1 /* 2 Simple DirectMedia Layer 3 Copyright (C) 1997-2020 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_config.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 ( (!defined(__NACL__)) && ((defined(__GNUC__) || defined(__clang__)) && (defined(__i386__) || defined(__x86_64__))) ) 55 #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "int $3\n\t" ) 56 #elif defined(__386__) && defined(__WATCOMC__) 57 #define SDL_TriggerBreakpoint() { _asm { int 0x03 } } 58 #elif defined(HAVE_SIGNAL_H) && !defined(__WATCOMC__) 59 #include <signal.h> 60 #define SDL_TriggerBreakpoint() raise(SIGTRAP) 61 #else 62 /* How do we trigger breakpoints on this platform? */ 63 #define SDL_TriggerBreakpoint() 64 #endif 65 66 #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 supports __func__ as a standard. */ 67 # define SDL_FUNCTION __func__ 68 #elif ((__GNUC__ >= 2) || defined(_MSC_VER) || defined (__WATCOMC__)) 69 # define SDL_FUNCTION __FUNCTION__ 70 #else 71 # define SDL_FUNCTION "???" 72 #endif 73 #define SDL_FILE __FILE__ 74 #define SDL_LINE __LINE__ 75 76 /* 77 sizeof (x) makes the compiler still parse the expression even without 78 assertions enabled, so the code is always checked at compile time, but 79 doesn't actually generate code for it, so there are no side effects or 80 expensive checks at run time, just the constant size of what x WOULD be, 81 which presumably gets optimized out as unused. 82 This also solves the problem of... 83 84 int somevalue = blah(); 85 SDL_assert(somevalue == 1); 86 87 ...which would cause compiles to complain that somevalue is unused if we 88 disable assertions. 89 */ 90 91 /* "while (0,0)" fools Microsoft's compiler's /W4 warning level into thinking 92 this condition isn't constant. And looks like an owl's face! */ 93 #ifdef _MSC_VER /* stupid /W4 warnings. */ 94 #define SDL_NULL_WHILE_LOOP_CONDITION (0,0) 95 #else 96 #define SDL_NULL_WHILE_LOOP_CONDITION (0) 97 #endif 98 99 #define SDL_disabled_assert(condition) \ 100 do { (void) sizeof ((condition)); } while (SDL_NULL_WHILE_LOOP_CONDITION) 101 102 typedef enum 103 { 104 SDL_ASSERTION_RETRY, /**< Retry the assert immediately. */ 105 SDL_ASSERTION_BREAK, /**< Make the debugger trigger a breakpoint. */ 106 SDL_ASSERTION_ABORT, /**< Terminate the program. */ 107 SDL_ASSERTION_IGNORE, /**< Ignore the assert. */ 108 SDL_ASSERTION_ALWAYS_IGNORE /**< Ignore the assert from now on. */ 109 } SDL_AssertState; 110 111 typedef struct SDL_AssertData 112 { 113 int always_ignore; 114 unsigned int trigger_count; 115 const char *condition; 116 const char *filename; 117 int linenum; 118 const char *function; 119 const struct SDL_AssertData *next; 120 } SDL_AssertData; 121 122 #if (SDL_ASSERT_LEVEL > 0) 123 124 /* Never call this directly. Use the SDL_assert* macros. */ 125 extern DECLSPEC SDL_AssertState SDLCALL SDL_ReportAssertion(SDL_AssertData *, 126 const char *, 127 const char *, int) 128 #if defined(__clang__) 129 #if __has_feature(attribute_analyzer_noreturn) 130 /* this tells Clang's static analysis that we're a custom assert function, 131 and that the analyzer should assume the condition was always true past this 132 SDL_assert test. */ 133 __attribute__((analyzer_noreturn)) 134 #endif 135 #endif 136 ; 137 138 /* the do {} while(0) avoids dangling else problems: 139 if (x) SDL_assert(y); else blah(); 140 ... without the do/while, the "else" could attach to this macro's "if". 141 We try to handle just the minimum we need here in a macro...the loop, 142 the static vars, and break points. The heavy lifting is handled in 143 SDL_ReportAssertion(), in SDL_assert.c. 144 */ 145 #define SDL_enabled_assert(condition) \ 146 do { \ 147 while ( !(condition) ) { \ 148 static struct SDL_AssertData sdl_assert_data = { \ 149 0, 0, #condition, 0, 0, 0, 0 \ 150 }; \ 151 const SDL_AssertState sdl_assert_state = SDL_ReportAssertion(&sdl_assert_data, SDL_FUNCTION, SDL_FILE, SDL_LINE); \ 152 if (sdl_assert_state == SDL_ASSERTION_RETRY) { \ 153 continue; /* go again. */ \ 154 } else if (sdl_assert_state == SDL_ASSERTION_BREAK) { \ 155 SDL_TriggerBreakpoint(); \ 156 } \ 157 break; /* not retrying. */ \ 158 } \ 159 } while (SDL_NULL_WHILE_LOOP_CONDITION) 160 161 #endif /* enabled assertions support code */ 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 typedef SDL_AssertState (SDLCALL *SDL_AssertionHandler)( 189 const SDL_AssertData* data, void* userdata); 190 191 /** 192 * \brief Set an application-defined assertion handler. 193 * 194 * This allows an app to show its own assertion UI and/or force the 195 * response to an assertion failure. If the app doesn't provide this, SDL 196 * will try to do the right thing, popping up a system-specific GUI dialog, 197 * and probably minimizing any fullscreen windows. 198 * 199 * This callback may fire from any thread, but it runs wrapped in a mutex, so 200 * it will only fire from one thread at a time. 201 * 202 * Setting the callback to NULL restores SDL's original internal handler. 203 * 204 * This callback is NOT reset to SDL's internal handler upon SDL_Quit()! 205 * 206 * Return SDL_AssertState value of how to handle the assertion failure. 207 * 208 * \param handler Callback function, called when an assertion fails. 209 * \param userdata A pointer passed to the callback as-is. 210 */ 211 extern DECLSPEC void SDLCALL SDL_SetAssertionHandler( 212 SDL_AssertionHandler handler, 213 void *userdata); 214 215 /** 216 * \brief Get the default assertion handler. 217 * 218 * This returns the function pointer that is called by default when an 219 * assertion is triggered. This is an internal function provided by SDL, 220 * that is used for assertions when SDL_SetAssertionHandler() hasn't been 221 * used to provide a different function. 222 * 223 * \return The default SDL_AssertionHandler that is called when an assert triggers. 224 */ 225 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetDefaultAssertionHandler(void); 226 227 /** 228 * \brief Get the current assertion handler. 229 * 230 * This returns the function pointer that is called when an assertion is 231 * triggered. This is either the value last passed to 232 * SDL_SetAssertionHandler(), or if no application-specified function is 233 * set, is equivalent to calling SDL_GetDefaultAssertionHandler(). 234 * 235 * \param puserdata Pointer to a void*, which will store the "userdata" 236 * pointer that was passed to SDL_SetAssertionHandler(). 237 * This value will always be NULL for the default handler. 238 * If you don't care about this data, it is safe to pass 239 * a NULL pointer to this function to ignore it. 240 * \return The SDL_AssertionHandler that is called when an assert triggers. 241 */ 242 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetAssertionHandler(void **puserdata); 243 244 /** 245 * \brief Get a list of all assertion failures. 246 * 247 * Get all assertions triggered since last call to SDL_ResetAssertionReport(), 248 * or the start of the program. 249 * 250 * The proper way to examine this data looks something like this: 251 * 252 * <code> 253 * const SDL_AssertData *item = SDL_GetAssertionReport(); 254 * while (item) { 255 * printf("'%s', %s (%s:%d), triggered %u times, always ignore: %s.\\n", 256 * item->condition, item->function, item->filename, 257 * item->linenum, item->trigger_count, 258 * item->always_ignore ? "yes" : "no"); 259 * item = item->next; 260 * } 261 * </code> 262 * 263 * \return List of all assertions. 264 * \sa SDL_ResetAssertionReport 265 */ 266 extern DECLSPEC const SDL_AssertData * SDLCALL SDL_GetAssertionReport(void); 267 268 /** 269 * \brief Reset the list of all assertion failures. 270 * 271 * Reset list of all assertions triggered. 272 * 273 * \sa SDL_GetAssertionReport 274 */ 275 extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void); 276 277 278 /* these had wrong naming conventions until 2.0.4. Please update your app! */ 279 #define SDL_assert_state SDL_AssertState 280 #define SDL_assert_data SDL_AssertData 281 282 283 /* Ends C function definitions when using C++ */ 284 #ifdef __cplusplus 285 } 286 #endif 287 #include "close_code.h" 288 289 #endif /* SDL_assert_h_ */ 290 291 /* vi: set ts=4 sw=4 expandtab: */ 292