Add some comments to r184252.

rdar://problem/14101097

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184259 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index a5e9e4e092e6ce0b9c508c81765f26cd7fe7e9dc..563faa4f7804bd2a93cbdb1b065871efadf361ed 100644 (file)
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -1379,7 +1379,12 @@ llvm::DIType CGDebugInfo::getOrCreateInterfaceType(QualType D,
 /// CreateType - get structure or union type.
 llvm::DIType CGDebugInfo::CreateType(const RecordType *Ty, bool Declaration) {
   RecordDecl *RD = Ty->getDecl();
+  // Limited debug info should only remove struct definitions that can
+  // safely be replaced by a forward declaration in the source code.
   if (DebugKind <= CodeGenOptions::LimitedDebugInfo && Declaration) {
+    // FIXME: This implementation is problematic; there are some test
+    // cases where we violate the above principle, such as
+    // test/CodeGen/debug-info-records.c .
     llvm::DIDescriptor FDContext =
       getContextDescriptor(cast<Decl>(RD->getDeclContext()));
     llvm::DIType RetTy = createRecordFwdDecl(RD, FDContext);

diff --git a/test/CodeGen/debug-info-record.c b/test/CodeGen/debug-info-record.c
index 01e3c109880e39835c97a11915b11d0b249e3375..55927ca667ae73104b474b30dd47b165994f937b 100644 (file)
--- a/test/CodeGen/debug-info-record.c
+++ b/test/CodeGen/debug-info-record.c
@@ -3,7 +3,9 @@
 // rdar://problem/14101097
 //
 // FIXME: This should work with -flimit-debug-info, too.
-//
+
+// Make sure this is not a forward declaration.
+// CHECK-NOT: [ DW_TAG_structure_type ] [elusive_s] {{.*}} [fwd]
 // CHECK: [ DW_TAG_member ] [foo]
 // CHECK: [ DW_TAG_member ] [bar]
 struct elusive_s {
@@ -16,4 +18,3 @@ int baz(void* x) {
   elusive_t s = x;
   return s->foo;
 }
-