[codeview] Merge file checksum entries for DIFiles with the same absolute path

Change the map key from DIFile* to the absolute path string. Computing
the absolute path isn't expensive because we already have a map that
caches the full path keyed on DIFile*.

llvm-svn: 317041

2 files changed, 5 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
index 7d50d643c99..67bab8c7684 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -154,11 +154,11 @@ StringRef CodeViewDebug::getFullFilepath(const DIFile *File) {
 }
 
 unsigned CodeViewDebug::maybeRecordFile(const DIFile *F) {
+  StringRef FullPath = getFullFilepath(F);
   unsigned NextId = FileIdMap.size() + 1;
-  auto Insertion = FileIdMap.insert(std::make_pair(F, NextId));
+  auto Insertion = FileIdMap.insert(std::make_pair(FullPath, NextId));
   if (Insertion.second) {
     // We have to compute the full filepath and emit a .cv_file directive.
-    StringRef FullPath = getFullFilepath(F);
     std::string Checksum = fromHex(F->getChecksum());
     void *CKMem = OS.getContext().allocate(Checksum.size(), 1);
     memcpy(CKMem, Checksum.data(), Checksum.size());
diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
index 5e424baf852..9eff4a7fd81 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.h
@@ -161,8 +161,9 @@ class LLVM_LIBRARY_VISIBILITY CodeViewDebug : public DebugHandlerBase {
   /// emit at the end of the TU.
   MapVector<const Function *, FunctionInfo> FnDebugInfo;
 
-  /// Map from DIFile to .cv_file id.
-  DenseMap<const DIFile *, unsigned> FileIdMap;
+  /// Map from full file path to .cv_file id. Full paths are built from DIFiles
+  /// and are stored in FileToFilepathMap;
+  DenseMap<StringRef, unsigned> FileIdMap;
 
   /// All inlined subprograms in the order they should be emitted.
   SmallSetVector<const DISubprogram *, 4> InlinedSubprograms;