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diff --git a/doc/info/chap/introduction.texinfo b/doc/info/chap/introduction.texinfo index e846bda..cb2bfe5 100644 --- a/doc/info/chap/introduction.texinfo +++ b/doc/info/chap/introduction.texinfo @@ -4,7 +4,7 @@ @cpindex Hosted environment @cpindex Unhosted environment The C programming language does not provide -an built-in functions or constant values. +any built-in functions or constant values. It only, provides a few basic numerical data types. In fact, it does not even call the function @code{main}. All of these @@ -40,3 +40,144 @@ as a more extensive documentation. It is written with the assumption that you are familiar with the C programming language. + +@menu +* Reserved Names:: Names you should not use for your functions and variables. +* Feature-Test Macros:: Specifying features that should be available. +@end menu + + + +@node Reserved Names +@section Reserved Names + +The names of all types, variables, functions and +macros, that comes from the @sc{ISO}@tie{}C standard +are reserved. Additionally, all names that are +defined or declared from an explicitly included +header file is reserved. + +It is important for maintainability that reserved +names are not redefined. But it is also important +because the C compiler can do special optimisations +bases on the semantics of the standardised function. +It may even replace the function calls, with functions +built into the compiler. + +The names that are reserved is not implemented to +those documented in this manual. Some names are +reserved for future use, for the C standard library +to use internally, and for the compiler to define +to give information about the platform. Names +starting with at least one underscore (`_') are +reserved for the two latter. The names that are +reserved for the C and @sc{POSIX} standards, and the +operating system, are: + +@itemize @bullet{} +@item +Names that begin with an uppercase @code{E} and +a digit or uppercase letter. These are used for +error-codes names. + +@item +Names that begin with @code{LC_} and an uppercase +letter are reserved for locale attributes. + +@item +Names that being with @code{SIG} and an uppercase +letter are reserved for signal names. + +@item +Names that being with @code{SIG_} and an uppercase +letter are reserved for signal actions. + +@item +Names that begin with @code{is} and a lowercase +letter are reserved for character type testing. + +@item +Names that begin with @code{mem} and a lowercase +letter are reserved for functions that operate +over character arrays. + +@item +Names that begin with @code{str} and a lowercase +letter are reserved for functions that operate +over strings. + +@item +Names that begin with @code{to} and a lowercase +letter are reserved for character type conversion. + +@item +Names that begin with @code{wmem} and a lowercase +letter are reserved for functions that operate +over wide-character arrays. + +@item +Names that begin with @code{wcs} and a lowercase +letter are reserved for functions that operate +over wide-character strings. + +@item +Names that end with @code{_t} ae reserved for +type definitions. + +@item +Names of existing mathematics functions, suffixed +with @code{f} or @code{l} are reserved for +@code{float}- and @code{long double}-variants +of corresponding functions. + +@item +Names that begin with @code{d_} are reserved +for @file{<dirent.h>}. + +@item +Names that begin with @code{F_}, @code{O_}, +or @code{l_} are reserved for @file{<fcntl.h>}. + +@item +Names that begin with @code{gr_} are reserved +for @file{<grp.h>}. + +@item +Names that end with @code{_MAX} are reserved +for @file{<limits.h>}. + +@item +Names that begin with @code{pw_} are reserved +for @file{<pwd.h>}. + +@item +Names that begin with @code{sa_} or @code{SA_} +are reserved for @file{<signal.h>}. + +@item +Names that begin with @code{S_} or @code{st_} +are reserved for @file{<sys/stat.h>}. + +@item +Names that begin with @code{tms_} are reserved +for @file{<sys/times.h>}. + +@item +Names that begin with @code{B} and a digit, +@code{I}, @code{O}, @code{TB}, @code{V}, or +@code{c_} are reserved for @file{<termios.h>}. +@end itemize + +It is possible for libraries to avoid restrictions +by prefixing all names with the name of the library +(starting with @code{lib}.) Names that are reserved +for specific header files do not need to considered +unless the header file is included. + + + +@node Feature-Test Macros +@section Feature-Test Macros + +LOREM IPSUM + |