From: Anders Carlsson <andersca@mac.com>
Date: Thu, 28 Jan 2010 18:22:03 +0000 (+0000)
Subject: Fix an incorrect union layout assert. Fixes PR6164.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=21fd7d7347358994ee6d944c22a51e82d22409d9;p=clang

Fix an incorrect union layout assert. Fixes PR6164.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@94754 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/CGRecordLayoutBuilder.cpp b/lib/CodeGen/CGRecordLayoutBuilder.cpp
index 9f90ec5ff6..cc474033c1 100644
--- a/lib/CodeGen/CGRecordLayoutBuilder.cpp
+++ b/lib/CodeGen/CGRecordLayoutBuilder.cpp
@@ -162,6 +162,8 @@ void CGRecordLayoutBuilder::LayoutUnion(const RecordDecl *D) {
   uint64_t Size = 0;
   unsigned Align = 0;
 
+  bool HasOnlyZeroSizedBitFields = true;
+  
   unsigned FieldNo = 0;
   for (RecordDecl::field_iterator Field = D->field_begin(),
        FieldEnd = D->field_end(); Field != FieldEnd; ++Field, ++FieldNo) {
@@ -181,6 +183,8 @@ void CGRecordLayoutBuilder::LayoutUnion(const RecordDecl *D) {
     } else
       Types.addFieldInfo(*Field, 0);
 
+    HasOnlyZeroSizedBitFields = false;
+    
     const llvm::Type *FieldTy =
       Types.ConvertTypeForMemRecursive(Field->getType());
     unsigned FieldAlign = Types.getTargetData().getABITypeAlignment(FieldTy);
@@ -207,7 +211,8 @@ void CGRecordLayoutBuilder::LayoutUnion(const RecordDecl *D) {
     }
   }
   if (!Align) {
-    assert((D->field_begin() == D->field_end()) && "LayoutUnion - Align 0");
+    assert(HasOnlyZeroSizedBitFields &&
+           "0-align record did not have all zero-sized bit-fields!");
     Align = 1;
   }
   
diff --git a/test/CodeGen/union.c b/test/CodeGen/union.c
index b40a405597..1883ca639b 100644
--- a/test/CodeGen/union.c
+++ b/test/CodeGen/union.c
@@ -39,3 +39,6 @@ int qfunc() {q buf; unsigned char* x = buf.x;}
 union RR {_Bool a : 1;} RRU;
 int RRF(void) {return RRU.a;}
 
+// PR6164
+typedef union T0 { unsigned int : 0; } T0;
+T0 t0;