Removed "hack" macro set

git-svn-id: https://svn.code.sf.net/p/freeglut/code/trunk@1825 7f0cb862-5218-0410-a997-914c9d46530a
This commit is contained in:
dcnieho 2017-06-30 23:22:59 +00:00
parent 1fec35a406
commit 47fb7d5f28

View File

@ -34,9 +34,7 @@
*/ */
/* /*
* Compiler defines: * Compiler define: FG_COMPILER_SUPPORTS_VA_ARGS: if the compiler supports variadic macros
* FG_COMPILER_SUPPORTS_GCC_VA_ARGS_HACK: if the compiler supports GCC's variadic macro implementation (AKA, ##__VA_ARGS__)
* FG_COMPILER_SUPPORTS_VA_ARGS: if the compiler supports variadic macros
*/ */
/* What supports variadic macros based off Wikipedia article on it (GCC-like must support C99 or higher to use variadic macros) */ /* What supports variadic macros based off Wikipedia article on it (GCC-like must support C99 or higher to use variadic macros) */
@ -51,15 +49,6 @@
#define FG_COMPILER_SUPPORTS_VA_ARGS 0 #define FG_COMPILER_SUPPORTS_VA_ARGS 0
#endif #endif
/* If __VA_ARGS__ is supported, it needs to be GCC(-like) or Clang (since Clang mimics GCC) */
#if FG_COMPILER_SUPPORTS_VA_ARGS && \
(defined(__GNUC__)) || \
(defined(__clang__))
#define FG_COMPILER_SUPPORTS_GCC_VA_ARGS_HACK 1
#else
#define FG_COMPILER_SUPPORTS_GCC_VA_ARGS_HACK 0
#endif
/* /*
* -------------------------- * --------------------------
* Executing window callbacks * Executing window callbacks
@ -82,86 +71,20 @@
* *
* Onto the different "versions" of macros: * Onto the different "versions" of macros:
* *
* There is one for GCC/Clang(/and supposedly the Intel compiler) which supports the non-standard ##__VA_ARGS__ token. The code may * The first is for any compiler that supports C99 by default. It requires each callback to have a specific argument count
* look ugly, but the result is, if this was standard, no one would ever need to open this file unless they were curious (or needed * passthrough macro. The only reason there are specific count macros is so that (see paraghraph below) don't need have their own
* more then 5 arguments for a callback, but that's trivial to add). It works by adding many fake macros to a "picker" macro * set of callback macros. Ideally, there would only be ZERO and ONE_OR_MORE. This works by having callback-specific macros call a
* (PP_HAS_ARGS_IMPL2) which then indictaes which macro counter to use. As we can already use variadic macros (the VA in __VA_ARGS__), * specific handler macro to return user data (ZERO) or return one or more arguments along with userData (ONE_OR_MORE) where, with
* this just becomes a "reuse the arguments*. * variadic macros, it just reuses the arguments.
* *
* The next is for any non-GCC/Clang/etc. compiler *cough* MSVC/compiler you probably shouldn't be using *cough* that supports C99 * The last macro set is for the poor individual who has to use a compiler that doesn't support C99 by default, or may not support
* by default. It requires each callback to have a specific argument count passthrough macro. The only reason there are specific * it at all. Stuff like MSVC6... It works by having a specific-count macro that "extracts" each argument to have them reused without
* count macros is so that (see paraghraph below) don't need have their own set of callback macros. Ideally, there would only be * the parathesis.
* ZERO and ONE_OR_MORE. This works by having callback-specific macros call a specific handler macro to return user data (ZERO) or
* return one or more arguments along with userData (ONE_OR_MORE) where, with variadic macros, it just reuses the arguments.
* *
* The last set is for the poor individual who has to use a compiler that doesn't support C99 by default, or may not support it at * There is a 3rd macro set that only worked on GCC/Clang, and thus was removed (last seen in revision e9676fc of the GIT mirror.
* all. Stuff like MSVC6... It works by having a specific-count macro that "extracts" each argument to have them reused without the * Not sure at this time what the SVN number is.) as it's a non-standard functionality.
* parathesis.
*
* A note on parathesis, as earlier mentioned, if the GCC variadic macro element was standard, then instead of needing:
*
* func EXPAND_WCB(Mouse)(( (GLUT_LEFT_BUTTON, GLUT_DOWN, 10, 30), userData));
*
* ...you can do the following:
*
* func EXPAND_WCB (GLUT_LEFT_BUTTON, GLUT_DOWN, 10, 30);
*
* Wow... so much nice and easier to understand. Sub-note: I have not worked on a version that explicitly takes userData, so for now
* if you can get to that version, look in the version control change history for this file and you'll find that version which
* implicitly passes "userData" and only works on GCC vardiac macro supporting compilers.
*/ */
#if FG_COMPILER_SUPPORTS_GCC_VA_ARGS_HACK
/*
* EXPAND_WCB() is used as:
*
* EXPAND_WCB( cbname )(( arg_list, userData ))
*
* ... where {(arg_list)} is the parameter list and userData is user
* provided data.
*
* All additional macros are to get around trailing ',' for zero-arg
* callbacks.
*
* Modification of:
* http://stackoverflow.com/questions/5355241/generating-function-declaration-using-a-macro-iteration/5355946#5355946
*
* --------------
*
* GCC-specific design that doesn't require per-callback defines
*
* The naming is terrible... and it's very convuluted and complex, but
* should not require any modification unless additional arguments are to
* be supported.
*
* Supports callbacks up to 5 args (follow the pattern of
* EXPAND_WCB_PP_HAS_ARGS_IMPL2 and EXPAND_WCB_PP_HAS_ARGS_SOURCE to add more)
*
* Edit with care.
*/
#define EXPAND_WCB_UNPARAN(...) __VA_ARGS__
#define EXPAND_WCB_PP_HAS_ARGS_IMPL2(_0, _1, _2, _3, _4, _5, N, ...) N
#define EXPAND_WCB_PP_HAS_ARGS_SOURCE() ONE_OR_MORE, ONE_OR_MORE, ONE_OR_MORE, ONE_OR_MORE, ONE_OR_MORE, ZERO
#define EXPAND_WCB_PP_HAS_ARGS_IMPL(...) EXPAND_WCB_PP_HAS_ARGS_IMPL2( __VA_ARGS__ )
#define EXPAND_WCB_PP_HAS_ARGS(...) EXPAND_WCB_PP_HAS_ARGS_IMPL( NOT_EXIST, ##__VA_ARGS__, EXPAND_WCB_PP_HAS_ARGS_SOURCE() )
#define EXPAND_WCB_ZERO(args, userData) ( userData )
#define EXPAND_WCB_ONE_OR_MORE(args, userData) ( EXPAND_WCB_UNPARAN args, userData )
#define EXPAND_WCB_DISAMBIGUATE2(has_args, args, userData) EXPAND_WCB_ ## has_args ( args, userData )
#define EXPAND_WCB_DISAMBIGUATE(has_args, args, userData) EXPAND_WCB_DISAMBIGUATE2( has_args, args, userData )
#define EXPAND_WCB_UNWRAP_ARGS2(args, userData) EXPAND_WCB_DISAMBIGUATE( EXPAND_WCB_PP_HAS_ARGS args, args, userData )
#define EXPAND_WCB_UNWRAP_ARGS(args) EXPAND_WCB_UNWRAP_ARGS2 args
#define EXPAND_WCB(cbname) EXPAND_WCB_UNWRAP_ARGS
#else
/* /*
* EXPAND_WCB() is used as: * EXPAND_WCB() is used as:
* *
@ -255,8 +178,6 @@
#define EXPAND_WCB_SUB_InitContext(args) EXPAND_WCB_ZERO args #define EXPAND_WCB_SUB_InitContext(args) EXPAND_WCB_ZERO args
#define EXPAND_WCB_SUB_AppStatus(args) EXPAND_WCB_ONE args #define EXPAND_WCB_SUB_AppStatus(args) EXPAND_WCB_ONE args
#endif
/* /*
* ------------------------ * ------------------------
* Setting window callbacks * Setting window callbacks