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| -rw-r--r-- | doc/info/chap/introduction.texinfo | 63 |
1 files changed, 62 insertions, 1 deletions
diff --git a/doc/info/chap/introduction.texinfo b/doc/info/chap/introduction.texinfo index cb2bfe5..5dcf7cb 100644 --- a/doc/info/chap/introduction.texinfo +++ b/doc/info/chap/introduction.texinfo @@ -179,5 +179,66 @@ unless the header file is included. @node Feature-Test Macros @section Feature-Test Macros -LOREM IPSUM +@cpindex Feature-test macros +@cpindex Enable features +@cpindex Disable features +@cpindex Extensions +The exact set of features that are make available +by @command{slibc}, depend on which feature-test +macros that are defined. + +@command{slibc} specifies four feature-test macros: + +@table @code +@item _PORTABLE_SOURCE +@lvindex _PORTABLE_SOURCE +@cpindex Portability +Disables all non-@sc{POSIX} extensions, and +otherwise help ensure that the source is portable. + +@item _LIBRARY_HEADER +@lvindex _LIBRARY_HEADER +@cpindex Portability +Alternative to @code{_PORTABLE_SOURCE} that should +be used in header files for libraries. This allows +you to be sure that your library is portable between +@code{libc}:s, and that sources using your library +does not been to be compiled with the same @code{libc}. +It is important to use this instead of +@code{_PORTABLE_SOURCE} in library header files, +otherwise the user of the library cannot fully utilise +@code{_PORTABLE_SOURCE}. + +@item _ALL_SOURCE +@lvindex _ALL_SOURCE +@cpindex Portability +Enables all support extensions. +@* TODO: This is not implemented yet. + +@item _SLIBC_SOURCE +@lvindex _SLIBC_SOURCE +Enables extensions added by @command{slibc}, +and extensions added in other @command{libc}:s +that are considered to be good extensions. +@end table + +@cpindex Portability +For programs that are intended to be portable, +it is recommended to develop the software with +@code{_PORTABLE_SOURCE} defined, by adding the +flag @code{-D_PORTABLE_SOURCE} when compiling +the software, to ensure that you are not using +any non-portable extensions. You should also +occasionally compile with the @code{_ALL_SOURCE} +macro defined instead of the @code{_PORTABLE_SOURCE} +defined, to ensure that you do not define names +that may conflict with other @command{libc}:s. + +@cpindex Suppress warnings +@cpindex Warnings, suppress +@lvindex _SLIBC_SUPPRESS_WARNINGS +Additionally, @command{slibc} specifies the +@code{_SLIBC_SUPPRESS_WARNINGS} macro. If this +macro defined, all warnings @command{slibc} +defines for header files and functions are disabled. |