r283432 - [Sema] Fix PR30520: Handle incomplete field types in transparent_union unions

[Alex Lorenz via cfe-commits]

Author: arphaman
Date: Thu Oct  6 04:47:29 2016
New Revision: 283432

URL: http://llvm.org/viewvc/llvm-project?rev=283432&view=rev
Log:
[Sema] Fix PR30520: Handle incomplete field types in transparent_union unions

This commit fixes a crash that happens when clang is analyzing a
transparent_union attribute on a union which has a field with incomplete type.

rdar://28630028

Differential Revision: https://reviews.llvm.org/D25273

Modified:
    cfe/trunk/lib/Sema/SemaDeclAttr.cpp
    cfe/trunk/test/Sema/transparent-union.c

Modified: cfe/trunk/lib/Sema/SemaDeclAttr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclAttr.cpp?rev=283432&r1=283431&r2=283432&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclAttr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclAttr.cpp Thu Oct  6 04:47:29 2016
@@ -3044,10 +3044,14 @@ static void handleTransparentUnionAttr(S
     return;
   }
 
+  if (FirstType->isIncompleteType())
+    return;
   uint64_t FirstSize = S.Context.getTypeSize(FirstType);
   uint64_t FirstAlign = S.Context.getTypeAlign(FirstType);
   for (; Field != FieldEnd; ++Field) {
     QualType FieldType = Field->getType();
+    if (FieldType->isIncompleteType())
+      return;
     // FIXME: this isn't fully correct; we also need to test whether the
     // members of the union would all have the same calling convention as the
     // first member of the union. Checking just the size and alignment isn't

Modified: cfe/trunk/test/Sema/transparent-union.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/transparent-union.c?rev=283432&r1=283431&r2=283432&view=diff
==============================================================================
--- cfe/trunk/test/Sema/transparent-union.c (original)
+++ cfe/trunk/test/Sema/transparent-union.c Thu Oct  6 04:47:29 2016
@@ -89,3 +89,12 @@ union pr15134v2 {
     unsigned int u3;
   } __attribute__((aligned(8)));
 } __attribute__((transparent_union));
+
+union pr30520v { void b; } __attribute__((transparent_union)); // expected-error {{field has incomplete type 'void'}}
+
+union pr30520a { int b[]; } __attribute__((transparent_union)); // expected-error {{field has incomplete type 'int []'}}
+
+// expected-note at +1 2 {{forward declaration of 'struct stb'}}
+union pr30520s { struct stb b; } __attribute__((transparent_union)); // expected-error {{field has incomplete type 'struct stb'}}
+
+union pr30520s2 { int *v; struct stb b; } __attribute__((transparent_union)); // expected-error {{field has incomplete type 'struct stb'}}