--- /dev/null
+\input texinfo @c -*-texinfo-*-
+@c %**start of header
+@setfilename standards.text
+@settitle GNU Coding Standards
+@c %**end of header
+
+@setchapternewpage off
+
+@ifinfo
+Copyright (C) 1992 Free Software Foundation
+Permission is granted to make and distribute verbatim copies of
+this manual provided the copyright notice and this permission notice
+are preserved on all copies.
+
+@ignore
+Permission is granted to process this file through TeX and print the
+results, provided the printed document carries copying permission
+notice identical to this one except for the removal of this paragraph
+(this paragraph not being relevant to the printed manual).
+@end ignore
+
+Permission is granted to copy and distribute modified versions of this
+manual under the conditions for verbatim copying, provided that the entire
+resulting derived work is distributed under the terms of a permission
+notice identical to this one.
+
+Permission is granted to copy and distribute translations of this manual
+into another language, under the above conditions for modified versions,
+except that this permission notice may be stated in a translation approved
+by the Free Software Foundation.
+@end ifinfo
+
+@titlepage
+@sp 10
+@titlefont{GNU Coding Standards}
+@author{Richard Stallman}
+@author{last updated 21 April 1992}
+@c Note date also appears below.
+@page
+
+@vskip 0pt plus 1filll
+Copyright @copyright{} 1992 Free Software Foundation
+
+Permission is granted to make and distribute verbatim copies of
+this manual provided the copyright notice and this permission notice
+are preserved on all copies.
+
+Permission is granted to copy and distribute modified versions of this
+manual under the conditions for verbatim copying, provided that the entire
+resulting derived work is distributed under the terms of a permission
+notice identical to this one.
+
+Permission is granted to copy and distribute translations of this manual
+into another language, under the above conditions for modified versions,
+except that this permission notice may be stated in a translation approved
+by Free Software Foundation.
+@end titlepage
+
+@ifinfo
+@node Top, Reading Non-Free Code, (dir), (dir)
+@top Version
+
+Last updated 21 April 1992.
+@c Note date also appears above.
+@end ifinfo
+
+@menu
+* Reading Non-Free Code:: Referring to Proprietary Programs
+* Contributions:: Accepting Contributions
+* Change Logs:: Recording Changes
+* Compatibility:: Compatibility with Other Implementations
+* Makefiles:: Makefile Conventions
+* Configuration:: How Configuration Should Work
+* Source Language:: Using Languages Other Than C
+* Formatting:: Formatting Your Source Code
+* Comments:: Commenting Your Work
+* Syntactic Conventions:: Clean Use of C Constructs
+* Names:: Naming Variables and Functions
+* Using Extensions:: Using Non-standard Features
+* Semantics:: Program Behaviour for All Programs
+* Errors:: Formatting Error Messages
+* Libraries:: Library Behaviour
+* Portability:: Portability As It Applies to GNU
+* User Interfaces:: Standards for Command Line Interfaces
+* Documentation:: Documenting Programs
+* Releases:: Making Releases
+@end menu
+
+@node Reading Non-Free Code
+@chapter Referring to Proprietary Programs
+
+Don't in any circumstances refer to Unix source code for or during
+your work on GNU! (Or to any other proprietary programs.)
+
+If you have a vague recollection of the internals of a Unix program,
+this does not absolutely mean you can't write an imitation of it, but
+do try to organize the imitation internally along different lines,
+because this is likely to make the details of the Unix version
+irrelevant and dissimilar to your results.
+
+For example, Unix utilities were generally optimized to minimize
+memory use; if you go for speed instead, your program will be very
+different. You could keep the entire input file in core and scan it
+there instead of using stdio. Use a smarter algorithm discovered more
+recently than the Unix program. Eliminate use of temporary files. Do
+it in one pass instead of two (we did this in the assembler).
+
+Or, on the contrary, emphasize simplicity instead of speed. For some
+applications, the speed of today's computers makes simpler algorithms
+adequate.
+
+Or go for generality. For example, Unix programs often have static
+tables or fixed-size strings, which make for arbitrary limits; use
+dynamic allocation instead. Make sure your program handles NULs and
+other funny characters in the input files. Add a programming language
+for extensibility and write part of the program in that language.
+
+Or turn some parts of the program into independently usable libraries.
+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
+@chapter Accepting Contributions
+
+If someone else sends you a piece of code to add to the program you are
+working on, we need legal papers to use it---the same sort of legal
+papers we will need to get from you. @emph{Each} significant
+contributor to a program must sign some sort of legal papers in order
+for us to have clear title to the program. The main author alone is not
+enough.
+
+So, before adding in any contributions from other people, tell us
+so we can arrange to get the papers. Then wait until we tell you
+that we have received the signed papers, before you actually use the
+contribution.
+
+This applies both before you release the program and afterward. If
+you receive diffs to fix a bug, and they make significant change, we
+need legal papers for it.
+
+You don't need papers for changes of a few lines here or there, since
+they are not significant for copyright purposes. Also, you don't need
+papers if all you get from the suggestion is some ideas, not actual code
+which you use. For example, if you write a different solution to the
+problem, you don't need to get papers.
+
+I know this is frustrating; it's frustrating for us as well. But if
+you don't wait, you are going out on a limb---for example, what if the
+contributor's employer won't sign a disclaimer? You might have to take
+that code out again!
+
+The very worst thing is if you forget to tell us about the other
+contributor. We could be very embarrassed in court some day as a
+result.
+
+@node Change Logs
+@chapter Change Logs
+
+Keep a change log for each directory, describing the changes made to
+source files in that directory. The purpose of this is so that people
+investigating bugs in the future will know about the changes that
+might have introduced the bug. Often a new bug can be found by
+looking at what was recently changed. More importantly, change logs
+can help eliminate conceptual inconsistencies between different parts
+of a program; they can give you a history of how the conflicting
+concepts arose.
+
+Use the Emacs command @kbd{M-x add-change} to start a new entry in the
+change log. An entry should have an asterisk, the name of the changed
+file, and then in parentheses the name of the changed functions,
+variables or whatever, followed by a colon. Then describe the changes
+you made to that function or variable.
+
+Separate unrelated entries with blank lines. When two entries
+represent parts of the same change, so that they work together, 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.
+
+Here are some examples:
+
+@example
+* register.el (insert-register): Return nil.
+(jump-to-register): Likewise.
+
+* sort.el (sort-subr): Return nil.
+
+* tex-mode.el (tex-bibtex-file, tex-file, tex-region):
+Restart the tex shell if process is gone or stopped.
+(tex-shell-running): New function.
+
+* expr.c (store_one_arg): Round size up for move_block_to_reg.
+(expand_call): Round up when emitting USE insns.
+* stmt.c (assign_parms): Round size up for move_block_from_reg.
+@end example
+
+There's no need to describe here the full purpose of the changes or how
+they work together. It is better to put this explanation in comments in
+the code. That's why just ``New function'' is enough; there is a
+comment with the function in the source to explain what it does.
+
+However, sometimes it is useful to write one line to describe the
+overall purpose of a large batch of changes.
+
+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. Just write in
+the entry for the function being called, ``All callers changed.''
+
+When you change just comments or doc strings, it is enough to write an
+entry for the file, without mentioning the functions. Write just,
+``Doc fix.'' There's no need to keep a change log for documentation
+files. This is because documentation is not susceptible to bugs that
+are hard to fix. Documentation does not consist of parts that must
+interact in a precisely engineered fashion; to correct an error, you
+need not know the history of the erroneous passage.
+
+
+@node Compatibility
+@chapter Compatibility with Other Implementations
+
+With certain 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.
+
+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} 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.
+
+When a feature is used only by users (not by programs or command
+files), and it is done poorly in Unix, feel free to replace it
+completely with something totally different and better. (For example,
+vi is replaced with Emacs.) But it is nice to offer a compatible
+feature as well. (There is a free vi clone, so we offer it.)
+
+Additional useful features not in Berkeley Unix are welcome.
+Additional programs with no counterpart in Unix may be useful,
+but our first priority is usually to duplicate what Unix already
+has.
+
+
+@node Makefiles
+@chapter Makefile Conventions
+
+This chapter describes conventions for writing Makefiles.
+
+@menu
+* Makefile Basics::
+* Standard Targets::
+* Command Variables::
+* Directory Variables::
+@end menu
+
+@node Makefile Basics
+@section General Conventions for Makefiles
+
+Every Makefile should contain this line:
+
+@example
+SHELL = /bin/sh
+@end example
+
+@noindent
+to avoid trouble on systems where the @code{SHELL} variable might be
+inherited from the environment.
+
+Don't assume that @file{.} is in the path for command execution. When
+you need to run programs that are files in the current directory, always
+use @file{./} to make sure the proper file is run regardless of the
+current path.
+
+@node Standard Targets
+@section Standard Targets for Users
+
+All GNU programs should have the following targets in their Makefiles:
+
+@table @samp
+@item all
+Compile the entire program.
+
+@item install
+Compile the program and copy the executables, libraries, and so on to
+the file names where they should reside for actual use. If there is a
+simple test to verify that a program is properly installed then run that
+test.
+
+@item clean
+Delete all files from the current directory that are normally created by
+building the program. Don't delete the files that record the
+configuration. Also preserve files that could be made by building, but
+normally aren't because the distribution comes with them.
+
+@item distclean
+Delete all files from the current directory that are created by
+configuring or building the program. This should leave only the files
+that would be in the distribution.
+
+@item mostlyclean
+Like @samp{clean}, but may refrain from deleting a few files that people
+normally don't want to recompile. For example, the @samp{mostlyclean}
+target for GCC does not delete @file{libgcc.a}, because recompiling it
+is rarely necessary and takes a lot of time.
+
+@item realclean
+Delete everything from the current directory that can be reconstructed
+with this Makefile. This typically includes everything deleted by
+distclean, plus more: C source files produced by Bison, tags tables,
+info files, and so on.
+
+@item TAGS
+Update a tags table for this program.
+
+@item dist
+Create a distribution tar file for this program. The tar file should be
+set up so that the file names in the tar file start with a subdirectory
+name which is the name of the package it is a distribution for. This
+name can include the version number.
+
+For example, the distribution tar file of GCC version 1.40 unpacks into
+a subdirectory named @file{gcc-1.40}.
+
+The easiest way to do this is to create a subdirectory appropriately
+named, use @code{ln} or @code{cp} to install the proper files in it, and
+then @code{tar} that subdirectory.
+
+The @code{dist} target should explicitly depend on all non-source files
+that are in the distribution, to make sure they are up to date in the
+distribution. @xref{Releases}.
+
+@item check
+Perform self-tests (if any). The user must build the program before
+running the tests, but need not install the program; you should write
+the self-tests so that they work when the program is built but not
+installed.
+@end table
+
+@node Command Variables
+@section Variables for Specifying Commands
+
+Makefiles should provide variables for overriding certain commands, options,
+and so on.
+
+In particular, you should run most utility programs via variables.
+Thus, if you use Bison, have a variable named @code{BISON} whose default
+value is set with @samp{BISON = bison}, and refer to it with
+@code{$(BISON)} whenever you need to use Bison.
+
+Each program-name variable should come with an options variable that is
+used to supply options to the program. Append @samp{FLAGS} to the
+program-name variable name to get the options variable name---for
+example, @code{BISONFLAGS}. (The name @code{CFLAGS} is an exception to
+this rule, but we keep it because it is standard.)
+
+File-management utilities such as @code{ln}, @code{rm}, @code{mv}, and
+so on need not be referred to through variables in this way, since users
+don't need to replace them with other programs.
+
+Every Makefile should define the variable @code{INSTALL}, which is the
+basic command for installing a file into the system.
+
+Every Makefile should also define variables @code{INSTALL_PROGRAM} and
+@code{INSTALL_DATA}. (The default for each of these should be
+@code{$(INSTALL)}.) Then it should use those variables as the commands
+for actual installation, for executables and nonexecutables
+respectively. Use these variables as follows:
+
+@example
+$(INSTALL_PROGRAM) foo $@{bindir@}/foo
+$(INSTALL_DATA) libfoo.a $@{libdir@}/libfoo.a
+@end example
+
+@noindent
+(Always use a file name, not a directory name, as the second argument.
+Use a separate command for each file to be installed.)
+
+@node Directory Variables
+@section Variables for Installation Directories
+
+Installation directories should always be named by variables, so it is
+easy to install in a nonstandard place. The standard names for these
+variables are:
+
+@table @samp
+@item bindir
+The directory for installing executable programs that users can run.
+This should normally be @file{/usr/local/bin}, but it should be based on
+the value of @code{$(prefix)}.
+
+@item datadir
+The directory for installing read-only data files which the programs
+refer to while they run. This directory is used for files which are
+independent of the type of machine being used. This should normally be
+@file{/usr/local/lib}, but it should be based on the value of
+@code{$(prefix)}.
+
+@item statedir
+The directory for installing data files which the programs modify while
+they run. These files should be independent of the type of machine
+being used, and it should be possible to share them among machines at a
+network installation. This should normally be @file{/usr/local/lib},
+but it should be based on the value of @code{$(prefix)}.
+
+@item libdir
+The directory for installing executable files to be run by the program
+rather than by users. Object files and libraries of object code should
+also go in this directory. The idea is that this directory is used for
+files that pertain to a specific machine architecture. This should
+normally be @file{/usr/local/lib}, but it should be based on the value of
+@code{$(prefix)}.
+
+@item includedir
+The directory for installing @samp{#include} header files to be included
+by user programs. This should normally be @file{/usr/local/include},
+but it should be based on the value of @code{$(prefix)}.
+
+Most compilers other than GCC do not look for header files in
+@file{/usr/local/include}. So installing the header files this way is
+only useful with GCC. Sometimes this is not a problem because some
+libraries are only really intended to work with GCC. But some libraries
+are intended to work with other compilers. They should install their
+header files in two places, one specified by includedir and one
+specified by oldincludedir
+
+@item oldincludedir
+The directory for installing @samp{#include} header files for use with
+compilers other than GCC. This should normally be @file{/usr/include}.
+
+The Makefile commands should check whether the value of
+@code{oldincludedir} is empty. If it is, they should not try to use
+it; they should cancel the second installation of the header files.
+
+@item mandir
+The directory for installing the man pages (if any) for this package.
+It should include the suffix for the proper section of the
+manual---usually @samp{1} for a utility.
+
+@item man1dir
+The directory for installing section 1 man pages.
+@item man2dir
+The directory for installing section 2 man pages.
+@item @dots{}
+Use these names instead of @samp{mandir} if the package needs to install man
+pages in more than one section of the manual.
+
+@strong{Don't make the primary documentation for any GNU software be a
+man page. Write a manual in Texinfo instead. Man pages are just for
+the sake of people running GNU software on Unix, which is a secondary
+application only.}
+
+@item manext
+The file name extension for the installed man page. This should contain
+a period followed by the appropriate digit.
+
+@item infodir
+The directory for installing the info files for this package. By
+default, it should be @file{/usr/local/info}, but it should be based on the
+value of @code{$(prefix)}.
+
+@item srcdir
+The directory for the sources being compiled. The value of this
+variable is normally inserted by the @code{configure} shell script.
+
+@item prefix
+A prefix used in constructing the default values of the variables listed
+above. The default value of @code{prefix} should be @file{/usr/local}
+(at least for now).
+@end table
+
+For example:
+
+@example
+# Common prefix for installation directories.
+# NOTE: This directory must exist when you start installation.
+prefix = /usr/local
+# Directory in which to put the executable for the command `gcc'
+bindir = $(prefix)/bin
+# Directory in which to put the directories used by the compiler.
+libdir = $(prefix)/lib
+@end example
+
+
+@node Configuration
+@chapter How Configuration Should Work
+
+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.
+
+The @code{configure} script must record the configuration options so
+that they affect compilation.
+
+One way to do this is to make a link from a standard name such as
+@file{config.h} to the proper configuration file for the chosen system.
+If you use this technique, the distribution should @emph{not} contain a
+file named @file{config.h}. This is so that people won't be able to
+build the program without configuring it first.
+
+Another thing that @code{configure} can do is to edit the Makefile. If
+you do this, the distribution should @emph{not} contain a file named
+@file{Makefile}. Instead, include a file @file{Makefile.in} which
+contains the input used for editing. Once again, this is so that people
+won't be able to build the program without configuring it first.
+
+If @code{configure} does write the @file{Makefile}, then @file{Makefile}
+should have a target named @file{Makefile} which causes @code{configure}
+to be rerun, setting up the same configuration that was set up last
+time. The files that @code{configure} reads should be listed as
+dependencies of @file{Makefile}.
+
+All the files which are output from the @code{configure} script should
+have comments at the beginning explaining that they were generated
+automatically using @code{configure}. This is so that users won't think
+of trying to edit them by hand.
+
+The @code{configure} script should write a file named @file{config.status}
+which describes which configuration options were specified when the
+program was last configured. This file should be a shell script which,
+if run, will recreate the same configuration.
+
+The @code{configure} script should accept an option of the form
+@samp{--srcdir=@var{dirname}} to specify the directory where sources are found
+(if it is not the current directory). This makes it possible to build
+the program in a separate directory, so that the actual source directory
+is not modified.
+
+If the user does not specify @samp{--srcdir}, then @code{configure} should
+check both @file{.} and @file{..} to see if it can find the sources. If
+it finds the sources in one of these places, it should use them from
+there. Otherwise, it should report that it cannot find the sources, and
+should exit with nonzero status.
+
+Usually the easy way to support @samp{--srcdir} is by editing a
+definition of @code{VPATH} into the Makefile. Some rules may need to
+refer explicitly to the specified source directory. To make this
+possible, @code{configure} can add to the Makefile a variable named
+@code{srcdir} whose value is precisely the specified directory.
+
+The @code{configure} script should also take an argument which specifies the
+type of system to build the program for. This argument should look like
+this:
+
+@example
+@var{cpu}-@var{company}-@var{system}
+@end example
+
+For example, a Sun 3 might be @samp{m68k-sun-sunos4.1}.
+
+The @code{configure} script needs to be able to decode all plausible
+alternatives for how to describe a machine. Thus, @samp{sun3-sunos4.1}
+would be a valid alias. So would @samp{sun3-bsd4.2}, since Sunos is
+basically @sc{BSD} and no other @sc{BSD} system is used on a Sun. For many
+programs, @samp{vax-dec-ultrix} would be an alias for
+@samp{vax-dec-bsd}, simply because the differences between Ultrix and
+@sc{BSD} are rarely noticeable, but a few programs might need to distinguish
+them.
+
+There is a shell script called @file{config.sub} that you can use
+as a subroutine to validate system types and canonicalize aliases.
+
+Other options are permitted to specify in more detail the software
+or hardware are present on the machine:
+
+@table @samp
+@item --with-@var{package}
+The package @var{package} will be installed, so configure this package
+to work with @var{package}.
+
+Possible values of @var{package} include @samp{x}, @samp{gnu-as} (or
+@samp{gas}), @samp{gnu-ld}, @samp{gnu-libc}, and @samp{gdb}.
+
+@item --nfp
+The target machine has no floating point processor.
+
+@item --gas
+The target machine assembler is GAS, the GNU assembler.
+This is obsolete; use @samp{--with-gnu-as} instead.
+
+@item --x
+The target machine has the X Window system installed.
+This is obsolete; use @samp{--with-x} instead.
+@end table
+
+All @code{configure} scripts should accept all of these ``detail''
+options, whether or not they make any difference to the particular
+package at hand. In particular, they should accept any option that
+starts with @samp{--with-}. This is so users will be able to configure
+an entire GNU source tree at once with a single set of options.
+
+Packages that perform part of compilation 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.
+
+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.
+
+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.
+
+Some programs have ways of configuring themselves automatically. If
+your program is set up to do this, your @code{configure} script can simply
+ignore most of its arguments.
+
+
+@node Source Language
+@chapter 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. So please write in C.
+
+There are three exceptions for this rule:
+
+@itemize @bullet
+@item
+It is okay to use a special language if the same program contains an
+interpreter for that language.
+
+Thus, it is not a problem that GNU Emacs contains code written in Emacs
+Lisp, because it comes with a Lisp interpreter.
+
+@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 not of extremely widespread interest, then perhaps
+it's not important if the application is inconvenient to install.
+@end itemize
+
+@node Formatting
+@chapter Formatting Your Source Code
+
+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
+for open-braces in column zero to find the beginnings of C functions.
+These tools will not work on code not formatted that way.
+
+It is also important for function definitions to start the name of the
+function in column zero. This helps people to search for function
+definitions, and may also help certain tools recognize them. Thus,
+the proper format is this:
+
+@example
+static char *
+concat (s1, s2) /* Name starts in column zero here */
+ char *s1, *s2;
+@{ /* Open brace in column zero here */
+ @dots{}
+@}
+@end example
+
+@noindent
+or, if you want to use @sc{ANSI} C, format the definition like this:
+
+@example
+static char *
+concat (char *s1, char *s2)
+@{
+ @dots{}
+@}
+@end example
+
+In @sc{ANSI} C, if the arguments don't fit nicely on one line,
+split it like this:
+
+@example
+int
+lots_of_args (int an_integer, long a_long, short a_short,
+ double a_double, float a_float)
+@dots{}
+@end example
+
+For the body of the function, we prefer code formatted like this:
+
+@example
+if (x < foo (y, z))
+ haha = bar[4] + 5;
+else
+ @{
+ while (z)
+ @{
+ haha += foo (z, z);
+ z--;
+ @}
+ return ++x + bar ();
+ @}
+@end example
+
+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:
+
+@example
+if (foo_this_is_long && bar > win (x, y, z)
+ && remaining_condition)
+@end example
+
+Try to avoid having two operators of different precedence at the same
+level of indentation. For example, don't write this:
+
+@example
+mode = (inmode[j] == VOIDmode
+ || GET_MODE_SIZE (outmode[j]) > GET_MODE_SIZE (inmode[j])
+ ? outmode[j] : inmode[j]);
+@end example
+
+Instead, use extra parentheses so that the indentation shows the nesting:
+
+@example
+mode = ((inmode[j] == VOIDmode
+ || (GET_MODE_SIZE (outmode[j]) > GET_MODE_SIZE (inmode[j])))
+ ? outmode[j] : inmode[j]);
+@end example
+
+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:
+
+@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
+
+Format do-while statements like this:
+
+@example
+do
+ @{
+ a = foo (a);
+ @}
+while (a > 0);
+@end example
+
+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
+@chapter Commenting Your Work
+
+Every program should start with a comment saying briefly what it is for.
+Example: @samp{fmt - filter for simple filling of text}.
+
+Please put a comment on each function saying what the function does,
+what sorts of arguments it gets, and what the possible values of
+arguments mean and are used for. It is not necessary to duplicate in
+words the meaning of the C argument declarations, if a C type is being
+used in its customary fashion. If there is anything nonstandard about
+its use (such as an argument of type @code{char *} which is really the
+address of the second character of a string, not the first), or any
+possible values that would not work the way one would expect (such as,
+that strings containing newlines are not guaranteed to work), be sure
+to say so.
+
+Also explain the significance of the return value, if there is one.
+
+Please put two spaces after the end of a sentence in your comments, so
+that the Emacs sentence commands will work. Also, please write
+complete sentences and capitalize the first word. If a lower-case
+identifer comes at the beginning of a sentence, don't capitalize it!
+Changing the spelling makes it a different identifier. If you don't
+like starting a sentence with a lower case letter, write the sentence
+differently (e.g. ``The identifier lower-case is @dots{}'').
+
+The comment on a function is much clearer if you use the argument
+names to speak about the argument values. The variable name itself
+should be lower case, but write it in upper case when you are speaking
+about the value rather than the variable itself. Thus, ``the inode
+number @var{node_num}'' rather than ``an inode''.
+
+There is usually no purpose in restating the name of the function in
+the comment before it, because the reader can see that for himself.
+There might be an exception when the comment is so long that the function
+itself would be off the bottom of the screen.
+
+There should be a comment on each static variable as well, like this:
+
+@example
+/* Nonzero means truncate lines in the display;
+ zero means continue them. */
+
+int truncate_lines;
+@end example
+
+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
+its sense}. @samp{#else} should have a comment describing the condition
+@emph{and sense} of the code that follows. For example:
+
+@example
+#ifdef foo
+ @dots{}
+#else /* not foo */
+ @dots{}
+#endif /* not foo */
+@end example
+
+@noindent
+but, by contrast, write the comments this way for a @samp{#ifndef}:
+
+@example
+#ifndef foo
+ @dots{}
+#else /* foo */
+ @dots{}
+#endif /* foo */
+@end example
+
+
+@node Syntactic Conventions
+@chapter Clean Use of C Constructs
+
+Please explicitly declare all arguments to functions.
+Don't omit them just because they are ints.
+
+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 (somewhere before the first function definition in the file),
+or else should go in a header file. Don't put extern declarations
+inside functions.
+
+Don't declare multiple variables in one declaration that spans lines.
+Start a new declaration on each line, instead. For example, instead
+of this:
+
+@example
+int foo,
+ bar;
+@end example
+
+@noindent
+write either this:
+
+@example
+int foo, bar;
+@end example
+
+@noindent
+or this:
+
+@example
+int foo;
+int bar;
+@end example
+
+@noindent
+(If they are global variables, each should have a comment preceding it
+anyway.)
+
+When you have an if-else statement nested in another if statement,
+always put braces around the if-else. Thus, never write like this:
+
+@example
+if (foo)
+ if (bar)
+ win ();
+ else
+ lose ();
+@end example
+
+@noindent
+always like this:
+
+@example
+if (foo)
+ @{
+ if (bar)
+ win ();
+ else
+ lose ();
+ @}
+@end example
+
+If you have an if statement nested inside of an else statement,
+either write @code{else if} on one line, like this,
+
+@example
+if (foo)
+ @dots{}
+else if (bar)
+ @dots{}
+@end example
+
+@noindent
+with its then-part indented like the preceding then-part, or write the
+nested if within braces like this:
+
+@example
+if (foo)
+ @dots{}
+else
+ @{
+ if (bar)
+ @dots{}
+ @}
+@end example
+
+Don't declare both a structure tag and variables or typedefs in the
+same declaration. Instead, declare the structure tag separately
+and then use it to declare the variables or typedefs.
+
+Try to avoid assignments inside if-conditions. For example, don't
+write this:
+
+@example
+if ((foo = (char *) malloc (sizeof *foo)) == 0)
+ fatal ("virtual memory exhausted");
+@end example
+
+@noindent
+instead, write this:
+
+@example
+foo = (char *) malloc (sizeof *foo);
+if (foo == 0)
+ fatal ("virtual memory exhausted");
+@end example
+
+Don't make the program ugly to placate lint. Please don't insert any
+casts to void. Zero without a cast is perfectly fine as a null
+pointer constant.
+
+
+@node Names
+@chapter Naming Variables and Functions
+
+Please use underscores to separate words in a name, so that the Emacs
+word commands can be useful within them. Stick to lower case; reserve
+upper case for macros and enum constants, and for name-prefixes that
+follow a uniform convention.
+
+For example, you should use names like @code{ignore_space_change_flag};
+don't use names like @code{iCantReadThis}.
+
+Variables that indicate whether command-line options have been
+specified should be named after the meaning of the option, not after
+the option-letter. A comment should state both the exact meaning of
+the option and its letter. For example,
+
+@example
+/* Ignore changes in horizontal whitespace (-b). */
+int ignore_space_change_flag;
+@end example
+
+When you want to define names with constant integer values, use
+@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 System V.
+
+
+@node Using Extensions
+@chapter Using Non-standard Features
+
+Many GNU facilities that already exist support a number of convenient
+extensions over the comparable Unix facilities. Whether to use these
+extensions in implementing your program is a difficult question.
+
+On the one hand, using the extensions can make a cleaner program.
+On the other hand, people will not be able to build the program
+unless the other GNU tools are available. This might cause the
+program to work on fewer kinds of machines.
+
+With some extensions, it might be easy to provide both alternatives.
+For example, you can define functions with a ``keyword'' @code{INLINE}
+and define that as a macro to expand into either @code{inline} or
+nothing, depending on the compiler.
+
+In general, perhaps it is best not to use the extensions if you can
+straightforwardly do without them, but to use the extensions if they
+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.
+
+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.
+
+Since most computer systems do not yet implement @sc{ANSI} C, using the
+@sc{ANSI} C features is effectively using a GNU extension, so the
+same considerations apply. (Except for @sc{ANSI} features that we
+discourage, such as trigraphs---don't ever use them.)
+
+@node Semantics
+@chapter Program Behaviour for All Programs
+
+Avoid arbitrary limits on the length or number of @emph{any} data
+structure, including filenames, 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.
+
+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 for
+interface to certain types of printers that can't handle those characters.
+
+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
+system call, as well as the name of the file if any and the name of the
+utility. Just ``cannot open foo.c'' or ``stat failed'' is not
+sufficient.
+
+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,
+@code{realloc} may get a different block if you ask for less space.
+
+In Unix, @code{realloc} can destroy the storage block if it returns
+zero. GNU @code{realloc} does not have this bug: if it fails, the
+original block is unchanged. Feel free to assume the bug is fixed. If
+you wish to run your program on Unix, and wish to avoid lossage in this
+case, you can use the GNU @code{malloc}.
+
+You must expect @code{free} to alter the contents of the block that was
+freed. Anything you want to fetch from the block, you must fetch before
+calling @code{free}.
+
+Use @code{getopt_long} to decode arguments, unless the argument syntax
+makes this unreasonable.
+
+When static storage is to be written in during program execution, use
+explicit C code to initialize it. Reserve C initialized declarations
+for data that will not be changed.
+
+Try to avoid low-level interfaces to obscure Unix data structures (such
+as file directories, utmp, or the layout of kernel memory), since these
+are less likely to work compatibly. If you need to find all the files
+in a directory, use @code{readdir} or some other high-level interface. These
+will be supported compatibly by GNU.
+
+By default, the GNU system will provide the signal handling
+functions of @sc{BSD} and of @sc{POSIX}. So GNU software should be
+written to use these.
+
+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
+to read the source code and run a debugger. So explain the problem with
+comments in the source. The relevant data will be in variables, which
+are easy to examine with the debugger, so there is no point moving them
+elsewhere.
+
+
+@node Errors
+@chapter Formatting Error Messages
+
+Error messages from compilers should look like this:
+
+@example
+@var{source-file-name}:@var{lineno}: @var{message}
+@end example
+
+Error messages from other noninteractive programs should look like this:
+
+@example
+@var{program}:@var{source-file-name}:@var{lineno}: @var{message}
+@end example
+
+@noindent
+when there is an appropriate source file, or like this:
+
+@example
+@var{program}: @var{message}
+@end example
+
+@noindent
+when there is no relevant source file.
+
+In an interactive program (one that is reading commands from a
+terminal), it is better not to include the program name in an error
+message. The place to indicate which program is running is in the
+prompt or with the screen layout. (When the same program runs with
+input from a source other than a terminal, it is not interactive and
+would do best to print error messages using the noninteractive style.)
+
+The string @var{message} should not begin with a capital letter when
+it follows a program name and/or filename. Also, it should not end
+with a period.
+
+Error messages from interactive programs, and other messages such as
+usage messages, should start with a capital letter. But they should not
+end with a period.
+
+
+@node Libraries
+@chapter Library Behaviour
+
+Try to make library functions reentrant. If they need to do dynamic
+storage allocation, at least try to avoid any nonreentrancy aside from
+that of @code{malloc} itself.
+
+Here are certain name conventions for libraries, to avoid name
+conflicts.
+
+Choose a name prefix for the library, more than two characters long.
+All external function and variable names should start with this
+prefix. In addition, there should only be one of these in any given
+library member. This usually means putting each one in a separate
+source file.
+
+An exception can be made when two external symbols are always used
+together, so that no reasonable program could use one without the
+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.
+
+Static functions and variables can be used as you like and need not
+fit any naming convention.
+
+
+@node Portability
+@chapter Portability As It Applies to GNU
+
+Much of what is called ``portability'' in the Unix world refers to
+porting to different Unix versions. This is not relevant to GNU
+software, because its purpose is to run on top of one and only
+one kernel, the GNU kernel, compiled with one and only one C
+compiler, the GNU C compiler. The amount and kinds of variation
+among GNU systems on different cpu's will be like the variation
+among Berkeley 4.3 systems on different cpu's.
+
+It is difficult to be sure exactly what facilities the GNU kernel
+will provide, since it isn't finished yet. Therefore, assume you can
+use anything in 4.3; just avoid using the format of semi-internal data
+bases (e.g., directories) when there is a higher-level alternative
+(readdir).
+
+You can freely assume any reasonably standard facilities in the C
+language, libraries or kernel, because we will find it necessary to
+support these facilities in the full GNU system, whether or not we
+have already done so. The fact that there may exist kernels or C
+compilers that lack these facilities is irrelevant as long as the GNU
+kernel and C compiler support them.
+
+It remains necessary to worry about differences among cpu types, such
+as the difference in byte ordering and alignment restrictions. It's
+unlikely that 16-bit machines will ever be supported by GNU, so there
+is no point in spending any time to consider the possibility that an
+int will be less than 32 bits.
+
+You can assume that all pointers have the same format, regardless
+of the type they point to, and that this is really an integer.
+There are some weird machines where this isn't true, but they aren't
+important; don't waste time catering to them. Besides, eventually
+we will put function prototypes into all GNU programs, and that will
+probably make your program work even on weird machines.
+
+Since some important machines (including the 68000) are big-endian,
+it is important not to assume that the address of an int object
+is also the address of its least-significant byte. Thus, don't
+make the following mistake:
+
+@example
+int c;
+@dots{}
+while ((c = getchar()) != EOF)
+ write(file_descriptor, &c, 1);
+@end example
+
+You can assume that it is reasonable to use a meg of memory. Don't
+strain to reduce memory usage unless it can get to that level. If
+your program creates complicated data structures, just make them in
+core and give a fatal error if malloc returns zero.
+
+If a program works by lines and could be applied to arbitrary
+user-supplied input files, it should keep only a line in memory, because
+this is not very hard and users will want to be able to operate on input
+files that are bigger than will fit in core all at once.
+
+
+@node User Interfaces
+@chapter Standards for Command Line Interfaces
+
+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.
+
+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}
+will normally permit options anywhere among the arguments unless the
+special argument @samp{--} is used. This is not what @sc{POSIX}
+specifies; it is a GNU extension.
+
+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
+@code{getopt_long}.
+
+It is usually a good idea for file names given as ordinary arguments
+to be input files only; any output files would be specified using
+options (preferably @samp{-o}). Even if you allow an output file name
+as an ordinary argument for compatibility, try to provide a suitable
+option as well. This will lead to more consistency among GNU
+utilities, so that there are fewer idiosyncracies for users to
+remember.
+
+Programs should support an option @samp{--version} which prints the
+program's version number, and an option @samp{--help} which prints
+option usage information.
+
+
+@node Documentation
+@chapter Documenting Programs
+
+Please use Texinfo for documenting GNU programs. See the Texinfo
+manual, either the hardcopy or the version in the GNU Emacs Info
+sub-system (@kbd{C-h i}).
+
+See existing GNU texinfo files (e.g. those under the @file{man/}
+directory in the GNU Emacs Distribution) for examples.
+
+The title page of the manual should state the version of the program
+which the manual applies to. The Top node of the manual should also
+contain this information. If the manual is changing more frequently
+than or independent of the program, also state a version number for
+the manual in both of these places.
+
+The manual should document all command-line arguments and all
+commands. It should give examples of their use. But don't organize
+the manual as a list of features. Instead, organize it by the
+concepts a user will have before reaching that point in the manual.
+Address the goals that a user will have in mind, and explain how to
+accomplish them.
+
+
+@node Releases
+@chapter Making Releases
+
+Package the distribution of Foo version 69.96 in a tar file named
+@file{foo-69.96.tar}. It should unpack into a subdirectory named
+@file{foo-69.96}.
+
+Building and installing the program should never modify any of the files
+contained in the distribution. This means that all the files that form
+part of the program in any way must be classified into @dfn{source
+files} and @dfn{non-source files}. Source files are written by humans
+and never changed automatically; non-source files are produced from
+source files by programs under the control of the Makefile.
+
+Naturally, all the source files must be in the distribution. It is okay
+to include non-source files in the distribution, provided they are
+up-to-date and machine-independent, so that building the distribution
+normally will never modify them. We commonly included non-source files
+produced by Bison, Lex, @TeX{}, and Makeinfo; this helps avoid
+unnecessary dependencies between our distributions, so that users can
+install whichever packages they want to install.
+
+Non-source files that might actually be modified by building and
+installing the program should @strong{never} be included in the
+distribution. So if you do distribute non-source files, always make
+sure they are up to date when you make a new distribution.
+
+Make sure that no file name in the distribution is no more than 14
+characters long. Nowadays, there are systems that adhere to a foolish
+interpretation of the POSIX standard which holds that they should refuse
+to open a longer name, rather than truncating as they did in the past.
+
+Try to make sure that all the file names will be unique on MS-DOG. A
+name on MS-DOG consists of up to 8 characters, optionally followed by a
+period and up to three characters. MS-DOG will truncate extra
+characters both before and after the period. Thus,
+@file{foobarhacker.c} and @file{foobarhacker.o} are not ambiguous; they
+are truncated to @file{foobarhac.c} and @file{foobarhac.o}, which are
+distinct.
+
+Include in your distribution a copy of the @file{texinfo.tex} you used
+to test print any @file{*.texinfo} files.
+
+@bye
projects / binutils-gdb.git / commitdiff