1 /* 2 Simple DirectMedia Layer 3 Copyright (C) 1997-2016 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(__i386__) || defined(__x86_64__))) 55 #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "int $3\n\t" ) 56 #elif defined(HAVE_SIGNAL_H) 57 #include <signal.h> 58 #define SDL_TriggerBreakpoint() raise(SIGTRAP) 59 #else 60 /* How do we trigger breakpoints on this platform? */ 61 #define SDL_TriggerBreakpoint() 62 #endif 63 64 #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 supports __func__ as a standard. */ 65 # define SDL_FUNCTION __func__ 66 #elif ((__GNUC__ >= 2) || defined(_MSC_VER)) 67 # define SDL_FUNCTION __FUNCTION__ 68 #else 69 # define SDL_FUNCTION "???" 70 #endif 71 #define SDL_FILE __FILE__ 72 #define SDL_LINE __LINE__ 73 74 /* 75 sizeof (x) makes the compiler still parse the expression even without 76 assertions enabled, so the code is always checked at compile time, but 77 doesn't actually generate code for it, so there are no side effects or 78 expensive checks at run time, just the constant size of what x WOULD be, 79 which presumably gets optimized out as unused. 80 This also solves the problem of... 81 82 int somevalue = blah(); 83 SDL_assert(somevalue == 1); 84 85 ...which would cause compiles to complain that somevalue is unused if we 86 disable assertions. 87 */ 88 89 /* "while (0,0)" fools Microsoft's compiler's /W4 warning level into thinking 90 this condition isn't constant. And looks like an owl's face! */ 91 #ifdef _MSC_VER /* stupid /W4 warnings. */ 92 #define SDL_NULL_WHILE_LOOP_CONDITION (0,0) 93 #else 94 #define SDL_NULL_WHILE_LOOP_CONDITION (0) 95 #endif 96 97 #define SDL_disabled_assert(condition) \ 98 do { (void) sizeof ((condition)); } while (SDL_NULL_WHILE_LOOP_CONDITION) 99 100 typedef enum 101 { 102 SDL_ASSERTION_RETRY, /**< Retry the assert immediately. */ 103 SDL_ASSERTION_BREAK, /**< Make the debugger trigger a breakpoint. */ 104 SDL_ASSERTION_ABORT, /**< Terminate the program. */ 105 SDL_ASSERTION_IGNORE, /**< Ignore the assert. */ 106 SDL_ASSERTION_ALWAYS_IGNORE /**< Ignore the assert from now on. */ 107 } SDL_AssertState; 108 109 typedef struct SDL_AssertData 110 { 111 int always_ignore; 112 unsigned int trigger_count; 113 const char *condition; 114 const char *filename; 115 int linenum; 116 const char *function; 117 const struct SDL_AssertData *next; 118 } SDL_AssertData; 119 120 #if (SDL_ASSERT_LEVEL > 0) 121 122 /* Never call this directly. Use the SDL_assert* macros. */ 123 extern DECLSPEC SDL_AssertState SDLCALL SDL_ReportAssertion(SDL_AssertData *, 124 const char *, 125 const char *, int) 126 #if defined(__clang__) 127 #if __has_feature(attribute_analyzer_noreturn) 128 /* this tells Clang's static analysis that we're a custom assert function, 129 and that the analyzer should assume the condition was always true past this 130 SDL_assert test. */ 131 __attribute__((analyzer_noreturn)) 132 #endif 133 #endif 134 ; 135 136 /* the do {} while(0) avoids dangling else problems: 137 if (x) SDL_assert(y); else blah(); 138 ... without the do/while, the "else" could attach to this macro's "if". 139 We try to handle just the minimum we need here in a macro...the loop, 140 the static vars, and break points. The heavy lifting is handled in 141 SDL_ReportAssertion(), in SDL_assert.c. 142 */ 143 #define SDL_enabled_assert(condition) \ 144 do { \ 145 while ( !(condition) ) { \ 146 static struct SDL_AssertData sdl_assert_data = { \ 147 0, 0, #condition, 0, 0, 0, 0 \ 148 }; \ 149 const SDL_AssertState sdl_assert_state = SDL_ReportAssertion(&sdl_assert_data, SDL_FUNCTION, SDL_FILE, SDL_LINE); \ 150 if (sdl_assert_state == SDL_ASSERTION_RETRY) { \ 151 continue; /* go again. */ \ 152 } else if (sdl_assert_state == SDL_ASSERTION_BREAK) { \ 153 SDL_TriggerBreakpoint(); \ 154 } \ 155 break; /* not retrying. */ \ 156 } \ 157 } while (SDL_NULL_WHILE_LOOP_CONDITION) 158 159 #endif /* enabled assertions support code */ 160 161 /* Enable various levels of assertions. */ 162 #if SDL_ASSERT_LEVEL == 0 /* assertions disabled */ 163 # define SDL_assert(condition) SDL_disabled_assert(condition) 164 # define SDL_assert_release(condition) SDL_disabled_assert(condition) 165 # define SDL_assert_paranoid(condition) SDL_disabled_assert(condition) 166 #elif SDL_ASSERT_LEVEL == 1 /* release settings. */ 167 # define SDL_assert(condition) SDL_disabled_assert(condition) 168 # define SDL_assert_release(condition) SDL_enabled_assert(condition) 169 # define SDL_assert_paranoid(condition) SDL_disabled_assert(condition) 170 #elif SDL_ASSERT_LEVEL == 2 /* normal settings. */ 171 # define SDL_assert(condition) SDL_enabled_assert(condition) 172 # define SDL_assert_release(condition) SDL_enabled_assert(condition) 173 # define SDL_assert_paranoid(condition) SDL_disabled_assert(condition) 174 #elif SDL_ASSERT_LEVEL == 3 /* paranoid settings. */ 175 # define SDL_assert(condition) SDL_enabled_assert(condition) 176 # define SDL_assert_release(condition) SDL_enabled_assert(condition) 177 # define SDL_assert_paranoid(condition) SDL_enabled_assert(condition) 178 #else 179 # error Unknown assertion level. 180 #endif 181 182 /* this assertion is never disabled at any level. */ 183 #define SDL_assert_always(condition) SDL_enabled_assert(condition) 184 185 186 typedef SDL_AssertState (SDLCALL *SDL_AssertionHandler)( 187 const SDL_AssertData* data, void* userdata); 188 189 /** 190 * \brief Set an application-defined assertion handler. 191 * 192 * This allows an app to show its own assertion UI and/or force the 193 * response to an assertion failure. If the app doesn't provide this, SDL 194 * will try to do the right thing, popping up a system-specific GUI dialog, 195 * and probably minimizing any fullscreen windows. 196 * 197 * This callback may fire from any thread, but it runs wrapped in a mutex, so 198 * it will only fire from one thread at a time. 199 * 200 * Setting the callback to NULL restores SDL's original internal handler. 201 * 202 * This callback is NOT reset to SDL's internal handler upon SDL_Quit()! 203 * 204 * \return SDL_AssertState value of how to handle the assertion failure. 205 * 206 * \param handler Callback function, called when an assertion fails. 207 * \param userdata A pointer passed to the callback as-is. 208 */ 209 extern DECLSPEC void SDLCALL SDL_SetAssertionHandler( 210 SDL_AssertionHandler handler, 211 void *userdata); 212 213 /** 214 * \brief Get the default assertion handler. 215 * 216 * This returns the function pointer that is called by default when an 217 * assertion is triggered. This is an internal function provided by SDL, 218 * that is used for assertions when SDL_SetAssertionHandler() hasn't been 219 * used to provide a different function. 220 * 221 * \return The default SDL_AssertionHandler that is called when an assert triggers. 222 */ 223 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetDefaultAssertionHandler(void); 224 225 /** 226 * \brief Get the current assertion handler. 227 * 228 * This returns the function pointer that is called when an assertion is 229 * triggered. This is either the value last passed to 230 * SDL_SetAssertionHandler(), or if no application-specified function is 231 * set, is equivalent to calling SDL_GetDefaultAssertionHandler(). 232 * 233 * \param puserdata Pointer to a void*, which will store the "userdata" 234 * pointer that was passed to SDL_SetAssertionHandler(). 235 * This value will always be NULL for the default handler. 236 * If you don't care about this data, it is safe to pass 237 * a NULL pointer to this function to ignore it. 238 * \return The SDL_AssertionHandler that is called when an assert triggers. 239 */ 240 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetAssertionHandler(void **puserdata); 241 242 /** 243 * \brief Get a list of all assertion failures. 244 * 245 * Get all assertions triggered since last call to SDL_ResetAssertionReport(), 246 * or the start of the program. 247 * 248 * The proper way to examine this data looks something like this: 249 * 250 * <code> 251 * const SDL_AssertData *item = SDL_GetAssertionReport(); 252 * while (item) { 253 * printf("'%s', %s (%s:%d), triggered %u times, always ignore: %s.\n", 254 * item->condition, item->function, item->filename, 255 * item->linenum, item->trigger_count, 256 * item->always_ignore ? "yes" : "no"); 257 * item = item->next; 258 * } 259 * </code> 260 * 261 * \return List of all assertions. 262 * \sa SDL_ResetAssertionReport 263 */ 264 extern DECLSPEC const SDL_AssertData * SDLCALL SDL_GetAssertionReport(void); 265 266 /** 267 * \brief Reset the list of all assertion failures. 268 * 269 * Reset list of all assertions triggered. 270 * 271 * \sa SDL_GetAssertionReport 272 */ 273 extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void); 274 275 276 /* these had wrong naming conventions until 2.0.4. Please update your app! */ 277 #define SDL_assert_state SDL_AssertState 278 #define SDL_assert_data SDL_AssertData 279 280 281 /* Ends C function definitions when using C++ */ 282 #ifdef __cplusplus 283 } 284 #endif 285 #include "close_code.h" 286 287 #endif /* _SDL_assert_h */ 288 289 /* vi: set ts=4 sw=4 expandtab: */ 290