clang/test/CodeGen/catch-nullptr-and-nonzero-offset-in-offsetof-idiom.c

   1 // NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
   2 // RUN: %clang_cc1 -x c   -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s
   3 // RUN: %clang_cc1 -x c   -fsanitize=pointer-overflow -fno-sanitize-recover=pointer-overflow -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s
   4
   5 // RUN: %clang_cc1 -x c++ -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s
   6 // RUN: %clang_cc1 -x c++ -fsanitize=pointer-overflow -fno-sanitize-recover=pointer-overflow -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s
   7
   8 #include <stdint.h>
   9
  10 #ifdef __cplusplus
  11 extern "C" {
  12 #endif
  13
  14 struct S {
  15   int x, y;
  16 };
  17
  18 // CHECK-LABEL: @get_offset_of_y_naively(
  19 // CHECK-NEXT:  entry:
  20 // CHECK-NEXT:    ret i64 ptrtoint (ptr getelementptr inbounds nuw ([[STRUCT_S:%.*]], ptr null, i32 0, i32 1) to i64)
  21 //
  22 uintptr_t get_offset_of_y_naively(void) {
  23   return ((uintptr_t)(&(((struct S *)0)->y)));
  24 }
  25
  26 // CHECK-LABEL: @get_offset_of_y_via_builtin(
  27 // CHECK-NEXT:  entry:
  28 // CHECK-NEXT:    ret i64 4
  29 //
  30 uintptr_t get_offset_of_y_via_builtin(void) {
  31   return __builtin_offsetof(struct S, y);
  32 }
  33
  34 #ifdef __cplusplus
  35 }
  36 #endif