2 Simple DirectMedia Layer
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.
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:
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.
25 #include "SDL_config.h"
27 #include "begin_code.h"
28 /* Set up for C function definitions, even when using C++ */
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
40 #define SDL_ASSERT_LEVEL 1
42 #endif /* SDL_ASSERT_LEVEL */
45 These are macros and not first class functions so that the debugger breaks
46 on the assertion line and not in some random guts of SDL, and so each
47 assert can have unique static variables associated with it.
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)
58 #define SDL_TriggerBreakpoint() raise(SIGTRAP)
60 /* How do we trigger breakpoints on this platform? */
61 #define SDL_TriggerBreakpoint()
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__
69 # define SDL_FUNCTION "???"
71 #define SDL_FILE __FILE__
72 #define SDL_LINE __LINE__
75 sizeof (x) makes the compiler still parse the expression even without
76 assertions enabled, so the code is always checked at compile time, but
77 doesn't actually generate code for it, so there are no side effects or
78 expensive checks at run time, just the constant size of what x WOULD be,
79 which presumably gets optimized out as unused.
80 This also solves the problem of...
82 int somevalue = blah();
83 SDL_assert(somevalue == 1);
85 ...which would cause compiles to complain that somevalue is unused if we
89 #ifdef _MSC_VER /* stupid /W4 warnings. */
90 #define SDL_NULL_WHILE_LOOP_CONDITION (-1 == __LINE__)
92 #define SDL_NULL_WHILE_LOOP_CONDITION (0)
95 #define SDL_disabled_assert(condition) \
96 do { (void) sizeof ((condition)); } while (SDL_NULL_WHILE_LOOP_CONDITION)
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. */
107 typedef struct SDL_assert_data
110 unsigned int trigger_count;
111 const char *condition;
112 const char *filename;
114 const char *function;
115 const struct SDL_assert_data *next;
118 #if (SDL_ASSERT_LEVEL > 0)
120 /* Never call this directly. Use the SDL_assert* macros. */
121 extern DECLSPEC SDL_assert_state SDLCALL SDL_ReportAssertion(SDL_assert_data *,
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
129 __attribute__((analyzer_noreturn))
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.
141 #define SDL_enabled_assert(condition) \
143 while ( !(condition) ) { \
144 static struct SDL_assert_data assert_data = { \
145 0, 0, #condition, 0, 0, 0, 0 \
147 const SDL_assert_state state = SDL_ReportAssertion(&assert_data, \
151 if (state == SDL_ASSERTION_RETRY) { \
152 continue; /* go again. */ \
153 } else if (state == SDL_ASSERTION_BREAK) { \
154 SDL_TriggerBreakpoint(); \
156 break; /* not retrying. */ \
158 } while (SDL_NULL_WHILE_LOOP_CONDITION)
160 #endif /* enabled assertions support code */
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)
180 # error Unknown assertion level.
183 /* this assertion is never disabled at any level. */
184 #define SDL_assert_always(condition) SDL_enabled_assert(condition)
187 typedef SDL_assert_state (SDLCALL *SDL_AssertionHandler)(
188 const SDL_assert_data* data, void* userdata);
191 * \brief Set an application-defined assertion handler.
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.
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.
201 * Setting the callback to NULL restores SDL's original internal handler.
203 * This callback is NOT reset to SDL's internal handler upon SDL_Quit()!
205 * \return SDL_assert_state value of how to handle the assertion failure.
207 * \param handler Callback function, called when an assertion fails.
208 * \param userdata A pointer passed to the callback as-is.
210 extern DECLSPEC void SDLCALL SDL_SetAssertionHandler(
211 SDL_AssertionHandler handler,
215 * \brief Get the default assertion handler.
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.
222 * \return The default SDL_AssertionHandler that is called when an assert triggers.
224 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetDefaultAssertionHandler(void);
227 * \brief Get the current assertion handler.
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().
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.
241 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetAssertionHandler(void **puserdata);
244 * \brief Get a list of all assertion failures.
246 * Get all assertions triggered since last call to SDL_ResetAssertionReport(),
247 * or the start of the program.
249 * The proper way to examine this data looks something like this:
252 * const SDL_assert_data *item = SDL_GetAssertionReport();
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");
262 * \return List of all assertions.
263 * \sa SDL_ResetAssertionReport
265 extern DECLSPEC const SDL_assert_data * SDLCALL SDL_GetAssertionReport(void);
268 * \brief Reset the list of all assertion failures.
270 * Reset list of all assertions triggered.
272 * \sa SDL_GetAssertionReport
274 extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void);
276 /* Ends C function definitions when using C++ */
280 #include "close_code.h"
282 #endif /* _SDL_assert_h */
284 /* vi: set ts=4 sw=4 expandtab: */