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

This reverts r374324 (git commit 62808631acceaa8b78f8ab9b407eb6b943ff5f77)

I changed the test to not rely on finding the sequence "clang, test,
CoverageMapping" in the CWD used to run the test. Instead it makes its
own internal directory hierarchy of foo/bar/baz and looks for that.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@374403 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;