SDL 3.0
SDL_assert.h
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1/*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2023 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/**
23 * \file SDL_assert.h
24 *
25 * \brief Header file for assertion SDL API functions
26 */
27
28#ifndef SDL_assert_h_
29#define SDL_assert_h_
30
31#include <SDL3/SDL_stdinc.h>
32
33#include <SDL3/SDL_begin_code.h>
34/* Set up for C function definitions, even when using C++ */
35#ifdef __cplusplus
36extern "C" {
37#endif
38
39#ifndef SDL_ASSERT_LEVEL
40#ifdef SDL_DEFAULT_ASSERT_LEVEL
41#define SDL_ASSERT_LEVEL SDL_DEFAULT_ASSERT_LEVEL
42#elif defined(_DEBUG) || defined(DEBUG) || \
43 (defined(__GNUC__) && !defined(__OPTIMIZE__))
44#define SDL_ASSERT_LEVEL 2
45#else
46#define SDL_ASSERT_LEVEL 1
47#endif
48#endif /* SDL_ASSERT_LEVEL */
49
50/*
51These are macros and not first class functions so that the debugger breaks
52on the assertion line and not in some random guts of SDL, and so each
53assert can have unique static variables associated with it.
54*/
55
56#ifdef _MSC_VER
57/* Don't include intrin.h here because it contains C++ code */
58 extern void __cdecl __debugbreak(void);
59 #define SDL_TriggerBreakpoint() __debugbreak()
60#elif defined(ANDROID)
61 #include <assert.h>
62 #define SDL_TriggerBreakpoint() assert(0)
63#elif SDL_HAS_BUILTIN(__builtin_debugtrap)
64 #define SDL_TriggerBreakpoint() __builtin_debugtrap()
65#elif (defined(__GNUC__) || defined(__clang__)) && (defined(__i386__) || defined(__x86_64__))
66 #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "int $3\n\t" )
67#elif (defined(__GNUC__) || defined(__clang__)) && defined(__riscv)
68 #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "ebreak\n\t" )
69#elif ( defined(__APPLE__) && (defined(__arm64__) || defined(__aarch64__)) ) /* this might work on other ARM targets, but this is a known quantity... */
70 #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "brk #22\n\t" )
71#elif defined(__APPLE__) && defined(__arm__)
72 #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "bkpt #22\n\t" )
73#elif defined(__386__) && defined(__WATCOMC__)
74 #define SDL_TriggerBreakpoint() { _asm { int 0x03 } }
75#elif defined(HAVE_SIGNAL_H) && !defined(__WATCOMC__)
76 #include <signal.h>
77 #define SDL_TriggerBreakpoint() raise(SIGTRAP)
78#else
79 /* How do we trigger breakpoints on this platform? */
80 #define SDL_TriggerBreakpoint()
81#endif
82
83#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 supports __func__ as a standard. */
84# define SDL_FUNCTION __func__
85#elif ((defined(__GNUC__) && (__GNUC__ >= 2)) || defined(_MSC_VER) || defined (__WATCOMC__))
86# define SDL_FUNCTION __FUNCTION__
87#else
88# define SDL_FUNCTION "???"
89#endif
90#define SDL_FILE __FILE__
91#define SDL_LINE __LINE__
92
93/*
94sizeof (x) makes the compiler still parse the expression even without
95assertions enabled, so the code is always checked at compile time, but
96doesn't actually generate code for it, so there are no side effects or
97expensive checks at run time, just the constant size of what x WOULD be,
98which presumably gets optimized out as unused.
99This also solves the problem of...
100
101 int somevalue = blah();
102 SDL_assert(somevalue == 1);
103
104...which would cause compiles to complain that somevalue is unused if we
105disable assertions.
106*/
107
108/* "while (0,0)" fools Microsoft's compiler's /W4 warning level into thinking
109 this condition isn't constant. And looks like an owl's face! */
110#ifdef _MSC_VER /* stupid /W4 warnings. */
111#define SDL_NULL_WHILE_LOOP_CONDITION (0,0)
112#else
113#define SDL_NULL_WHILE_LOOP_CONDITION (0)
114#endif
115
116#define SDL_disabled_assert(condition) \
117 do { (void) sizeof ((condition)); } while (SDL_NULL_WHILE_LOOP_CONDITION)
118
119typedef enum
120{
121 SDL_ASSERTION_RETRY, /**< Retry the assert immediately. */
122 SDL_ASSERTION_BREAK, /**< Make the debugger trigger a breakpoint. */
123 SDL_ASSERTION_ABORT, /**< Terminate the program. */
124 SDL_ASSERTION_IGNORE, /**< Ignore the assert. */
125 SDL_ASSERTION_ALWAYS_IGNORE /**< Ignore the assert from now on. */
127
128typedef struct SDL_AssertData
129{
131 unsigned int trigger_count;
132 const char *condition;
133 const char *filename;
135 const char *function;
136 const struct SDL_AssertData *next;
138
139/**
140 * Never call this directly.
141 *
142 * Use the SDL_assert* macros.
143 *
144 * \param data assert data structure
145 * \param func function name
146 * \param file file name
147 * \param line line number
148 * \returns assert state
149 *
150 * \since This function is available since SDL 3.0.0.
151 */
153 const char *func,
154 const char *file, int line)
155#ifdef __clang__
156#if __has_feature(attribute_analyzer_noreturn)
157 __attribute__((analyzer_noreturn))
158#endif
159#endif
160;
161/* Previous 'analyzer_noreturn' attribute tells Clang's static analysis that we're a custom assert function,
162 and that the analyzer should assume the condition was always true past this
163 SDL_assert test. */
164
165
166/* Define the trigger breakpoint call used in asserts */
167#ifndef SDL_AssertBreakpoint
168#if defined(ANDROID) && defined(assert)
169/* Define this as empty in case assert() is defined as SDL_assert */
170#define SDL_AssertBreakpoint()
171#else
172#define SDL_AssertBreakpoint() SDL_TriggerBreakpoint()
173#endif
174#endif /* !SDL_AssertBreakpoint */
175
176/* the do {} while(0) avoids dangling else problems:
177 if (x) SDL_assert(y); else blah();
178 ... without the do/while, the "else" could attach to this macro's "if".
179 We try to handle just the minimum we need here in a macro...the loop,
180 the static vars, and break points. The heavy lifting is handled in
181 SDL_ReportAssertion(), in SDL_assert.c.
182*/
183#define SDL_enabled_assert(condition) \
184 do { \
185 while ( !(condition) ) { \
186 static struct SDL_AssertData sdl_assert_data = { 0, 0, #condition, 0, 0, 0, 0 }; \
187 const SDL_AssertState sdl_assert_state = SDL_ReportAssertion(&sdl_assert_data, SDL_FUNCTION, SDL_FILE, SDL_LINE); \
188 if (sdl_assert_state == SDL_ASSERTION_RETRY) { \
189 continue; /* go again. */ \
190 } else if (sdl_assert_state == SDL_ASSERTION_BREAK) { \
191 SDL_AssertBreakpoint(); \
192 } \
193 break; /* not retrying. */ \
194 } \
195 } while (SDL_NULL_WHILE_LOOP_CONDITION)
196
197/* Enable various levels of assertions. */
198#if SDL_ASSERT_LEVEL == 0 /* assertions disabled */
199# define SDL_assert(condition) SDL_disabled_assert(condition)
200# define SDL_assert_release(condition) SDL_disabled_assert(condition)
201# define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
202#elif SDL_ASSERT_LEVEL == 1 /* release settings. */
203# define SDL_assert(condition) SDL_disabled_assert(condition)
204# define SDL_assert_release(condition) SDL_enabled_assert(condition)
205# define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
206#elif SDL_ASSERT_LEVEL == 2 /* normal settings. */
207# define SDL_assert(condition) SDL_enabled_assert(condition)
208# define SDL_assert_release(condition) SDL_enabled_assert(condition)
209# define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
210#elif SDL_ASSERT_LEVEL == 3 /* paranoid settings. */
211# define SDL_assert(condition) SDL_enabled_assert(condition)
212# define SDL_assert_release(condition) SDL_enabled_assert(condition)
213# define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
214#else
215# error Unknown assertion level.
216#endif
217
218/* this assertion is never disabled at any level. */
219#define SDL_assert_always(condition) SDL_enabled_assert(condition)
220
221
222/**
223 * A callback that fires when an SDL assertion fails.
224 *
225 * \param data a pointer to the SDL_AssertData structure corresponding to the
226 * current assertion
227 * \param userdata what was passed as `userdata` to SDL_SetAssertionHandler()
228 * \returns an SDL_AssertState value indicating how to handle the failure.
229 */
231 const SDL_AssertData* data, void* userdata);
232
233/**
234 * Set an application-defined assertion handler.
235 *
236 * This function allows an application to show its own assertion UI and/or
237 * force the response to an assertion failure. If the application doesn't
238 * provide this, SDL will try to do the right thing, popping up a
239 * system-specific GUI dialog, and probably minimizing any fullscreen windows.
240 *
241 * This callback may fire from any thread, but it runs wrapped in a mutex, so
242 * it will only fire from one thread at a time.
243 *
244 * This callback is NOT reset to SDL's internal handler upon SDL_Quit()!
245 *
246 * \param handler the SDL_AssertionHandler function to call when an assertion
247 * fails or NULL for the default handler
248 * \param userdata a pointer that is passed to `handler`
249 *
250 * \since This function is available since SDL 3.0.0.
251 *
252 * \sa SDL_GetAssertionHandler
253 */
254extern DECLSPEC void SDLCALL SDL_SetAssertionHandler(
255 SDL_AssertionHandler handler,
256 void *userdata);
257
258/**
259 * Get the default assertion handler.
260 *
261 * This returns the function pointer that is called by default when an
262 * assertion is triggered. This is an internal function provided by SDL, that
263 * is used for assertions when SDL_SetAssertionHandler() hasn't been used to
264 * provide a different function.
265 *
266 * \returns the default SDL_AssertionHandler that is called when an assert
267 * triggers.
268 *
269 * \since This function is available since SDL 3.0.0.
270 *
271 * \sa SDL_GetAssertionHandler
272 */
274
275/**
276 * Get the current assertion handler.
277 *
278 * This returns the function pointer that is called when an assertion is
279 * triggered. This is either the value last passed to
280 * SDL_SetAssertionHandler(), or if no application-specified function is set,
281 * is equivalent to calling SDL_GetDefaultAssertionHandler().
282 *
283 * The parameter `puserdata` is a pointer to a void*, which will store the
284 * "userdata" pointer that was passed to SDL_SetAssertionHandler(). This value
285 * will always be NULL for the default handler. If you don't care about this
286 * data, it is safe to pass a NULL pointer to this function to ignore it.
287 *
288 * \param puserdata pointer which is filled with the "userdata" pointer that
289 * was passed to SDL_SetAssertionHandler()
290 * \returns the SDL_AssertionHandler that is called when an assert triggers.
291 *
292 * \since This function is available since SDL 3.0.0.
293 *
294 * \sa SDL_SetAssertionHandler
295 */
296extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetAssertionHandler(void **puserdata);
297
298/**
299 * Get a list of all assertion failures.
300 *
301 * This function gets all assertions triggered since the last call to
302 * SDL_ResetAssertionReport(), or the start of the program.
303 *
304 * The proper way to examine this data looks something like this:
305 *
306 * ```c
307 * const SDL_AssertData *item = SDL_GetAssertionReport();
308 * while (item) {
309 * printf("'%s', %s (%s:%d), triggered %u times, always ignore: %s.\\n",
310 * item->condition, item->function, item->filename,
311 * item->linenum, item->trigger_count,
312 * item->always_ignore ? "yes" : "no");
313 * item = item->next;
314 * }
315 * ```
316 *
317 * \returns a list of all failed assertions or NULL if the list is empty. This
318 * memory should not be modified or freed by the application.
319 *
320 * \since This function is available since SDL 3.0.0.
321 *
322 * \sa SDL_ResetAssertionReport
323 */
324extern DECLSPEC const SDL_AssertData * SDLCALL SDL_GetAssertionReport(void);
325
326/**
327 * Clear the list of all assertion failures.
328 *
329 * This function will clear the list of all assertions triggered up to that
330 * point. Immediately following this call, SDL_GetAssertionReport will return
331 * no items. In addition, any previously-triggered assertions will be reset to
332 * a trigger_count of zero, and their always_ignore state will be false.
333 *
334 * \since This function is available since SDL 3.0.0.
335 *
336 * \sa SDL_GetAssertionReport
337 */
338extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void);
339
340/* Ends C function definitions when using C++ */
341#ifdef __cplusplus
342}
343#endif
344#include <SDL3/SDL_close_code.h>
345
346#endif /* SDL_assert_h_ */
SDL_AssertState
Definition: SDL_assert.h:120
@ SDL_ASSERTION_RETRY
Definition: SDL_assert.h:121
@ SDL_ASSERTION_ABORT
Definition: SDL_assert.h:123
@ SDL_ASSERTION_IGNORE
Definition: SDL_assert.h:124
@ SDL_ASSERTION_BREAK
Definition: SDL_assert.h:122
@ SDL_ASSERTION_ALWAYS_IGNORE
Definition: SDL_assert.h:125
SDL_AssertState SDL_ReportAssertion(SDL_AssertData *data, const char *func, const char *file, int line)
SDL_AssertState(* SDL_AssertionHandler)(const SDL_AssertData *data, void *userdata)
Definition: SDL_assert.h:230
const SDL_AssertData * SDL_GetAssertionReport(void)
void SDL_ResetAssertionReport(void)
void SDL_SetAssertionHandler(SDL_AssertionHandler handler, void *userdata)
SDL_AssertionHandler SDL_GetDefaultAssertionHandler(void)
SDL_AssertionHandler SDL_GetAssertionHandler(void **puserdata)
This is a general header that includes C language support.
const struct SDL_AssertData * next
Definition: SDL_assert.h:136
unsigned int trigger_count
Definition: SDL_assert.h:131
const char * function
Definition: SDL_assert.h:135
const char * filename
Definition: SDL_assert.h:133
const char * condition
Definition: SDL_assert.h:132