Introduce -fsanitize-coverage=N flag

Summary:
This change makes the asan-coverge (formerly -mllvm -asan-coverge)
accessible via a clang flag.
Companion patch to LLVM is http://reviews.llvm.org/D6152

Test Plan: regression tests, chromium

Reviewers: samsonov

Reviewed By: samsonov

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D6153

llvm-svn: 221719

3 files changed, 32 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 57675b1fe19..41f21312bc2 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -179,6 +179,14 @@ static void addBoundsCheckingPass(const PassManagerBuilder &Builder,
   PM.add(createBoundsCheckingPass());
 }
 
+static void addSanitizerCoveragePass(const PassManagerBuilder &Builder,
+                                     PassManagerBase &PM) {
+  const PassManagerBuilderWrapper &BuilderWrapper =
+      static_cast<const PassManagerBuilderWrapper&>(Builder);
+  const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
+  PM.add(createSanitizerCoverageModulePass(CGOpts.SanitizeCoverage));
+}
+
 static void addAddressSanitizerPasses(const PassManagerBuilder &Builder,
                                       PassManagerBase &PM) {
   PM.add(createAddressSanitizerFunctionPass());
@@ -274,6 +282,13 @@ void EmitAssemblyHelper::CreatePasses() {
                            addBoundsCheckingPass);
   }
 
+  if (CodeGenOpts.SanitizeCoverage) {
+    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
+                           addSanitizerCoveragePass);
+    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
+                           addSanitizerCoveragePass);
+  }
+
   if (LangOpts.Sanitize.has(SanitizerKind::Address)) {
     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
                            addAddressSanitizerPasses);
diff --git a/clang/lib/Driver/SanitizerArgs.cpp b/clang/lib/Driver/SanitizerArgs.cpp
index a920ff95671..24057c5cc1c 100644
--- a/clang/lib/Driver/SanitizerArgs.cpp
+++ b/clang/lib/Driver/SanitizerArgs.cpp
@@ -24,6 +24,7 @@ using namespace llvm::opt;
 void SanitizerArgs::clear() {
   Kind = 0;
   BlacklistFile = "";
+  SanitizeCoverage = 0;
   MsanTrackOrigins = 0;
   AsanFieldPadding = 0;
   AsanZeroBaseShadow = false;
@@ -159,6 +160,17 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
     }
   }
 
+  // Parse -fsanitize-coverage=N
+  if (NeedsAsan) {  // Currently asan is required.
+    if (Arg *A = Args.getLastArg(options::OPT_fsanitize_coverage)) {
+      StringRef S = A->getValue();
+      // Legal values are 0..4.
+      if (S.getAsInteger(0, SanitizeCoverage) || SanitizeCoverage < 0 ||
+          SanitizeCoverage > 4)
+        D.Diag(diag::err_drv_invalid_value) << A->getAsString(Args) << S;
+    }
+  }
+
   if (NeedsAsan) {
     AsanSharedRuntime =
         Args.hasArg(options::OPT_shared_libasan) ||
@@ -219,6 +231,9 @@ void SanitizerArgs::addArgs(const llvm::opt::ArgList &Args,
   if (AsanFieldPadding)
     CmdArgs.push_back(Args.MakeArgString("-fsanitize-address-field-padding=" +
                                          llvm::utostr(AsanFieldPadding)));
+  if (SanitizeCoverage)
+    CmdArgs.push_back(Args.MakeArgString("-fsanitize-coverage=" +
+                                         llvm::utostr(SanitizeCoverage)));
   // Workaround for PR16386.
   if (needsMsanRt())
     CmdArgs.push_back(Args.MakeArgString("-fno-assume-sane-operator-new"));
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index add0c9bdb23..6531a403f4c 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -488,6 +488,8 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.CompressDebugSections = Args.hasArg(OPT_compress_debug_sections);
   Opts.DebugCompilationDir = Args.getLastArgValue(OPT_fdebug_compilation_dir);
   Opts.LinkBitcodeFile = Args.getLastArgValue(OPT_mlink_bitcode_file);
+  Opts.SanitizeCoverage =
+      getLastArgIntValue(Args, OPT_fsanitize_coverage, 0, Diags);
   Opts.SanitizeMemoryTrackOrigins =
       getLastArgIntValue(Args, OPT_fsanitize_memory_track_origins_EQ, 0, Diags);
   Opts.SanitizeUndefinedTrapOnError =