llvm-project/llvm/test/CFrontend/2007-06-15-AnnotateAttribute.c

// RUN: %llvmgcc -c -emit-llvm %s -o - | llvm-dis | grep llvm.global.annotations
// RUN: %llvmgcc -c -emit-llvm %s -o - | llvm-dis | grep llvm.var.annotation | count 3 

#include <stdio.h>

/* Global variable with attribute */
int X __attribute__((annotate("GlobalValAnnotation")));

/* Function with attribute */
int foo(int y) __attribute__((annotate("GlobalValAnnotation"))) 
               __attribute__((noinline));

int foo(int y __attribute__((annotate("LocalValAnnotation")))) {
  int x __attribute__((annotate("LocalValAnnotation")));
  x = 34;
  return y + x;
} 

int main() {
  static int a __attribute__((annotate("GlobalValAnnotation")));
  a = foo(2);
  printf("hello world%d\n", a);
  return 0;
}