Allow creation of "dummy" compile units for debug information.

 - Although gross, this is needed currently to ensure that we produce
   well formed debug information (to match pace with the assertions
   being added to DebugInfo in LLVM).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62734 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 29 insertions, 10 deletions

diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index d3fee11e46..e0a52d6184 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -47,21 +47,24 @@ void CGDebugInfo::setLocation(SourceLocation Loc) {
 /// getOrCreateCompileUnit - Get the compile unit from the cache or create a new
 /// one if necessary. This returns null for invalid source locations.
 llvm::DICompileUnit CGDebugInfo::getOrCreateCompileUnit(SourceLocation Loc) {
-  if (Loc.isInvalid())
-    return llvm::DICompileUnit();
-
-  SourceManager &SM = M->getContext().getSourceManager();
-  Loc = SM.getInstantiationLoc(Loc);
-  const FileEntry *FE = SM.getFileEntryForID(SM.getFileID(Loc));
-  if (FE == 0) return llvm::DICompileUnit();
-    
+  // FIXME: Until we do a complete job of emitting debug information,
+  // we need to support making dummy compile units so that we generate
+  // "well formed" debug info.
+  const FileEntry *FE = 0;
+
+  if (Loc.isValid()) {
+    SourceManager &SM = M->getContext().getSourceManager();
+    Loc = SM.getInstantiationLoc(Loc);
+    FE = SM.getFileEntryForID(SM.getFileID(Loc));
+  }
+   
   // See if this compile unit has been used before.
   llvm::DICompileUnit &Unit = CompileUnitCache[FE];
   if (!Unit.isNull()) return Unit;
   
   // Get source file information.
-  const char *FileName = FE->getName();
-  const char *DirName = FE->getDir()->getName();
+  const char *FileName = FE ? FE->getName() : "<unknown>";
+  const char *DirName = FE ? FE->getDir()->getName() : "";
   
   // Create new compile unit.
   // FIXME: Handle other language IDs as well.
diff --git a/test/CodeGen/2009-01-21-invalid-debug-info.m b/test/CodeGen/2009-01-21-invalid-debug-info.m
new file mode 100644
index 0000000000..509a6fb4ed
--- /dev/null
+++ b/test/CodeGen/2009-01-21-invalid-debug-info.m
@@ -0,0 +1,16 @@
+// RUN: clang -S -g -o %t.s %s
+
+// FIXME: This test case can be removed at some point (since it will
+// no longer effectively test anything). The reason it was causing
+// trouble was the synthesized self decl in im1 was causing the debug
+// info for I1* to be generated, but referring to an invalid compile
+// unit. This was later referred to by f1 and created ill formed debug
+// information.
+
+@interface I1 @end
+
+@implementation I1
+-im0 {}
+@end
+
+I1 *f1(void) { return 0; }