Revert "[Coverage] Revise format to reduce binary size"

This reverts commit 9931712. This is
still busted on Windows:

http://lab.llvm.org:8011/builders/lld-x86_64-win7/builds/40873

The llvm-cov tests report 'error: Could not load coverage information'.

clang/lib/CodeGen/CoverageMappingGen.cpp

@@ -13,8 +13,6 @@
 #include "CoverageMappingGen.h"
 #include "CodeGenFunction.h"
 #include "clang/AST/StmtVisitor.h"
-#include "clang/Basic/Diagnostic.h"
-#include "clang/Frontend/FrontendDiagnostic.h"
 #include "clang/Lex/Lexer.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/StringExtras.h"
@@ -26,10 +24,6 @@
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
 
-// This selects the coverage mapping format defined when `InstrProfData.inc`
-// is textually included.
-#define COVMAP_V3
-
 using namespace clang;
 using namespace CodeGen;
 using namespace llvm::coverage;
@@ -1278,6 +1272,12 @@ struct CounterCoverageMappingBuilder
   }
 };
 
+std::string getCoverageSection(const CodeGenModule &CGM) {
+  return llvm::getInstrProfSectionName(
+      llvm::IPSK_covmap,
+      CGM.getContext().getTargetInfo().getTriple().getObjectFormat());
+}
+
 std::string normalizeFilename(StringRef Filename) {
   llvm::SmallString<256> Path(Filename);
   llvm::sys::fs::make_absolute(Path);
@@ -1317,71 +1317,30 @@ static void dump(llvm::raw_ostream &OS, StringRef FunctionName,
   }
 }
 
-static std::string getInstrProfSection(const CodeGenModule &CGM,
-                                       llvm::InstrProfSectKind SK) {
-  return llvm::getInstrProfSectionName(
-      SK, CGM.getContext().getTargetInfo().getTriple().getObjectFormat());
-}
-
-void CoverageMappingModuleGen::emitFunctionMappingRecord(
-    const FunctionInfo &Info, uint64_t FilenamesRef) {
+void CoverageMappingModuleGen::addFunctionMappingRecord(
+    llvm::GlobalVariable *NamePtr, StringRef NameValue, uint64_t FuncHash,
+    const std::string &CoverageMapping, bool IsUsed) {
   llvm::LLVMContext &Ctx = CGM.getLLVMContext();
-
-  // Assign a name to the function record. This is used to merge duplicates.
-  std::string FuncRecordName = "__covrec_" + llvm::utohexstr(Info.NameHash);
-
-  // A dummy description for a function included-but-not-used in a TU can be
-  // replaced by full description provided by a different TU. The two kinds of
-  // descriptions play distinct roles: therefore, assign them different names
-  // to prevent `linkonce_odr` merging.
-  if (Info.IsUsed)
-    FuncRecordName += "u";
-
-  // Create the function record type.
-  const uint64_t NameHash = Info.NameHash;
-  const uint64_t FuncHash = Info.FuncHash;
-  const std::string &CoverageMapping = Info.CoverageMapping;
+  if (!FunctionRecordTy) {
 #define COVMAP_FUNC_RECORD(Type, LLVMType, Name, Init) LLVMType,
-  llvm::Type *FunctionRecordTypes[] = {
-#include "llvm/ProfileData/InstrProfData.inc"
-  };
-  auto *FunctionRecordTy =
-      llvm::StructType::get(Ctx, makeArrayRef(FunctionRecordTypes),
-                            /*isPacked=*/true);
+    llvm::Type *FunctionRecordTypes[] = {
+      #include "llvm/ProfileData/InstrProfData.inc"
+    };
+    FunctionRecordTy =
+        llvm::StructType::get(Ctx, makeArrayRef(FunctionRecordTypes),
+                              /*isPacked=*/true);
+  }
 
-  // Create the function record constant.
-#define COVMAP_FUNC_RECORD(Type, LLVMType, Name, Init) Init,
+  #define COVMAP_FUNC_RECORD(Type, LLVMType, Name, Init) Init,
   llvm::Constant *FunctionRecordVals[] = {
       #include "llvm/ProfileData/InstrProfData.inc"
   };
-  auto *FuncRecordConstant = llvm::ConstantStruct::get(
-      FunctionRecordTy, makeArrayRef(FunctionRecordVals));
-
-  // Create the function record global.
-  auto *FuncRecord = new llvm::GlobalVariable(
-      CGM.getModule(), FunctionRecordTy, /*isConstant=*/true,
-      llvm::GlobalValue::LinkOnceODRLinkage, FuncRecordConstant,
-      FuncRecordName);
-  FuncRecord->setVisibility(llvm::GlobalValue::HiddenVisibility);
-  FuncRecord->setSection(getInstrProfSection(CGM, llvm::IPSK_covfun));
-  FuncRecord->setAlignment(llvm::Align(8));
-  if (CGM.supportsCOMDAT())
-    FuncRecord->setComdat(CGM.getModule().getOrInsertComdat(FuncRecordName));
-
-  // Make sure the data doesn't get deleted.
-  CGM.addUsedGlobal(FuncRecord);
-}
-
-void CoverageMappingModuleGen::addFunctionMappingRecord(
-    llvm::GlobalVariable *NamePtr, StringRef NameValue, uint64_t FuncHash,
-    const std::string &CoverageMapping, bool IsUsed) {
-  llvm::LLVMContext &Ctx = CGM.getLLVMContext();
-  const uint64_t NameHash = llvm::IndexedInstrProf::ComputeHash(NameValue);
-  FunctionRecords.push_back({NameHash, FuncHash, CoverageMapping, IsUsed});
-
+  FunctionRecords.push_back(llvm::ConstantStruct::get(
+      FunctionRecordTy, makeArrayRef(FunctionRecordVals)));
   if (!IsUsed)
     FunctionNames.push_back(
         llvm::ConstantExpr::getBitCast(NamePtr, llvm::Type::getInt8PtrTy(Ctx)));
+  CoverageMappings.push_back(CoverageMapping);
 
   if (CGM.getCodeGenOpts().DumpCoverageMapping) {
     // Dump the coverage mapping data for this function by decoding the
@@ -1426,22 +1385,37 @@ void CoverageMappingModuleGen::emit() {
     FilenameRefs[I] = FilenameStrs[I];
   }
 
-  std::string Filenames;
-  {
-    llvm::raw_string_ostream OS(Filenames);
-    CoverageFilenamesSectionWriter(FilenameRefs).write(OS);
+  std::string FilenamesAndCoverageMappings;
+  llvm::raw_string_ostream OS(FilenamesAndCoverageMappings);
+  CoverageFilenamesSectionWriter(FilenameRefs).write(OS);
+
+  // Stream the content of CoverageMappings to OS while keeping
+  // memory consumption under control.
+  size_t CoverageMappingSize = 0;
+  for (auto &S : CoverageMappings) {
+    CoverageMappingSize += S.size();
+    OS << S;
+    S.clear();
+    S.shrink_to_fit();
   }
-  auto *FilenamesVal =
-      llvm::ConstantDataArray::getString(Ctx, Filenames, false);
-  const int64_t FilenamesRef = llvm::IndexedInstrProf::ComputeHash(Filenames);
+  CoverageMappings.clear();
+  CoverageMappings.shrink_to_fit();
 
-  // Emit the function records.
-  for (const FunctionInfo &Info : FunctionRecords)
-    emitFunctionMappingRecord(Info, FilenamesRef);
+  size_t FilenamesSize = OS.str().size() - CoverageMappingSize;
+  // Append extra zeroes if necessary to ensure that the size of the filenames
+  // and coverage mappings is a multiple of 8.
+  if (size_t Rem = OS.str().size() % 8) {
+    CoverageMappingSize += 8 - Rem;
+    OS.write_zeros(8 - Rem);
+  }
+  auto *FilenamesAndMappingsVal =
+      llvm::ConstantDataArray::getString(Ctx, OS.str(), false);
+
+  // Create the deferred function records array
+  auto RecordsTy =
+      llvm::ArrayType::get(FunctionRecordTy, FunctionRecords.size());
+  auto RecordsVal = llvm::ConstantArray::get(RecordsTy, FunctionRecords);
 
-  const unsigned NRecords = 0;
-  const size_t FilenamesSize = Filenames.size();
-  const unsigned CoverageMappingSize = 0;
   llvm::Type *CovDataHeaderTypes[] = {
 #define COVMAP_HEADER(Type, LLVMType, Name, Init) LLVMType,
 #include "llvm/ProfileData/InstrProfData.inc"
@@ -1456,16 +1430,18 @@ void CoverageMappingModuleGen::emit() {
       CovDataHeaderTy, makeArrayRef(CovDataHeaderVals));
 
   // Create the coverage data record
-  llvm::Type *CovDataTypes[] = {CovDataHeaderTy, FilenamesVal->getType()};
+  llvm::Type *CovDataTypes[] = {CovDataHeaderTy, RecordsTy,
+                                FilenamesAndMappingsVal->getType()};
   auto CovDataTy = llvm::StructType::get(Ctx, makeArrayRef(CovDataTypes));
-  llvm::Constant *TUDataVals[] = {CovDataHeaderVal, FilenamesVal};
+  llvm::Constant *TUDataVals[] = {CovDataHeaderVal, RecordsVal,
+                                  FilenamesAndMappingsVal};
   auto CovDataVal =
       llvm::ConstantStruct::get(CovDataTy, makeArrayRef(TUDataVals));
   auto CovData = new llvm::GlobalVariable(
-      CGM.getModule(), CovDataTy, true, llvm::GlobalValue::PrivateLinkage,
+      CGM.getModule(), CovDataTy, true, llvm::GlobalValue::InternalLinkage,
       CovDataVal, llvm::getCoverageMappingVarName());
 
-  CovData->setSection(getInstrProfSection(CGM, llvm::IPSK_covmap));
+  CovData->setSection(getCoverageSection(CGM));
   CovData->setAlignment(llvm::Align(8));
 
   // Make sure the data doesn't get deleted.

clang/lib/CodeGen/CoverageMappingGen.h

@@ -47,27 +47,17 @@ class CodeGenModule;
 /// Organizes the cross-function state that is used while generating
 /// code coverage mapping data.
 class CoverageMappingModuleGen {
-  /// Information needed to emit a coverage record for a function.
-  struct FunctionInfo {
-    uint64_t NameHash;
-    uint64_t FuncHash;
-    std::string CoverageMapping;
-    bool IsUsed;
-  };
-
   CodeGenModule &CGM;
   CoverageSourceInfo &SourceInfo;
   llvm::SmallDenseMap<const FileEntry *, unsigned, 8> FileEntries;
+  std::vector<llvm::Constant *> FunctionRecords;
   std::vector<llvm::Constant *> FunctionNames;
-  std::vector<FunctionInfo> FunctionRecords;
-
-  /// Emit a function record.
-  void emitFunctionMappingRecord(const FunctionInfo &Info,
-                                 uint64_t FilenamesRef);
+  llvm::StructType *FunctionRecordTy;
+  std::vector<std::string> CoverageMappings;
 
 public:
   CoverageMappingModuleGen(CodeGenModule &CGM, CoverageSourceInfo &SourceInfo)
-      : CGM(CGM), SourceInfo(SourceInfo) {}
+      : CGM(CGM), SourceInfo(SourceInfo), FunctionRecordTy(nullptr) {}
 
   CoverageSourceInfo &getSourceInfo() const {
     return SourceInfo;

clang/test/CoverageMapping/abspath.cpp

@@ -1,12 +1,12 @@
-// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -mllvm -enable-name-compression=false -emit-llvm -main-file-name abspath.cpp %S/Inputs/../abspath.cpp -o - | FileCheck -check-prefix=RMDOTS %s
+// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -emit-llvm -main-file-name abspath.cpp %S/Inputs/../abspath.cpp -o - | FileCheck -check-prefix=RMDOTS %s
 
 // RMDOTS: @__llvm_coverage_mapping = {{.*}}"\01
 // RMDOTS-NOT: Inputs
 // RMDOTS: "
 
 // RUN: mkdir -p %t/test && cd %t/test
 // RUN: echo "void f1() {}" > f1.c
-// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -mllvm -enable-name-compression=false -emit-llvm -main-file-name abspath.cpp ../test/f1.c -o - | FileCheck -check-prefix=RELPATH %s
+// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -emit-llvm -main-file-name abspath.cpp ../test/f1.c -o - | FileCheck -check-prefix=RELPATH %s
 
 // RELPATH: @__llvm_coverage_mapping = {{.*}}"\01
 // RELPATH: {{[/\\].*(/|\\\\)test(/|\\\\)f1}}.c

clang/test/CoverageMapping/ir.c

@@ -1,31 +1,12 @@
 // Check the data structures emitted by coverage mapping
-// RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name ir.c %s -o - -emit-llvm -fprofile-instrument=clang -fcoverage-mapping -mllvm -enable-name-compression=false | FileCheck %s -check-prefixes=COMMON,DARWIN
-// RUN: %clang_cc1 -triple x86_64--windows-msvc -main-file-name ir.c %s -o - -emit-llvm -fprofile-instrument=clang -fcoverage-mapping -mllvm -enable-name-compression=false | FileCheck %s -check-prefixes=COMMON,WINDOWS
+// RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name ir.c %s -o - -emit-llvm -fprofile-instrument=clang -fcoverage-mapping | FileCheck %s
 
-static inline void unused() {}
 
-void foo(void) {}
+void foo(void) { }
 
 int main(void) {
   foo();
   return 0;
 }
 
-// Check the function records. Two of the record names should come in the 'used'
-// flavor, and one should not.
-
-// DARWIN: [[FuncRecord1:@__covrec_[0-9A-F]+u]] = linkonce_odr hidden constant <{ i64, i32, i64, i64, [{{.*}} x i8] }> <{ {{.*}} }>, section "__LLVM_COV,__llvm_covfun", align 8
-// DARWIN: [[FuncRecord2:@__covrec_[0-9A-F]+u]] = linkonce_odr hidden constant <{ i64, i32, i64, i64, [{{.*}} x i8] }> <{ {{.*}} }>, section "__LLVM_COV,__llvm_covfun", align 8
-// DARWIN: [[FuncRecord3:@__covrec_[0-9A-F]+]] = linkonce_odr hidden constant <{ i64, i32, i64, i64, [{{.*}} x i8] }> <{ {{.*}} }>, section "__LLVM_COV,__llvm_covfun", align 8
-// DARWIN: @__llvm_coverage_mapping = private constant { { i32, i32, i32, i32 }, [{{.*}} x i8] } { {{.*}} }, section "__LLVM_COV,__llvm_covmap", align 8
-
-// WINDOWS: [[FuncRecord1:@__covrec_[0-9A-F]+u]] = linkonce_odr hidden constant <{ i64, i32, i64, i64, [{{.*}} x i8] }> <{ {{.*}} }>, section ".lcovfun$M", comdat, align 8
-// WINDOWS: [[FuncRecord2:@__covrec_[0-9A-F]+u]] = linkonce_odr hidden constant <{ i64, i32, i64, i64, [{{.*}} x i8] }> <{ {{.*}} }>, section ".lcovfun$M", comdat, align 8
-// WINDOWS: [[FuncRecord3:@__covrec_[0-9A-F]+]] = linkonce_odr hidden constant <{ i64, i32, i64, i64, [{{.*}} x i8] }> <{ {{.*}} }>, section ".lcovfun$M", comdat, align 8
-// WINDOWS: @__llvm_coverage_mapping = private constant { { i32, i32, i32, i32 }, [{{.*}} x i8] } { {{.*}} }, section ".lcovmap$M", align 8
-
-// COMMON: @llvm.used = appending global [{{.*}} x i8*]
-// COMMON-SAME: [[FuncRecord1]]
-// COMMON-SAME: [[FuncRecord2]]
-// COMMON-SAME: [[FuncRecord3]]
-// COMMON-SAME: @__llvm_coverage_mapping
+// CHECK: @__llvm_coverage_mapping = internal constant { { i32, i32, i32, i32 }, [2 x <{ i64, i32, i64 }>], [{{[0-9]+}} x i8] } { { i32, i32, i32, i32 } { i32 2, i32 {{[0-9]+}}, i32 {{[0-9]+}}, i32 {{[0-9]+}} }, [2 x <{ i64, i32, i64 }>] [<{{.*}}> <{{.*}}>, <{{.*}}> <{{.*}}>]

clang/test/Profile/def-assignop.cpp

@@ -18,12 +18,9 @@ struct A {
   // PGOGEN: {{.*}}add{{.*}}%pgocount, 1
   // PGOGEN: store{{.*}}@__profc__ZN1AaSEOS_
 
-  // Check that coverage mapping includes 3 function records including the
+  // Check that coverage mapping includes 6 function records including the
   // defaulted copy and move operators: A::operator=
-  // COVMAP: section "__llvm_covfun", comdat
-  // COVMAP: section "__llvm_covfun", comdat
-  // COVMAP: section "__llvm_covfun", comdat
-  // COVMAP: @__llvm_coverage_mapping = {{.*}} { { i32, i32, i32, i32 }
+  // COVMAP: @__llvm_coverage_mapping = {{.*}} { { i32, i32, i32, i32 }, [3 x <{{.*}}>],
   B b;
 };
 

clang/test/Profile/def-ctors.cpp

@@ -20,15 +20,11 @@ struct Derived : public Base {
   // PGOGEN-DAG: {{.*}}add{{.*}}%pgocount, 1
   // PGOGEN-DAG: store{{.*}}@__profc__ZN7DerivedC2Ev
 
-  // Check that coverage mapping has 5 function records including
+  // Check that coverage mapping has 6 function records including
   // the defaulted Derived::Derived(const Derived), and Derived::Derived()
   // methds.
-  // COVMAP: section "__llvm_covfun", comdat
-  // COVMAP: section "__llvm_covfun", comdat
-  // COVMAP: section "__llvm_covfun", comdat
-  // COVMAP: section "__llvm_covfun", comdat
-  // COVMAP: section "__llvm_covfun", comdat
-  // COVMAP: @__llvm_coverage_mapping = {{.*}} { { i32, i32, i32, i32 }
+  // COVMAP: @__llvm_coverage_mapping = {{.*}} { { i32, i32, i32, i32 }, [5 x
+  // <{{.*}}>],
 };
 
 Derived dd;

clang/test/Profile/def-dtors.cpp

@@ -16,14 +16,10 @@ struct Derived : public Base {
   // PGOGEN: {{.*}}add{{.*}}%pgocount, 1
   // PGOGEN: store{{.*}}@__profc__ZN7DerivedD2Ev
 
-  // Check that coverage mapping has 5 function records including
+  // Check that coverage mapping has 6 function records including
   // the default destructor in the derived class.
-  // COVMAP: section "__llvm_covfun", comdat
-  // COVMAP: section "__llvm_covfun", comdat
-  // COVMAP: section "__llvm_covfun", comdat
-  // COVMAP: section "__llvm_covfun", comdat
-  // COVMAP: section "__llvm_covfun", comdat
-  // COVMAP: @__llvm_coverage_mapping = {{.*}} { { i32, i32, i32, i32 }
+  // COVMAP: @__llvm_coverage_mapping = {{.*}} { { i32, i32, i32, i32 }, [5 x
+  // <{{.*}}>],
 };
 
 int main() {