clang/test/CodeGenCXX/catch-nullptr-and-nonzero-offset-in-offsetof-idiom.cpp

// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
// RUN: %clang_cc1 -x c++ -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s
// RUN: %clang_cc1 -x c++ -fsanitize=pointer-overflow -fno-sanitize-recover=pointer-overflow -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s

#include <stdint.h>

struct S {
  int x, y;
};

// CHECK-LABEL: @_Z23get_offset_of_y_naivelyv(
// CHECK-NEXT:  entry:
// CHECK-NEXT:    ret i64 ptrtoint (ptr getelementptr ([[STRUCT_S:%.*]], ptr null, i32 0, i32 1) to i64)
//
uintptr_t get_offset_of_y_naively() {
  return ((uintptr_t)(&(((S *)nullptr)->y)));
}

struct Empty {};

struct T {
  int a;
  S s;
  [[no_unique_address]] Empty e1;
  int b;
  [[no_unique_address]] Empty e2;
};

// CHECK-LABEL: @_Z30get_offset_of_y_naively_nestedv(
// CHECK-NEXT:  entry:
// CHECK-NEXT:    ret i64 ptrtoint (ptr getelementptr ([[STRUCT_S:%.*]], ptr getelementptr ([[STRUCT_T:%.*]], ptr null, i32 0, i32 1), i32 0, i32 1) to i64)
//
uintptr_t get_offset_of_y_naively_nested() {
  return ((uintptr_t)(&(((T *)nullptr)->s.y)));
}

// CHECK-LABEL: @_Z42get_offset_of_y_naively_nested_with_parensv(
// CHECK-NEXT:  entry:
// CHECK-NEXT:    ret i64 ptrtoint (ptr getelementptr ([[STRUCT_S:%.*]], ptr getelementptr ([[STRUCT_T:%.*]], ptr null, i32 0, i32 1), i32 0, i32 1) to i64)
//
uintptr_t get_offset_of_y_naively_nested_with_parens() {
  return ((uintptr_t)(&((((T *)nullptr)->s).y)));
}

// CHECK-LABEL: @_Z26get_offset_of_zero_storagev(
// CHECK-NEXT:  entry:
// CHECK-NEXT:    ret i64 ptrtoint (ptr getelementptr (i8, ptr null, i64 16) to i64)
//
uintptr_t get_offset_of_zero_storage() {
  return ((uintptr_t)(&(((T *)nullptr)->e2)));
}

namespace std { typedef decltype(__nullptr) nullptr_t; }
// CHECK-LABEL: @_Z29get_offset_of_y_integral_zerov(
// CHECK-NEXT:  entry:
// CHECK-NEXT:    ret i64 ptrtoint (ptr getelementptr ([[STRUCT_S:%.*]], ptr null, i32 0, i32 1) to i64)
//
uintptr_t get_offset_of_y_integral_zero() {
  return ((uintptr_t)(&(((S *)0)->y)));
}

// CHECK-LABEL: @_Z37get_offset_of_y_integral_zero_voidptrv(
// CHECK-NEXT:  entry:
// CHECK-NEXT:    ret i64 ptrtoint (ptr getelementptr ([[STRUCT_S:%.*]], ptr null, i32 0, i32 1) to i64)
//
uintptr_t get_offset_of_y_integral_zero_voidptr() {
  return ((uintptr_t)(&(((S *)(void*)0)->y)));
}

// CHECK-LABEL: @_Z25get_offset_of_y_nullptr_tv(
// CHECK-NEXT:  entry:
// CHECK-NEXT:    ret i64 ptrtoint (ptr getelementptr ([[STRUCT_S:%.*]], ptr null, i32 0, i32 1) to i64)
//
uintptr_t get_offset_of_y_nullptr_t() {
  return ((uintptr_t)(&(((S *)std::nullptr_t{})->y)));
}

// CHECK-LABEL: @_Z32get_offset_of_y_nullptr_constantv(
// CHECK-NEXT:  entry:
// CHECK-NEXT:    [[NULL:%.*]] = alloca ptr, align 8
// CHECK-NEXT:    store ptr null, ptr [[NULL]], align 8
// CHECK-NEXT:    ret i64 ptrtoint (ptr getelementptr inbounds nuw ([[STRUCT_S:%.*]], ptr null, i32 0, i32 1) to i64)
//
uintptr_t get_offset_of_y_nullptr_constant() {
  constexpr void *null = nullptr;
  return ((uintptr_t)(&(((S *)null)->y)));
}

// CHECK-LABEL: @_Z27get_offset_of_y_via_builtinv(
// CHECK-NEXT:  entry:
// CHECK-NEXT:    ret i64 4
//
uintptr_t get_offset_of_y_via_builtin() {
  return __builtin_offsetof(S, y);
}