Coverage Mapping: store function's hash in the function's coverage record.

[arphaman]

Summary

Recently, the profile data format was updated to allow for multiple functions with the same name. The updated indexing api requires the code coverage tool to know the function's hash as well as the function's name to get the execution counts for a function. This patch updates clang which now also stores function hashes in function's coverage records.

[arphaman]

Closed by commit rL216208 (authored by @arphaman).

lib/CodeGen/CodeGenPGO.cpp

 
   // Create coverage mapping data variable.
   if (!CoverageMapping.empty())
-    CGM.getCoverageMapping()->addFunctionMappingRecord(Name,
-                                                       getFuncName(),
+    CGM.getCoverageMapping()->addFunctionMappingRecord(Name, getFuncName(),
+                                                       FunctionHash,
                                                        CoverageMapping);
 
   // Hide all these symbols so that we correctly get a copy for each

lib/CodeGen/CoverageMappingGen.h

   /// function mapping records.
   void addFunctionMappingRecord(llvm::GlobalVariable *FunctionName,
                                 StringRef FunctionNameValue,
+                                uint64_t FunctionHash,
                                 const std::string &CoverageMapping);
 
   /// \brief Emit the coverage mapping data for a translation unit.

lib/CodeGen/CoverageMappingGen.cpp

 
 void CoverageMappingModuleGen::addFunctionMappingRecord(
     llvm::GlobalVariable *FunctionName, StringRef FunctionNameValue,
-    const std::string &CoverageMapping) {
+    uint64_t FunctionHash, const std::string &CoverageMapping) {
   llvm::LLVMContext &Ctx = CGM.getLLVMContext();
   auto *Int32Ty = llvm::Type::getInt32Ty(Ctx);
+  auto *Int64Ty = llvm::Type::getInt64Ty(Ctx);
   auto *Int8PtrTy = llvm::Type::getInt8PtrTy(Ctx);
   if (!FunctionRecordTy) {
-    llvm::Type *FunctionRecordTypes[] = {Int8PtrTy, Int32Ty, Int32Ty};
+    llvm::Type *FunctionRecordTypes[] = {Int8PtrTy, Int32Ty, Int32Ty, Int64Ty};
     FunctionRecordTy =
         llvm::StructType::get(Ctx, makeArrayRef(FunctionRecordTypes));
   }

   llvm::Constant *FunctionRecordVals[] = {
       llvm::ConstantExpr::getBitCast(FunctionName, Int8PtrTy),
       llvm::ConstantInt::get(Int32Ty, FunctionNameValue.size()),
-      llvm::ConstantInt::get(Int32Ty, CoverageMapping.size())};
+      llvm::ConstantInt::get(Int32Ty, CoverageMapping.size()),
+      llvm::ConstantInt::get(Int64Ty, FunctionHash)};
   FunctionRecords.push_back(llvm::ConstantStruct::get(
       FunctionRecordTy, makeArrayRef(FunctionRecordVals)));
   CoverageMappings += CoverageMapping;

test/CoverageMapping/ir.c

   return 0;
 }
 
-// CHECK: @__llvm_coverage_mapping = internal constant { i32, i32, i32, i32, [2 x { i8*, i32, i32 }], [{{[0-9]+}} x i8] } { i32 2, i32 {{[0-9]+}}, i32 {{[0-9]+}}, i32 0, [2 x { i8*, i32, i32 }] [{ i8*, i32, i32 } { i8* getelementptr inbounds ([3 x i8]* @__llvm_profile_name_foo, i32 0, i32 0), i32 3, i32 9 }, { i8*, i32, i32 } { i8* getelementptr inbounds ([4 x i8]* @__llvm_profile_name_main, i32 0, i32 0), i32 4, i32 9 }]
+// CHECK: @__llvm_coverage_mapping = internal constant { i32, i32, i32, i32, [2 x { i8*, i32, i32, i64 }], [{{[0-9]+}} x i8] } { i32 2, i32 {{[0-9]+}}, i32 {{[0-9]+}}, i32 0, [2 x { i8*, i32, i32, i64 }] [{ i8*, i32, i32, i64 } { i8* getelementptr inbounds ([3 x i8]* @__llvm_profile_name_foo, i32 0, i32 0), i32 3, i32 9, i64 {{[0-9]+}} }, { i8*, i32, i32, i64 } { i8* getelementptr inbounds ([4 x i8]* @__llvm_profile_name_main, i32 0, i32 0), i32 4, i32 9, i64 {{[0-9]+}} }]