DebugInfo: Avoid creating DILexicalScopeFiles when the filename in the current scope has not changed.

This looks like the right way for this check to work, but there is
another semi-obvious bug, I would think: why is CurLoc not zero'd out
between functions? The possibility for it to bleed between them seems
problematic. (& indeed I caused tests to fail when I fixed this a
different way, by setting CurLoc to SourceLocation() and the end of
EmitFunctionEnd... )

The changes to debug-info-blocks.m are due to a mismatch between the
source manager's file naming and CGDebugInfo's default handling when no
-main-file-name is specified. This actually reveals somewhat of a bug in
the debug info when using source files from standard in, too. See the
comment in CGDebugInfo::CreateCompileUnit for more details.

llvm-svn: 208742

1 files changed, 11 insertions, 7 deletions

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 4279e4985e8..acdce84e157 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -112,17 +112,14 @@ void CGDebugInfo::setLocation(SourceLocation Loc) {
   if (LexicalBlockStack.empty()) return;
 
   SourceManager &SM = CGM.getContext().getSourceManager();
+  llvm::DIScope Scope(LexicalBlockStack.back());
   PresumedLoc PCLoc = SM.getPresumedLoc(CurLoc);
-  PresumedLoc PPLoc = SM.getPresumedLoc(PrevLoc);
 
-  if (PCLoc.isInvalid() || PPLoc.isInvalid() ||
-      !strcmp(PPLoc.getFilename(), PCLoc.getFilename()))
+  if (PCLoc.isInvalid() || Scope.getFilename() == PCLoc.getFilename())
     return;
 
-  llvm::MDNode *LB = LexicalBlockStack.back();
-  llvm::DIScope Scope = llvm::DIScope(LB);
   if (Scope.isLexicalBlockFile()) {
-    llvm::DILexicalBlockFile LBF = llvm::DILexicalBlockFile(LB);
+    llvm::DILexicalBlockFile LBF = llvm::DILexicalBlockFile(Scope);
     llvm::DIDescriptor D
       = DBuilder.createLexicalBlockFile(LBF.getScope(),
                                         getOrCreateFile(CurLoc));
@@ -317,11 +314,18 @@ StringRef CGDebugInfo::getCurrentDirname() {
 /// CreateCompileUnit - Create new compile unit.
 void CGDebugInfo::CreateCompileUnit() {
 
+  // Should we be asking the SourceManager for the main file name, instead of
+  // accepting it as an argument? This just causes the main file name to
+  // mismatch with source locations and create extra lexical scopes or
+  // mismatched debug info (a CU with a DW_AT_file of "-", because that's what
+  // the driver passed, but functions/other things have DW_AT_file of "<stdin>"
+  // because that's what the SourceManager says)
+
   // Get absolute path name.
   SourceManager &SM = CGM.getContext().getSourceManager();
   std::string MainFileName = CGM.getCodeGenOpts().MainFileName;
   if (MainFileName.empty())
-    MainFileName = "<unknown>";
+    MainFileName = "<stdin>";
 
   // The main file name provided via the "-main-file-name" option contains just
   // the file name itself with no path information. This file name may have had