clang/test/CodeGen/weak_constant.c

   1 // RUN: %clang_cc1 -w -emit-llvm %s -O1 -o - | FileCheck %s
   2 // This used to "check for bug compatibility with gcc".
   3 // Now it checks that that the "weak" declaration makes the value
   4 // fully interposable whereas a "selectany" one is handled as constant
   5 // and propagated.
   6
   7 // CHECK: @x = weak {{.*}}constant i32 123
   8 const int x __attribute((weak)) = 123;
   9
  10 // CHECK: @y = weak_odr {{.*}}constant i32 234
  11 const int y __attribute((selectany)) = 234;
  12
  13 int* f(void) {
  14   return &x;
  15 }
  16
  17 int g(void) {
  18   // CHECK: load i32, ptr @x
  19   // CHECK-NOT: ret i32 123
  20   return *f();
  21 }
  22
  23 int *k(void) {
  24   return &y;
  25 }
  26
  27 int l(void) {
  28   // CHECK-NOT: load i32, ptr @y
  29   // CHECK: ret i32 234
  30   return *k();
  31 }