include/SDL_assert.h
author Sam Lantinga <slouken@libsdl.org>
Mon, 24 Jan 2011 15:46:11 -0800
changeset 5086 c2539ff054c8
parent 5011 d306007299ac
child 5262 b530ef003506
permissions -rw-r--r--
Fixed compiling on Windows Mobile SDK 5.0 with Visual Studio 2008
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2010 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Lesser General Public
     7     License as published by the Free Software Foundation; either
     8     version 2.1 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Lesser General Public License for more details.
    14 
    15     You should have received a copy of the GNU Lesser General Public
    16     License along with this library; if not, write to the Free Software
    17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 
    23 #ifndef _SDL_assert_h
    24 #define _SDL_assert_h
    25 
    26 #include "SDL_config.h"
    27 
    28 #include "begin_code.h"
    29 /* Set up for C function definitions, even when using C++ */
    30 #ifdef __cplusplus
    31 /* *INDENT-OFF* */
    32 extern "C" {
    33 /* *INDENT-ON* */
    34 #endif
    35 
    36 #ifndef SDL_ASSERT_LEVEL
    37 #ifdef SDL_DEFAULT_ASSERT_LEVEL
    38 #define SDL_ASSERT_LEVEL SDL_DEFAULT_ASSERT_LEVEL
    39 #elif defined(_DEBUG) || defined(DEBUG) || \
    40       (defined(__GNUC__) && !defined(__OPTIMIZE__))
    41 #define SDL_ASSERT_LEVEL 2
    42 #else
    43 #define SDL_ASSERT_LEVEL 1
    44 #endif
    45 #endif /* SDL_ASSERT_LEVEL */
    46 
    47 /*
    48 These are macros and not first class functions so that the debugger breaks
    49 on the assertion line and not in some random guts of SDL, and so each
    50 assert can have unique static variables associated with it.
    51 */
    52 
    53 #if defined(_MSC_VER) && !defined(_WIN32_WCE)
    54 #include <intrin.h>
    55     #define SDL_TriggerBreakpoint() __debugbreak()
    56 #elif (defined(__GNUC__) && ((__i386__) || (__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 (__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 #if (SDL_ASSERT_LEVEL > 0)
    95 
    96 typedef enum
    97 {
    98     SDL_ASSERTION_RETRY,  /**< Retry the assert immediately. */
    99     SDL_ASSERTION_BREAK,  /**< Make the debugger trigger a breakpoint. */
   100     SDL_ASSERTION_ABORT,  /**< Terminate the program. */
   101     SDL_ASSERTION_IGNORE,  /**< Ignore the assert. */
   102     SDL_ASSERTION_ALWAYS_IGNORE,  /**< Ignore the assert from now on. */
   103 } SDL_assert_state;
   104 
   105 typedef struct SDL_assert_data
   106 {
   107     int always_ignore;
   108     unsigned int trigger_count;
   109     const char *condition;
   110     const char *filename;
   111     int linenum;
   112     const char *function;
   113     const struct SDL_assert_data *next;
   114 } SDL_assert_data;
   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 *, 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->condition) {
   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. This never returns NULL,
   218  *          even if there are no items.
   219  *  \sa SDL_ResetAssertionReport
   220  */
   221 extern DECLSPEC const SDL_assert_data * SDLCALL SDL_GetAssertionReport(void);
   222 
   223 /**
   224  *  \brief Reset the list of all assertion failures.
   225  *
   226  *  Reset list of all assertions triggered.
   227  *
   228  *  \sa SDL_GetAssertionReport
   229  */
   230 extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void);
   231 
   232 /* Ends C function definitions when using C++ */
   233 #ifdef __cplusplus
   234 /* *INDENT-OFF* */
   235 }
   236 /* *INDENT-ON* */
   237 #endif
   238 #include "close_code.h"
   239 
   240 #endif /* _SDL_assert_h */
   241 
   242 /* vi: set ts=4 sw=4 expandtab: */