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

llvm-svn: 374266

1 files changed, 6 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CoverageMappingGen.h b/clang/lib/CodeGen/CoverageMappingGen.h
index 3bf51f59047..2bdc00e2566 100644
--- a/clang/lib/CodeGen/CoverageMappingGen.h
+++ b/clang/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;