1 Feeble attempt to document the horde of #defines we deal with.
2 Editors, plese 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.
21 __REDIRECT(name, proto, alias)
22 __REDIRECT_NTH(name, proto, alias)
27 Should be always as shown. __PDP_ENDIAN is historic, ignore?
28 __BYTE_ORDER, __FLOAT_WORD_ORDER
29 Should be defined to __BIG_ENDIAN or __LITTLE_ENDIAN.
30 Usage: "#if __BYTE_ORDER == __LITTLE_ENDIAN ..."
31 __USE_BSD adds versions without leading "__" for above four defines.
32 _BIG_ENDIAN, __BIG_ENDIAN__
33 _LITTLE_ENDIAN, __LITTLE_ENDIAN__
34 Defined (to what?) by gcc for some architectures to indicate endianness.
35 Seems that the fact of defined-ness is an indicator, not the value.
38 If defined, headers will supply some function as inlines.
39 uclibc itself is built with this option off and provides
40 out-of-line version of every inlined function in case user program
41 calls it instead of using an inline.
43 If not defined by user prior to #include, will be defined to
44 "extern inline" or equivalent. IOW, if user defines it prior
45 #include, it replaces "extern __inline" string in inline definitions
46 (those enabled by __USE_EXTERN_INLINES) with something else.
47 A few uclibc .c files use it to create non-inlined functions
50 Defined to "extern inline", modulo gcc/C standard deviations.
51 Can't be used by user to play tricks as with _EXTERN_INLINE.
53 Used to modify function's calling convention, if "standard" one
54 is suboptimal. Examples:
55 int func(params) internal_function;
56 int internal_function func(params) { body }
60 Defined only at libc build time. _LIBC is probably from glibc,
61 and UCLIBC_INTERNAL is added by vda (he didn't know about _LIBC).
62 Both defines are physically deleted from headers (using unifdef tool)
63 in installed headers ("make install").
66 uclibc-internal and uclibc-specific defines. In particular:
67 __UCLIBC_HAS_XXX__, __UCLIBC_HAVE_XXX__
68 __UCLIBC_HAS_XXX__ are booleans (defined/undefined), defined in
69 uClibc_config.h and generated from uclibc .config file.
70 __UCLIBC_HAVE_XXX__ are booleans from bits/uClibc_arch_features.h
71 (there are more __UCLIBC_XXX defines there)