include/SDL_assert.h
author Ryan C. Gordon <icculus@icculus.org>
Fri, 20 Mar 2015 21:57:15 -0400
changeset 9414 669bf9fb901e
parent 9371 375799828431
child 9463 d5925549bfe0
permissions -rw-r--r--
Several corrections to the CMake project files (thanks, Ozkan!).

Fixes Bugzilla #2732.
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2014 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 #ifdef _MSC_VER  /* stupid /W4 warnings. */
    90 #define SDL_NULL_WHILE_LOOP_CONDITION (-1 == __LINE__)
    91 #else
    92 #define SDL_NULL_WHILE_LOOP_CONDITION (0)
    93 #endif
    94 
    95 #define SDL_disabled_assert(condition) \
    96     do { (void) sizeof ((condition)); } while (SDL_NULL_WHILE_LOOP_CONDITION)
    97 
    98 typedef enum
    99 {
   100     SDL_ASSERTION_RETRY,  /**< Retry the assert immediately. */
   101     SDL_ASSERTION_BREAK,  /**< Make the debugger trigger a breakpoint. */
   102     SDL_ASSERTION_ABORT,  /**< Terminate the program. */
   103     SDL_ASSERTION_IGNORE,  /**< Ignore the assert. */
   104     SDL_ASSERTION_ALWAYS_IGNORE  /**< Ignore the assert from now on. */
   105 } SDL_AssertState;
   106 
   107 typedef struct SDL_AssertData
   108 {
   109     int always_ignore;
   110     unsigned int trigger_count;
   111     const char *condition;
   112     const char *filename;
   113     int linenum;
   114     const char *function;
   115     const struct SDL_AssertData *next;
   116 } SDL_AssertData;
   117 
   118 #if (SDL_ASSERT_LEVEL > 0)
   119 
   120 /* Never call this directly. Use the SDL_assert* macros. */
   121 extern DECLSPEC SDL_AssertState SDLCALL SDL_ReportAssertion(SDL_AssertData *,
   122                                                              const char *,
   123                                                              const char *, int)
   124 #if defined(__clang__)
   125 #if __has_feature(attribute_analyzer_noreturn)
   126 /* this tells Clang's static analysis that we're a custom assert function,
   127    and that the analyzer should assume the condition was always true past this
   128    SDL_assert test. */
   129    __attribute__((analyzer_noreturn))
   130 #endif
   131 #endif
   132 ;
   133 
   134 /* the do {} while(0) avoids dangling else problems:
   135     if (x) SDL_assert(y); else blah();
   136        ... without the do/while, the "else" could attach to this macro's "if".
   137    We try to handle just the minimum we need here in a macro...the loop,
   138    the static vars, and break points. The heavy lifting is handled in
   139    SDL_ReportAssertion(), in SDL_assert.c.
   140 */
   141 #define SDL_enabled_assert(condition) \
   142     do { \
   143         while ( !(condition) ) { \
   144             static struct SDL_AssertData sdl_assert_data = { \
   145                 0, 0, #condition, 0, 0, 0, 0 \
   146             }; \
   147             const SDL_AssertState sdl_assert_state = SDL_ReportAssertion(&sdl_assert_data, SDL_FUNCTION, SDL_FILE, SDL_LINE); \
   148             if (sdl_assert_state == SDL_ASSERTION_RETRY) { \
   149                 continue; /* go again. */ \
   150             } else if (sdl_assert_state == SDL_ASSERTION_BREAK) { \
   151                 SDL_TriggerBreakpoint(); \
   152             } \
   153             break; /* not retrying. */ \
   154         } \
   155     } while (SDL_NULL_WHILE_LOOP_CONDITION)
   156 
   157 #endif  /* enabled assertions support code */
   158 
   159 /* Enable various levels of assertions. */
   160 #if SDL_ASSERT_LEVEL == 0   /* assertions disabled */
   161 #   define SDL_assert(condition) SDL_disabled_assert(condition)
   162 #   define SDL_assert_release(condition) SDL_disabled_assert(condition)
   163 #   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
   164 #elif SDL_ASSERT_LEVEL == 1  /* release settings. */
   165 #   define SDL_assert(condition) SDL_disabled_assert(condition)
   166 #   define SDL_assert_release(condition) SDL_enabled_assert(condition)
   167 #   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
   168 #elif SDL_ASSERT_LEVEL == 2  /* normal settings. */
   169 #   define SDL_assert(condition) SDL_enabled_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 == 3  /* paranoid 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_enabled_assert(condition)
   176 #else
   177 #   error Unknown assertion level.
   178 #endif
   179 
   180 /* this assertion is never disabled at any level. */
   181 #define SDL_assert_always(condition) SDL_enabled_assert(condition)
   182 
   183 
   184 typedef SDL_AssertState (SDLCALL *SDL_AssertionHandler)(
   185                                  const SDL_AssertData* data, void* userdata);
   186 
   187 /**
   188  *  \brief Set an application-defined assertion handler.
   189  *
   190  *  This allows an app to show its own assertion UI and/or force the
   191  *  response to an assertion failure. If the app doesn't provide this, SDL
   192  *  will try to do the right thing, popping up a system-specific GUI dialog,
   193  *  and probably minimizing any fullscreen windows.
   194  *
   195  *  This callback may fire from any thread, but it runs wrapped in a mutex, so
   196  *  it will only fire from one thread at a time.
   197  *
   198  *  Setting the callback to NULL restores SDL's original internal handler.
   199  *
   200  *  This callback is NOT reset to SDL's internal handler upon SDL_Quit()!
   201  *
   202  *  \return SDL_AssertState value of how to handle the assertion failure.
   203  *
   204  *  \param handler Callback function, called when an assertion fails.
   205  *  \param userdata A pointer passed to the callback as-is.
   206  */
   207 extern DECLSPEC void SDLCALL SDL_SetAssertionHandler(
   208                                             SDL_AssertionHandler handler,
   209                                             void *userdata);
   210 
   211 /**
   212  *  \brief Get the default assertion handler.
   213  *
   214  *  This returns the function pointer that is called by default when an
   215  *   assertion is triggered. This is an internal function provided by SDL,
   216  *   that is used for assertions when SDL_SetAssertionHandler() hasn't been
   217  *   used to provide a different function.
   218  *
   219  *  \return The default SDL_AssertionHandler that is called when an assert triggers.
   220  */
   221 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetDefaultAssertionHandler(void);
   222 
   223 /**
   224  *  \brief Get the current assertion handler.
   225  *
   226  *  This returns the function pointer that is called when an assertion is
   227  *   triggered. This is either the value last passed to
   228  *   SDL_SetAssertionHandler(), or if no application-specified function is
   229  *   set, is equivalent to calling SDL_GetDefaultAssertionHandler().
   230  *
   231  *   \param puserdata Pointer to a void*, which will store the "userdata"
   232  *                    pointer that was passed to SDL_SetAssertionHandler().
   233  *                    This value will always be NULL for the default handler.
   234  *                    If you don't care about this data, it is safe to pass
   235  *                    a NULL pointer to this function to ignore it.
   236  *  \return The SDL_AssertionHandler that is called when an assert triggers.
   237  */
   238 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetAssertionHandler(void **puserdata);
   239 
   240 /**
   241  *  \brief Get a list of all assertion failures.
   242  *
   243  *  Get all assertions triggered since last call to SDL_ResetAssertionReport(),
   244  *  or the start of the program.
   245  *
   246  *  The proper way to examine this data looks something like this:
   247  *
   248  *  <code>
   249  *  const SDL_AssertData *item = SDL_GetAssertionReport();
   250  *  while (item) {
   251  *      printf("'%s', %s (%s:%d), triggered %u times, always ignore: %s.\n",
   252  *             item->condition, item->function, item->filename,
   253  *             item->linenum, item->trigger_count,
   254  *             item->always_ignore ? "yes" : "no");
   255  *      item = item->next;
   256  *  }
   257  *  </code>
   258  *
   259  *  \return List of all assertions.
   260  *  \sa SDL_ResetAssertionReport
   261  */
   262 extern DECLSPEC const SDL_AssertData * SDLCALL SDL_GetAssertionReport(void);
   263 
   264 /**
   265  *  \brief Reset the list of all assertion failures.
   266  *
   267  *  Reset list of all assertions triggered.
   268  *
   269  *  \sa SDL_GetAssertionReport
   270  */
   271 extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void);
   272 
   273 
   274 /* these had wrong naming conventions until 2.0.4. Please update your app! */
   275 #define SDL_assert_state SDL_AssertState
   276 #define SDL_assert_data SDL_AssertData
   277 
   278 
   279 /* Ends C function definitions when using C++ */
   280 #ifdef __cplusplus
   281 }
   282 #endif
   283 #include "close_code.h"
   284 
   285 #endif /* _SDL_assert_h */
   286 
   287 /* vi: set ts=4 sw=4 expandtab: */