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SDL_assert.h
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,
101  SDL_ASSERTION_BREAK,
102  SDL_ASSERTION_ABORT,
103  SDL_ASSERTION_IGNORE,
104  SDL_ASSERTION_ALWAYS_IGNORE
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;
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 #if defined(__clang__)
125 #if __has_feature(attribute_analyzer_noreturn)
126 /* this tells Clang's static analysis that we're a custom assert function,
127  and that the analyzer should assume the condition was always true past this
128  SDL_assert test. */
129  __attribute__((analyzer_noreturn))
130 #endif
131 #endif
132 ;
133 
134 /* the do {} while(0) avoids dangling else problems:
135  if (x) SDL_assert(y); else blah();
136  ... without the do/while, the "else" could attach to this macro's "if".
137  We try to handle just the minimum we need here in a macro...the loop,
138  the static vars, and break points. The heavy lifting is handled in
139  SDL_ReportAssertion(), in SDL_assert.c.
140 */
141 #define SDL_enabled_assert(condition) \
142  do { \
143  while ( !(condition) ) { \
144  static struct SDL_assert_data assert_data = { \
145  0, 0, #condition, 0, 0, 0, 0 \
146  }; \
147  const SDL_assert_state state = SDL_ReportAssertion(&assert_data, \
148  SDL_FUNCTION, \
149  SDL_FILE, \
150  SDL_LINE); \
151  if (state == SDL_ASSERTION_RETRY) { \
152  continue; /* go again. */ \
153  } else if (state == SDL_ASSERTION_BREAK) { \
154  SDL_TriggerBreakpoint(); \
155  } \
156  break; /* not retrying. */ \
157  } \
158  } while (SDL_NULL_WHILE_LOOP_CONDITION)
159 
160 #endif /* enabled assertions support code */
161 
162 /* Enable various levels of assertions. */
163 #if SDL_ASSERT_LEVEL == 0 /* assertions disabled */
164 # define SDL_assert(condition) SDL_disabled_assert(condition)
165 # define SDL_assert_release(condition) SDL_disabled_assert(condition)
166 # define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
167 #elif SDL_ASSERT_LEVEL == 1 /* release settings. */
168 # define SDL_assert(condition) SDL_disabled_assert(condition)
169 # define SDL_assert_release(condition) SDL_enabled_assert(condition)
170 # define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
171 #elif SDL_ASSERT_LEVEL == 2 /* normal settings. */
172 # define SDL_assert(condition) SDL_enabled_assert(condition)
173 # define SDL_assert_release(condition) SDL_enabled_assert(condition)
174 # define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
175 #elif SDL_ASSERT_LEVEL == 3 /* paranoid settings. */
176 # define SDL_assert(condition) SDL_enabled_assert(condition)
177 # define SDL_assert_release(condition) SDL_enabled_assert(condition)
178 # define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
179 #else
180 # error Unknown assertion level.
181 #endif
182 
183 /* this assertion is never disabled at any level. */
184 #define SDL_assert_always(condition) SDL_enabled_assert(condition)
185 
186 
187 typedef SDL_assert_state (SDLCALL *SDL_AssertionHandler)(
188  const SDL_assert_data* data, void* userdata);
189 
210 extern DECLSPEC void SDLCALL SDL_SetAssertionHandler(
211  SDL_AssertionHandler handler,
212  void *userdata);
213 
224 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetDefaultAssertionHandler(void);
225 
241 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetAssertionHandler(void **puserdata);
242 
265 extern DECLSPEC const SDL_assert_data * SDLCALL SDL_GetAssertionReport(void);
266 
274 extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void);
275 
276 /* Ends C function definitions when using C++ */
277 #ifdef __cplusplus
278 }
279 #endif
280 #include "close_code.h"
281 
282 #endif /* _SDL_assert_h */
283 
284 /* vi: set ts=4 sw=4 expandtab: */
Definition: SDL_assert.h:107