Add coverage mapping generation.
This patch adds the '-fcoverage-mapping' option which
allows clang to generate the coverage mapping information
that can be used to provide code coverage analysis using
the execution counts obtained from the instrumentation
based profiling (-fprofile-instr-generate).
llvm-svn: 214752
diff --git a/clang/lib/CodeGen/CodeGenPGO.cpp b/clang/lib/CodeGen/CodeGenPGO.cpp
index 4def789..e6dbad8 100644
--- a/clang/lib/CodeGen/CodeGenPGO.cpp
+++ b/clang/lib/CodeGen/CodeGenPGO.cpp
@@ -13,6 +13,7 @@
#include "CodeGenPGO.h"
#include "CodeGenFunction.h"
+#include "CoverageMappingGen.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/StmtVisitor.h"
#include "llvm/IR/MDBuilder.h"
@@ -24,8 +25,9 @@
using namespace clang;
using namespace CodeGen;
-void CodeGenPGO::setFuncName(llvm::Function *Fn) {
- RawFuncName = Fn->getName();
+void CodeGenPGO::setFuncName(StringRef Name,
+ llvm::GlobalValue::LinkageTypes Linkage) {
+ RawFuncName = Name;
// Function names may be prefixed with a binary '1' to indicate
// that the backend should not modify the symbols due to any platform
@@ -33,7 +35,7 @@
if (RawFuncName[0] == '\1')
RawFuncName = RawFuncName.substr(1);
- if (!Fn->hasLocalLinkage()) {
+ if (!llvm::GlobalValue::isLocalLinkage(Linkage)) {
PrefixedFuncName.reset(new std::string(RawFuncName));
return;
}
@@ -49,6 +51,27 @@
PrefixedFuncName->append(RawFuncName);
}
+void CodeGenPGO::setFuncName(llvm::Function *Fn) {
+ setFuncName(Fn->getName(), Fn->getLinkage());
+}
+
+void CodeGenPGO::setVarLinkage(llvm::GlobalValue::LinkageTypes Linkage) {
+ // Set the linkage for variables based on the function linkage. Usually, we
+ // want to match it, but available_externally and extern_weak both have the
+ // wrong semantics.
+ VarLinkage = Linkage;
+ switch (VarLinkage) {
+ case llvm::GlobalValue::ExternalWeakLinkage:
+ VarLinkage = llvm::GlobalValue::LinkOnceAnyLinkage;
+ break;
+ case llvm::GlobalValue::AvailableExternallyLinkage:
+ VarLinkage = llvm::GlobalValue::LinkOnceODRLinkage;
+ break;
+ default:
+ break;
+ }
+}
+
static llvm::Function *getRegisterFunc(CodeGenModule &CGM) {
return CGM.getModule().getFunction("__llvm_profile_register_functions");
}
@@ -120,37 +143,48 @@
auto *Int64Ty = llvm::Type::getInt64Ty(Ctx);
auto *Int8PtrTy = llvm::Type::getInt8PtrTy(Ctx);
auto *Int64PtrTy = llvm::Type::getInt64PtrTy(Ctx);
- llvm::Type *DataTypes[] = {
- Int32Ty, Int32Ty, Int64Ty, Int8PtrTy, Int64PtrTy
- };
- auto *DataTy = llvm::StructType::get(Ctx, makeArrayRef(DataTypes));
- llvm::Constant *DataVals[] = {
- llvm::ConstantInt::get(Int32Ty, getFuncName().size()),
- llvm::ConstantInt::get(Int32Ty, NumRegionCounters),
- llvm::ConstantInt::get(Int64Ty, FunctionHash),
- llvm::ConstantExpr::getBitCast(Name, Int8PtrTy),
- llvm::ConstantExpr::getBitCast(RegionCounters, Int64PtrTy)
- };
- auto *Data =
- new llvm::GlobalVariable(CGM.getModule(), DataTy, true, VarLinkage,
- llvm::ConstantStruct::get(DataTy, DataVals),
- getFuncVarName("data"));
+ llvm::GlobalVariable *Data = nullptr;
+ if (RegionCounters) {
+ llvm::Type *DataTypes[] = {
+ Int32Ty, Int32Ty, Int64Ty, Int8PtrTy, Int64PtrTy
+ };
+ auto *DataTy = llvm::StructType::get(Ctx, makeArrayRef(DataTypes));
+ llvm::Constant *DataVals[] = {
+ llvm::ConstantInt::get(Int32Ty, getFuncName().size()),
+ llvm::ConstantInt::get(Int32Ty, NumRegionCounters),
+ llvm::ConstantInt::get(Int64Ty, FunctionHash),
+ llvm::ConstantExpr::getBitCast(Name, Int8PtrTy),
+ llvm::ConstantExpr::getBitCast(RegionCounters, Int64PtrTy)
+ };
+ Data =
+ new llvm::GlobalVariable(CGM.getModule(), DataTy, true, VarLinkage,
+ llvm::ConstantStruct::get(DataTy, DataVals),
+ getFuncVarName("data"));
- // All the data should be packed into an array in its own section.
- Data->setSection(getDataSection(CGM));
- Data->setAlignment(8);
+ // All the data should be packed into an array in its own section.
+ Data->setSection(getDataSection(CGM));
+ Data->setAlignment(8);
+ }
+
+ // Create coverage mapping data variable.
+ if (!CoverageMapping.empty())
+ CGM.getCoverageMapping()->addFunctionMappingRecord(Name,
+ getFuncName().size(),
+ CoverageMapping);
// Hide all these symbols so that we correctly get a copy for each
// executable. The profile format expects names and counters to be
// contiguous, so references into shared objects would be invalid.
if (!llvm::GlobalValue::isLocalLinkage(VarLinkage)) {
Name->setVisibility(llvm::GlobalValue::HiddenVisibility);
- Data->setVisibility(llvm::GlobalValue::HiddenVisibility);
- RegionCounters->setVisibility(llvm::GlobalValue::HiddenVisibility);
+ if (Data) {
+ Data->setVisibility(llvm::GlobalValue::HiddenVisibility);
+ RegionCounters->setVisibility(llvm::GlobalValue::HiddenVisibility);
+ }
}
// Make sure the data doesn't get deleted.
- CGM.addUsedGlobal(Data);
+ if (Data) CGM.addUsedGlobal(Data);
return Data;
}
@@ -807,6 +841,20 @@
CGM.addUsedGlobal(User);
}
+void CodeGenPGO::checkGlobalDecl(GlobalDecl GD) {
+ // Make sure we only emit coverage mapping for one constructor/destructor.
+ // Clang emits several functions for the constructor and the destructor of
+ // a class. Every function is instrumented, but we only want to provide
+ // coverage for one of them. Because of that we only emit the coverage mapping
+ // for the base constructor/destructor.
+ if ((isa<CXXConstructorDecl>(GD.getDecl()) &&
+ GD.getCtorType() != Ctor_Base) ||
+ (isa<CXXDestructorDecl>(GD.getDecl()) &&
+ GD.getDtorType() != Dtor_Base)) {
+ SkipCoverageMapping = true;
+ }
+}
+
void CodeGenPGO::assignRegionCounters(const Decl *D, llvm::Function *Fn) {
bool InstrumentRegions = CGM.getCodeGenOpts().ProfileInstrGenerate;
llvm::IndexedInstrProfReader *PGOReader = CGM.getPGOReader();
@@ -814,27 +862,16 @@
return;
if (D->isImplicit())
return;
+ CGM.ClearUnusedCoverageMapping(D);
setFuncName(Fn);
-
- // Set the linkage for variables based on the function linkage. Usually, we
- // want to match it, but available_externally and extern_weak both have the
- // wrong semantics.
- VarLinkage = Fn->getLinkage();
- switch (VarLinkage) {
- case llvm::GlobalValue::ExternalWeakLinkage:
- VarLinkage = llvm::GlobalValue::LinkOnceAnyLinkage;
- break;
- case llvm::GlobalValue::AvailableExternallyLinkage:
- VarLinkage = llvm::GlobalValue::LinkOnceODRLinkage;
- break;
- default:
- break;
- }
+ setVarLinkage(Fn->getLinkage());
mapRegionCounters(D);
if (InstrumentRegions) {
emitRuntimeHook(CGM);
emitCounterVariables();
+ if (CGM.getCodeGenOpts().CoverageMapping)
+ emitCounterRegionMapping(D);
}
if (PGOReader) {
SourceManager &SM = CGM.getContext().getSourceManager();
@@ -860,6 +897,45 @@
FunctionHash = Walker.Hash.finalize();
}
+void CodeGenPGO::emitCounterRegionMapping(const Decl *D) {
+ if (SkipCoverageMapping)
+ return;
+ // Don't map the functions inside the system headers
+ auto Loc = D->getBody()->getLocStart();
+ if (CGM.getContext().getSourceManager().isInSystemHeader(Loc))
+ return;
+
+ llvm::raw_string_ostream OS(CoverageMapping);
+ CoverageMappingGen MappingGen(*CGM.getCoverageMapping(),
+ CGM.getContext().getSourceManager(),
+ CGM.getLangOpts(), RegionCounterMap.get(),
+ NumRegionCounters);
+ MappingGen.emitCounterMapping(D, OS);
+ OS.flush();
+}
+
+void
+CodeGenPGO::emitEmptyCounterMapping(const Decl *D, StringRef FuncName,
+ llvm::GlobalValue::LinkageTypes Linkage) {
+ if (SkipCoverageMapping)
+ return;
+ setFuncName(FuncName, Linkage);
+ setVarLinkage(Linkage);
+
+ // Don't map the functions inside the system headers
+ auto Loc = D->getBody()->getLocStart();
+ if (CGM.getContext().getSourceManager().isInSystemHeader(Loc))
+ return;
+
+ llvm::raw_string_ostream OS(CoverageMapping);
+ CoverageMappingGen MappingGen(*CGM.getCoverageMapping(),
+ CGM.getContext().getSourceManager(),
+ CGM.getLangOpts());
+ MappingGen.emitEmptyMapping(D, OS);
+ OS.flush();
+ buildDataVar();
+}
+
void CodeGenPGO::computeRegionCounts(const Decl *D) {
StmtCountMap.reset(new llvm::DenseMap<const Stmt *, uint64_t>);
ComputeRegionCounts Walker(*StmtCountMap, *this);