PR16214, PR14467: DebugInfo: use "RequireCompleteType" to decide when to emit the full definition of a type in -flimit-debug-info

This simplifies the core benefit of -flimit-debug-info by taking a more
systematic approach to avoid emitting debug info definitions for types
that only require declarations. The previous ad-hoc approach (3 cases
removed in this patch) had many holes.

The general approach (adding a bit to TagDecl and callback through
ASTConsumer) has been discussed with Richard Smith - though always open
to revision.

llvm-svn: 186262

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/ModuleBuilder.cpp b/clang/lib/CodeGen/ModuleBuilder.cpp
index 763aa12aab1..7e0e3aac072 100644
--- a/clang/lib/CodeGen/ModuleBuilder.cpp
+++ b/clang/lib/CodeGen/ModuleBuilder.cpp
@@ -13,6 +13,7 @@
 
 #include "clang/CodeGen/ModuleBuilder.h"
 #include "CodeGenModule.h"
+#include "CGDebugInfo.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/Expr.h"
@@ -93,6 +94,12 @@ namespace {
       }
     }
 
+    virtual void HandleTagDeclRequiredDefinition(const TagDecl *D) LLVM_OVERRIDE {
+      if (CodeGen::CGDebugInfo *DI = Builder->getModuleDebugInfo())
+        if (const RecordDecl *RD = dyn_cast<RecordDecl>(D))
+          DI->completeFwdDecl(*RD);
+    }
+
     virtual void HandleTranslationUnit(ASTContext &Ctx) {
       if (Diags.hasErrorOccurred()) {
         M.reset();