Use -fdebug-compilation-dir to form absolute paths in coverage mappings

This allows users to explicitly request relative paths with
`-fdebug-compilation-dir .`.

Fixes PR43614

Reviewers: vsk, arphaman

Differential Revision: https://reviews.llvm.org/D68733

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@374266 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 24 insertions, 9 deletions

diff --git a/lib/CodeGen/CoverageMappingGen.cpp b/lib/CodeGen/CoverageMappingGen.cpp
index 0a7a4fe33a..a6f6e38d5f 100644
--- a/lib/CodeGen/CoverageMappingGen.cpp
+++ b/lib/CodeGen/CoverageMappingGen.cpp
@@ -1278,13 +1278,6 @@ std::string getCoverageSection(const CodeGenModule &CGM) {
       CGM.getContext().getTargetInfo().getTriple().getObjectFormat());
 }
 
-std::string normalizeFilename(StringRef Filename) {
-  llvm::SmallString<256> Path(Filename);
-  llvm::sys::fs::make_absolute(Path);
-  llvm::sys::path::remove_dots(Path, /*remove_dot_dot=*/true);
-  return Path.str().str();
-}
-
 } // end anonymous namespace
 
 static void dump(llvm::raw_ostream &OS, StringRef FunctionName,
@@ -1317,6 +1310,24 @@ static void dump(llvm::raw_ostream &OS, StringRef FunctionName,
   }
 }
 
+CoverageMappingModuleGen::CoverageMappingModuleGen(
+    CodeGenModule &CGM, CoverageSourceInfo &SourceInfo)
+    : CGM(CGM), SourceInfo(SourceInfo), FunctionRecordTy(nullptr) {
+  // Honor -fdebug-compilation-dir in paths in coverage data. Otherwise, use the
+  // regular working directory when normalizing paths.
+  if (!CGM.getCodeGenOpts().DebugCompilationDir.empty())
+    CWD = CGM.getCodeGenOpts().DebugCompilationDir;
+  else
+    llvm::sys::fs::current_path(CWD);
+}
+
+std::string CoverageMappingModuleGen::normalizeFilename(StringRef Filename) {
+  llvm::SmallString<256> Path(Filename);
+  llvm::sys::fs::make_absolute(CWD, Path);
+  llvm::sys::path::remove_dots(Path, /*remove_dot_dot=*/true);
+  return Path.str().str();
+}
+
 void CoverageMappingModuleGen::addFunctionMappingRecord(
     llvm::GlobalVariable *NamePtr, StringRef NameValue, uint64_t FuncHash,
     const std::string &CoverageMapping, bool IsUsed) {
diff --git a/lib/CodeGen/CoverageMappingGen.h b/lib/CodeGen/CoverageMappingGen.h
index 3bf51f5904..2bdc00e256 100644
--- a/lib/CodeGen/CoverageMappingGen.h
+++ b/lib/CodeGen/CoverageMappingGen.h
@@ -54,10 +54,14 @@ class CoverageMappingModuleGen {
   std::vector<llvm::Constant *> FunctionNames;
   llvm::StructType *FunctionRecordTy;
   std::vector<std::string> CoverageMappings;
+  SmallString<256> CWD;
+
+  /// Make the filename absolute, remove dots, and normalize slashes to local
+  /// path style.
+  std::string normalizeFilename(StringRef Filename);
 
 public:
-  CoverageMappingModuleGen(CodeGenModule &CGM, CoverageSourceInfo &SourceInfo)
-      : CGM(CGM), SourceInfo(SourceInfo), FunctionRecordTy(nullptr) {}
+  CoverageMappingModuleGen(CodeGenModule &CGM, CoverageSourceInfo &SourceInfo);
 
   CoverageSourceInfo &getSourceInfo() const {
     return SourceInfo;