1 files changed, 125 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/sanitizer_common/sanitizer_coverage_mapping_libcdep.cc b/contrib/compiler-rt/lib/sanitizer_common/sanitizer_coverage_mapping_libcdep.cc
new file mode 100644
index 000000000000..fe72d06a2fb1
--- /dev/null
+++ b/contrib/compiler-rt/lib/sanitizer_common/sanitizer_coverage_mapping_libcdep.cc
@@ -0,0 +1,125 @@
+//===-- sanitizer_coverage_mapping.cc -------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Mmap-based implementation of sanitizer coverage.
+//
+// This is part of the implementation of code coverage that does not require
+// __sanitizer_cov_dump() call. Data is stored in 2 files per process.
+//
+// $pid.sancov.map describes process memory layout in the following text-based
+// format:
+// <pointer size in bits>  // 1 line, 32 or 64
+// <mapping start> <mapping end> <base address> <dso name> // repeated
+// ...
+// Mapping lines are NOT sorted. This file is updated every time memory layout
+// is changed (i.e. in dlopen() and dlclose() interceptors).
+//
+// $pid.sancov.raw is a binary dump of PC values, sizeof(uptr) each. Again, not
+// sorted. This file is extended by 64Kb at a time and mapped into memory. It
+// contains one or more 0 words at the end, up to the next 64Kb aligned offset.
+//
+// To convert these 2 files to the usual .sancov format, run sancov.py rawunpack
+// $pid.sancov.raw.
+//
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_allocator_internal.h"
+#include "sanitizer_libc.h"
+#include "sanitizer_procmaps.h"
+
+namespace __sanitizer {
+
+static const uptr kMaxNumberOfModules = 1 << 14;
+static const uptr kMaxTextSize = 64 * 1024;
+
+struct CachedMapping {
+ public:
+  bool NeedsUpdate(uptr pc) {
+    int new_pid = internal_getpid();
+    if (last_pid == new_pid && pc && pc >= last_range_start &&
+        pc < last_range_end)
+      return false;
+    last_pid = new_pid;
+    return true;
+  }
+
+  void SetModuleRange(uptr start, uptr end) {
+    last_range_start = start;
+    last_range_end = end;
+  }
+
+ private:
+  uptr last_range_start, last_range_end;
+  int last_pid;
+};
+
+static CachedMapping cached_mapping;
+static StaticSpinMutex mapping_mu;
+
+void CovUpdateMapping(uptr caller_pc) {
+  if (!common_flags()->coverage || !common_flags()->coverage_direct) return;
+
+  SpinMutexLock l(&mapping_mu);
+
+  if (!cached_mapping.NeedsUpdate(caller_pc))
+    return;
+
+  InternalScopedString text(kMaxTextSize);
+  InternalScopedBuffer<LoadedModule> modules(kMaxNumberOfModules);
+  CHECK(modules.data());
+  int n_modules = GetListOfModules(modules.data(), kMaxNumberOfModules,
+                                   /* filter */ 0);
+
+  text.append("%d\n", sizeof(uptr) * 8);
+  for (int i = 0; i < n_modules; ++i) {
+    const char *module_name = StripModuleName(modules[i].full_name());
+    for (unsigned j = 0; j < modules[i].n_ranges(); ++j) {
+      if (modules[i].address_range_executable(j)) {
+        uptr start = modules[i].address_range_start(j);
+        uptr end = modules[i].address_range_end(j);
+        uptr base = modules[i].base_address();
+        text.append("%zx %zx %zx %s\n", start, end, base, module_name);
+        if (caller_pc && caller_pc >= start && caller_pc < end)
+          cached_mapping.SetModuleRange(start, end);
+      }
+    }
+  }
+
+  int err;
+  InternalScopedString tmp_path(64 +
+                                internal_strlen(common_flags()->coverage_dir));
+  uptr res = internal_snprintf((char *)tmp_path.data(), tmp_path.size(),
+                    "%s/%zd.sancov.map.tmp", common_flags()->coverage_dir,
+                    internal_getpid());
+  CHECK_LE(res, tmp_path.size());
+  uptr map_fd = OpenFile(tmp_path.data(), true);
+  if (internal_iserror(map_fd)) {
+    Report(" Coverage: failed to open %s for writing\n", tmp_path.data());
+    Die();
+  }
+
+  res = internal_write(map_fd, text.data(), text.length());
+  if (internal_iserror(res, &err)) {
+    Printf("sancov.map write failed: %d\n", err);
+    Die();
+  }
+  internal_close(map_fd);
+
+  InternalScopedString path(64 + internal_strlen(common_flags()->coverage_dir));
+  res = internal_snprintf((char *)path.data(), path.size(), "%s/%zd.sancov.map",
+                    common_flags()->coverage_dir, internal_getpid());
+  CHECK_LE(res, path.size());
+  res = internal_rename(tmp_path.data(), path.data());
+  if (internal_iserror(res, &err)) {
+    Printf("sancov.map rename failed: %d\n", err);
+    Die();
+  }
+}
+
+}  // namespace __sanitizer