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SDL_assert.h
1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2016 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(__NACL__) && 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 /* "while (0,0)" fools Microsoft's compiler's /W4 warning level into thinking
90  this condition isn't constant. And looks like an owl's face! */
91 #ifdef _MSC_VER /* stupid /W4 warnings. */
92 #define SDL_NULL_WHILE_LOOP_CONDITION (0,0)
93 #else
94 #define SDL_NULL_WHILE_LOOP_CONDITION (0)
95 #endif
96 
97 #define SDL_disabled_assert(condition) \
98  do { (void) sizeof ((condition)); } while (SDL_NULL_WHILE_LOOP_CONDITION)
99 
100 typedef enum
101 {
102  SDL_ASSERTION_RETRY,
103  SDL_ASSERTION_BREAK,
104  SDL_ASSERTION_ABORT,
105  SDL_ASSERTION_IGNORE,
106  SDL_ASSERTION_ALWAYS_IGNORE
107 } SDL_AssertState;
108 
109 typedef struct SDL_AssertData
110 {
111  int always_ignore;
112  unsigned int trigger_count;
113  const char *condition;
114  const char *filename;
115  int linenum;
116  const char *function;
117  const struct SDL_AssertData *next;
119 
120 #if (SDL_ASSERT_LEVEL > 0)
121 
122 /* Never call this directly. Use the SDL_assert* macros. */
123 extern DECLSPEC SDL_AssertState SDLCALL SDL_ReportAssertion(SDL_AssertData *,
124  const char *,
125  const char *, int)
126 #if defined(__clang__)
127 #if __has_feature(attribute_analyzer_noreturn)
128 /* this tells Clang's static analysis that we're a custom assert function,
129  and that the analyzer should assume the condition was always true past this
130  SDL_assert test. */
131  __attribute__((analyzer_noreturn))
132 #endif
133 #endif
134 ;
135 
136 /* the do {} while(0) avoids dangling else problems:
137  if (x) SDL_assert(y); else blah();
138  ... without the do/while, the "else" could attach to this macro's "if".
139  We try to handle just the minimum we need here in a macro...the loop,
140  the static vars, and break points. The heavy lifting is handled in
141  SDL_ReportAssertion(), in SDL_assert.c.
142 */
143 #define SDL_enabled_assert(condition) \
144  do { \
145  while ( !(condition) ) { \
146  static struct SDL_AssertData sdl_assert_data = { \
147  0, 0, #condition, 0, 0, 0, 0 \
148  }; \
149  const SDL_AssertState sdl_assert_state = SDL_ReportAssertion(&sdl_assert_data, SDL_FUNCTION, SDL_FILE, SDL_LINE); \
150  if (sdl_assert_state == SDL_ASSERTION_RETRY) { \
151  continue; /* go again. */ \
152  } else if (sdl_assert_state == SDL_ASSERTION_BREAK) { \
153  SDL_TriggerBreakpoint(); \
154  } \
155  break; /* not retrying. */ \
156  } \
157  } while (SDL_NULL_WHILE_LOOP_CONDITION)
158 
159 #endif /* enabled assertions support code */
160 
161 /* Enable various levels of assertions. */
162 #if SDL_ASSERT_LEVEL == 0 /* assertions disabled */
163 # define SDL_assert(condition) SDL_disabled_assert(condition)
164 # define SDL_assert_release(condition) SDL_disabled_assert(condition)
165 # define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
166 #elif SDL_ASSERT_LEVEL == 1 /* release settings. */
167 # define SDL_assert(condition) SDL_disabled_assert(condition)
168 # define SDL_assert_release(condition) SDL_enabled_assert(condition)
169 # define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
170 #elif SDL_ASSERT_LEVEL == 2 /* normal settings. */
171 # define SDL_assert(condition) SDL_enabled_assert(condition)
172 # define SDL_assert_release(condition) SDL_enabled_assert(condition)
173 # define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
174 #elif SDL_ASSERT_LEVEL == 3 /* paranoid settings. */
175 # define SDL_assert(condition) SDL_enabled_assert(condition)
176 # define SDL_assert_release(condition) SDL_enabled_assert(condition)
177 # define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
178 #else
179 # error Unknown assertion level.
180 #endif
181 
182 /* this assertion is never disabled at any level. */
183 #define SDL_assert_always(condition) SDL_enabled_assert(condition)
184 
185 
186 typedef SDL_AssertState (SDLCALL *SDL_AssertionHandler)(
187  const SDL_AssertData* data, void* userdata);
188 
209 extern DECLSPEC void SDLCALL SDL_SetAssertionHandler(
210  SDL_AssertionHandler handler,
211  void *userdata);
212 
223 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetDefaultAssertionHandler(void);
224 
240 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetAssertionHandler(void **puserdata);
241 
264 extern DECLSPEC const SDL_AssertData * SDLCALL SDL_GetAssertionReport(void);
265 
273 extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void);
274 
275 
276 /* these had wrong naming conventions until 2.0.4. Please update your app! */
277 #define SDL_assert_state SDL_AssertState
278 #define SDL_assert_data SDL_AssertData
279 
280 
281 /* Ends C function definitions when using C++ */
282 #ifdef __cplusplus
283 }
284 #endif
285 #include "close_code.h"
286 
287 #endif /* _SDL_assert_h */
288 
289 /* vi: set ts=4 sw=4 expandtab: */
Definition: SDL_assert.h:109