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SDL_assert.h
1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2020 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(__clang__)) && (defined(__i386__) || defined(__x86_64__))) )
55  #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "int $3\n\t" )
56 #elif ( defined(__APPLE__) && defined(__arm64__) ) /* this might work on other ARM targets, but this is a known quantity... */
57  #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "brk #22\n\t" )
58 #elif defined(__386__) && defined(__WATCOMC__)
59  #define SDL_TriggerBreakpoint() { _asm { int 0x03 } }
60 #elif defined(HAVE_SIGNAL_H) && !defined(__WATCOMC__)
61  #include <signal.h>
62  #define SDL_TriggerBreakpoint() raise(SIGTRAP)
63 #else
64  /* How do we trigger breakpoints on this platform? */
65  #define SDL_TriggerBreakpoint()
66 #endif
67 
68 #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 supports __func__ as a standard. */
69 # define SDL_FUNCTION __func__
70 #elif ((__GNUC__ >= 2) || defined(_MSC_VER) || defined (__WATCOMC__))
71 # define SDL_FUNCTION __FUNCTION__
72 #else
73 # define SDL_FUNCTION "???"
74 #endif
75 #define SDL_FILE __FILE__
76 #define SDL_LINE __LINE__
77 
78 /*
79 sizeof (x) makes the compiler still parse the expression even without
80 assertions enabled, so the code is always checked at compile time, but
81 doesn't actually generate code for it, so there are no side effects or
82 expensive checks at run time, just the constant size of what x WOULD be,
83 which presumably gets optimized out as unused.
84 This also solves the problem of...
85 
86  int somevalue = blah();
87  SDL_assert(somevalue == 1);
88 
89 ...which would cause compiles to complain that somevalue is unused if we
90 disable assertions.
91 */
92 
93 /* "while (0,0)" fools Microsoft's compiler's /W4 warning level into thinking
94  this condition isn't constant. And looks like an owl's face! */
95 #ifdef _MSC_VER /* stupid /W4 warnings. */
96 #define SDL_NULL_WHILE_LOOP_CONDITION (0,0)
97 #else
98 #define SDL_NULL_WHILE_LOOP_CONDITION (0)
99 #endif
100 
101 #define SDL_disabled_assert(condition) \
102  do { (void) sizeof ((condition)); } while (SDL_NULL_WHILE_LOOP_CONDITION)
103 
104 typedef enum
105 {
106  SDL_ASSERTION_RETRY,
107  SDL_ASSERTION_BREAK,
108  SDL_ASSERTION_ABORT,
109  SDL_ASSERTION_IGNORE,
110  SDL_ASSERTION_ALWAYS_IGNORE
111 } SDL_AssertState;
112 
113 typedef struct SDL_AssertData
114 {
115  int always_ignore;
116  unsigned int trigger_count;
117  const char *condition;
118  const char *filename;
119  int linenum;
120  const char *function;
121  const struct SDL_AssertData *next;
123 
124 #if (SDL_ASSERT_LEVEL > 0)
125 
126 /* Never call this directly. Use the SDL_assert* macros. */
127 extern DECLSPEC SDL_AssertState SDLCALL SDL_ReportAssertion(SDL_AssertData *,
128  const char *,
129  const char *, int)
130 #if defined(__clang__)
131 #if __has_feature(attribute_analyzer_noreturn)
132 /* this tells Clang's static analysis that we're a custom assert function,
133  and that the analyzer should assume the condition was always true past this
134  SDL_assert test. */
135  __attribute__((analyzer_noreturn))
136 #endif
137 #endif
138 ;
139 
140 /* the do {} while(0) avoids dangling else problems:
141  if (x) SDL_assert(y); else blah();
142  ... without the do/while, the "else" could attach to this macro's "if".
143  We try to handle just the minimum we need here in a macro...the loop,
144  the static vars, and break points. The heavy lifting is handled in
145  SDL_ReportAssertion(), in SDL_assert.c.
146 */
147 #define SDL_enabled_assert(condition) \
148  do { \
149  while ( !(condition) ) { \
150  static struct SDL_AssertData sdl_assert_data = { \
151  0, 0, #condition, 0, 0, 0, 0 \
152  }; \
153  const SDL_AssertState sdl_assert_state = SDL_ReportAssertion(&sdl_assert_data, SDL_FUNCTION, SDL_FILE, SDL_LINE); \
154  if (sdl_assert_state == SDL_ASSERTION_RETRY) { \
155  continue; /* go again. */ \
156  } else if (sdl_assert_state == SDL_ASSERTION_BREAK) { \
157  SDL_TriggerBreakpoint(); \
158  } \
159  break; /* not retrying. */ \
160  } \
161  } while (SDL_NULL_WHILE_LOOP_CONDITION)
162 
163 #endif /* enabled assertions support code */
164 
165 /* Enable various levels of assertions. */
166 #if SDL_ASSERT_LEVEL == 0 /* assertions disabled */
167 # define SDL_assert(condition) SDL_disabled_assert(condition)
168 # define SDL_assert_release(condition) SDL_disabled_assert(condition)
169 # define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
170 #elif SDL_ASSERT_LEVEL == 1 /* release settings. */
171 # define SDL_assert(condition) SDL_disabled_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 == 2 /* normal 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_disabled_assert(condition)
178 #elif SDL_ASSERT_LEVEL == 3 /* paranoid settings. */
179 # define SDL_assert(condition) SDL_enabled_assert(condition)
180 # define SDL_assert_release(condition) SDL_enabled_assert(condition)
181 # define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
182 #else
183 # error Unknown assertion level.
184 #endif
185 
186 /* this assertion is never disabled at any level. */
187 #define SDL_assert_always(condition) SDL_enabled_assert(condition)
188 
189 
190 typedef SDL_AssertState (SDLCALL *SDL_AssertionHandler)(
191  const SDL_AssertData* data, void* userdata);
192 
213 extern DECLSPEC void SDLCALL SDL_SetAssertionHandler(
214  SDL_AssertionHandler handler,
215  void *userdata);
216 
227 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetDefaultAssertionHandler(void);
228 
244 extern DECLSPEC SDL_AssertionHandler SDLCALL SDL_GetAssertionHandler(void **puserdata);
245 
268 extern DECLSPEC const SDL_AssertData * SDLCALL SDL_GetAssertionReport(void);
269 
277 extern DECLSPEC void SDLCALL SDL_ResetAssertionReport(void);
278 
279 
280 /* these had wrong naming conventions until 2.0.4. Please update your app! */
281 #define SDL_assert_state SDL_AssertState
282 #define SDL_assert_data SDL_AssertData
283 
284 
285 /* Ends C function definitions when using C++ */
286 #ifdef __cplusplus
287 }
288 #endif
289 #include "close_code.h"
290 
291 #endif /* SDL_assert_h_ */
292 
293 /* vi: set ts=4 sw=4 expandtab: */
close_code.h
begin_code.h
SDL_AssertData
Definition: SDL_assert.h:114