Extract common macros and start a base library

src/base/macros.h

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_BASE_MACROS_H_
+#define V8_BASE_MACROS_H_
+
+#include "../../include/v8stdint.h"

[Sven Panne, 2014/04/23 11:38:35]

Just a note: I think we have to reconsider our include paths a bit when this is
a real library. Relative paths leaving the library won't work then...

[jochen (gone - plz use gerrit), 2014/04/23 11:50:15]

Yes

+
+
+// The expression OFFSET_OF(type, field) computes the byte-offset
+// of the specified field relative to the containing type. This
+// corresponds to 'offsetof' (in stddef.h), except that it doesn't
+// use 0 or NULL, which causes a problem with the compiler warnings
+// we have enabled (which is also why 'offsetof' doesn't seem to work).
+// Here we simply use the non-zero value 4, which seems to work.

[Nico, 2015/06/16 21:02:46]

Is this really still needed? Other places use offsetof() fine, and this comment
has been in globals.h (where you got it from) since "initial import"...

[Sven Panne, 2015/06/17 07:42:13]

Alas, yes. :-/ I made a mechanical CL
(https://codereview.chromium.org/1173343006/) which replaces OFFSET_OF with
offsetof where possible, but the rest needs more work. As it is, things are a
bit adventurous, exploring interesting corner cases of the C++ spec... :-P

+#define OFFSET_OF(type, field)                                          \
+  (reinterpret_cast<intptr_t>(&(reinterpret_cast<type*>(4)->field)) - 4)
+
+
+// The expression ARRAY_SIZE(a) is a compile-time constant of type
+// size_t which represents the number of elements of the given
+// array. You should only use ARRAY_SIZE on statically allocated
+// arrays.
+#define ARRAY_SIZE(a)                                   \
+  ((sizeof(a) / sizeof(*(a))) /                         \
+  static_cast<size_t>(!(sizeof(a) % sizeof(*(a)))))

[Sven Panne, 2014/04/23 11:38:35]

This has been here before, but anyway: The divisor seems to be some kind of
safeguard, but when exactly should it trigger? Either add an example or remove
it.

[jochen (gone - plz use gerrit), 2014/04/23 11:50:15]

See
https://code.google.com/p/chromium/codesearch#chromium/src/base/macros.h&l=107

+
+
+// A macro to disallow the evil copy constructor and operator= functions
+// This should be used in the private: declarations for a class
+#define DISALLOW_COPY_AND_ASSIGN(TypeName)  \
+  TypeName(const TypeName&) V8_DELETE;      \
+  void operator=(const TypeName&) V8_DELETE
+
+
+// A macro to disallow all the implicit constructors, namely the
+// default constructor, copy constructor and operator= functions.
+//
+// This should be used in the private: declarations for a class
+// that wants to prevent anyone from instantiating it. This is
+// especially useful for classes containing only static methods.
+#define DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName)  \
+  TypeName() V8_DELETE;                           \
+  DISALLOW_COPY_AND_ASSIGN(TypeName)
+
+
+// Newly written code should use V8_INLINE and V8_NOINLINE directly.
+#define INLINE(declarator)    V8_INLINE declarator
+#define NO_INLINE(declarator) V8_NOINLINE declarator
+
+
+// Newly written code should use V8_WARN_UNUSED_RESULT.
+#define MUST_USE_RESULT V8_WARN_UNUSED_RESULT
+
+
+// Define DISABLE_ASAN macros.
+#if defined(__has_feature)
+#if __has_feature(address_sanitizer)
+#define DISABLE_ASAN __attribute__((no_sanitize_address))
+#endif
+#endif
+
+
+#ifndef DISABLE_ASAN
+#define DISABLE_ASAN
+#endif
+
+
+#if V8_CC_GNU
+#define V8_IMMEDIATE_CRASH() __builtin_trap()
+#else
+#define V8_IMMEDIATE_CRASH() ((void(*)())0)()
+#endif
+
+#endif   // V8_BASE_MACROS_H_