include/SDL_assert.h
author Manuel Alfayate Corchete <redwindwanderer@gmail.com>
Mon, 03 Aug 2020 22:24:49 +0200
changeset 13974 c47a91919b1e
parent 13952 5647279e5c91
permissions -rw-r--r--
kmsdrm: update SwapWindow fn, moving it to triple-buffer.
     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(__APPLE__) && defined(__arm64__) )  /* this might work on other ARM targets, but this is a known quantity... */
    57     #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "brk #22\n\t" )
    58 #elif defined(__386__) && defined(__WATCOMC__)
    59     #define SDL_TriggerBreakpoint() { _asm { int 0x03 } }
    60 #elif defined(HAVE_SIGNAL_H) && !defined(__WATCOMC__)
    61     #include <signal.h>
    62     #define SDL_TriggerBreakpoint() raise(SIGTRAP)
    63 #else
    64     /* How do we trigger breakpoints on this platform? */
    65     #define SDL_TriggerBreakpoint()
    66 #endif
    67 
    68 #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 supports __func__ as a standard. */
    69 #   define SDL_FUNCTION __func__
    70 #elif ((__GNUC__ >= 2) || defined(_MSC_VER) || defined (__WATCOMC__))
    71 #   define SDL_FUNCTION __FUNCTION__
    72 #else
    73 #   define SDL_FUNCTION "???"
    74 #endif
    75 #define SDL_FILE    __FILE__
    76 #define SDL_LINE    __LINE__
    77 
    78 /*
    79 sizeof (x) makes the compiler still parse the expression even without
    80 assertions enabled, so the code is always checked at compile time, but
    81 doesn't actually generate code for it, so there are no side effects or
    82 expensive checks at run time, just the constant size of what x WOULD be,
    83 which presumably gets optimized out as unused.
    84 This also solves the problem of...
    85 
    86     int somevalue = blah();
    87     SDL_assert(somevalue == 1);
    88 
    89 ...which would cause compiles to complain that somevalue is unused if we
    90 disable assertions.
    91 */
    92 
    93 /* "while (0,0)" fools Microsoft's compiler's /W4 warning level into thinking
    94     this condition isn't constant. And looks like an owl's face! */
    95 #ifdef _MSC_VER  /* stupid /W4 warnings. */
    96 #define SDL_NULL_WHILE_LOOP_CONDITION (0,0)
    97 #else
    98 #define SDL_NULL_WHILE_LOOP_CONDITION (0)
    99 #endif
   100 
   101 #define SDL_disabled_assert(condition) \
   102     do { (void) sizeof ((condition)); } while (SDL_NULL_WHILE_LOOP_CONDITION)
   103 
   104 typedef enum
   105 {
   106     SDL_ASSERTION_RETRY,  /**< Retry the assert immediately. */
   107     SDL_ASSERTION_BREAK,  /**< Make the debugger trigger a breakpoint. */
   108     SDL_ASSERTION_ABORT,  /**< Terminate the program. */
   109     SDL_ASSERTION_IGNORE,  /**< Ignore the assert. */
   110     SDL_ASSERTION_ALWAYS_IGNORE  /**< Ignore the assert from now on. */
   111 } SDL_AssertState;
   112 
   113 typedef struct SDL_AssertData
   114 {
   115     int always_ignore;
   116     unsigned int trigger_count;
   117     const char *condition;
   118     const char *filename;
   119     int linenum;
   120     const char *function;
   121     const struct SDL_AssertData *next;
   122 } SDL_AssertData;
   123 
   124 #if (SDL_ASSERT_LEVEL > 0)
   125 
   126 /* Never call this directly. Use the SDL_assert* macros. */
   127 extern DECLSPEC SDL_AssertState SDLCALL SDL_ReportAssertion(SDL_AssertData *,
   128                                                              const char *,
   129                                                              const char *, int)
   130 #if defined(__clang__)
   131 #if __has_feature(attribute_analyzer_noreturn)
   132 /* this tells Clang's static analysis that we're a custom assert function,
   133    and that the analyzer should assume the condition was always true past this
   134    SDL_assert test. */
   135    __attribute__((analyzer_noreturn))
   136 #endif
   137 #endif
   138 ;
   139 
   140 /* the do {} while(0) avoids dangling else problems:
   141     if (x) SDL_assert(y); else blah();
   142        ... without the do/while, the "else" could attach to this macro's "if".
   143    We try to handle just the minimum we need here in a macro...the loop,
   144    the static vars, and break points. The heavy lifting is handled in
   145    SDL_ReportAssertion(), in SDL_assert.c.
   146 */
   147 #define SDL_enabled_assert(condition) \
   148     do { \
   149         while ( !(condition) ) { \
   150             static struct SDL_AssertData sdl_assert_data = { \
   151                 0, 0, #condition, 0, 0, 0, 0 \
   152             }; \
   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 #endif  /* enabled assertions support code */
   164 
   165 /* Enable various levels of assertions. */
   166 #if SDL_ASSERT_LEVEL == 0   /* assertions disabled */
   167 #   define SDL_assert(condition) SDL_disabled_assert(condition)
   168 #   define SDL_assert_release(condition) SDL_disabled_assert(condition)
   169 #   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
   170 #elif SDL_ASSERT_LEVEL == 1  /* release settings. */
   171 #   define SDL_assert(condition) SDL_disabled_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 == 2  /* normal 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_disabled_assert(condition)
   178 #elif SDL_ASSERT_LEVEL == 3  /* paranoid settings. */
   179 #   define SDL_assert(condition) SDL_enabled_assert(condition)
   180 #   define SDL_assert_release(condition) SDL_enabled_assert(condition)
   181 #   define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
   182 #else
   183 #   error Unknown assertion level.
   184 #endif
   185 
   186 /* this assertion is never disabled at any level. */
   187 #define SDL_assert_always(condition) SDL_enabled_assert(condition)
   188 
   189 
   190 typedef SDL_AssertState (SDLCALL *SDL_AssertionHandler)(
   191                                  const SDL_AssertData* data, void* userdata);
   192 
   193 /**
   194  *  \brief Set an application-defined assertion handler.
   195  *
   196  *  This allows an app to show its own assertion UI and/or force the
   197  *  response to an assertion failure. If the app doesn't provide this, SDL
   198  *  will try to do the right thing, popping up a system-specific GUI dialog,
   199  *  and probably minimizing any fullscreen windows.
   200  *
   201  *  This callback may fire from any thread, but it runs wrapped in a mutex, so
   202  *  it will only fire from one thread at a time.
   203  *
   204  *  Setting the callback to NULL restores SDL's original internal handler.
   205  *
   206  *  This callback is NOT reset to SDL's internal handler upon SDL_Quit()!
   207  *
   208  *  Return SDL_AssertState value of how to handle the assertion failure.
   209  *
   210  *  \param handler Callback function, called when an assertion fails.
   211  *  \param userdata A pointer passed to the callback as-is.
   212  */
   213 extern DECLSPEC void SDLCALL SDL_SetAssertionHandler(
   214                                             SDL_AssertionHandler handler,
   215                                             void *userdata);
   216 
   217 /**
   218  *  \brief Get the default assertion handler.
   219  *
   220  *  This returns the function pointer that is called by default when an
   221  *   assertion is triggered. This is an internal function provided by SDL,
   222  *   that is used for assertions when SDL_SetAssertionHandler() hasn't been
   223  *   used to provide a different function.
   224  *
   225  *  \return The default SDL_AssertionHandler that is called when an assert triggers.
   226  */
   227 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetDefaultAssertionHandler(void);
   228 
   229 /**
   230  *  \brief Get the current assertion handler.
   231  *
   232  *  This returns the function pointer that is called when an assertion is
   233  *   triggered. This is either the value last passed to
   234  *   SDL_SetAssertionHandler(), or if no application-specified function is
   235  *   set, is equivalent to calling SDL_GetDefaultAssertionHandler().
   236  *
   237  *   \param puserdata Pointer to a void*, which will store the "userdata"
   238  *                    pointer that was passed to SDL_SetAssertionHandler().
   239  *                    This value will always be NULL for the default handler.
   240  *                    If you don't care about this data, it is safe to pass
   241  *                    a NULL pointer to this function to ignore it.
   242  *  \return The SDL_AssertionHandler that is called when an assert triggers.
   243  */
   244 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetAssertionHandler(void **puserdata);
   245 
   246 /**
   247  *  \brief Get a list of all assertion failures.
   248  *
   249  *  Get all assertions triggered since last call to SDL_ResetAssertionReport(),
   250  *  or the start of the program.
   251  *
   252  *  The proper way to examine this data looks something like this:
   253  *
   254  *  <code>
   255  *  const SDL_AssertData *item = SDL_GetAssertionReport();
   256  *  while (item) {
   257  *      printf("'%s', %s (%s:%d), triggered %u times, always ignore: %s.\\n",
   258  *             item->condition, item->function, item->filename,
   259  *             item->linenum, item->trigger_count,
   260  *             item->always_ignore ? "yes" : "no");
   261  *      item = item->next;
   262  *  }
   263  *  </code>
   264  *
   265  *  \return List of all assertions.
   266  *  \sa SDL_ResetAssertionReport
   267  */
   268 extern DECLSPEC const SDL_AssertData * SDLCALL SDL_GetAssertionReport(void);
   269 
   270 /**
   271  *  \brief Reset the list of all assertion failures.
   272  *
   273  *  Reset list of all assertions triggered.
   274  *
   275  *  \sa SDL_GetAssertionReport
   276  */
   277 extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void);
   278 
   279 
   280 /* these had wrong naming conventions until 2.0.4. Please update your app! */
   281 #define SDL_assert_state SDL_AssertState
   282 #define SDL_assert_data SDL_AssertData
   283 
   284 
   285 /* Ends C function definitions when using C++ */
   286 #ifdef __cplusplus
   287 }
   288 #endif
   289 #include "close_code.h"
   290 
   291 #endif /* SDL_assert_h_ */
   292 
   293 /* vi: set ts=4 sw=4 expandtab: */