| // checking for POD zero initialization |
| |
| /*************************************************************************** |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed |
| * with this work for additional information regarding copyright |
| * ownership. The ASF licenses this file to you under the Apache |
| * License, Version 2.0 (the License); you may not use this file |
| * except in compliance with the License. You may obtain a copy of |
| * the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or |
| * implied. See the License for the specific language governing |
| * permissions and limitations under the License. |
| * |
| * Copyright 1999-2007 Rogue Wave Software, Inc. |
| * |
| **************************************************************************/ |
| |
| #include "config.h" |
| |
| #ifndef _RWSTD_NO_NEW |
| # include <new> |
| #elif !defined (_RWSTD_NO_NEW_H) |
| # include <new.h> |
| #else |
| |
| # ifndef _RWSTD_SIZE_T |
| # define _RWSTD_SIZE_T unsigned long |
| # endif |
| |
| inline void* operator new (_RWSTD_SIZE_T, void *p) |
| { |
| return p; |
| } |
| |
| #endif |
| |
| |
| struct A { |
| char m1; |
| short m2; |
| int m3; |
| float m4; |
| double m5; |
| void* m6; |
| char m7 [7]; |
| void (A::*m8)(); |
| }; |
| |
| |
| template <class T> |
| struct S |
| { |
| T t_; |
| |
| S (T t = T ()): t_ (t) { } // must zero initialize `t' if POD |
| }; |
| |
| |
| template <class T> |
| struct X |
| { |
| S<A> s; |
| |
| X (): s () { } // must zero initialize `s' if POD |
| }; |
| |
| |
| int is_zero (const void *pv, unsigned n) |
| { |
| const char *pc = (const char*)pv; |
| |
| for (unsigned i = 0; i != n; ++i) |
| if (pc [i]) |
| return 0; |
| |
| return -1; |
| } |
| |
| int is_A_zero (const A &a) |
| { |
| return is_zero (&a.m1, sizeof a.m1) |
| && is_zero (&a.m2, sizeof a.m2) |
| && is_zero (&a.m3, sizeof a.m3) |
| && is_zero (&a.m4, sizeof a.m4) |
| && is_zero (&a.m5, sizeof a.m5) |
| && is_zero (&a.m6, sizeof a.m6) |
| && is_zero (&a.m7, sizeof a.m7) |
| && is_zero (&a.m8, sizeof a.m8); |
| } |
| |
| int is_SA_zero (const S<A> &s) |
| { |
| return is_A_zero (s.t_); |
| } |
| |
| template <class T> |
| int is_X_zero (const X<T> &x) |
| { |
| return is_SA_zero (x.s); |
| } |
| |
| void setmem (void *pv, unsigned n, char b) |
| { |
| char buf [256]; |
| |
| char *pc = (char*)pv; |
| |
| // set memory to the value of `b' |
| for (unsigned i = 0; i != n; ++i) |
| pc [i] = b; |
| |
| // dirty up the stack in the process |
| for (unsigned j = 0; j != sizeof buf; ++j) |
| buf [j] = b; |
| } |
| |
| |
| int main () |
| { |
| union { |
| char buf [256]; |
| void *pad; |
| } u; |
| |
| int result = 0; |
| |
| setmem (&u, sizeof u, 'x'); |
| |
| // check that a fundamental type is zeroed out on initialization |
| int i = int (); |
| |
| if (i != 0) |
| result |= 1; |
| |
| // check that a POD object is zeroed out on initialization |
| A a = A (); |
| |
| if (!is_A_zero (a)) |
| result |= 2; |
| |
| // check that a POD object is zeroed out on initialization with operator new |
| A *pa = new (&u) A (); |
| |
| if (!is_A_zero (*pa)) |
| result |= 4; |
| |
| setmem (&u, sizeof u, 'x'); |
| |
| S<A> *ps = new (&u) S<A>(); |
| |
| if (!is_SA_zero (*ps)) |
| result |= 8; |
| |
| setmem (&u, sizeof u, 'x'); |
| |
| X<int> *px = new (&u) X<int>(); |
| |
| if (!is_X_zero (*px)) |
| result |= 16; |
| |
| setmem (&u, sizeof u, 'x'); |
| |
| *px = X<int>(); |
| |
| if (!is_X_zero (*px)) |
| result |= 32; |
| |
| return result; |
| } |