First pass at Ryan's assertion code, minor tweaks to come.

libsdl-org · Jan 13, 2010 · 160d24a · 160d24a
1 parent e4af494
commit 160d24a
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Showing 15 changed files with 667 additions and 1 deletion.
diff --git a/Makefile.ds b/Makefile.ds
@@ -36,6 +36,7 @@ src/SDL.c \
 src/SDL_compat.c \
 src/SDL_error.c \
 src/SDL_fatal.c \
+src/SDL_assert.c \
 src/audio/nds/SDL_ndsaudio.c \
 src/audio/SDL_audio.c \
 src/audio/SDL_audiocvt.c \

diff --git a/configure.in b/configure.in
@@ -134,6 +134,32 @@ AC_C_CONST
 AC_C_INLINE
 AC_C_VOLATILE
 
+dnl See whether we want assertions for debugging/sanity checking SDL itself.
+AC_ARG_ENABLE(assertions,
+AC_HELP_STRING([--enable-assertions],
+               [Enable internal sanity checks (yes/no/release/paranoid) [[default=release]]]),
+              , enable_assertions=release)
+sdl_valid_assertion_level=no
+if test x$enable_assertions = xno; then
+    sdl_valid_assertion_level=yes
+    AC_DEFINE(SDL_ASSERT_LEVEL, 0)
+fi
+if test x$enable_assertions = xrelease; then
+    sdl_valid_assertion_level=yes
+    AC_DEFINE(SDL_ASSERT_LEVEL, 1)
+fi
+if test x$enable_assertions = xyes; then
+    sdl_valid_assertion_level=yes
+    AC_DEFINE(SDL_ASSERT_LEVEL, 2)
+fi
+if test x$enable_assertions = xparanoid; then
+    sdl_valid_assertion_level=yes
+    AC_DEFINE(SDL_ASSERT_LEVEL, 3)
+fi
+if test x$sdl_valid_assertion_level = xno; then
+    AC_MSG_ERROR([*** unknown assertion level. stop.])
+fi
+
 dnl See whether we can use gcc style dependency tracking
 AC_ARG_ENABLE(dependency-tracking,
 AC_HELP_STRING([--enable-dependency-tracking],

diff --git a/include/SDL.h b/include/SDL.h
@@ -77,6 +77,7 @@
 
 #include "SDL_main.h"
 #include "SDL_stdinc.h"
+#include "SDL_assert.h"
 #include "SDL_atomic.h"
 #include "SDL_audio.h"
 #include "SDL_cpuinfo.h"
@@ -89,8 +90,8 @@
 #include "SDL_rwops.h"
 #include "SDL_thread.h"
 #include "SDL_timer.h"
-#include "SDL_video.h"
 #include "SDL_version.h"
+#include "SDL_video.h"
 #include "SDL_compat.h"
 
 #include "begin_code.h"

diff --git a/include/SDL_assert.h b/include/SDL_assert.h
@@ -0,0 +1,151 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997-2009 Sam Lantinga
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+    Sam Lantinga
+    slouken@libsdl.org
+*/
+#include "SDL_config.h"
+
+/* This is an assert macro for SDL's internal use. Not for the public API! */
+
+#ifndef _SDL_assert_h
+#define _SDL_assert_h
+
+#ifndef SDL_ASSERT_LEVEL
+#error SDL_ASSERT_LEVEL is not defined. Please fix your SDL_config.h.
+#endif
+
+/*
+sizeof (x) makes the compiler still parse the expression even without
+assertions enabled, so the code is always checked at compile time, but
+doesn't actually generate code for it, so there are no side effects or
+expensive checks at run time, just the constant size of what x WOULD be,
+which presumably gets optimized out as unused.
+This also solves the problem of...
+
+    int somevalue = blah();
+    SDL_assert(somevalue == 1);
+
+...which would cause compiles to complain that somevalue is unused if we
+disable assertions.
+*/
+
+#define SDL_disabled_assert(condition) \
+    do { (void) sizeof ((condition)); } while (0)
+
+#if (SDL_ASSERT_LEVEL > 0)
+
+/*
+These are macros and not first class functions so that the debugger breaks
+on the assertion line and not in some random guts of SDL, and so each
+macro can have unique static variables associated with it.
+*/
+
+#if (defined(_MSC_VER) && ((_M_IX86) || (_M_X64)))
+    #define SDL_TriggerBreakpoint() __asm { int 3 }
+#elif (defined(__GNUC__) && ((__i386__) || (__x86_64__)))
+    #define SDL_TriggerBreakpoint() __asm__ __volatile__ ( "int $3\n\t" )
+#elif defined(unix)
+    #include <signal.h>
+    #define SDL_TriggerBreakpoint() raise(SIGTRAP)
+#else
+    #error Please define your platform or set SDL_ASSERT_LEVEL to 0.
+#endif
+
+#if (__STDC_VERSION__ >= 199901L) /* C99 supports __func__ as a standard. */
+#   define SDL_FUNCTION __func__
+#elif ((__GNUC__ >= 2) || defined(_MSC_VER))
+#   define SDL_FUNCTION __FUNCTION__
+#else
+#   define SDL_FUNCTION "???"
+#endif
+
+typedef enum
+{
+    SDL_ASSERTION_RETRY,  /**< Retry the assert immediately. */
+    SDL_ASSERTION_BREAK,  /**< Make the debugger trigger a breakpoint. */
+    SDL_ASSERTION_ABORT,  /**< Terminate the program. */
+    SDL_ASSERTION_IGNORE,  /**< Ignore the assert. */
+    SDL_ASSERTION_ALWAYS_IGNORE,  /**< Ignore the assert from now on. */
+} SDL_assert_state;
+
+typedef struct SDL_assert_data
+{
+    int always_ignore;
+    unsigned int trigger_count;
+    const char *condition;
+    const char *filename;
+    int linenum;
+    const char *function;
+    struct SDL_assert_data *next;
+} SDL_assert_data;
+
+SDL_assert_state SDL_ReportAssertion(SDL_assert_data *, const char *, int);
+
+/* the do {} while(0) avoids dangling else problems:
+    if (x) SDL_assert(y); else blah();
+       ... without the do/while, the "else" could attach to this macro's "if".
+   We try to handle just the minimum we need here in a macro...the loop,
+   the static vars, and break points. The heavy lifting is handled in
+   SDL_ReportAssertion(), in SDL_assert.c.
+*/
+#define SDL_enabled_assert(condition) \
+    do { \
+        while ( !(condition) ) { \
+			static struct SDL_assert_data assert_data = { \
+                0, 0, #condition, __FILE__, 0, 0, 0 \
+            }; \
+			const SDL_assert_state state = SDL_ReportAssertion(&assert_data, \
+                                                               SDL_FUNCTION, \
+															   __LINE__); \
+            if (state == SDL_ASSERTION_RETRY) { \
+                continue; /* go again. */ \
+            } else if (state == SDL_ASSERTION_BREAK) { \
+                SDL_TriggerBreakpoint(); \
+            } \
+            break; /* not retrying. */ \
+        } \
+    } while (0)
+
+#endif  /* enabled assertions support code */
+
+/* Enable various levels of assertions. */
+#if SDL_ASSERT_LEVEL == 0   /* assertions disabled */
+#   define SDL_assert(condition) SDL_disabled_assert(condition)
+#   define SDL_assert_release(condition) SDL_disabled_assert(condition)
+#   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
+#elif SDL_ASSERT_LEVEL == 1  /* release settings. */
+#   define SDL_assert(condition) SDL_enabled_assert(condition)
+#   define SDL_assert_release(condition) SDL_enabled_assert(condition)
+#   define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
+#elif SDL_ASSERT_LEVEL == 2  /* normal settings. */
+#   define SDL_assert(condition) SDL_enabled_assert(condition)
+#   define SDL_assert_release(condition) SDL_enabled_assert(condition)
+#   define SDL_assert_paranoid(condition) SDL_disabled_assert(condition)
+#elif SDL_ASSERT_LEVEL == 3  /* paranoid settings. */
+#   define SDL_assert(condition) SDL_enabled_assert(condition)
+#   define SDL_assert_release(condition) SDL_enabled_assert(condition)
+#   define SDL_assert_paranoid(condition) SDL_enabled_assert(condition)
+#else
+#   error Unknown assertion level. Please fix your SDL_config.h.
+#endif
+
+#endif /* _SDL_assert_h */
+
+/* vi: set ts=4 sw=4 expandtab: */
+
diff --git a/include/SDL_config.h.in b/include/SDL_config.h.in
@@ -162,6 +162,9 @@
 #include <stdarg.h>
 #endif /* HAVE_LIBC */
 
+/* SDL internal assertion support */
+#undef SDL_ASSERT_LEVEL
+
 /* Allow disabling of core subsystems */
 #undef SDL_AUDIO_DISABLED
 #undef SDL_CPUINFO_DISABLED

diff --git a/include/SDL_config_iphoneos.h b/include/SDL_config_iphoneos.h
@@ -25,6 +25,9 @@
 
 #include "SDL_platform.h"
 
+/* SDL internal assertion support */
+#define SDL_ASSERT_LEVEL 1
+
 #if !defined(_STDINT_H_) && (!defined(HAVE_STDINT_H) || !_HAVE_STDINT_H)
 typedef signed char int8_t;
 typedef unsigned char uint8_t;

diff --git a/include/SDL_config_macosx.h b/include/SDL_config_macosx.h
@@ -28,6 +28,9 @@
 /* This gets us MAC_OS_X_VERSION_MIN_REQUIRED... */
 #include <AvailabilityMacros.h>
 
+/* SDL internal assertion support */
+#define SDL_ASSERT_LEVEL 1
+
 /* This is a set of defines to configure the SDL features */
 
 #ifdef __LP64__

diff --git a/include/SDL_config_minimal.h b/include/SDL_config_minimal.h
@@ -33,6 +33,9 @@
 
 #include <stdarg.h>
 
+/* SDL internal assertion support */
+#define SDL_ASSERT_LEVEL 1
+
 #if !defined(_STDINT_H_) && (!defined(HAVE_STDINT_H) || !_HAVE_STDINT_H)
 typedef signed char int8_t;
 typedef unsigned char uint8_t;

diff --git a/include/SDL_config_nintendods.h b/include/SDL_config_nintendods.h
@@ -27,6 +27,9 @@
 
 /* This is a set of defines to configure the SDL features */
 
+/* SDL internal assertion support */
+#define SDL_ASSERT_LEVEL 1
+
 #if !defined(_STDINT_H_) && (!defined(HAVE_STDINT_H) || !_HAVE_STDINT_H)
 typedef signed char int8_t;
 typedef unsigned char uint8_t;

diff --git a/include/SDL_config_pandora.h b/include/SDL_config_pandora.h
@@ -28,6 +28,9 @@
 /* General platform specific identifiers */
 #include "SDL_platform.h"
 
+/* SDL internal assertion support */
+#define SDL_ASSERT_LEVEL 1
+
 #define SDL_HAS_64BIT_TYPE 1
 #define SDL_BYTEORDER 1234
 

diff --git a/include/SDL_config_win32.h b/include/SDL_config_win32.h
@@ -27,6 +27,9 @@
 
 /* This is a set of defines to configure the SDL features */
 
+/* SDL internal assertion support */
+#define SDL_ASSERT_LEVEL 1
+
 #if !defined(_STDINT_H_) && (!defined(HAVE_STDINT_H) || !_HAVE_STDINT_H)
 #if defined(__GNUC__) || defined(__DMC__) || defined(__WATCOMC__)
 #define HAVE_STDINT_H	1

diff --git a/include/SDL_config_wiz.h b/include/SDL_config_wiz.h
@@ -28,6 +28,9 @@
 /* General platform specific identifiers */
 #include "SDL_platform.h"
 
+/* SDL internal assertion support */
+#define SDL_ASSERT_LEVEL 1
+
 /* Make sure that this isn't included by Visual C++ */
 #ifdef _MSC_VER
 #error You should copy include/SDL_config.h.default to include/SDL_config.h

diff --git a/src/SDL.c b/src/SDL.c
@@ -25,6 +25,8 @@
 
 #include "SDL.h"
 #include "SDL_fatal.h"
+#include "SDL_assert.h"
+
 #if !SDL_VIDEO_DISABLED
 #include "video/SDL_leaks.h"
 #endif
@@ -52,6 +54,9 @@ extern int SDL_HelperWindowCreate(void);
 extern int SDL_HelperWindowDestroy(void);
 #endif
 
+extern int SDL_AssertionsInit(void);
+extern void SDL_AssertionsQuit(void);
+
 /* The initialized subsystems */
 static Uint32 SDL_initialized = 0;
 static Uint32 ticks_started = 0;
@@ -153,6 +158,10 @@ SDL_Init(Uint32 flags)
     }
 #endif
 
+    if (SDL_AssertionsInit() < 0) {
+        return -1;
+    }
+
     /* Clear the error message */
     SDL_ClearError();
 
@@ -171,6 +180,21 @@ SDL_Init(Uint32 flags)
     if (!(flags & SDL_INIT_NOPARACHUTE)) {
         SDL_InstallParachute();
     }
+
+    /* brief sanity checks for the sanity checks.  :)  */
+    SDL_assert(1);
+    SDL_assert_release(1);
+    SDL_assert_paranoid(1);
+    SDL_assert(0 || 1);
+    SDL_assert_release(0 || 1);
+    SDL_assert_paranoid(0 || 1);
+
+#if 0   /* enable this to test assertion failures. */
+    SDL_assert_release(1 == 2);
+    SDL_assert_release(5 < 4);
+    SDL_assert_release(0 && "This is a test");
+#endif
+
     return (0);
 }
 
@@ -239,6 +263,7 @@ SDL_Quit(void)
     fflush(stdout);
 #endif
 
+    /* !!! FIXME: make this an assertion. */
     /* Print the number of surfaces not freed */
     if (surfaces_allocated != 0) {
         fprintf(stderr, "SDL Warning: %d SDL surfaces extant\n",
@@ -253,6 +278,8 @@ SDL_Quit(void)
     /* Uninstall any parachute signal handlers */
     SDL_UninstallParachute();
 
+    SDL_AssertionsQuit();
+
 #if !SDL_THREADS_DISABLED && SDL_THREAD_PTH
     pth_kill();
 #endif