Vendor import of clang release_30 branch r142614:vendor/clang/clang-r142614

http://llvm.org/svn/llvm-project/cfe/branches/release_30@142614

4 files changed, 84 insertions, 107 deletions

diff --git a/tools/driver/Makefile b/tools/driver/Makefile
index 1ba8bc24d1fb..6b34a991bf18 100644
--- a/tools/driver/Makefile
+++ b/tools/driver/Makefile
@@ -9,13 +9,7 @@
 CLANG_LEVEL := ../..
 
 TOOLNAME = clang
-ifndef CLANG_IS_PRODUCTION
 TOOLALIAS = clang++
-else
-  ifdef CLANGXX_IS_PRODUCTION
-    TOOLALIAS = clang++
-  endif
-endif
 
 # We don't currently expect production Clang builds to be interested in
 # plugins. This is important for startup performance.
@@ -73,6 +67,3 @@ endif
 ifdef CLANG_IS_PRODUCTION
 CPP.Defines += -DCLANG_IS_PRODUCTION
 endif
-ifdef CLANGXX_IS_PRODUCTION
-CPP.Defines += -DCLANGXX_IS_PRODUCTION
-endif
diff --git a/tools/driver/cc1_main.cpp b/tools/driver/cc1_main.cpp
index 9ad4af1436ca..27f79b7e6677 100644
--- a/tools/driver/cc1_main.cpp
+++ b/tools/driver/cc1_main.cpp
@@ -27,9 +27,9 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/TargetSelect.h"
 #include "llvm/Support/Timer.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/Target/TargetSelect.h"
 #include <cstdio>
 using namespace clang;
 
@@ -38,7 +38,7 @@ using namespace clang;
 //===----------------------------------------------------------------------===//
 
 static void LLVMErrorHandler(void *UserData, const std::string &Message) {
-  Diagnostic &Diags = *static_cast<Diagnostic*>(UserData);
+  DiagnosticsEngine &Diags = *static_cast<DiagnosticsEngine*>(UserData);
 
   Diags.Report(diag::err_fe_error_backend) << Message;
 
@@ -47,7 +47,7 @@ static void LLVMErrorHandler(void *UserData, const std::string &Message) {
 }
 
 // FIXME: Define the need for this testing away.
-static int cc1_test(Diagnostic &Diags,
+static int cc1_test(DiagnosticsEngine &Diags,
                     const char **ArgBegin, const char **ArgEnd) {
   using namespace clang::driver;
 
@@ -83,7 +83,7 @@ static int cc1_test(Diagnostic &Diags,
   Invocation.toArgs(InvocationArgs);
 
   // Dump the converted arguments.
-  llvm::SmallVector<const char*, 32> Invocation2Args;
+  SmallVector<const char*, 32> Invocation2Args;
   llvm::errs() << "invocation argv :";
   for (unsigned i = 0, e = InvocationArgs.size(); i != e; ++i) {
     Invocation2Args.push_back(InvocationArgs[i].c_str());
@@ -118,23 +118,22 @@ int cc1_main(const char **ArgBegin, const char **ArgEnd,
   llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
 
   // Run clang -cc1 test.
-  if (ArgBegin != ArgEnd && llvm::StringRef(ArgBegin[0]) == "-cc1test") {
-    Diagnostic Diags(DiagID, new TextDiagnosticPrinter(llvm::errs(), 
+  if (ArgBegin != ArgEnd && StringRef(ArgBegin[0]) == "-cc1test") {
+    DiagnosticsEngine Diags(DiagID, new TextDiagnosticPrinter(llvm::errs(), 
                                                        DiagnosticOptions()));
     return cc1_test(Diags, ArgBegin + 1, ArgEnd);
   }
 
   // Initialize targets first, so that --version shows registered targets.
   llvm::InitializeAllTargets();
-  llvm::InitializeAllMCAsmInfos();
-  llvm::InitializeAllMCSubtargetInfos();
+  llvm::InitializeAllTargetMCs();
   llvm::InitializeAllAsmPrinters();
   llvm::InitializeAllAsmParsers();
 
   // Buffer diagnostics from argument parsing so that we can output them using a
   // well formed diagnostic object.
   TextDiagnosticBuffer *DiagsBuffer = new TextDiagnosticBuffer;
-  Diagnostic Diags(DiagID, DiagsBuffer);
+  DiagnosticsEngine Diags(DiagID, DiagsBuffer);
   CompilerInvocation::CreateFromArgs(Clang->getInvocation(), ArgBegin, ArgEnd,
                                      Diags);
 
diff --git a/tools/driver/cc1as_main.cpp b/tools/driver/cc1as_main.cpp
index 358d746986c8..7cc42aa62768 100644
--- a/tools/driver/cc1as_main.cpp
+++ b/tools/driver/cc1as_main.cpp
@@ -30,8 +30,12 @@
 #include "llvm/MC/MCCodeEmitter.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCObjectFileInfo.h"
+#include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/MC/MCAsmBackend.h"
+#include "llvm/MC/MCTargetAsmParser.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FormattedStream.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -39,23 +43,15 @@
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/PrettyStackTrace.h"
 #include "llvm/Support/SourceMgr.h"
-#include "llvm/Support/Timer.h"
-#include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Signals.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Support/Timer.h"
+#include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/system_error.h"
-#include "llvm/Target/TargetAsmBackend.h"
-#include "llvm/Target/TargetAsmInfo.h"
-#include "llvm/Target/TargetAsmParser.h"
 #include "llvm/Target/TargetData.h"
-#include "llvm/Target/TargetInstrInfo.h"
-#include "llvm/Target/TargetLowering.h"
-#include "llvm/Target/TargetLoweringObjectFile.h"
-#include "llvm/Target/TargetMachine.h"
-#include "llvm/Target/TargetRegistry.h"
-#include "llvm/Target/TargetSelect.h"
-#include "llvm/Target/TargetSubtargetInfo.h"
 using namespace clang;
 using namespace clang::driver;
 using namespace llvm;
@@ -125,7 +121,7 @@ public:
   }
 
   static void CreateFromArgs(AssemblerInvocation &Res, const char **ArgBegin,
-                             const char **ArgEnd, Diagnostic &Diags);
+                             const char **ArgEnd, DiagnosticsEngine &Diags);
 };
 
 }
@@ -133,7 +129,7 @@ public:
 void AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
                                          const char **ArgBegin,
                                          const char **ArgEnd,
-                                         Diagnostic &Diags) {
+                                         DiagnosticsEngine &Diags) {
   using namespace clang::driver::cc1asoptions;
   // Parse the arguments.
   OwningPtr<OptTable> OptTbl(createCC1AsOptTable());
@@ -207,7 +203,7 @@ void AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
 }
 
 static formatted_raw_ostream *GetOutputStream(AssemblerInvocation &Opts,
-                                              Diagnostic &Diags,
+                                              DiagnosticsEngine &Diags,
                                               bool Binary) {
   if (Opts.OutputPath.empty())
     Opts.OutputPath = "-";
@@ -230,7 +226,8 @@ static formatted_raw_ostream *GetOutputStream(AssemblerInvocation &Opts,
   return new formatted_raw_ostream(*Out, formatted_raw_ostream::DELETE_STREAM);
 }
 
-static bool ExecuteAssembler(AssemblerInvocation &Opts, Diagnostic &Diags) {
+static bool ExecuteAssembler(AssemblerInvocation &Opts,
+                             DiagnosticsEngine &Diags) {
   // Get the target specific parser.
   std::string Error;
   const Target *TheTarget(TargetRegistry::lookupTarget(Opts.Triple, Error));
@@ -259,64 +256,60 @@ static bool ExecuteAssembler(AssemblerInvocation &Opts, Diagnostic &Diags) {
   OwningPtr<MCAsmInfo> MAI(TheTarget->createMCAsmInfo(Opts.Triple));
   assert(MAI && "Unable to create target asm info!");
 
+  OwningPtr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(Opts.Triple));
+  assert(MRI && "Unable to create target register info!");
+
   bool IsBinary = Opts.OutputType == AssemblerInvocation::FT_Obj;
   formatted_raw_ostream *Out = GetOutputStream(Opts, Diags, IsBinary);
   if (!Out)
     return false;
 
-  // FIXME: We shouldn't need to do this (and link in codegen).
-  OwningPtr<TargetMachine> TM(TheTarget->createTargetMachine(Opts.Triple,
-                                                             "", ""));
-  if (!TM) {
-    Diags.Report(diag::err_target_unknown_triple) << Opts.Triple;
-    return false;
-  }
-
-  const TargetAsmInfo *tai = new TargetAsmInfo(*TM);
-  MCContext Ctx(*MAI, tai);
+  // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
+  // MCObjectFileInfo needs a MCContext reference in order to initialize itself.
+  OwningPtr<MCObjectFileInfo> MOFI(new MCObjectFileInfo());
+  MCContext Ctx(*MAI, *MRI, MOFI.get());
+  // FIXME: Assembler behavior can change with -static.
+  MOFI->InitMCObjectFileInfo(Opts.Triple,
+                             Reloc::Default, CodeModel::Default, Ctx);
   if (Opts.SaveTemporaryLabels)
     Ctx.setAllowTemporaryLabels(false);
 
   OwningPtr<MCStreamer> Str;
 
-  const TargetLoweringObjectFile &TLOF =
-    TM->getTargetLowering()->getObjFileLowering();
-  const_cast<TargetLoweringObjectFile&>(TLOF).Initialize(Ctx, *TM);
-
-  const MCSubtargetInfo &STI = TM->getSubtarget<MCSubtargetInfo>();
+  OwningPtr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo());
+  OwningPtr<MCSubtargetInfo>
+    STI(TheTarget->createMCSubtargetInfo(Opts.Triple, "", ""));
 
   // FIXME: There is a bit of code duplication with addPassesToEmitFile.
   if (Opts.OutputType == AssemblerInvocation::FT_Asm) {
     MCInstPrinter *IP =
-      TheTarget->createMCInstPrinter(Opts.OutputAsmVariant, *MAI);
+      TheTarget->createMCInstPrinter(Opts.OutputAsmVariant, *MAI, *STI);
     MCCodeEmitter *CE = 0;
-    TargetAsmBackend *TAB = 0;
+    MCAsmBackend *MAB = 0;
     if (Opts.ShowEncoding) {
-      CE = TheTarget->createCodeEmitter(*TM->getInstrInfo(), STI, Ctx);
-      TAB = TheTarget->createAsmBackend(Opts.Triple);
+      CE = TheTarget->createMCCodeEmitter(*MCII, *STI, Ctx);
+      MAB = TheTarget->createMCAsmBackend(Opts.Triple);
     }
     Str.reset(TheTarget->createAsmStreamer(Ctx, *Out, /*asmverbose*/true,
                                            /*useLoc*/ true,
-                                           /*useCFI*/ true, IP, CE, TAB,
+                                           /*useCFI*/ true, IP, CE, MAB,
                                            Opts.ShowInst));
   } else if (Opts.OutputType == AssemblerInvocation::FT_Null) {
     Str.reset(createNullStreamer(Ctx));
   } else {
     assert(Opts.OutputType == AssemblerInvocation::FT_Obj &&
            "Invalid file type!");
-    MCCodeEmitter *CE = TheTarget->createCodeEmitter(*TM->getInstrInfo(),
-                                                     STI, Ctx);
-    TargetAsmBackend *TAB = TheTarget->createAsmBackend(Opts.Triple);
-    Str.reset(TheTarget->createObjectStreamer(Opts.Triple, Ctx, *TAB, *Out,
-                                              CE, Opts.RelaxAll,
-                                              Opts.NoExecStack));
+    MCCodeEmitter *CE = TheTarget->createMCCodeEmitter(*MCII, *STI, Ctx);
+    MCAsmBackend *MAB = TheTarget->createMCAsmBackend(Opts.Triple);
+    Str.reset(TheTarget->createMCObjectStreamer(Opts.Triple, Ctx, *MAB, *Out,
+                                                CE, Opts.RelaxAll,
+                                                Opts.NoExecStack));
     Str.get()->InitSections();
   }
 
-  OwningPtr<MCAsmParser> Parser(createMCAsmParser(*TheTarget, SrcMgr, Ctx,
+  OwningPtr<MCAsmParser> Parser(createMCAsmParser(SrcMgr, Ctx,
                                                   *Str.get(), *MAI));
-  OwningPtr<TargetAsmParser>
-    TAP(TheTarget->createAsmParser(const_cast<MCSubtargetInfo&>(STI), *Parser));
+  OwningPtr<MCTargetAsmParser> TAP(TheTarget->createMCAsmParser(*STI, *Parser));
   if (!TAP) {
     Diags.Report(diag::err_target_unknown_triple) << Opts.Triple;
     return false;
@@ -337,7 +330,7 @@ static bool ExecuteAssembler(AssemblerInvocation &Opts, Diagnostic &Diags) {
 }
 
 static void LLVMErrorHandler(void *UserData, const std::string &Message) {
-  Diagnostic &Diags = *static_cast<Diagnostic*>(UserData);
+  DiagnosticsEngine &Diags = *static_cast<DiagnosticsEngine*>(UserData);
 
   Diags.Report(diag::err_fe_error_backend) << Message;
 
@@ -354,12 +347,7 @@ int cc1as_main(const char **ArgBegin, const char **ArgEnd,
 
   // Initialize targets and assembly printers/parsers.
   InitializeAllTargetInfos();
-  // FIXME: We shouldn't need to initialize the Target(Machine)s.
-  InitializeAllTargets();
-  InitializeAllMCAsmInfos();
-  InitializeAllMCInstrInfos();
-  InitializeAllMCSubtargetInfos();
-  InitializeAllAsmPrinters();
+  InitializeAllTargetMCs();
   InitializeAllAsmParsers();
 
   // Construct our diagnostic client.
@@ -367,7 +355,7 @@ int cc1as_main(const char **ArgBegin, const char **ArgEnd,
     = new TextDiagnosticPrinter(errs(), DiagnosticOptions());
   DiagClient->setPrefix("clang -cc1as");
   llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
-  Diagnostic Diags(DiagID, DiagClient);
+  DiagnosticsEngine Diags(DiagID, DiagClient);
 
   // Set an error handler, so that any LLVM backend diagnostics go through our
   // error handler.
diff --git a/tools/driver/driver.cpp b/tools/driver/driver.cpp
index ca8982619e94..bd1d2a2f5f35 100644
--- a/tools/driver/driver.cpp
+++ b/tools/driver/driver.cpp
@@ -35,9 +35,9 @@
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Program.h"
 #include "llvm/Support/Signals.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
 #include "llvm/Support/system_error.h"
-#include "llvm/Target/TargetRegistry.h"
-#include "llvm/Target/TargetSelect.h"
 #include <cctype>
 using namespace clang;
 using namespace clang::driver;
@@ -53,7 +53,7 @@ llvm::sys::Path GetExecutablePath(const char *Argv0, bool CanonicalPrefixes) {
 }
 
 static const char *SaveStringInSet(std::set<std::string> &SavedStrings,
-                                   llvm::StringRef S) {
+                                   StringRef S) {
   return SavedStrings.insert(S).first->c_str();
 }
 
@@ -84,9 +84,9 @@ static const char *SaveStringInSet(std::set<std::string> &SavedStrings,
 /// \param Args - The vector of command line arguments.
 /// \param Edit - The override command to perform.
 /// \param SavedStrings - Set to use for storing string representations.
-static void ApplyOneQAOverride(llvm::raw_ostream &OS,
-                               llvm::SmallVectorImpl<const char*> &Args,
-                               llvm::StringRef Edit,
+static void ApplyOneQAOverride(raw_ostream &OS,
+                               SmallVectorImpl<const char*> &Args,
+                               StringRef Edit,
                                std::set<std::string> &SavedStrings) {
   // This does not need to be efficient.
 
@@ -101,9 +101,9 @@ static void ApplyOneQAOverride(llvm::raw_ostream &OS,
     OS << "### Adding argument " << Str << " at end\n";
     Args.push_back(Str);
   } else if (Edit[0] == 's' && Edit[1] == '/' && Edit.endswith("/") &&
-             Edit.slice(2, Edit.size()-1).find('/') != llvm::StringRef::npos) {
-    llvm::StringRef MatchPattern = Edit.substr(2).split('/').first;
-    llvm::StringRef ReplPattern = Edit.substr(2).split('/').second;
+             Edit.slice(2, Edit.size()-1).find('/') != StringRef::npos) {
+    StringRef MatchPattern = Edit.substr(2).split('/').first;
+    StringRef ReplPattern = Edit.substr(2).split('/').second;
     ReplPattern = ReplPattern.slice(0, ReplPattern.size()-1);
 
     for (unsigned i = 1, e = Args.size(); i != e; ++i) {
@@ -151,10 +151,10 @@ static void ApplyOneQAOverride(llvm::raw_ostream &OS,
 
 /// ApplyQAOverride - Apply a comma separate list of edits to the
 /// input argument lists. See ApplyOneQAOverride.
-static void ApplyQAOverride(llvm::SmallVectorImpl<const char*> &Args,
+static void ApplyQAOverride(SmallVectorImpl<const char*> &Args,
                             const char *OverrideStr,
                             std::set<std::string> &SavedStrings) {
-  llvm::raw_ostream *OS = &llvm::errs();
+  raw_ostream *OS = &llvm::errs();
 
   if (OverrideStr[0] == '#') {
     ++OverrideStr;
@@ -184,7 +184,7 @@ extern int cc1as_main(const char **ArgBegin, const char **ArgEnd,
                       const char *Argv0, void *MainAddr);
 
 static void ExpandArgsFromBuf(const char *Arg,
-                              llvm::SmallVectorImpl<const char*> &ArgVector,
+                              SmallVectorImpl<const char*> &ArgVector,
                               std::set<std::string> &SavedStrings) {
   const char *FName = Arg + 1;
   llvm::OwningPtr<llvm::MemoryBuffer> MemBuf;
@@ -242,7 +242,7 @@ static void ExpandArgsFromBuf(const char *Arg,
 }
 
 static void ExpandArgv(int argc, const char **argv,
-                       llvm::SmallVectorImpl<const char*> &ArgVector,
+                       SmallVectorImpl<const char*> &ArgVector,
                        std::set<std::string> &SavedStrings) {
   for (int i = 0; i < argc; ++i) {
     const char *Arg = argv[i];
@@ -255,7 +255,7 @@ static void ExpandArgv(int argc, const char **argv,
   }
 }
 
-static void ParseProgName(llvm::SmallVectorImpl<const char *> &ArgVector,
+static void ParseProgName(SmallVectorImpl<const char *> &ArgVector,
                           std::set<std::string> &SavedStrings,
                           Driver &TheDriver)
 {
@@ -290,8 +290,8 @@ static void ParseProgName(llvm::SmallVectorImpl<const char *> &ArgVector,
     { "++", true, false },
   };
   std::string ProgName(llvm::sys::path::stem(ArgVector[0]));
-  llvm::StringRef ProgNameRef(ProgName);
-  llvm::StringRef Prefix;
+  StringRef ProgNameRef(ProgName);
+  StringRef Prefix;
 
   for (int Components = 2; Components; --Components) {
     bool FoundMatch = false;
@@ -309,15 +309,15 @@ static void ParseProgName(llvm::SmallVectorImpl<const char *> &ArgVector,
     }
 
     if (FoundMatch) {
-      llvm::StringRef::size_type LastComponent = ProgNameRef.rfind('-',
+      StringRef::size_type LastComponent = ProgNameRef.rfind('-',
         ProgNameRef.size() - strlen(suffixes[i].Suffix));
-      if (LastComponent != llvm::StringRef::npos)
+      if (LastComponent != StringRef::npos)
         Prefix = ProgNameRef.slice(0, LastComponent);
       break;
     }
 
-    llvm::StringRef::size_type LastComponent = ProgNameRef.rfind('-');
-    if (LastComponent == llvm::StringRef::npos)
+    StringRef::size_type LastComponent = ProgNameRef.rfind('-');
+    if (LastComponent == StringRef::npos)
       break;
     ProgNameRef = ProgNameRef.slice(0, LastComponent);
   }
@@ -327,7 +327,7 @@ static void ParseProgName(llvm::SmallVectorImpl<const char *> &ArgVector,
 
   std::string IgnoredError;
   if (llvm::TargetRegistry::lookupTarget(Prefix, IgnoredError)) {
-    llvm::SmallVectorImpl<const char *>::iterator it = ArgVector.begin();
+    SmallVectorImpl<const char *>::iterator it = ArgVector.begin();
     if (it != ArgVector.end())
       ++it;
     ArgVector.insert(it, SaveStringInSet(SavedStrings, Prefix));
@@ -341,13 +341,13 @@ int main(int argc_, const char **argv_) {
   llvm::PrettyStackTraceProgram X(argc_, argv_);
 
   std::set<std::string> SavedStrings;
-  llvm::SmallVector<const char*, 256> argv;
+  SmallVector<const char*, 256> argv;
 
   ExpandArgv(argc_, argv_, argv, SavedStrings);
 
   // Handle -cc1 integrated tools.
-  if (argv.size() > 1 && llvm::StringRef(argv[1]).startswith("-cc1")) {
-    llvm::StringRef Tool = argv[1] + 4;
+  if (argv.size() > 1 && StringRef(argv[1]).startswith("-cc1")) {
+    StringRef Tool = argv[1] + 4;
 
     if (Tool == "")
       return cc1_main(argv.data()+2, argv.data()+argv.size(), argv[0],
@@ -363,7 +363,7 @@ int main(int argc_, const char **argv_) {
 
   bool CanonicalPrefixes = true;
   for (int i = 1, size = argv.size(); i < size; ++i) {
-    if (llvm::StringRef(argv[i]) == "-no-canonical-prefixes") {
+    if (StringRef(argv[i]) == "-no-canonical-prefixes") {
       CanonicalPrefixes = false;
       break;
     }
@@ -375,22 +375,15 @@ int main(int argc_, const char **argv_) {
     = new TextDiagnosticPrinter(llvm::errs(), DiagnosticOptions());
   DiagClient->setPrefix(llvm::sys::path::stem(Path.str()));
   llvm::IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
-  Diagnostic Diags(DiagID, DiagClient);
+  DiagnosticsEngine Diags(DiagID, DiagClient);
 
 #ifdef CLANG_IS_PRODUCTION
   const bool IsProduction = true;
-#  ifdef CLANGXX_IS_PRODUCTION
-  const bool CXXIsProduction = true;
-#  else
-  const bool CXXIsProduction = false;
-#  endif
 #else
   const bool IsProduction = false;
-  const bool CXXIsProduction = false;
 #endif
   Driver TheDriver(Path.str(), llvm::sys::getHostTriple(),
-                   "a.out", IsProduction, CXXIsProduction,
-                   Diags);
+                   "a.out", IsProduction, Diags);
 
   // Attempt to find the original path used to invoke the driver, to determine
   // the installed path. We do this manually, because we want to support that
@@ -458,9 +451,15 @@ int main(int argc_, const char **argv_) {
 
   llvm::OwningPtr<Compilation> C(TheDriver.BuildCompilation(argv));
   int Res = 0;
+  const Command *FailingCommand = 0;
   if (C.get())
-    Res = TheDriver.ExecuteCompilation(*C);
-  
+    Res = TheDriver.ExecuteCompilation(*C, FailingCommand);
+
+  // If result status is < 0, then the driver command signalled an error.
+  // In this case, generate additional diagnostic information if possible.
+  if (Res < 0)
+    TheDriver.generateCompilationDiagnostics(*C, FailingCommand);
+
   // If any timers were active but haven't been destroyed yet, print their
   // results now.  This happens in -disable-free mode.
   llvm::TimerGroup::printAll(llvm::errs());