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.
14 If defined, headers will provide functions fseeko and ftello.
16 If defined, headers will in addition to data types, constants and
17 functions named xxx (e.g. off_t, struct stat, F_SETLK, ftruncate())
18 supply data types, constants and functions named xxx64 (e.g. off64_t,
19 struct stat64, F_SETLK64, ftruncate64()) known as an interface for
22 Defined to 1 and used internally when built with _LARGEFILE[64]_SOURCE.
26 Select default filesystem interface. When defined as 64 the data types,
27 constants and functions mentioned in _LARGEFILE64_SOURCE as xxx are
28 aliased to the corresponding xxx64 data types, constants and functions.
29 _FILE_OFFSET_BITS=64 enables both __USE_LARGEFILE and __USE_LARGEFILE64.
30 This flag does not affect the way libc itself is built, it only affects
31 what declarations are provided to library user.
33 Defined to 1 and used internally when built with _FILE_OFFSET_BITS=64.
37 Function annotation "I do not throw anything".
39 Function annotation "I do not throw anything".
40 Needed for situatuons when it's unclear on what side of "func(params)"
41 the "throw()" or "attribute((nothrow))" should eventually appear.
44 return_type __REDIRECT(name, (params), alias)
45 declare alias to "name(params)"
46 return_type __REDIRECT_NTH(name, (params), alias)
47 declare alias to "name(params) __THROW"
51 Should be always as shown. __PDP_ENDIAN is historic, ignore?
52 __BYTE_ORDER, __FLOAT_WORD_ORDER
53 Should be defined to __BIG_ENDIAN or __LITTLE_ENDIAN.
54 Usage: "#if __BYTE_ORDER == __LITTLE_ENDIAN ..."
55 __USE_BSD adds versions without leading "__" for above four defines.
56 _BIG_ENDIAN, __BIG_ENDIAN__
57 _LITTLE_ENDIAN, __LITTLE_ENDIAN__
58 Defined (to what?) by gcc for some architectures to indicate endianness.
59 Seems that the fact of defined-ness is an indicator, not the value.
62 If defined, headers will supply some function as inlines.
63 uclibc itself is built with this option off and provides
64 out-of-line version of every inlined function in case user program
65 calls it instead of using an inline.
67 If not defined by user prior to #include, will be defined to
68 "extern inline" or equivalent. IOW, if user defines it prior
69 #include, it replaces "extern __inline" string in inline definitions
70 (those enabled by __USE_EXTERN_INLINES) with something else.
71 A few uclibc .c files use it to create non-inlined functions
74 Defined to "extern inline", modulo gcc/C standard deviations.
75 Can't be used by user to play tricks as with _EXTERN_INLINE.
78 Used to modify function's calling convention, if "standard" one
79 is suboptimal. Examples:
80 int func(params) internal_function;
81 int internal_function func(params) { body }
84 Defined only at libc build time. It is physically deleted
85 from the headers (using unifdef tool) in installed headers ("make install").
88 uclibc-internal and uclibc-specific defines. In particular:
89 __UCLIBC_HAS_XXX__, __UCLIBC_HAVE_XXX__
90 __UCLIBC_HAS_XXX__ are booleans (defined/undefined), defined in
91 uClibc_config.h and generated from uclibc .config file.
92 __UCLIBC_HAVE_XXX__ are booleans from bits/uClibc_arch_features.h
93 (there are more __UCLIBC_XXX defines there)
96 Never defined, TODO: remove?
99 All functions, even small ones, have stack smashing protection