include/SDL_assert.h
author Sam Lantinga <slouken@libsdl.org>
Sun, 02 Feb 2014 00:53:27 -0800
changeset 8149 681eb46b8ac4
parent 7736 84d89d60908f
child 8167 82ec2a95e664
permissions -rw-r--r--
Fixed bug 2374 - Update copyright for 2014...

Is it that time already??
     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(__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_assert_state;
   106 
   107 typedef struct SDL_assert_data
   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_assert_data *next;
   116 } SDL_assert_data;
   117 
   118 #if (SDL_ASSERT_LEVEL > 0)
   119 
   120 /* Never call this directly. Use the SDL_assert* macros. */
   121 extern DECLSPEC SDL_assert_state SDLCALL SDL_ReportAssertion(SDL_assert_data *,
   122                                                              const char *,
   123                                                              const char *, int);
   124 
   125 /* the do {} while(0) avoids dangling else problems:
   126     if (x) SDL_assert(y); else blah();
   127        ... without the do/while, the "else" could attach to this macro's "if".
   128    We try to handle just the minimum we need here in a macro...the loop,
   129    the static vars, and break points. The heavy lifting is handled in
   130    SDL_ReportAssertion(), in SDL_assert.c.
   131 */
   132 #define SDL_enabled_assert(condition) \
   133     do { \
   134         while ( !(condition) ) { \
   135             static struct SDL_assert_data assert_data = { \
   136                 0, 0, #condition, 0, 0, 0, 0 \
   137             }; \
   138             const SDL_assert_state state = SDL_ReportAssertion(&assert_data, \
   139                                                                SDL_FUNCTION, \
   140                                                                SDL_FILE, \
   141                                                                SDL_LINE); \
   142             if (state == SDL_ASSERTION_RETRY) { \
   143                 continue; /* go again. */ \
   144             } else if (state == SDL_ASSERTION_BREAK) { \
   145                 SDL_TriggerBreakpoint(); \
   146             } \
   147             break; /* not retrying. */ \
   148         } \
   149     } while (SDL_NULL_WHILE_LOOP_CONDITION)
   150 
   151 #endif  /* enabled assertions support code */
   152 
   153 /* Enable various levels of assertions. */
   154 #if SDL_ASSERT_LEVEL == 0   /* assertions disabled */
   155 #   define SDL_assert(condition) SDL_disabled_assert(condition)
   156 #   define SDL_assert_release(condition) SDL_disabled_assert(condition)
   157 #   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
   158 #elif SDL_ASSERT_LEVEL == 1  /* release settings. */
   159 #   define SDL_assert(condition) SDL_disabled_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 == 2  /* normal 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_disabled_assert(condition)
   166 #elif SDL_ASSERT_LEVEL == 3  /* paranoid settings. */
   167 #   define SDL_assert(condition) SDL_enabled_assert(condition)
   168 #   define SDL_assert_release(condition) SDL_enabled_assert(condition)
   169 #   define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
   170 #else
   171 #   error Unknown assertion level.
   172 #endif
   173 
   174 /* this assertion is never disabled at any level. */
   175 #define SDL_assert_always(condition) SDL_enabled_assert(condition)
   176 
   177 
   178 typedef SDL_assert_state (SDLCALL *SDL_AssertionHandler)(
   179                                  const SDL_assert_data* data, void* userdata);
   180 
   181 /**
   182  *  \brief Set an application-defined assertion handler.
   183  *
   184  *  This allows an app to show its own assertion UI and/or force the
   185  *  response to an assertion failure. If the app doesn't provide this, SDL
   186  *  will try to do the right thing, popping up a system-specific GUI dialog,
   187  *  and probably minimizing any fullscreen windows.
   188  *
   189  *  This callback may fire from any thread, but it runs wrapped in a mutex, so
   190  *  it will only fire from one thread at a time.
   191  *
   192  *  Setting the callback to NULL restores SDL's original internal handler.
   193  *
   194  *  This callback is NOT reset to SDL's internal handler upon SDL_Quit()!
   195  *
   196  *  \return SDL_assert_state value of how to handle the assertion failure.
   197  *
   198  *  \param handler Callback function, called when an assertion fails.
   199  *  \param userdata A pointer passed to the callback as-is.
   200  */
   201 extern DECLSPEC void SDLCALL SDL_SetAssertionHandler(
   202                                             SDL_AssertionHandler handler,
   203                                             void *userdata);
   204 
   205 /**
   206  *  \brief Get a list of all assertion failures.
   207  *
   208  *  Get all assertions triggered since last call to SDL_ResetAssertionReport(),
   209  *  or the start of the program.
   210  *
   211  *  The proper way to examine this data looks something like this:
   212  *
   213  *  <code>
   214  *  const SDL_assert_data *item = SDL_GetAssertionReport();
   215  *  while (item) {
   216  *      printf("'%s', %s (%s:%d), triggered %u times, always ignore: %s.\n",
   217  *             item->condition, item->function, item->filename,
   218  *             item->linenum, item->trigger_count,
   219  *             item->always_ignore ? "yes" : "no");
   220  *      item = item->next;
   221  *  }
   222  *  </code>
   223  *
   224  *  \return List of all assertions.
   225  *  \sa SDL_ResetAssertionReport
   226  */
   227 extern DECLSPEC const SDL_assert_data * SDLCALL SDL_GetAssertionReport(void);
   228 
   229 /**
   230  *  \brief Reset the list of all assertion failures.
   231  *
   232  *  Reset list of all assertions triggered.
   233  *
   234  *  \sa SDL_GetAssertionReport
   235  */
   236 extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void);
   237 
   238 /* Ends C function definitions when using C++ */
   239 #ifdef __cplusplus
   240 }
   241 #endif
   242 #include "close_code.h"
   243 
   244 #endif /* _SDL_assert_h */
   245 
   246 /* vi: set ts=4 sw=4 expandtab: */