@setfilename ../info/standards.info
@settitle GNU Coding Standards
@c This date is automagically updated when you save this file:
-@set lastupdate June 24, 1999
+@set lastupdate February 21, 2001
@c %**end of header
@ifinfo
@c @setchapternewpage odd
@setchapternewpage off
+@c Put everything in one index (arbitrarily chosen to be the concept index).
+@syncodeindex fn cp
+@syncodeindex ky cp
+@syncodeindex pg cp
+@syncodeindex vr cp
+
@c This is used by a cross ref in make-stds.texi
@set CODESTD 1
@iftex
@ifinfo
GNU Coding Standards
-Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
+Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
@page
@vskip 0pt plus 1filll
-Copyright @copyright{} 1992, 1993, 1994, 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
+Copyright @copyright{} 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
* Documentation:: Documenting Programs
* Managing Releases:: The Release Process
* References:: References to Non-Free Software or Documentation
+* Index::
@end menu
@node Preface
state reasons for writing in a certain way.
Corrections or suggestions for this document should be sent to
-@email{gnu@@gnu.org}. If you make a suggestion, please include a
+@email{bug-standards@@gnu.org}. If you make a suggestion, please include a
suggested new wording for it; our time is limited. We prefer a context
diff to the @file{standards.texi} or @file{make-stds.texi} files, but if
you don't have those files, please mail your suggestion anyway.
This release of the GNU Coding Standards was last updated
@value{lastupdate}.
+@cindex where to obtain @code{standards.texi}
+@cindex downloading this manual
+If you did not obtain this file directly from the GNU project and
+recently, please check for a newer version. You can ftp the GNU Coding
+Standards from any GNU FTP host in the directory
+@file{/pub/gnu/standards/}. The GNU Coding Standards are available
+there in several different formats: @file{standards.text},
+@file{standards.texi}, @file{standards.info}, and @file{standards.dvi}.
+The GNU Coding Standards are also available on the GNU World Wide Web
+server: @uref{http://www.gnu.org/prep/standards_toc.html}.
+
@node Legal Issues
@chapter Keeping Free Software Free
+@cindex legal aspects
This @value{CHAPTER} discusses how you can make sure that GNU software
-remains unencumbered.
+avoids legal difficulties, and other related issues.
@menu
* Reading Non-Free Code:: Referring to Proprietary Programs
* Contributions:: Accepting Contributions
+* Trademarks:: How We Deal with Trademark Issues
@end menu
@node Reading Non-Free Code
@section Referring to Proprietary Programs
+@cindex proprietary programs
+@cindex avoiding proprietary code
Don't in any circumstances refer to Unix source code for or during
your work on GNU! (Or to any other proprietary programs.)
Or use a simple garbage collector instead of tracking precisely when
to free memory, or use a new GNU facility such as obstacks.
-
@node Contributions
@section Accepting Contributions
+@cindex legal papers
+@cindex accepting contributions
If the program you are working on is copyrighted by the Free Software
Foundation, then when someone else sends you a piece of code to add to
reached the stage of actually maintaining a program for GNU (whether
released or not), please ask us for a copy.
+@node Trademarks
+@section Trademarks
+@cindex trademarks
+
+Please do not include any trademark acknowledgements in GNU software
+packages or documentation.
+
+Trademark acknowledgements are the statements that such-and-such is a
+trademark of so-and-so. The GNU Project has no objection to the basic
+idea of trademarks, but these acknowledgements feel like kowtowing, so
+we don't use them. There is no legal requirement for them.
+
+What is legally required, as regards other people's trademarks, is to
+avoid using them in ways which a reader might read as naming or labeling
+our own programs or activities. For example, since ``Objective C'' is
+(or at least was) a trademark, we made sure to say that we provide a
+``compiler for the Objective C language'' rather than an ``Objective C
+compiler''. The latter is meant to be short for the former, but it does
+not explicitly state the relationship, so it could be misinterpreted as
+using ``Objective C'' as a label for the compiler rather than for the
+language.
+
@node Design Advice
@chapter General Program Design
+@cindex program design
This @value{CHAPTER} discusses some of the issues you should take into
account when designing your program.
+@c Standard or ANSI C
+@c
+@c In 1989 the American National Standards Institute (ANSI) standardized
+@c C as standard X3.159-1989. In December of that year the
+@c International Standards Organization ISO adopted the ANSI C standard
+@c making minor changes. In 1990 ANSI then re-adopted ISO standard
+@c C. This version of C is known as either ANSI C or Standard C.
+
+@c A major revision of the C Standard appeared in 1999.
+
@menu
+* Source Language:: Which languges to use.
* Compatibility:: Compatibility with other implementations
* Using Extensions:: Using non-standard features
-* ANSI C:: Using ANSI C features
-* Source Language:: Using languages other than C
+* Standard C:: Using Standard C features
@end menu
+@node Source Language
+@section Which Languages to Use
+@cindex programming languges
+
+When you want to use a language that gets compiled and runs at high
+speed, the best language to use is C. Using another language is like
+using a non-standard feature: it will cause trouble for users. Even if
+GCC supports the other language, users may find it inconvenient to have
+to install the compiler for that other language in order to build your
+program. For example, if you write your program in C++, people will
+have to install the GNU C++ compiler in order to compile your program.
+
+C has one other advantage over C++ and other compiled languages: more
+people know C, so more people will find it easy to read and modify the
+program if it is written in C.
+
+So in general it is much better to use C, rather than the
+comparable alternatives.
+
+But there are two exceptions to that conclusion:
+
+@itemize @bullet
+@item
+It is no problem to use another language to write a tool specifically
+intended for use with that language. That is because the only people
+who want to build the tool will be those who have installed the other
+language anyway.
+
+@item
+If an application is of interest only to a narrow part of the community,
+then the question of which language it is written in has less effect on
+other people, so you may as well please yourself.
+@end itemize
+
+Many programs are designed to be extensible: they include an interpreter
+for a language that is higher level than C. Often much of the program
+is written in that language, too. The Emacs editor pioneered this
+technique.
+
+@cindex GUILE
+The standard extensibility interpreter for GNU software is GUILE, which
+implements the language Scheme (an especially clean and simple dialect
+of Lisp). @uref{http://www.gnu.org/software/guile/}. We don't reject
+programs written in other ``scripting languages'' such as Perl and
+Python, but using GUILE is very important for the overall consistency of
+the GNU system.
+
@node Compatibility
@section Compatibility with Other Implementations
+@cindex compatibility with C and @sc{posix} standards
+@cindex @sc{posix} compatibility
With occasional exceptions, utility programs and libraries for GNU
should be upward compatible with those in Berkeley Unix, and upward
-compatible with @sc{ansi} C if @sc{ansi} C specifies their behavior, and
-upward compatible with @sc{posix} if @sc{posix} specifies their
-behavior.
+compatible with Standard C if Standard C specifies their
+behavior, and upward compatible with @sc{posix} if @sc{posix} specifies
+their behavior.
When these standards conflict, it is useful to offer compatibility
modes for each of them.
-@sc{ansi} C and @sc{posix} prohibit many kinds of extensions. Feel free
-to make the extensions anyway, and include a @samp{--ansi},
+@cindex options for compatibility
+Standard C and @sc{posix} prohibit many kinds of extensions. Feel
+free to make the extensions anyway, and include a @samp{--ansi},
@samp{--posix}, or @samp{--compatible} option to turn them off.
However, if the extension has a significant chance of breaking any real
-programs or scripts, then it is not really upward compatible. Try to
-redesign its interface.
+programs or scripts, then it is not really upward compatible. So you
+should try to redesign its interface to make it upward compatible.
+@cindex @code{POSIXLY_CORRECT}, environment variable
Many GNU programs suppress extensions that conflict with @sc{posix} if the
environment variable @code{POSIXLY_CORRECT} is defined (even if it is
defined with a null value). Please make your program recognize this
@code{vi} is replaced with Emacs.) But it is nice to offer a compatible
feature as well. (There is a free @code{vi} clone, so we offer it.)
-Additional useful features not in Berkeley Unix are welcome.
+Additional useful features are welcome regardless of whether
+there is any precedent for them.
@node Using Extensions
@section Using Non-standard Features
+@cindex non-standard extensions
Many GNU facilities that already exist support a number of convenient
extensions over the comparable Unix facilities. Whether to use these
are a big improvement.
An exception to this rule are the large, established programs (such as
-Emacs) which run on a great variety of systems. Such programs would
-be broken by use of GNU extensions.
+Emacs) which run on a great variety of systems. Using GNU extensions in
+such programs would make many users unhappy, so we don't do that.
-Another exception is for programs that are used as part of
-compilation: anything that must be compiled with other compilers in
-order to bootstrap the GNU compilation facilities. If these require
-the GNU compiler, then no one can compile them without having them
-installed already. That would be no good.
+Another exception is for programs that are used as part of compilation:
+anything that must be compiled with other compilers in order to
+bootstrap the GNU compilation facilities. If these require the GNU
+compiler, then no one can compile them without having them installed
+already. That would be extremely troublesome in certain cases.
-@node ANSI C
-@section @sc{ansi} C and pre-@sc{ansi} C
+@node Standard C
+@section Standard C and Pre-Standard C
+@cindex @sc{ansi} C standard
-Do not ever use the ``trigraph'' feature of @sc{ansi} C.
+1989 Standard C is widespread enough now that it is ok to use its
+features in new programs. There is one exception: do not ever use the
+``trigraph'' feature of Standard C.
-@sc{ansi} C is widespread enough now that it is ok to write new programs
-that use @sc{ansi} C features (and therefore will not work in
-non-@sc{ansi} compilers). And if a program is already written in
-@sc{ansi} C, there's no need to convert it to support non-@sc{ansi}
-compilers.
+1999 Standard C is not widespread yet, so please do not require its
+features in programs. It is ok to use its features if they are present.
-If you don't know non-@sc{ansi} C, there's no need to learn it; just
-write in @sc{ansi} C.
+However, it is easy to support pre-standard compilers in most programs,
+so if you know how to do that, feel free. If a program you are
+maintaining has such support, you should try to keep it working.
-However, it is easy to support non-@sc{ansi} compilers in most programs,
-so you might still consider doing so when you write a program. And if a
-program you are maintaining has such support, you should try to keep it
-working.
-
-To support pre-@sc{ansi} C, instead of writing function definitions in
-@sc{ansi} prototype form,
+@cindex function prototypes
+To support pre-standard C, instead of writing function definitions in
+standard prototype form,
@example
int
@end example
@noindent
-write the definition in pre-@sc{ansi} style like this,
+write the definition in pre-standard style like this,
@example
int
@end example
You need such a declaration anyway, in a header file, to get the benefit
-of @sc{ansi} C prototypes in all the files where the function is called.
-And once you have the declaration, you normally lose nothing by writing
-the function definition in the pre-@sc{ansi} style.
+of prototypes in all the files where the function is called. And once
+you have the declaration, you normally lose nothing by writing the
+function definition in the pre-standard style.
This technique does not work for integer types narrower than @code{int}.
If you think of an argument as being of a type narrower than @code{int},
@code{dev_t}, you run into trouble, because @code{dev_t} is shorter than
@code{int} on some machines; but you cannot use @code{int} instead,
because @code{dev_t} is wider than @code{int} on some machines. There
-is no type you can safely use on all machines in a non-@sc{ansi}
-definition. The only way to support non-@sc{ansi} C and pass such an
+is no type you can safely use on all machines in a non-standard
+definition. The only way to support non-standard C and pass such an
argument is to check the width of @code{dev_t} using Autoconf and choose
the argument type accordingly. This may not be worth the trouble.
-@node Source Language
-@section Using Languages Other Than C
-
-Using a language other than C is like using a non-standard feature: it
-will cause trouble for users. Even if GCC supports the other language,
-users may find it inconvenient to have to install the compiler for that
-other language in order to build your program. For example, if you
-write your program in C++, people will have to install the C++ compiler
-in order to compile your program. Thus, it is better if you write in C.
+In order to support pre-standard compilers that do not recognize
+prototypes, you may want to use a preprocessor macro like this:
-But there are three situations when there is no disadvantage in using
-some other language:
-
-@itemize @bullet
-@item
-It is okay to use another language if your program contains an
-interpreter for that language.
-
-For example, if your program links with GUILE, it is ok to write part of
-the program in Scheme or another language supported by GUILE.
-
-@item
-It is okay to use another language in a tool specifically intended for
-use with that language.
-
-This is okay because the only people who want to build the tool will be
-those who have installed the other language anyway.
-
-@item
-If an application is of interest to a narrow community, then perhaps
-it's not important if the application is inconvenient to install.
-@end itemize
-
-C has one other advantage over C++ and other compiled languages: more
-people know C, so more people will find it easy to read and modify the
-program if it is written in C.
+@example
+/* Declare the prototype for a general external function. */
+#if defined (__STDC__) || defined (WINDOWSNT)
+#define P_(proto) proto
+#else
+#define P_(proto) ()
+#endif
+@end example
@node Program Behavior
@chapter Program Behavior for All Programs
-This @value{CHAPTER} describes how to write robust software. It also
-describes general standards for error messages, the command line interface,
-and how libraries should behave.
+This @value{CHAPTER} describes conventions for writing robust
+software. It also describes general standards for error messages, the
+command line interface, and how libraries should behave.
@menu
* Semantics:: Writing robust programs
* Libraries:: Library behavior
* Errors:: Formatting error messages
-* User Interfaces:: Standards for command line interfaces
-* Option Table:: Table of long options.
+* User Interfaces:: Standards about interfaces generally
+* Graphical Interfaces:: Standards for graphical interfaces
+* Command-Line Interfaces:: Standards for command line interfaces
+* Option Table:: Table of long options
* Memory Usage:: When and how to care about memory needs
+* File Usage:: Which files to use, and where
@end menu
@node Semantics
@section Writing Robust Programs
+@cindex arbitrary limits on data
Avoid arbitrary limits on the length or number of @emph{any} data
structure, including file names, lines, files, and symbols, by allocating
all data structures dynamically. In most Unix utilities, ``long lines
are silently truncated''. This is not acceptable in a GNU utility.
+@cindex @code{NUL} characters
Utilities reading files should not drop NUL characters, or any other
nonprinting characters @emph{including those with codes above 0177}.
The only sensible exceptions would be utilities specifically intended
sequences of bytes that represent multibyte characters, using encodings
such as UTF-8 and others.
+@cindex error messages
Check every system call for an error return, unless you know you wish to
ignore errors. Include the system error text (from @code{perror} or
equivalent) in @emph{every} error message resulting from a failing
utility. Just ``cannot open foo.c'' or ``stat failed'' is not
sufficient.
+@cindex @code{malloc} return value
+@cindex memory allocation failure
Check every call to @code{malloc} or @code{realloc} to see if it
returned zero. Check @code{realloc} even if you are making the block
smaller; in a system that rounds block sizes to a power of 2,
reader loop. This allows the user to kill other processes to free up
virtual memory, and then try the command again.
+@cindex command-line arguments, decoding
Use @code{getopt_long} to decode arguments, unless the argument syntax
makes this unreasonable.
in a directory, use @code{readdir} or some other high-level interface.
These are supported compatibly by GNU.
+@cindex signal handling
The preferred signal handling facilities are the BSD variant of
@code{signal}, and the @sc{posix} @code{sigaction} function; the
alternative USG @code{signal} interface is an inferior design.
behavior. It is up to you whether to support systems where
@code{signal} has only the USG behavior, or give up on them.
+@cindex impossible conditions
In error checks that detect ``impossible'' conditions, just abort.
There is usually no point in printing any message. These checks
indicate the existence of bugs. Whoever wants to fix the bugs will have
errors; if you try to return 256 as the exit status, the parent process
will see 0 as the status, and it will appear that the program succeeded.
+@cindex temporary files
+@cindex @code{TMPDIR} environment variable
If you make temporary files, check the @code{TMPDIR} environment
variable; if that variable is defined, use the specified directory
instead of @file{/tmp}.
+In addition, be aware that there is a possible security problem when
+creating temporary files in world-writable directories. In C, you can
+avoid this problem by creating temporary files in this manner:
+
+@example
+fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0600);
+@end example
+
+@noindent
+or by using the @code{mkstemps} function from libiberty.
+
+In bash, use @code{set -C} to avoid this problem.
+
@node Libraries
@section Library Behavior
+@cindex libraries
Try to make library functions reentrant. If they need to do dynamic
storage allocation, at least try to avoid any nonreentrancy aside from
other; then they can both go in the same file.
External symbols that are not documented entry points for the user
-should have names beginning with @samp{_}. They should also contain
-the chosen name prefix for the library, to prevent collisions with
-other libraries. These can go in the same files with user entry
-points if you like.
+should have names beginning with @samp{_}. The @samp{_} should be
+followed by the chosen name prefix for the library, to prevent
+collisions with other libraries. These can go in the same files with
+user entry points if you like.
Static functions and variables can be used as you like and need not
fit any naming convention.
@node Errors
@section Formatting Error Messages
+@cindex formatting error messages
+@cindex error messages, formatting
Error messages from compilers should look like this:
end with a period.
@node User Interfaces
-@section Standards for Command Line Interfaces
+@section Standards for Interfaces Generally
+@cindex program name and its behavior
+@cindex behavior, dependent on program's name
Please don't make the behavior of a utility depend on the name used
to invoke it. It is useful sometimes to make a link to a utility
with a different name, and that should not change what it does.
Instead, use a run time option or a compilation switch or both
to select among the alternate behaviors.
+@cindex output device and program's behavior
Likewise, please don't make the behavior of the program depend on the
type of output device it is used with. Device independence is an
important principle of the system's design; do not compromise it merely
like @code{ls} except that its default output format is always
multi-column format.
+@node Graphical Interfaces
+@section Standards for Graphical Interfaces
+@cindex graphical user interface
+
+@cindex gtk
+When you write a program that provides a graphical user interface,
+please make it work with X Windows and the GTK toolkit unless the
+functionality specifically requires some alternative (for example,
+``displaying jpeg images while in console mode'').
+
+In addition, please provide a command-line interface to control the
+functionality. (In many cases, the graphical user interface can be a
+separate program which invokes the command-line program.) This is
+so that the same jobs can be done from scripts.
+
+@cindex corba
+@cindex gnome
+Please also consider providing a CORBA interface (for use from GNOME), a
+library interface (for use from C), and perhaps a keyboard-driven
+console interface (for use by users from console mode). Once you are
+doing the work to provide the functionality and the graphical interface,
+these won't be much extra work.
+
+@node Command-Line Interfaces
+@section Standards for Command Line Interfaces
+@cindex command-line interface
+
+@findex getopt
It is a good idea to follow the @sc{posix} guidelines for the
command-line options of a program. The easiest way to do this is to use
@code{getopt} to parse them. Note that the GNU version of @code{getopt}
special argument @samp{--} is used. This is not what @sc{posix}
specifies; it is a GNU extension.
+@cindex long-named options
Please define long-named options that are equivalent to the
single-letter Unix-style options. We hope to make GNU more user
friendly this way. This is easy to do with the GNU function
option as another way to specify it. This will lead to more consistency
among GNU utilities, and fewer idiosyncracies for users to remember.
+@cindex standard command-line options
All programs should support two standard options: @samp{--version}
and @samp{--help}.
@table @code
+@cindex @samp{--version} option
@item --version
This option should direct the program to print information about its name,
version, origin and legal status, all on standard output, and then exit
successfully. Other options and arguments should be ignored once this
is seen, and the program should not perform its normal function.
+@cindex canonical name of a program
+@cindex program's canonical name
The first line is meant to be easy for a program to parse; the version
number proper starts after the last space. In addition, it contains
the canonical name for this program, in this format:
these notices, if that is inconvenient, since it appeared in the first
line.
+@cindex @samp{--help} option
@item --help
This option should output brief documentation for how to invoke the
program, on standard output, then exit successfully. Other options and
arguments should be ignored once this is seen, and the program should
not perform its normal function.
+@cindex address for bug reports
+@cindex bug reports
Near the end of the @samp{--help} option's output there should be a line
that says where to mail bug reports. It should have this format:
@node Option Table
@section Table of Long Options
+@cindex long option names
+@cindex table of long options
Here is a table of long options used by GNU programs. It is surely
incomplete, but we aim to list all the options that a new program might
want to be compatible with. If you use names not already in the table,
-please send @email{gnu@@gnu.org} a list of them, with their
+please send @email{bug-standards@@gnu.org} a list of them, with their
meanings, so we can update the table.
@c Please leave newlines between items in this table; it's much easier
@item hide-control-chars
@samp{-q} in @code{ls}.
+@item html
+In @code{makeinfo}, output HTML.
+
@item idle
@samp{-u} in @code{who}.
@item info
@samp{-i}, @samp{-l}, and @samp{-m} in Finger.
+@item init-file
+In some programs, specify the name of the file to read as the user's
+init file.
+
@item initial
@samp{-i} in @code{expand}.
@item intermix-type
@samp{-p} in @code{shar}.
+@item iso-8601
+Used in @code{date}
+
@item jobs
@samp{-j} in Make.
@node Memory Usage
@section Memory Usage
+@cindex memory usage
-If it typically uses just a few meg of memory, don't bother making any
+If a program typically uses just a few meg of memory, don't bother making any
effort to reduce memory usage. For example, if it is impractical for
other reasons to operate on files more than a few meg long, it is
reasonable to read entire input files into core to operate on them.
If your program creates complicated data structures, just make them in
core and give a fatal error if @code{malloc} returns zero.
+@node File Usage
+@section File Usage
+@cindex file usage
+
+Programs should be prepared to operate when @file{/usr} and @file{/etc}
+are read-only file systems. Thus, if the program manages log files,
+lock files, backup files, score files, or any other files which are
+modified for internal purposes, these files should not be stored in
+@file{/usr} or @file{/etc}.
+
+There are two exceptions. @file{/etc} is used to store system
+configuration information; it is reasonable for a program to modify
+files in @file{/etc} when its job is to update the system configuration.
+Also, if the user explicitly asks to modify one file in a directory, it
+is reasonable for the program to store other files in the same
+directory.
+
@node Writing C
@chapter Making The Best Use of C
@node Formatting
@section Formatting Your Source Code
+@cindex formatting source code
+@cindex open brace
+@cindex braces, in C source
It is important to put the open-brace that starts the body of a C
function in column zero, and avoid putting any other open-brace or
open-parenthesis or open-bracket in column zero. Several tools look
@end example
@noindent
-or, if you want to use @sc{ansi} C, format the definition like this:
+or, if you want to use Standard C syntax, format the definition like
+this:
@example
static char *
@}
@end example
-In @sc{ansi} C, if the arguments don't fit nicely on one line,
+In Standard C, if the arguments don't fit nicely on one line,
split it like this:
@example
@dots{}
@end example
-For the body of the function, we prefer code formatted like this:
+The rest of this section gives our recommendations for other aspects of
+C formatting style, which is also the default style of the @code{indent}
+program in version 1.2 and newer. It corresponds to the options
+
+@smallexample
+-nbad -bap -nbc -bbo -bl -bli2 -bls -ncdb -nce -cp1 -cs -di2
+-ndj -nfc1 -nfca -hnl -i2 -ip5 -lp -pcs -psl -nsc -nsob
+@end smallexample
+
+We don't think of these recommendations as requirements, because it
+causes no problems for users if two different programs have different
+formatting styles.
+
+But whatever style you use, please use it consistently, since a mixture
+of styles within one program tends to look ugly. If you are
+contributing changes to an existing program, please follow the style of
+that program.
+
+For the body of the function, our recommended style looks like this:
@example
if (x < foo (y, z))
@}
@end example
+@cindex spaces before open-paren
We find it easier to read a program when it has spaces before the
open-parentheses and after the commas. Especially after the commas.
When you split an expression into multiple lines, split it
before an operator, not after one. Here is the right way:
+@cindex expressions, splitting
@example
if (foo_this_is_long && bar > win (x, y, z)
&& remaining_condition)
Insert extra parentheses so that Emacs will indent the code properly.
For example, the following indentation looks nice if you do it by hand,
-but Emacs would mess it up:
@example
v = rup->ru_utime.tv_sec*1000 + rup->ru_utime.tv_usec/1000
+ rup->ru_stime.tv_sec*1000 + rup->ru_stime.tv_usec/1000;
@end example
-But adding a set of parentheses solves the problem:
+@noindent
+but Emacs would alter it. Adding a set of parentheses produces
+something that looks equally nice, and which Emacs will preserve:
@example
v = (rup->ru_utime.tv_sec*1000 + rup->ru_utime.tv_usec/1000
while (a > 0);
@end example
+@cindex formfeed
+@cindex control-L
Please use formfeed characters (control-L) to divide the program into
pages at logical places (but not within a function). It does not matter
just how long the pages are, since they do not have to fit on a printed
page. The formfeeds should appear alone on lines by themselves.
-
@node Comments
@section Commenting Your Work
+@cindex commenting
Every program should start with a comment saying briefly what it is for.
Example: @samp{fmt - filter for simple filling of text}.
int truncate_lines;
@end example
+@cindex conditionals, comments for
+@cindex @code{#endif}, commenting
Every @samp{#endif} should have a comment, except in the case of short
conditionals (just a few lines) that are not nested. The comment should
state the condition of the conditional that is ending, @emph{including
@node Syntactic Conventions
@section Clean Use of C Constructs
-
-Please explicitly declare all arguments to functions.
-Don't omit them just because they are @code{int}s.
+@cindex syntactic conventions
+
+@cindex implicit @code{int}
+@cindex function argument, declaring
+Please explicitly declare the types of all objects. For example, you
+should explicitly declare all arguments to functions, and you should
+declare functions to return @code{int} rather than omitting the
+@code{int}.
+
+@cindex compiler warnings
+@cindex @samp{-Wall} compiler option
+Some programmers like to use the GCC @samp{-Wall} option, and change the
+code whenever it issues a warning. If you want to do this, then do.
+Other programmers prefer not to use @samp{-Wall}, because it gives
+warnings for valid and legitimate code which they do not want to change.
+If you want to do this, then do. The compiler should be your servant,
+not your master.
Declarations of external functions and functions to appear later in the
source file should all go in one place near the beginning of the file
should go in a header file. Don't put @code{extern} declarations inside
functions.
+@cindex temporary variables
It used to be common practice to use the same local variables (with
names like @code{tem}) over and over for different values within one
function. Instead of doing this, it is better declare a separate local
Don't use local variables or parameters that shadow global identifiers.
+@cindex multiple variables in a line
Don't declare multiple variables in one declaration that spans lines.
Start a new declaration on each line, instead. For example, instead
of this:
fatal ("virtual memory exhausted");
@end example
+@pindex lint
Don't make the program ugly to placate @code{lint}. Please don't insert any
casts to @code{void}. Zero without a cast is perfectly fine as a null
pointer constant, except when calling a varargs function.
@node Names
@section Naming Variables and Functions
+@cindex names of variables and functions
The names of global variables and functions in a program serve as
comments of a sort. So don't choose terse names---instead, look for
names that give useful information about the meaning of the variable or
@code{enum} rather than @samp{#define}. GDB knows about enumeration
constants.
-Use file names of 14 characters or less, to avoid creating gratuitous
-problems on older System V systems. You can use the program
-@code{doschk} to test for this. @code{doschk} also tests for potential
-name conflicts if the files were loaded onto an MS-DOS file
-system---something you may or may not care about.
+@cindex file-name limitations
+@pindex doschk
+You might want to make sure that none of the file names would conflict
+the files were loaded onto an MS-DOS file system which shortens the
+names. You can use the program @code{doschk} to test for this.
+
+Some GNU programs were designed to limit themselves to file names of 14
+characters or less, to avoid file name conflicts if they are read into
+older System V systems. Please preserve this feature in the existing
+GNU programs that have it, but there is no need to do this in new GNU
+programs. @code{doschk} also reports file names longer than 14
+characters.
@node System Portability
@section Portability between System Types
+@cindex portability, between system types
In the Unix world, ``portability'' refers to porting to different Unix
versions. For a GNU program, this kind of portability is desirable, but
not paramount.
The primary purpose of GNU software is to run on top of the GNU kernel,
-compiled with the GNU C compiler, on various types of @sc{cpu}. The
-amount and kinds of variation among GNU systems on different @sc{cpu}s
-will be comparable to the variation among Linux-based GNU systems or
-among BSD systems today. So the kinds of portability that are absolutely
-necessary are quite limited.
-
-But many users do run GNU software on non-GNU Unix or Unix-like systems.
-So supporting a variety of Unix-like systems is desirable, although not
-paramount.
-
+compiled with the GNU C compiler, on various types of @sc{cpu}. So the
+kinds of portability that are absolutely necessary are quite limited.
+But it is important to support Linux-based GNU systems, since they
+are the form of GNU that is popular.
+
+Beyond that, it is good to support the other free operating systems
+(*BSD), and it is nice to support other Unix-like systems if you want
+to. Supporting a variety of Unix-like systems is desirable, although
+not paramount. It is usually not too hard, so you may as well do it.
+But you don't have to consider it an obligation, if it does turn out to
+be hard.
+
+@pindex autoconf
The easiest way to achieve portability to most Unix-like systems is to
use Autoconf. It's unlikely that your program needs to know more
information about the host platform than Autoconf can provide, simply
Avoid using the format of semi-internal data bases (e.g., directories)
when there is a higher-level alternative (@code{readdir}).
+@cindex non-@sc{posix} systems, and portability
As for systems that are not like Unix, such as MSDOS, Windows, the
Macintosh, VMS, and MVS, supporting them is often a lot of work. When
that is the case, it is better to spend your time adding features that
will be useful on GNU and GNU/Linux, rather than on supporting other
incompatible systems.
+It is a good idea to define the ``feature test macro''
+@code{_GNU_SOURCE} when compiling your C files. When you compile on GNU
+or GNU/Linux, this will enable the declarations of GNU library extension
+functions, and that will usually give you a compiler error message if
+you define the same function names in some other way in your program.
+(You don't have to actually @emph{use} these functions, if you prefer
+to make the program more portable to other systems.)
+
+But whether or not you use these GNU extensions, you should avoid
+using their names for any other meanings. Doing so would make it hard
+to move your code into other GNU programs.
+
@node CPU Portability
@section Portability between @sc{cpu}s
+@cindex data types, and portability
+@cindex portability, and data types
Even GNU systems will differ because of differences among @sc{cpu}
types---for example, difference in byte ordering and alignment
requirements. It is absolutely essential to handle these differences.
@code{int} will be less than 32 bits. We don't support 16-bit machines
in GNU.
+Similarly, don't make any effort to cater to the possibility that
+@code{long} will be smaller than predefined types like @code{size_t}.
+For example, the following code is ok:
+
+@example
+printf ("size = %lu\n", (unsigned long) sizeof array);
+printf ("diff = %ld\n", (long) (pointer2 - pointer1));
+@end example
+
+1989 Standard C requires this to work, and we know of only one
+counterexample: 64-bit programs on Microsoft Windows IA-64. We will
+leave it to those who want to port GNU programs to that environment
+to figure out how to do it.
+
+Predefined file-size types like @code{off_t} are an exception: they are
+longer than @code{long} on many platforms, so code like the above won't
+work with them. One way to print an @code{off_t} value portably is to
+print its digits yourself, one by one.
+
Don't assume that the address of an @code{int} object is also the
address of its least-significant byte. This is false on big-endian
machines. Thus, don't make the following mistake:
When calling functions, you need not worry about the difference between
pointers of various types, or between pointers and integers. On most
machines, there's no difference anyway. As for the few machines where
-there is a difference, all of them support @sc{ansi} C, so you can use
-prototypes (conditionalized to be active only in @sc{ansi} C) to make
-the code work on those systems.
+there is a difference, all of them support Standard C prototypes, so you can
+use prototypes (perhaps conditionalized to be active only in Standard C)
+to make the code work on those systems.
In certain cases, it is ok to pass integer and pointer arguments
indiscriminately to the same function, and use no prototype on any
@noindent
In practice, this works on all machines, since a pointer is generally
-the widest possible kind of argument, and it is much simpler than any
+the widest possible kind of argument; it is much simpler than any
``correct'' alternative. Be sure @emph{not} to use a prototype for such
functions.
-However, avoid casting pointers to integers unless you really need to.
-Outside of special situations, such casts greatly reduce portability,
-and in most programs they are easy to avoid. In the cases where casting
-pointers to integers is essential---such as, a Lisp interpreter which
-stores type information as well as an address in one word---it is ok to
-do it, but you'll have to make explicit provisions to handle different
-word sizes.
+If you have decided to use Standard C, then you can instead define
+@code{error} using @file{stdarg.h}, and pass the arguments along to
+@code{vfprintf}.
+
+@cindex casting pointers to integers
+Avoid casting pointers to integers if you can. Such casts greatly
+reduce portability, and in most programs they are easy to avoid. In the
+cases where casting pointers to integers is essential---such as, a Lisp
+interpreter which stores type information as well as an address in one
+word---you'll have to make explicit provisions to handle different word
+sizes. You will also need to make provision for systems in which the
+normal range of addresses you can get from @code{malloc} starts far away
+from zero.
@node System Functions
@section Calling System Functions
+@cindex library functions, and portability
+@cindex portability, and library functions
-C implementations differ substantially. @sc{ansi} C reduces but does not
-eliminate the incompatibilities; meanwhile, many users wish to compile
-GNU software with pre-@sc{ansi} compilers. This chapter gives
-recommendations for how to use the more or less standard C library
-functions to avoid unnecessary loss of portability.
+C implementations differ substantially. Standard C reduces but does
+not eliminate the incompatibilities; meanwhile, many GNU packages still
+support pre-standard compilers because this is not hard to do. This
+chapter gives recommendations for how to use the more-or-less standard C
+library functions to avoid unnecessary loss of portability.
@itemize @bullet
@item
-Don't use the value of @code{sprintf}. It returns the number of
+Don't use the return value of @code{sprintf}. It returns the number of
characters written on some systems, but not on all systems.
@item
+Be aware that @code{vfprintf} is not always available.
+
+@item
@code{main} should be declared to return type @code{int}. It should
terminate either by calling @code{exit} or by returning the integer
status code; make sure it cannot ever return an undefined value.
+@cindex declaration for system functions
@item
Don't declare system functions explicitly.
@item
If you must declare a system function, don't specify the argument types.
-Use an old-style declaration, not an @sc{ansi} prototype. The more you
+Use an old-style declaration, not a Standard C prototype. The more you
specify about the function, the more likely a conflict.
@item
@code{realloc}---or put these declarations in configuration files
specific to those systems.
+@cindex string library functions
@item
The string functions require special treatment. Some Unix systems have
a header file @file{string.h}; others have @file{strings.h}. Neither
If you don't include either strings file, you can't get declarations for
the string functions from the header file in the usual way.
-That causes less of a problem than you might think. The newer @sc{ansi}
+That causes less of a problem than you might think. The newer standard
string functions should be avoided anyway because many systems still
don't support them. The string functions you can use are these:
You should pick a single pair of names and use it throughout your
program. (Nowadays, it is better to choose @code{strchr} and
-@code{strrchr} for new programs, since those are the standard @sc{ansi}
+@code{strrchr} for new programs, since those are the standard
names.) Declare both of those names as functions returning @code{char
*}. On systems which don't support those names, define them as macros
in terms of the other pair. For example, here is what to put at the
@node Internationalization
@section Internationalization
+@cindex internationalization
+@pindex gettext
GNU has a library called GNU gettext that makes it easy to translate the
messages in a program into various languages. You should use this
library in every program. Use English for the messages as they appear
Normally, the text domain name should be the same as the name of the
package---for example, @samp{fileutils} for the GNU file utilities.
+@cindex message text, and internationalization
To enable gettext to work well, avoid writing code that makes
assumptions about the structure of words or sentences. When you want
the precise text of a sentence to vary depending on the data, use two or
@node Mmap
@section Mmap
+@findex mmap
Don't assume that @code{mmap} either works on all files or fails
for all files. It may work on some files and fail on others.
@node Documentation
@chapter Documenting Programs
+@cindex documentation
+
+A GNU program should ideally come with full free documentation, adequate
+for both reference and tutorial purposes. If the package can be
+programmed or extended, the documentation should cover programming or
+extending it, as well as just using it.
@menu
* GNU Manuals:: Writing proper manuals.
+* Doc Strings and Manuals:: Compiling doc strings doesn't make a manual.
* Manual Structure Details:: Specific structure conventions.
* License for Manuals:: Writing the distribution terms for a manual.
+* Manual Credits:: Giving credit to documentation contributors.
+* Printed Manuals:: Mentioning the printed manual.
* NEWS File:: NEWS files supplement manuals.
* Change Logs:: Recording Changes
* Man Pages:: Man pages are secondary.
@node GNU Manuals
@section GNU Manuals
-The preferred way to document part of the GNU system is to write a
-manual in the Texinfo formatting language. This makes it possible to
-produce a good quality formatted book, using @TeX{}, and to generate an
-Info file. It is also possible to generate HTML output from Texinfo
-source. See the Texinfo manual, either the hardcopy, or the on-line
-version available through @code{info} or the Emacs Info subsystem
-(@kbd{C-h i}).
+The preferred document format for the GNU system is the Texinfo
+formatting language. Every GNU package should (ideally) have
+documentation in Texinfo both for reference and for learners. Texinfo
+makes it possible to produce a good quality formatted book, using
+@TeX{}, and to generate an Info file. It is also possible to generate
+HTML output from Texinfo source. See the Texinfo manual, either the
+hardcopy, or the on-line version available through @code{info} or the
+Emacs Info subsystem (@kbd{C-h i}).
+
+Nowadays some other formats such as Docbook and Sgmltexi can be
+converted automatically into Texinfo. It is ok to produce the Texinfo
+documentation by conversion this way, as long as it gives good results.
Programmers often find it most natural to structure the documentation
following the structure of the implementation, which they know. But
programs, as well as @code{cmp}. By documenting these programs
together, we can make the whole subject clearer.
-The manual which discusses a program should document all of the
-program's command-line options and all of its commands. It should give
-examples of their use. But don't organize the manual as a list of
+The manual which discusses a program should certainly document all of
+the program's command-line options and all of its commands. It should
+give examples of their use. But don't organize the manual as a list of
features. Instead, organize it logically, by subtopics. Address the
questions that a user will ask when thinking about the job that the
program does.
the framework for a beginner to understand the rest of the manual. The
Bison manual provides a good example of how to do this.
+To serve as a reference, a manual should have an Index that list all the
+functions, variables, options, and important concepts that are part of
+the program. One combined Index should do for a short manual, but
+sometimes for a complex package it is better to use multiple indices.
+The Texinfo manual includes advice on preparing good index entries, see
+@ref{Index Entries, , Making Index Entries, texinfo, The GNU Texinfo
+Manual}, and see @ref{Indexing Commands, , Defining the Entries of an
+Index, texinfo, The GNU Texinfo manual}.
+
Don't use Unix man pages as a model for how to write GNU documentation;
most of them are terse, badly structured, and give inadequate
-explanation of the underlying concepts. (There are, of course
-exceptions.) Also Unix man pages use a particular format which is
+explanation of the underlying concepts. (There are, of course, some
+exceptions.) Also, Unix man pages use a particular format which is
different from what we use in GNU manuals.
Please include an email address in the manual for where to report
Please do not use the term ``illegal'' to refer to erroneous input to a
computer program. Please use ``invalid'' for this, and reserve the term
-``illegal'' for violations of law.
+``illegal'' for activities punishable by law.
+
+@node Doc Strings and Manuals
+@section Doc Strings and Manuals
+
+Some programming systems, such as Emacs, provide a documentation string
+for each function, command or variable. You may be tempted to write a
+reference manual by compiling the documentation strings and writing a
+little additional text to go around them---but you must not do it. That
+approach is a fundamental mistake. The text of well-written
+documentation strings will be entirely wrong for a manual.
+
+A documentation string needs to stand alone---when it appears on the
+screen, there will be no other text to introduce or explain it.
+Meanwhile, it can be rather informal in style.
+
+The text describing a function or variable in a manual must not stand
+alone; it appears in the context of a section or subsection. Other text
+at the beginning of the section should explain some of the concepts, and
+should often make some general points that apply to several functions or
+variables. The previous descriptions of functions and variables in the
+section will also have given information about the topic. A description
+written to stand alone would repeat some of that information; this
+redundance looks bad. Meanwhile, the informality that is acceptable in
+a documentation string is totally unacceptable in a manual.
+
+The only good way to use documentation strings in writing a good manual
+is to use them as a source of information for writing good text.
@node Manual Structure Details
@section Manual Structure Details
+@cindex manual structure
The title page of the manual should state the version of the programs or
packages documented in the manual. The Top node of the manual should
the above patterns. This identifies the node which that item points to
as the node for this purpose, regardless of the node's actual name.
-There will be automatic features for specifying a program name and
-quickly reading just this part of its manual.
+The @samp{--usage} feature of the Info reader looks for such a node
+or menu item in order to find the relevant text, so it is essential
+for every Texinfo file to have one.
If one manual describes several programs, it should have such a node for
-each program described.
+each program described in the manual.
@node License for Manuals
@section License for Manuals
+@cindex license for manuals
-If the manual contains a copy of the GNU GPL or GNU LGPL, or if it
-contains chapters that make political or personal statements, please
-copy the distribution terms of the GNU Emacs Manual, and adapt it by
-modifying appropriately the list of special chapters that may not be
-modified or deleted.
+Please use the GNU Free Documentation License for all GNU manuals that
+are more than a few pages long. Likewise for a collection of short
+documents---you only need one copy of the GNU FDL for the whole
+collection. For a single short document, you can use a very permissive
+non-copyleft license, to avoid taking up space with a long license.
-If the manual does not contain any such chapters, then imitate the
-simpler distribution terms of the Texinfo manual.
+See @uref{http://www.gnu.org/copyleft/fdl-howto.html} for more explanation
+of how to employ the GFDL.
+
+Note that it is not obligatory to include a copy of the GNU GPL or GNU
+LGPL in a manual whose license is neither the GPL nor the LGPL. It can
+be a good idea to include the program's license in a large manual; in a
+short manual, whose size would be increased considerably by including
+the program's license, it is probably better not to include it.
+
+@node Manual Credits
+@section Manual Credits
+@cindex credits for manuals
+
+Please credit the principal human writers of the manual as the authors,
+on the title page of the manual. If a company sponsored the work, thank
+the company in a suitable place in the manual, but do not cite the
+company as an author.
+
+@node Printed Manuals
+@section Printed Manuals
+
+The FSF publishes some GNU manuals in printed form. To encourage sales
+of these manuals, the on-line versions of the manual should mention at
+the very start that the printed manual is available and should point at
+information for getting it---for instance, with a link to the page
+@url{http://www.gnu.org/order/order.html}. This should not be included
+in the printed manual, though, because there it is redundant.
+
+It is also useful to explain in the on-line forms of the manual how the
+user can print out the manual from the sources.
@node NEWS File
@section The NEWS File
+@cindex @file{NEWS} file
In addition to its manual, the package should have a file named
@file{NEWS} which contains a list of user-visible changes worth
@node Change Logs
@section Change Logs
+@cindex change logs
Keep a change log to describe all the changes made to program source
files. The purpose of this is so that people investigating bugs in the
* Style of Change Logs::
* Simple Changes::
* Conditional Changes::
+* Indicating the Part Changed::
@end menu
@node Change Log Concepts
@node Style of Change Logs
@subsection Style of Change Logs
+@cindex change logs, style
-Here are some examples of change log entries:
+Here are some simple examples of change log entries, starting with the
+header line that says who made the change and when, followed by
+descriptions of specific changes. (These examples are drawn from Emacs
+and GCC.)
@example
+1998-08-17 Richard Stallman <rms@@gnu.org>
+
* register.el (insert-register): Return nil.
(jump-to-register): Likewise.
then don't put blank lines between them. Then you can omit the file
name and the asterisk when successive entries are in the same file.
+Break long lists of function names by closing continued lines with
+@samp{)}, rather than @samp{,}, and opening the continuation with
+@samp{(} as in this example:
+
+@example
+* keyboard.c (menu_bar_items, tool_bar_items)
+(Fexecute_extended_command): Deal with `keymap' property.
+@end example
+
@node Simple Changes
@subsection Simple Changes
log.
When you change the calling sequence of a function in a simple fashion,
-and you change all the callers of the function, there is no need to make
-individual entries for all the callers that you changed. Just write in
-the entry for the function being called, ``All callers changed.''
+and you change all the callers of the function to use the new calling
+sequence, there is no need to make individual entries for all the
+callers that you changed. Just write in the entry for the function
+being called, ``All callers changed''---like this:
@example
* keyboard.c (Fcommand_execute): New arg SPECIAL.
@node Conditional Changes
@subsection Conditional Changes
+@cindex conditional changes, and change logs
+@cindex change logs, conditional changes
C programs often contain compile-time @code{#if} conditionals. Many
changes are conditional; sometimes you add a new definition which is
(gethostname) [!HAVE_SOCKETS]: Replace with winsock version.
@end example
+@node Indicating the Part Changed
+@subsection Indicating the Part Changed
+
+Indicate the part of a function which changed by using angle brackets
+enclosing an indication of what the changed part does. Here is an entry
+for a change in the part of the function @code{sh-while-getopts} that
+deals with @code{sh} commands:
+
+@example
+* progmodes/sh-script.el (sh-while-getopts) <sh>: Handle case that
+user-specified option string is empty.
+@end example
+
+
@node Man Pages
@section Man Pages
+@cindex man pages
In the GNU project, man pages are secondary. It is not necessary or
expected for every GNU program to have a man page, but some of them do.
@node Managing Releases
@chapter The Release Process
+@cindex releasing
Making a release is more than just bundling up your source files in a
tar file and putting it up for FTP. You should set up your software so
@node Configuration
@section How Configuration Should Work
+@cindex program configuration
+@pindex configure
Each GNU distribution should come with a shell script named
@code{configure}. This script is given arguments which describe the
kind of machine and system you want to compile the program for.
alternatives for how to describe a machine. Thus, @samp{sun3-sunos4.1}
would be a valid alias. For many programs, @samp{vax-dec-ultrix} would
be an alias for @samp{vax-dec-bsd}, simply because the differences
-between Ultrix and BSD are rarely noticeable, but a few programs
+between Ultrix and @sc{bsd} are rarely noticeable, but a few programs
might need to distinguish them.
@c Real 4.4BSD now runs on some Suns.
There is a shell script called @file{config.sub} that you can use
as a subroutine to validate system types and canonicalize aliases.
+@cindex optional features, configure-time
Other options are permitted to specify in more detail the software
or hardware present on the machine, and include or exclude optional
parts of the package:
Do not use a @samp{--with} option to specify the file name to use to
find certain files. That is outside the scope of what @samp{--with}
options are for.
-
-@item --nfp
-The target machine has no floating point processor.
-
-@item --gas
-The target machine assembler is GAS, the GNU assembler.
-This is obsolete; users should use @samp{--with-gnu-as} instead.
-
-@item --x
-The target machine has the X Window System installed.
-This is obsolete; users should use @samp{--with-x} instead.
@end table
All @code{configure} scripts should accept all of these ``detail''
configuration options in GNU software. We do not want GNU programs to
have idiosyncratic configuration options.
-Packages that perform part of the compilation process may support cross-compilation.
-In such a case, the host and target machines for the program may be
-different. The @code{configure} script should normally treat the
-specified type of system as both the host and the target, thus producing
-a program which works for the same type of machine that it runs on.
+Packages that perform part of the compilation process may support
+cross-compilation. In such a case, the host and target machines for the
+program may be different.
-The way to build a cross-compiler, cross-assembler, or what have you, is
-to specify the option @samp{--host=@var{hosttype}} when running
-@code{configure}. This specifies the host system without changing the
-type of target system. The syntax for @var{hosttype} is the same as
-described above.
+The @code{configure} script should normally treat the specified type of
+system as both the host and the target, thus producing a program which
+works for the same type of machine that it runs on.
-Bootstrapping a cross-compiler requires compiling it on a machine other
-than the host it will run on. Compilation packages accept a
-configuration option @samp{--build=@var{hosttype}} for specifying the
-configuration on which you will compile them, in case that is different
-from the host.
+To configure a cross-compiler, cross-assembler, or what have you, you
+should specify a target different from the host, using the configure
+option @samp{--target=@var{targettype}}. The syntax for
+@var{targettype} is the same as for the host type. So the command would
+look like this:
+
+@example
+./configure @var{hosttype} --target=@var{targettype}
+@end example
Programs for which cross-operation is not meaningful need not accept the
-@samp{--host} option, because configuring an entire operating system for
-cross-operation is not a meaningful thing.
+@samp{--target} option, because configuring an entire operating system for
+cross-operation is not a meaningful operation.
+
+Bootstrapping a cross-compiler requires compiling it on a machine other
+than the host it will run on. Compilation packages accept a
+configuration option @samp{--build=@var{buildtype}} for specifying the
+configuration on which you will compile them, but the configure script
+should normally guess the build machine type (using
+@file{config.guess}), so this option is probably not necessary. The
+host and target types normally default from the build type, so in
+bootstrapping a cross-compiler you must specify them both explicitly.
Some programs have ways of configuring themselves automatically. If
your program is set up to do this, your @code{configure} script can simply
@node Releases
@section Making Releases
+@cindex packaging
Package the distribution of @code{Foo version 69.96} up in a gzipped tar
file with the name @file{foo-69.96.tar.gz}. It should unpack into a
and never changed automatically; non-source files are produced from
source files by programs under the control of the Makefile.
+@cindex @file{README} file
The distribution should contain a file named @file{README} which gives
the name of the package, and a general description of what it does. It
is also good to explain the purpose of each of the first-level
are truncated to @file{foobarha.c} and @file{foobarha.o}, which are
distinct.
+@cindex @file{texinfo.tex}, in a distribution
Include in your distribution a copy of the @file{texinfo.tex} you used
to test print any @file{*.texinfo} or @file{*.texi} files.
@node References
@chapter References to Non-Free Software and Documentation
+@cindex references to non-free material
A GNU program should not recommend use of any non-free program. We
can't stop some people from writing proprietary programs, or stop other
undermine our position by recommending use of documentation that isn't
free.
+@node Index
+@unnumbered Index
+@printindex cp
+
@contents
@bye
+Local variables:
+update-date-leading-regexp: "@c This date is automagically updated when you save this file:\n@set lastupdate "
+update-date-trailing-regexp: ""
+eval: (load "/gd/gnuorg/update-date.el")
+eval: (add-hook 'write-file-hooks 'update-date)
+compile-command: "make just-standards"
+End:
projects / chise / xemacs-chise.git.1 / blobdiff