clang/test/CXX/dcl.dcl/dcl.attr/dcl.align/p5.cpp

   1 // RUN: %clang_cc1 -std=c++11 -triple x86_64-linux-gnu -verify %s
   2
   3 alignas(1) int n1; // expected-error {{requested alignment is less than minimum alignment of 4 for type 'int'}}
   4 alignas(1) alignas(2) int n2; // expected-error {{less than minimum alignment}}
   5 alignas(1) alignas(2) alignas(4) int n3; // ok
   6 alignas(1) alignas(2) alignas(0) int n4; // expected-error {{less than minimum alignment}}
   7 alignas(1) alignas(2) int n5 alignas(4); // ok
   8 alignas(1) alignas(4) int n6 alignas(2); // ok
   9 alignas(1) int n7 alignas(2), // expected-error {{less than minimum alignment}}
  10                n8 alignas(4); // ok
  11 alignas(8) int n9 alignas(2); // ok, overaligned
  12 alignas(1) extern int n10; // expected-error {{less than minimum alignment}}
  13
  14 typedef __attribute__((aligned(16))) int IntAlign16;
  15 enum E6 : IntAlign16 {};
  16 static_assert(alignof(E6) == 4, "");
  17
  18 struct S1 {
  19   alignas(8) int n;
  20 };
  21 struct alignas(2) S2 { // expected-error {{requested alignment is less than minimum alignment of 4 for type 'S2'}}
  22   int n;
  23 };
  24 struct alignas(2) S3 { // expected-error {{requested alignment is less than minimum alignment of 8 for type 'S3'}}
  25   S1 s1;
  26 };
  27 struct alignas(2) S4 : S1 { // expected-error {{requested alignment is less than minimum alignment of 8 for type 'S4'}}
  28 };
  29 struct S5 : S1 {
  30   alignas(2) S1 s1; // expected-error {{requested alignment is less than minimum alignment of 8 for type 'S1'}}
  31 };
  32 struct S6 {
  33   S1 s1;
  34 };
  35 struct S7 : S1 {
  36 };
  37 struct alignas(2) alignas(8) alignas(1) S8 : S1 {
  38 };
  39
  40 S1 s1 alignas(4); // expected-error {{requested alignment is less than minimum alignment of 8 for type 'S1'}}
  41 S6 s6 alignas(4); // expected-error {{requested alignment is less than minimum alignment of 8 for type 'S6'}}
  42 S7 s7 alignas(4); // expected-error {{requested alignment is less than minimum alignment of 8 for type 'S7'}}
  43
  44 template<int N, int M, typename T>
  45 struct alignas(N) X { // expected-error 3{{requested alignment is less than minimum}}
  46   alignas(M) T t; // expected-error 3{{requested alignment is less than minimum}}
  47 };
  48
  49 template struct X<1, 1, char>;
  50 template struct X<4, 1, char>;
  51 template struct X<1, 2, char>; // expected-note {{instantiation}}
  52 template struct X<1, 1, short>; // expected-note {{instantiation}}
  53 template struct X<2, 1, short>; // expected-note {{instantiation}}
  54 template struct X<2, 2, short>;
  55 template struct X<16, 8, S1>;
  56 template struct X<4, 4, S1>; // expected-note {{instantiation}}
  57
  58 template<int N, typename T>
  59 void f() {
  60   alignas(N) T v; // expected-error {{requested alignment is less than minimum}}
  61 };
  62 template void f<1, char>();
  63 template void f<2, char>();
  64 template void f<1, short>(); // expected-note {{instantiation}}
  65 template void f<2, short>();