include/SDL_assert.h
author Sam Lantinga <slouken@libsdl.org>
Tue, 15 Mar 2011 19:37:38 -0700
changeset 5491 abdd970a65a8
parent 5262 b530ef003506
child 5535 96594ac5fd1a
permissions -rw-r--r--
Fixed error because intrin.h contains C++ code and can't be included in an extern "C" block.
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2011 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 /* Don't include intrin.h here because it contains C++ code */
    55 extern void __cdecl __debugbreak(void);
    56     #define SDL_TriggerBreakpoint() __debugbreak()
    57 #elif (defined(__GNUC__) && ((__i386__) || (__x86_64__)))
    58     #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "int $3\n\t" )
    59 #elif defined(HAVE_SIGNAL_H)
    60     #include <signal.h>
    61     #define SDL_TriggerBreakpoint() raise(SIGTRAP)
    62 #else
    63     /* How do we trigger breakpoints on this platform? */
    64     #define SDL_TriggerBreakpoint()
    65 #endif
    66 
    67 #if (__STDC_VERSION__ >= 199901L) /* C99 supports __func__ as a standard. */
    68 #   define SDL_FUNCTION __func__
    69 #elif ((__GNUC__ >= 2) || defined(_MSC_VER))
    70 #   define SDL_FUNCTION __FUNCTION__
    71 #else
    72 #   define SDL_FUNCTION "???"
    73 #endif
    74 #define SDL_FILE    __FILE__
    75 #define SDL_LINE    __LINE__
    76 
    77 /*
    78 sizeof (x) makes the compiler still parse the expression even without
    79 assertions enabled, so the code is always checked at compile time, but
    80 doesn't actually generate code for it, so there are no side effects or
    81 expensive checks at run time, just the constant size of what x WOULD be,
    82 which presumably gets optimized out as unused.
    83 This also solves the problem of...
    84 
    85     int somevalue = blah();
    86     SDL_assert(somevalue == 1);
    87 
    88 ...which would cause compiles to complain that somevalue is unused if we
    89 disable assertions.
    90 */
    91 
    92 #define SDL_disabled_assert(condition) \
    93     do { (void) sizeof ((condition)); } while (0)
    94 
    95 #if (SDL_ASSERT_LEVEL > 0)
    96 
    97 typedef enum
    98 {
    99     SDL_ASSERTION_RETRY,  /**< Retry the assert immediately. */
   100     SDL_ASSERTION_BREAK,  /**< Make the debugger trigger a breakpoint. */
   101     SDL_ASSERTION_ABORT,  /**< Terminate the program. */
   102     SDL_ASSERTION_IGNORE,  /**< Ignore the assert. */
   103     SDL_ASSERTION_ALWAYS_IGNORE,  /**< Ignore the assert from now on. */
   104 } SDL_assert_state;
   105 
   106 typedef struct SDL_assert_data
   107 {
   108     int always_ignore;
   109     unsigned int trigger_count;
   110     const char *condition;
   111     const char *filename;
   112     int linenum;
   113     const char *function;
   114     const struct SDL_assert_data *next;
   115 } SDL_assert_data;
   116 
   117 /* Never call this directly. Use the SDL_assert* macros. */
   118 extern DECLSPEC SDL_assert_state SDLCALL SDL_ReportAssertion(SDL_assert_data *,
   119                                                              const char *,
   120                                                              const char *, int);
   121 
   122 /* the do {} while(0) avoids dangling else problems:
   123     if (x) SDL_assert(y); else blah();
   124        ... without the do/while, the "else" could attach to this macro's "if".
   125    We try to handle just the minimum we need here in a macro...the loop,
   126    the static vars, and break points. The heavy lifting is handled in
   127    SDL_ReportAssertion(), in SDL_assert.c.
   128 */
   129 #define SDL_enabled_assert(condition) \
   130     do { \
   131         while ( !(condition) ) { \
   132             static struct SDL_assert_data assert_data = { \
   133                 0, 0, #condition, 0, 0, 0, 0 \
   134             }; \
   135             const SDL_assert_state state = SDL_ReportAssertion(&assert_data, \
   136                                                                SDL_FUNCTION, \
   137                                                                SDL_FILE, \
   138                                                                SDL_LINE); \
   139             if (state == SDL_ASSERTION_RETRY) { \
   140                 continue; /* go again. */ \
   141             } else if (state == SDL_ASSERTION_BREAK) { \
   142                 SDL_TriggerBreakpoint(); \
   143             } \
   144             break; /* not retrying. */ \
   145         } \
   146     } while (0)
   147 
   148 #endif  /* enabled assertions support code */
   149 
   150 /* Enable various levels of assertions. */
   151 #if SDL_ASSERT_LEVEL == 0   /* assertions disabled */
   152 #   define SDL_assert(condition) SDL_disabled_assert(condition)
   153 #   define SDL_assert_release(condition) SDL_disabled_assert(condition)
   154 #   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
   155 #elif SDL_ASSERT_LEVEL == 1  /* release settings. */
   156 #   define SDL_assert(condition) SDL_disabled_assert(condition)
   157 #   define SDL_assert_release(condition) SDL_enabled_assert(condition)
   158 #   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
   159 #elif SDL_ASSERT_LEVEL == 2  /* normal settings. */
   160 #   define SDL_assert(condition) SDL_enabled_assert(condition)
   161 #   define SDL_assert_release(condition) SDL_enabled_assert(condition)
   162 #   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
   163 #elif SDL_ASSERT_LEVEL == 3  /* paranoid settings. */
   164 #   define SDL_assert(condition) SDL_enabled_assert(condition)
   165 #   define SDL_assert_release(condition) SDL_enabled_assert(condition)
   166 #   define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
   167 #else
   168 #   error Unknown assertion level.
   169 #endif
   170 
   171 
   172 typedef SDL_assert_state (SDLCALL *SDL_AssertionHandler)(
   173                                     const SDL_assert_data *, void *userdata);
   174 
   175 /**
   176  *  \brief Set an application-defined assertion handler.
   177  *
   178  *  This allows an app to show its own assertion UI and/or force the
   179  *  response to an assertion failure. If the app doesn't provide this, SDL
   180  *  will try to do the right thing, popping up a system-specific GUI dialog,
   181  *  and probably minimizing any fullscreen windows.
   182  *
   183  *  This callback may fire from any thread, but it runs wrapped in a mutex, so
   184  *  it will only fire from one thread at a time.
   185  *
   186  *  Setting the callback to NULL restores SDL's original internal handler.
   187  *
   188  *  This callback is NOT reset to SDL's internal handler upon SDL_Quit()!
   189  *
   190  *  \return SDL_assert_state value of how to handle the assertion failure.
   191  *  
   192  *  \param handler Callback function, called when an assertion fails.
   193  *  \param userdata A pointer passed to the callback as-is.
   194  */
   195 extern DECLSPEC void SDLCALL SDL_SetAssertionHandler(
   196                                             SDL_AssertionHandler handler,
   197                                             void *userdata);
   198 
   199 /**
   200  *  \brief Get a list of all assertion failures.
   201  *
   202  *  Get all assertions triggered since last call to SDL_ResetAssertionReport(),
   203  *  or the start of the program.
   204  *
   205  *  The proper way to examine this data looks something like this:
   206  *
   207  *  <code>
   208  *  const SDL_assert_data *item = SDL_GetAssertionReport();
   209  *  while (item->condition) {
   210  *      printf("'%s', %s (%s:%d), triggered %u times, always ignore: %s.\n",
   211  *             item->condition, item->function, item->filename,
   212  *             item->linenum, item->trigger_count,
   213  *             item->always_ignore ? "yes" : "no");
   214  *      item = item->next;
   215  *  }
   216  *  </code>
   217  *
   218  *  \return List of all assertions. This never returns NULL,
   219  *          even if there are no items.
   220  *  \sa SDL_ResetAssertionReport
   221  */
   222 extern DECLSPEC const SDL_assert_data * SDLCALL SDL_GetAssertionReport(void);
   223 
   224 /**
   225  *  \brief Reset the list of all assertion failures.
   226  *
   227  *  Reset list of all assertions triggered.
   228  *
   229  *  \sa SDL_GetAssertionReport
   230  */
   231 extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void);
   232 
   233 /* Ends C function definitions when using C++ */
   234 #ifdef __cplusplus
   235 /* *INDENT-OFF* */
   236 }
   237 /* *INDENT-ON* */
   238 #endif
   239 #include "close_code.h"
   240 
   241 #endif /* _SDL_assert_h */
   242 
   243 /* vi: set ts=4 sw=4 expandtab: */