1 Feeble attempt to document the horde of #defines we deal with.
2 Editors, please make your descriptions short but informative.
6 __BEGIN_DECLS, __END_DECLS
7 Defined to either empty or 'extern "C" {' and '}' if included by C++.
9 __USE_GNU, __USE_BSD, __USE_XOPEN[2K], __USE_SVID, __USE_POSIX...
10 If defined, user program which included us requests compat additions
11 from relevant standard or Unix flavor. See features.h for full list.
20 Function annotation "I do not throw anything".
22 Function annotation "I do not throw anything".
23 Needed for situatuons when it's unclear on what side of "func(params)"
24 the "throw()" or "attribute((nothrow))" should eventually appear.
27 return_type __REDIRECT(name, (params), alias)
28 declare alias to "name(params)"
29 return_type __REDIRECT_NTH(name, (params), alias)
30 declare alias to "name(params) __THROW"
34 Should be always as shown. __PDP_ENDIAN is historic, ignore?
35 __BYTE_ORDER, __FLOAT_WORD_ORDER
36 Should be defined to __BIG_ENDIAN or __LITTLE_ENDIAN.
37 Usage: "#if __BYTE_ORDER == __LITTLE_ENDIAN ..."
38 __USE_BSD adds versions without leading "__" for above four defines.
39 _BIG_ENDIAN, __BIG_ENDIAN__
40 _LITTLE_ENDIAN, __LITTLE_ENDIAN__
41 Defined (to what?) by gcc for some architectures to indicate endianness.
42 Seems that the fact of defined-ness is an indicator, not the value.
45 If defined, headers will supply some function as inlines.
46 uclibc itself is built with this option off and provides
47 out-of-line version of every inlined function in case user program
48 calls it instead of using an inline.
50 If not defined by user prior to #include, will be defined to
51 "extern inline" or equivalent. IOW, if user defines it prior
52 #include, it replaces "extern __inline" string in inline definitions
53 (those enabled by __USE_EXTERN_INLINES) with something else.
54 A few uclibc .c files use it to create non-inlined functions
57 Defined to "extern inline", modulo gcc/C standard deviations.
58 Can't be used by user to play tricks as with _EXTERN_INLINE.
61 Used to modify function's calling convention, if "standard" one
62 is suboptimal. Examples:
63 int func(params) internal_function;
64 int internal_function func(params) { body }
67 Defined only at libc build time. It is physically deleted
68 from the headers (using unifdef tool) in installed headers ("make install").
71 uclibc-internal and uclibc-specific defines. In particular:
72 __UCLIBC_HAS_XXX__, __UCLIBC_HAVE_XXX__
73 __UCLIBC_HAS_XXX__ are booleans (defined/undefined), defined in
74 uClibc_config.h and generated from uclibc .config file.
75 __UCLIBC_HAVE_XXX__ are booleans from bits/uClibc_arch_features.h
76 (there are more __UCLIBC_XXX defines there)
79 Never defined, TODO: remove?
82 All functions, even small ones, have stack smashing protection