diff SDL3/SDL_begin_code.h @ 1:20d02a178406 default tip

*: check in everything else yay
author Paper <paper@tflc.us>
date Mon, 05 Jan 2026 02:15:46 -0500
parents
children
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SDL3/SDL_begin_code.h	Mon Jan 05 02:15:46 2026 -0500
@@ -0,0 +1,553 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+
+/* WIKI CATEGORY: BeginCode */
+
+/**
+ * # CategoryBeginCode
+ *
+ * `SDL_begin_code.h` sets things up for C dynamic library function
+ * definitions, static inlined functions, and structures aligned at 4-byte
+ * alignment. If you don't like ugly C preprocessor code, don't look at this
+ * file. :)
+ *
+ * SDL's headers use this; applications generally should not include this
+ * header directly.
+ */
+
+/* This shouldn't be nested -- included it around code only. */
+#ifdef SDL_begin_code_h
+#error Nested inclusion of SDL_begin_code.h
+#endif
+#define SDL_begin_code_h
+
+#ifdef SDL_WIKI_DOCUMENTATION_SECTION
+
+/**
+ * A macro to tag a symbol as deprecated.
+ *
+ * A function is marked deprecated by adding this macro to its declaration:
+ *
+ * ```c
+ * extern SDL_DEPRECATED int ThisFunctionWasABadIdea(void);
+ * ```
+ *
+ * Compilers with deprecation support can give a warning when a deprecated
+ * function is used. This symbol may be used in SDL's headers, but apps are
+ * welcome to use it for their own interfaces as well.
+ *
+ * SDL, on occasion, might deprecate a function for various reasons. However,
+ * SDL never removes symbols before major versions, so deprecated interfaces
+ * in SDL3 will remain available until SDL4, where it would be expected an app
+ * would have to take steps to migrate anyhow.
+ *
+ * On compilers without a deprecation mechanism, this is defined to nothing,
+ * and using a deprecated function will not generate a warning.
+ *
+ * \since This macro is available since SDL 3.2.0.
+ */
+#define SDL_DEPRECATED __attribute__((deprecated))
+
+/**
+ * A macro to tag a symbol as a public API.
+ *
+ * SDL uses this macro for all its public functions. On some targets, it is
+ * used to signal to the compiler that this function needs to be exported from
+ * a shared library, but it might have other side effects.
+ *
+ * This symbol is used in SDL's headers, but apps and other libraries are
+ * welcome to use it for their own interfaces as well.
+ *
+ * \since This macro is available since SDL 3.2.0.
+ */
+#define SDL_DECLSPEC __attribute__ ((visibility("default")))
+
+/**
+ * A macro to set a function's calling conventions.
+ *
+ * SDL uses this macro for all its public functions, and any callbacks it
+ * defines. This macro guarantees that calling conventions match between SDL
+ * and the app, even if the two were built with different compilers or
+ * optimization settings.
+ *
+ * When writing a callback function, it is very important for it to be
+ * correctly tagged with SDLCALL, as mismatched calling conventions can cause
+ * strange behaviors and can be difficult to diagnose. Plus, on many
+ * platforms, SDLCALL is defined to nothing, so compilers won't be able to
+ * warn that the tag is missing.
+ *
+ * This symbol is used in SDL's headers, but apps and other libraries are
+ * welcome to use it for their own interfaces as well.
+ *
+ * \since This macro is available since SDL 3.2.0.
+ */
+#define SDLCALL __cdecl
+
+/**
+ * A macro to request a function be inlined.
+ *
+ * This is a hint to the compiler to inline a function. The compiler is free
+ * to ignore this request. On compilers without inline support, this is
+ * defined to nothing.
+ *
+ * \since This macro is available since SDL 3.2.0.
+ */
+#define SDL_INLINE __inline
+
+/**
+ * A macro to demand a function be inlined.
+ *
+ * This is a command to the compiler to inline a function. SDL uses this macro
+ * in its public headers for a handful of simple functions. On compilers
+ * without forceinline support, this is defined to `static SDL_INLINE`, which
+ * is often good enough.
+ *
+ * This symbol is used in SDL's headers, but apps and other libraries are
+ * welcome to use it for their own interfaces as well.
+ *
+ * \since This macro is available since SDL 3.2.0.
+ */
+#define SDL_FORCE_INLINE __forceinline
+
+/**
+ * A macro to tag a function as never-returning.
+ *
+ * This is a hint to the compiler that a function does not return. An example
+ * of a function like this is the C runtime's exit() function.
+ *
+ * This hint can lead to code optimizations, and help analyzers understand
+ * code flow better. On compilers without noreturn support, this is defined to
+ * nothing.
+ *
+ * This symbol is used in SDL's headers, but apps and other libraries are
+ * welcome to use it for their own interfaces as well.
+ *
+ * \since This macro is available since SDL 3.2.0.
+ */
+#define SDL_NORETURN __attribute__((noreturn))
+
+/**
+ * A macro to tag a function as never-returning (for analysis purposes).
+ *
+ * This is almost identical to SDL_NORETURN, except functions marked with this
+ * _can_ actually return. The difference is that this isn't used for code
+ * generation, but rather static analyzers use this information to assume
+ * truths about program state and available code paths. Specifically, this tag
+ * is useful for writing an assertion mechanism. Indeed, SDL_assert uses this
+ * tag behind the scenes. Generally, apps that don't understand the specific
+ * use-case for this tag should avoid using it directly.
+ *
+ * On compilers without analyzer_noreturn support, this is defined to nothing.
+ *
+ * This symbol is used in SDL's headers, but apps and other libraries are
+ * welcome to use it for their own interfaces as well.
+ *
+ * \since This macro is available since SDL 3.2.0.
+ */
+#define SDL_ANALYZER_NORETURN __attribute__((analyzer_noreturn))
+
+
+/**
+ * A macro to signal that a case statement without a `break` is intentional.
+ *
+ * C compilers have gotten more aggressive about warning when a switch's
+ * `case` block does not end with a `break` or other flow control statement,
+ * flowing into the next case's code, as this is a common accident that leads
+ * to strange bugs. But sometimes falling through to the next case is the
+ * correct and desired behavior. This symbol lets an app communicate this
+ * intention to the compiler, so it doesn't generate a warning.
+ *
+ * It is used like this:
+ *
+ * ```c
+ * switch (x) {
+ *     case 1:
+ *         DoSomethingOnlyForOne();
+ *         SDL_FALLTHROUGH;  // tell the compiler this was intentional.
+ *     case 2:
+ *         DoSomethingForOneAndTwo();
+ *         break;
+ * }
+ * ```
+ *
+ * \since This macro is available since SDL 3.2.0.
+ */
+#define SDL_FALLTHROUGH [[fallthrough]]
+
+/**
+ * A macro to tag a function's return value as critical.
+ *
+ * This is a hint to the compiler that a function's return value should not be
+ * ignored.
+ *
+ * If an NODISCARD function's return value is thrown away (the function is
+ * called as if it returns `void`), the compiler will issue a warning.
+ *
+ * While it's generally good practice to check return values for errors, often
+ * times legitimate programs do not for good reasons. Be careful about what
+ * functions are tagged as NODISCARD. It operates best when used on a function
+ * that's failure is surprising and catastrophic; a good example would be a
+ * program that checks the return values of all its file write function calls
+ * but not the call to close the file, which it assumes incorrectly never
+ * fails.
+ *
+ * Function callers that want to throw away a NODISCARD return value can call
+ * the function with a `(void)` cast, which informs the compiler the act is
+ * intentional.
+ *
+ * On compilers without nodiscard support, this is defined to nothing.
+ *
+ * \since This macro is available since SDL 3.2.0.
+ */
+#define SDL_NODISCARD [[nodiscard]]
+
+/**
+ * A macro to tag a function as an allocator.
+ *
+ * This is a hint to the compiler that a function is an allocator, like
+ * malloc(), with certain rules. A description of how GCC treats this hint is
+ * here:
+ *
+ * https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-malloc-function-attribute
+ *
+ * On compilers without allocator tag support, this is defined to nothing.
+ *
+ * Most apps don't need to, and should not, use this directly.
+ *
+ * \since This macro is available since SDL 3.2.0.
+ */
+#define SDL_MALLOC __declspec(allocator) __desclspec(restrict)
+
+/**
+ * A macro to tag a function as returning a certain allocation.
+ *
+ * This is a hint to the compiler that a function allocates and returns a
+ * specific amount of memory based on one of its arguments. For example, the C
+ * runtime's malloc() function could use this macro with an argument of 1
+ * (first argument to malloc is the size of the allocation).
+ *
+ * On compilers without alloc_size support, this is defined to nothing.
+ *
+ * Most apps don't need to, and should not, use this directly.
+ *
+ * \since This macro is available since SDL 3.2.0.
+ */
+#define SDL_ALLOC_SIZE(p) __attribute__((alloc_size(p)))
+
+/**
+ * A macro to tag a pointer variable, to help with pointer aliasing.
+ *
+ * A good explanation of the restrict keyword is here:
+ *
+ * https://en.wikipedia.org/wiki/Restrict
+ *
+ * On compilers without restrict support, this is defined to nothing.
+ *
+ * \since This macro is available since SDL 3.4.0.
+ */
+#define SDL_RESTRICT __restrict
+
+/**
+ * Check if the compiler supports a given builtin functionality.
+ *
+ * This allows preprocessor checks for things that otherwise might fail to
+ * compile.
+ *
+ * Supported by virtually all clang versions and more-recent GCCs. Use this
+ * instead of checking the clang version if possible.
+ *
+ * On compilers without has_builtin support, this is defined to 0 (always
+ * false).
+ *
+ * \since This macro is available since SDL 3.2.0.
+ */
+#define SDL_HAS_BUILTIN(x) __has_builtin(x)
+
+/**
+ * A macro to specify data alignment.
+ *
+ * This informs the compiler that a given datatype or variable must be aligned
+ * to a specific byte count.
+ *
+ * For example:
+ *
+ * ```c
+ * // make sure this is struct is aligned to 16 bytes for SIMD access.
+ * typedef struct {
+ *    float x, y, z, w;
+ * } SDL_ALIGNED(16) MySIMDAlignedData;
+ *
+ * // make sure this one field in a struct is aligned to 16 bytes for SIMD access.
+ * typedef struct {
+ *    SomeStuff stuff;
+ *    float SDL_ALIGNED(16) position[4];
+ *    SomeOtherStuff other_stuff;
+ * } MyStruct;
+ *
+ * // make sure this variable is aligned to 32 bytes.
+ * int SDL_ALIGNED(32) myval = 0;
+ * ```
+ *
+ * Alignment is only guaranteed for things the compiler places: local
+ * variables on the stack and global/static variables. To dynamically allocate
+ * something that respects this alignment, use SDL_aligned_alloc() or some
+ * other mechanism.
+ *
+ * On compilers without alignment support, this macro is defined to an invalid
+ * symbol, to make it clear that the current compiler is likely to generate
+ * incorrect code when it sees this macro.
+ *
+ * \param x the byte count to align to, so the data's address will be a
+ *          multiple of this value.
+ *
+ * \since This macro is available since SDL 3.4.0.
+ */
+#define SDL_ALIGNED(x) __attribute__((aligned(x)))
+
+/* end of wiki documentation section. */
+#endif
+
+/* `restrict` is from C99, but __restrict works with both Visual Studio and GCC. */
+#ifndef SDL_RESTRICT
+#  if defined(restrict) || ((defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)))
+#    define SDL_RESTRICT restrict
+#  elif defined(_MSC_VER) || defined(__GNUC__) || defined(__clang__)
+#    define SDL_RESTRICT __restrict
+#  else
+#    define SDL_RESTRICT
+#  endif
+#endif
+
+#ifndef SDL_HAS_BUILTIN
+#ifdef __has_builtin
+#define SDL_HAS_BUILTIN(x) __has_builtin(x)
+#else
+#define SDL_HAS_BUILTIN(x) 0
+#endif
+#endif
+
+#ifndef SDL_DEPRECATED
+#  if defined(__GNUC__) && (__GNUC__ >= 4)  /* technically, this arrived in gcc 3.1, but oh well. */
+#    define SDL_DEPRECATED __attribute__((deprecated))
+#  elif defined(_MSC_VER)
+#    define SDL_DEPRECATED __declspec(deprecated)
+#  else
+#    define SDL_DEPRECATED
+#  endif
+#endif
+
+#ifndef SDL_UNUSED
+#  ifdef __GNUC__
+#    define SDL_UNUSED __attribute__((unused))
+#  else
+#    define SDL_UNUSED
+#  endif
+#endif
+
+/* Some compilers use a special export keyword */
+#ifndef SDL_DECLSPEC
+# if defined(SDL_PLATFORM_WINDOWS)
+#  ifdef DLL_EXPORT
+#   define SDL_DECLSPEC __declspec(dllexport)
+#  else
+#   define SDL_DECLSPEC
+#  endif
+# else
+#  if defined(__GNUC__) && __GNUC__ >= 4
+#   define SDL_DECLSPEC __attribute__ ((visibility("default")))
+#  else
+#   define SDL_DECLSPEC
+#  endif
+# endif
+#endif
+
+/* By default SDL uses the C calling convention */
+#ifndef SDLCALL
+#if defined(SDL_PLATFORM_WINDOWS) && !defined(__GNUC__)
+#define SDLCALL __cdecl
+#else
+#define SDLCALL
+#endif
+#endif /* SDLCALL */
+
+/* Force structure packing at 4 byte alignment.
+   This is necessary if the header is included in code which has structure
+   packing set to an alternate value, say for loading structures from disk.
+   The packing is reset to the previous value in SDL_close_code.h
+ */
+#if defined(_MSC_VER) || defined(__MWERKS__) || defined(__BORLANDC__)
+#ifdef _MSC_VER
+#pragma warning(disable: 4103)
+#endif
+#ifdef __clang__
+#pragma clang diagnostic ignored "-Wpragma-pack"
+#endif
+#ifdef __BORLANDC__
+#pragma nopackwarning
+#endif
+#ifdef _WIN64
+/* Use 8-byte alignment on 64-bit architectures, so pointers are aligned */
+#pragma pack(push,8)
+#else
+#pragma pack(push,4)
+#endif
+#endif /* Compiler needs structure packing set */
+
+#ifndef SDL_INLINE
+#ifdef __GNUC__
+#define SDL_INLINE __inline__
+#elif defined(_MSC_VER) || defined(__BORLANDC__) || \
+      defined(__DMC__) || defined(__SC__) || \
+      defined(__WATCOMC__) || defined(__LCC__) || \
+      defined(__DECC) || defined(__CC_ARM)
+#define SDL_INLINE __inline
+#ifndef __inline__
+#define __inline__ __inline
+#endif
+#else
+#define SDL_INLINE inline
+#ifndef __inline__
+#define __inline__ inline
+#endif
+#endif
+#endif /* SDL_INLINE not defined */
+
+#ifndef SDL_FORCE_INLINE
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+#define SDL_FORCE_INLINE __forceinline
+#elif ( (defined(__GNUC__) && (__GNUC__ >= 4)) || defined(__clang__) )
+#define SDL_FORCE_INLINE __attribute__((always_inline)) static __inline__
+#else
+#define SDL_FORCE_INLINE static SDL_INLINE
+#endif
+#endif /* SDL_FORCE_INLINE not defined */
+
+#ifndef SDL_NORETURN
+#if defined(__GNUC__)
+#define SDL_NORETURN __attribute__((noreturn))
+#elif defined(_MSC_VER)
+#define SDL_NORETURN __declspec(noreturn)
+#else
+#define SDL_NORETURN
+#endif
+#endif /* SDL_NORETURN not defined */
+
+#ifdef __clang__
+#if __has_feature(attribute_analyzer_noreturn)
+#define SDL_ANALYZER_NORETURN __attribute__((analyzer_noreturn))
+#endif
+#endif
+
+#ifndef SDL_ANALYZER_NORETURN
+#define SDL_ANALYZER_NORETURN
+#endif
+
+/* Apparently this is needed by several Windows compilers */
+#ifndef __MACH__
+#ifndef NULL
+#ifdef __cplusplus
+#define NULL 0
+#else
+#define NULL ((void *)0)
+#endif
+#endif /* NULL */
+#endif /* ! macOS - breaks precompiled headers */
+
+#ifndef SDL_FALLTHROUGH
+#if (defined(__cplusplus) && __cplusplus >= 201703L) || \
+    (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202000L)
+#define SDL_FALLTHROUGH [[fallthrough]]
+#else
+#if defined(__has_attribute) && !defined(__SUNPRO_C) && !defined(__SUNPRO_CC)
+#define SDL_HAS_FALLTHROUGH __has_attribute(__fallthrough__)
+#else
+#define SDL_HAS_FALLTHROUGH 0
+#endif /* __has_attribute */
+#if SDL_HAS_FALLTHROUGH && \
+   ((defined(__GNUC__) && __GNUC__ >= 7) || \
+    (defined(__clang_major__) && __clang_major__ >= 10))
+#define SDL_FALLTHROUGH __attribute__((__fallthrough__))
+#else
+#define SDL_FALLTHROUGH do {} while (0) /* fallthrough */
+#endif /* SDL_HAS_FALLTHROUGH */
+#undef SDL_HAS_FALLTHROUGH
+#endif /* C++17 or C2x */
+#endif /* SDL_FALLTHROUGH not defined */
+
+#ifndef SDL_NODISCARD
+#if (defined(__cplusplus) && __cplusplus >= 201703L) || \
+    (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202311L)
+#define SDL_NODISCARD [[nodiscard]]
+#elif ( (defined(__GNUC__) && (__GNUC__ >= 4)) || defined(__clang__) )
+#define SDL_NODISCARD __attribute__((warn_unused_result))
+#elif defined(_MSC_VER) && (_MSC_VER >= 1700)
+#define SDL_NODISCARD _Check_return_
+#else
+#define SDL_NODISCARD
+#endif /* C++17 or C23 */
+#endif /* SDL_NODISCARD not defined */
+
+#ifndef SDL_MALLOC
+#if defined(__GNUC__) && (__GNUC__ >= 3)
+#define SDL_MALLOC __attribute__((malloc))
+/** FIXME
+#elif defined(_MSC_VER)
+#define SDL_MALLOC __declspec(allocator) __desclspec(restrict)
+**/
+#else
+#define SDL_MALLOC
+#endif
+#endif /* SDL_MALLOC not defined */
+
+#ifndef SDL_ALLOC_SIZE
+#if (defined(__clang__) && __clang_major__ >= 4) || (defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)))
+#define SDL_ALLOC_SIZE(p) __attribute__((alloc_size(p)))
+#elif defined(_MSC_VER)
+#define SDL_ALLOC_SIZE(p)
+#else
+#define SDL_ALLOC_SIZE(p)
+#endif
+#endif /* SDL_ALLOC_SIZE not defined */
+
+#ifndef SDL_ALLOC_SIZE2
+#if (defined(__clang__) && __clang_major__ >= 4) || (defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)))
+#define SDL_ALLOC_SIZE2(p1, p2) __attribute__((alloc_size(p1, p2)))
+#elif defined(_MSC_VER)
+#define SDL_ALLOC_SIZE2(p1, p2)
+#else
+#define SDL_ALLOC_SIZE2(p1, p2)
+#endif
+#endif /* SDL_ALLOC_SIZE2 not defined */
+
+#ifndef SDL_ALIGNED
+#if defined(__clang__) || defined(__GNUC__)
+#define SDL_ALIGNED(x) __attribute__((aligned(x)))
+#elif defined(_MSC_VER)
+#define SDL_ALIGNED(x) __declspec(align(x))
+#elif defined(__cplusplus) && (__cplusplus >= 201103L)
+#define SDL_ALIGNED(x) alignas(x)
+#elif defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
+#define SDL_ALIGNED(x) _Alignas(x)
+#else
+#define SDL_ALIGNED(x) PLEASE_DEFINE_SDL_ALIGNED
+#endif
+#endif /* SDL_ALIGNED not defined */
+