First pass at Ryan's assertion code, minor tweaks to come.
2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997-2009 Sam Lantinga
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.
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.
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
22 #include "SDL_config.h"
24 /* This is an assert macro for SDL's internal use. Not for the public API! */
29 #ifndef SDL_ASSERT_LEVEL
30 #error SDL_ASSERT_LEVEL is not defined. Please fix your SDL_config.h.
34 sizeof (x) makes the compiler still parse the expression even without
35 assertions enabled, so the code is always checked at compile time, but
36 doesn't actually generate code for it, so there are no side effects or
37 expensive checks at run time, just the constant size of what x WOULD be,
38 which presumably gets optimized out as unused.
39 This also solves the problem of...
41 int somevalue = blah();
42 SDL_assert(somevalue == 1);
44 ...which would cause compiles to complain that somevalue is unused if we
48 #define SDL_disabled_assert(condition) \
49 do { (void) sizeof ((condition)); } while (0)
51 #if (SDL_ASSERT_LEVEL > 0)
54 These are macros and not first class functions so that the debugger breaks
55 on the assertion line and not in some random guts of SDL, and so each
56 macro can have unique static variables associated with it.
59 #if (defined(_MSC_VER) && ((_M_IX86) || (_M_X64)))
60 #define SDL_TriggerBreakpoint() __asm { int 3 }
61 #elif (defined(__GNUC__) && ((__i386__) || (__x86_64__)))
62 #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "int $3\n\t" )
65 #define SDL_TriggerBreakpoint() raise(SIGTRAP)
67 #error Please define your platform or set SDL_ASSERT_LEVEL to 0.
70 #if (__STDC_VERSION__ >= 199901L) /* C99 supports __func__ as a standard. */
71 # define SDL_FUNCTION __func__
72 #elif ((__GNUC__ >= 2) || defined(_MSC_VER))
73 # define SDL_FUNCTION __FUNCTION__
75 # define SDL_FUNCTION "???"
80 SDL_ASSERTION_RETRY, /**< Retry the assert immediately. */
81 SDL_ASSERTION_BREAK, /**< Make the debugger trigger a breakpoint. */
82 SDL_ASSERTION_ABORT, /**< Terminate the program. */
83 SDL_ASSERTION_IGNORE, /**< Ignore the assert. */
84 SDL_ASSERTION_ALWAYS_IGNORE, /**< Ignore the assert from now on. */
87 typedef struct SDL_assert_data
90 unsigned int trigger_count;
91 const char *condition;
95 struct SDL_assert_data *next;
98 SDL_assert_state SDL_ReportAssertion(SDL_assert_data *, const char *, int);
100 /* the do {} while(0) avoids dangling else problems:
101 if (x) SDL_assert(y); else blah();
102 ... without the do/while, the "else" could attach to this macro's "if".
103 We try to handle just the minimum we need here in a macro...the loop,
104 the static vars, and break points. The heavy lifting is handled in
105 SDL_ReportAssertion(), in SDL_assert.c.
107 #define SDL_enabled_assert(condition) \
109 while ( !(condition) ) { \
110 static struct SDL_assert_data assert_data = { \
111 0, 0, #condition, __FILE__, 0, 0, 0 \
113 const SDL_assert_state state = SDL_ReportAssertion(&assert_data, \
116 if (state == SDL_ASSERTION_RETRY) { \
117 continue; /* go again. */ \
118 } else if (state == SDL_ASSERTION_BREAK) { \
119 SDL_TriggerBreakpoint(); \
121 break; /* not retrying. */ \
125 #endif /* enabled assertions support code */
127 /* Enable various levels of assertions. */
128 #if SDL_ASSERT_LEVEL == 0 /* assertions disabled */
129 # define SDL_assert(condition) SDL_disabled_assert(condition)
130 # define SDL_assert_release(condition) SDL_disabled_assert(condition)
131 # define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
132 #elif SDL_ASSERT_LEVEL == 1 /* release settings. */
133 # define SDL_assert(condition) SDL_enabled_assert(condition)
134 # define SDL_assert_release(condition) SDL_enabled_assert(condition)
135 # define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
136 #elif SDL_ASSERT_LEVEL == 2 /* normal settings. */
137 # define SDL_assert(condition) SDL_enabled_assert(condition)
138 # define SDL_assert_release(condition) SDL_enabled_assert(condition)
139 # define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
140 #elif SDL_ASSERT_LEVEL == 3 /* paranoid settings. */
141 # define SDL_assert(condition) SDL_enabled_assert(condition)
142 # define SDL_assert_release(condition) SDL_enabled_assert(condition)
143 # define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
145 # error Unknown assertion level. Please fix your SDL_config.h.
148 #endif /* _SDL_assert_h */
150 /* vi: set ts=4 sw=4 expandtab: */