1/*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2014 Sam Lantinga <slouken@libsdl.org>
4
5  This software is provided 'as-is', without any express or implied
6  warranty.  In no event will the authors be held liable for any damages
7  arising from the use of this software.
8
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12
13  1. The origin of this software must not be misrepresented; you must not
14     claim that you wrote the original software. If you use this software
15     in a product, an acknowledgment in the product documentation would be
16     appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18     misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20*/
21
22#ifndef _SDL_assert_h
23#define _SDL_assert_h
24
25#include "SDL_config.h"
26
27#include "begin_code.h"
28/* Set up for C function definitions, even when using C++ */
29#ifdef __cplusplus
30extern "C" {
31#endif
32
33#ifndef SDL_ASSERT_LEVEL
34#ifdef SDL_DEFAULT_ASSERT_LEVEL
35#define SDL_ASSERT_LEVEL SDL_DEFAULT_ASSERT_LEVEL
36#elif defined(_DEBUG) || defined(DEBUG) || \
37      (defined(__GNUC__) && !defined(__OPTIMIZE__))
38#define SDL_ASSERT_LEVEL 2
39#else
40#define SDL_ASSERT_LEVEL 1
41#endif
42#endif /* SDL_ASSERT_LEVEL */
43
44/*
45These are macros and not first class functions so that the debugger breaks
46on the assertion line and not in some random guts of SDL, and so each
47assert can have unique static variables associated with it.
48*/
49
50#if defined(_MSC_VER)
51/* Don't include intrin.h here because it contains C++ code */
52    extern void __cdecl __debugbreak(void);
53    #define SDL_TriggerBreakpoint() __debugbreak()
54#elif (defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)))
55    #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "int $3\n\t" )
56#elif defined(HAVE_SIGNAL_H)
57    #include <signal.h>
58    #define SDL_TriggerBreakpoint() raise(SIGTRAP)
59#else
60    /* How do we trigger breakpoints on this platform? */
61    #define SDL_TriggerBreakpoint()
62#endif
63
64#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 supports __func__ as a standard. */
65#   define SDL_FUNCTION __func__
66#elif ((__GNUC__ >= 2) || defined(_MSC_VER))
67#   define SDL_FUNCTION __FUNCTION__
68#else
69#   define SDL_FUNCTION "???"
70#endif
71#define SDL_FILE    __FILE__
72#define SDL_LINE    __LINE__
73
74/*
75sizeof (x) makes the compiler still parse the expression even without
76assertions enabled, so the code is always checked at compile time, but
77doesn't actually generate code for it, so there are no side effects or
78expensive checks at run time, just the constant size of what x WOULD be,
79which presumably gets optimized out as unused.
80This also solves the problem of...
81
82    int somevalue = blah();
83    SDL_assert(somevalue == 1);
84
85...which would cause compiles to complain that somevalue is unused if we
86disable assertions.
87*/
88
89#ifdef _MSC_VER  /* stupid /W4 warnings. */
90#define SDL_NULL_WHILE_LOOP_CONDITION (-1 == __LINE__)
91#else
92#define SDL_NULL_WHILE_LOOP_CONDITION (0)
93#endif
94
95#define SDL_disabled_assert(condition) \
96    do { (void) sizeof ((condition)); } while (SDL_NULL_WHILE_LOOP_CONDITION)
97
98typedef enum
99{
100    SDL_ASSERTION_RETRY,  /**< Retry the assert immediately. */
101    SDL_ASSERTION_BREAK,  /**< Make the debugger trigger a breakpoint. */
102    SDL_ASSERTION_ABORT,  /**< Terminate the program. */
103    SDL_ASSERTION_IGNORE,  /**< Ignore the assert. */
104    SDL_ASSERTION_ALWAYS_IGNORE  /**< Ignore the assert from now on. */
105} SDL_assert_state;
106
107typedef struct SDL_assert_data
108{
109    int always_ignore;
110    unsigned int trigger_count;
111    const char *condition;
112    const char *filename;
113    int linenum;
114    const char *function;
115    const struct SDL_assert_data *next;
116} SDL_assert_data;
117
118#if (SDL_ASSERT_LEVEL > 0)
119
120/* Never call this directly. Use the SDL_assert* macros. */
121extern DECLSPEC SDL_assert_state SDLCALL SDL_ReportAssertion(SDL_assert_data *,
122                                                             const char *,
123                                                             const char *, int)
124#if defined(__clang__)
125#if __has_feature(attribute_analyzer_noreturn)
126/* this tells Clang's static analysis that we're a custom assert function,
127   and that the analyzer should assume the condition was always true past this
128   SDL_assert test. */
129   __attribute__((analyzer_noreturn))
130#endif
131#endif
132;
133
134/* the do {} while(0) avoids dangling else problems:
135    if (x) SDL_assert(y); else blah();
136       ... without the do/while, the "else" could attach to this macro's "if".
137   We try to handle just the minimum we need here in a macro...the loop,
138   the static vars, and break points. The heavy lifting is handled in
139   SDL_ReportAssertion(), in SDL_assert.c.
140*/
141#define SDL_enabled_assert(condition) \
142    do { \
143        while ( !(condition) ) { \
144            static struct SDL_assert_data assert_data = { \
145                0, 0, #condition, 0, 0, 0, 0 \
146            }; \
147            const SDL_assert_state state = SDL_ReportAssertion(&assert_data, \
148                                                               SDL_FUNCTION, \
149                                                               SDL_FILE, \
150                                                               SDL_LINE); \
151            if (state == SDL_ASSERTION_RETRY) { \
152                continue; /* go again. */ \
153            } else if (state == SDL_ASSERTION_BREAK) { \
154                SDL_TriggerBreakpoint(); \
155            } \
156            break; /* not retrying. */ \
157        } \
158    } while (SDL_NULL_WHILE_LOOP_CONDITION)
159
160#endif  /* enabled assertions support code */
161
162/* Enable various levels of assertions. */
163#if SDL_ASSERT_LEVEL == 0   /* assertions disabled */
164#   define SDL_assert(condition) SDL_disabled_assert(condition)
165#   define SDL_assert_release(condition) SDL_disabled_assert(condition)
166#   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
167#elif SDL_ASSERT_LEVEL == 1  /* release settings. */
168#   define SDL_assert(condition) SDL_disabled_assert(condition)
169#   define SDL_assert_release(condition) SDL_enabled_assert(condition)
170#   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
171#elif SDL_ASSERT_LEVEL == 2  /* normal settings. */
172#   define SDL_assert(condition) SDL_enabled_assert(condition)
173#   define SDL_assert_release(condition) SDL_enabled_assert(condition)
174#   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
175#elif SDL_ASSERT_LEVEL == 3  /* paranoid settings. */
176#   define SDL_assert(condition) SDL_enabled_assert(condition)
177#   define SDL_assert_release(condition) SDL_enabled_assert(condition)
178#   define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
179#else
180#   error Unknown assertion level.
181#endif
182
183/* this assertion is never disabled at any level. */
184#define SDL_assert_always(condition) SDL_enabled_assert(condition)
185
186
187typedef SDL_assert_state (SDLCALL *SDL_AssertionHandler)(
188                                 const SDL_assert_data* data, void* userdata);
189
190/**
191 *  \brief Set an application-defined assertion handler.
192 *
193 *  This allows an app to show its own assertion UI and/or force the
194 *  response to an assertion failure. If the app doesn't provide this, SDL
195 *  will try to do the right thing, popping up a system-specific GUI dialog,
196 *  and probably minimizing any fullscreen windows.
197 *
198 *  This callback may fire from any thread, but it runs wrapped in a mutex, so
199 *  it will only fire from one thread at a time.
200 *
201 *  Setting the callback to NULL restores SDL's original internal handler.
202 *
203 *  This callback is NOT reset to SDL's internal handler upon SDL_Quit()!
204 *
205 *  \return SDL_assert_state value of how to handle the assertion failure.
206 *
207 *  \param handler Callback function, called when an assertion fails.
208 *  \param userdata A pointer passed to the callback as-is.
209 */
210extern DECLSPEC void SDLCALL SDL_SetAssertionHandler(
211                                            SDL_AssertionHandler handler,
212                                            void *userdata);
213
214/**
215 *  \brief Get the default assertion handler.
216 *
217 *  This returns the function pointer that is called by default when an
218 *   assertion is triggered. This is an internal function provided by SDL,
219 *   that is used for assertions when SDL_SetAssertionHandler() hasn't been
220 *   used to provide a different function.
221 *
222 *  \return The default SDL_AssertionHandler that is called when an assert triggers.
223 */
224extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetDefaultAssertionHandler(void);
225
226/**
227 *  \brief Get the current assertion handler.
228 *
229 *  This returns the function pointer that is called when an assertion is
230 *   triggered. This is either the value last passed to
231 *   SDL_SetAssertionHandler(), or if no application-specified function is
232 *   set, is equivalent to calling SDL_GetDefaultAssertionHandler().
233 *
234 *   \param puserdata Pointer to a void*, which will store the "userdata"
235 *                    pointer that was passed to SDL_SetAssertionHandler().
236 *                    This value will always be NULL for the default handler.
237 *                    If you don't care about this data, it is safe to pass
238 *                    a NULL pointer to this function to ignore it.
239 *  \return The SDL_AssertionHandler that is called when an assert triggers.
240 */
241extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetAssertionHandler(void **puserdata);
242
243/**
244 *  \brief Get a list of all assertion failures.
245 *
246 *  Get all assertions triggered since last call to SDL_ResetAssertionReport(),
247 *  or the start of the program.
248 *
249 *  The proper way to examine this data looks something like this:
250 *
251 *  <code>
252 *  const SDL_assert_data *item = SDL_GetAssertionReport();
253 *  while (item) {
254 *      printf("'%s', %s (%s:%d), triggered %u times, always ignore: %s.\n",
255 *             item->condition, item->function, item->filename,
256 *             item->linenum, item->trigger_count,
257 *             item->always_ignore ? "yes" : "no");
258 *      item = item->next;
259 *  }
260 *  </code>
261 *
262 *  \return List of all assertions.
263 *  \sa SDL_ResetAssertionReport
264 */
265extern DECLSPEC const SDL_assert_data * SDLCALL SDL_GetAssertionReport(void);
266
267/**
268 *  \brief Reset the list of all assertion failures.
269 *
270 *  Reset list of all assertions triggered.
271 *
272 *  \sa SDL_GetAssertionReport
273 */
274extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void);
275
276/* Ends C function definitions when using C++ */
277#ifdef __cplusplus
278}
279#endif
280#include "close_code.h"
281
282#endif /* _SDL_assert_h */
283
284/* vi: set ts=4 sw=4 expandtab: */
285