akhuang updated this revision to Diff 556091.
akhuang added a comment.
add note to the docs about no ABI compatibility
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D157762/new/
https://reviews.llvm.org/D157762
Files:
clang/include/clang/Basic/Attr.td
clang/include/clang/Basic/AttrDocs.td
clang/lib/AST/Decl.cpp
clang/lib/AST/RecordLayoutBuilder.cpp
clang/lib/CodeGen/CGRecordLayoutBuilder.cpp
clang/lib/Sema/SemaDeclAttr.cpp
clang/test/Layout/ms-no-unique-address.cpp
Index: clang/test/Layout/ms-no-unique-address.cpp
===
--- /dev/null
+++ clang/test/Layout/ms-no-unique-address.cpp
@@ -0,0 +1,338 @@
+// RUN: %clang_cc1 -std=c++2a -fsyntax-only -triple x86_64-windows-msvc -fms-compatibility -fdump-record-layouts %s | FileCheck %s
+
+namespace Empty {
+ struct A {};
+ struct A2 {};
+ struct A3 { [[msvc::no_unique_address]] A a; };
+ struct alignas(8) A4 {};
+
+ struct B {
+[[msvc::no_unique_address]] A a;
+char b;
+ };
+ static_assert(sizeof(B) == 1);
+
+ // CHECK:*** Dumping AST Record Layout
+ // CHECK: 0 | struct Empty::B
+ // CHECK-NEXT: 0 | struct Empty::A a (empty)
+ // CHECK-NEXT: 0 | char b
+ // CHECK-NEXT: | [sizeof=1, align=1,
+ // CHECK-NEXT: | nvsize=1, nvalign=1]
+
+ struct C {
+[[msvc::no_unique_address]] A a;
+[[msvc::no_unique_address]] A2 a2;
+char c;
+ };
+ static_assert(sizeof(C) == 1);
+
+ // CHECK:*** Dumping AST Record Layout
+ // CHECK: 0 | struct Empty::C
+ // CHECK-NEXT: 0 | struct Empty::A a (empty)
+ // CHECK-NEXT: 0 | struct Empty::A2 a2 (empty)
+ // CHECK-NEXT: 0 | char c
+ // CHECK-NEXT: | [sizeof=1, align=1,
+ // CHECK-NEXT: | nvsize=1, nvalign=1]
+
+ struct D {
+[[msvc::no_unique_address]] A3 a;
+int i;
+ };
+ static_assert(sizeof(D) == 8);
+
+ // CHECK:*** Dumping AST Record Layout
+ // CHECK: 0 | struct Empty::D
+ // CHECK-NEXT: 0 | struct Empty::A3 a (empty)
+ // CHECK-NEXT: 0 | struct Empty::A a (empty)
+ // CHECK-NEXT: 4 | int i
+ // CHECK-NEXT: | [sizeof=8, align=4,
+ // CHECK-NEXT: | nvsize=8, nvalign=4]
+
+ struct E {
+[[msvc::no_unique_address]] A a1;
+[[msvc::no_unique_address]] A a2;
+char e;
+ };
+ static_assert(sizeof(E) == 2);
+
+ // CHECK:*** Dumping AST Record Layout
+ // CHECK: 0 | struct Empty::E
+ // CHECK-NEXT: 0 | struct Empty::A a1 (empty)
+ // CHECK-NEXT: 1 | struct Empty::A a2 (empty)
+ // CHECK-NEXT: 0 | char e
+ // CHECK-NEXT: | [sizeof=2, align=1,
+ // CHECK-NEXT: | nvsize=2, nvalign=1]
+
+ struct F {
+~F();
+[[msvc::no_unique_address]] A a1;
+[[msvc::no_unique_address]] A a2;
+char f;
+ };
+ static_assert(sizeof(F) == 2);
+
+ // CHECK:*** Dumping AST Record Layout
+ // CHECK: 0 | struct Empty::F
+ // CHECK-NEXT: 0 | struct Empty::A a1 (empty)
+ // CHECK-NEXT: 1 | struct Empty::A a2 (empty)
+ // CHECK-NEXT: 0 | char f
+ // CHECK-NEXT: | [sizeof=2, align=1,
+ // CHECK-NEXT: | nvsize=2, nvalign=1]
+
+ struct G { [[msvc::no_unique_address]] A a; ~G(); };
+ static_assert(sizeof(G) == 1);
+
+ // CHECK:*** Dumping AST Record Layout
+ // CHECK: 0 | struct Empty::G
+ // CHECK-NEXT: 0 | struct Empty::A a (empty)
+ // CHECK-NEXT: | [sizeof=1, align=1,
+ // CHECK-NEXT: | nvsize=1, nvalign=1]
+
+ struct H {
+[[msvc::no_unique_address]] A a;
+[[msvc::no_unique_address]] A b;
+~H();
+ };
+ static_assert(sizeof(H) == 2);
+
+ // CHECK:*** Dumping AST Record Layout
+ // CHECK: 0 | struct Empty::H
+ // CHECK-NEXT: 0 | struct Empty::A a (empty)
+ // CHECK-NEXT: 1 | struct Empty::A b (empty)
+ // CHECK-NEXT: | [sizeof=2, align=1,
+ // CHECK-NEXT: | nvsize=2, nvalign=1]
+
+ struct I {
+[[msvc::no_unique_address]] A4 a;
+[[msvc::no_unique_address]] A4 b;
+ };
+ static_assert(sizeof(I) == 16);
+
+ // CHECK:*** Dumping AST Record Layout
+ // CHECK: 0 | struct Empty::I
+ // CHECK-NEXT: 0 | struct Empty::A4 a (empty)
+ // CHECK-NEXT: 8 | struct Empty::A4 b (empty)
+ // CHECK-NEXT: | [sizeof=16, align=8,
+ // CHECK-NEXT: | nvsize=16, nvalign=8]
+
+ struct J {
+[[msvc::no_unique_address]] A4 a;
+A4 b;
+ };
+ static_assert(sizeof(J) == 16);
+
+ // MSVC puts a and b at the same offset.
+ // CHECK:*** Dumping AST Record Layout
+ // CHECK: 0 | struct Empty::J
+ // CHECK-NEXT: 0 | struct Empty::A4 a (empty)
+ // CHECK-NEXT: 8 | struct Empty::A4 b (empty)
+ // CHECK-NEXT: | [sizeof=16, align=8,
+ // CHECK-NEXT: | nvsize=16, nvalign=8]
+
+ struct K {
+[[msvc::no_unique_address]] A4 a;
+[[msvc::no_unique_address]] char c;
+[[msvc::no_unique_address]] A4 b;
+
