third_party/WebKit/Source/wtf/SizeLimits.cpp

   1 /*
   2  * Copyright (C) 2010 Google Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
  15  * contributors may be used to endorse or promote products derived from
  16  * this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include "config.h"
  32
  33 #include "wtf/Assertions.h"
  34 #include "wtf/ContainerAnnotations.h"
  35 #include "wtf/OwnPtr.h"
  36 #include "wtf/PassRefPtr.h"
  37 #include "wtf/RefCounted.h"
  38 #include "wtf/RefPtr.h"
  39 #include "wtf/ThreadRestrictionVerifier.h"
  40 #include "wtf/Vector.h"
  41 #include "wtf/text/AtomicString.h"
  42 #include "wtf/text/WTFString.h"
  43
  44 namespace WTF {
  45
  46 #if ENABLE(ASSERT) || ENABLE(SECURITY_ASSERT)
  47 // The debug/assertion version may get bigger.
  48 struct SameSizeAsRefCounted {
  49     int a;
  50 #if ENABLE(SECURITY_ASSERT)
  51     bool b;
  52 #endif
  53 #if ENABLE(ASSERT)
  54     bool c;
  55     ThreadRestrictionVerifier d;
  56 #endif
  57 };
  58 #else
  59 struct SameSizeAsRefCounted {
  60     int a;
  61     // Don't add anything here because this should stay small.
  62 };
  63 #endif
  64 template<typename T, unsigned inlineCapacity = 0>
  65 struct SameSizeAsVectorWithInlineCapacity;
  66
  67 template<typename T>
  68 struct SameSizeAsVectorWithInlineCapacity<T, 0> {
  69     void* bufferPointer;
  70     unsigned capacity;
  71     unsigned size;
  72 };
  73
  74 template<typename T, unsigned inlineCapacity>
  75 struct SameSizeAsVectorWithInlineCapacity {
  76     SameSizeAsVectorWithInlineCapacity<T, 0> baseCapacity;
  77 #if !defined(ANNOTATE_CONTIGUOUS_CONTAINER)
  78     AlignedBuffer<inlineCapacity * sizeof(T), WTF_ALIGN_OF(T)> inlineBuffer;
  79 #endif
  80 };
  81
  82 static_assert(sizeof(OwnPtr<int>) == sizeof(int*), "OwnPtr should stay small");
  83 static_assert(sizeof(PassRefPtr<RefCounted<int>>) == sizeof(int*), "PassRefPtr should stay small");
  84 static_assert(sizeof(RefCounted<int>) == sizeof(SameSizeAsRefCounted), "RefCounted should stay small");
  85 static_assert(sizeof(RefPtr<RefCounted<int>>) == sizeof(int*), "RefPtr should stay small");
  86 static_assert(sizeof(String) == sizeof(int*), "String should stay small");
  87 static_assert(sizeof(AtomicString) == sizeof(String), "AtomicString should stay small");
  88 static_assert(sizeof(Vector<int>) == sizeof(SameSizeAsVectorWithInlineCapacity<int>), "Vector should stay small");
  89 static_assert(sizeof(Vector<int, 1>) == sizeof(SameSizeAsVectorWithInlineCapacity<int, 1>), "Vector should stay small");
  90 static_assert(sizeof(Vector<int, 2>) == sizeof(SameSizeAsVectorWithInlineCapacity<int, 2>), "Vector should stay small");
  91 static_assert(sizeof(Vector<int, 3>) == sizeof(SameSizeAsVectorWithInlineCapacity<int, 3>), "Vector should stay small");
  92 }