r311037 - Use the file name from linemarker for debug info if an input is preprocessed source.

[Taewook Oh via cfe-commits]

Author: twoh
Date: Wed Aug 16 12:36:24 2017
New Revision: 311037

URL: http://llvm.org/viewvc/llvm-project?rev=311037&view=rev
Log:
Use the file name from linemarker for debug info if an input is preprocessed source.

Summary:
Even in the case of the input file is a preprocessed source, clang uses the file name of the preprocesses source for debug info (DW_AT_name attribute for DW_TAG_compile_unit). However, gcc uses the file name specified in the first linemarker instead. This makes more sense because the one specified in the linemarker represents the "actual" source file name.

Clang already uses the file name specified in the first linemarker for Module name (https://github.com/llvm-mirror/clang/blob/master/lib/Frontend/FrontendAction.cpp#L779) if the input is preprocessed. This patch makes clang to use the same value for debug info as well.

Reviewers: compnerd, rnk, dblaikie, rsmith

Reviewed By: rnk

Subscribers: aprantl, cfe-commits

Differential Revision: https://reviews.llvm.org/D36474

Added:
    cfe/trunk/test/CodeGen/debug-info-preprocessed-file.i
Modified:
    cfe/trunk/lib/CodeGen/CGDebugInfo.cpp

Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.cpp?rev=311037&r1=311036&r2=311037&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGDebugInfo.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGDebugInfo.cpp Wed Aug 16 12:36:24 2017
@@ -29,6 +29,7 @@
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/Version.h"
 #include "clang/Frontend/CodeGenOptions.h"
+#include "clang/Frontend/FrontendOptions.h"
 #include "clang/Lex/HeaderSearchOptions.h"
 #include "clang/Lex/ModuleMap.h"
 #include "clang/Lex/PreprocessorOptions.h"
@@ -495,6 +496,16 @@ void CGDebugInfo::CreateCompileUnit() {
       llvm::sys::path::append(MainFileDirSS, MainFileName);
       MainFileName = MainFileDirSS.str();
     }
+    // If the main file name provided is identical to the input file name, and
+    // if the input file is a preprocessed source, use the module name for
+    // debug info. The module name comes from the name specified in the first
+    // linemarker if the input is a preprocessed source.
+    if (MainFile->getName() == MainFileName &&
+        FrontendOptions::getInputKindForExtension(
+            MainFile->getName().rsplit('.').second)
+            .isPreprocessed())
+      MainFileName = CGM.getModule().getName().str();
+
     CSKind = computeChecksum(SM.getMainFileID(), Checksum);
   }
 

Added: cfe/trunk/test/CodeGen/debug-info-preprocessed-file.i
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/debug-info-preprocessed-file.i?rev=311037&view=auto
==============================================================================
--- cfe/trunk/test/CodeGen/debug-info-preprocessed-file.i (added)
+++ cfe/trunk/test/CodeGen/debug-info-preprocessed-file.i Wed Aug 16 12:36:24 2017
@@ -0,0 +1,11 @@
+# 1 "/foo/bar/preprocessed-input.c"
+# 1 "<built-in>" 1
+# 1 "<built-in>" 3
+# 318 "<built-in>" 3
+# 1 "<command line>" 1
+# 1 "<built-in>" 2
+# 1 "preprocessed-input.c" 2
+
+// RUN: %clang -g -c -S -emit-llvm -o - %s | FileCheck %s
+// CHECK: !DICompileUnit(language: DW_LANG_C99, file: ![[FILE:[0-9]+]] 
+// CHECK: ![[FILE]] = !DIFile(filename: "/foo/bar/preprocessed-input.c"