clang/test/CodeGenCXX/std-byte.cpp

   1 // RUN: %clang_cc1 -std=c++1z -Werror -triple i386-unknown-unknown -emit-llvm -O1 -disable-llvm-passes -o - %s | FileCheck %s
   2
   3 // std::byte should be considered equivalent to char for aliasing.
   4
   5 namespace std {
   6 enum byte : unsigned char {};
   7 }
   8
   9 // CHECK-LABEL: define{{.*}} void @test0(
  10 extern "C" void test0(std::byte *sb, int *i) {
  11   // CHECK: store i8 0, ptr %{{.*}} !tbaa [[TAG_CHAR:!.*]]
  12   *sb = std::byte{0};
  13
  14   // CHECK: store i32 1, ptr %{{.*}} !tbaa [[TAG_INT:!.*]]
  15   *i = 1;
  16 }
  17
  18 enum byte : unsigned char {};
  19 namespace my {
  20 enum byte : unsigned char {};
  21 namespace std {
  22 enum byte : unsigned char {};
  23 } // namespace std
  24 } // namespace my
  25
  26 // Make sure we don't get confused with other enums named 'byte'.
  27
  28 // CHECK-LABEL: define{{.*}} void @test1(
  29 extern "C" void test1(::byte *b, ::my::byte *mb, ::my::std::byte *msb) {
  30   *b = ::byte{0};
  31   *mb = ::my::byte{0};
  32   *msb = ::my::std::byte{0};
  33   // CHECK-NOT: store i8 0, ptr %{{.*}} !tbaa [[TAG_CHAR]]
  34 }
  35
  36 // CHECK:  !"any pointer", [[TYPE_CHAR:!.*]],
  37 // CHECK: [[TYPE_CHAR]] = !{!"omnipotent char", [[TAG_CXX_TBAA:!.*]],
  38 // CHECK: [[TAG_CXX_TBAA]] = !{!"Simple C++ TBAA"}
  39 // CHECK: [[TAG_CHAR]] = !{[[TYPE_CHAR:!.*]], [[TYPE_CHAR]], i64 0}
  40 // CHECK: [[TAG_INT]] = !{[[TYPE_INT:!.*]], [[TYPE_INT]], i64 0}
  41 // CHECK: [[TYPE_INT]] = !{!"int", [[TYPE_CHAR]]