--- /dev/null
+This is Info file ../info/standards.info, produced by Makeinfo version
+1.68 from the input file standards.texi.
+
+START-INFO-DIR-ENTRY
+* Standards: (standards). GNU coding standards.
+END-INFO-DIR-ENTRY
+
+ GNU Coding Standards Copyright (C) 1992, 1993, 1994, 1995, 1996 Free
+Software Foundation, Inc.
+
+ 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 the Free Software Foundation.
+
+\1f
+File: standards.info, Node: CPU Portability, Next: System Functions, Prev: System Portability, Up: Writing C
+
+Portability between CPUs
+========================
+
+ Even GNU systems will differ because of differences among CPU
+types--for example, difference in byte ordering and alignment
+requirements. It is absolutely essential to handle these differences.
+However, don't make any effort to cater to the possibility that an
+`int' will be less than 32 bits. We don't support 16-bit machines in
+GNU.
+
+ Don't assume that the address of an `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:
+
+ int c;
+ ...
+ while ((c = getchar()) != EOF)
+ write(file_descriptor, &c, 1);
+
+ 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 ANSI C, so
+you can use prototypes (conditionalized to be active only in ANSI 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
+system. For example, many GNU programs have error-reporting functions
+that pass their arguments along to `printf' and friends:
+
+ error (s, a1, a2, a3)
+ char *s;
+ int a1, a2, a3;
+ {
+ fprintf (stderr, "error: ");
+ fprintf (stderr, s, a1, a2, a3);
+ }
+
+In practice, this works on all machines, and it is much simpler than any
+"correct" alternative. Be sure *not* to use a prototype for such
+functions.
+
+ However, avoid casting pointers to integers unless you really need
+to. These assumptions really 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 so, but
+you'll have to make explicit provisions to handle different word sizes.
+
+\1f
+File: standards.info, Node: System Functions, Next: Internationalization, Prev: CPU Portability, Up: Writing C
+
+Calling System Functions
+========================
+
+ C implementations differ substantially. ANSI C reduces but does not
+eliminate the incompatibilities; meanwhile, many users wish to compile
+GNU software with pre-ANSI compilers. This chapter gives
+recommendations for how to use the more or less standard C library
+functions to avoid unnecessary loss of portability.
+
+ * Don't use the value of `sprintf'. It returns the number of
+ characters written on some systems, but not on all systems.
+
+ * Don't declare system functions explicitly.
+
+ Almost any declaration for a system function is wrong on some
+ system. To minimize conflicts, leave it to the system header
+ files to declare system functions. If the headers don't declare a
+ function, let it remain undeclared.
+
+ While it may seem unclean to use a function without declaring it,
+ in practice this works fine for most system library functions on
+ the systems where this really happens; thus, the disadvantage is
+ only theoretical. By contrast, actual declarations have
+ frequently caused actual conflicts.
+
+ * If you must declare a system function, don't specify the argument
+ types. Use an old-style declaration, not an ANSI prototype. The
+ more you specify about the function, the more likely a conflict.
+
+ * In particular, don't unconditionally declare `malloc' or `realloc'.
+
+ Most GNU programs use those functions just once, in functions
+ conventionally named `xmalloc' and `xrealloc'. These functions
+ call `malloc' and `realloc', respectively, and check the results.
+
+ Because `xmalloc' and `xrealloc' are defined in your program, you
+ can declare them in other files without any risk of type conflict.
+
+ On most systems, `int' is the same length as a pointer; thus, the
+ calls to `malloc' and `realloc' work fine. For the few
+ exceptional systems (mostly 64-bit machines), you can use
+ *conditionalized* declarations of `malloc' and `realloc'--or put
+ these declarations in configuration files specific to those
+ systems.
+
+ * The string functions require special treatment. Some Unix systems
+ have a header file `string.h'; others have `strings.h'. Neither
+ file name is portable. There are two things you can do: use
+ Autoconf to figure out which file to include, or don't include
+ either file.
+
+ * 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 ANSI
+ string functions should be avoided anyway because many systems
+ still don't support them. The string functions you can use are
+ these:
+
+ strcpy strncpy strcat strncat
+ strlen strcmp strncmp
+ strchr strrchr
+
+ The copy and concatenate functions work fine without a declaration
+ as long as you don't use their values. Using their values without
+ a declaration fails on systems where the width of a pointer
+ differs from the width of `int', and perhaps in other cases. It
+ is trivial to avoid using their values, so do that.
+
+ The compare functions and `strlen' work fine without a declaration
+ on most systems, possibly all the ones that GNU software runs on.
+ You may find it necessary to declare them *conditionally* on a few
+ systems.
+
+ The search functions must be declared to return `char *'. Luckily,
+ there is no variation in the data type they return. But there is
+ variation in their names. Some systems give these functions the
+ names `index' and `rindex'; other systems use the names `strchr'
+ and `strrchr'. Some systems support both pairs of names, but
+ neither pair works on all systems.
+
+ You should pick a single pair of names and use it throughout your
+ program. (Nowadays, it is better to choose `strchr' and `strrchr'
+ for new programs, since those are the standard ANSI names.)
+ Declare both of those names as functions returning `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
+ beginning of your file (or in a header) if you want to use the
+ names `strchr' and `strrchr' throughout:
+
+ #ifndef HAVE_STRCHR
+ #define strchr index
+ #endif
+ #ifndef HAVE_STRRCHR
+ #define strrchr rindex
+ #endif
+
+ char *strchr ();
+ char *strrchr ();
+
+ Here we assume that `HAVE_STRCHR' and `HAVE_STRRCHR' are macros
+defined in systems where the corresponding functions exist. One way to
+get them properly defined is to use Autoconf.
+
+\1f
+File: standards.info, Node: Internationalization, Prev: System Functions, Up: Writing C
+
+Internationalization
+====================
+
+ 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
+in the program, and let gettext provide the way to translate them into
+other languages.
+
+ Using GNU gettext involves putting a call to the `gettext' macro
+around each string that might need translation--like this:
+
+ printf (gettext ("Processing file `%s'..."));
+
+This permits GNU gettext to replace the string `"Processing file
+`%s'..."' with a translated version.
+
+ Once a program uses gettext, please make a point of writing calls to
+`gettext' when you add new strings that call for translation.
+
+ Using GNU gettext in a package involves specifying a "text domain
+name" for the package. The text domain name is used to separate the
+translations for this package from the translations for other packages.
+Normally, the text domain name should be the same as the name of the
+package--for example, `fileutils' for the GNU file utilities.
+
+ To enable gettext to work, avoid writing code that makes assumptions
+about the structure of words. Don't construct words from parts. Here
+is an example of what not to do:
+
+ prinf ("%d file%s processed", nfiles,
+ nfiles > 1 ? "s" : "");
+
+The problem with that example is that it assumes that plurals are made
+by adding `s'. If you apply gettext to the format string, like this,
+
+ prinf (gettext ("%d file%s processed"), nfiles,
+ nfiles > 1 ? "s" : "");
+
+the message can use different words, but it will still be forced to use
+`s' for the plural. Here is a better way:
+
+ prinf ((nfiles > 1 ? "%d files processed"
+ : "%d file processed"),
+ nfiles);
+
+This way, you can apply gettext to each of the two strings
+independently:
+
+ prinf ((nfiles > 1 ? gettext ("%d files processed")
+ : gettext ("%d file processed")),
+ nfiles);
+
+This can handle any language, no matter how it forms the plural of the
+word for "file."
+
+\1f
+File: standards.info, Node: Documentation, Next: Managing Releases, Prev: Writing C, Up: Top
+
+Documenting Programs
+********************
+
+* Menu:
+
+* GNU Manuals:: Writing proper manuals.
+* Manual Structure Details:: Specific structure conventions.
+* NEWS File:: NEWS files supplement manuals.
+* Change Logs:: Recording Changes
+* Man Pages:: Man pages are secondary.
+* Reading other Manuals:: How far you can go in learning
+ from other manuals.
+
+\1f
+File: standards.info, Node: GNU Manuals, Next: Manual Structure Details, Up: Documentation
+
+GNU Manuals
+===========
+
+ The preferred way to document part of the GNU system is to write a
+manual in the Texinfo formatting language. See the Texinfo manual,
+either the hardcopy, or the on-line version available through `info' or
+the Emacs Info subsystem (`C-h i').
+
+ The manual 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 features. Instead, organize it
+logically, by subtopics. Address the goals that a user will have in
+mind, and explain how to accomplish them.
+
+ In general, a GNU manual should serve both as tutorial and reference.
+It should be set up for convenient access to each topic through Info,
+and for reading straight through (appendixes aside). A GNU manual
+should give a good introduction to a beginner reading through from the
+start, and should also provide all the details that hackers want.
+
+ That is not as hard as it first sounds. Arrange each chapter as a
+logical breakdown of its topic, but order the sections, and write their
+text, so that reading the chapter straight through makes sense. Do
+likewise when structuring the book into chapters, and when structuring a
+section into paragraphs. The watchword is, *at each point, address the
+most fundamental and important issue raised by the preceding text.*
+
+ If necessary, add extra chapters at the beginning of the manual which
+are purely tutorial and cover the basics of the subject. These provide
+the framework for a beginner to understand the rest of the manual. The
+Bison manual provides a good example of how to do this.
+
+ Don't use Unix man pages as a model for how to write GNU
+documentation; they are a bad example to follow.
+
+ Please do not use the term "pathname" that is used in Unix
+documentation; use "file name" (two words) instead. We use the term
+"path" only for search paths, which are lists of file names.
+
+\1f
+File: standards.info, Node: Manual Structure Details, Next: NEWS File, Prev: GNU Manuals, Up: Documentation
+
+Manual Structure Details
+========================
+
+ The title page of the manual should state the version of the program
+to which the manual applies. 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 have a node named `PROGRAM Invocation' or
+`Invoking PROGRAM', where PROGRAM stands for the name of the program
+being described, as you would type it in the shell to run the program.
+This node (together with its subnodes, if any) should describe the
+program's command line arguments and how to run it (the sort of
+information people would look in a man page for). Start with an
+`@example' containing a template for all the options and arguments that
+the program uses.
+
+ Alternatively, put a menu item in some menu whose item name fits one
+of 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.
+
+ If one manual describes several programs, it should have such a node
+for each program described.
+
+\1f
+File: standards.info, Node: NEWS File, Next: Change Logs, Prev: Manual Structure Details, Up: Documentation
+
+The NEWS File
+=============
+
+ In addition to its manual, the package should have a file named
+`NEWS' which contains a list of user-visible changes worth mentioning.
+In each new release, add items to the front of the file and identify
+the version they pertain to. Don't discard old items; leave them in
+the file after the newer items. This way, a user upgrading from any
+previous version can see what is new.
+
+ If the `NEWS' file gets very long, move some of the older items into
+a file named `ONEWS' and put a note at the end referring the user to
+that file.
+
+\1f
+File: standards.info, Node: Change Logs, Next: Man Pages, Prev: NEWS File, Up: Documentation
+
+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
+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.
+
+ A change log file is normally called `ChangeLog' and covers an
+entire directory. Each directory can have its own change log, or a
+directory can use the change log of its parent directory-it's up to you.
+
+ Another alternative is to record change log information with a
+version control system such as RCS or CVS. This can be converted
+automatically to a `ChangeLog' file.
+
+ The easiest way to add an entry to `ChangeLog' is with the Emacs
+command `M-x add-change-log-entry'. 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:
+
+ * 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.
+
+ It's important to name the changed function or variable in full.
+Don't abbreviate function or variable names, and don't combine them.
+Subsequent maintainers will often search for a function name to find
+all the change log entries that pertain to it; if you abbreviate the
+name, they won't find it when they search. For example, some people
+are tempted to abbreviate groups of function names by writing `*
+register.el ({insert,jump-to}-register)'; this is not a good idea,
+since searching for `jump-to-register' or `insert-register' would not
+find the entry.
+
+ There's no need to describe the full purpose of the changes or how
+they work together. It is better to put such explanations 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.
+
+ You can think of the change log as a conceptual "undo list" which
+explains how earlier versions were different from the current version.
+People can see the current version; they don't need the change log to
+tell them what is in it. What they want from a change log is a clear
+explanation of how the earlier version differed.
+
+ 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 make change log entries 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; it is enough to compare the
+passage with the way the program actually works.
+
+\1f
+File: standards.info, Node: Man Pages, Next: Reading other Manuals, Prev: Change Logs, Up: Documentation
+
+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.
+It's your choice whether to include a man page in your program.
+
+ When you make this decision, consider that supporting a man page
+requires continual effort each time the program is changed. The time
+you spend on the man page is time taken away from more useful work.
+
+ For a simple program which changes little, updating the man page may
+be a small job. Then there is little reason not to include a man page,
+if you have one.
+
+ For a large program that changes a great deal, updating a man page
+may be a substantial burden. If a user offers to donate a man page,
+you may find this gift costly to accept. It may be better to refuse
+the man page unless the same person agrees to take full responsibility
+for maintaining it--so that you can wash your hands of it entirely. If
+this volunteer later ceases to do the job, then don't feel obliged to
+pick it up yourself; it may be better to withdraw the man page from the
+distribution until someone else agrees to update it.
+
+ When a program changes only a little, you may feel that the
+discrepancies are small enough that the man page remains useful without
+updating. If so, put a prominent note near the beginning of the man
+page explaining that you don't maintain it and that the Texinfo manual
+is more authoritative. The note should say how to access the Texinfo
+documentation.
+
+\1f
+File: standards.info, Node: Reading other Manuals, Prev: Man Pages, Up: Documentation
+
+Reading other Manuals
+=====================
+
+ There may be non-free books or documentation files that describe the
+program you are documenting.
+
+ It is ok to use these documents for reference, just as the author of
+a new algebra textbook can read other books on algebra. A large portion
+of any non-fiction book consists of facts, in this case facts about how
+a certain program works, and these facts are necessarily the same for
+everyone who writes about the subject. But be careful not to copy your
+outline structure, wording, tables or examples from preexisting non-free
+documentation. Copying from free documentation may be ok; please check
+with the FSF about the individual case.
+
+\1f
+File: standards.info, Node: Managing Releases, Prev: Documentation, Up: Top
+
+The Release Process
+*******************
+
+ 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
+that it can be configured to run on a variety of systems. Your Makefile
+should conform to the GNU standards described below, and your directory
+layout should also conform to the standards discussed below. Doing so
+makes it easy to include your package into the larger framework of all
+GNU software.
+
+* Menu:
+
+* Configuration:: How Configuration Should Work
+* Makefile Conventions:: Makefile Conventions
+* Releases:: Making Releases
+
+\1f
+File: standards.info, Node: Configuration, Next: Makefile Conventions, Up: Managing Releases
+
+How Configuration Should Work
+=============================
+
+ Each GNU distribution should come with a shell script named
+`configure'. This script is given arguments which describe the kind of
+machine and system you want to compile the program for.
+
+ The `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
+`config.h' to the proper configuration file for the chosen system. If
+you use this technique, the distribution should *not* contain a file
+named `config.h'. This is so that people won't be able to build the
+program without configuring it first.
+
+ Another thing that `configure' can do is to edit the Makefile. If
+you do this, the distribution should *not* contain a file named
+`Makefile'. Instead, it should include a 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 `configure' does write the `Makefile', then `Makefile' should
+have a target named `Makefile' which causes `configure' to be rerun,
+setting up the same configuration that was set up last time. The files
+that `configure' reads should be listed as dependencies of `Makefile'.
+
+ All the files which are output from the `configure' script should
+have comments at the beginning explaining that they were generated
+automatically using `configure'. This is so that users won't think of
+trying to edit them by hand.
+
+ The `configure' script should write a file named `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 `configure' script should accept an option of the form
+`--srcdir=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 `--srcdir', then `configure' should
+check both `.' and `..' 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 `--srcdir' is by editing a
+definition of `VPATH' into the Makefile. Some rules may need to refer
+explicitly to the specified source directory. To make this possible,
+`configure' can add to the Makefile a variable named `srcdir' whose
+value is precisely the specified directory.
+
+ The `configure' script should also take an argument which specifies
+the type of system to build the program for. This argument should look
+like this:
+
+ CPU-COMPANY-SYSTEM
+
+ For example, a Sun 3 might be `m68k-sun-sunos4.1'.
+
+ The `configure' script needs to be able to decode all plausible
+alternatives for how to describe a machine. Thus, `sun3-sunos4.1'
+would be a valid alias. For many programs, `vax-dec-ultrix' would be
+an alias for `vax-dec-bsd', simply because the differences between
+Ultrix and BSD are rarely noticeable, but a few programs might need to
+distinguish them.
+
+ There is a shell script called `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 present on the machine, and include or exclude optional
+parts of the package:
+
+`--enable-FEATURE[=PARAMETER]'
+ Configure the package to build and install an optional user-level
+ facility called FEATURE. This allows users to choose which
+ optional features to include. Giving an optional PARAMETER of
+ `no' should omit FEATURE, if it is built by default.
+
+ No `--enable' option should *ever* cause one feature to replace
+ another. No `--enable' option should ever substitute one useful
+ behavior for another useful behavior. The only proper use for
+ `--enable' is for questions of whether to build part of the program
+ or exclude it.
+
+`--with-PACKAGE'
+ The package PACKAGE will be installed, so configure this package
+ to work with PACKAGE.
+
+ Possible values of PACKAGE include `x', `x-toolkit', `gnu-as' (or
+ `gas'), `gnu-ld', `gnu-libc', and `gdb'.
+
+ Do not use a `--with' option to specify the file name to use to
+ find certain files. That is outside the scope of what `--with'
+ options are for.
+
+`--nfp'
+ The target machine has no floating point processor.
+
+`--gas'
+ The target machine assembler is GAS, the GNU assembler. This is
+ obsolete; users should use `--with-gnu-as' instead.
+
+`--x'
+ The target machine has the X Window System installed. This is
+ obsolete; users should use `--with-x' instead.
+
+ All `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
+`--with-' or `--enable-'. This is so users will be able to configure
+an entire GNU source tree at once with a single set of options.
+
+ You will note that the categories `--with-' and `--enable-' are
+narrow: they *do not* provide a place for any sort of option you might
+think of. That is deliberate. We want to limit the possible
+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 `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 `--host=HOSTTYPE' when running
+`configure'. This specifies the host system without changing the type
+of target system. The syntax for HOSTTYPE is the same as described
+above.
+
+ Bootstrapping a cross-compiler requires compiling it on a machine
+other than the host it will run on. Compilation packages accept a
+configuration option `--build=HOSTTYPE' for specifying the
+configuration on which you will compile them, in case that is different
+from the host.
+
+ Programs for which cross-operation is not meaningful need not accept
+the `--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 `configure' script can simply
+ignore most of its arguments.
+
+\1f
+File: standards.info, Node: Makefile Conventions, Next: Releases, Prev: Configuration, Up: Managing Releases
+
+Makefile Conventions
+====================
+
+ This node describes conventions for writing the Makefiles for GNU
+programs.
+
+* Menu:
+
+* Makefile Basics:: General Conventions for Makefiles
+* Utilities in Makefiles:: Utilities in Makefiles
+* Command Variables:: Variables for Specifying Commands
+* Directory Variables:: Variables for Installation Directories
+* Standard Targets:: Standard Targets for Users
+
+\1f
+File: standards.info, Node: Makefile Basics, Next: Utilities in Makefiles, Up: Makefile Conventions
+
+General Conventions for Makefiles
+---------------------------------
+
+ Every Makefile should contain this line:
+
+ SHELL = /bin/sh
+
+to avoid trouble on systems where the `SHELL' variable might be
+inherited from the environment. (This is never a problem with GNU
+`make'.)
+
+ Different `make' programs have incompatible suffix lists and
+implicit rules, and this sometimes creates confusion or misbehavior. So
+it is a good idea to set the suffix list explicitly using only the
+suffixes you need in the particular Makefile, like this:
+
+ .SUFFIXES:
+ .SUFFIXES: .c .o
+
+The first line clears out the suffix list, the second introduces all
+suffixes which may be subject to implicit rules in this Makefile.
+
+ Don't assume that `.' is in the path for command execution. When
+you need to run programs that are a part of your package during the
+make, please make sure that it uses `./' if the program is built as
+part of the make or `$(srcdir)/' if the file is an unchanging part of
+the source code. Without one of these prefixes, the current search
+path is used.
+
+ The distinction between `./' and `$(srcdir)/' is important when
+using the `--srcdir' option to `configure'. A rule of the form:
+
+ foo.1 : foo.man sedscript
+ sed -e sedscript foo.man > foo.1
+
+will fail when the current directory is not the source directory,
+because `foo.man' and `sedscript' are not in the current directory.
+
+ When using GNU `make', relying on `VPATH' to find the source file
+will work in the case where there is a single dependency file, since
+the `make' automatic variable `$<' will represent the source file
+wherever it is. (Many versions of `make' set `$<' only in implicit
+rules.) A Makefile target like
+
+ foo.o : bar.c
+ $(CC) -I. -I$(srcdir) $(CFLAGS) -c bar.c -o foo.o
+
+should instead be written as
+
+ foo.o : bar.c
+ $(CC) -I. -I$(srcdir) $(CFLAGS) -c $< -o $@
+
+in order to allow `VPATH' to work correctly. When the target has
+multiple dependencies, using an explicit `$(srcdir)' is the easiest way
+to make the rule work well. For example, the target above for `foo.1'
+is best written as:
+
+ foo.1 : foo.man sedscript
+ sed -e $(srcdir)/sedscript $(srcdir)/foo.man > $@
+
+ Try to make the build and installation targets, at least (and all
+their subtargets) work correctly with a parallel `make'.
+
+\1f
+File: standards.info, Node: Utilities in Makefiles, Next: Command Variables, Prev: Makefile Basics, Up: Makefile Conventions
+
+Utilities in Makefiles
+----------------------
+
+ Write the Makefile commands (and any shell scripts, such as
+`configure') to run in `sh', not in `csh'. Don't use any special
+features of `ksh' or `bash'.
+
+ The `configure' script and the Makefile rules for building and
+installation should not use any utilities directly except these:
+
+ cat cmp cp echo egrep expr false grep
+ ln mkdir mv pwd rm rmdir sed test touch true
+
+ Stick to the generally supported options for these programs. For
+example, don't use `mkdir -p', convenient as it may be, because most
+systems don't support it.
+
+ It is a good idea to avoid creating symbolic links in makefiles,
+since a few systems don't support them.
+
+ The Makefile rules for building and installation can also use
+compilers and related programs, but should do so via `make' variables
+so that the user can substitute alternatives. Here are some of the
+programs we mean:
+
+ ar bison cc flex install ld lex
+ make makeinfo ranlib texi2dvi yacc
+
+ Use the following `make' variables:
+
+ $(AR) $(BISON) $(CC) $(FLEX) $(INSTALL) $(LD) $(LEX)
+ $(MAKE) $(MAKEINFO) $(RANLIB) $(TEXI2DVI) $(YACC)
+
+ When you use `ranlib', you should make sure nothing bad happens if
+the system does not have `ranlib'. Arrange to ignore an error from
+that command, and print a message before the command to tell the user
+that failure of the `ranlib' command does not mean a problem. (The
+Autoconf `AC_PROG_RANLIB' macro can help with this.)
+
+ If you use symbolic links, you should implement a fallback for
+systems that don't have symbolic links.
+
+ It is ok to use other utilities in Makefile portions (or scripts)
+intended only for particular systems where you know those utilities
+exist.
+
+\1f
+File: standards.info, Node: Command Variables, Next: Directory Variables, Prev: Utilities in Makefiles, Up: Makefile Conventions
+
+Variables for Specifying Commands
+---------------------------------
+
+ Makefiles should provide variables for overriding certain commands,
+options, and so on.
+
+ In particular, you should run most utility programs via variables.
+Thus, if you use Bison, have a variable named `BISON' whose default
+value is set with `BISON = bison', and refer to it with `$(BISON)'
+whenever you need to use Bison.
+
+ File management utilities such as `ln', `rm', `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.
+
+ Each program-name variable should come with an options variable that
+is used to supply options to the program. Append `FLAGS' to the
+program-name variable name to get the options variable name--for
+example, `BISONFLAGS'. (The name `CFLAGS' is an exception to this
+rule, but we keep it because it is standard.) Use `CPPFLAGS' in any
+compilation command that runs the preprocessor, and use `LDFLAGS' in
+any compilation command that does linking as well as in any direct use
+of `ld'.
+
+ If there are C compiler options that *must* be used for proper
+compilation of certain files, do not include them in `CFLAGS'. Users
+expect to be able to specify `CFLAGS' freely themselves. Instead,
+arrange to pass the necessary options to the C compiler independently
+of `CFLAGS', by writing them explicitly in the compilation commands or
+by defining an implicit rule, like this:
+
+ CFLAGS = -g
+ ALL_CFLAGS = -I. $(CFLAGS)
+ .c.o:
+ $(CC) -c $(CPPFLAGS) $(ALL_CFLAGS) $<
+
+ Do include the `-g' option in `CFLAGS', because that is not
+*required* for proper compilation. You can consider it a default that
+is only recommended. If the package is set up so that it is compiled
+with GCC by default, then you might as well include `-O' in the default
+value of `CFLAGS' as well.
+
+ Put `CFLAGS' last in the compilation command, after other variables
+containing compiler options, so the user can use `CFLAGS' to override
+the others.
+
+ Every Makefile should define the variable `INSTALL', which is the
+basic command for installing a file into the system.
+
+ Every Makefile should also define the variables `INSTALL_PROGRAM'
+and `INSTALL_DATA'. (The default for each of these should be
+`$(INSTALL)'.) Then it should use those variables as the commands for
+actual installation, for executables and nonexecutables respectively.
+Use these variables as follows:
+
+ $(INSTALL_PROGRAM) foo $(bindir)/foo
+ $(INSTALL_DATA) libfoo.a $(libdir)/libfoo.a
+
+Always use a file name, not a directory name, as the second argument of
+the installation commands. Use a separate command for each file to be
+installed.
+
+\1f
+File: standards.info, Node: Directory Variables, Next: Standard Targets, Prev: Command Variables, Up: Makefile Conventions
+
+Variables for Installation Directories
+--------------------------------------
+
+ Installation directories should always be named by variables, so it
+is easy to install in a nonstandard place. The standard names for these
+variables are described below. They are based on a standard filesystem
+layout; variants of it are used in SVR4, 4.4BSD, Linux, Ultrix v4, and
+other modern operating systems.
+
+ These two variables set the root for the installation. All the other
+installation directories should be subdirectories of one of these two,
+and nothing should be directly installed into these two directories.
+
+`prefix'
+ A prefix used in constructing the default values of the variables
+ listed below. The default value of `prefix' should be
+ `/usr/local'. When building the complete GNU system, the prefix
+ will be empty and `/usr' will be a symbolic link to `/'. (If you
+ are using Autoconf, write it as `@prefix@'.)
+
+`exec_prefix'
+ A prefix used in constructing the default values of some of the
+ variables listed below. The default value of `exec_prefix' should
+ be `$(prefix)'. (If you are using Autoconf, write it as
+ `@exec_prefix@'.)
+
+ Generally, `$(exec_prefix)' is used for directories that contain
+ machine-specific files (such as executables and subroutine
+ libraries), while `$(prefix)' is used directly for other
+ directories.
+
+ Executable programs are installed in one of the following
+directories.
+
+`bindir'
+ The directory for installing executable programs that users can
+ run. This should normally be `/usr/local/bin', but write it as
+ `$(exec_prefix)/bin'. (If you are using Autoconf, write it as
+ `@bindir@'.)
+
+`sbindir'
+ The directory for installing executable programs that can be run
+ from the shell, but are only generally useful to system
+ administrators. This should normally be `/usr/local/sbin', but
+ write it as `$(exec_prefix)/sbin'. (If you are using Autoconf,
+ write it as `@sbindir@'.)
+
+`libexecdir'
+ The directory for installing executable programs to be run by other
+ programs rather than by users. This directory should normally be
+ `/usr/local/libexec', but write it as `$(exec_prefix)/libexec'.
+ (If you are using Autoconf, write it as `@libexecdir@'.)
+
+ Data files used by the program during its execution are divided into
+categories in two ways.
+
+ * Some files are normally modified by programs; others are never
+ normally modified (though users may edit some of these).
+
+ * Some files are architecture-independent and can be shared by all
+ machines at a site; some are architecture-dependent and can be
+ shared only by machines of the same kind and operating system;
+ others may never be shared between two machines.
+
+ This makes for six different possibilities. However, we want to
+discourage the use of architecture-dependent files, aside from object
+files and libraries. It is much cleaner to make other data files
+architecture-independent, and it is generally not hard.
+
+ Therefore, here are the variables Makefiles should use to specify
+directories:
+
+`datadir'
+ The directory for installing read-only architecture independent
+ data files. This should normally be `/usr/local/share', but write
+ it as `$(prefix)/share'. (If you are using Autoconf, write it as
+ `@datadir@'.) As a special exception, see `$(infodir)' and
+ `$(includedir)' below.
+
+`sysconfdir'
+ The directory for installing read-only data files that pertain to a
+ single machine-that is to say, files for configuring a host.
+ Mailer and network configuration files, `/etc/passwd', and so
+ forth belong here. All the files in this directory should be
+ ordinary ASCII text files. This directory should normally be
+ `/usr/local/etc', but write it as `$(prefix)/etc'. (If you are
+ using Autoconf, write it as `@sysconfdir@'.)
+
+ Do not install executables in this directory (they probably belong
+ in `$(libexecdir)' or `$(sbindir)'). Also do not install files
+ that are modified in the normal course of their use (programs
+ whose purpose is to change the configuration of the system
+ excluded). Those probably belong in `$(localstatedir)'.
+
+`sharedstatedir'
+ The directory for installing architecture-independent data files
+ which the programs modify while they run. This should normally be
+ `/usr/local/com', but write it as `$(prefix)/com'. (If you are
+ using Autoconf, write it as `@sharedstatedir@'.)
+
+`localstatedir'
+ The directory for installing data files which the programs modify
+ while they run, and that pertain to one specific machine. Users
+ should never need to modify files in this directory to configure
+ the package's operation; put such configuration information in
+ separate files that go in `$(datadir)' or `$(sysconfdir)'.
+ `$(localstatedir)' should normally be `/usr/local/var', but write
+ it as `$(prefix)/var'. (If you are using Autoconf, write it as
+ `@localstatedir@'.)
+
+`libdir'
+ The directory for object files and libraries of object code. Do
+ not install executables here, they probably ought to go in
+ `$(libexecdir)' instead. The value of `libdir' should normally be
+ `/usr/local/lib', but write it as `$(exec_prefix)/lib'. (If you
+ are using Autoconf, write it as `@libdir@'.)
+
+`infodir'
+ The directory for installing the Info files for this package. By
+ default, it should be `/usr/local/info', but it should be written
+ as `$(prefix)/info'. (If you are using Autoconf, write it as
+ `@infodir@'.)
+
+`includedir'
+ The directory for installing header files to be included by user
+ programs with the C `#include' preprocessor directive. This
+ should normally be `/usr/local/include', but write it as
+ `$(prefix)/include'. (If you are using Autoconf, write it as
+ `@includedir@'.)
+
+ Most compilers other than GCC do not look for header files in
+ `/usr/local/include'. So installing the header files this way is
+ only useful with GCC. Sometimes this is not a problem because some
+ libraries are only really intended to work with GCC. But some
+ libraries are intended to work with other compilers. They should
+ install their header files in two places, one specified by
+ `includedir' and one specified by `oldincludedir'.
+
+`oldincludedir'
+ The directory for installing `#include' header files for use with
+ compilers other than GCC. This should normally be `/usr/include'.
+ (If you are using Autoconf, you can write it as `@oldincludedir@'.)
+
+ The Makefile commands should check whether the value of
+ `oldincludedir' is empty. If it is, they should not try to use
+ it; they should cancel the second installation of the header files.
+
+ A package should not replace an existing header in this directory
+ unless the header came from the same package. Thus, if your Foo
+ package provides a header file `foo.h', then it should install the
+ header file in the `oldincludedir' directory if either (1) there
+ is no `foo.h' there or (2) the `foo.h' that exists came from the
+ Foo package.
+
+ To tell whether `foo.h' came from the Foo package, put a magic
+ string in the file--part of a comment--and `grep' for that string.
+
+ Unix-style man pages are installed in one of the following:
+
+`mandir'
+ The top-level directory for installing the man pages (if any) for
+ this package. It will normally be `/usr/local/man', but you should
+ write it as `$(prefix)/man'. (If you are using Autoconf, write it
+ as `@mandir@'.)
+
+`man1dir'
+ The directory for installing section 1 man pages. Write it as
+ `$(mandir)/man1'.
+
+`man2dir'
+ The directory for installing section 2 man pages. Write it as
+ `$(mandir)/man2'
+
+`...'
+ *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.*
+
+`manext'
+ The file name extension for the installed man page. This should
+ contain a period followed by the appropriate digit; it should
+ normally be `.1'.
+
+`man1ext'
+ The file name extension for installed section 1 man pages.
+
+`man2ext'
+ The file name extension for installed section 2 man pages.
+
+`...'
+ Use these names instead of `manext' if the package needs to
+ install man pages in more than one section of the manual.
+
+ And finally, you should set the following variable:
+
+`srcdir'
+ The directory for the sources being compiled. The value of this
+ variable is normally inserted by the `configure' shell script.
+ (If you are using Autconf, use `srcdir = @srcdir@'.)
+
+ For example:
+
+ # Common prefix for installation directories.
+ # NOTE: This directory must exist when you start the install.
+ prefix = /usr/local
+ exec_prefix = $(prefix)
+ # Where to put the executable for the command `gcc'.
+ bindir = $(exec_prefix)/bin
+ # Where to put the directories used by the compiler.
+ libexecdir = $(exec_prefix)/libexec
+ # Where to put the Info files.
+ infodir = $(prefix)/info
+
+ If your program installs a large number of files into one of the
+standard user-specified directories, it might be useful to group them
+into a subdirectory particular to that program. If you do this, you
+should write the `install' rule to create these subdirectories.
+
+ Do not expect the user to include the subdirectory name in the value
+of any of the variables listed above. The idea of having a uniform set
+of variable names for installation directories is to enable the user to
+specify the exact same values for several different GNU packages. In
+order for this to be useful, all the packages must be designed so that
+they will work sensibly when the user does so.
+
projects / chise / xemacs-chise.git.1 / blobdiff