fix datarace

Author: wlei-llvm

clang/lib/Driver/ToolChains/Clang.cpp

@@ -649,6 +649,8 @@ static void addPGOAndCoverageFlags(const ToolChain &TC, Compilation &C,
     CmdArgs.push_back(Args.MakeArgString(
         Twine("--instrument-cold-function-only-path=") + Path));
     CmdArgs.push_back("-mllvm");
+    CmdArgs.push_back("--pgo-instrument-cold-function-only");
+    CmdArgs.push_back("-mllvm");
     CmdArgs.push_back("--pgo-function-entry-coverage");
   }
 

clang/test/Driver/fprofile-generate-cold-function-coverage.c

@@ -1,6 +1,7 @@
 // RUN: %clang -### -c -fprofile-generate-cold-function-coverage %s 2>&1 | FileCheck %s
 // CHECK: "--instrument-cold-function-only-path=default_%m.profraw" 
 // CHECK: "--pgo-function-entry-coverage"
+// CHECK: "--pgo-instrument-cold-function-only"
 // CHECK-NOT:  "-fprofile-instrument"
 // CHECK-NOT:  "-fprofile-instrument-path=
 

llvm/lib/Passes/PassBuilderPipelines.cpp

@@ -298,7 +298,9 @@ static cl::opt<bool> UseLoopVersioningLICM(
 
 static cl::opt<std::string> InstrumentColdFuncOnlyPath(
     "instrument-cold-function-only-path", cl::init(""),
-    cl::desc("File path for cold function only instrumentation"), cl::Hidden);
+    cl::desc("File path for cold function only instrumentation(requires use "
+             "with --pgo-instrument-cold-function-only)"),
+    cl::Hidden);
 
 extern cl::opt<std::string> UseCtxProfile;
 extern cl::opt<bool> PGOInstrumentColdFunctionOnly;
@@ -1188,10 +1190,13 @@ PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level,
   const bool IsCtxProfUse =
       !UseCtxProfile.empty() && Phase == ThinOrFullLTOPhase::ThinLTOPreLink;
 
-  // Enable cold function coverage instrumentation if
-  // InstrumentColdFuncOnlyPath is provided.
-  const bool IsColdFuncOnlyInstrGen = PGOInstrumentColdFunctionOnly =
-      IsPGOPreLink && !InstrumentColdFuncOnlyPath.empty();
+  assert(
+      (InstrumentColdFuncOnlyPath.empty() || PGOInstrumentColdFunctionOnly) &&
+      "--instrument-cold-function-only-path is provided but "
+      "--pgo-instrument-cold-function-only is not enabled");
+  const bool IsColdFuncOnlyInstrGen = PGOInstrumentColdFunctionOnly &&
+                                      IsPGOPreLink &&
+                                      !InstrumentColdFuncOnlyPath.empty();
 
   if (IsPGOInstrGen || IsPGOInstrUse || IsMemprofUse || IsCtxProfGen ||
       IsCtxProfUse || IsColdFuncOnlyInstrGen)