Downgrade errors when trying to catch a pointer or reference to

incomplete type to warnings; GCC (and EDG in GCC compatibility mode)
permit such handles. Fixes PR6527.

(For real this time)

llvm-svn: 97927

1 files changed, 10 insertions, 3 deletions

diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index e32d14e1c87..a89f355147f 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -5195,21 +5195,28 @@ VarDecl *Sema::BuildExceptionDeclaration(Scope *S, QualType ExDeclType,
     Invalid = true;
   }
 
+  // GCC allows catching pointers and references to incomplete types
+  // as an extension; so do we, but we warn by default.
+
   QualType BaseType = ExDeclType;
   int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference
   unsigned DK = diag::err_catch_incomplete;
+  bool IncompleteCatchIsInvalid = true;
   if (const PointerType *Ptr = BaseType->getAs<PointerType>()) {
     BaseType = Ptr->getPointeeType();
     Mode = 1;
-    DK = diag::err_catch_incomplete_ptr;
+    DK = diag::ext_catch_incomplete_ptr;
+    IncompleteCatchIsInvalid = false;
   } else if (const ReferenceType *Ref = BaseType->getAs<ReferenceType>()) {
     // For the purpose of error recovery, we treat rvalue refs like lvalue refs.
     BaseType = Ref->getPointeeType();
     Mode = 2;
-    DK = diag::err_catch_incomplete_ref;
+    DK = diag::ext_catch_incomplete_ref;
+    IncompleteCatchIsInvalid = false;
   }
   if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) &&
-      !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK))
+      !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK) &&
+      IncompleteCatchIsInvalid)
     Invalid = true;
 
   if (!Invalid && !ExDeclType->isDependentType() &&