ::pid_t wait_pid = waitpid(-1, &status, __WALL | __WNOTHREAD | WNOHANG);
+    ::pid_t wait_pid = llvm::sys::RetryAfterSignal(-1, ::waitpid, -1, &status,
+                                          __WALL | __WNOTHREAD | WNOHANG);
 
     if (wait_pid == 0)
       break; // We are done.
 
     if (wait_pid == -1) {
-      if (errno == EINTR)
-        continue;
-
       Status error(errno, eErrorTypePOSIX);
       LLDB_LOG(log, "waitpid (-1, &status, _) failed: {0}", error);
       break;
diff --git a/source/Plugins/Process/Linux/NativeProcessLinux.h b/source/Plugins/Process/Linux/NativeProcessLinux.h
index 6bf093f6a39a..9584713d3654 100644
--- a/source/Plugins/Process/Linux/NativeProcessLinux.h
+++ b/source/Plugins/Process/Linux/NativeProcessLinux.h
@@ -39,15 +39,18 @@ namespace process_linux {
 ///
 /// Changes in the inferior process state are broadcasted.
 class NativeProcessLinux : public NativeProcessProtocol {
-  friend Status NativeProcessProtocol::Launch(
-      ProcessLaunchInfo &launch_info, NativeDelegate &native_delegate,
-      MainLoop &mainloop, NativeProcessProtocolSP &process_sp);
+public:
+  class Factory : public NativeProcessProtocol::Factory {
+  public:
+    llvm::Expected<NativeProcessProtocolSP>
+    Launch(ProcessLaunchInfo &launch_info, NativeDelegate &native_delegate,
+           MainLoop &mainloop) const override;
 
-  friend Status NativeProcessProtocol::Attach(
-      lldb::pid_t pid, NativeProcessProtocol::NativeDelegate &native_delegate,
-      MainLoop &mainloop, NativeProcessProtocolSP &process_sp);
+    llvm::Expected<NativeProcessProtocolSP>
+    Attach(lldb::pid_t pid, NativeDelegate &native_delegate,
+           MainLoop &mainloop) const override;
+  };
 
-public:
   // ---------------------------------------------------------------------
   // NativeProcessProtocol Interface
   // ---------------------------------------------------------------------
@@ -144,10 +147,10 @@ private:
   MainLoop::SignalHandleUP m_sigchld_handle;
   ArchSpec m_arch;
 
-  LazyBool m_supports_mem_region;
+  LazyBool m_supports_mem_region = eLazyBoolCalculate;
   std::vector<std::pair<MemoryRegionInfo, FileSpec>> m_mem_region_cache;
 
-  lldb::tid_t m_pending_notification_tid;
+  lldb::tid_t m_pending_notification_tid = LLDB_INVALID_THREAD_ID;
 
   // List of thread ids stepping with a breakpoint with the address of
   // the relevan breakpoint
@@ -156,19 +159,15 @@ private:
   // ---------------------------------------------------------------------
   // Private Instance Methods
   // ---------------------------------------------------------------------
-  NativeProcessLinux();
-
-  Status LaunchInferior(MainLoop &mainloop, ProcessLaunchInfo &launch_info);
-
-  /// Attaches to an existing process.  Forms the
-  /// implementation of Process::DoAttach
-  void AttachToInferior(MainLoop &mainloop, lldb::pid_t pid, Status &error);
+  NativeProcessLinux(::pid_t pid, int terminal_fd, NativeDelegate &delegate,
+                     const ArchSpec &arch, MainLoop &mainloop);
 
-  ::pid_t Attach(lldb::pid_t pid, Status &error);
+  // Returns a list of process threads that we have attached to.
+  static llvm::Expected<std::vector<::pid_t>> Attach(::pid_t pid);
 
   static Status SetDefaultPtraceOpts(const lldb::pid_t);
 
-  static void *MonitorThread(void *baton);
+  void InitializeThreads(llvm::ArrayRef<::pid_t> tids);
 
   void MonitorCallback(lldb::pid_t pid, bool exited, WaitStatus status);
 
@@ -280,7 +279,7 @@ private:
   // same process user id.
   llvm::DenseSet<lldb::tid_t> m_pt_traced_thread_group;
 
-  lldb::user_id_t m_pt_proces_trace_id;
+  lldb::user_id_t m_pt_proces_trace_id = LLDB_INVALID_UID;
   TraceOptions m_pt_process_trace_config;
 };
 
diff --git a/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.cpp b/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.cpp
index c3b58f16256a..1a5b304ac697 100644
--- a/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.cpp
+++ b/source/Plugins/Process/Linux/NativeRegisterContextLinux_arm64.cpp
@@ -680,7 +680,7 @@ Status NativeRegisterContextLinux_arm64::ClearAllHardwareWatchpoints() {
     return error;
 
   lldb::addr_t tempAddr = 0;
-  uint32_t tempControl = 0, tempRefCount = 0;
+  uint32_t tempControl = 0;
 
   for (uint32_t i = 0; i < m_max_hwp_supported; i++) {
     if (m_hwp_regs[i].control & 0x01) {
@@ -858,7 +858,7 @@ Status NativeRegisterContextLinux_arm64::DoReadRegisterValue(
     RegisterValue &value) {
   Status error;
   if (offset > sizeof(struct user_pt_regs)) {
-    uintptr_t offset = offset - sizeof(struct user_pt_regs);
+    offset -= sizeof(struct user_pt_regs);
     if (offset > sizeof(struct user_fpsimd_state)) {
       error.SetErrorString("invalid offset value");
       return error;
@@ -905,7 +905,7 @@ Status NativeRegisterContextLinux_arm64::DoWriteRegisterValue(
   Status error;
   ::pid_t tid = m_thread.GetID();
   if (offset > sizeof(struct user_pt_regs)) {
-    uintptr_t offset = offset - sizeof(struct user_pt_regs);
+    offset -= sizeof(struct user_pt_regs);
     if (offset > sizeof(struct user_fpsimd_state)) {
       error.SetErrorString("invalid offset value");
       return error;
diff --git a/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp b/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp
index 59dc9e9f7d45..e44e03b46b5c 100755
--- a/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp
+++ b/source/Plugins/Process/Linux/NativeRegisterContextLinux_x86_64.cpp
@@ -646,13 +646,6 @@ Status NativeRegisterContextLinux_x86_64::ReadAllRegisterValues(
   Status error;
 
   data_sp.reset(new DataBufferHeap(REG_CONTEXT_SIZE, 0));
-  if (!data_sp) {
-    error.SetErrorStringWithFormat(
-        "failed to allocate DataBufferHeap instance of size %" PRIu64,
-        REG_CONTEXT_SIZE);
-    return error;
-  }
-
   error = ReadGPR();
   if (error.Fail())
     return error;
@@ -662,13 +655,6 @@ Status NativeRegisterContextLinux_x86_64::ReadAllRegisterValues(
     return error;
 
   uint8_t *dst = data_sp->GetBytes();
-  if (dst == nullptr) {
-    error.SetErrorStringWithFormat("DataBufferHeap instance of size %" PRIu64
-                                   " returned a null pointer",
-                                   REG_CONTEXT_SIZE);
-    return error;
-  }
-
   ::memcpy(dst, &m_gpr_x86_64, GetRegisterInfoInterface().GetGPRSize());
   dst += GetRegisterInfoInterface().GetGPRSize();
   if (m_xstate_type == XStateType::FXSAVE)
@@ -741,10 +727,9 @@ Status NativeRegisterContextLinux_x86_64::WriteAllRegisterValues(
   }
 
   if (data_sp->GetByteSize() != REG_CONTEXT_SIZE) {
-    error.SetErrorStringWithFormat(
-        "NativeRegisterContextLinux_x86_64::%s data_sp contained mismatched "
-        "data size, expected %" PRIu64 ", actual %" PRIu64,
-        __FUNCTION__, REG_CONTEXT_SIZE, data_sp->GetByteSize());
+    error.SetErrorStringWithFormatv(
+        "data_sp contained mismatched data size, expected {0}, actual {1}",
+        REG_CONTEXT_SIZE, data_sp->GetByteSize());
     return error;
   }
 
diff --git a/source/Plugins/Process/Linux/ProcessorTrace.cpp b/source/Plugins/Process/Linux/ProcessorTrace.cpp
index 7043d50256e6..505c526ab70d 100644
--- a/source/Plugins/Process/Linux/ProcessorTrace.cpp
+++ b/source/Plugins/Process/Linux/ProcessorTrace.cpp
@@ -46,13 +46,11 @@ Status ProcessorTraceMonitor::GetTraceConfig(TraceOptions &config) const {
 
 Status ProcessorTraceMonitor::StartTrace(lldb::pid_t pid, lldb::tid_t tid,
                                          const TraceOptions &config) {
-  Status error;
-  Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PTRACE));
-  LLDB_LOG(log, "{0}", config.getThreadID());
-
 #ifndef PERF_ATTR_SIZE_VER5
   llvm_unreachable("perf event not supported");
 #else
+  Status error;
+  Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PTRACE));
 
   LLDB_LOG(log, "called thread id {0}", tid);
   uint64_t page_size = getpagesize();
@@ -61,12 +59,11 @@ Status ProcessorTraceMonitor::StartTrace(lldb::pid_t pid, lldb::tid_t tid,
 
   uint64_t numpages = static_cast<uint64_t>(
       llvm::PowerOf2Floor((bufsize + page_size - 1) / page_size));
-  numpages = std::max(1ul, numpages);
+  numpages = std::max<uint64_t>(1, numpages);
   bufsize = page_size * numpages;
 
   numpages = static_cast<uint64_t>(
       llvm::PowerOf2Floor((metabufsize + page_size - 1) / page_size));
-  numpages = std::max(0ul, numpages);
   metabufsize = page_size * numpages;
 
   perf_event_attr attr;
@@ -117,7 +114,7 @@ Status ProcessorTraceMonitor::StartTrace(lldb::pid_t pid, lldb::tid_t tid,
     return error;
   }
 
-  m_fd = std::move(std::unique_ptr<int, file_close>(new int(fd), file_close()));
+  m_fd = std::unique_ptr<int, file_close>(new int(fd), file_close());
 
   errno = 0;
   auto base =
@@ -129,9 +126,9 @@ Status ProcessorTraceMonitor::StartTrace(lldb::pid_t pid, lldb::tid_t tid,
     return error;
   }
 
-  m_mmap_meta = std::move(std::unique_ptr<perf_event_mmap_page, munmap_delete>(
+  m_mmap_meta = std::unique_ptr<perf_event_mmap_page, munmap_delete>(
       reinterpret_cast<perf_event_mmap_page *>(base),
-      munmap_delete(metabufsize + page_size)));
+      munmap_delete(metabufsize + page_size));
 
   m_mmap_meta->aux_offset = m_mmap_meta->data_offset + m_mmap_meta->data_size;
   m_mmap_meta->aux_size = bufsize;
@@ -145,10 +142,10 @@ Status ProcessorTraceMonitor::StartTrace(lldb::pid_t pid, lldb::tid_t tid,
     error.SetErrorString("Trace buffer allocation failed");
     return error;
   }
-  m_mmap_aux = std::move(std::unique_ptr<uint8_t, munmap_delete>(
-      reinterpret_cast<uint8_t *>(mmap_aux), munmap_delete(bufsize)));
-#endif
+  m_mmap_aux = std::unique_ptr<uint8_t, munmap_delete>(
+      reinterpret_cast<uint8_t *>(mmap_aux), munmap_delete(bufsize));
   return error;
+#endif
 }
 
 llvm::MutableArrayRef<uint8_t> ProcessorTraceMonitor::GetDataBuffer() {
@@ -251,14 +248,14 @@ ProcessorTraceMonitor::Create(lldb::pid_t pid, lldb::tid_t tid,
   Status error;
   if (tid == LLDB_INVALID_THREAD_ID) {
     error.SetErrorString("thread not specified");
-    return std::move(error.ToError());
+    return error.ToError();
   }
 
   ProcessorTraceMonitorUP pt_monitor_up(new ProcessorTraceMonitor);
 
   error = pt_monitor_up->StartTrace(pid, tid, config);
   if (error.Fail())
-    return std::move(error.ToError());
+    return error.ToError();
 
   pt_monitor_up->SetThreadID(tid);
 
@@ -274,13 +271,11 @@ ProcessorTraceMonitor::Create(lldb::pid_t pid, lldb::tid_t tid,
 Status
 ProcessorTraceMonitor::ReadPerfTraceAux(llvm::MutableArrayRef<uint8_t> &buffer,
                                         size_t offset) {
-
-  Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PTRACE));
-  Status error;
-
 #ifndef PERF_ATTR_SIZE_VER5
   llvm_unreachable("perf event not supported");
 #else
+  Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PTRACE));
+  Status error;
   uint64_t head = m_mmap_meta->aux_head;
 
   LLDB_LOG(log, "Aux size -{0} , Head - {1}", m_mmap_meta->aux_size, head);
@@ -306,12 +301,12 @@ ProcessorTraceMonitor::ReadPerfTraceAux(llvm::MutableArrayRef<uint8_t> &buffer,
 Status
 ProcessorTraceMonitor::ReadPerfTraceData(llvm::MutableArrayRef<uint8_t> &buffer,
                                          size_t offset) {
-  Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PTRACE));
-  uint64_t bytes_remaining = buffer.size();
-  Status error;
 #ifndef PERF_ATTR_SIZE_VER5
   llvm_unreachable("perf event not supported");
 #else
+  Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PTRACE));
+  uint64_t bytes_remaining = buffer.size();
+  Status error;
 
   uint64_t head = m_mmap_meta->data_head;
 
diff --git a/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp b/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
index a4d775860a65..b9ef02efa65d 100644
--- a/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
+++ b/source/Plugins/Process/NetBSD/NativeProcessNetBSD.cpp
@@ -21,6 +21,7 @@
 #include "lldb/Host/common/NativeRegisterContext.h"
 #include "lldb/Host/posix/ProcessLauncherPosixFork.h"
 #include "lldb/Target/Process.h"
+#include "llvm/Support/Errno.h"
 
 // System includes - They have to be included after framework includes because
 // they define some
@@ -63,81 +64,101 @@ static Status EnsureFDFlags(int fd, int flags) {
 // Public Static Methods
 // -----------------------------------------------------------------------------
 
-Status NativeProcessProtocol::Launch(
-    ProcessLaunchInfo &launch_info,
-    NativeProcessProtocol::NativeDelegate &native_delegate, MainLoop &mainloop,
-    NativeProcessProtocolSP &native_process_sp) {
+llvm::Expected<NativeProcessProtocolSP>
+NativeProcessNetBSD::Factory::Launch(ProcessLaunchInfo &launch_info,
+                                     NativeDelegate &native_delegate,
+                                     MainLoop &mainloop) const {
   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
 
-  Status error;
+  Status status;
+  ::pid_t pid = ProcessLauncherPosixFork()
+                    .LaunchProcess(launch_info, status)
+                    .GetProcessId();
+  LLDB_LOG(log, "pid = {0:x}", pid);
+  if (status.Fail()) {
+    LLDB_LOG(log, "failed to launch process: {0}", status);
+    return status.ToError();
+  }
 
-  // Verify the working directory is valid if one was specified.
-  FileSpec working_dir{launch_info.GetWorkingDirectory()};
-  if (working_dir && (!working_dir.ResolvePath() ||
-                      !llvm::sys::fs::is_directory(working_dir.GetPath()))) {
-    error.SetErrorStringWithFormat("No such file or directory: %s",
-                                   working_dir.GetCString());
-    return error;
+  // Wait for the child process to trap on its call to execve.
+  int wstatus;
+  ::pid_t wpid = llvm::sys::RetryAfterSignal(-1, ::waitpid, pid, &wstatus, 0);
+  assert(wpid == pid);
+  (void)wpid;
+  if (!WIFSTOPPED(wstatus)) {
+    LLDB_LOG(log, "Could not sync with inferior process: wstatus={1}",
+             WaitStatus::Decode(wstatus));
+    return llvm::make_error<StringError>("Could not sync with inferior process",
+                                         llvm::inconvertibleErrorCode());
   }
+  LLDB_LOG(log, "inferior started, now in stopped state");
 
-  // Create the NativeProcessNetBSD in launch mode.
-  native_process_sp.reset(new NativeProcessNetBSD());
+  ArchSpec arch;
+  if ((status = ResolveProcessArchitecture(pid, arch)).Fail())
+    return status.ToError();
 
-  if (!native_process_sp->RegisterNativeDelegate(native_delegate)) {
-    native_process_sp.reset();
-    error.SetErrorStringWithFormat("failed to register the native delegate");
-    return error;
-  }
+  // Set the architecture to the exe architecture.
+  LLDB_LOG(log, "pid = {0:x}, detected architecture {1}", pid,
+           arch.GetArchitectureName());
 
-  error = std::static_pointer_cast<NativeProcessNetBSD>(native_process_sp)
-              ->LaunchInferior(mainloop, launch_info);
+  std::shared_ptr<NativeProcessNetBSD> process_sp(new NativeProcessNetBSD(
+      pid, launch_info.GetPTY().ReleaseMasterFileDescriptor(), native_delegate,
+      arch, mainloop));
 
-  if (error.Fail()) {
-    native_process_sp.reset();
-    LLDB_LOG(log, "failed to launch process: {0}", error);
-    return error;
-  }
+  status = process_sp->ReinitializeThreads();
+  if (status.Fail())
+    return status.ToError();
 
-  launch_info.SetProcessID(native_process_sp->GetID());
+  for (const auto &thread_sp : process_sp->m_threads) {
+    static_pointer_cast<NativeThreadNetBSD>(thread_sp)->SetStoppedBySignal(
+        SIGSTOP);
+  }
+  process_sp->SetState(StateType::eStateStopped);
 
-  return error;
+  return process_sp;
 }
 
-Status NativeProcessProtocol::Attach(
+llvm::Expected<NativeProcessProtocolSP> NativeProcessNetBSD::Factory::Attach(
     lldb::pid_t pid, NativeProcessProtocol::NativeDelegate &native_delegate,
-    MainLoop &mainloop, NativeProcessProtocolSP &native_process_sp) {
+    MainLoop &mainloop) const {
   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
   LLDB_LOG(log, "pid = {0:x}", pid);
 
   // Retrieve the architecture for the running process.
-  ArchSpec process_arch;
-  Status error = ResolveProcessArchitecture(pid, process_arch);
-  if (!error.Success())
-    return error;
+  ArchSpec arch;
+  Status status = ResolveProcessArchitecture(pid, arch);
+  if (!status.Success())
+    return status.ToError();
 
-  std::shared_ptr<NativeProcessNetBSD> native_process_netbsd_sp(
-      new NativeProcessNetBSD());
+  std::shared_ptr<NativeProcessNetBSD> process_sp(
+      new NativeProcessNetBSD(pid, -1, native_delegate, arch, mainloop));
 
-  if (!native_process_netbsd_sp->RegisterNativeDelegate(native_delegate)) {
-    error.SetErrorStringWithFormat("failed to register the native delegate");
-    return error;
-  }
-
-  native_process_netbsd_sp->AttachToInferior(mainloop, pid, error);
-  if (!error.Success())
-    return error;
+  status = process_sp->Attach();
+  if (!status.Success())
+    return status.ToError();
 
-  native_process_sp = native_process_netbsd_sp;
-  return error;
+  return process_sp;
 }
 
 // -----------------------------------------------------------------------------
 // Public Instance Methods
 // -----------------------------------------------------------------------------
 
-NativeProcessNetBSD::NativeProcessNetBSD()
-    : NativeProcessProtocol(LLDB_INVALID_PROCESS_ID), m_arch(),
-      m_supports_mem_region(eLazyBoolCalculate), m_mem_region_cache() {}
+NativeProcessNetBSD::NativeProcessNetBSD(::pid_t pid, int terminal_fd,
+                                         NativeDelegate &delegate,
+                                         const ArchSpec &arch,
+                                         MainLoop &mainloop)
+    : NativeProcessProtocol(pid, terminal_fd, delegate), m_arch(arch) {
+  if (m_terminal_fd != -1) {
+    Status status = EnsureFDFlags(m_terminal_fd, O_NONBLOCK);
+    assert(status.Success());
+  }
+
+  Status status;
+  m_sigchld_handle = mainloop.RegisterSignal(
+      SIGCHLD, [this](MainLoopBase &) { SigchldHandler(); }, status);
+  assert(m_sigchld_handle && status.Success());
+}
 
 // Handles all waitpid events from the inferior process.
 void NativeProcessNetBSD::MonitorCallback(lldb::pid_t pid, int signal) {
@@ -709,126 +730,17 @@ Status NativeProcessNetBSD::GetFileLoadAddress(const llvm::StringRef &file_name,
   return Status();
 }
 
-Status NativeProcessNetBSD::LaunchInferior(MainLoop &mainloop,
-                                           ProcessLaunchInfo &launch_info) {
-  Status error;
-  m_sigchld_handle = mainloop.RegisterSignal(
-      SIGCHLD, [this](MainLoopBase &) { SigchldHandler(); }, error);
-  if (!m_sigchld_handle)
-    return error;
-
-  SetState(eStateLaunching);
-
-  ::pid_t pid = ProcessLauncherPosixFork()
-                    .LaunchProcess(launch_info, error)
-                    .GetProcessId();
-  if (error.Fail())
-    return error;
-
-  Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
-
-  // Wait for the child process to trap on its call to execve.
-  ::pid_t wpid;
-  int status;
-  if ((wpid = waitpid(pid, &status, 0)) < 0) {
-    error.SetErrorToErrno();
-    LLDB_LOG(log, "waitpid for inferior failed with %s", error);
-
-    // Mark the inferior as invalid.
-    // FIXME this could really use a new state - eStateLaunchFailure.  For
-    // now, using eStateInvalid.
-    SetState(StateType::eStateInvalid);
-
-    return error;
-  }
-  assert(WIFSTOPPED(status) && (wpid == static_cast<::pid_t>(pid)) &&
-         "Could not sync with inferior process.");
-
-  LLDB_LOG(log, "inferior started, now in stopped state");
-
-  // Release the master terminal descriptor and pass it off to the
-  // NativeProcessNetBSD instance.  Similarly stash the inferior pid.
-  m_terminal_fd = launch_info.GetPTY().ReleaseMasterFileDescriptor();
-  m_pid = pid;
-  launch_info.SetProcessID(pid);
-
-  if (m_terminal_fd != -1) {
-    error = EnsureFDFlags(m_terminal_fd, O_NONBLOCK);
-    if (error.Fail()) {
-      LLDB_LOG(log,
-               "inferior EnsureFDFlags failed for ensuring terminal "
-               "O_NONBLOCK setting: {0}",
-               error);
-
-      // Mark the inferior as invalid.
-      // FIXME this could really use a new state - eStateLaunchFailure.  For
-      // now, using eStateInvalid.
-      SetState(StateType::eStateInvalid);
-
-      return error;
-    }
-  }
-
-  LLDB_LOG(log, "adding pid = {0}", pid);
-
-  ResolveProcessArchitecture(m_pid, m_arch);
-
-  error = ReinitializeThreads();
-  if (error.Fail()) {
-    SetState(StateType::eStateInvalid);
-    return error;
-  }
-
-  for (const auto &thread_sp : m_threads) {
-    static_pointer_cast<NativeThreadNetBSD>(thread_sp)->SetStoppedBySignal(
-        SIGSTOP);
-  }
-
-  /* Set process stopped */
-  SetState(StateType::eStateStopped);
-
-  if (error.Fail())
-    LLDB_LOG(log, "inferior launching failed {0}", error);
-  return error;
-}
-
-void NativeProcessNetBSD::AttachToInferior(MainLoop &mainloop, lldb::pid_t pid,
-                                           Status &error) {
-  Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
-  LLDB_LOG(log, "pid = {0:x}", pid);
-
-  m_sigchld_handle = mainloop.RegisterSignal(
-      SIGCHLD, [this](MainLoopBase &) { SigchldHandler(); }, error);
-  if (!m_sigchld_handle)
-    return;
-
-  error = ResolveProcessArchitecture(pid, m_arch);
-  if (!error.Success())
-    return;
-
-  // Set the architecture to the exe architecture.
-  LLDB_LOG(log, "pid = {0:x}, detected architecture {1}", pid,
-           m_arch.GetArchitectureName());
-
-  m_pid = pid;
-  SetState(eStateAttaching);
-
-  Attach(pid, error);
-}
-
 void NativeProcessNetBSD::SigchldHandler() {
   Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PROCESS));
   // Process all pending waitpid notifications.
   int status;
-  ::pid_t wait_pid = waitpid(GetID(), &status, WALLSIG | WNOHANG);
+  ::pid_t wait_pid =
+      llvm::sys::RetryAfterSignal(-1, waitpid, GetID(), &status, WALLSIG | WNOHANG);
 
   if (wait_pid == 0)
     return; // We are done.
 
   if (wait_pid == -1) {
-    if (errno == EINTR)
-      return;
-
     Status error(errno, eErrorTypePOSIX);
     LLDB_LOG(log, "waitpid ({0}, &status, _) failed: {1}", GetID(), error);
   }
@@ -880,33 +792,23 @@ NativeThreadNetBSDSP NativeProcessNetBSD::AddThread(lldb::tid_t thread_id) {
   return thread_sp;
 }
 
-::pid_t NativeProcessNetBSD::Attach(lldb::pid_t pid, Status &error) {
-  if (pid <= 1) {
-    error.SetErrorToGenericError();
-    error.SetErrorString("Attaching to process 1 is not allowed.");
-    return -1;
-  }
-
+Status NativeProcessNetBSD::Attach() {
   // Attach to the requested process.
   // An attach will cause the thread to stop with a SIGSTOP.
-  error = PtraceWrapper(PT_ATTACH, pid);
-  if (error.Fail())
-    return -1;
+  Status status = PtraceWrapper(PT_ATTACH, m_pid);
+  if (status.Fail())
+    return status;
 
-  int status;
+  int wstatus;
   // Need to use WALLSIG otherwise we receive an error with errno=ECHLD
   // At this point we should have a thread stopped if waitpid succeeds.
-  if ((status = waitpid(pid, NULL, WALLSIG)) < 0)
-    return -1;
-
-  m_pid = pid;
+  if ((wstatus = waitpid(m_pid, NULL, WALLSIG)) < 0)
+    return Status(errno, eErrorTypePOSIX);
 
   /* Initialize threads */
-  error = ReinitializeThreads();
-  if (error.Fail()) {
-    SetState(StateType::eStateInvalid);
-    return -1;
-  }
+  status = ReinitializeThreads();
+  if (status.Fail())
+    return status;
 
   for (const auto &thread_sp : m_threads) {
     static_pointer_cast<NativeThreadNetBSD>(thread_sp)->SetStoppedBySignal(
@@ -915,8 +817,7 @@ NativeThreadNetBSDSP NativeProcessNetBSD::AddThread(lldb::tid_t thread_id) {
 
   // Let our process instance know the thread has stopped.
   SetState(StateType::eStateStopped);
-
-  return pid;
+  return Status();
 }
 
 Status NativeProcessNetBSD::ReadMemory(lldb::addr_t addr, void *buf,
diff --git a/source/Plugins/Process/NetBSD/NativeProcessNetBSD.h b/source/Plugins/Process/NetBSD/NativeProcessNetBSD.h
index 7a1303faea68..34b892f1fc88 100644
--- a/source/Plugins/Process/NetBSD/NativeProcessNetBSD.h
+++ b/source/Plugins/Process/NetBSD/NativeProcessNetBSD.h
@@ -31,15 +31,18 @@ namespace process_netbsd {
 ///
 /// Changes in the inferior process state are broadcasted.
 class NativeProcessNetBSD : public NativeProcessProtocol {
-  friend Status NativeProcessProtocol::Launch(
-      ProcessLaunchInfo &launch_info, NativeDelegate &native_delegate,
-      MainLoop &mainloop, NativeProcessProtocolSP &process_sp);
+public:
+  class Factory : public NativeProcessProtocol::Factory {
+  public:
+    llvm::Expected<NativeProcessProtocolSP>
+    Launch(ProcessLaunchInfo &launch_info, NativeDelegate &native_delegate,
+           MainLoop &mainloop) const override;
 
-  friend Status NativeProcessProtocol::Attach(
-      lldb::pid_t pid, NativeProcessProtocol::NativeDelegate &native_delegate,
-      MainLoop &mainloop, NativeProcessProtocolSP &process_sp);
+    llvm::Expected<NativeProcessProtocolSP>
+    Attach(lldb::pid_t pid, NativeDelegate &native_delegate,
+           MainLoop &mainloop) const override;
+  };
 
-public:
   // ---------------------------------------------------------------------
   // NativeProcessProtocol Interface
   // ---------------------------------------------------------------------
@@ -107,21 +110,19 @@ protected:
 private:
   MainLoop::SignalHandleUP m_sigchld_handle;
   ArchSpec m_arch;
-  LazyBool m_supports_mem_region;
+  LazyBool m_supports_mem_region = eLazyBoolCalculate;
   std::vector<std::pair<MemoryRegionInfo, FileSpec>> m_mem_region_cache;
 
   // ---------------------------------------------------------------------
   // Private Instance Methods
   // ---------------------------------------------------------------------
-  NativeProcessNetBSD();
+  NativeProcessNetBSD(::pid_t pid, int terminal_fd, NativeDelegate &delegate,
+                      const ArchSpec &arch, MainLoop &mainloop);
 
   bool HasThreadNoLock(lldb::tid_t thread_id);
 
   NativeThreadNetBSDSP AddThread(lldb::tid_t thread_id);
 
-  Status LaunchInferior(MainLoop &mainloop, ProcessLaunchInfo &launch_info);
-  void AttachToInferior(MainLoop &mainloop, lldb::pid_t pid, Status &error);
-
   void MonitorCallback(lldb::pid_t pid, int signal);
   void MonitorExited(lldb::pid_t pid, WaitStatus status);
   void MonitorSIGSTOP(lldb::pid_t pid);
@@ -133,8 +134,7 @@ private:
   Status PopulateMemoryRegionCache();
   void SigchldHandler();
 
-  ::pid_t Attach(lldb::pid_t pid, Status &error);
-
+  Status Attach();
   Status ReinitializeThreads();
 };
 
diff --git a/source/Plugins/Process/gdb-remote/CMakeLists.txt b/source/Plugins/Process/gdb-remote/CMakeLists.txt
index 3d008f42499d..5e51feef1d3f 100644
--- a/source/Plugins/Process/gdb-remote/CMakeLists.txt
+++ b/source/Plugins/Process/gdb-remote/CMakeLists.txt
@@ -7,14 +7,6 @@ set(LLDB_PLUGINS
   lldbPluginPlatformMacOSX
 )
 
-if(CMAKE_SYSTEM_NAME MATCHES "Linux|Android")
-  list(APPEND LLDB_PLUGINS lldbPluginProcessLinux)
-endif()
-
-if(CMAKE_SYSTEM_NAME MATCHES "NetBSD")
-  list(APPEND LLDB_PLUGINS lldbPluginProcessNetBSD)
-endif()
-
 add_lldb_library(lldbPluginProcessGDBRemote PLUGIN
   GDBRemoteClientBase.cpp
   GDBRemoteCommunication.cpp
diff --git a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
index 33aed7a43c4a..e6fd386b903b 100644
--- a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
+++ b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
@@ -86,6 +86,7 @@ GDBRemoteCommunicationClient::GDBRemoteCommunicationClient()
       m_supports_jLoadedDynamicLibrariesInfos(eLazyBoolCalculate),
       m_supports_jGetSharedCacheInfo(eLazyBoolCalculate),
       m_supports_QPassSignals(eLazyBoolCalculate),
+      m_supports_error_string_reply(eLazyBoolCalculate),
       m_supports_qProcessInfoPID(true), m_supports_qfProcessInfo(true),
       m_supports_qUserName(true), m_supports_qGroupName(true),
       m_supports_qThreadStopInfo(true), m_supports_z0(true),
@@ -596,6 +597,21 @@ bool GDBRemoteCommunicationClient::GetThreadExtendedInfoSupported() {
   return m_supports_jThreadExtendedInfo;
 }
 
+void GDBRemoteCommunicationClient::EnableErrorStringInPacket() {
+  if (m_supports_error_string_reply == eLazyBoolCalculate) {
+    StringExtractorGDBRemote response;
+    // We try to enable error strings in remote packets
+    // but if we fail, we just work in the older way.
+    m_supports_error_string_reply = eLazyBoolNo;
+    if (SendPacketAndWaitForResponse("QEnableErrorStrings", response, false) ==
+        PacketResult::Success) {
+      if (response.IsOKResponse()) {
+        m_supports_error_string_reply = eLazyBoolYes;
+      }
+    }
+  }
+}
+
 bool GDBRemoteCommunicationClient::GetLoadedDynamicLibrariesInfosSupported() {
   if (m_supports_jLoadedDynamicLibrariesInfos == eLazyBoolCalculate) {
     StringExtractorGDBRemote response;
@@ -3181,8 +3197,8 @@ GDBRemoteCommunicationClient::SendStartTracePacket(const TraceOptions &options,
                                    true) ==
       GDBRemoteCommunication::PacketResult::Success) {
     if (!response.IsNormalResponse()) {
-      error.SetError(response.GetError(), eErrorTypeGeneric);
-      LLDB_LOG(log, "Target does not support Tracing");
+      error = response.GetStatus();
+      LLDB_LOG(log, "Target does not support Tracing , error {0}", error);
     } else {
       ret_uid = response.GetHexMaxU64(false, LLDB_INVALID_UID);
     }
@@ -3219,7 +3235,7 @@ GDBRemoteCommunicationClient::SendStopTracePacket(lldb::user_id_t uid,
                                    true) ==
       GDBRemoteCommunication::PacketResult::Success) {
     if (!response.IsOKResponse()) {
-      error.SetError(response.GetError(), eErrorTypeGeneric);
+      error = response.GetStatus();
       LLDB_LOG(log, "stop tracing failed");
     }
   } else {
@@ -3234,6 +3250,7 @@ GDBRemoteCommunicationClient::SendStopTracePacket(lldb::user_id_t uid,
 Status GDBRemoteCommunicationClient::SendGetDataPacket(
     lldb::user_id_t uid, lldb::tid_t thread_id,
     llvm::MutableArrayRef<uint8_t> &buffer, size_t offset) {
+
   StreamGDBRemote escaped_packet;
   escaped_packet.PutCString("jTraceBufferRead:");
   return SendGetTraceDataPacket(escaped_packet, uid, thread_id, buffer, offset);
@@ -3242,6 +3259,7 @@ Status GDBRemoteCommunicationClient::SendGetDataPacket(
 Status GDBRemoteCommunicationClient::SendGetMetaDataPacket(
     lldb::user_id_t uid, lldb::tid_t thread_id,
     llvm::MutableArrayRef<uint8_t> &buffer, size_t offset) {
+
   StreamGDBRemote escaped_packet;
   escaped_packet.PutCString("jTraceMetaRead:");
   return SendGetTraceDataPacket(escaped_packet, uid, thread_id, buffer, offset);
@@ -3308,7 +3326,7 @@ GDBRemoteCommunicationClient::SendGetTraceConfigPacket(lldb::user_id_t uid,
                   custom_params_sp));
       }
     } else {
-      error.SetError(response.GetError(), eErrorTypeGeneric);
+      error = response.GetStatus();
     }
   } else {
     LLDB_LOG(log, "failed to send packet");
@@ -3344,7 +3362,7 @@ Status GDBRemoteCommunicationClient::SendGetTraceDataPacket(
       size_t filled_size = response.GetHexBytesAvail(buffer);
       buffer = llvm::MutableArrayRef<uint8_t>(buffer.data(), filled_size);
     } else {
-      error.SetError(response.GetError(), eErrorTypeGeneric);
+      error = response.GetStatus();
       buffer = buffer.slice(buffer.size());
     }
   } else {
diff --git a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
index a38110faaec6..712d85eed082 100644
--- a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
+++ b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
@@ -340,6 +340,8 @@ public:
 
   bool GetQXferAuxvReadSupported();
 
+  void EnableErrorStringInPacket();
+
   bool GetQXferLibrariesReadSupported();
 
   bool GetQXferLibrariesSVR4ReadSupported();
@@ -549,6 +551,7 @@ protected:
   LazyBool m_supports_jLoadedDynamicLibrariesInfos;
   LazyBool m_supports_jGetSharedCacheInfo;
   LazyBool m_supports_QPassSignals;
+  LazyBool m_supports_error_string_reply;
 
   bool m_supports_qProcessInfoPID : 1, m_supports_qfProcessInfo : 1,
       m_supports_qUserName : 1, m_supports_qGroupName : 1,
diff --git a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.cpp b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.cpp
index dac675ee9432..4be92b79fd1a 100644
--- a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.cpp
+++ b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.cpp
@@ -20,6 +20,7 @@
 // Project includes
 #include "ProcessGDBRemoteLog.h"
 #include "Utility/StringExtractorGDBRemote.h"
+#include "lldb/Utility/StreamString.h"
 
 using namespace lldb;
 using namespace lldb_private;
@@ -27,7 +28,12 @@ using namespace lldb_private::process_gdb_remote;
 
 GDBRemoteCommunicationServer::GDBRemoteCommunicationServer(
     const char *comm_name, const char *listener_name)
-    : GDBRemoteCommunication(comm_name, listener_name), m_exit_now(false) {}
+    : GDBRemoteCommunication(comm_name, listener_name), m_exit_now(false) {
+  RegisterPacketHandler(
+      StringExtractorGDBRemote::eServerPacketType_QEnableErrorStrings,
+      [this](StringExtractorGDBRemote packet, Status &error, bool &interrupt,
+             bool &quit) { return this->Handle_QErrorStringEnable(packet); });
+}
 
 GDBRemoteCommunicationServer::~GDBRemoteCommunicationServer() {}
 
@@ -100,6 +106,24 @@ GDBRemoteCommunicationServer::SendErrorResponse(uint8_t err) {
 }
 
 GDBRemoteCommunication::PacketResult
+GDBRemoteCommunicationServer::SendErrorResponse(const Status &error) {
+  if (m_send_error_strings) {
+    lldb_private::StreamString packet;
+    packet.Printf("E%2.2x;", static_cast<uint8_t>(error.GetError()));
+    packet.PutCStringAsRawHex8(error.AsCString());
+    return SendPacketNoLock(packet.GetString());
+  } else
+    return SendErrorResponse(error.GetError());
+}
+
+GDBRemoteCommunication::PacketResult
+GDBRemoteCommunicationServer::Handle_QErrorStringEnable(
+    StringExtractorGDBRemote &packet) {
+  m_send_error_strings = true;
+  return SendOKResponse();
+}
+
+GDBRemoteCommunication::PacketResult
 GDBRemoteCommunicationServer::SendIllFormedResponse(
     const StringExtractorGDBRemote &failed_packet, const char *message) {
   Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PACKETS));
diff --git a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.h b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.h
index 6eb25f8b9f98..a35352480040 100644
--- a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.h
+++ b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.h
@@ -57,6 +57,13 @@ protected:
   bool m_exit_now; // use in asynchronous handling to indicate process should
                    // exit.
 
+  bool m_send_error_strings; // If the client enables this then
+                             // we will send error strings as well.
+
+  PacketResult Handle_QErrorStringEnable(StringExtractorGDBRemote &packet);
+
+  PacketResult SendErrorResponse(const Status &error);
+
   PacketResult SendUnimplementedResponse(const char *packet);
 
   PacketResult SendErrorResponse(uint8_t error);
diff --git a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
index de2400c51ba3..f53db502be93 100644
--- a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
+++ b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp
@@ -1046,14 +1046,9 @@ GDBRemoteCommunicationServerCommon::Handle_A(StringExtractorGDBRemote &packet) {
 
   if (success) {
     m_process_launch_error = LaunchProcess();
-    if (m_process_launch_info.GetProcessID() != LLDB_INVALID_PROCESS_ID) {
+    if (m_process_launch_error.Success())
       return SendOKResponse();
-    } else {
-      Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PROCESS));
-      if (log)
-        log->Printf("LLGSPacketHandler::%s failed to launch exe: %s",
-                    __FUNCTION__, m_process_launch_error.AsCString());
-    }
+    LLDB_LOG(log, "failed to launch exe: {0}", m_process_launch_error);
   }
   return SendErrorResponse(8);
 }
diff --git a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
index 7523260c13e4..a7fe4ee3b147 100644
--- a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
+++ b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
@@ -73,15 +73,11 @@ enum GDBRemoteServerError {
 // GDBRemoteCommunicationServerLLGS constructor
 //----------------------------------------------------------------------
 GDBRemoteCommunicationServerLLGS::GDBRemoteCommunicationServerLLGS(
-    MainLoop &mainloop)
+    MainLoop &mainloop, const NativeProcessProtocol::Factory &process_factory)
     : GDBRemoteCommunicationServerCommon("gdb-remote.server",
                                          "gdb-remote.server.rx_packet"),
-      m_mainloop(mainloop), m_current_tid(LLDB_INVALID_THREAD_ID),
-      m_continue_tid(LLDB_INVALID_THREAD_ID), m_debugged_process_mutex(),
-      m_debugged_process_sp(), m_stdio_communication("process.stdio"),
-      m_inferior_prev_state(StateType::eStateInvalid),
-      m_saved_registers_map(), m_next_saved_registers_id(1),
-      m_handshake_completed(false) {
+      m_mainloop(mainloop), m_process_factory(process_factory),
+      m_stdio_communication("process.stdio") {
   RegisterPacketHandlers();
 }
 
@@ -241,19 +237,20 @@ Status GDBRemoteCommunicationServerLLGS::LaunchProcess() {
   const bool default_to_use_pty = true;
   m_process_launch_info.FinalizeFileActions(nullptr, default_to_use_pty);
 
-  Status error;
   {
     std::lock_guard<std::recursive_mutex> guard(m_debugged_process_mutex);
     assert(!m_debugged_process_sp && "lldb-server creating debugged "
                                      "process but one already exists");
-    error = NativeProcessProtocol::Launch(m_process_launch_info, *this,
-                                          m_mainloop, m_debugged_process_sp);
-  }
-
-  if (!error.Success()) {
-    fprintf(stderr, "%s: failed to launch executable %s", __FUNCTION__,
-            m_process_launch_info.GetArguments().GetArgumentAtIndex(0));
-    return error;
+    auto process_or =
+        m_process_factory.Launch(m_process_launch_info, *this, m_mainloop);
+    if (!process_or) {
+      Status status(process_or.takeError());
+      llvm::errs() << llvm::formatv(
+          "failed to launch executable `{0}`: {1}",
+          m_process_launch_info.GetArguments().GetArgumentAtIndex(0), status);
+      return status;
+    }
+    m_debugged_process_sp = *process_or;
   }
 
   // Handle mirroring of inferior stdout/stderr over the gdb-remote protocol
@@ -279,9 +276,9 @@ Status GDBRemoteCommunicationServerLLGS::LaunchProcess() {
         log->Printf("ProcessGDBRemoteCommunicationServerLLGS::%s setting "
                     "inferior STDIO fd to %d",
                     __FUNCTION__, terminal_fd);
-      error = SetSTDIOFileDescriptor(terminal_fd);
-      if (error.Fail())
-        return error;
+      Status status = SetSTDIOFileDescriptor(terminal_fd);
+      if (status.Fail())
+        return status;
     } else {
       if (log)
         log->Printf("ProcessGDBRemoteCommunicationServerLLGS::%s ignoring "
@@ -298,14 +295,12 @@ Status GDBRemoteCommunicationServerLLGS::LaunchProcess() {
 
   printf("Launched '%s' as process %" PRIu64 "...\n",
          m_process_launch_info.GetArguments().GetArgumentAtIndex(0),
-         m_process_launch_info.GetProcessID());
+         m_debugged_process_sp->GetID());
 
-  return error;
+  return Status();
 }
 
 Status GDBRemoteCommunicationServerLLGS::AttachToProcess(lldb::pid_t pid) {
-  Status error;
-
   Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PROCESS));
   if (log)
     log->Printf("GDBRemoteCommunicationServerLLGS::%s pid %" PRIu64,
@@ -321,13 +316,14 @@ Status GDBRemoteCommunicationServerLLGS::AttachToProcess(lldb::pid_t pid) {
                   pid, m_debugged_process_sp->GetID());
 
   // Try to attach.
-  error = NativeProcessProtocol::Attach(pid, *this, m_mainloop,
-                                        m_debugged_process_sp);
-  if (!error.Success()) {
-    fprintf(stderr, "%s: failed to attach to process %" PRIu64 ": %s",
-            __FUNCTION__, pid, error.AsCString());
-    return error;
+  auto process_or = m_process_factory.Attach(pid, *this, m_mainloop);
+  if (!process_or) {
+    Status status(process_or.takeError());
+    llvm::errs() << llvm::formatv("failed to attach to process {0}: {1}", pid,
+                                  status);
+    return status;
   }
+  m_debugged_process_sp = *process_or;
 
   // Setup stdout/stderr mapping from inferior.
   auto terminal_fd = m_debugged_process_sp->GetTerminalFileDescriptor();
@@ -336,9 +332,9 @@ Status GDBRemoteCommunicationServerLLGS::AttachToProcess(lldb::pid_t pid) {
       log->Printf("ProcessGDBRemoteCommunicationServerLLGS::%s setting "
                   "inferior STDIO fd to %d",
                   __FUNCTION__, terminal_fd);
-    error = SetSTDIOFileDescriptor(terminal_fd);
-    if (error.Fail())
-      return error;
+    Status status = SetSTDIOFileDescriptor(terminal_fd);
+    if (status.Fail())
+      return status;
   } else {
     if (log)
       log->Printf("ProcessGDBRemoteCommunicationServerLLGS::%s ignoring "
@@ -347,8 +343,7 @@ Status GDBRemoteCommunicationServerLLGS::AttachToProcess(lldb::pid_t pid) {
   }
 
   printf("Attached to process %" PRIu64 "...\n", pid);
-
-  return error;
+  return Status();
 }
 
 void GDBRemoteCommunicationServerLLGS::InitializeDelegate(
@@ -1128,7 +1123,7 @@ GDBRemoteCommunicationServerLLGS::Handle_jTraceStart(
   uid = m_debugged_process_sp->StartTrace(options, error);
   LLDB_LOG(log, "uid is {0} , error is {1}", uid, error.GetError());
   if (error.Fail())
-    return SendErrorResponse(error.GetError());
+    return SendErrorResponse(error);
 
   StreamGDBRemote response;
   response.Printf("%" PRIx64, uid);
@@ -1165,7 +1160,7 @@ GDBRemoteCommunicationServerLLGS::Handle_jTraceStop(
   Status error = m_debugged_process_sp->StopTrace(uid, tid);
 
   if (error.Fail())
-    return SendErrorResponse(error.GetError());
+    return SendErrorResponse(error);
 
   return SendOKResponse();
 }
@@ -1208,7 +1203,7 @@ GDBRemoteCommunicationServerLLGS::Handle_jTraceConfigRead(
   Status error = m_debugged_process_sp->GetTraceConfig(uid, options);
 
   if (error.Fail())
-    return SendErrorResponse(error.GetError());
+    return SendErrorResponse(error);
 
   StreamGDBRemote escaped_response;
   StructuredData::Dictionary json_packet;
@@ -1284,7 +1279,7 @@ GDBRemoteCommunicationServerLLGS::Handle_jTraceRead(
     error = m_debugged_process_sp->GetMetaData(uid, tid, buf, offset);
 
   if (error.Fail())
-    return SendErrorResponse(error.GetError());
+    return SendErrorResponse(error);
 
   for (auto i : buf)
     response.PutHex8(i);
diff --git a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
index a7d7850d454f..b065642d4aed 100644
--- a/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
+++ b/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
@@ -39,7 +39,9 @@ public:
   //------------------------------------------------------------------
   // Constructors and Destructors
   //------------------------------------------------------------------
-  GDBRemoteCommunicationServerLLGS(MainLoop &mainloop);
+  GDBRemoteCommunicationServerLLGS(
+      MainLoop &mainloop,
+      const NativeProcessProtocol::Factory &process_factory);
 
   //------------------------------------------------------------------
   /// Specify the program to launch and its arguments.
@@ -108,20 +110,21 @@ public:
 protected:
   MainLoop &m_mainloop;
   MainLoop::ReadHandleUP m_network_handle_up;
-  lldb::tid_t m_current_tid;
-  lldb::tid_t m_continue_tid;
+  const NativeProcessProtocol::Factory &m_process_factory;
+  lldb::tid_t m_current_tid = LLDB_INVALID_THREAD_ID;
+  lldb::tid_t m_continue_tid = LLDB_INVALID_THREAD_ID;
   std::recursive_mutex m_debugged_process_mutex;
   NativeProcessProtocolSP m_debugged_process_sp;
 
   Communication m_stdio_communication;
   MainLoop::ReadHandleUP m_stdio_handle_up;
 
-  lldb::StateType m_inferior_prev_state;
+  lldb::StateType m_inferior_prev_state = lldb::StateType::eStateInvalid;
   std::unique_ptr<llvm::MemoryBuffer> m_active_auxv_buffer_up;
   std::mutex m_saved_registers_mutex;
   std::unordered_map<uint32_t, lldb::DataBufferSP> m_saved_registers_map;
-  uint32_t m_next_saved_registers_id;
-  bool m_handshake_completed : 1;
+  uint32_t m_next_saved_registers_id = 1;
+  bool m_handshake_completed = false;
 
   PacketResult SendONotification(const char *buffer, uint32_t len);
 
diff --git a/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index 042c96111bb3..8a66f3865ebc 100644
--- a/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -1031,6 +1031,7 @@ Status ProcessGDBRemote::ConnectToDebugserver(llvm::StringRef connect_url) {
   m_gdb_comm.GetHostInfo();
   m_gdb_comm.GetVContSupported('c');
   m_gdb_comm.GetVAttachOrWaitSupported();
+  m_gdb_comm.EnableErrorStringInPacket();
 
   // Ask the remote server for the default thread id
   if (GetTarget().GetNonStopModeEnabled())
diff --git a/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp b/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
index b7fbd7347d08..6c39690268c6 100644
--- a/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
+++ b/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
@@ -1857,14 +1857,12 @@ StructuredData::DictionarySP ScriptInterpreterPython::GetDynamicSettings(
     return StructuredData::DictionarySP();
 
   PythonObject reply_pyobj;
-  {
-    Locker py_lock(this,
-                   Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
-    TargetSP target_sp(target->shared_from_this());
-    reply_pyobj.Reset(PyRefType::Owned,
-                      (PyObject *)g_swig_plugin_get(generic->GetValue(),
-                                                    setting_name, target_sp));
-  }
+  Locker py_lock(this,
+                 Locker::AcquireLock | Locker::InitSession | Locker::NoSTDIN);
+  TargetSP target_sp(target->shared_from_this());
+  reply_pyobj.Reset(PyRefType::Owned,
+                    (PyObject *)g_swig_plugin_get(generic->GetValue(),
+                                                  setting_name, target_sp));
 
   PythonDictionary py_dict(PyRefType::Borrowed, reply_pyobj.get());
   return py_dict.CreateStructuredDictionary();
diff --git a/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp b/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp
index 9d79a411faad..aa15063ac0dc 100644
--- a/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp
+++ b/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.cpp
@@ -604,9 +604,10 @@ uint32_t x86AssemblyInspectionEngine::extract_4(uint8_t *b) {
 }
 
 bool x86AssemblyInspectionEngine::instruction_length(uint8_t *insn_p,
-                                                     int &length) {
+                                                     int &length, 
+                                                     uint32_t buffer_remaining_bytes) {
 
-  const uint32_t max_op_byte_size = m_arch.GetMaximumOpcodeByteSize();
+  uint32_t max_op_byte_size = std::min(buffer_remaining_bytes, m_arch.GetMaximumOpcodeByteSize());
   llvm::SmallVector<uint8_t, 32> opcode_data;
   opcode_data.resize(max_op_byte_size);
 
@@ -698,8 +699,9 @@ bool x86AssemblyInspectionEngine::GetNonCallSiteUnwindPlanFromAssembly(
     bool row_updated = false; // The UnwindPlan::Row 'row' has been updated
 
     m_cur_insn = data + current_func_text_offset;
-    if (!instruction_length(m_cur_insn, insn_len) || insn_len == 0 ||
-        insn_len > kMaxInstructionByteSize) {
+    if (!instruction_length(m_cur_insn, insn_len, size - current_func_text_offset)
+        || insn_len == 0 
+        || insn_len > kMaxInstructionByteSize) {
       // An unrecognized/junk instruction
       break;
     }
@@ -1002,8 +1004,9 @@ bool x86AssemblyInspectionEngine::AugmentUnwindPlanFromCallSite(
   while (offset < size) {
     m_cur_insn = data + offset;
     int insn_len;
-    if (!instruction_length(m_cur_insn, insn_len) || insn_len == 0 ||
-        insn_len > kMaxInstructionByteSize) {
+    if (!instruction_length(m_cur_insn, insn_len, size - offset)
+        || insn_len == 0 
+        || insn_len > kMaxInstructionByteSize) {
       // An unrecognized/junk instruction.
       break;
     }
@@ -1214,8 +1217,9 @@ bool x86AssemblyInspectionEngine::FindFirstNonPrologueInstruction(
     int scratch;
 
     m_cur_insn = data + offset;
-    if (!instruction_length(m_cur_insn, insn_len) ||
-        insn_len > kMaxInstructionByteSize || insn_len == 0) {
+    if (!instruction_length(m_cur_insn, insn_len, size - offset) 
+        || insn_len > kMaxInstructionByteSize 
+        || insn_len == 0) {
       // An error parsing the instruction, i.e. probably data/garbage - stop
       // scanning
       break;
diff --git a/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.h b/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.h
index 2e7875966cb6..97441d362973 100644
--- a/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.h
+++ b/source/Plugins/UnwindAssembly/x86/x86AssemblyInspectionEngine.h
@@ -113,7 +113,7 @@ private:
   bool ret_pattern_p();
   uint32_t extract_4(uint8_t *b);
 
-  bool instruction_length(uint8_t *insn, int &length);
+  bool instruction_length(uint8_t *insn, int &length, uint32_t buffer_remaining_bytes);
 
   bool machine_regno_to_lldb_regno(int machine_regno, uint32_t &lldb_regno);
 
diff --git a/source/Utility/StringExtractorGDBRemote.cpp b/source/Utility/StringExtractorGDBRemote.cpp
index 3473a9e96689..8e50c0106a48 100644
--- a/source/Utility/StringExtractorGDBRemote.cpp
+++ b/source/Utility/StringExtractorGDBRemote.cpp
@@ -19,8 +19,18 @@ StringExtractorGDBRemote::GetResponseType() const {
 
   switch (m_packet[0]) {
   case 'E':
-    if (m_packet.size() == 3 && isxdigit(m_packet[1]) && isxdigit(m_packet[2]))
-      return eError;
+    if (isxdigit(m_packet[1]) && isxdigit(m_packet[2])) {
+      if (m_packet.size() == 3)
+        return eError;
+      llvm::StringRef packet_ref(m_packet);
+      if (packet_ref[3] == ';') {
+        auto err_string = packet_ref.substr(4);
+        for (auto e : err_string)
+          if (!isxdigit(e))
+            return eResponse;
+        return eError;
+      }
+    }
     break;
 
   case 'O':
@@ -86,6 +96,8 @@ StringExtractorGDBRemote::GetServerPacketType() const {
         return eServerPacketType_QEnvironment;
       if (PACKET_STARTS_WITH("QEnvironmentHexEncoded:"))
         return eServerPacketType_QEnvironmentHexEncoded;
+      if (PACKET_STARTS_WITH("QEnableErrorStrings"))
+        return eServerPacketType_QEnableErrorStrings;
       break;
 
     case 'P':
@@ -438,8 +450,8 @@ bool StringExtractorGDBRemote::IsNormalResponse() const {
 }
 
 bool StringExtractorGDBRemote::IsErrorResponse() const {
-  return GetResponseType() == eError && m_packet.size() == 3 &&
-         isxdigit(m_packet[1]) && isxdigit(m_packet[2]);
+  return GetResponseType() == eError && isxdigit(m_packet[1]) &&
+         isxdigit(m_packet[2]);
 }
 
 uint8_t StringExtractorGDBRemote::GetError() {
@@ -450,6 +462,23 @@ uint8_t StringExtractorGDBRemote::GetError() {
   return 0;
 }
 
+lldb_private::Status StringExtractorGDBRemote::GetStatus() {
+  lldb_private::Status error;
+  if (GetResponseType() == eError) {
+    SetFilePos(1);
+    uint8_t errc = GetHexU8(255);
+    error.SetError(errc, lldb::eErrorTypeGeneric);
+
+    error.SetErrorStringWithFormat("Error %u", errc);
+    std::string error_messg;
+    if (GetChar() == ';') {
+      GetHexByteString(error_messg);
+      error.SetErrorString(error_messg);
+    }
+  }
+  return error;
+}
+
 size_t StringExtractorGDBRemote::GetEscapedBinaryData(std::string &str) {
   // Just get the data bytes in the string as
   // GDBRemoteCommunication::CheckForPacket()
diff --git a/source/Utility/StringExtractorGDBRemote.h b/source/Utility/StringExtractorGDBRemote.h
index 473cab04f800..f4ed642a706e 100644
--- a/source/Utility/StringExtractorGDBRemote.h
+++ b/source/Utility/StringExtractorGDBRemote.h
@@ -10,6 +10,7 @@
 #ifndef utility_StringExtractorGDBRemote_h_
 #define utility_StringExtractorGDBRemote_h_
 
+#include "lldb/Utility/Status.h"
 #include "lldb/Utility/StringExtractor.h"
 #include "llvm/ADT/StringRef.h" // for StringRef
 
@@ -72,6 +73,7 @@ public:
     eServerPacketType_qGetWorkingDir,
     eServerPacketType_qFileLoadAddress,
     eServerPacketType_QEnvironment,
+    eServerPacketType_QEnableErrorStrings,
     eServerPacketType_QLaunchArch,
     eServerPacketType_QSetDisableASLR,
     eServerPacketType_QSetDetachOnError,
@@ -190,6 +192,8 @@ public:
   // digits. Otherwise the error encoded in XX is returned.
   uint8_t GetError();
 
+  lldb_private::Status GetStatus();
+
   size_t GetEscapedBinaryData(std::string &str);
 
 protected:
diff --git a/tools/lldb-server/CMakeLists.txt b/tools/lldb-server/CMakeLists.txt
index 4f76ebd6881c..f8c57cb9488f 100644
--- a/tools/lldb-server/CMakeLists.txt
+++ b/tools/lldb-server/CMakeLists.txt
@@ -59,6 +59,16 @@ if (LLVM_BUILD_STATIC)
   endif()
 endif()
 
+set(LLDB_PLUGINS)
+
+if(CMAKE_SYSTEM_NAME MATCHES "Linux|Android")
+  list(APPEND LLDB_PLUGINS lldbPluginProcessLinux)
+endif()
+
+if(CMAKE_SYSTEM_NAME MATCHES "NetBSD")
+  list(APPEND LLDB_PLUGINS lldbPluginProcessNetBSD)
+endif()
+
 add_lldb_tool(lldb-server INCLUDE_IN_FRAMEWORK
     Acceptor.cpp
     lldb-gdbserver.cpp
@@ -72,7 +82,7 @@ add_lldb_tool(lldb-server INCLUDE_IN_FRAMEWORK
       lldbHost
       lldbInitialization
       lldbInterpreter
-      ${EXTRA_LLDB_LIBS}
+      ${LLDB_PLUGINS}
       ${LLDB_SYSTEM_LIBS}
 
     LINK_COMPONENTS
diff --git a/tools/lldb-server/lldb-gdbserver.cpp b/tools/lldb-server/lldb-gdbserver.cpp
index 412d775e8394..337f244c2c2d 100644
--- a/tools/lldb-server/lldb-gdbserver.cpp
+++ b/tools/lldb-server/lldb-gdbserver.cpp
@@ -33,10 +33,17 @@
 #include "lldb/Host/Pipe.h"
 #include "lldb/Host/Socket.h"
 #include "lldb/Host/StringConvert.h"
+#include "lldb/Host/common/NativeProcessProtocol.h"
 #include "lldb/Utility/Status.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Errno.h"
 
+#if defined(__linux__)
+#include "Plugins/Process/Linux/NativeProcessLinux.h"
+#elif defined(__NetBSD__)
+#include "Plugins/Process/NetBSD/NativeProcessNetBSD.h"
+#endif
+
 #ifndef LLGS_PROGRAM_NAME
 #define LLGS_PROGRAM_NAME "lldb-server"
 #endif
@@ -51,6 +58,30 @@ using namespace lldb_private;
 using namespace lldb_private::lldb_server;
 using namespace lldb_private::process_gdb_remote;
 
+namespace {
+#if defined(__linux__)
+typedef process_linux::NativeProcessLinux::Factory NativeProcessFactory;
+#elif defined(__NetBSD__)
+typedef process_netbsd::NativeProcessNetBSD::Factory NativeProcessFactory;
+#else
+// Dummy implementation to make sure the code compiles
+class NativeProcessFactory : public NativeProcessProtocol::Factory {
+public:
+  llvm::Expected<NativeProcessProtocolSP>
+  Launch(ProcessLaunchInfo &launch_info,
+         NativeProcessProtocol::NativeDelegate &delegate,
+         MainLoop &mainloop) const override {
+    llvm_unreachable("Not implemented");
+  }
+  llvm::Expected<NativeProcessProtocolSP>
+  Attach(lldb::pid_t pid, NativeProcessProtocol::NativeDelegate &delegate,
+         MainLoop &mainloop) const override {
+    llvm_unreachable("Not implemented");
+  }
+};
+#endif
+}
+
 //----------------------------------------------------------------------
 // option descriptors for getopt_long_only()
 //----------------------------------------------------------------------
@@ -446,7 +477,8 @@ int main_gdbserver(int argc, char *argv[]) {
     exit(255);
   }
 
-  GDBRemoteCommunicationServerLLGS gdb_server(mainloop);
+  NativeProcessFactory factory;
+  GDBRemoteCommunicationServerLLGS gdb_server(mainloop, factory);
 
   const char *const host_and_port = argv[0];
   argc -= 1;
diff --git a/tools/lldb-server/lldb-platform.cpp b/tools/lldb-server/lldb-platform.cpp
index 8d45682566b9..ec5b781dac48 100644
--- a/tools/lldb-server/lldb-platform.cpp
+++ b/tools/lldb-server/lldb-platform.cpp
@@ -197,46 +197,41 @@ int main_platform(int argc, char *argv[]) {
       break;
 
     case 'p': {
-      char *end = NULL;
-      long tmp_port_offset = strtoul(optarg, &end, 0);
-      if (end && *end == '\0') {
-        if (LOW_PORT <= tmp_port_offset && tmp_port_offset <= HIGH_PORT) {
-          port_offset = (uint16_t)tmp_port_offset;
-        } else {
-          fprintf(stderr, "error: port offset %li is not in the valid user "
-                          "port range of %u - %u\n",
-                  tmp_port_offset, LOW_PORT, HIGH_PORT);
-          option_error = 5;
-        }
-      } else {
-        fprintf(stderr, "error: invalid port offset string %s\n", optarg);
+      if (!llvm::to_integer(optarg, port_offset)) {
+        llvm::errs() << "error: invalid port offset string " << optarg << "\n";
         option_error = 4;
+        break;
+      }
+      if (port_offset < LOW_PORT || port_offset > HIGH_PORT) {
+        llvm::errs() << llvm::formatv("error: port offset {0} is not in the "
+                                      "valid user port range of {1} - {2}\n",
+                                      port_offset, LOW_PORT, HIGH_PORT);
+        option_error = 5;
       }
     } break;
 
     case 'P':
     case 'm':
     case 'M': {
-      char *end = NULL;
-      long portnum = strtoul(optarg, &end, 0);
-      if (end && *end == '\0') {
-        if (LOW_PORT <= portnum && portnum <= HIGH_PORT) {
-          if (ch == 'P')
-            gdbserver_portmap[(uint16_t)portnum] = LLDB_INVALID_PROCESS_ID;
-          else if (ch == 'm')
-            min_gdbserver_port = portnum;
-          else
-            max_gdbserver_port = portnum;
-        } else {
-          fprintf(stderr, "error: port number %li is not in the valid user "
-                          "port range of %u - %u\n",
-                  portnum, LOW_PORT, HIGH_PORT);
-          option_error = 1;
-        }
-      } else {
-        fprintf(stderr, "error: invalid port number string %s\n", optarg);
+      uint16_t portnum;
+      if (!llvm::to_integer(optarg, portnum)) {
+        llvm::errs() << "error: invalid port number string " << optarg << "\n";
         option_error = 2;
+        break;
+      }
+      if (portnum < LOW_PORT || portnum > HIGH_PORT) {
+        llvm::errs() << llvm::formatv("error: port number {0} is not in the "
+                                      "valid user port range of {1} - {2}\n",
+                                      portnum, LOW_PORT, HIGH_PORT);
+        option_error = 1;
+        break;
       }
+      if (ch == 'P')
+        gdbserver_portmap[portnum] = LLDB_INVALID_PROCESS_ID;
+      else if (ch == 'm')
+        min_gdbserver_port = portnum;
+      else
+        max_gdbserver_port = portnum;
     } break;
 
     case 'h': /* fall-through is intentional */
diff --git a/unittests/Process/Linux/ProcessorTraceTest.cpp b/unittests/Process/Linux/ProcessorTraceTest.cpp
index b732934d014d..67381b6ddca3 100644
--- a/unittests/Process/Linux/ProcessorTraceTest.cpp
+++ b/unittests/Process/Linux/ProcessorTraceTest.cpp
@@ -30,42 +30,40 @@ size_t ReadCylicBufferWrapper(void *buf, size_t buf_size, void *cyc_buf,
 }
 
 TEST(CyclicBuffer, EdgeCases) {
-  size_t bytes_read = 0;
+  size_t bytes_read;
   uint8_t cyclic_buffer[6] = {'l', 'i', 'c', 'c', 'y', 'c'};
 
   // We will always leave the last bytes untouched
   // so that string comparisions work.
-  char bigger_buffer[10] = {};
-  char equal_size_buffer[7] = {};
   char smaller_buffer[4] = {};
 
   // empty buffer to read into
   bytes_read = ReadCylicBufferWrapper(smaller_buffer, 0, cyclic_buffer,
                                       sizeof(cyclic_buffer), 3, 0);
-  ASSERT_EQ(0, bytes_read);
+  ASSERT_EQ(0u, bytes_read);
 
   // empty cyclic buffer
   bytes_read = ReadCylicBufferWrapper(smaller_buffer, sizeof(smaller_buffer),
                                       cyclic_buffer, 0, 3, 0);
-  ASSERT_EQ(0, bytes_read);
+  ASSERT_EQ(0u, bytes_read);
 
   // bigger offset
   bytes_read =
       ReadCylicBufferWrapper(smaller_buffer, sizeof(smaller_buffer),
                              cyclic_buffer, sizeof(cyclic_buffer), 3, 6);
-  ASSERT_EQ(0, bytes_read);
+  ASSERT_EQ(0u, bytes_read);
 
   // wrong offset
   bytes_read =
       ReadCylicBufferWrapper(smaller_buffer, sizeof(smaller_buffer),
                              cyclic_buffer, sizeof(cyclic_buffer), 3, 7);
-  ASSERT_EQ(0, bytes_read);
+  ASSERT_EQ(0u, bytes_read);
 
   // wrong start
   bytes_read =
       ReadCylicBufferWrapper(smaller_buffer, sizeof(smaller_buffer),
                              cyclic_buffer, sizeof(cyclic_buffer), 3, 7);
-  ASSERT_EQ(0, bytes_read);
+  ASSERT_EQ(0u, bytes_read);
 }
 
 TEST(CyclicBuffer, EqualSizeBuffer) {
@@ -73,7 +71,7 @@ TEST(CyclicBuffer, EqualSizeBuffer) {
   uint8_t cyclic_buffer[6] = {'l', 'i', 'c', 'c', 'y', 'c'};
 
   char cyclic[] = "cyclic";
-  for (int i = 0; i < sizeof(cyclic); i++) {
+  for (size_t i = 0; i < sizeof(cyclic); i++) {
     // We will always leave the last bytes untouched
     // so that string comparisions work.
     char equal_size_buffer[7] = {};
@@ -86,7 +84,7 @@ TEST(CyclicBuffer, EqualSizeBuffer) {
 }
 
 TEST(CyclicBuffer, SmallerSizeBuffer) {
-  size_t bytes_read = 0;
+  size_t bytes_read;
   uint8_t cyclic_buffer[6] = {'l', 'i', 'c', 'c', 'y', 'c'};
 
   // We will always leave the last bytes untouched
@@ -95,25 +93,25 @@ TEST(CyclicBuffer, SmallerSizeBuffer) {
   bytes_read =
       ReadCylicBufferWrapper(smaller_buffer, (sizeof(smaller_buffer) - 1),
                              cyclic_buffer, sizeof(cyclic_buffer), 3, 0);
-  ASSERT_EQ(3, bytes_read);
+  ASSERT_EQ(3u, bytes_read);
   ASSERT_STREQ(smaller_buffer, "cyc");
 
   bytes_read =
       ReadCylicBufferWrapper(smaller_buffer, (sizeof(smaller_buffer) - 1),
                              cyclic_buffer, sizeof(cyclic_buffer), 3, 1);
-  ASSERT_EQ(3, bytes_read);
+  ASSERT_EQ(3u, bytes_read);
   ASSERT_STREQ(smaller_buffer, "ycl");
 
   bytes_read =
       ReadCylicBufferWrapper(smaller_buffer, (sizeof(smaller_buffer) - 1),
                              cyclic_buffer, sizeof(cyclic_buffer), 3, 2);
-  ASSERT_EQ(3, bytes_read);
+  ASSERT_EQ(3u, bytes_read);
   ASSERT_STREQ(smaller_buffer, "cli");
 
   bytes_read =
       ReadCylicBufferWrapper(smaller_buffer, (sizeof(smaller_buffer) - 1),
                              cyclic_buffer, sizeof(cyclic_buffer), 3, 3);
-  ASSERT_EQ(3, bytes_read);
+  ASSERT_EQ(3u, bytes_read);
   ASSERT_STREQ(smaller_buffer, "lic");
 
   {
@@ -121,7 +119,7 @@ TEST(CyclicBuffer, SmallerSizeBuffer) {
     bytes_read =
         ReadCylicBufferWrapper(smaller_buffer, (sizeof(smaller_buffer) - 1),
                                cyclic_buffer, sizeof(cyclic_buffer), 3, 4);
-    ASSERT_EQ(2, bytes_read);
+    ASSERT_EQ(2u, bytes_read);
     ASSERT_STREQ(smaller_buffer, "ic");
   }
   {
@@ -129,7 +127,7 @@ TEST(CyclicBuffer, SmallerSizeBuffer) {
     bytes_read =
         ReadCylicBufferWrapper(smaller_buffer, (sizeof(smaller_buffer) - 1),
                                cyclic_buffer, sizeof(cyclic_buffer), 3, 5);
-    ASSERT_EQ(1, bytes_read);
+    ASSERT_EQ(1u, bytes_read);
     ASSERT_STREQ(smaller_buffer, "c");
   }
 }
@@ -139,7 +137,7 @@ TEST(CyclicBuffer, BiggerSizeBuffer) {
   uint8_t cyclic_buffer[6] = {'l', 'i', 'c', 'c', 'y', 'c'};
 
   char cyclic[] = "cyclic";
-  for (int i = 0; i < sizeof(cyclic); i++) {
+  for (size_t i = 0; i < sizeof(cyclic); i++) {
     // We will always leave the last bytes untouched
     // so that string comparisions work.
     char bigger_buffer[10] = {};
diff --git a/unittests/UnwindAssembly/x86/Testx86AssemblyInspectionEngine.cpp b/unittests/UnwindAssembly/x86/Testx86AssemblyInspectionEngine.cpp
index e97760967197..c3591b2d73e1 100644
--- a/unittests/UnwindAssembly/x86/Testx86AssemblyInspectionEngine.cpp
+++ b/unittests/UnwindAssembly/x86/Testx86AssemblyInspectionEngine.cpp
@@ -2415,3 +2415,28 @@ TEST_F(Testx86AssemblyInspectionEngine, TestStackRealign32BitDisp_x86_64) {
   EXPECT_EQ(rsp_plus_8,
             plan.GetRowForFunctionOffset(sizeof(data) - 1)->GetCFAValue());
 }
+
+// Give the disassembler random bytes to test that it doesn't exceed
+// the bounds of the array when run under clang's address sanitizer.
+TEST_F(Testx86AssemblyInspectionEngine, TestDisassemblyJunkBytes) {
+  AddressRange sample_range;
+  UnwindPlan unwind_plan(eRegisterKindLLDB);
+  std::unique_ptr<x86AssemblyInspectionEngine> engine32 = Geti386Inspector();
+  std::unique_ptr<x86AssemblyInspectionEngine> engine64 = Getx86_64Inspector();
+
+  uint8_t data[] = {
+      0x10, 0x10, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+      0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0 };
+
+  sample_range = AddressRange(0x1000, sizeof(data));
+
+  EXPECT_TRUE(engine32->GetNonCallSiteUnwindPlanFromAssembly(
+      data, sizeof(data), sample_range, unwind_plan));
+
+  unwind_plan.Clear();
+
+  EXPECT_TRUE(engine64->GetNonCallSiteUnwindPlanFromAssembly(
+      data, sizeof(data), sample_range, unwind_plan));
+
+}
+
diff --git a/www/architecture.html b/www/architecture.html
deleted file mode 100755
index eb178febde54..000000000000
--- a/www/architecture.html
+++ /dev/null
@@ -1,294 +0,0 @@
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-<html xmlns="http://www.w3.org/1999/xhtml">
-<head>
-<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
-<link href="style.css" rel="stylesheet" type="text/css" />
-<title>LLDB Architecture</title>
-</head>
-
-<body>
-    <div class="www_title">
-      The <strong>LLDB</strong> Debugger
-    </div>
-
-<div id="container">
-	<div id="content">
-        
-  <!--#include virtual="sidebar.incl"-->
-  
-		<div id="middle">
-			<div class="post">
-				<h1 class ="postheader">Architecture</h1>
-				<div class="postcontent">
-
-				   <p>LLDB is a large and complex codebase. This section will help you become more familiar with
-				       the pieces that make up LLDB and give a general overview of the general architecture.</p>
-				</div>
-				<div class="postfooter"></div>
-			</div>
-			<div class="post">
-				<h1 class ="postheader">Code Layout</h1>
-				<div class="postcontent">
-
-				   <p>LLDB has many code groupings that makeup the source base:</p>
-                   <ul>
-     					<li><a href="#api">API</a></li>
-      					<li><a href="#breakpoint">Breakpoint</a></li>
-      					<li><a href="#commands">Commands</a></li>
-      					<li><a href="#core">Core</a></li>
-      					<li><a href="#dataformatters">DataFormatters</a></li>
-       					<li><a href="#expression">Expression</a></li>
-       					<li><a href="#host">Host</a></li>
-       					<li><a href="#interpreter">Interpreter</a></li>
-       					<li><a href="#symbol">Symbol</a></li>
-       					<li><a href="#targ">Target</a></li>
-       					<li><a href="#utility">Utility</a></li>
-   				    </ul>
-				</div>
-				<div class="postfooter"></div>
-			</div>
-			<a name="api"></a>
-			<div class="post">
-				<h1 class ="postheader">API</h1>
-				<div class="postcontent">
-
-				   <p>The API folder contains the public interface to LLDB.</p>
-                   <p>We are currently vending a C++ API. In order to be able to add
-  				        methods to this API and allow people to link to our classes,
-  				        we have certain rules that we must follow:</p>
-                   <ul>
-     					<li>Classes can't inherit from any other classes.</li>
-      					<li>Classes can't contain virtual methods.</li>
-       					<li>Classes should be compatible with script bridging utilities like <a href="http://www.swig.org/">swig</a>.</li>
-       					<li>Classes should be lightweight and be backed by a single member. Pointers (or shared pointers) are the preferred choice since they allow changing the contents of the backend without affecting the public object layout.</li>
-       					<li>The interface should be as minimal as possible in order to give a complete API.</li>
-   				    </ul>
-   				    <p>By adhering to these rules we should be able to continue to 
-   				        vend a C++ API, and make changes to the API as any additional
-   				        methods added to these classes will just be a dynamic loader
-   				        lookup and they won't affect the class layout (since they
-   				        aren't virtual methods, and no members can be added to the
-   				        class).</p>
-				</div>
-				<div class="postfooter"></div>
-			</div>
-			<a name="breakpoint"></a>
-			<div class="post">
-				<h1 class ="postheader">Breakpoint</h1>
-				<div class="postcontent">
-
-				   <p>A collection of classes that implement our breakpoint classes. 
-				       Breakpoints are resolved symbolically and always continue to
-				       resolve themselves as your program runs. Whether settings breakpoints
-				       by file and line, by symbol name, by symbol regular expression,
-				       or by address, breakpoints will keep trying to resolve new locations
-				       each time shared libraries are loaded. Breakpoints will of course
-				       unresolve themselves when shared libraries are unloaded. Breakpoints
-				       can also be scoped to be set only in a specific shared library. By
-				       default, breakpoints can be set in any shared library and will continue
-				       to attempt to be resolved with each shared library load.</p>
-                   <p>Breakpoint options can be set on the breakpoint,
-                       or on the individual locations. This allows flexibility when dealing
-                       with breakpoints and allows us to do what the user wants.</p>
-				</div>
-				<div class="postfooter"></div>
-			</div>
-			<a name="commands"></a>
-			<div class="post">
-				<h1 class ="postheader">Commands</h1>
-				<div class="postcontent">
-
-				   <p>The command source files represent objects that implement
-				       the functionality for all textual commands available 
-				       in our command line interface.</p>
-                   <p>Every command is backed by a <b>lldb_private::CommandObject</b>
-                       or <b>lldb_private::CommandObjectMultiword</b> object.</p>
-                   <p><b>lldb_private::CommandObjectMultiword</b> are commands that
-                      have subcommands and allow command line commands to be
-                      logically grouped into a hierarchy.</p>
-                  <p><b>lldb_private::CommandObject</b> command line commands
-                      are the objects that implement the functionality of the
-                      command. They can optionally define
-                     options for themselves, as well as group those options into
-                     logical groups that can go together. The help system is
-                     tied into these objects and can extract the syntax and
-                     option groupings to display appropriate help for each
-                     command.</p>
-				</div>
-				<div class="postfooter"></div>
-			</div>
-			<a name="core"></a>
-			<div class="post">
-				<h1 class ="postheader">Core</h1>
-				<div class="postcontent">
-
-				   <p>The Core source files contain basic functionality that
-				       is required in the debugger. A wide variety of classes
-				       are implemented:</p>
-				       
-                       <ul>
-         					<li>Address (section offset addressing)</li>
-          					<li>AddressRange</li>
-           					<li>Architecture specification</li>
-           					<li>Broadcaster / Event / Listener </li>
-           					<li>Communication classes that use Connection objects</li>
-           					<li>Uniqued C strings</li>
-           					<li>Data extraction</li>
-           					<li>File specifications</li>
-           					<li>Mangled names</li>
-           					<li>Regular expressions</li>
-           					<li>Source manager</li>
-           					<li>Streams</li>
-           					<li>Value objects</li>
-       				    </ul>
-				</div>
-				<div class="postfooter"></div>
-			</div>
-			<a name="dataformatters"></a>
-			<div class="post">
-				<h1 class ="postheader">DataFormatters</h1>
-				<div class="postcontent">
-
-				   <p>A collection of classes that implement the data formatters subsystem.</p>
-				
-				<p>For a general user-level introduction to data formatters, you can look <a href="varformats.html">here</a>.
-				<p>A 10,000 foot view of the data formatters is based upon the <code>DataVisualization</code> class.
-					<code>DataVisualization</code> is the very high level entry point into the data formatters. It vends a stable interface in face of changing internals
-					and is the recommended entry point for components of LLDB that need to ask questions of the data formatters.
-					The main questions one can ask of <code>DataVisualization</code> are:
-					<ul>
-						<li>given a ValueObject, retrieve the formatters to be used for it</li>
-						<li>given a type, retrieve the formatters to be used for it. This is not an "exact" question,
-							i.e. one can retrieve a formatter from a type name which would not be used to then format ValueObjects of that type</li>
-						<li>given a name, retrieve a category of that name, optionally creating it if needed - more generally, categories management</li>
-						<li>given an identifier and a summary, store it as a named summary - more generally, named summary management</li>
-					</ul>
-					
-				<p>For people actively maintaining the data formatters subsystem itself, however, the FormatManager class is the relevant point of entry.
-					This class is subject to more frequent changes as the formatters evolve. Currently, it provides a thin caching layer on top of a list of categories
-					that each export a group of formatters.
-					</p>
-				<p>From an end-user perspective, the "type" LLDB command is the point of access to the data formatters. A large group of generally-useful formatters
-					is provided by default and loaded upon debugger startup.
-				</div>
-				<div class="postfooter"></div>
-			</div>
-			<a name="expression"></a>
-			<div class="post">
-				<h1 class ="postheader">Expression</h1>
-				<div class="postcontent">
-
-				   <p>Expression parsing files cover everything from evaluating
-				       DWARF expressions, to evaluating expressions using
-				       Clang.</p>
-				   <p>The DWARF expression parser has been heavily modified to
-				       support type promotion, new opcodes needed for evaluating
-				       expressions with symbolic variable references (expression local variables,
-				       program variables), and other operators required by
-				       typical expressions such as assign, address of, float/double/long 
-				       double floating point values, casting, and more. The
-				       DWARF expression parser uses a stack of lldb_private::Value
-				       objects. These objects know how to do the standard C type
-				       promotion, and allow for symbolic references to variables
-				       in the program and in the LLDB process (expression local
-				       and expression global variables).</p>
-				    <p>The expression parser uses a full instance of the Clang
-				        compiler in order to accurately evaluate expressions.
-				        Hooks have been put into Clang so that the compiler knows
-				        to ask about identifiers it doesn't know about. Once
-				        expressions have be compiled into an AST, we can then
-				        traverse this AST and either generate a DWARF expression
-				        that contains simple opcodes that can be quickly re-evaluated
-				        each time an expression needs to be evaluated, or JIT'ed
-				        up into code that can be run on the process being debugged.</p>
-				</div>
-				<div class="postfooter"></div>
-			</div>
-			<a name="host"></a>
-			<div class="post">
-				<h1 class ="postheader">Host</h1>
-				<div class="postcontent">
-
-				   <p>LLDB tries to abstract itself from the host upon which
-				       it is currently running by providing a host abstraction
-				       layer.  This layer involves everything from spawning, detaching,
-				       joining and killing native in-process threads, to getting
-				       current information about the current host.</p>
-    				   <p>Host functionality includes abstraction layers for:</p>
-                           <ul>
-             					<li>Mutexes</li>
-              					<li>Conditions</li>
-               					<li>Timing functions</li>
-               					<li>Thread functions</li>
-               					<li>Host target triple</li>
-               					<li>Host child process notifications</li>
-               					<li>Host specific types</li>
-           				    </ul>
-				</div>
-				<div class="postfooter"></div>
-			</div>
-			<a name="interpreter"></a>
-			<div class="post">
-				<h1 class ="postheader">Interpreter</h1>
-				<div class="postcontent">
-
-				   <p>The interpreter classes are the classes responsible for
-				       being the base classes needed for each command object,
-				       and is responsible for tracking and running command line
-				       commands.</p>
-				</div>
-				<div class="postfooter"></div>
-			</div>
-			<a name="symbol"></a>
-			<div class="post">
-				<h1 class ="postheader">Symbol</h1>
-				<div class="postcontent">
-				   <p>Symbol classes involve everything needed in order to parse
-				       object files and debug symbols. All the needed classes
-				       for compilation units (code and debug info for a source file),
-				       functions, lexical blocks within functions, inlined
-				       functions, types, declaration locations, and variables
-				       are in this section.</p>
-				</div>
-				<div class="postfooter"></div>
-			</div>
-			<a name="targ"></a>
-			<div class="post">
-				<h1 class ="postheader">Target</h1>
-				<div class="postcontent">
-
-				   <p>Classes that are related to a debug target include:</p>
-                       <ul>
-       					   <li>Target</li>
-        					<li>Process</li>
-         					<li>Thread</li>
-          					<li>Stack frames</li>
-          					<li>Stack frame registers</li>
-           					<li>ABI for function calling in process being debugged</li>
-           					<li>Execution context batons</li>
-       				    </ul>
-				</div>
-				<div class="postfooter"></div>
-			</div>
-			<a name="utility"></a>
-			<div class="post">
-				<h1 class ="postheader">Utility</h1>
-				<div class="postcontent">
-
-				   <p>Utility files should be as stand alone as possible and
-				       available for LLDB, plug-ins or related 
-				       applications to use.</p>
-    				   <p>Files found in the Utility section include:</p>
-                           <ul>
-           					   <li>Pseudo-terminal support</li>
-            					<li>Register numbering for specific architectures.</li>
-             					<li>String data extractors</li>
-           				    </ul>
-				</div>
-				<div class="postfooter"></div>
-			</div>
-		</div>
-	</div>
-</div>
-</body>
-</html>
diff --git a/www/architecture/index.html b/www/architecture/index.html
index fd75603f6405..312476fe6edf 100755
--- a/www/architecture/index.html
+++ b/www/architecture/index.html
@@ -119,30 +119,26 @@
 			</div>
 			<a name="core"></a>
 			<div class="post">
-				<h1 class ="postheader">Core</h1>
-				<div class="postcontent">
-
-				   <p>The Core source files contain basic functionality that
-				       is required in the debugger. A wide variety of classes
-				       are implemented:</p>
-				       
-                       <ul>
-         					<li>Address (section offset addressing)</li>
-          					<li>AddressRange</li>
-           					<li>Architecture specification</li>
-           					<li>Broadcaster / Event / Listener </li>
-           					<li>Communication classes that use Connection objects</li>
-           					<li>Uniqued C strings</li>
-           					<li>Data extraction</li>
-           					<li>File specifications</li>
-           					<li>Mangled names</li>
-           					<li>Regular expressions</li>
-           					<li>Source manager</li>
-           					<li>Streams</li>
-           					<li>Value objects</li>
-       				    </ul>
-				</div>
-				<div class="postfooter"></div>
+			  <h1 class ="postheader">Core</h1>
+			  <div class="postcontent">
+			    <p>
+			    The Core source files contain basic functionality
+			    that is required in the debugger as well as the
+			    class represeting the debugger it self (Debugger). A
+			    wide variety of classes are implemented:
+			    </p>
+			    <ul>
+			      <li>Address (section offset addressing)</li>
+			      <li>AddressRange</li>
+			      <li>Architecture specification</li>
+			      <li>Broadcaster / Event / Listener </li>
+			      <li>Communication classes that use Connection objects</li>
+			      <li>Mangled names</li>
+			      <li>Source manager</li>
+			      <li>Value objects</li>
+			    </ul>
+			  </div>
+			  <div class="postfooter"></div>
 			</div>
 			<a name="dataformatters"></a>
 			<div class="post">
@@ -193,26 +189,27 @@
 			</div>
 			<a name="host"></a>
 			<div class="post">
-				<h1 class ="postheader">Host</h1>
-				<div class="postcontent">
-
-				   <p>LLDB tries to abstract itself from the host upon which
-				       it is currently running by providing a host abstraction
-				       layer.  This layer involves everything from spawning, detaching,
-				       joining and killing native in-process threads, to getting
-				       current information about the current host.</p>
-    				   <p>Host functionality includes abstraction layers for:</p>
-                           <ul>
-             					<li>Mutexes</li>
-              					<li>Conditions</li>
-               					<li>Timing functions</li>
-               					<li>Thread functions</li>
-               					<li>Host target triple</li>
-               					<li>Host child process notifications</li>
-               					<li>Host specific types</li>
-           				    </ul>
-				</div>
-				<div class="postfooter"></div>
+			  <h1 class ="postheader">Host</h1>
+			  <div class="postcontent">
+			    <p>
+			    LLDB tries to abstract itself from the host upon which
+			    it is currently running by providing a host abstraction
+			    layer. This layer includes functionality, whose
+			    implementation varies wildly from host to host.
+			    </p>
+			    <p>Host functionality includes abstraction layers for:</p>
+			    <ul>
+			      <li>Information about the host system (triple, list of running processes, etc.)</li>
+			      <li>Launching processes</li>
+			      <li>Various OS primitives like pipes and sockets</li>
+			    </ul>
+			    <p>
+			    It also includes the base classes of the
+			    NativeProcess/Thread hierarchy, which is used by
+			    lldb-server.
+			    </p>
+			  </div>
+			  <div class="postfooter"></div>
 			</div>
 			<a name="interpreter"></a>
 			<div class="post">
@@ -259,20 +256,40 @@
 			</div>
 			<a name="utility"></a>
 			<div class="post">
-				<h1 class ="postheader">Utility</h1>
-				<div class="postcontent">
-
-				   <p>Utility files should be as stand alone as possible and
-				       available for LLDB, plug-ins or related 
-				       applications to use.</p>
-    				   <p>Files found in the Utility section include:</p>
-                           <ul>
-           					   <li>Pseudo-terminal support</li>
-            					<li>Register numbering for specific architectures.</li>
-             					<li>String data extractors</li>
-           				    </ul>
-				</div>
-				<div class="postfooter"></div>
+			  <h1 class ="postheader">Utility</h1>
+			  <div class="postcontent">
+			    <p>
+			    This module contains the lowest layers of LLDB. A
+			    lot of these classes don't really have anything to
+			    do with debugging -- they are just there because the
+			    higher layers of the debugger use these clasess
+			    to implement their functionality. Others are data
+			    structures used in many other parts of the debugger
+			    (TraceOptions). Most of the functionality in this
+			    module could be useful in an application that is
+			    <strong>not</strong> a debugger; however, providing
+			    a general purpose C++ library is an explicit
+			    non-goal of this module.
+			    </p>
+			    <p>
+			    This module provides following functionality:
+			    </p>
+			    <ul>
+			      <li>Abstract path manipulation (FileSpec)</li>
+			      <li>Data buffers (DataBuffer, DataEncoder, DataExtractor)</li>
+			      <li>Logging</li>
+			      <li>Structured data manipulation (JSON)</li>
+			      <li>Streams</li>
+			      <li>Timers</li>
+			      <li>etc.</li>
+			    </ul>
+			    <p>
+			    For historic reasons, some of this functionality
+			    overlaps that which is provided by the LLVM support
+			    library.
+			    </p>
+			  </div>
+			  <div class="postfooter"></div>
 			</div>
 		</div>
 	</div>
diff --git a/www/sidebar.incl b/www/sidebar.incl
index 184a022790e2..8c5cca373653 100644
--- a/www/sidebar.incl
+++ b/www/sidebar.incl
@@ -49,7 +49,7 @@
       <li><a href="/build.html">Build</a></li>
       <li><a href="/test.html">Test</a></li>
       <li><a href="/SB-api-coding-rules.html">SB API Coding Rules</a></li>
-      <li><a href="http://llvm.org/bugs">Bug Reports</a></li>
+      <li><a href="http://bugs.llvm.org">Bug Reports</a></li>
       <li><a href="http://llvm.org/svn/llvm-project/lldb/trunk">Browse SVN</a></li>
       <li><a href="http://llvm.org/viewvc/llvm-project/lldb/trunk">Browse ViewVC</a></li>
     </ul>