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ruby--ruby/include/ruby/assert.h
Gannon McGibbon 9e0075a3d9 Replace "iff" with "if and only if"
iff means if and only if, but readers without that knowledge might
assume this to be a spelling mistake. To me, this seems like
exclusionary language that is unnecessary. Simply using "if and only if"
instead should suffice.
2021-01-19 12:06:45 -08:00

234 lines
7.5 KiB
C++

#ifndef RUBY_ASSERT_H /*-*-C++-*-vi:se ft=cpp:*/
#define RUBY_ASSERT_H
/**
* @file
* @author Ruby developers <ruby-core@ruby-lang.org>
* @date Wed May 18 00:21:44 JST 1994
* @copyright This file is a part of the programming language Ruby.
* Permission is hereby granted, to either redistribute and/or
* modify this file, provided that the conditions mentioned in the
* file COPYING are met. Consult the file for details.
* @warning Symbols prefixed with either `RBIMPL` or `rbimpl` are
* implementation details. Don't take them as canon. They could
* rapidly appear then vanish. The name (path) of this header file
* is also an implementation detail. Do not expect it to persist
* at the place it is now. Developers are free to move it anywhere
* anytime at will.
* @note To ruby-core: remember that this header can be possibly
* recursively included from extension libraries written in C++.
* Do not expect for instance `__VA_ARGS__` is always available.
* We assume C99 for ruby itself but we don't assume languages of
* extension libraries. They could be written in C++98.
*/
#include "ruby/internal/assume.h"
#include "ruby/internal/attr/cold.h"
#include "ruby/internal/attr/noreturn.h"
#include "ruby/internal/cast.h"
#include "ruby/internal/dllexport.h"
#include "ruby/backward/2/assume.h"
/* RUBY_NDEBUG is very simple: after everything described below are done,
* define it with either NDEBUG is undefined (=0) or defined (=1). It is truly
* subordinate.
*
* RUBY_DEBUG versus NDEBUG is complicated. Assertions shall be:
*
* | -UNDEBUG | -DNDEBUG
* ---------------+----------+---------
* -URUBY_DEBUG | (*1) | disabled
* -DRUBY_DEBUG=0 | disabled | disabled
* -DRUBY_DEBUG=1 | enabled | (*2)
* -DRUBY_DEBUG | enabled | (*2)
*
* where:
*
* - (*1): Assertions shall be silently disabled, no warnings, in favour of
* commit 21991e6ca59274e41a472b5256bd3245f6596c90.
*
* - (*2): Compile-time warnings shall be issued.
*/
/** @cond INTERNAL_MACRO */
/*
* Pro tip: `!!RUBY_DEBUG-1` expands to...
*
* - `!!(-1)` (== `!0` == `1`) when RUBY_DEBUG is defined to be empty,
* - `(!!0)-1` (== `0-1` == `-1`) when RUBY_DEBUG is defined as 0, and
* - `(!!n)-1` (== `1-1` == `0`) when RUBY_DEBUG is defined as something else.
*/
#if ! defined(RUBY_DEBUG)
# define RBIMPL_RUBY_DEBUG 0
#elif !!RUBY_DEBUG-1 < 0
# define RBIMPL_RUBY_DEBUG 0
#else
# define RBIMPL_RUBY_DEBUG 1
#endif
/*
* ISO/IEC 9899 (all past versions) says that "If NDEBUG is defined as a macro
* name at the point in the source file where <assert.h> is included, ..."
* which means we must not take its defined value into account.
*/
#if defined(NDEBUG)
# define RBIMPL_NDEBUG 1
#else
# define RBIMPL_NDEBUG 0
#endif
/** @endcond */
/* Here we go... */
#undef RUBY_DEBUG
#undef RUBY_NDEBUG
#undef NDEBUG
#if defined(__DOXYGEN__)
# /** Define this macro when you want assertions. */
# define RUBY_DEBUG 0
# /** Define this macro when you don't want assertions. */
# define NDEBUG
# /** This macro is basically the same as #NDEBUG */
# define RUBY_NDEBUG 1
#elif (RBIMPL_NDEBUG == 1) && (RBIMPL_RUBY_DEBUG == 0)
# /* Assertions disabled as per request, no conflicts. */
# define RUBY_DEBUG 0
# define RUBY_NDEBUG 1
# define NDEBUG
#elif (RBIMPL_NDEBUG == 0) && (RBIMPL_RUBY_DEBUG == 1)
# /* Assertions enabled as per request, no conflicts. */
# define RUBY_DEBUG 1
# define RUBY_NDEBUG 0
# /* keep NDEBUG undefined */
#elif (RBIMPL_NDEBUG == 0) && (RBIMPL_RUBY_DEBUG == 0)
# /* The (*1) situation in avobe diagram. */
# define RUBY_DEBUG 0
# define RUBY_NDEBUG 1
# define NDEBUG
#elif (RBIMPL_NDEBUG == 1) && (RBIMPL_RUBY_DEBUG == 1)
# /* The (*2) situation in above diagram. */
# define RUBY_DEBUG 1
# define RUBY_NDEBUG 0
# /* keep NDEBUG undefined */
# if defined(_MSC_VER)
# pragma message("NDEBUG is ignored because RUBY_DEBUG>0.")
# elif defined(__GNUC__)
# pragma GCC warning "NDEBUG is ignored because RUBY_DEBUG>0."
# else
# error NDEBUG is ignored because RUBY_DEBUG>0.
# endif
#endif
#undef RBIMPL_NDEBUG
#undef RBIMPL_RUBY_DEBUG
/** @cond INTERNAL_MACRO */
#define RBIMPL_ASSERT_NOTHING RBIMPL_CAST((void)0)
RBIMPL_SYMBOL_EXPORT_BEGIN()
RBIMPL_ATTR_NORETURN()
RBIMPL_ATTR_COLD()
void rb_assert_failure(const char *file, int line, const char *name, const char *expr);
RBIMPL_SYMBOL_EXPORT_END()
#ifdef RUBY_FUNCTION_NAME_STRING
# define RBIMPL_ASSERT_FUNC RUBY_FUNCTION_NAME_STRING
#else
# define RBIMPL_ASSERT_FUNC RBIMPL_CAST((const char *)0)
#endif
/** @endcond */
/**
* Prints the given message, and terminates the entire process abnormally.
*
* @param mesg The message to display.
*/
#define RUBY_ASSERT_FAIL(mesg) \
rb_assert_failure(__FILE__, __LINE__, RBIMPL_ASSERT_FUNC, mesg)
/**
* Asserts that the expression is truthy. If not aborts with the message.
*
* @param expr What supposedly evaluates to true.
* @param mesg The message to display on failure.
*/
#define RUBY_ASSERT_MESG(expr, mesg) \
(RB_LIKELY(expr) ? RBIMPL_ASSERT_NOTHING : RUBY_ASSERT_FAIL(mesg))
/**
* A variant of #RUBY_ASSERT that does not interface with #RUBY_DEBUG.
*
* @copydetails #RUBY_ASSERT
*/
#define RUBY_ASSERT_ALWAYS(expr) RUBY_ASSERT_MESG((expr), #expr)
/**
* Asserts that the given expression is truthy if and only if #RUBY_DEBUG is truthy.
*
* @param expr What supposedly evaluates to true.
*/
#if RUBY_DEBUG
# define RUBY_ASSERT(expr) RUBY_ASSERT_MESG((expr), #expr)
#else
# define RUBY_ASSERT(expr) RBIMPL_ASSERT_NOTHING
#endif
/**
* A variant of #RUBY_ASSERT that interfaces with #NDEBUG instead of
* #RUBY_DEBUG. This almost resembles `assert` C standard macro, except minor
* implementation details.
*
* @copydetails #RUBY_ASSERT
*/
/* Currently `RUBY_DEBUG == ! defined(NDEBUG)` is always true. There is no
* difference any longer between this one and `RUBY_ASSERT`. */
#if defined(NDEBUG)
# define RUBY_ASSERT_NDEBUG(expr) RBIMPL_ASSERT_NOTHING
#else
# define RUBY_ASSERT_NDEBUG(expr) RUBY_ASSERT_MESG((expr), #expr)
#endif
/**
* @copydoc #RUBY_ASSERT_WHEN
* @param mesg The message to display on failure.
*/
#if RUBY_DEBUG
# define RUBY_ASSERT_MESG_WHEN(cond, expr, mesg) RUBY_ASSERT_MESG((expr), (mesg))
#else
# define RUBY_ASSERT_MESG_WHEN(cond, expr, mesg) \
((cond) ? RUBY_ASSERT_MESG((expr), (mesg)) : RBIMPL_ASSERT_NOTHING)
#endif
/**
* A variant of #RUBY_ASSERT that asserts when either #RUBY_DEBUG or `cond`
* parameter is truthy.
*
* @param cond Extra condition that shall hold for assertion to take effect.
* @param expr What supposedly evaluates to true.
*/
#define RUBY_ASSERT_WHEN(cond, expr) RUBY_ASSERT_MESG_WHEN((cond), (expr), #expr)
/**
* This is either #RUBY_ASSERT or #RBIMPL_ASSUME, depending on #RUBY_DEBUG.
*
* @copydetails #RUBY_ASSERT
*/
#if RUBY_DEBUG
# define RBIMPL_ASSERT_OR_ASSUME(expr) RUBY_ASSERT_ALWAYS(expr)
#elif RBIMPL_COMPILER_BEFORE(Clang, 7, 0, 0)
# /* See commit 67d259c5dccd31fe49d417fec169977712ffdf10 */
# define RBIMPL_ASSERT_OR_ASSUME(expr) RBIMPL_ASSERT_NOTHING
#elif defined(RUBY_ASSERT_NOASSUME)
# /* See commit d300a734414ef6de7e8eb563b7cc4389c455ed08 */
# define RBIMPL_ASSERT_OR_ASSUME(expr) RBIMPL_ASSERT_NOTHING
#elif ! defined(RBIMPL_HAVE___ASSUME)
# define RBIMPL_ASSERT_OR_ASSUME(expr) RBIMPL_ASSERT_NOTHING
#else
# define RBIMPL_ASSERT_OR_ASSUME(expr) RBIMPL_ASSUME(expr)
#endif
#endif /* RUBY_ASSERT_H */