From: Devang Patel <dpatel@apple.com>
Date: Thu, 23 Apr 2009 18:09:16 +0000 (+0000)
Subject: Handle corner case where clang-cc is invoked directly to compile preprocessed source... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=87de6497f45243fbcef6dac5be6a641ca9331f61;p=clang

Handle corner case where clang-cc is invoked directly to compile preprocessed source file without -main-file-name. In this case, CDDebugInfo is not able identify correct main source file becase SM.isFromMainFile() returns true for locations from header files as well as locations from main source file.
This patch takes conservative approach by not emitting more then one compile unit with isMain bit set.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69902 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index f2ca2e7c58..a652ede1c1 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -34,7 +34,7 @@ using namespace clang;
 using namespace clang::CodeGen;
 
 CGDebugInfo::CGDebugInfo(CodeGenModule *m)
-  : M(m), DebugFactory(M->getModule()) {
+  : M(m), isMainCompileUnitCreated(false), DebugFactory(M->getModule()) {
 }
 
 CGDebugInfo::~CGDebugInfo() {
@@ -71,16 +71,22 @@ llvm::DICompileUnit CGDebugInfo::getOrCreateCompileUnit(SourceLocation Loc) {
     AbsFileName = tmp;
   }
 
-  // See if thie compile unit is represnting main source file.
+  // See if thie compile unit is representing main source file. Each source
+  // file has corresponding compile unit. There is only one main source
+  // file at a time.
   bool isMain = false;
   const LangOptions &LO = M->getLangOptions();
   const char *MainFileName = LO.getMainFileName();
-  if (MainFileName) {
-    if (!strcmp(AbsFileName.getLast().c_str(), MainFileName))
-      isMain = true;
-  } else {
-    if (Loc.isValid() && SM.isFromMainFile(Loc))
-      isMain = true;
+  if (isMainCompileUnitCreated == false) {
+    if (MainFileName) {
+      if (!strcmp(AbsFileName.getLast().c_str(), MainFileName))
+        isMain = true;
+    } else {
+      if (Loc.isValid() && SM.isFromMainFile(Loc))
+        isMain = true;
+    }
+    if (isMain)
+      isMainCompileUnitCreated = true;
   }
 
   unsigned LangTag;
diff --git a/lib/CodeGen/CGDebugInfo.h b/lib/CodeGen/CGDebugInfo.h
index 4a59ecaaa5..1581637f4a 100644
--- a/lib/CodeGen/CGDebugInfo.h
+++ b/lib/CodeGen/CGDebugInfo.h
@@ -34,6 +34,7 @@ namespace CodeGen {
 /// the backend.
 class CGDebugInfo {
   CodeGenModule *M;
+  bool isMainCompileUnitCreated;
   llvm::DIFactory DebugFactory;
   
   SourceLocation CurLoc, PrevLoc;
diff --git a/test/CodeGen/2009-04-23-dbg.c b/test/CodeGen/2009-04-23-dbg.c
new file mode 100644
index 0000000000..4be6dab7ea
--- /dev/null
+++ b/test/CodeGen/2009-04-23-dbg.c
@@ -0,0 +1,20 @@
+// RUN: clang-cc -g -o %t  %s -emit-llvm-bc && llc %t -f -o %t.s
+# 1 "a.c"
+# 1 "a.c" 1
+# 1 "<built-in>" 1
+# 103 "<built-in>"
+# 103 "<command line>" 1
+
+# 1 "/private/tmp/a.h" 1
+int bar;
+# 105 "<command line>" 2
+# 105 "<built-in>" 2
+# 1 "a.c" 2
+# 1 "/private/tmp/a.h" 1
+int bar;
+# 2 "a.c" 2
+
+int main() {
+ bar = 0;
+ return 0;
+}