dep/sdl/include/SDL_assert.h

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