1 /*
2   Simple DirectMedia Layer
3   Copyright (C) 1997-2025 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_stdinc.h"
26 
27 #include "begin_code.h"
28 /* Set up for C function definitions, even when using C++ */
29 #ifdef __cplusplus
30 extern "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 /*
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.
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 _SDL_HAS_BUILTIN(__builtin_debugtrap)
55     #define SDL_TriggerBreakpoint() __builtin_debugtrap()
56 #elif ( (!defined(__NACL__)) && ((defined(__GNUC__) || defined(__clang__)) && (defined(__i386__) || defined(__x86_64__))) )
57     #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "int $3\n\t" )
58 #elif (defined(__GNUC__) || defined(__clang__)) && defined(__riscv)
59     #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "ebreak\n\t" )
60 #elif ( defined(__APPLE__) && (defined(__arm64__) || defined(__aarch64__)) )  /* this might work on other ARM targets, but this is a known quantity... */
61     #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "brk #22\n\t" )
62 #elif defined(__APPLE__) && defined(__arm__)
63     #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "bkpt #22\n\t" )
64 #elif defined(_WIN32) && ((defined(__GNUC__) || defined(__clang__)) && (defined(__arm64__) || defined(__aarch64__)) )
65     #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "brk #0xF000\n\t" )
66 #elif defined(__386__) && defined(__WATCOMC__)
67     #define SDL_TriggerBreakpoint()
68     { _asm
69     { int 0x03 } }
70 #elif defined(HAVE_SIGNAL_H) && !defined(__WATCOMC__)
71     #include <signal.h>
72     #define SDL_TriggerBreakpoint() raise(SIGTRAP)
73 #else
74     /* How do we trigger breakpoints on this platform? */
75     #define SDL_TriggerBreakpoint()
76 #endif
77 
78 #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 supports __func__ as a standard. */
79 #   define SDL_FUNCTION __func__
80 #elif ((defined(__GNUC__) && (__GNUC__ >= 2)) || defined(_MSC_VER) || defined (__WATCOMC__))
81 #   define SDL_FUNCTION __FUNCTION__
82 #else
83 #   define SDL_FUNCTION "???"
84 #endif
85 #define SDL_FILE    __FILE__
86 #define SDL_LINE    __LINE__
87 
88 /*
89 sizeof (x) makes the compiler still parse the expression even without
90 assertions enabled, so the code is always checked at compile time, but
91 doesn't actually generate code for it, so there are no side effects or
92 expensive checks at run time, just the constant size of what x WOULD be,
93 which presumably gets optimized out as unused.
94 This also solves the problem of...
95 
96     int somevalue = blah();
97     SDL_assert(somevalue == 1);
98 
99 ...which would cause compiles to complain that somevalue is unused if we
100 disable assertions.
101 */
102 
103 /* "while (0,0)" fools Microsoft's compiler's /W4 warning level into thinking
104     this condition isn't constant. And looks like an owl's face! */
105 #ifdef _MSC_VER  /* stupid /W4 warnings. */
106 #define SDL_NULL_WHILE_LOOP_CONDITION (0,0)
107 #else
108 #define SDL_NULL_WHILE_LOOP_CONDITION (0)
109 #endif
110 
111 #define SDL_disabled_assert(condition) \
112     do { (void) sizeof ((condition)); } while (SDL_NULL_WHILE_LOOP_CONDITION)
113 
114 typedef enum
115 {
116     SDL_ASSERTION_RETRY,  /**< Retry the assert immediately. */
117     SDL_ASSERTION_BREAK,  /**< Make the debugger trigger a breakpoint. */
118     SDL_ASSERTION_ABORT,  /**< Terminate the program. */
119     SDL_ASSERTION_IGNORE,  /**< Ignore the assert. */
120     SDL_ASSERTION_ALWAYS_IGNORE  /**< Ignore the assert from now on. */
121 } SDL_AssertState;
122 
123 typedef struct SDL_AssertData
124 {
125     int always_ignore;
126     unsigned int trigger_count;
127     const char *condition;
128     const char *filename;
129     int linenum;
130     const char *function;
131     const struct SDL_AssertData *next;
132 } SDL_AssertData;
133 
134 /* Never call this directly. Use the SDL_assert* macros. */
135 extern DECLSPEC SDL_AssertState SDLCALL SDL_ReportAssertion(SDL_AssertData *,
136                                                             const char *,
137                                                             const char *, int)
138 #if defined(__clang__)
139 #if __has_feature(attribute_analyzer_noreturn)
140 /* this tells Clang's static analysis that we're a custom assert function,
141    and that the analyzer should assume the condition was always true past this
142    SDL_assert test. */
143    __attribute__((analyzer_noreturn))
144 #endif
145 #endif
146 ;
147 
148 /* the do {} while(0) avoids dangling else problems:
149     if (x) SDL_assert(y); else blah();
150        ... without the do/while, the "else" could attach to this macro's "if".
151    We try to handle just the minimum we need here in a macro...the loop,
152    the static vars, and break points. The heavy lifting is handled in
153    SDL_ReportAssertion(), in SDL_assert.c.
154 */
155 #define SDL_enabled_assert(condition) \
156     do { \
157         while ( !(condition) )
158         { \
159             static struct SDL_AssertData sdl_assert_data = { 0, 0, #condition, 0, 0, 0, 0 }; \
160             const SDL_AssertState sdl_assert_state = SDL_ReportAssertion(&sdl_assert_data, SDL_FUNCTION, SDL_FILE, SDL_LINE); \
161             if (sdl_assert_state == SDL_ASSERTION_RETRY)
162             { \
163                 continue; /* go again. */ \
164             } else if (sdl_assert_state == SDL_ASSERTION_BREAK)
165             { \
166                 SDL_TriggerBreakpoint(); \
167             } \
168             break; /* not retrying. */ \
169         } \
170     } while (SDL_NULL_WHILE_LOOP_CONDITION)
171 
172 /* Enable various levels of assertions. */
173 #if SDL_ASSERT_LEVEL == 0   /* assertions disabled */
174 #   define SDL_assert(condition) SDL_disabled_assert(condition)
175 #   define SDL_assert_release(condition) SDL_disabled_assert(condition)
176 #   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
177 #elif SDL_ASSERT_LEVEL == 1  /* release settings. */
178 #   define SDL_assert(condition) SDL_disabled_assert(condition)
179 #   define SDL_assert_release(condition) SDL_enabled_assert(condition)
180 #   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
181 #elif SDL_ASSERT_LEVEL == 2  /* normal settings. */
182 #   define SDL_assert(condition) SDL_enabled_assert(condition)
183 #   define SDL_assert_release(condition) SDL_enabled_assert(condition)
184 #   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
185 #elif SDL_ASSERT_LEVEL == 3  /* paranoid settings. */
186 #   define SDL_assert(condition) SDL_enabled_assert(condition)
187 #   define SDL_assert_release(condition) SDL_enabled_assert(condition)
188 #   define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
189 #else
190 #   error Unknown assertion level.
191 #endif
192 
193 /* this assertion is never disabled at any level. */
194 #define SDL_assert_always(condition) SDL_enabled_assert(condition)
195 
196 
197 /**
198  * A callback that fires when an SDL assertion fails.
199  *
200  * \param data a pointer to the SDL_AssertData structure corresponding to the
201  *             current assertion.
202  * \param userdata what was passed as `userdata` to SDL_SetAssertionHandler().
203  * \returns an SDL_AssertState value indicating how to handle the failure.
204  */
205 typedef SDL_AssertState (SDLCALL *SDL_AssertionHandler)(
206                                  const SDL_AssertData* data, void* userdata);
207 
208 /**
209  * Set an application-defined assertion handler.
210  *
211  * This function allows an application to show its own assertion UI and/or
212  * force the response to an assertion failure. If the application doesn't
213  * provide this, SDL will try to do the right thing, popping up a
214  * system-specific GUI dialog, and probably minimizing any fullscreen windows.
215  *
216  * This callback may fire from any thread, but it runs wrapped in a mutex, so
217  * it will only fire from one thread at a time.
218  *
219  * This callback is NOT reset to SDL's internal handler upon SDL_Quit()!
220  *
221  * \param handler the SDL_AssertionHandler function to call when an assertion
222  *                fails or NULL for the default handler.
223  * \param userdata a pointer that is passed to `handler`.
224  *
225  * \since This function is available since SDL 2.0.0.
226  *
227  * \sa SDL_GetAssertionHandler
228  */
229 extern DECLSPEC void SDLCALL SDL_SetAssertionHandler(
230                                             SDL_AssertionHandler handler,
231                                             void *userdata);
232 
233 /**
234  * Get the default assertion handler.
235  *
236  * This returns the function pointer that is called by default when an
237  * assertion is triggered. This is an internal function provided by SDL, that
238  * is used for assertions when SDL_SetAssertionHandler() hasn't been used to
239  * provide a different function.
240  *
241  * \returns the default SDL_AssertionHandler that is called when an assert
242  *          triggers.
243  *
244  * \since This function is available since SDL 2.0.2.
245  *
246  * \sa SDL_GetAssertionHandler
247  */
248 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetDefaultAssertionHandler(void);
249 
250 /**
251  * Get the current assertion handler.
252  *
253  * This returns the function pointer that is called when an assertion is
254  * triggered. This is either the value last passed to
255  * SDL_SetAssertionHandler(), or if no application-specified function is set,
256  * is equivalent to calling SDL_GetDefaultAssertionHandler().
257  *
258  * The parameter `puserdata` is a pointer to a void*, which will store the
259  * "userdata" pointer that was passed to SDL_SetAssertionHandler(). This value
260  * will always be NULL for the default handler. If you don't care about this
261  * data, it is safe to pass a NULL pointer to this function to ignore it.
262  *
263  * \param puserdata pointer which is filled with the "userdata" pointer that
264  *                  was passed to SDL_SetAssertionHandler().
265  * \returns the SDL_AssertionHandler that is called when an assert triggers.
266  *
267  * \since This function is available since SDL 2.0.2.
268  *
269  * \sa SDL_SetAssertionHandler
270  */
271 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetAssertionHandler(void **puserdata);
272 
273 /**
274  * Get a list of all assertion failures.
275  *
276  * This function gets all assertions triggered since the last call to
277  * SDL_ResetAssertionReport(), or the start of the program.
278  *
279  * The proper way to examine this data looks something like this:
280  *
281  * ```c
282  * const SDL_AssertData *item = SDL_GetAssertionReport();
283  * while (item)
284  {
285  *    printf("'%s', %s (%s:%d), triggered %u times, always ignore: %s.\\n",
286  *           item->condition, item->function, item->filename,
287  *           item->linenum, item->trigger_count,
288  *           item->always_ignore ? "yes" : "no");
289  *    item = item->next;
290  * }
291  * ```
292  *
293  * \returns a list of all failed assertions or NULL if the list is empty. This
294  *          memory should not be modified or freed by the application.
295  *
296  * \since This function is available since SDL 2.0.0.
297  *
298  * \sa SDL_ResetAssertionReport
299  */
300 extern DECLSPEC const SDL_AssertData * SDLCALL SDL_GetAssertionReport(void);
301 
302 /**
303  * Clear the list of all assertion failures.
304  *
305  * This function will clear the list of all assertions triggered up to that
306  * point. Immediately following this call, SDL_GetAssertionReport will return
307  * no items. In addition, any previously-triggered assertions will be reset to
308  * a trigger_count of zero, and their always_ignore state will be false.
309  *
310  * \since This function is available since SDL 2.0.0.
311  *
312  * \sa SDL_GetAssertionReport
313  */
314 extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void);
315 
316 
317 /* these had wrong naming conventions until 2.0.4. Please update your app! */
318 #define SDL_assert_state SDL_AssertState
319 #define SDL_assert_data SDL_AssertData
320 
321 
322 /* Ends C function definitions when using C++ */
323 #ifdef __cplusplus
324 }
325 #endif
326 #include "close_code.h"
327 
328 #endif /* SDL_assert_h_ */
329 
330 /* vi: set ts=4 sw=4 expandtab: */