From f0abc6f0061255195880cc281f428f4adcf3b33a Mon Sep 17 00:00:00 2001 From: marha Date: Wed, 28 Apr 2010 15:17:20 +0000 Subject: svn merge -r554:HEAD "^/branches/released" . --- xorg-server/doc/c-extensions | 61 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 xorg-server/doc/c-extensions (limited to 'xorg-server/doc/c-extensions') diff --git a/xorg-server/doc/c-extensions b/xorg-server/doc/c-extensions new file mode 100644 index 000000000..eb33e272b --- /dev/null +++ b/xorg-server/doc/c-extensions @@ -0,0 +1,61 @@ +First of all: C89 or better. If you don't have that, port gcc first. + +Use of C language extensions throughout the X server tree +--------------------------------------------------------- + +Optional extensions: +The server will still build if your toolchain does not support these +extensions, although the results may not be optimal. + + * _X_SENTINEL(x): member x of the passed structure must be NULL, e.g.: + void parseOptions(Option *options _X_SENTINEL(0)); + parseOptions("foo", "bar", NULL); /* this is OK */ + parseOptions("foo", "bar", "baz"); /* this is not */ + This definition comes from Xfuncproto.h in the core + protocol headers. + * _X_ATTRIBUTE_PRINTF(x, y): This function has printf-like semantics; + check the format string when built with + -Wformat (gcc) or similar. + * _X_EXPORT: this function should appear in symbol tables. + * _X_HIDDEN: this function should not appear in the _dynamic_ symbol + table. + * _X_INTERNAL: like _X_HIDDEN, but attempt to ensure that this function + is never called from another module. + * _X_INLINE: inline this functon if possible (generally obeyed unless + disabling optimisations). + * _X_DEPRECATED: warn on use of this function. + +Mandatory extensions: +The server will not build if your toolchain does not support these extensions. + + * named initialisers: explicitly initialising structure members, e.g.: + struct foo bar = { .baz = quux, .brian = "dog" }; + * variadic macros: macros with a variable number of arguments, e.g.: + #define DebugF(x, ...) /**/ + * interleaved code and declarations: { foo = TRUE; int bar; do_stuff(); } + + +Use of OS and library facilities throughout the X server tree +------------------------------------------------------------- + +Non-OS-dependent code can assume facilities at least as good as +the non-OS-facility parts of POSIX-1.2001. Ideally this would +be C99, but even gcc+glibc doesn't implement that yet. + +Unix-like systems are assumed to be at least as good as UNIX03. + +Linux systems must be at least 2.4 or later. As a practical matter +though, 2.4 kernels never receive any testing. Use 2.6 already. + +TODO: Solaris. + +TODO: *BSD. + +Code that needs to be portable to Windows should be careful to, +well, be portable. Note that there are two Windows ports, cygwin and +mingw. Cygwin is more or less like Linux, but mingw is a bit more +restrictive. TODO: document which versions of Windows we actually care +about. + +OSX support is generally limited to the most recent version. Currently +that means 10.5. -- cgit v1.2.3