clang/test/SemaCXX/bitfield-layout.cpp

   1 // RUN: %clang_cc1 %s -fsyntax-only -verify -triple=x86_64-apple-darwin10
   2
   3 #define CHECK_SIZE(name, size) extern int name##1[sizeof(name) == size ? 1 : -1];
   4 #define CHECK_ALIGN(name, size) extern int name##2[__alignof(name) == size ? 1 : -1];
   5
   6 // Simple tests.
   7 struct Test1 {
   8   char c : 9; // expected-warning {{width of bit-field 'c' (9 bits) exceeds the width of its type; value will be truncated to 8 bits}}
   9 };
  10 CHECK_SIZE(Test1, 2);
  11 CHECK_ALIGN(Test1, 1);
  12
  13 struct Test1a {
  14   char : 9; // no warning (there's no value to truncate here)
  15 };
  16 CHECK_SIZE(Test1a, 2);
  17 CHECK_ALIGN(Test1a, 1);
  18
  19 struct Test2 {
  20   char c : 16; // expected-warning {{width of bit-field 'c' (16 bits) exceeds the width of its type; value will be truncated to 8 bits}}
  21 };
  22 CHECK_SIZE(Test2, 2);
  23 CHECK_ALIGN(Test2, 2);
  24
  25 struct Test3 {
  26   char c : 32; // expected-warning {{width of bit-field 'c' (32 bits) exceeds the width of its type; value will be truncated to 8 bits}}
  27 };
  28 CHECK_SIZE(Test3, 4);
  29 CHECK_ALIGN(Test3, 4);
  30
  31 struct Test4 {
  32   char c : 64; // expected-warning {{width of bit-field 'c' (64 bits) exceeds the width of its type; value will be truncated to 8 bits}}
  33 };
  34 CHECK_SIZE(Test4, 8);
  35 CHECK_ALIGN(Test4, 8);
  36
  37 struct Test5 {
  38   char c : 0x100000001; // expected-warning {{width of bit-field 'c' (4294967297 bits) exceeds the width of its type; value will be truncated to 8 bits}}
  39 };
  40 // Size and align don't really matter here, just make sure we don't crash.
  41 CHECK_SIZE(Test5, 1);
  42 CHECK_ALIGN(Test5, 1);
  43
  44 struct Test6 {
  45   char c : (unsigned __int128)0xffffffffffffffff + 2; // expected-error {{bit-field 'c' is too wide (18446744073709551617 bits)}}
  46 };
  47 // Size and align don't really matter here, just make sure we don't crash.
  48 CHECK_SIZE(Test6, 1);
  49 CHECK_ALIGN(Test6, 1);