include/SDL_assert.h
author Sam Lantinga <slouken@libsdl.org>
Sat, 18 May 2013 12:48:50 -0700
changeset 7190 11612d544fcd
parent 6885 700f1b25f77f
child 7191 75360622e65f
permissions -rw-r--r--
Added mobile application events, with implementations for iOS and Android
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2013 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 /* *INDENT-OFF* */
    31 extern "C" {
    32 /* *INDENT-ON* */
    33 #endif
    34 
    35 #ifndef SDL_ASSERT_LEVEL
    36 #ifdef SDL_DEFAULT_ASSERT_LEVEL
    37 #define SDL_ASSERT_LEVEL SDL_DEFAULT_ASSERT_LEVEL
    38 #elif defined(_DEBUG) || defined(DEBUG) || \
    39       (defined(__GNUC__) && !defined(__OPTIMIZE__))
    40 #define SDL_ASSERT_LEVEL 2
    41 #else
    42 #define SDL_ASSERT_LEVEL 1
    43 #endif
    44 #endif /* SDL_ASSERT_LEVEL */
    45 
    46 /*
    47 These are macros and not first class functions so that the debugger breaks
    48 on the assertion line and not in some random guts of SDL, and so each
    49 assert can have unique static variables associated with it.
    50 */
    51 
    52 #if defined(_MSC_VER)
    53 /* Don't include intrin.h here because it contains C++ code */
    54     extern void __cdecl __debugbreak(void);
    55     #define SDL_TriggerBreakpoint() __debugbreak()
    56 #elif (defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)))
    57     #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "int $3\n\t" )
    58 #elif defined(HAVE_SIGNAL_H)
    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))
    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 #define SDL_disabled_assert(condition) \
    92     do { (void) sizeof ((condition)); } while (0)
    93 
    94 typedef enum
    95 {
    96     SDL_ASSERTION_RETRY,  /**< Retry the assert immediately. */
    97     SDL_ASSERTION_BREAK,  /**< Make the debugger trigger a breakpoint. */
    98     SDL_ASSERTION_ABORT,  /**< Terminate the program. */
    99     SDL_ASSERTION_IGNORE,  /**< Ignore the assert. */
   100     SDL_ASSERTION_ALWAYS_IGNORE  /**< Ignore the assert from now on. */
   101 } SDL_assert_state;
   102 
   103 typedef struct SDL_assert_data
   104 {
   105     int always_ignore;
   106     unsigned int trigger_count;
   107     const char *condition;
   108     const char *filename;
   109     int linenum;
   110     const char *function;
   111     const struct SDL_assert_data *next;
   112 } SDL_assert_data;
   113 
   114 #if (SDL_ASSERT_LEVEL > 0)
   115 
   116 /* Never call this directly. Use the SDL_assert* macros. */
   117 extern DECLSPEC SDL_assert_state SDLCALL SDL_ReportAssertion(SDL_assert_data *,
   118                                                              const char *,
   119                                                              const char *, int);
   120 
   121 /* the do {} while(0) avoids dangling else problems:
   122     if (x) SDL_assert(y); else blah();
   123        ... without the do/while, the "else" could attach to this macro's "if".
   124    We try to handle just the minimum we need here in a macro...the loop,
   125    the static vars, and break points. The heavy lifting is handled in
   126    SDL_ReportAssertion(), in SDL_assert.c.
   127 */
   128 #define SDL_enabled_assert(condition) \
   129     do { \
   130         while ( !(condition) ) { \
   131             static struct SDL_assert_data assert_data = { \
   132                 0, 0, #condition, 0, 0, 0, 0 \
   133             }; \
   134             const SDL_assert_state state = SDL_ReportAssertion(&assert_data, \
   135                                                                SDL_FUNCTION, \
   136                                                                SDL_FILE, \
   137                                                                SDL_LINE); \
   138             if (state == SDL_ASSERTION_RETRY) { \
   139                 continue; /* go again. */ \
   140             } else if (state == SDL_ASSERTION_BREAK) { \
   141                 SDL_TriggerBreakpoint(); \
   142             } \
   143             break; /* not retrying. */ \
   144         } \
   145     } while (0)
   146 
   147 #endif  /* enabled assertions support code */
   148 
   149 /* Enable various levels of assertions. */
   150 #if SDL_ASSERT_LEVEL == 0   /* assertions disabled */
   151 #   define SDL_assert(condition) SDL_disabled_assert(condition)
   152 #   define SDL_assert_release(condition) SDL_disabled_assert(condition)
   153 #   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
   154 #elif SDL_ASSERT_LEVEL == 1  /* release settings. */
   155 #   define SDL_assert(condition) SDL_disabled_assert(condition)
   156 #   define SDL_assert_release(condition) SDL_enabled_assert(condition)
   157 #   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
   158 #elif SDL_ASSERT_LEVEL == 2  /* normal settings. */
   159 #   define SDL_assert(condition) SDL_enabled_assert(condition)
   160 #   define SDL_assert_release(condition) SDL_enabled_assert(condition)
   161 #   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
   162 #elif SDL_ASSERT_LEVEL == 3  /* paranoid settings. */
   163 #   define SDL_assert(condition) SDL_enabled_assert(condition)
   164 #   define SDL_assert_release(condition) SDL_enabled_assert(condition)
   165 #   define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
   166 #else
   167 #   error Unknown assertion level.
   168 #endif
   169 
   170 
   171 typedef SDL_assert_state (SDLCALL *SDL_AssertionHandler)(
   172                                  const SDL_assert_data* data, void* userdata);
   173 
   174 /**
   175  *  \brief Set an application-defined assertion handler.
   176  *
   177  *  This allows an app to show its own assertion UI and/or force the
   178  *  response to an assertion failure. If the app doesn't provide this, SDL
   179  *  will try to do the right thing, popping up a system-specific GUI dialog,
   180  *  and probably minimizing any fullscreen windows.
   181  *
   182  *  This callback may fire from any thread, but it runs wrapped in a mutex, so
   183  *  it will only fire from one thread at a time.
   184  *
   185  *  Setting the callback to NULL restores SDL's original internal handler.
   186  *
   187  *  This callback is NOT reset to SDL's internal handler upon SDL_Quit()!
   188  *
   189  *  \return SDL_assert_state value of how to handle the assertion failure.
   190  *  
   191  *  \param handler Callback function, called when an assertion fails.
   192  *  \param userdata A pointer passed to the callback as-is.
   193  */
   194 extern DECLSPEC void SDLCALL SDL_SetAssertionHandler(
   195                                             SDL_AssertionHandler handler,
   196                                             void *userdata);
   197 
   198 /**
   199  *  \brief Get a list of all assertion failures.
   200  *
   201  *  Get all assertions triggered since last call to SDL_ResetAssertionReport(),
   202  *  or the start of the program.
   203  *
   204  *  The proper way to examine this data looks something like this:
   205  *
   206  *  <code>
   207  *  const SDL_assert_data *item = SDL_GetAssertionReport();
   208  *  while (item) {
   209  *      printf("'%s', %s (%s:%d), triggered %u times, always ignore: %s.\n",
   210  *             item->condition, item->function, item->filename,
   211  *             item->linenum, item->trigger_count,
   212  *             item->always_ignore ? "yes" : "no");
   213  *      item = item->next;
   214  *  }
   215  *  </code>
   216  *
   217  *  \return List of all assertions.
   218  *  \sa SDL_ResetAssertionReport
   219  */
   220 extern DECLSPEC const SDL_assert_data * SDLCALL SDL_GetAssertionReport(void);
   221 
   222 /**
   223  *  \brief Reset the list of all assertion failures.
   224  *
   225  *  Reset list of all assertions triggered.
   226  *
   227  *  \sa SDL_GetAssertionReport
   228  */
   229 extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void);
   230 
   231 /* Ends C function definitions when using C++ */
   232 #ifdef __cplusplus
   233 /* *INDENT-OFF* */
   234 }
   235 /* *INDENT-ON* */
   236 #endif
   237 #include "close_code.h"
   238 
   239 #endif /* _SDL_assert_h */
   240 
   241 /* vi: set ts=4 sw=4 expandtab: */