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#if defined(_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(__APPLE__) && (defined(__arm64__) || defined(__aarch64__)) ) /* this might work on other ARM targets, but this is a known quantity... */
68 #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "brk #22\n\t" )
69#elif defined(__APPLE__) && defined(__arm__)
70 #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "bkpt #22\n\t" )
71#elif defined(__386__) && defined(__WATCOMC__)
72 #define SDL_TriggerBreakpoint() { _asm { int 0x03 } }
73#elif defined(HAVE_SIGNAL_H) && !defined(__WATCOMC__)
74 #include <signal.h>
75 #define SDL_TriggerBreakpoint() raise(SIGTRAP)
76#else
77 /* How do we trigger breakpoints on this platform? */
78 #define SDL_TriggerBreakpoint()
79#endif
80
81#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 supports __func__ as a standard. */
82# define SDL_FUNCTION __func__
83#elif ((defined(__GNUC__) && (__GNUC__ >= 2)) || defined(_MSC_VER) || defined (__WATCOMC__))
84# define SDL_FUNCTION __FUNCTION__
85#else
86# define SDL_FUNCTION "???"
87#endif
88#define SDL_FILE __FILE__
89#define SDL_LINE __LINE__
90
91/*
92sizeof (x) makes the compiler still parse the expression even without
93assertions enabled, so the code is always checked at compile time, but
94doesn't actually generate code for it, so there are no side effects or
95expensive checks at run time, just the constant size of what x WOULD be,
96which presumably gets optimized out as unused.
97This also solves the problem of...
98
99 int somevalue = blah();
100 SDL_assert(somevalue == 1);
101
102...which would cause compiles to complain that somevalue is unused if we
103disable assertions.
104*/
105
106/* "while (0,0)" fools Microsoft's compiler's /W4 warning level into thinking
107 this condition isn't constant. And looks like an owl's face! */
108#ifdef _MSC_VER /* stupid /W4 warnings. */
109#define SDL_NULL_WHILE_LOOP_CONDITION (0,0)
110#else
111#define SDL_NULL_WHILE_LOOP_CONDITION (0)
112#endif
113
114#define SDL_disabled_assert(condition) \
115 do { (void) sizeof ((condition)); } while (SDL_NULL_WHILE_LOOP_CONDITION)
116
117typedef enum
118{
119 SDL_ASSERTION_RETRY, /**< Retry the assert immediately. */
120 SDL_ASSERTION_BREAK, /**< Make the debugger trigger a breakpoint. */
121 SDL_ASSERTION_ABORT, /**< Terminate the program. */
122 SDL_ASSERTION_IGNORE, /**< Ignore the assert. */
123 SDL_ASSERTION_ALWAYS_IGNORE /**< Ignore the assert from now on. */
125
126typedef struct SDL_AssertData
127{
129 unsigned int trigger_count;
130 const char *condition;
131 const char *filename;
133 const char *function;
134 const struct SDL_AssertData *next;
136
137#if (SDL_ASSERT_LEVEL > 0)
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#if defined(__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 = { \
187 0, 0, #condition, 0, 0, 0, 0 \
188 }; \
189 const SDL_AssertState sdl_assert_state = SDL_ReportAssertion(&sdl_assert_data, SDL_FUNCTION, SDL_FILE, SDL_LINE); \
190 if (sdl_assert_state == SDL_ASSERTION_RETRY) { \
191 continue; /* go again. */ \
192 } else if (sdl_assert_state == SDL_ASSERTION_BREAK) { \
193 SDL_AssertBreakpoint(); \
194 } \
195 break; /* not retrying. */ \
196 } \
197 } while (SDL_NULL_WHILE_LOOP_CONDITION)
198
199#endif /* enabled assertions support code */
200
201/* Enable various levels of assertions. */
202#if SDL_ASSERT_LEVEL == 0 /* assertions disabled */
203# define SDL_assert(condition) SDL_disabled_assert(condition)
204# define SDL_assert_release(condition) SDL_disabled_assert(condition)
205# define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
206#elif SDL_ASSERT_LEVEL == 1 /* release settings. */
207# define SDL_assert(condition) SDL_disabled_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 == 2 /* normal 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_disabled_assert(condition)
214#elif SDL_ASSERT_LEVEL == 3 /* paranoid settings. */
215# define SDL_assert(condition) SDL_enabled_assert(condition)
216# define SDL_assert_release(condition) SDL_enabled_assert(condition)
217# define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
218#else
219# error Unknown assertion level.
220#endif
221
222/* this assertion is never disabled at any level. */
223#define SDL_assert_always(condition) SDL_enabled_assert(condition)
224
225
226/**
227 * A callback that fires when an SDL assertion fails.
228 *
229 * \param data a pointer to the SDL_AssertData structure corresponding to the
230 * current assertion
231 * \param userdata what was passed as `userdata` to SDL_SetAssertionHandler()
232 * \returns an SDL_AssertState value indicating how to handle the failure.
233 */
235 const SDL_AssertData* data, void* userdata);
236
237/**
238 * Set an application-defined assertion handler.
239 *
240 * This function allows an application to show its own assertion UI and/or
241 * force the response to an assertion failure. If the application doesn't
242 * provide this, SDL will try to do the right thing, popping up a
243 * system-specific GUI dialog, and probably minimizing any fullscreen windows.
244 *
245 * This callback may fire from any thread, but it runs wrapped in a mutex, so
246 * it will only fire from one thread at a time.
247 *
248 * This callback is NOT reset to SDL's internal handler upon SDL_Quit()!
249 *
250 * \param handler the SDL_AssertionHandler function to call when an assertion
251 * fails or NULL for the default handler
252 * \param userdata a pointer that is passed to `handler`
253 *
254 * \since This function is available since SDL 3.0.0.
255 *
256 * \sa SDL_GetAssertionHandler
257 */
258extern DECLSPEC void SDLCALL SDL_SetAssertionHandler(
259 SDL_AssertionHandler handler,
260 void *userdata);
261
262/**
263 * Get the default assertion handler.
264 *
265 * This returns the function pointer that is called by default when an
266 * assertion is triggered. This is an internal function provided by SDL, that
267 * is used for assertions when SDL_SetAssertionHandler() hasn't been used to
268 * provide a different function.
269 *
270 * \returns the default SDL_AssertionHandler that is called when an assert
271 * triggers.
272 *
273 * \since This function is available since SDL 3.0.0.
274 *
275 * \sa SDL_GetAssertionHandler
276 */
278
279/**
280 * Get the current assertion handler.
281 *
282 * This returns the function pointer that is called when an assertion is
283 * triggered. This is either the value last passed to
284 * SDL_SetAssertionHandler(), or if no application-specified function is set,
285 * is equivalent to calling SDL_GetDefaultAssertionHandler().
286 *
287 * The parameter `puserdata` is a pointer to a void*, which will store the
288 * "userdata" pointer that was passed to SDL_SetAssertionHandler(). This value
289 * will always be NULL for the default handler. If you don't care about this
290 * data, it is safe to pass a NULL pointer to this function to ignore it.
291 *
292 * \param puserdata pointer which is filled with the "userdata" pointer that
293 * was passed to SDL_SetAssertionHandler()
294 * \returns the SDL_AssertionHandler that is called when an assert triggers.
295 *
296 * \since This function is available since SDL 3.0.0.
297 *
298 * \sa SDL_SetAssertionHandler
299 */
300extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetAssertionHandler(void **puserdata);
301
302/**
303 * Get a list of all assertion failures.
304 *
305 * This function gets all assertions triggered since the last call to
306 * SDL_ResetAssertionReport(), or the start of the program.
307 *
308 * The proper way to examine this data looks something like this:
309 *
310 * ```c
311 * const SDL_AssertData *item = SDL_GetAssertionReport();
312 * while (item) {
313 * printf("'%s', %s (%s:%d), triggered %u times, always ignore: %s.\\n",
314 * item->condition, item->function, item->filename,
315 * item->linenum, item->trigger_count,
316 * item->always_ignore ? "yes" : "no");
317 * item = item->next;
318 * }
319 * ```
320 *
321 * \returns a list of all failed assertions or NULL if the list is empty. This
322 * memory should not be modified or freed by the application.
323 *
324 * \since This function is available since SDL 3.0.0.
325 *
326 * \sa SDL_ResetAssertionReport
327 */
328extern DECLSPEC const SDL_AssertData * SDLCALL SDL_GetAssertionReport(void);
329
330/**
331 * Clear the list of all assertion failures.
332 *
333 * This function will clear the list of all assertions triggered up to that
334 * point. Immediately following this call, SDL_GetAssertionReport will return
335 * no items. In addition, any previously-triggered assertions will be reset to
336 * a trigger_count of zero, and their always_ignore state will be false.
337 *
338 * \since This function is available since SDL 3.0.0.
339 *
340 * \sa SDL_GetAssertionReport
341 */
342extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void);
343
344/* Ends C function definitions when using C++ */
345#ifdef __cplusplus
346}
347#endif
348#include <SDL3/SDL_close_code.h>
349
350#endif /* SDL_assert_h_ */
SDL_AssertState
Definition: SDL_assert.h:118
@ SDL_ASSERTION_RETRY
Definition: SDL_assert.h:119
@ SDL_ASSERTION_ABORT
Definition: SDL_assert.h:121
@ SDL_ASSERTION_IGNORE
Definition: SDL_assert.h:122
@ SDL_ASSERTION_BREAK
Definition: SDL_assert.h:120
@ SDL_ASSERTION_ALWAYS_IGNORE
Definition: SDL_assert.h:123
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:234
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:134
unsigned int trigger_count
Definition: SDL_assert.h:129
const char * function
Definition: SDL_assert.h:133
const char * filename
Definition: SDL_assert.h:131
const char * condition
Definition: SDL_assert.h:130