CodeGen: __uuidof should work even with an incomplete _GUID type

Summary:
We would crash in CodeGen::CodeGenModule::EmitUuidofInitializer
because our attempt to enter CodeGen::CodeGenModule::EmitConstantValue
will be foiled: the type of the constant value is incomplete.

Instead, create an unnamed type with the proper layout on all platforms.
Punt the problem of wrongly defined struct _GUID types to the user.
(It's impossible because the TU may never get to see the type and thus
we can't verify that it is suitable.)

This fixes PR16856.

Reviewers: rsmith, rnk, thakis

Reviewed By: rnk

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1375

llvm-svn: 188481

1 files changed, 61 insertions, 29 deletions

diff --git a/clang/test/CodeGenCXX/microsoft-uuidof.cpp b/clang/test/CodeGenCXX/microsoft-uuidof.cpp
index 38ffafc0074..75b77b256b9 100644
--- a/clang/test/CodeGenCXX/microsoft-uuidof.cpp
+++ b/clang/test/CodeGenCXX/microsoft-uuidof.cpp
@@ -1,80 +1,112 @@
+// RUN: %clang_cc1 -emit-llvm %s -o - -DDEFINE_GUID -triple=i386-pc-win32 -fms-extensions | FileCheck %s --check-prefix=CHECK-DEFINE-GUID
 // RUN: %clang_cc1 -emit-llvm %s -o - -triple=i386-pc-win32 -fms-extensions | FileCheck %s
+// RUN: %clang_cc1 -emit-llvm %s -o - -DDEFINE_GUID -DWRONG_GUID -triple=i386-pc-win32 -fms-extensions | FileCheck %s --check-prefix=CHECK-DEFINE-WRONG-GUID
 
-typedef struct _GUID
-{
+#ifdef DEFINE_GUID
+struct _GUID {
+#ifdef WRONG_GUID
+    unsigned int SomethingWentWrong;
+#else
     unsigned long  Data1;
     unsigned short Data2;
     unsigned short Data3;
     unsigned char  Data4[8];
-} GUID;
+#endif
+};
+#endif
+typedef struct _GUID GUID;
 
 struct __declspec(uuid("12345678-1234-1234-1234-1234567890aB")) S1 { } s1;
 struct __declspec(uuid("87654321-4321-4321-4321-ba0987654321")) S2 { };
 struct __declspec(uuid("{12345678-1234-1234-1234-1234567890ac}")) Curly;
 
+#ifdef DEFINE_GUID
 // Make sure we can properly generate code when the UUID has curly braces on it.
 GUID thing = __uuidof(Curly);
-// CHECK: @thing = global %struct._GUID zeroinitializer, align 4
+// CHECK-DEFINE-GUID: @thing = global %struct._GUID zeroinitializer, align 4
+// CHECK-DEFINE-WRONG-GUID: @thing = global %struct._GUID zeroinitializer, align 4
 
 // This gets initialized in a static initializer.
-// CHECK: @g = global %struct._GUID zeroinitializer, align 4
+// CHECK-DEFINE-GUID: @g = global %struct._GUID zeroinitializer, align 4
+// CHECK-DEFINE-WRONG-GUID: @g = global %struct._GUID zeroinitializer, align 4
 GUID g = __uuidof(S1);
+#endif
 
 // First global use of __uuidof(S1) forces the creation of the global.
-// CHECK: @_GUID_12345678_1234_1234_1234_1234567890ab = unnamed_addr constant %struct._GUID { i32 305419896, i16 4660, i16 4660, [8 x i8] c"\124\124Vx\90\AB" }
-// CHECK: @gr = constant %struct._GUID* @_GUID_12345678_1234_1234_1234_1234567890ab, align 4
+// CHECK: @_GUID_12345678_1234_1234_1234_1234567890ab = constant { i32, i16, i16, [8 x i8] } { i32 305419896, i16 4660, i16 4660, [8 x i8] c"\124\124Vx\90\AB" }
+// CHECK: @gr = constant %struct._GUID* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to %struct._GUID*), align 4
 const GUID& gr = __uuidof(S1);
 
-// CHECK: @gp = global %struct._GUID* @_GUID_12345678_1234_1234_1234_1234567890ab, align 4
+// CHECK: @gp = global %struct._GUID* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to %struct._GUID*), align 4
 const GUID* gp = &__uuidof(S1);
 
-// CHECK: @cp = global %struct._GUID* @_GUID_12345678_1234_1234_1234_1234567890ac, align 4
+// CHECK: @cp = global %struct._GUID* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ac to %struct._GUID*), align 4
 const GUID* cp = &__uuidof(Curly);
 
 // Special case: _uuidof(0)
-// CHECK: @zeroiid = constant %struct._GUID* @_GUID_00000000_0000_0000_0000_000000000000, align 4
+// CHECK: @zeroiid = constant %struct._GUID* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_00000000_0000_0000_0000_000000000000 to %struct._GUID*), align 4
 const GUID& zeroiid = __uuidof(0);
 
 // __uuidof(S2) hasn't been used globally yet, so it's emitted when it's used
 // in a function and is emitted at the end of the globals section.
-// CHECK: @_GUID_87654321_4321_4321_4321_ba0987654321 = unnamed_addr constant %struct._GUID { i32 -2023406815, i16 17185, i16 17185, [8 x i8] c"C!\BA\09\87eC!" }
+// CHECK: @_GUID_87654321_4321_4321_4321_ba0987654321 = constant { i32, i16, i16, [8 x i8] } { i32 -2023406815, i16 17185, i16 17185, [8 x i8] c"C!\BA\09\87eC!" }
+
+// The static initializer for thing.
+// CHECK-DEFINE-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* bitcast (%struct._GUID* @thing to i8*), i8* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ac to i8*), i32 16, i32 4, i1 false)
+// CHECK-DEFINE-WRONG-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* bitcast (%struct._GUID* @thing to i8*), i8* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ac to i8*), i32 4, i32 4, i1 false)
 
 // The static initializer for g.
-// CHECK: call void @llvm.memcpy.p0i8.p0i8.i32(i8* bitcast (%struct._GUID* @g to i8*), i8* bitcast (%struct._GUID* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 16, i32 4, i1 false)
+// CHECK-DEFINE-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* bitcast (%struct._GUID* @g to i8*), i8* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 16, i32 4, i1 false)
+// CHECK-DEFINE-WRONG-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* bitcast (%struct._GUID* @g to i8*), i8* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 4, i32 4, i1 false)
 
+#ifdef DEFINE_GUID
 void fun() {
-  // CHECK: %s1_1 = alloca %struct._GUID, align 4
-  // CHECK: %s1_2 = alloca %struct._GUID, align 4
-  // CHECK: %s1_3 = alloca %struct._GUID, align 4
-
-  // CHECK: [[U1:%.+]] = bitcast %struct._GUID* %s1_1 to i8*
-  // CHECK: call void @llvm.memcpy.p0i8.p0i8.i32(i8* [[U1]], i8* bitcast (%struct._GUID* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 16, i32 4, i1 false)
+  // CHECK-DEFINE-GUID: %s1_1 = alloca %struct._GUID, align 4
+  // CHECK-DEFINE-WRONG-GUID: %s1_1 = alloca %struct._GUID, align 4
+  // CHECK-DEFINE-GUID: %s1_2 = alloca %struct._GUID, align 4
+  // CHECK-DEFINE-WRONG-GUID: %s1_2 = alloca %struct._GUID, align 4
+  // CHECK-DEFINE-GUID: %s1_3 = alloca %struct._GUID, align 4
+  // CHECK-DEFINE-WRONG-GUID: %s1_3 = alloca %struct._GUID, align 4
+
+  // CHECK-DEFINE-GUID: [[U1:%.+]] = bitcast %struct._GUID* %s1_1 to i8*
+  // CHECK-DEFINE-WRONG-GUID: [[U1:%.+]] = bitcast %struct._GUID* %s1_1 to i8*
+  // CHECK-DEFINE-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* [[U1]], i8* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 16, i32 4, i1 false)
+  // CHECK-DEFINE-WRONG-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* [[U1]], i8* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 4, i32 4, i1 false)
   GUID s1_1 = __uuidof(S1);
 
-  // CHECK: [[U2:%.+]] = bitcast %struct._GUID* %s1_2 to i8*
-  // CHECK: call void @llvm.memcpy.p0i8.p0i8.i32(i8* [[U2]], i8* bitcast (%struct._GUID* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 16, i32 4, i1 false)
+  // CHECK-DEFINE-GUID: [[U2:%.+]] = bitcast %struct._GUID* %s1_2 to i8*
+  // CHECK-DEFINE-WRONG-GUID: [[U2:%.+]] = bitcast %struct._GUID* %s1_2 to i8*
+  // CHECK-DEFINE-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* [[U2]], i8* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 16, i32 4, i1 false)
+  // CHECK-DEFINE-WRONG-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* [[U2]], i8* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 4, i32 4, i1 false)
   GUID s1_2 = __uuidof(S1);
 
-  // CHECK: [[U3:%.+]] = bitcast %struct._GUID* %s1_3 to i8*
-  // CHECK: call void @llvm.memcpy.p0i8.p0i8.i32(i8* [[U3]], i8* bitcast (%struct._GUID* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 16, i32 4, i1 false)
+  // CHECK-DEFINE-GUID: [[U3:%.+]] = bitcast %struct._GUID* %s1_3 to i8*
+  // CHECK-DEFINE-WRONG-GUID: [[U3:%.+]] = bitcast %struct._GUID* %s1_3 to i8*
+  // CHECK-DEFINE-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* [[U3]], i8* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 16, i32 4, i1 false)
+  // CHECK-DEFINE-WRONG-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* [[U3]], i8* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 4, i32 4, i1 false)
   GUID s1_3 = __uuidof(s1);
 }
+#endif
 
 void gun() {
-  // CHECK: %s2_1 = alloca %struct._GUID, align 4
-  // CHECK: %s2_2 = alloca %struct._GUID, align 4
+#ifdef DEFINE_GUID
+  // CHECK-DEFINE-GUID: %s2_1 = alloca %struct._GUID, align 4
+  // CHECK-DEFINE-WRONG-GUID: %s2_1 = alloca %struct._GUID, align 4
+  // CHECK-DEFINE-GUID: %s2_2 = alloca %struct._GUID, align 4
+  // CHECK-DEFINE-WRONG-GUID: %s2_2 = alloca %struct._GUID, align 4
+  GUID s2_1 = __uuidof(S2);
+  GUID s2_2 = __uuidof(S2);
+#endif
   // CHECK: %r = alloca %struct._GUID*, align 4
   // CHECK: %p = alloca %struct._GUID*, align 4
   // CHECK: %zeroiid = alloca %struct._GUID*, align 4
-  GUID s2_1 = __uuidof(S2);
-  GUID s2_2 = __uuidof(S2);
 
-  // CHECK: store %struct._GUID* @_GUID_87654321_4321_4321_4321_ba0987654321, %struct._GUID** %r, align 4
+  // CHECK: store %struct._GUID* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_87654321_4321_4321_4321_ba0987654321 to %struct._GUID*), %struct._GUID** %r, align 4
   const GUID& r = __uuidof(S2);
-  // CHECK: store %struct._GUID* @_GUID_87654321_4321_4321_4321_ba0987654321, %struct._GUID** %p, align 4
+  // CHECK: store %struct._GUID* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_87654321_4321_4321_4321_ba0987654321 to %struct._GUID*), %struct._GUID** %p, align 4
   const GUID* p = &__uuidof(S2);
 
   // Special case _uuidof(0), local scope version.
-  // CHECK: store %struct._GUID* @_GUID_00000000_0000_0000_0000_000000000000, %struct._GUID** %zeroiid, align 4
+  // CHECK: store %struct._GUID* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_00000000_0000_0000_0000_000000000000 to %struct._GUID*), %struct._GUID** %zeroiid, align 4
   const GUID& zeroiid = __uuidof(0);
 }