llvm-project/clang/test/CodeGenCXX/microsoft-uuidof.cpp
Richard Smith bab6df86ae Rework how UuidAttr, CXXUuidofExpr, and GUID template arguments and constants are represented.
Summary:
Previously, we treated CXXUuidofExpr as quite a special case: it was the
only kind of expression that could be a canonical template argument, it
could be a constant lvalue base object, and so on. In addition, we
represented the UUID value as a string, whose source form we did not
preserve faithfully, and that we partially parsed in multiple different
places.

With this patch, we create an MSGuidDecl object to represent the
implicit object of type 'struct _GUID' created by a UuidAttr. Each
UuidAttr holds a pointer to its 'struct _GUID' and its original
(as-written) UUID string. A non-value-dependent CXXUuidofExpr behaves
like a DeclRefExpr denoting that MSGuidDecl object. We cache an APValue
representation of the GUID on the MSGuidDecl and use it from constant
evaluation where needed.

This allows removing a lot of the special-case logic to handle these
expressions. Unfortunately, many parts of Clang assume there are only
a couple of interesting kinds of ValueDecl, so the total amount of
special-case logic is not really reduced very much.

This fixes a few bugs and issues:
 * PR38490: we now support reading from GUID objects returned from
   __uuidof during constant evaluation.
 * Our Itanium mangling for a non-instantiation-dependent template
   argument involving __uuidof no longer depends on which CXXUuidofExpr
   template argument we happened to see first.
 * We now predeclare ::_GUID, and permit use of __uuidof without
   any header inclusion, better matching MSVC's behavior. We do not
   predefine ::__s_GUID, though; that seems like a step too far.
 * Our IR representation for GUID constants now uses the correct IR type
   wherever possible. We will still fall back to using the
      {i32, i16, i16, [8 x i8]}
   layout if a definition of struct _GUID is not available. This is not
   ideal: in principle the two layouts could have different padding.

Reviewers: rnk, jdoerfert

Subscribers: arphaman, cfe-commits, aeubanks

Tags: #clang

Differential Revision: https://reviews.llvm.org/D78171
2020-04-15 12:20:42 -07:00

140 lines
8.5 KiB
C++

// RUN: %clang_cc1 -emit-llvm %s -o - -DDEFINE_GUID -triple=i386-pc-linux -fms-extensions | FileCheck %s --check-prefix=CHECK-DEFINE-GUID
// RUN: %clang_cc1 -emit-llvm %s -o - -DDEFINE_GUID -DBRACKET_ATTRIB -triple=i386-pc-linux -fms-extensions | FileCheck %s --check-prefix=CHECK-DEFINE-GUID
// RUN: %clang_cc1 -emit-llvm %s -o - -triple=i386-pc-linux -fms-extensions | FileCheck %s
// RUN: %clang_cc1 -emit-llvm %s -o - -triple=x86_64-pc-linux -fms-extensions | FileCheck %s --check-prefix=CHECK-64
// RUN: %clang_cc1 -emit-llvm %s -o - -DDEFINE_GUID -DWRONG_GUID -triple=i386-pc-linux -fms-extensions | FileCheck %s --check-prefix=CHECK-DEFINE-WRONG-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];
#endif
};
#endif
typedef struct _GUID GUID;
#ifdef BRACKET_ATTRIB
[uuid(12345678-1234-1234-1234-1234567890aB)] struct S1 { } s1;
[uuid(87654321-4321-4321-4321-ba0987654321)] struct S2 { };
[uuid({12345678-1234-1234-1234-1234567890ac})] struct Curly;
[uuid({12345678-1234-1234-1234-1234567890ac})] struct Curly;
#else
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;
struct __declspec(uuid("{12345678-1234-1234-1234-1234567890ac}")) Curly;
#endif
void side_effect();
#ifdef DEFINE_GUID
// Make sure we can properly generate code when the UUID has curly braces on it.
GUID thing = (side_effect(), __uuidof(Curly));
// 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-DEFINE-GUID: @g = global %struct._GUID zeroinitializer, align 4
// CHECK-DEFINE-WRONG-GUID: @g = global %struct._GUID zeroinitializer, align 4
GUID g = (side_effect(), __uuidof(S1));
// CHECK-DEFINE-GUID: @const_init = global %struct._GUID { i32 305419896, i16 4660, i16 4660, [8 x i8] c"\124\124Vx\90\AC" }
// CHECK-DEFINE-WRONG-GUID: @const_init = global %struct._GUID zeroinitializer
GUID const_init = __uuidof(Curly);
#endif
// First global use of __uuidof(S1) forces the creation of the global.
// CHECK: @_GUID_12345678_1234_1234_1234_1234567890ab = linkonce_odr constant { i32, i16, i16, [8 x i8] } { i32 305419896, i16 4660, i16 4660, [8 x i8] c"\124\124Vx\90\AB" }, comdat
// CHECK: @gr = constant %struct._GUID* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to %struct._GUID*), align 4
// CHECK-64: @gr = constant %struct._GUID* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to %struct._GUID*), align 8
const GUID& gr = __uuidof(S1);
// 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* 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* 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 = linkonce_odr constant { i32, i16, i16, [8 x i8] } { i32 -2023406815, i16 17185, i16 17185, [8 x i8] c"C!\BA\09\87eC!" }, comdat
// The static initializer for thing.
// CHECK-DEFINE-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 bitcast (%struct._GUID* @thing to i8*), i8* align 4 bitcast (%struct._GUID* @_GUID_12345678_1234_1234_1234_1234567890ac to i8*), i32 16, i1 false)
// CHECK-DEFINE-WRONG-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 bitcast (%struct._GUID* @thing to i8*), i8* align 4 bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ac to i8*), i32 4, i1 false)
// The static initializer for g.
// CHECK-DEFINE-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 bitcast (%struct._GUID* @g to i8*), i8* align 4 bitcast (%struct._GUID* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 16, i1 false)
// CHECK-DEFINE-WRONG-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 bitcast (%struct._GUID* @g to i8*), i8* align 4 bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 4, i1 false)
// We don't constant-initialize const_init if the definition of _GUID is dodgy.
// CHECK-DEFINE-GUID-NOT: @const_init
// CHECK-DEFINE-WRONG-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 bitcast (%struct._GUID* @const_init to i8*), i8* align 4 bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ac to i8*), i32 4, i1 false)
#ifdef DEFINE_GUID
void fun() {
// 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* align 4 [[U1]], i8* align 4 bitcast (%struct._GUID* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 16, i1 false)
// CHECK-DEFINE-WRONG-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 [[U1]], i8* align 4 bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 4, i1 false)
GUID s1_1 = (side_effect(), __uuidof(S1));
// 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* align 4 [[U2]], i8* align 4 bitcast (%struct._GUID* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 16, i1 false)
// CHECK-DEFINE-WRONG-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 [[U2]], i8* align 4 bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 4, i1 false)
GUID s1_2 = (side_effect(), __uuidof(S1));
// 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* align 4 [[U3]], i8* align 4 bitcast (%struct._GUID* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 16, i1 false)
// CHECK-DEFINE-WRONG-GUID: call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 4 [[U3]], i8* align 4 bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to i8*), i32 4, i1 false)
GUID s1_3 = (side_effect(), __uuidof(s1));
}
#endif
void gun() {
#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
// 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* 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* 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);
}
namespace DeclRefExprNamingGUID {
template<const _GUID &g> const _GUID &f() { return g; }
struct __declspec(uuid("12345678-1234-1234-1234-123412341234")) S {};
auto &r = f<__uuidof(S)>();
}