From 7cd595df96d5929488063d8ff5cc3b5d800386da Mon Sep 17 00:00:00 2001
From: Reid Kleckner <rnk@google.com>
Date: Mon, 28 Oct 2019 14:40:17 -0700
Subject: [PATCH] Revert "Use -fdebug-compilation-dir to form absolute paths in
 coverage mappings"

This reverts commit 9d4806a387892972fd544c0dcaefb0926126220c.

There seem to be bugs in llvm-cov --path-equivalence that are causing
Chromium problems. Revert this until they are understood or fixed.
---
 clang/lib/CodeGen/CoverageMappingGen.cpp | 25 +++++++-----------------
 clang/lib/CodeGen/CoverageMappingGen.h   |  8 ++------
 clang/test/CoverageMapping/debug-dir.cpp | 16 ---------------
 3 files changed, 9 insertions(+), 40 deletions(-)
 delete mode 100644 clang/test/CoverageMapping/debug-dir.cpp

diff --git a/clang/lib/CodeGen/CoverageMappingGen.cpp b/clang/lib/CodeGen/CoverageMappingGen.cpp
index a6f6e38d5f14..0a7a4fe33ac2 100644
--- a/clang/lib/CodeGen/CoverageMappingGen.cpp
+++ b/clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -1278,6 +1278,13 @@ 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,
@@ -1310,24 +1317,6 @@ 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/clang/lib/CodeGen/CoverageMappingGen.h b/clang/lib/CodeGen/CoverageMappingGen.h
index 2bdc00e25668..3bf51f590479 100644
--- a/clang/lib/CodeGen/CoverageMappingGen.h
+++ b/clang/lib/CodeGen/CoverageMappingGen.h
@@ -54,14 +54,10 @@ 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);
+  CoverageMappingModuleGen(CodeGenModule &CGM, CoverageSourceInfo &SourceInfo)
+      : CGM(CGM), SourceInfo(SourceInfo), FunctionRecordTy(nullptr) {}
 
   CoverageSourceInfo &getSourceInfo() const {
     return SourceInfo;
diff --git a/clang/test/CoverageMapping/debug-dir.cpp b/clang/test/CoverageMapping/debug-dir.cpp
deleted file mode 100644
index 657c9f28134a..000000000000
--- a/clang/test/CoverageMapping/debug-dir.cpp
+++ /dev/null
@@ -1,16 +0,0 @@
-// %s expands to an absolute path, so to test relative paths we need to create a
-// clean directory, put the source there, and cd into it.
-// RUN: rm -rf %t
-// RUN: mkdir -p %t/foo/bar/baz
-// RUN: cp %s %t/foo/bar/baz/debug-dir.cpp
-// RUN: cd %t/foo/bar
-
-// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -emit-llvm -main-file-name debug-dir.cpp baz/debug-dir.cpp  -o - | FileCheck -check-prefix=ABSOLUTE %s
-//
-// ABSOLUTE: @__llvm_coverage_mapping = {{.*"\\01.*foo.*bar.*baz.*debug-dir\.cpp}}
-
-// RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -emit-llvm -main-file-name debug-dir.cpp baz/debug-dir.cpp -fdebug-compilation-dir . -o - | FileCheck -check-prefix=RELATIVE %s
-//
-// RELATIVE: @__llvm_coverage_mapping = {{.*"\\01[^/]*baz.*debug-dir\.cpp}}
-
-void f1() {}