From: Alex Lorenz <arphaman@gmail.com>
Date: Thu, 6 Oct 2016 09:47:29 +0000 (+0000)
Subject: [Sema] Fix PR30520: Handle incomplete field types in transparent_union unions
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d9e3029d1906f2991bd7a17282002ee6f3144e16;p=clang

[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


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@283432 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index e06f110f0e..3e8a39a578 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -3044,10 +3044,14 @@ static void handleTransparentUnionAttr(Sema &S, Decl *D,
     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
diff --git a/test/Sema/transparent-union.c b/test/Sema/transparent-union.c
index 8ef70bb1c7..a1a67dfd26 100644
--- a/test/Sema/transparent-union.c
+++ b/test/Sema/transparent-union.c
@@ -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@+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'}}