mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-08 20:47:44 +00:00
262 lines
11 KiB
C++
262 lines
11 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
|
|
* vim: set ts=8 sw=4 et tw=99 ft=cpp:
|
|
*
|
|
* ***** BEGIN LICENSE BLOCK *****
|
|
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
|
|
*
|
|
* The contents of this file are subject to the Mozilla Public License Version
|
|
* 1.1 (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.mozilla.org/MPL/
|
|
*
|
|
* Software distributed under the License is distributed on an "AS IS" basis,
|
|
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
|
|
* for the specific language governing rights and limitations under the
|
|
* License.
|
|
*
|
|
* The Original Code is Mozilla Code.
|
|
*
|
|
* The Initial Developer of the Original Code is
|
|
* The Mozilla Foundation
|
|
* Portions created by the Initial Developer are Copyright (C) 2011
|
|
* the Initial Developer. All Rights Reserved.
|
|
*
|
|
* Contributor(s):
|
|
* Jeff Walden <jwalden+code@mit.edu>
|
|
*
|
|
* Alternatively, the contents of this file may be used under the terms of
|
|
* either the GNU General Public License Version 2 or later (the "GPL"), or
|
|
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
|
|
* in which case the provisions of the GPL or the LGPL are applicable instead
|
|
* of those above. If you wish to allow use of your version of this file only
|
|
* under the terms of either the GPL or the LGPL, and not to allow others to
|
|
* use your version of this file under the terms of the MPL, indicate your
|
|
* decision by deleting the provisions above and replace them with the notice
|
|
* and other provisions required by the GPL or the LGPL. If you do not delete
|
|
* the provisions above, a recipient may use your version of this file under
|
|
* the terms of any one of the MPL, the GPL or the LGPL.
|
|
*
|
|
* ***** END LICENSE BLOCK ***** */
|
|
|
|
/* Implementations of runtime and static assertion macros for C and C++. */
|
|
|
|
#ifndef mozilla_Assertions_h_
|
|
#define mozilla_Assertions_h_
|
|
|
|
#include "mozilla/Types.h"
|
|
|
|
/*
|
|
* MOZ_STATIC_ASSERT may be used to assert a condition *at compile time*. This
|
|
* can be useful when you make certain assumptions about what must hold for
|
|
* optimal, or even correct, behavior. For example, you might assert that the
|
|
* size of a struct is a multiple of the target architecture's word size:
|
|
*
|
|
* struct S { ... };
|
|
* MOZ_STATIC_ASSERT(sizeof(S) % sizeof(size_t) == 0,
|
|
* "S should be a multiple of word size for efficiency");
|
|
*
|
|
* This macro can be used in any location where both an extern declaration and a
|
|
* typedef could be used.
|
|
*
|
|
* Be aware of the gcc 4.2 concerns noted further down when writing patches that
|
|
* use this macro, particularly if a patch only bounces on OS X.
|
|
*/
|
|
#ifdef __cplusplus
|
|
# if defined(__clang__)
|
|
# ifndef __has_extension
|
|
# define __has_extension __has_feature /* compatibility, for older versions of clang */
|
|
# endif
|
|
# if __has_extension(cxx_static_assert)
|
|
# define MOZ_STATIC_ASSERT(cond, reason) static_assert((cond), reason)
|
|
# endif
|
|
# elif defined(__GNUC__)
|
|
# if (defined(__GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L) && \
|
|
(__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
|
|
# define MOZ_STATIC_ASSERT(cond, reason) static_assert((cond), reason)
|
|
# endif
|
|
# elif defined(_MSC_VER)
|
|
# if _MSC_VER >= 1600 /* MSVC 10 */
|
|
# define MOZ_STATIC_ASSERT(cond, reason) static_assert((cond), reason)
|
|
# endif
|
|
# elif defined(__HP_aCC)
|
|
# if __HP_aCC >= 62500 && defined(_HP_CXX0x_SOURCE)
|
|
# define MOZ_STATIC_ASSERT(cond, reason) static_assert((cond), reason)
|
|
# endif
|
|
# endif
|
|
#endif
|
|
#ifndef MOZ_STATIC_ASSERT
|
|
# define MOZ_STATIC_ASSERT_GLUE1(x, y) x##y
|
|
# define MOZ_STATIC_ASSERT_GLUE(x, y) MOZ_STATIC_ASSERT_GLUE1(x, y)
|
|
# if defined(__SUNPRO_CC)
|
|
/*
|
|
* The Sun Studio C++ compiler is buggy when declaring, inside a function,
|
|
* another extern'd function with an array argument whose length contains a
|
|
* sizeof, triggering the error message "sizeof expression not accepted as
|
|
* size of array parameter". This bug (6688515, not public yet) would hit
|
|
* defining moz_static_assert as a function, so we always define an extern
|
|
* array for Sun Studio.
|
|
*
|
|
* We include the line number in the symbol name in a best-effort attempt
|
|
* to avoid conflicts (see below).
|
|
*/
|
|
# define MOZ_STATIC_ASSERT(cond, reason) \
|
|
extern char MOZ_STATIC_ASSERT_GLUE(moz_static_assert, __LINE__)[(cond) ? 1 : -1]
|
|
# elif defined(__COUNTER__)
|
|
/*
|
|
* If there was no preferred alternative, use a compiler-agnostic version.
|
|
*
|
|
* Note that the non-__COUNTER__ version has a bug in C++: it can't be used
|
|
* in both |extern "C"| and normal C++ in the same translation unit. (Alas
|
|
* |extern "C"| isn't allowed in a function.) The only affected compiler
|
|
* we really care about is gcc 4.2. For that compiler and others like it,
|
|
* we include the line number in the function name to do the best we can to
|
|
* avoid conflicts. These should be rare: a conflict would require use of
|
|
* MOZ_STATIC_ASSERT on the same line in separate files in the same
|
|
* translation unit, *and* the uses would have to be in code with
|
|
* different linkage, *and* the first observed use must be in C++-linkage
|
|
* code.
|
|
*/
|
|
# define MOZ_STATIC_ASSERT(cond, reason) \
|
|
typedef int MOZ_STATIC_ASSERT_GLUE(moz_static_assert, __COUNTER__)[(cond) ? 1 : -1]
|
|
# else
|
|
# define MOZ_STATIC_ASSERT(cond, reason) \
|
|
extern void MOZ_STATIC_ASSERT_GLUE(moz_static_assert, __LINE__)(int arg[(cond) ? 1 : -1])
|
|
# endif
|
|
#endif
|
|
|
|
#define MOZ_STATIC_ASSERT_IF(cond, expr, reason) MOZ_STATIC_ASSERT(!(cond) || (expr), reason)
|
|
|
|
/*
|
|
* XXX: we're cheating here in order to avoid creating object files
|
|
* for mfbt /just/ to provide a function like FatalError() to be used
|
|
* by MOZ_ASSERT(). (It'll happen eventually, but for just ASSERT()
|
|
* it isn't worth the pain.) JS_Assert(), although unfortunately
|
|
* named, is part of SpiderMonkey's stable, external API, so this
|
|
* isn't quite as bad as it seems.
|
|
*
|
|
* Once mfbt needs object files, this unholy union with JS_Assert()
|
|
* will be broken.
|
|
*
|
|
* JS_Assert is present even in release builds, for the benefit of applications
|
|
* that build DEBUG and link against a non-DEBUG SpiderMonkey library.
|
|
*/
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
extern MFBT_API(void)
|
|
JS_Assert(const char* s, const char* file, int ln);
|
|
|
|
#ifdef __cplusplus
|
|
} /* extern "C" */
|
|
#endif
|
|
|
|
/*
|
|
* MOZ_ASSERT(expr [, explanation-string]) asserts that |expr| must be truthy in
|
|
* debug builds. If it is, execution continues. Otherwise, an error message
|
|
* including the expression and the explanation-string (if provided) is printed,
|
|
* an attempt is made to invoke any existing debugger, and execution halts.
|
|
* MOZ_ASSERT is fatal: no recovery is possible. Do not assert a condition
|
|
* which can correctly be falsy.
|
|
*
|
|
* The optional explanation-string, if provided, must be a string literal
|
|
* explaining the assertion. It is intended for use with assertions whose
|
|
* correctness or rationale is non-obvious, and for assertions where the "real"
|
|
* condition being tested is best described prosaically. Don't provide an
|
|
* explanation if it's not actually helpful.
|
|
*
|
|
* // No explanation needed: pointer arguments often must not be NULL.
|
|
* MOZ_ASSERT(arg);
|
|
*
|
|
* // An explanation can be helpful to explain exactly how we know an
|
|
* // assertion is valid.
|
|
* MOZ_ASSERT(state == WAITING_FOR_RESPONSE,
|
|
* "given that <thingA> and <thingB>, we must have...");
|
|
*
|
|
* // Or it might disambiguate multiple identical (save for their location)
|
|
* // assertions of the same expression.
|
|
* MOZ_ASSERT(getSlot(PRIMITIVE_THIS_SLOT).isUndefined(),
|
|
* "we already set [[PrimitiveThis]] for this Boolean object");
|
|
* MOZ_ASSERT(getSlot(PRIMITIVE_THIS_SLOT).isUndefined(),
|
|
* "we already set [[PrimitiveThis]] for this String object");
|
|
*
|
|
* MOZ_ASSERT has no effect in non-debug builds. It is designed to catch bugs
|
|
* *only* during debugging, not "in the field".
|
|
*/
|
|
#ifdef DEBUG
|
|
/* First the single-argument form. */
|
|
# define MOZ_ASSERT_HELPER1(expr) \
|
|
((expr) ? ((void)0) : JS_Assert(#expr, __FILE__, __LINE__))
|
|
/* Now the two-argument form. */
|
|
# define MOZ_ASSERT_HELPER2(expr, explain) \
|
|
((expr) ? ((void)0) : JS_Assert(#expr " (" explain ")", __FILE__, __LINE__))
|
|
/* And now, helper macrology up the wazoo. */
|
|
/* Count the number of arguments passed to MOZ_ASSERT. */
|
|
# define MOZ_COUNT_ASSERT_ARGS(...) \
|
|
MOZ_COUNT_ASSERT_ARGS_IMPL(__VA_ARGS__, 2, 1, 0)
|
|
# define MOZ_COUNT_ASSERT_ARGS_IMPL(_1, _2, count, ...) \
|
|
count
|
|
/* Invoke the right helper. */
|
|
# define MOZ_ASSERT_VAHELP2(count, ...) MOZ_ASSERT_HELPER##count(__VA_ARGS__)
|
|
# define MOZ_ASSERT_VAHELP(count, ...) MOZ_ASSERT_VAHELP2(count, __VA_ARGS__)
|
|
/* The actual macro. */
|
|
# define MOZ_ASSERT(...) \
|
|
MOZ_ASSERT_VAHELP(MOZ_COUNT_ASSERT_ARGS(__VA_ARGS__), __VA_ARGS__)
|
|
#else
|
|
# define MOZ_ASSERT(...) ((void)0)
|
|
#endif /* DEBUG */
|
|
|
|
/*
|
|
* MOZ_ASSERT_IF(cond1, cond2) is equivalent to MOZ_ASSERT(cond2) if cond1 is
|
|
* true.
|
|
*
|
|
* MOZ_ASSERT_IF(isPrime(num), num == 2 || isOdd(num));
|
|
*
|
|
* As with MOZ_ASSERT, MOZ_ASSERT_IF has effect only in debug builds. It is
|
|
* designed to catch bugs during debugging, not "in the field".
|
|
*/
|
|
#ifdef DEBUG
|
|
# define MOZ_ASSERT_IF(cond, expr) ((cond) ? MOZ_ASSERT(expr) : ((void)0))
|
|
#else
|
|
# define MOZ_ASSERT_IF(cond, expr) ((void)0)
|
|
#endif
|
|
|
|
/*
|
|
* MOZ_NOT_REACHED(reason) indicates that the given point can't be reached
|
|
* during execution: simply reaching that point in execution is a bug. It takes
|
|
* as an argument an error message indicating the reason why that point should
|
|
* not have been reachable.
|
|
*
|
|
* // ...in a language parser...
|
|
* void handle(BooleanLiteralNode node)
|
|
* {
|
|
* if (node.isTrue())
|
|
* handleTrueLiteral();
|
|
* else if (node.isFalse())
|
|
* handleFalseLiteral();
|
|
* else
|
|
* MOZ_NOT_REACHED("boolean literal that's not true or false?");
|
|
* }
|
|
*/
|
|
#ifdef DEBUG
|
|
# define MOZ_NOT_REACHED(reason) JS_Assert(reason, __FILE__, __LINE__)
|
|
#else
|
|
# define MOZ_NOT_REACHED(reason) ((void)0)
|
|
#endif
|
|
|
|
/*
|
|
* MOZ_ALWAYS_TRUE(expr) and MOZ_ALWAYS_FALSE(expr) always evaluate the provided
|
|
* expression, in debug builds and in release builds both. Then, in debug
|
|
* builds only, the value of the expression is asserted either true or false
|
|
* using MOZ_ASSERT.
|
|
*/
|
|
#ifdef DEBUG
|
|
# define MOZ_ALWAYS_TRUE(expr) MOZ_ASSERT((expr))
|
|
# define MOZ_ALWAYS_FALSE(expr) MOZ_ASSERT(!(expr))
|
|
#else
|
|
# define MOZ_ALWAYS_TRUE(expr) ((void)(expr))
|
|
# define MOZ_ALWAYS_FALSE(expr) ((void)(expr))
|
|
#endif
|
|
|
|
#endif /* mozilla_Assertions_h_ */
|