text: // RUN: %clang_profgen -DCHECK_SYMBOLS -O3 -o %t.symbols %s
  // RUN: llvm-nm %t.symbols | FileCheck %s --check-prefix=CHECK-SYMBOLS
  // RUN: %clang_profgen -O3 -o %t %s
  // RUN: %run %t %t.profraw
  // RUN: llvm-profdata merge -o %t.profdata %t.profraw
  // RUN: %clang_profuse=%t.profdata -o - -S -emit-llvm %s | FileCheck %s
  
  // This usage of llvm-nm assumes executables have symbol tables. They do not in
  // an MSVC environment, so we can't make this test portable.
  // UNSUPPORTED: msvc
  
  #include <stdint.h>
  #include <stdlib.h>
  
  #ifndef CHECK_SYMBOLS
  #include <stdio.h>
  #endif
  
  int __llvm_profile_runtime = 0;
  uint64_t __llvm_profile_get_size_for_buffer(void);
  int __llvm_profile_write_buffer(char *);
  void __llvm_profile_merge_from_buffer(const char *, uint64_t Size);
  
  int write_buffer(uint64_t, const char *);
  int main(int argc, const char *argv[]) {
    // CHECK-LABEL: define {{.*}} @main(
    // CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{.*}}, !prof ![[PD1:[0-9]+]]
    if (argc < 2)
      return 1;
  
    const uint64_t MaxSize = 10000;
    static char Buffer[MaxSize];
  
    uint64_t Size = __llvm_profile_get_size_for_buffer();
    if (Size > MaxSize)
      return 1;
    int Write = __llvm_profile_write_buffer(Buffer);
    if (Write)
      return Write;
  
  #ifdef CHECK_SYMBOLS
    // Don't write it out.  Since we're checking the symbols, we don't have libc
    // available.
    // Call merge function to make sure it does not bring in libc deps:
    __llvm_profile_merge_from_buffer(Buffer, Size);
    return 0;
  #else
    // Actually write it out so we can FileCheck the output.
    FILE *File = fopen(argv[1], "w");
    if (!File)
      return 1;
    if (fwrite(Buffer, 1, Size, File) != Size)
      return 1;
    return fclose(File);
  #endif
  }
  // CHECK: ![[PD1]] = !{!"branch_weights", i32 1, i32 2}
  
  // CHECK-SYMBOLS-NOT: {{ }}___cxx_global_var_init
  // CHECK-SYMBOLS-NOT: {{ }}___llvm_profile_register_write_file_atexit
  // CHECK-SYMBOLS-NOT: {{ }}___llvm_profile_set_filename
  // CHECK-SYMBOLS-NOT: {{ }}___llvm_profile_write_file
  // CHECK-SYMBOLS-NOT: {{ }}_fdopen
  // CHECK-SYMBOLS-NOT: {{ }}_fopen
  // CHECK-SYMBOLS-NOT: {{ }}_fwrite
  // CHECK-SYMBOLS-NOT: {{ }}_getenv
  // CHECK-SYMBOLS-NOT: {{ }}getenv
  // CHECK-SYMBOLS-NOT: {{ }}_malloc
  // CHECK-SYMBOLS-NOT: {{ }}malloc
  // CHECK-SYMBOLS-NOT: {{ }}_calloc
  // CHECK-SYMBOLS-NOT: {{ }}calloc
  // CHECK-SYMBOLS-NOT: {{ }}_free
  // CHECK-SYMBOLS-NOT: {{ }}free
  // CHECK-SYMBOLS-NOT: {{ }}_open
  // CHECK-SYMBOLS-NOT: {{ }}_getpagesize
  