+++ /dev/null
-This is configure.info, produced by makeinfo version 4.8 from
-.././etc/configure.texi.
-
-INFO-DIR-SECTION GNU admin
-START-INFO-DIR-ENTRY
-* configure: (configure). The GNU configure and build system
-END-INFO-DIR-ENTRY
-
- This file documents the GNU configure and build system.
-
- Copyright (C) 1998 Cygnus Solutions.
-
- 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 Foundation.
-
-\1f
-File: configure.info, Node: Top, Next: Introduction, Up: (dir)
-
-GNU configure and build system
-******************************
-
-The GNU configure and build system.
-
-* Menu:
-
-* Introduction:: Introduction.
-* Getting Started:: Getting Started.
-* Files:: Files.
-* Configuration Names:: Configuration Names.
-* Cross Compilation Tools:: Cross Compilation Tools.
-* Canadian Cross:: Canadian Cross.
-* Cygnus Configure:: Cygnus Configure.
-* Multilibs:: Multilibs.
-* FAQ:: Frequently Asked Questions.
-* Index:: Index.
-
-\1f
-File: configure.info, Node: Introduction, Next: Getting Started, Prev: Top, Up: Top
-
-1 Introduction
-**************
-
-This document describes the GNU configure and build systems. It
-describes how autoconf, automake, libtool, and make fit together. It
-also includes a discussion of the older Cygnus configure system.
-
- This document does not describe in detail how to use each of the
-tools; see the respective manuals for that. Instead, it describes
-which files the developer must write, which files are machine generated
-and how they are generated, and where certain common problems should be
-addressed.
-
- This document draws on several sources, including the autoconf
-manual by David MacKenzie (*note autoconf overview: (autoconf)Top.),
-the automake manual by David MacKenzie and Tom Tromey (*note automake
-overview: (automake)Top.), the libtool manual by Gordon Matzigkeit
-(*note libtool overview: (libtool)Top.), and the Cygnus configure
-manual by K. Richard Pixley.
-
-* Menu:
-
-* Goals:: Goals.
-* Tools:: The tools.
-* History:: History.
-* Building:: Building.
-
-\1f
-File: configure.info, Node: Goals, Next: Tools, Up: Introduction
-
-1.1 Goals
-=========
-
-The GNU configure and build system has two main goals.
-
- The first is to simplify the development of portable programs. The
-system permits the developer to concentrate on writing the program,
-simplifying many details of portability across Unix and even Windows
-systems, and permitting the developer to describe how to build the
-program using simple rules rather than complex Makefiles.
-
- The second is to simplify the building of programs distributed as
-source code. All programs are built using a simple, standardized, two
-step process. The program builder need not install any special tools in
-order to build the program.
-
-\1f
-File: configure.info, Node: Tools, Next: History, Prev: Goals, Up: Introduction
-
-1.2 Tools
-=========
-
-The GNU configure and build system is comprised of several different
-tools. Program developers must build and install all of these tools.
-
- People who just want to build programs from distributed sources
-normally do not need any special tools beyond a Unix shell, a make
-program, and a C compiler.
-
-autoconf
- provides a general portability framework, based on testing the
- features of the host system at build time.
-
-automake
- a system for describing how to build a program, permitting the
- developer to write a simplified `Makefile'.
-
-libtool
- a standardized approach to building shared libraries.
-
-gettext
- provides a framework for translation of text messages into other
- languages; not really discussed in this document.
-
-m4
- autoconf requires the GNU version of m4; the standard Unix m4 does
- not suffice.
-
-perl
- automake requires perl.
-
-\1f
-File: configure.info, Node: History, Next: Building, Prev: Tools, Up: Introduction
-
-1.3 History
-===========
-
-This is a very brief and probably inaccurate history.
-
- As the number of Unix variants increased during the 1980s, it became
-harder to write programs which could run on all variants. While it was
-often possible to use `#ifdef' to identify particular systems,
-developers frequently did not have access to every system, and the
-characteristics of some systems changed from version to version.
-
- By 1992, at least three different approaches had been developed:
- * The Metaconfig program, by Larry Wall, Harlan Stenn, and Raphael
- Manfredi.
-
- * The Cygnus configure script, by K. Richard Pixley, and the gcc
- configure script, by Richard Stallman. These use essentially the
- same approach, and the developers communicated regularly.
-
- * The autoconf program, by David MacKenzie.
-
- The Metaconfig program is still used for Perl and a few other
-programs. It is part of the Dist package. I do not know if it is
-being developed.
-
- In 1994, David MacKenzie and others modified autoconf to incorporate
-all the features of Cygnus configure. Since then, there has been a
-slow but steady conversion of GNU programs from Cygnus configure to
-autoconf. gcc has been converted, eliminating the gcc configure script.
-
- GNU autoconf was regularly maintained until late 1996. As of this
-writing in June, 1998, it has no public maintainer.
-
- Most programs are built using the make program, which requires the
-developer to write Makefiles describing how to build the programs.
-Since most programs are built in pretty much the same way, this led to a
-lot of duplication.
-
- The X Window system is built using the imake tool, which uses a
-database of rules to eliminate the duplication. However, building a
-tool which was developed using imake requires that the builder have
-imake installed, violating one of the goals of the GNU system.
-
- The new BSD make provides a standard library of Makefile fragments,
-which permits developers to write very simple Makefiles. However, this
-requires that the builder install the new BSD make program.
-
- In 1994, David MacKenzie wrote the first version of automake, which
-permitted writing a simple build description which was converted into a
-Makefile which could be used by the standard make program. In 1995, Tom
-Tromey completely rewrote automake in Perl, and he continues to enhance
-it.
-
- Various free packages built libraries, and by around 1995 several
-included support to build shared libraries on various platforms.
-However, there was no consistent approach. In early 1996, Gordon
-Matzigkeit began working on libtool, which provided a standardized
-approach to building shared libraries. This was integrated into
-automake from the start.
-
- The development of automake and libtool was driven by the GNITS
-project, a group of GNU maintainers who designed standardized tools to
-help meet the GNU coding standards.
-
-\1f
-File: configure.info, Node: Building, Prev: History, Up: Introduction
-
-1.4 Building
-============
-
-Most readers of this document should already know how to build a tool by
-running `configure' and `make'. This section may serve as a quick
-introduction or reminder.
-
- Building a tool is normally as simple as running `configure'
-followed by `make'. You should normally run `configure' from an empty
-directory, using some path to refer to the `configure' script in the
-source directory. The directory in which you run `configure' is called
-the "object directory".
-
- In order to use a object directory which is different from the source
-directory, you must be using the GNU version of `make', which has the
-required `VPATH' support. Despite this restriction, using a different
-object directory is highly recommended:
- * It keeps the files generated during the build from cluttering up
- your sources.
-
- * It permits you to remove the built files by simply removing the
- entire build directory.
-
- * It permits you to build from the same sources with several sets of
- configure options simultaneously.
-
- If you don't have GNU `make', you will have to run `configure' in
-the source directory. All GNU packages should support this; in
-particular, GNU packages should not assume the presence of GNU `make'.
-
- After running `configure', you can build the tools by running `make'.
-
- To install the tools, run `make install'. Installing the tools will
-copy the programs and any required support files to the "installation
-directory". The location of the installation directory is controlled
-by `configure' options, as described below.
-
- In the Cygnus tree at present, the info files are built and
-installed as a separate step. To build them, run `make info'. To
-install them, run `make install-info'. The equivalent html files are
-also built and installed in a separate step. To build the html files,
-run `make html'. To install the html files run `make install-html'.
-
- All `configure' scripts support a wide variety of options. The most
-interesting ones are `--with' and `--enable' options which are
-generally specific to particular tools. You can usually use the
-`--help' option to get a list of interesting options for a particular
-configure script.
-
- The only generic options you are likely to use are the `--prefix'
-and `--exec-prefix' options. These options are used to specify the
-installation directory.
-
- The directory named by the `--prefix' option will hold machine
-independent files such as info files.
-
- The directory named by the `--exec-prefix' option, which is normally
-a subdirectory of the `--prefix' directory, will hold machine dependent
-files such as executables.
-
- The default for `--prefix' is `/usr/local'. The default for
-`--exec-prefix' is the value used for `--prefix'.
-
- The convention used in Cygnus releases is to use a `--prefix' option
-of `/usr/cygnus/RELEASE', where RELEASE is the name of the release, and
-to use a `--exec-prefix' option of `/usr/cygnus/RELEASE/H-HOST', where
-HOST is the configuration name of the host system (*note Configuration
-Names::).
-
- Do not use either the source or the object directory as the
-installation directory. That will just lead to confusion.
-
-\1f
-File: configure.info, Node: Getting Started, Next: Files, Prev: Introduction, Up: Top
-
-2 Getting Started
-*****************
-
-To start using the GNU configure and build system with your software
-package, you must write three files, and you must run some tools to
-manually generate additional files.
-
-* Menu:
-
-* Write configure.in:: Write configure.in.
-* Write Makefile.am:: Write Makefile.am.
-* Write acconfig.h:: Write acconfig.h.
-* Generate files:: Generate files.
-* Getting Started Example:: Example.
-
-\1f
-File: configure.info, Node: Write configure.in, Next: Write Makefile.am, Up: Getting Started
-
-2.1 Write configure.in
-======================
-
-You must first write the file `configure.in'. This is an autoconf
-input file, and the autoconf manual describes in detail what this file
-should look like.
-
- You will write tests in your `configure.in' file to check for
-conditions that may change from one system to another, such as the
-presence of particular header files or functions.
-
- For example, not all systems support the `gettimeofday' function.
-If you want to use the `gettimeofday' function when it is available,
-and to use some other function when it is not, you would check for this
-by putting `AC_CHECK_FUNCS(gettimeofday)' in `configure.in'.
-
- When the configure script is run at build time, this will arrange to
-define the preprocessor macro `HAVE_GETTIMEOFDAY' to the value 1 if the
-`gettimeofday' function is available, and to not define the macro at
-all if the function is not available. Your code can then use `#ifdef'
-to test whether it is safe to call `gettimeofday'.
-
- If you have an existing body of code, the `autoscan' program may
-help identify potential portability problems, and hence configure tests
-that you will want to use. *Note Invoking autoscan: (autoconf)Invoking
-autoscan.
-
- Another handy tool for an existing body of code is `ifnames'. This
-will show you all the preprocessor conditionals that the code already
-uses. *Note Invoking ifnames: (autoconf)Invoking ifnames.
-
- Besides the portability tests which are specific to your particular
-package, every `configure.in' file should contain the following macros.
-
-`AC_INIT'
- This macro takes a single argument, which is the name of a file in
- your package. For example, `AC_INIT(foo.c)'.
-
-`AC_PREREQ(VERSION)'
- This macro is optional. It may be used to indicate the version of
- `autoconf' that you are using. This will prevent users from
- running an earlier version of `autoconf' and perhaps getting an
- invalid `configure' script. For example, `AC_PREREQ(2.12)'.
-
-`AM_INIT_AUTOMAKE'
- This macro takes two arguments: the name of the package, and a
- version number. For example, `AM_INIT_AUTOMAKE(foo, 1.0)'. (This
- macro is not needed if you are not using automake).
-
-`AM_CONFIG_HEADER'
- This macro names the header file which will hold the preprocessor
- macro definitions at run time. Normally this should be
- `config.h'. Your sources would then use `#include "config.h"' to
- include it.
-
- This macro may optionally name the input file for that header
- file; by default, this is `config.h.in', but that file name works
- poorly on DOS filesystems. Therefore, it is often better to name
- it explicitly as `config.in'.
-
- This is what you should normally put in `configure.in':
- AM_CONFIG_HEADER(config.h:config.in)
-
- (If you are not using automake, use `AC_CONFIG_HEADER' rather than
- `AM_CONFIG_HEADER').
-
-`AM_MAINTAINER_MODE'
- This macro always appears in Cygnus configure scripts. Other
- programs may or may not use it.
-
- If this macro is used, the `--enable-maintainer-mode' option is
- required to enable automatic rebuilding of generated files used by
- the configure system. This of course requires that developers be
- aware of, and use, that option.
-
- If this macro is not used, then the generated files will always be
- rebuilt automatically. This will cause problems if the wrong
- versions of autoconf, automake, or others are in the builder's
- `PATH'.
-
- (If you are not using automake, you do not need to use this macro).
-
-`AC_EXEEXT'
- Either this macro or `AM_EXEEXT' always appears in Cygnus configure
- files. Other programs may or may not use one of them.
-
- This macro looks for the executable suffix used on the host
- system. On Unix systems, this is the empty string. On Windows
- systems, this is `.exe'. This macro directs automake to use the
- executable suffix as appropriate when creating programs. This
- macro does not take any arguments.
-
- The `AC_EXEEXT' form is new, and is part of a Cygnus patch to
- autoconf to support compiling with Visual C++. Older programs use
- `AM_EXEEXT' instead.
-
- (Programs which do not use automake use neither `AC_EXEEXT' nor
- `AM_EXEEXT').
-
-`AC_PROG_CC'
- If you are writing C code, you will normally want to use this
- macro. It locates the C compiler to use. It does not take any
- arguments.
-
- However, if this `configure.in' file is for a library which is to
- be compiled by a cross compiler which may not fully work, then you
- will not want to use `AC_PROG_CC'. Instead, you will want to use a
- variant which does not call the macro `AC_PROG_CC_WORKS'. Examples
- can be found in various `configure.in' files for libraries that are
- compiled with cross compilers, such as libiberty or libgloss.
- This is essentially a bug in autoconf, and there will probably be
- a better workaround at some point.
-
-`AC_PROG_CXX'
- If you are writing C++ code, you will want to use this macro. It
- locates the C++ compiler to use. It does not take any arguments.
- The same cross compiler comments apply as for `AC_PROG_CC'.
-
-`AM_PROG_LIBTOOL'
- If you want to build libraries, and you want to permit them to be
- shared, or you want to link against libraries which were built
- using libtool, then you will need this macro. This macro is
- required in order to use libtool.
-
- By default, this will cause all libraries to be built as shared
- libraries. To prevent this-to change the default-use
- `AM_DISABLE_SHARED' before `AM_PROG_LIBTOOL'. The configure
- options `--enable-shared' and `--disable-shared' may be used to
- override the default at build time.
-
-`AC_DEFINE(_GNU_SOURCE)'
- GNU packages should normally include this line before any other
- feature tests. This defines the macro `_GNU_SOURCE' when
- compiling, which directs the libc header files to provide the
- standard GNU system interfaces including all GNU extensions. If
- this macro is not defined, certain GNU extensions may not be
- available.
-
-`AC_OUTPUT'
- This macro takes a list of file names which the configure process
- should produce. This is normally a list of one or more `Makefile'
- files in different directories. If your package lives entirely in
- a single directory, you would use simply `AC_OUTPUT(Makefile)'.
- If you also have, for example, a `lib' subdirectory, you would use
- `AC_OUTPUT(Makefile lib/Makefile)'.
-
- If you want to use locally defined macros in your `configure.in'
-file, then you will need to write a `acinclude.m4' file which defines
-them (if not using automake, this file is called `aclocal.m4').
-Alternatively, you can put separate macros in an `m4' subdirectory, and
-put `ACLOCAL_AMFLAGS = -I m4' in your `Makefile.am' file so that the
-`aclocal' program will be able to find them.
-
- The different macro prefixes indicate which tool defines the macro.
-Macros which start with `AC_' are part of autoconf. Macros which start
-with `AM_' are provided by automake or libtool.
-
-\1f
-File: configure.info, Node: Write Makefile.am, Next: Write acconfig.h, Prev: Write configure.in, Up: Getting Started
-
-2.2 Write Makefile.am
-=====================
-
-You must write the file `Makefile.am'. This is an automake input file,
-and the automake manual describes in detail what this file should look
-like.
-
- The automake commands in `Makefile.am' mostly look like variable
-assignments in a `Makefile'. automake recognizes special variable
-names, and automatically add make rules to the output as needed.
-
- There will be one `Makefile.am' file for each directory in your
-package. For each directory with subdirectories, the `Makefile.am'
-file should contain the line
- SUBDIRS = DIR DIR ...
- where each DIR is the name of a subdirectory.
-
- For each `Makefile.am', there should be a corresponding `Makefile'
-in the `AC_OUTPUT' macro in `configure.in'.
-
- Every `Makefile.am' written at Cygnus should contain the line
- AUTOMAKE_OPTIONS = cygnus
- This puts automake into Cygnus mode. See the automake manual for
-details.
-
- You may to include the version number of `automake' that you are
-using on the `AUTOMAKE_OPTIONS' line. For example,
- AUTOMAKE_OPTIONS = cygnus 1.3
- This will prevent users from running an earlier version of
-`automake' and perhaps getting an invalid `Makefile.in'.
-
- If your package builds a program, then in the directory where that
-program is built you will normally want a line like
- bin_PROGRAMS = PROGRAM
- where PROGRAM is the name of the program. You will then want a line
-like
- PROGRAM_SOURCES = FILE FILE ...
- where each FILE is the name of a source file to link into the
-program (e.g., `foo.c').
-
- If your package builds a library, and you do not want the library to
-ever be built as a shared library, then in the directory where that
-library is built you will normally want a line like
- lib_LIBRARIES = libNAME.a
- where `libNAME.a' is the name of the library. You will then want a
-line like
- libNAME_a_SOURCES = FILE FILE ...
- where each FILE is the name of a source file to add to the library.
-
- If your package builds a library, and you want to permit building the
-library as a shared library, then in the directory where that library is
-built you will normally want a line like
- lib_LTLIBRARIES = libNAME.la
- The use of `LTLIBRARIES', and the `.la' extension, indicate a
-library to be built using libtool. As usual, you will then want a line
-like
- libNAME_la_SOURCES = FILE FILE ...
-
- The strings `bin' and `lib' that appear above in `bin_PROGRAMS' and
-`lib_LIBRARIES' are not arbitrary. They refer to particular
-directories, which may be set by the `--bindir' and `--libdir' options
-to `configure'. If those options are not used, the default values are
-based on the `--prefix' or `--exec-prefix' options to `configure'. It
-is possible to use other names if the program or library should be
-installed in some other directory.
-
- The `Makefile.am' file may also contain almost anything that may
-appear in a normal `Makefile'. automake also supports many other
-special variables, as well as conditionals.
-
- See the automake manual for more information.
-
-\1f
-File: configure.info, Node: Write acconfig.h, Next: Generate files, Prev: Write Makefile.am, Up: Getting Started
-
-2.3 Write acconfig.h
-====================
-
-If you are generating a portability header file, (i.e., you are using
-`AM_CONFIG_HEADER' in `configure.in'), then you will have to write a
-`acconfig.h' file. It will have to contain the following lines.
-
- /* Name of package. */
- #undef PACKAGE
-
- /* Version of package. */
- #undef VERSION
-
- This requirement is really a bug in the system, and the requirement
-may be eliminated at some later date.
-
- The `acconfig.h' file will also similar comment and `#undef' lines
-for any unusual macros in the `configure.in' file, including any macro
-which appears in a `AC_DEFINE' macro.
-
- In particular, if you are writing a GNU package and therefore include
-`AC_DEFINE(_GNU_SOURCE)' in `configure.in' as suggested above, you will
-need lines like this in `acconfig.h':
- /* Enable GNU extensions. */
- #undef _GNU_SOURCE
-
- Normally the `autoheader' program will inform you of any such
-requirements by printing an error message when it is run. However, if
-you do anything particular odd in your `configure.in' file, you will
-have to make sure that the right entries appear in `acconfig.h', since
-otherwise the results of the tests may not be available in the
-`config.h' file which your code will use.
-
- (Thee `PACKAGE' and `VERSION' lines are not required if you are not
-using automake, and in that case you may not need a `acconfig.h' file
-at all).
-
-\1f
-File: configure.info, Node: Generate files, Next: Getting Started Example, Prev: Write acconfig.h, Up: Getting Started
-
-2.4 Generate files
-==================
-
-Once you have written `configure.in', `Makefile.am', `acconfig.h', and
-possibly `acinclude.m4', you must use autoconf and automake programs to
-produce the first versions of the generated files. This is done by
-executing the following sequence of commands.
-
- aclocal
- autoconf
- autoheader
- automake
-
- The `aclocal' and `automake' commands are part of the automake
-package, and the `autoconf' and `autoheader' commands are part of the
-autoconf package.
-
- If you are using a `m4' subdirectory for your macros, you will need
-to use the `-I m4' option when you run `aclocal'.
-
- If you are not using the Cygnus tree, use the `-a' option when
-running `automake' command in order to copy the required support files
-into your source directory.
-
- If you are using libtool, you must build and install the libtool
-package with the same `--prefix' and `--exec-prefix' options as you
-used with the autoconf and automake packages. You must do this before
-running any of the above commands. If you are not using the Cygnus
-tree, you will need to run the `libtoolize' program to copy the libtool
-support files into your directory.
-
- Once you have managed to run these commands without getting any
-errors, you should create a new empty directory, and run the `configure'
-script which will have been created by `autoconf' with the
-`--enable-maintainer-mode' option. This will give you a set of
-Makefiles which will include rules to automatically rebuild all the
-generated files.
-
- After doing that, whenever you have changed some of the input files
-and want to regenerated the other files, go to your object directory
-and run `make'. Doing this is more reliable than trying to rebuild the
-files manually, because there are complex order dependencies and it is
-easy to forget something.
-
-\1f
-File: configure.info, Node: Getting Started Example, Prev: Generate files, Up: Getting Started
-
-2.5 Example
-===========
-
-Let's consider a trivial example.
-
- Suppose we want to write a simple version of `touch'. Our program,
-which we will call `poke', will take a single file name argument, and
-use the `utime' system call to set the modification and access times of
-the file to the current time. We want this program to be highly
-portable.
-
- We'll first see what this looks like without using autoconf and
-automake, and then see what it looks like with them.
-
-* Menu:
-
-* Getting Started Example 1:: First Try.
-* Getting Started Example 2:: Second Try.
-* Getting Started Example 3:: Third Try.
-* Generate Files in Example:: Generate Files.
-
-\1f
-File: configure.info, Node: Getting Started Example 1, Next: Getting Started Example 2, Up: Getting Started Example
-
-2.5.1 First Try
----------------
-
-Here is our first try at `poke.c'. Note that we've written it without
-ANSI/ISO C prototypes, since we want it to be highly portable.
-
- #include <stdio.h>
- #include <stdlib.h>
- #include <sys/types.h>
- #include <utime.h>
-
- int
- main (argc, argv)
- int argc;
- char **argv;
- {
- if (argc != 2)
- {
- fprintf (stderr, "Usage: poke file\n");
- exit (1);
- }
-
- if (utime (argv[1], NULL) < 0)
- {
- perror ("utime");
- exit (1);
- }
-
- exit (0);
- }
-
- We also write a simple `Makefile'.
-
- CC = gcc
- CFLAGS = -g -O2
-
- all: poke
-
- poke: poke.o
- $(CC) -o poke $(CFLAGS) $(LDFLAGS) poke.o
-
- So far, so good.
-
- Unfortunately, there are a few problems.
-
- On older Unix systems derived from BSD 4.3, the `utime' system call
-does not accept a second argument of `NULL'. On those systems, we need
-to pass a pointer to `struct utimbuf' structure. Unfortunately, even
-older systems don't define that structure; on those systems, we need to
-pass an array of two `long' values.
-
- The header file `stdlib.h' was invented by ANSI C, and older systems
-don't have a copy. We included it above to get a declaration of `exit'.
-
- We can find some of these portability problems by running
-`autoscan', which will create a `configure.scan' file which we can use
-as a prototype for our `configure.in' file. I won't show the output,
-but it will notice the potential problems with `utime' and `stdlib.h'.
-
- In our `Makefile', we don't provide any way to install the program.
-This doesn't matter much for such a simple example, but a real program
-will need an `install' target. For that matter, we will also want a
-`clean' target.
-
-\1f
-File: configure.info, Node: Getting Started Example 2, Next: Getting Started Example 3, Prev: Getting Started Example 1, Up: Getting Started Example
-
-2.5.2 Second Try
-----------------
-
-Here is our second try at this program.
-
- We modify `poke.c' to use preprocessor macros to control what
-features are available. (I've cheated a bit by using the same macro
-names which autoconf will use).
-
- #include <stdio.h>
-
- #ifdef STDC_HEADERS
- #include <stdlib.h>
- #endif
-
- #include <sys/types.h>
-
- #ifdef HAVE_UTIME_H
- #include <utime.h>
- #endif
-
- #ifndef HAVE_UTIME_NULL
-
- #include <time.h>
-
- #ifndef HAVE_STRUCT_UTIMBUF
-
- struct utimbuf
- {
- long actime;
- long modtime;
- };
-
- #endif
-
- static int
- utime_now (file)
- char *file;
- {
- struct utimbuf now;
-
- now.actime = now.modtime = time (NULL);
- return utime (file, &now);
- }
-
- #define utime(f, p) utime_now (f)
-
- #endif /* HAVE_UTIME_NULL */
-
- int
- main (argc, argv)
- int argc;
- char **argv;
- {
- if (argc != 2)
- {
- fprintf (stderr, "Usage: poke file\n");
- exit (1);
- }
-
- if (utime (argv[1], NULL) < 0)
- {
- perror ("utime");
- exit (1);
- }
-
- exit (0);
- }
-
- Here is the associated `Makefile'. We've added support for the
-preprocessor flags we use. We've also added `install' and `clean'
-targets.
-
- # Set this to your installation directory.
- bindir = /usr/local/bin
-
- # Uncomment this if you have the standard ANSI/ISO C header files.
- # STDC_HDRS = -DSTDC_HEADERS
-
- # Uncomment this if you have utime.h.
- # UTIME_H = -DHAVE_UTIME_H
-
- # Uncomment this if utime (FILE, NULL) works on your system.
- # UTIME_NULL = -DHAVE_UTIME_NULL
-
- # Uncomment this if struct utimbuf is defined in utime.h.
- # UTIMBUF = -DHAVE_STRUCT_UTIMBUF
-
- CC = gcc
- CFLAGS = -g -O2
-
- ALL_CFLAGS = $(STDC_HDRS) $(UTIME_H) $(UTIME_NULL) $(UTIMBUF) $(CFLAGS)
-
- all: poke
-
- poke: poke.o
- $(CC) -o poke $(ALL_CFLAGS) $(LDFLAGS) poke.o
-
- .c.o:
- $(CC) -c $(ALL_CFLAGS) poke.c
-
- install: poke
- cp poke $(bindir)/poke
-
- clean:
- rm poke poke.o
-
- Some problems with this approach should be clear.
-
- Users who want to compile poke will have to know how `utime' works
-on their systems, so that they can uncomment the `Makefile' correctly.
-
- The installation is done using `cp', but many systems have an
-`install' program which may be used, and which supports optional
-features such as stripping debugging information out of the installed
-binary.
-
- The use of `Makefile' variables like `CC', `CFLAGS' and `LDFLAGS'
-follows the requirements of the GNU standards. This is convenient for
-all packages, since it reduces surprises for users. However, it is
-easy to get the details wrong, and wind up with a slightly nonstandard
-distribution.
-
-\1f
-File: configure.info, Node: Getting Started Example 3, Next: Generate Files in Example, Prev: Getting Started Example 2, Up: Getting Started Example
-
-2.5.3 Third Try
----------------
-
-For our third try at this program, we will write a `configure.in'
-script to discover the configuration features on the host system, rather
-than requiring the user to edit the `Makefile'. We will also write a
-`Makefile.am' rather than a `Makefile'.
-
- The only change to `poke.c' is to add a line at the start of the
-file:
- #include "config.h"
-
- The new `configure.in' file is as follows.
-
- AC_INIT(poke.c)
- AM_INIT_AUTOMAKE(poke, 1.0)
- AM_CONFIG_HEADER(config.h:config.in)
- AC_PROG_CC
- AC_HEADER_STDC
- AC_CHECK_HEADERS(utime.h)
- AC_EGREP_HEADER(utimbuf, utime.h, AC_DEFINE(HAVE_STRUCT_UTIMBUF))
- AC_FUNC_UTIME_NULL
- AC_OUTPUT(Makefile)
-
- The first four macros in this file, and the last one, were described
-above; see *Note Write configure.in::. If we omit these macros, then
-when we run `automake' we will get a reminder that we need them.
-
- The other macros are standard autoconf macros.
-
-`AC_HEADER_STDC'
- Check for standard C headers.
-
-`AC_CHECK_HEADERS'
- Check whether a particular header file exists.
-
-`AC_EGREP_HEADER'
- Check for a particular string in a particular header file, in this
- case checking for `utimbuf' in `utime.h'.
-
-`AC_FUNC_UTIME_NULL'
- Check whether `utime' accepts a NULL second argument to set the
- file change time to the current time.
-
- See the autoconf manual for a more complete description.
-
- The new `Makefile.am' file is as follows. Note how simple this is
-compared to our earlier `Makefile'.
-
- bin_PROGRAMS = poke
-
- poke_SOURCES = poke.c
-
- This means that we should build a single program name `poke'. It
-should be installed in the binary directory, which we called `bindir'
-earlier. The program `poke' is built from the source file `poke.c'.
-
- We must also write a `acconfig.h' file. Besides `PACKAGE' and
-`VERSION', which must be mentioned for all packages which use automake,
-we must include `HAVE_STRUCT_UTIMBUF', since we mentioned it in an
-`AC_DEFINE'.
-
- /* Name of package. */
- #undef PACKAGE
-
- /* Version of package. */
- #undef VERSION
-
- /* Whether utime.h defines struct utimbuf. */
- #undef HAVE_STRUCT_UTIMBUF
-
-\1f
-File: configure.info, Node: Generate Files in Example, Prev: Getting Started Example 3, Up: Getting Started Example
-
-2.5.4 Generate Files
---------------------
-
-We must now generate the other files, using the following commands.
-
- aclocal
- autoconf
- autoheader
- automake
-
- When we run `autoheader', it will remind us of any macros we forgot
-to add to `acconfig.h'.
-
- When we run `automake', it will want to add some files to our
-distribution. It will add them automatically if we use the
-`--add-missing' option.
-
- By default, `automake' will run in GNU mode, which means that it
-will want us to create certain additional files; as of this writing, it
-will want `NEWS', `README', `AUTHORS', and `ChangeLog', all of which
-are files which should appear in a standard GNU distribution. We can
-either add those files, or run `automake' with the `--foreign' option.
-
- Running these tools will generate the following files, all of which
-are described in the next chapter.
-
- * `aclocal.m4'
-
- * `configure'
-
- * `config.in'
-
- * `Makefile.in'
-
- * `stamp-h.in'
-
-\1f
-File: configure.info, Node: Files, Next: Configuration Names, Prev: Getting Started, Up: Top
-
-3 Files
-*******
-
-As was seen in the previous chapter, the GNU configure and build system
-uses a number of different files. The developer must write a few files.
-The others are generated by various tools.
-
- The system is rather flexible, and can be used in many different
-ways. In describing the files that it uses, I will describe the common
-case, and mention some other cases that may arise.
-
-* Menu:
-
-* Developer Files:: Developer Files.
-* Build Files:: Build Files.
-* Support Files:: Support Files.
-
-\1f
-File: configure.info, Node: Developer Files, Next: Build Files, Up: Files
-
-3.1 Developer Files
-===================
-
-This section describes the files written or generated by the developer
-of a package.
-
-* Menu:
-
-* Developer Files Picture:: Developer Files Picture.
-* Written Developer Files:: Written Developer Files.
-* Generated Developer Files:: Generated Developer Files.
-
-\1f
-File: configure.info, Node: Developer Files Picture, Next: Written Developer Files, Up: Developer Files
-
-3.1.1 Developer Files Picture
------------------------------
-
-Here is a picture of the files which are written by the developer, the
-generated files which would be included with a complete source
-distribution, and the tools which create those files. The file names
-are plain text and the tool names are enclosed by `*' characters (e.g.,
-`autoheader' is the name of a tool, not the name of a file).
-
- acconfig.h configure.in Makefile.am
- | | |
- | --------------+---------------------- |
- | | | | |
- v v | acinclude.m4 | |
- *autoheader* | | v v
- | | v --->*automake*
- v |--->*aclocal* | |
- config.in | | | v
- | v | Makefile.in
- | aclocal.m4---
- | |
- v v
- *autoconf*
- |
- v
- configure
-
-\1f
-File: configure.info, Node: Written Developer Files, Next: Generated Developer Files, Prev: Developer Files Picture, Up: Developer Files
-
-3.1.2 Written Developer Files
------------------------------
-
-The following files would be written by the developer.
-
-`configure.in'
- This is the configuration script. This script contains
- invocations of autoconf macros. It may also contain ordinary
- shell script code. This file will contain feature tests for
- portability issues. The last thing in the file will normally be
- an `AC_OUTPUT' macro listing which files to create when the
- builder runs the configure script. This file is always required
- when using the GNU configure system. *Note Write configure.in::.
-
-`Makefile.am'
- This is the automake input file. It describes how the code should
- be built. It consists of definitions of automake variables. It
- may also contain ordinary Makefile targets. This file is only
- needed when using automake (newer tools normally use automake, but
- there are still older tools which have not been converted, in
- which the developer writes `Makefile.in' directly). *Note Write
- Makefile.am::.
-
-`acconfig.h'
- When the configure script creates a portability header file, by
- using `AM_CONFIG_HEADER' (or, if not using automake,
- `AC_CONFIG_HEADER'), this file is used to describe macros which are
- not recognized by the `autoheader' command. This is normally a
- fairly uninteresting file, consisting of a collection of `#undef'
- lines with comments. Normally any call to `AC_DEFINE' in
- `configure.in' will require a line in this file. *Note Write
- acconfig.h::.
-
-`acinclude.m4'
- This file is not always required. It defines local autoconf
- macros. These macros may then be used in `configure.in'. If you
- don't need any local autoconf macros, then you don't need this
- file at all. In fact, in general, you never need local autoconf
- macros, since you can put everything in `configure.in', but
- sometimes a local macro is convenient.
-
- Newer tools may omit `acinclude.m4', and instead use a
- subdirectory, typically named `m4', and define `ACLOCAL_AMFLAGS =
- -I m4' in `Makefile.am' to force `aclocal' to look there for macro
- definitions. The macro definitions are then placed in separate
- files in that directory.
-
- The `acinclude.m4' file is only used when using automake; in older
- tools, the developer writes `aclocal.m4' directly, if it is needed.
-
-\1f
-File: configure.info, Node: Generated Developer Files, Prev: Written Developer Files, Up: Developer Files
-
-3.1.3 Generated Developer Files
--------------------------------
-
-The following files would be generated by the developer.
-
- When using automake, these files are normally not generated manually
-after the first time. Instead, the generated `Makefile' contains rules
-to automatically rebuild the files as required. When
-`AM_MAINTAINER_MODE' is used in `configure.in' (the normal case in
-Cygnus code), the automatic rebuilding rules will only be defined if
-you configure using the `--enable-maintainer-mode' option.
-
- When using automatic rebuilding, it is important to ensure that all
-the various tools have been built and installed on your `PATH'. Using
-automatic rebuilding is highly recommended, so much so that I'm not
-going to explain what you have to do if you don't use it.
-
-`configure'
- This is the configure script which will be run when building the
- package. This is generated by `autoconf' from `configure.in' and
- `aclocal.m4'. This is a shell script.
-
-`Makefile.in'
- This is the file which the configure script will turn into the
- `Makefile' at build time. This file is generated by `automake'
- from `Makefile.am'. If you aren't using automake, you must write
- this file yourself. This file is pretty much a normal `Makefile',
- with some configure substitutions for certain variables.
-
-`aclocal.m4'
- This file is created by the `aclocal' program, based on the
- contents of `configure.in' and `acinclude.m4' (or, as noted in the
- description of `acinclude.m4' above, on the contents of an `m4'
- subdirectory). This file contains definitions of autoconf macros
- which `autoconf' will use when generating the file `configure'.
- These autoconf macros may be defined by you in `acinclude.m4' or
- they may be defined by other packages such as automake, libtool or
- gettext. If you aren't using automake, you will normally write
- this file yourself; in that case, if `configure.in' uses only
- standard autoconf macros, this file will not be needed at all.
-
-`config.in'
- This file is created by `autoheader' based on `acconfig.h' and
- `configure.in'. At build time, the configure script will define
- some of the macros in it to create `config.h', which may then be
- included by your program. This permits your C code to use
- preprocessor conditionals to change its behaviour based on the
- characteristics of the host system. This file may also be called
- `config.h.in'.
-
-`stamp.h-in'
- This rather uninteresting file, which I omitted from the picture,
- is generated by `automake'. It always contains the string
- `timestamp'. It is used as a timestamp file indicating whether
- `config.in' is up to date. Using a timestamp file means that
- `config.in' can be marked as up to date without actually changing
- its modification time. This is useful since `config.in' depends
- upon `configure.in', but it is easy to change `configure.in' in a
- way which does not affect `config.in'.
-
-\1f
-File: configure.info, Node: Build Files, Next: Support Files, Prev: Developer Files, Up: Files
-
-3.2 Build Files
-===============
-
-This section describes the files which are created at configure and
-build time. These are the files which somebody who builds the package
-will see.
-
- Of course, the developer will also build the package. The
-distinction between developer files and build files is not that the
-developer does not see the build files, but that somebody who only
-builds the package does not have to worry about the developer files.
-
-* Menu:
-
-* Build Files Picture:: Build Files Picture.
-* Build Files Description:: Build Files Description.
-
-\1f
-File: configure.info, Node: Build Files Picture, Next: Build Files Description, Up: Build Files
-
-3.2.1 Build Files Picture
--------------------------
-
-Here is a picture of the files which will be created at build time.
-`config.status' is both a created file and a shell script which is run
-to create other files, and the picture attempts to show that.
-
- config.in *configure* Makefile.in
- | | |
- | v |
- | config.status |
- | | |
- *config.status*<======+==========>*config.status*
- | |
- v v
- config.h Makefile
-
-\1f
-File: configure.info, Node: Build Files Description, Prev: Build Files Picture, Up: Build Files
-
-3.2.2 Build Files Description
------------------------------
-
-This is a description of the files which are created at build time.
-
-`config.status'
- The first step in building a package is to run the `configure'
- script. The `configure' script will create the file
- `config.status', which is itself a shell script. When you first
- run `configure', it will automatically run `config.status'. An
- `Makefile' derived from an automake generated `Makefile.in' will
- contain rules to automatically run `config.status' again when
- necessary to recreate certain files if their inputs change.
-
-`Makefile'
- This is the file which make will read to build the program. The
- `config.status' script will transform `Makefile.in' into
- `Makefile'.
-
-`config.h'
- This file defines C preprocessor macros which C code can use to
- adjust its behaviour on different systems. The `config.status'
- script will transform `config.in' into `config.h'.
-
-`config.cache'
- This file did not fit neatly into the picture, and I omitted it.
- It is used by the `configure' script to cache results between
- runs. This can be an important speedup. If you modify
- `configure.in' in such a way that the results of old tests should
- change (perhaps you have added a new library to `LDFLAGS'), then
- you will have to remove `config.cache' to force the tests to be
- rerun.
-
- The autoconf manual explains how to set up a site specific cache
- file. This can speed up running `configure' scripts on your
- system.
-
-`stamp.h'
- This file, which I omitted from the picture, is similar to
- `stamp-h.in'. It is used as a timestamp file indicating whether
- `config.h' is up to date. This is useful since `config.h' depends
- upon `config.status', but it is easy for `config.status' to change
- in a way which does not affect `config.h'.
-
-\1f
-File: configure.info, Node: Support Files, Prev: Build Files, Up: Files
-
-3.3 Support Files
-=================
-
-The GNU configure and build system requires several support files to be
-included with your distribution. You do not normally need to concern
-yourself with these. If you are using the Cygnus tree, most are already
-present. Otherwise, they will be installed with your source by
-`automake' (with the `--add-missing' option) and `libtoolize'.
-
- You don't have to put the support files in the top level directory.
-You can put them in a subdirectory, and use the `AC_CONFIG_AUX_DIR'
-macro in `configure.in' to tell `automake' and the `configure' script
-where they are.
-
- In this section, I describe the support files, so that you can know
-what they are and why they are there.
-
-`ABOUT-NLS'
- Added by automake if you are using gettext. This is a
- documentation file about the gettext project.
-
-`ansi2knr.c'
- Used by an automake generated `Makefile' if you put `ansi2knr' in
- `AUTOMAKE_OPTIONS' in `Makefile.am'. This permits compiling ANSI
- C code with a K&R C compiler.
-
-`ansi2knr.1'
- The man page which goes with `ansi2knr.c'.
-
-`config.guess'
- A shell script which determines the configuration name for the
- system on which it is run.
-
-`config.sub'
- A shell script which canonicalizes a configuration name entered by
- a user.
-
-`elisp-comp'
- Used to compile Emacs LISP files.
-
-`install-sh'
- A shell script which installs a program. This is used if the
- configure script can not find an install binary.
-
-`ltconfig'
- Used by libtool. This is a shell script which configures libtool
- for the particular system on which it is used.
-
-`ltmain.sh'
- Used by libtool. This is the actual libtool script which is used,
- after it is configured by `ltconfig' to build a library.
-
-`mdate-sh'
- A shell script used by an automake generated `Makefile' to pretty
- print the modification time of a file. This is used to maintain
- version numbers for texinfo files.
-
-`missing'
- A shell script used if some tool is missing entirely. This is
- used by an automake generated `Makefile' to avoid certain sorts of
- timestamp problems.
-
-`mkinstalldirs'
- A shell script which creates a directory, including all parent
- directories. This is used by an automake generated `Makefile'
- during installation.
-
-`texinfo.tex'
- Required if you have any texinfo files. This is used when
- converting Texinfo files into DVI using `texi2dvi' and TeX.
-
-`ylwrap'
- A shell script used by an automake generated `Makefile' to run
- programs like `bison', `yacc', `flex', and `lex'. These programs
- default to producing output files with a fixed name, and the
- `ylwrap' script runs them in a subdirectory to avoid file name
- conflicts when using a parallel make program.
-
-\1f
-File: configure.info, Node: Configuration Names, Next: Cross Compilation Tools, Prev: Files, Up: Top
-
-4 Configuration Names
-*********************
-
-The GNU configure system names all systems using a "configuration
-name". All such names used to be triplets (they may now contain four
-parts in certain cases), and the term "configuration triplet" is still
-seen.
-
-* Menu:
-
-* Configuration Name Definition:: Configuration Name Definition.
-* Using Configuration Names:: Using Configuration Names.
-
-\1f
-File: configure.info, Node: Configuration Name Definition, Next: Using Configuration Names, Up: Configuration Names
-
-4.1 Configuration Name Definition
-=================================
-
-This is a string of the form CPU-MANUFACTURER-OPERATING_SYSTEM. In
-some cases, this is extended to a four part form:
-CPU-MANUFACTURER-KERNEL-OPERATING_SYSTEM.
-
- When using a configuration name in a configure option, it is normally
-not necessary to specify an entire name. In particular, the
-MANUFACTURER field is often omitted, leading to strings such as
-`i386-linux' or `sparc-sunos'. The shell script `config.sub' will
-translate these shortened strings into the canonical form. autoconf
-will arrange for `config.sub' to be run automatically when it is needed.
-
- The fields of a configuration name are as follows:
-
-CPU
- The type of processor. This is typically something like `i386' or
- `sparc'. More specific variants are used as well, such as
- `mipsel' to indicate a little endian MIPS processor.
-
-MANUFACTURER
- A somewhat freeform field which indicates the manufacturer of the
- system. This is often simply `unknown'. Other common strings are
- `pc' for an IBM PC compatible system, or the name of a workstation
- vendor, such as `sun'.
-
-OPERATING_SYSTEM
- The name of the operating system which is run on the system. This
- will be something like `solaris2.5' or `irix6.3'. There is no
- particular restriction on the version number, and strings like
- `aix4.1.4.0' are seen. For an embedded system, which has no
- operating system, this field normally indicates the type of object
- file format, such as `elf' or `coff'.
-
-KERNEL
- This is used mainly for GNU/Linux. A typical GNU/Linux
- configuration name is `i586-pc-linux-gnulibc1'. In this case the
- kernel, `linux', is separated from the operating system,
- `gnulibc1'.
-
- The shell script `config.guess' will normally print the correct
-configuration name for the system on which it is run. It does by
-running `uname' and by examining other characteristics of the system.
-
- Because `config.guess' can normally determine the configuration name
-for a machine, it is normally only necessary to specify a configuration
-name when building a cross-compiler or when building using a
-cross-compiler.
-
-\1f
-File: configure.info, Node: Using Configuration Names, Prev: Configuration Name Definition, Up: Configuration Names
-
-4.2 Using Configuration Names
-=============================
-
-A configure script will sometimes have to make a decision based on a
-configuration name. You will need to do this if you have to compile
-code differently based on something which can not be tested using a
-standard autoconf feature test.
-
- It is normally better to test for particular features, rather than to
-test for a particular system. This is because as Unix evolves,
-different systems copy features from one another. Even if you need to
-determine whether the feature is supported based on a configuration
-name, you should define a macro which describes the feature, rather than
-defining a macro which describes the particular system you are on.
-
- Testing for a particular system is normally done using a case
-statement in `configure.in'. The case statement might look something
-like the following, assuming that `host' is a shell variable holding a
-canonical configuration name (which will be the case if `configure.in'
-uses the `AC_CANONICAL_HOST' or `AC_CANONICAL_SYSTEM' macro).
-
- case "${host}" in
- i[3-7]86-*-linux-gnu*) do something ;;
- sparc*-sun-solaris2.[56789]*) do something ;;
- sparc*-sun-solaris*) do something ;;
- mips*-*-elf*) do something ;;
- esac
-
- It is particularly important to use `*' after the operating system
-field, in order to match the version number which will be generated by
-`config.guess'.
-
- In most cases you must be careful to match a range of processor
-types. For most processor families, a trailing `*' suffices, as in
-`mips*' above. For the i386 family, something along the lines of
-`i[3-7]86' suffices at present. For the m68k family, you will need
-something like `m68*'. Of course, if you do not need to match on the
-processor, it is simpler to just replace the entire field by a `*', as
-in `*-*-irix*'.
-
-\1f
-File: configure.info, Node: Cross Compilation Tools, Next: Canadian Cross, Prev: Configuration Names, Up: Top
-
-5 Cross Compilation Tools
-*************************
-
-The GNU configure and build system can be used to build "cross
-compilation" tools. A cross compilation tool is a tool which runs on
-one system and produces code which runs on another system.
-
-* Menu:
-
-* Cross Compilation Concepts:: Cross Compilation Concepts.
-* Host and Target:: Host and Target.
-* Using the Host Type:: Using the Host Type.
-* Specifying the Target:: Specifying the Target.
-* Using the Target Type:: Using the Target Type.
-* Cross Tools in the Cygnus Tree:: Cross Tools in the Cygnus Tree
-
-\1f
-File: configure.info, Node: Cross Compilation Concepts, Next: Host and Target, Up: Cross Compilation Tools
-
-5.1 Cross Compilation Concepts
-==============================
-
-A compiler which produces programs which run on a different system is a
-cross compilation compiler, or simply a "cross compiler". Similarly,
-we speak of cross assemblers, cross linkers, etc.
-
- In the normal case, a compiler produces code which runs on the same
-system as the one on which the compiler runs. When it is necessary to
-distinguish this case from the cross compilation case, such a compiler
-is called a "native compiler". Similarly, we speak of native
-assemblers, etc.
-
- Although the debugger is not strictly speaking a compilation tool,
-it is nevertheless meaningful to speak of a cross debugger: a debugger
-which is used to debug code which runs on another system. Everything
-that is said below about configuring cross compilation tools applies to
-the debugger as well.
-
-\1f
-File: configure.info, Node: Host and Target, Next: Using the Host Type, Prev: Cross Compilation Concepts, Up: Cross Compilation Tools
-
-5.2 Host and Target
-===================
-
-When building cross compilation tools, there are two different systems
-involved: the system on which the tools will run, and the system for
-which the tools generate code.
-
- The system on which the tools will run is called the "host" system.
-
- The system for which the tools generate code is called the "target"
-system.
-
- For example, suppose you have a compiler which runs on a GNU/Linux
-system and generates ELF programs for a MIPS embedded system. In this
-case the GNU/Linux system is the host, and the MIPS ELF system is the
-target. Such a compiler could be called a GNU/Linux cross MIPS ELF
-compiler, or, equivalently, a `i386-linux-gnu' cross `mips-elf'
-compiler.
-
- Naturally, most programs are not cross compilation tools. For those
-programs, it does not make sense to speak of a target. It only makes
-sense to speak of a target for tools like `gcc' or the `binutils' which
-actually produce running code. For example, it does not make sense to
-speak of the target of a tool like `bison' or `make'.
-
- Most cross compilation tools can also serve as native tools. For a
-native compilation tool, it is still meaningful to speak of a target.
-For a native tool, the target is the same as the host. For example, for
-a GNU/Linux native compiler, the host is GNU/Linux, and the target is
-also GNU/Linux.
-
-\1f
-File: configure.info, Node: Using the Host Type, Next: Specifying the Target, Prev: Host and Target, Up: Cross Compilation Tools
-
-5.3 Using the Host Type
-=======================
-
-In almost all cases the host system is the system on which you run the
-`configure' script, and on which you build the tools (for the case when
-they differ, *note Canadian Cross::).
-
- If your configure script needs to know the configuration name of the
-host system, and the package is not a cross compilation tool and
-therefore does not have a target, put `AC_CANONICAL_HOST' in
-`configure.in'. This macro will arrange to define a few shell
-variables when the `configure' script is run.
-
-`host'
- The canonical configuration name of the host. This will normally
- be determined by running the `config.guess' shell script, although
- the user is permitted to override this by using an explicit
- `--host' option.
-
-`host_alias'
- In the unusual case that the user used an explicit `--host' option,
- this will be the argument to `--host'. In the normal case, this
- will be the same as the `host' variable.
-
-`host_cpu'
-`host_vendor'
-`host_os'
- The first three parts of the canonical configuration name.
-
- The shell variables may be used by putting shell code in
-`configure.in'. For an example, see *Note Using Configuration Names::.
-
-\1f
-File: configure.info, Node: Specifying the Target, Next: Using the Target Type, Prev: Using the Host Type, Up: Cross Compilation Tools
-
-5.4 Specifying the Target
-=========================
-
-By default, the `configure' script will assume that the target is the
-same as the host. This is the more common case; for example, it leads
-to a native compiler rather than a cross compiler.
-
- If you want to build a cross compilation tool, you must specify the
-target explicitly by using the `--target' option when you run
-`configure'. The argument to `--target' is the configuration name of
-the system for which you wish to generate code. *Note Configuration
-Names::.
-
- For example, to build tools which generate code for a MIPS ELF
-embedded system, you would use `--target mips-elf'.
-
-\1f
-File: configure.info, Node: Using the Target Type, Next: Cross Tools in the Cygnus Tree, Prev: Specifying the Target, Up: Cross Compilation Tools
-
-5.5 Using the Target Type
-=========================
-
-When writing `configure.in' for a cross compilation tool, you will need
-to use information about the target. To do this, put
-`AC_CANONICAL_SYSTEM' in `configure.in'.
-
- `AC_CANONICAL_SYSTEM' will look for a `--target' option and
-canonicalize it using the `config.sub' shell script. It will also run
-`AC_CANONICAL_HOST' (*note Using the Host Type::).
-
- The target type will be recorded in the following shell variables.
-Note that the host versions of these variables will also be defined by
-`AC_CANONICAL_HOST'.
-
-`target'
- The canonical configuration name of the target.
-
-`target_alias'
- The argument to the `--target' option. If the user did not specify
- a `--target' option, this will be the same as `host_alias'.
-
-`target_cpu'
-`target_vendor'
-`target_os'
- The first three parts of the canonical target configuration name.
-
- Note that if `host' and `target' are the same string, you can assume
-a native configuration. If they are different, you can assume a cross
-configuration.
-
- It is arguably possible for `host' and `target' to represent the
-same system, but for the strings to not be identical. For example, if
-`config.guess' returns `sparc-sun-sunos4.1.4', and somebody configures
-with `--target sparc-sun-sunos4.1', then the slight differences between
-the two versions of SunOS may be unimportant for your tool. However,
-in the general case it can be quite difficult to determine whether the
-differences between two configuration names are significant or not.
-Therefore, by convention, if the user specifies a `--target' option
-without specifying a `--host' option, it is assumed that the user wants
-to configure a cross compilation tool.
-
- The variables `target' and `target_alias' should be handled
-differently.
-
- In general, whenever the user may actually see a string,
-`target_alias' should be used. This includes anything which may appear
-in the file system, such as a directory name or part of a tool name.
-It also includes any tool output, unless it is clearly labelled as the
-canonical target configuration name. This permits the user to use the
-`--target' option to specify how the tool will appear to the outside
-world.
-
- On the other hand, when checking for characteristics of the target
-system, `target' should be used. This is because a wide variety of
-`--target' options may map into the same canonical configuration name.
-You should not attempt to duplicate the canonicalization done by
-`config.sub' in your own code.
-
- By convention, cross tools are installed with a prefix of the
-argument used with the `--target' option, also known as `target_alias'
-(*note Using the Target Type::). If the user does not use the
-`--target' option, and thus is building a native tool, no prefix is
-used.
-
- For example, if gcc is configured with `--target mips-elf', then the
-installed binary will be named `mips-elf-gcc'. If gcc is configured
-without a `--target' option, then the installed binary will be named
-`gcc'.
-
- The autoconf macro `AC_ARG_PROGRAM' will handle this for you. If
-you are using automake, no more need be done; the programs will
-automatically be installed with the correct prefixes. Otherwise, see
-the autoconf documentation for `AC_ARG_PROGRAM'.
-
-\1f
-File: configure.info, Node: Cross Tools in the Cygnus Tree, Prev: Using the Target Type, Up: Cross Compilation Tools
-
-5.6 Cross Tools in the Cygnus Tree
-==================================
-
-The Cygnus tree is used for various packages including gdb, the GNU
-binutils, and egcs. It is also, of course, used for Cygnus releases.
-
- In the Cygnus tree, the top level `configure' script uses the old
-Cygnus configure system, not autoconf. The top level `Makefile.in' is
-written to build packages based on what is in the source tree, and
-supports building a large number of tools in a single
-`configure'/`make' step.
-
- The Cygnus tree may be configured with a `--target' option. The
-`--target' option applies recursively to every subdirectory, and
-permits building an entire set of cross tools at once.
-
-* Menu:
-
-* Host and Target Libraries:: Host and Target Libraries.
-* Target Library Configure Scripts:: Target Library Configure Scripts.
-* Make Targets in Cygnus Tree:: Make Targets in Cygnus Tree.
-* Target libiberty:: Target libiberty
-
-\1f
-File: configure.info, Node: Host and Target Libraries, Next: Target Library Configure Scripts, Up: Cross Tools in the Cygnus Tree
-
-5.6.1 Host and Target Libraries
--------------------------------
-
-The Cygnus tree distinguishes host libraries from target libraries.
-
- Host libraries are built with the compiler used to build the programs
-which run on the host, which is called the host compiler. This includes
-libraries such as `bfd' and `tcl'. These libraries are built with the
-host compiler, and are linked into programs like the binutils or gcc
-which run on the host.
-
- Target libraries are built with the target compiler. If gcc is
-present in the source tree, then the target compiler is the gcc that is
-built using the host compiler. Target libraries are libraries such as
-`newlib' and `libstdc++'. These libraries are not linked into the host
-programs, but are instead made available for use with programs built
-with the target compiler.
-
- For the rest of this section, assume that gcc is present in the
-source tree, so that it will be used to build the target libraries.
-
- There is a complication here. The configure process needs to know
-which compiler you are going to use to build a tool; otherwise, the
-feature tests will not work correctly. The Cygnus tree handles this by
-not configuring the target libraries until the target compiler is
-built. In order to permit everything to build using a single
-`configure'/`make', the configuration of the target libraries is
-actually triggered during the make step.
-
- When the target libraries are configured, the `--target' option is
-not used. Instead, the `--host' option is used with the argument of
-the `--target' option for the overall configuration. If no `--target'
-option was used for the overall configuration, the `--host' option will
-be passed with the output of the `config.guess' shell script. Any
-`--build' option is passed down unchanged.
-
- This translation of configuration options is done because since the
-target libraries are compiled with the target compiler, they are being
-built in order to run on the target of the overall configuration. By
-the definition of host, this means that their host system is the same as
-the target system of the overall configuration.
-
- The same process is used for both a native configuration and a cross
-configuration. Even when using a native configuration, the target
-libraries will be configured and built using the newly built compiler.
-This is particularly important for the C++ libraries, since there is no
-reason to assume that the C++ compiler used to build the host tools (if
-there even is one) uses the same ABI as the g++ compiler which will be
-used to build the target libraries.
-
- There is one difference between a native configuration and a cross
-configuration. In a native configuration, the target libraries are
-normally configured and built as siblings of the host tools. In a cross
-configuration, the target libraries are normally built in a subdirectory
-whose name is the argument to `--target'. This is mainly for
-historical reasons.
-
- To summarize, running `configure' in the Cygnus tree configures all
-the host libraries and tools, but does not configure any of the target
-libraries. Running `make' then does the following steps:
-
- * Build the host libraries.
-
- * Build the host programs, including gcc. Note that we call gcc
- both a host program (since it runs on the host) and a target
- compiler (since it generates code for the target).
-
- * Using the newly built target compiler, configure the target
- libraries.
-
- * Build the target libraries.
-
- The steps need not be done in precisely this order, since they are
-actually controlled by `Makefile' targets.
-
-\1f
-File: configure.info, Node: Target Library Configure Scripts, Next: Make Targets in Cygnus Tree, Prev: Host and Target Libraries, Up: Cross Tools in the Cygnus Tree
-
-5.6.2 Target Library Configure Scripts
---------------------------------------
-
-There are a few things you must know in order to write a configure
-script for a target library. This is just a quick sketch, and beginners
-shouldn't worry if they don't follow everything here.
-
- The target libraries are configured and built using a newly built
-target compiler. There may not be any startup files or libraries for
-this target compiler. In fact, those files will probably be built as
-part of some target library, which naturally means that they will not
-exist when your target library is configured.
-
- This means that the configure script for a target library may not use
-any test which requires doing a link. This unfortunately includes many
-useful autoconf macros, such as `AC_CHECK_FUNCS'. autoconf macros
-which do a compile but not a link, such as `AC_CHECK_HEADERS', may be
-used.
-
- This is a severe restriction, but normally not a fatal one, as target
-libraries can often assume the presence of other target libraries, and
-thus know which functions will be available.
-
- As of this writing, the autoconf macro `AC_PROG_CC' does a link to
-make sure that the compiler works. This may fail in a target library,
-so target libraries must use a different set of macros to locate the
-compiler. See the `configure.in' file in a directory like `libiberty'
-or `libgloss' for an example.
-
- As noted in the previous section, target libraries are sometimes
-built in directories which are siblings to the host tools, and are
-sometimes built in a subdirectory. The `--with-target-subdir' configure
-option will be passed when the library is configured. Its value will be
-an empty string if the target library is a sibling. Its value will be
-the name of the subdirectory if the target library is in a subdirectory.
-
- If the overall build is not a native build (i.e., the overall
-configure used the `--target' option), then the library will be
-configured with the `--with-cross-host' option. The value of this
-option will be the host system of the overall build. Recall that the
-host system of the library will be the target of the overall build. If
-the overall build is a native build, the `--with-cross-host' option
-will not be used.
-
- A library which can be built both standalone and as a target library
-may want to install itself into different directories depending upon the
-case. When built standalone, or when built native, the library should
-be installed in `$(libdir)'. When built as a target library which is
-not native, the library should be installed in `$(tooldir)/lib'. The
-`--with-cross-host' option may be used to distinguish these cases.
-
- This same test of `--with-cross-host' may be used to see whether it
-is OK to use link tests in the configure script. If the
-`--with-cross-host' option is not used, then the library is being built
-either standalone or native, and a link should work.
-
-\1f
-File: configure.info, Node: Make Targets in Cygnus Tree, Next: Target libiberty, Prev: Target Library Configure Scripts, Up: Cross Tools in the Cygnus Tree
-
-5.6.3 Make Targets in Cygnus Tree
----------------------------------
-
-The top level `Makefile' in the Cygnus tree defines targets for every
-known subdirectory.
-
- For every subdirectory DIR which holds a host library or program,
-the `Makefile' target `all-DIR' will build that library or program.
-
- There are dependencies among host tools. For example, building gcc
-requires first building gas, because the gcc build process invokes the
-target assembler. These dependencies are reflected in the top level
-`Makefile'.
-
- For every subdirectory DIR which holds a target library, the
-`Makefile' target `configure-target-DIR' will configure that library.
-The `Makefile' target `all-target-DIR' will build that library.
-
- Every `configure-target-DIR' target depends upon `all-gcc', since
-gcc, the target compiler, is required to configure the tool. Every
-`all-target-DIR' target depends upon the corresponding
-`configure-target-DIR' target.
-
- There are several other targets which may be of interest for each
-directory: `install-DIR', `clean-DIR', and `check-DIR'. There are also
-corresponding `target' versions of these for the target libraries ,
-such as `install-target-DIR'.
-
-\1f
-File: configure.info, Node: Target libiberty, Prev: Make Targets in Cygnus Tree, Up: Cross Tools in the Cygnus Tree
-
-5.6.4 Target libiberty
-----------------------
-
-The `libiberty' subdirectory is currently a special case, in that it is
-the only directory which is built both using the host compiler and
-using the target compiler.
-
- This is because the files in `libiberty' are used when building the
-host tools, and they are also incorporated into the `libstdc++' target
-library as support code.
-
- This duality does not pose any particular difficulties. It means
-that there are targets for both `all-libiberty' and
-`all-target-libiberty'.
-
- In a native configuration, when target libraries are not built in a
-subdirectory, the same objects are normally used as both the host build
-and the target build. This is normally OK, since libiberty contains
-only C code, and in a native configuration the results of the host
-compiler and the target compiler are normally interoperable.
-
- Irix 6 is again an exception here, since the SGI native compiler
-defaults to using the `O32' ABI, and gcc defaults to using the `N32'
-ABI. On Irix 6, the target libraries are built in a subdirectory even
-for a native configuration, avoiding this problem.
-
- There are currently no other libraries built for both the host and
-the target, but there is no conceptual problem with adding more.
-
-\1f
-File: configure.info, Node: Canadian Cross, Next: Cygnus Configure, Prev: Cross Compilation Tools, Up: Top
-
-6 Canadian Cross
-****************
-
-It is possible to use the GNU configure and build system to build a
-program which will run on a system which is different from the system on
-which the tools are built. In other words, it is possible to build
-programs using a cross compiler.
-
- This is referred to as a "Canadian Cross".
-
-* Menu:
-
-* Canadian Cross Example:: Canadian Cross Example.
-* Canadian Cross Concepts:: Canadian Cross Concepts.
-* Build Cross Host Tools:: Build Cross Host Tools.
-* Build and Host Options:: Build and Host Options.
-* CCross not in Cygnus Tree:: Canadian Cross not in Cygnus Tree.
-* CCross in Cygnus Tree:: Canadian Cross in Cygnus Tree.
-* Supporting Canadian Cross:: Supporting Canadian Cross.
-
-\1f
-File: configure.info, Node: Canadian Cross Example, Next: Canadian Cross Concepts, Up: Canadian Cross
-
-6.1 Canadian Cross Example
-==========================
-
-Here is an example of a Canadian Cross.
-
- While running on a GNU/Linux, you can build a program which will run
-on a Solaris system. You would use a GNU/Linux cross Solaris compiler
-to build the program.
-
- Of course, you could not run the resulting program on your GNU/Linux
-system. You would have to copy it over to a Solaris system before you
-would run it.
-
- Of course, you could also simply build the programs on the Solaris
-system in the first place. However, perhaps the Solaris system is not
-available for some reason; perhaps you actually don't have one, but you
-want to build the tools for somebody else to use. Or perhaps your
-GNU/Linux system is much faster than your Solaris system.
-
- A Canadian Cross build is most frequently used when building
-programs to run on a non-Unix system, such as DOS or Windows. It may
-be simpler to configure and build on a Unix system than to support the
-configuration machinery on a non-Unix system.
-
-\1f
-File: configure.info, Node: Canadian Cross Concepts, Next: Build Cross Host Tools, Prev: Canadian Cross Example, Up: Canadian Cross
-
-6.2 Canadian Cross Concepts
-===========================
-
-When building a Canadian Cross, there are at least two different systems
-involved: the system on which the tools are being built, and the system
-on which the tools will run.
-
- The system on which the tools are being built is called the "build"
-system.
-
- The system on which the tools will run is called the host system.
-
- For example, if you are building a Solaris program on a GNU/Linux
-system, as in the previous section, the build system would be GNU/Linux,
-and the host system would be Solaris.
-
- It is, of course, possible to build a cross compiler using a Canadian
-Cross (i.e., build a cross compiler using a cross compiler). In this
-case, the system for which the resulting cross compiler generates code
-is called the target system. (For a more complete discussion of host
-and target systems, *note Host and Target::).
-
- An example of building a cross compiler using a Canadian Cross would
-be building a Windows cross MIPS ELF compiler on a GNU/Linux system. In
-this case the build system would be GNU/Linux, the host system would be
-Windows, and the target system would be MIPS ELF.
-
- The name Canadian Cross comes from the case when the build, host, and
-target systems are all different. At the time that these issues were
-all being hashed out, Canada had three national political parties.
-
-\1f
-File: configure.info, Node: Build Cross Host Tools, Next: Build and Host Options, Prev: Canadian Cross Concepts, Up: Canadian Cross
-
-6.3 Build Cross Host Tools
-==========================
-
-In order to configure a program for a Canadian Cross build, you must
-first build and install the set of cross tools you will use to build the
-program.
-
- These tools will be build cross host tools. That is, they will run
-on the build system, and will produce code that runs on the host system.
-
- It is easy to confuse the meaning of build and host here. Always
-remember that the build system is where you are doing the build, and the
-host system is where the resulting program will run. Therefore, you
-need a build cross host compiler.
-
- In general, you must have a complete cross environment in order to do
-the build. This normally means a cross compiler, cross assembler, and
-so forth, as well as libraries and include files for the host system.
-
-\1f
-File: configure.info, Node: Build and Host Options, Next: CCross not in Cygnus Tree, Prev: Build Cross Host Tools, Up: Canadian Cross
-
-6.4 Build and Host Options
-==========================
-
-When you run `configure', you must use both the `--build' and `--host'
-options.
-
- The `--build' option is used to specify the configuration name of
-the build system. This can normally be the result of running the
-`config.guess' shell script, and it is reasonable to use
-`--build=`config.guess`'.
-
- The `--host' option is used to specify the configuration name of the
-host system.
-
- As we explained earlier, `config.guess' is used to set the default
-value for the `--host' option (*note Using the Host Type::). We can
-now see that since `config.guess' returns the type of system on which
-it is run, it really identifies the build system. Since the host
-system is normally the same as the build system (i.e., people do not
-normally build using a cross compiler), it is reasonable to use the
-result of `config.guess' as the default for the host system when the
-`--host' option is not used.
-
- It might seem that if the `--host' option were used without the
-`--build' option that the configure script could run `config.guess' to
-determine the build system, and presume a Canadian Cross if the result
-of `config.guess' differed from the `--host' option. However, for
-historical reasons, some configure scripts are routinely run using an
-explicit `--host' option, rather than using the default from
-`config.guess'. As noted earlier, it is difficult or impossible to
-reliably compare configuration names (*note Using the Target Type::).
-Therefore, by convention, if the `--host' option is used, but the
-`--build' option is not used, then the build system defaults to the
-host system.
-
-\1f
-File: configure.info, Node: CCross not in Cygnus Tree, Next: CCross in Cygnus Tree, Prev: Build and Host Options, Up: Canadian Cross
-
-6.5 Canadian Cross not in Cygnus Tree.
-======================================
-
-If you are not using the Cygnus tree, you must explicitly specify the
-cross tools which you want to use to build the program. This is done by
-setting environment variables before running the `configure' script.
-
- You must normally set at least the environment variables `CC', `AR',
-and `RANLIB' to the cross tools which you want to use to build.
-
- For some programs, you must set additional cross tools as well, such
-as `AS', `LD', or `NM'.
-
- You would set these environment variables to the build cross tools
-which you are going to use.
-
- For example, if you are building a Solaris program on a GNU/Linux
-system, and your GNU/Linux cross Solaris compiler were named
-`solaris-gcc', then you would set the environment variable `CC' to
-`solaris-gcc'.
-
-\1f
-File: configure.info, Node: CCross in Cygnus Tree, Next: Supporting Canadian Cross, Prev: CCross not in Cygnus Tree, Up: Canadian Cross
-
-6.6 Canadian Cross in Cygnus Tree
-=================================
-
-This section describes configuring and building a Canadian Cross when
-using the Cygnus tree.
-
-* Menu:
-
-* Standard Cygnus CCross:: Building a Normal Program.
-* Cross Cygnus CCross:: Building a Cross Program.
-
-\1f
-File: configure.info, Node: Standard Cygnus CCross, Next: Cross Cygnus CCross, Up: CCross in Cygnus Tree
-
-6.6.1 Building a Normal Program
--------------------------------
-
-When configuring a Canadian Cross in the Cygnus tree, all the
-appropriate environment variables are automatically set to `HOST-TOOL',
-where HOST is the value used for the `--host' option, and TOOL is the
-name of the tool (e.g., `gcc', `as', etc.). These tools must be on
-your `PATH'.
-
- Adding a prefix of HOST will give the usual name for the build cross
-host tools. To see this, consider that when these cross tools were
-built, they were configured to run on the build system and to produce
-code for the host system. That is, they were configured with a
-`--target' option that is the same as the system which we are now
-calling the host. Recall that the default name for installed cross
-tools uses the target system as a prefix (*note Using the Target
-Type::). Since that is the system which we are now calling the host,
-HOST is the right prefix to use.
-
- For example, if you configure with `--build=i386-linux-gnu' and
-`--host=solaris', then the Cygnus tree will automatically default to
-using the compiler `solaris-gcc'. You must have previously built and
-installed this compiler, probably by doing a build with no `--host'
-option and with a `--target' option of `solaris'.
-
-\1f
-File: configure.info, Node: Cross Cygnus CCross, Prev: Standard Cygnus CCross, Up: CCross in Cygnus Tree
-
-6.6.2 Building a Cross Program
-------------------------------
-
-There are additional considerations if you want to build a cross
-compiler, rather than a native compiler, in the Cygnus tree using a
-Canadian Cross.
-
- When you build a cross compiler using the Cygnus tree, then the
-target libraries will normally be built with the newly built target
-compiler (*note Host and Target Libraries::). However, this will not
-work when building with a Canadian Cross. This is because the newly
-built target compiler will be a program which runs on the host system,
-and therefore will not be able to run on the build system.
-
- Therefore, when building a cross compiler with the Cygnus tree, you
-must first install a set of build cross target tools. These tools will
-be used when building the target libraries.
-
- Note that this is not a requirement of a Canadian Cross in general.
-For example, it would be possible to build just the host cross target
-tools on the build system, to copy the tools to the host system, and to
-build the target libraries on the host system. The requirement for
-build cross target tools is imposed by the Cygnus tree, which expects
-to be able to build both host programs and target libraries in a single
-`configure'/`make' step. Because it builds these in a single step, it
-expects to be able to build the target libraries on the build system,
-which means that it must use a build cross target toolchain.
-
- For example, suppose you want to build a Windows cross MIPS ELF
-compiler on a GNU/Linux system. You must have previously installed
-both a GNU/Linux cross Windows compiler and a GNU/Linux cross MIPS ELF
-compiler.
-
- In order to build the Windows (configuration name `i386-cygwin32')
-cross MIPS ELF (configure name `mips-elf') compiler, you might execute
-the following commands (long command lines are broken across lines with
-a trailing backslash as a continuation character).
-
- mkdir linux-x-cygwin32
- cd linux-x-cygwin32
- SRCDIR/configure --target i386-cygwin32 --prefix=INSTALLDIR \
- --exec-prefix=INSTALLDIR/H-i386-linux
- make
- make install
- cd ..
- mkdir linux-x-mips-elf
- cd linux-x-mips-elf
- SRCDIR/configure --target mips-elf --prefix=INSTALLDIR \
- --exec-prefix=INSTALLDIR/H-i386-linux
- make
- make install
- cd ..
- mkdir cygwin32-x-mips-elf
- cd cygwin32-x-mips-elf
- SRCDIR/configure --build=i386-linux-gnu --host=i386-cygwin32 \
- --target=mips-elf --prefix=WININSTALLDIR \
- --exec-prefix=WININSTALLDIR/H-i386-cygwin32
- make
- make install
-
- You would then copy the contents of WININSTALLDIR over to the
-Windows machine, and run the resulting programs.
-
-\1f
-File: configure.info, Node: Supporting Canadian Cross, Prev: CCross in Cygnus Tree, Up: Canadian Cross
-
-6.7 Supporting Canadian Cross
-=============================
-
-If you want to make it possible to build a program you are developing
-using a Canadian Cross, you must take some care when writing your
-configure and make rules. Simple cases will normally work correctly.
-However, it is not hard to write configure and make tests which will
-fail in a Canadian Cross.
-
-* Menu:
-
-* CCross in Configure:: Supporting Canadian Cross in Configure Scripts.
-* CCross in Make:: Supporting Canadian Cross in Makefiles.
-
-\1f
-File: configure.info, Node: CCross in Configure, Next: CCross in Make, Up: Supporting Canadian Cross
-
-6.7.1 Supporting Canadian Cross in Configure Scripts
-----------------------------------------------------
-
-In a `configure.in' file, after calling `AC_PROG_CC', you can find out
-whether this is a Canadian Cross configure by examining the shell
-variable `cross_compiling'. In a Canadian Cross, which means that the
-compiler is a cross compiler, `cross_compiling' will be `yes'. In a
-normal configuration, `cross_compiling' will be `no'.
-
- You ordinarily do not need to know the type of the build system in a
-configure script. However, if you do need that information, you can get
-it by using the macro `AC_CANONICAL_SYSTEM', the same macro that is
-used to determine the target system. This macro will set the variables
-`build', `build_alias', `build_cpu', `build_vendor', and `build_os',
-which correspond to the similar `target' and `host' variables, except
-that they describe the build system.
-
- When writing tests in `configure.in', you must remember that you
-want to test the host environment, not the build environment.
-
- Macros like `AC_CHECK_FUNCS' which use the compiler will test the
-host environment. That is because the tests will be done by running the
-compiler, which is actually a build cross host compiler. If the
-compiler can find the function, that means that the function is present
-in the host environment.
-
- Tests like `test -f /dev/ptyp0', on the other hand, will test the
-build environment. Remember that the configure script is running on the
-build system, not the host system. If your configure scripts examines
-files, those files will be on the build system. Whatever you determine
-based on those files may or may not be the case on the host system.
-
- Most autoconf macros will work correctly for a Canadian Cross. The
-main exception is `AC_TRY_RUN'. This macro tries to compile and run a
-test program. This will fail in a Canadian Cross, because the program
-will be compiled for the host system, which means that it will not run
-on the build system.
-
- The `AC_TRY_RUN' macro provides an optional argument to tell the
-configure script what to do in a Canadian Cross. If that argument is
-not present, you will get a warning when you run `autoconf':
- warning: AC_TRY_RUN called without default to allow cross compiling
- This tells you that the resulting `configure' script will not work
-with a Canadian Cross.
-
- In some cases while it may better to perform a test at configure
-time, it is also possible to perform the test at run time. In such a
-case you can use the cross compiling argument to `AC_TRY_RUN' to tell
-your program that the test could not be performed at configure time.
-
- There are a few other autoconf macros which will not work correctly
-with a Canadian Cross: a partial list is `AC_FUNC_GETPGRP',
-`AC_FUNC_SETPGRP', `AC_FUNC_SETVBUF_REVERSED', and
-`AC_SYS_RESTARTABLE_SYSCALLS'. The `AC_CHECK_SIZEOF' macro is
-generally not very useful with a Canadian Cross; it permits an optional
-argument indicating the default size, but there is no way to know what
-the correct default should be.
-
-\1f
-File: configure.info, Node: CCross in Make, Prev: CCross in Configure, Up: Supporting Canadian Cross
-
-6.7.2 Supporting Canadian Cross in Makefiles.
----------------------------------------------
-
-The main Canadian Cross issue in a `Makefile' arises when you want to
-use a subsidiary program to generate code or data which you will then
-include in your real program.
-
- If you compile this subsidiary program using `$(CC)' in the usual
-way, you will not be able to run it. This is because `$(CC)' will
-build a program for the host system, but the program is being built on
-the build system.
-
- You must instead use a compiler for the build system, rather than the
-host system. In the Cygnus tree, this make variable `$(CC_FOR_BUILD)'
-will hold a compiler for the build system.
-
- Note that you should not include `config.h' in a file you are
-compiling with `$(CC_FOR_BUILD)'. The `configure' script will build
-`config.h' with information for the host system. However, you are
-compiling the file using a compiler for the build system (a native
-compiler). Subsidiary programs are normally simple filters which do no
-user interaction, and it is normally possible to write them in a highly
-portable fashion so that the absence of `config.h' is not crucial.
-
- The gcc `Makefile.in' shows a complex situation in which certain
-files, such as `rtl.c', must be compiled into both subsidiary programs
-run on the build system and into the final program. This approach may
-be of interest for advanced build system hackers. Note that the build
-system compiler is rather confusingly called `HOST_CC'.
-
-\1f
-File: configure.info, Node: Cygnus Configure, Next: Multilibs, Prev: Canadian Cross, Up: Top
-
-7 Cygnus Configure
-******************
-
-The Cygnus configure script predates autoconf. All of its interesting
-features have been incorporated into autoconf. No new programs should
-be written to use the Cygnus configure script.
-
- However, the Cygnus configure script is still used in a few places:
-at the top of the Cygnus tree and in a few target libraries in the
-Cygnus tree. Until those uses have been replaced with autoconf, some
-brief notes are appropriate here. This is not complete documentation,
-but it should be possible to use this as a guide while examining the
-scripts themselves.
-
-* Menu:
-
-* Cygnus Configure Basics:: Cygnus Configure Basics.
-* Cygnus Configure in C++ Libraries:: Cygnus Configure in C++ Libraries.
-
-\1f
-File: configure.info, Node: Cygnus Configure Basics, Next: Cygnus Configure in C++ Libraries, Up: Cygnus Configure
-
-7.1 Cygnus Configure Basics
-===========================
-
-Cygnus configure does not use any generated files; there is no program
-corresponding to `autoconf'. Instead, there is a single shell script
-named `configure' which may be found at the top of the Cygnus tree.
-This shell script was written by hand; it was not generated by
-autoconf, and it is incorrect, and indeed harmful, to run `autoconf' in
-the top level of a Cygnus tree.
-
- Cygnus configure works in a particular directory by examining the
-file `configure.in' in that directory. That file is broken into four
-separate shell scripts.
-
- The first is the contents of `configure.in' up to a line that starts
-with `# per-host:'. This is the common part.
-
- The second is the rest of `configure.in' up to a line that starts
-with `# per-target:'. This is the per host part.
-
- The third is the rest of `configure.in' up to a line that starts
-with `# post-target:'. This is the per target part.
-
- The fourth is the remainder of `configure.in'. This is the post
-target part.
-
- If any of these comment lines are missing, the corresponding shell
-script is empty.
-
- Cygnus configure will first execute the common part. This must set
-the shell variable `srctrigger' to the name of a source file, to
-confirm that Cygnus configure is looking at the right directory. This
-may set the shell variables `package_makefile_frag' and
-`package_makefile_rules_frag'.
-
- Cygnus configure will next set the `build' and `host' shell
-variables, and execute the per host part. This may set the shell
-variable `host_makefile_frag'.
-
- Cygnus configure will next set the `target' variable, and execute
-the per target part. This may set the shell variable
-`target_makefile_frag'.
-
- Any of these scripts may set the `subdirs' shell variable. This
-variable is a list of subdirectories where a `Makefile.in' file may be
-found. Cygnus configure will automatically look for a `Makefile.in'
-file in the current directory. The `subdirs' shell variable is not
-normally used, and I believe that the only directory which uses it at
-present is `newlib'.
-
- For each `Makefile.in', Cygnus configure will automatically create a
-`Makefile' by adding definitions for `make' variables such as `host'
-and `target', and automatically editing the values of `make' variables
-such as `prefix' if they are present.
-
- Also, if any of the `makefile_frag' shell variables are set, Cygnus
-configure will interpret them as file names relative to either the
-working directory or the source directory, and will read the contents of
-the file into the generated `Makefile'. The file contents will be read
-in after the first line in `Makefile.in' which starts with `####'.
-
- These `Makefile' fragments are used to customize behaviour for a
-particular host or target. They serve to select particular files to
-compile, and to define particular preprocessor macros by providing
-values for `make' variables which are then used during compilation.
-Cygnus configure, unlike autoconf, normally does not do feature tests,
-and normally requires support to be added manually for each new host.
-
- The `Makefile' fragment support is similar to the autoconf
-`AC_SUBST_FILE' macro.
-
- After creating each `Makefile', the post target script will be run
-(i.e., it may be run several times). This script may further customize
-the `Makefile'. When it is run, the shell variable `Makefile' will
-hold the name of the `Makefile', including the appropriate directory
-component.
-
- Like an autoconf generated `configure' script, Cygnus configure will
-create a file named `config.status' which, when run, will automatically
-recreate the configuration. The `config.status' file will simply
-execute the Cygnus configure script again with the appropriate
-arguments.
-
- Any of the parts of `configure.in' may set the shell variables
-`files' and `links'. Cygnus configure will set up symlinks from the
-names in `links' to the files named in `files'. This is similar to the
-autoconf `AC_LINK_FILES' macro.
-
- Finally, any of the parts of `configure.in' may set the shell
-variable `configdirs' to a set of subdirectories. If it is set, Cygnus
-configure will recursively run the configure process in each
-subdirectory. If the subdirectory uses Cygnus configure, it will
-contain a `configure.in' file but no `configure' file, in which case
-Cygnus configure will invoke itself recursively. If the subdirectory
-has a `configure' file, Cygnus configure assumes that it is an autoconf
-generated `configure' script, and simply invokes it directly.
-
-\1f
-File: configure.info, Node: Cygnus Configure in C++ Libraries, Prev: Cygnus Configure Basics, Up: Cygnus Configure
-
-7.2 Cygnus Configure in C++ Libraries
-=====================================
-
-The C++ library configure system, written by Per Bothner, deserves
-special mention. It uses Cygnus configure, but it does feature testing
-like that done by autoconf generated `configure' scripts. This
-approach is used in the libraries `libio', `libstdc++', and `libg++'.
-
- Most of the `Makefile' information is written out by the shell
-script `libio/config.shared'. Each `configure.in' file sets certain
-shell variables, and then invokes `config.shared' to create two package
-`Makefile' fragments. These fragments are then incorporated into the
-resulting `Makefile' by the Cygnus configure script.
-
- The file `_G_config.h' is created in the `libio' object directory by
-running the shell script `libio/gen-params'. This shell script uses
-feature tests to define macros and typedefs in `_G_config.h'.
-
-\1f
-File: configure.info, Node: Multilibs, Next: FAQ, Prev: Cygnus Configure, Up: Top
-
-8 Multilibs
-***********
-
-For some targets gcc may have different processor requirements depending
-upon command line options. An obvious example is the `-msoft-float'
-option supported on several processors. This option means that the
-floating point registers are not available, which means that floating
-point operations must be done by calling an emulation subroutine rather
-than by using machine instructions.
-
- For such options, gcc is often configured to compile target libraries
-twice: once with `-msoft-float' and once without. When gcc compiles
-target libraries more than once, the resulting libraries are called
-"multilibs".
-
- Multilibs are not really part of the GNU configure and build system,
-but we discuss them here since they require support in the `configure'
-scripts and `Makefile's used for target libraries.
-
-* Menu:
-
-* Multilibs in gcc:: Multilibs in gcc.
-* Multilibs in Target Libraries:: Multilibs in Target Libraries.
-
-\1f
-File: configure.info, Node: Multilibs in gcc, Next: Multilibs in Target Libraries, Up: Multilibs
-
-8.1 Multilibs in gcc
-====================
-
-In gcc, multilibs are defined by setting the variable
-`MULTILIB_OPTIONS' in the target `Makefile' fragment. Several other
-`MULTILIB' variables may also be defined there. *Note The Target
-Makefile Fragment: (gcc)Target Fragment.
-
- If you have built gcc, you can see what multilibs it uses by running
-it with the `-print-multi-lib' option. The output `.;' means that no
-multilibs are used. In general, the output is a sequence of lines, one
-per multilib. The first part of each line, up to the `;', is the name
-of the multilib directory. The second part is a list of compiler
-options separated by `@' characters.
-
- Multilibs are built in a tree of directories. The top of the tree,
-represented by `.' in the list of multilib directories, is the default
-library to use when no special compiler options are used. The
-subdirectories of the tree hold versions of the library to use when
-particular compiler options are used.
-
-\1f
-File: configure.info, Node: Multilibs in Target Libraries, Prev: Multilibs in gcc, Up: Multilibs
-
-8.2 Multilibs in Target Libraries
-=================================
-
-The target libraries in the Cygnus tree are automatically built with
-multilibs. That means that each library is built multiple times.
-
- This default is set in the top level `configure.in' file, by adding
-`--enable-multilib' to the list of arguments passed to configure when
-it is run for the target libraries (*note Host and Target Libraries::).
-
- Each target library uses the shell script `config-ml.in', written by
-Doug Evans, to prepare to build target libraries. This shell script is
-invoked after the `Makefile' has been created by the `configure'
-script. If multilibs are not enabled, it does nothing, otherwise it
-modifies the `Makefile' to support multilibs.
-
- The `config-ml.in' script makes one copy of the `Makefile' for each
-multilib in the appropriate subdirectory. When configuring in the
-source directory (which is not recommended), it will build a symlink
-tree of the sources in each subdirectory.
-
- The `config-ml.in' script sets several variables in the various
-`Makefile's. The `Makefile.in' must have definitions for these
-variables already; `config-ml.in' simply changes the existing values.
-The `Makefile' should use default values for these variables which will
-do the right thing in the subdirectories.
-
-`MULTISRCTOP'
- `config-ml.in' will set this to a sequence of `../' strings, where
- the number of strings is the number of multilib levels in the
- source tree. The default value should be the empty string.
-
-`MULTIBUILDTOP'
- `config-ml.in' will set this to a sequence of `../' strings, where
- the number of strings is number of multilib levels in the object
- directory. The default value should be the empty string. This
- will differ from `MULTISRCTOP' when configuring in the source tree
- (which is not recommended).
-
-`MULTIDIRS'
- In the top level `Makefile' only, `config-ml.in' will set this to
- the list of multilib subdirectories. The default value should be
- the empty string.
-
-`MULTISUBDIR'
- `config-ml.in' will set this to the installed subdirectory name to
- use for this subdirectory, with a leading `/'. The default value
- shold be the empty string.
-
-`MULTIDO'
-`MULTICLEAN'
- In the top level `Makefile' only, `config-ml.in' will set these
- variables to commands to use when doing a recursive make. These
- variables should both default to the string `true', so that by
- default nothing happens.
-
- All references to the parent of the source directory should use the
-variable `MULTISRCTOP'. Instead of writing `$(srcdir)/..', you must
-write `$(srcdir)/$(MULTISRCTOP)..'.
-
- Similarly, references to the parent of the object directory should
-use the variable `MULTIBUILDTOP'.
-
- In the installation target, the libraries should be installed in the
-subdirectory `MULTISUBDIR'. Instead of installing
-`$(libdir)/libfoo.a', install `$(libdir)$(MULTISUBDIR)/libfoo.a'.
-
- The `config-ml.in' script also modifies the top level `Makefile' to
-add `multi-do' and `multi-clean' targets which are used when building
-multilibs.
-
- The default target of the `Makefile' should include the following
-command:
- @$(MULTIDO) $(FLAGS_TO_PASS) DO=all multi-do
- This assumes that `$(FLAGS_TO_PASS)' is defined as a set of
-variables to pass to a recursive invocation of `make'. This will build
-all the multilibs. Note that the default value of `MULTIDO' is `true',
-so by default this command will do nothing. It will only do something
-in the top level `Makefile' if multilibs were enabled.
-
- The `install' target of the `Makefile' should include the following
-command:
- @$(MULTIDO) $(FLAGS_TO_PASS) DO=install multi-do
-
- In general, any operation, other than clean, which should be
-performed on all the multilibs should use a `$(MULTIDO)' line, setting
-the variable `DO' to the target of each recursive call to `make'.
-
- The `clean' targets (`clean', `mostlyclean', etc.) should use
-`$(MULTICLEAN)'. For example, the `clean' target should do this:
- @$(MULTICLEAN) DO=clean multi-clean
-
-\1f
-File: configure.info, Node: FAQ, Next: Index, Prev: Multilibs, Up: Top
-
-9 Frequently Asked Questions
-****************************
-
-Which do I run first, `autoconf' or `automake'?
- Except when you first add autoconf or automake support to a
- package, you shouldn't run either by hand. Instead, configure
- with the `--enable-maintainer-mode' option, and let `make' take
- care of it.
-
-`autoconf' says something about undefined macros.
- This means that you have macros in your `configure.in' which are
- not defined by `autoconf'. You may be using an old version of
- `autoconf'; try building and installing a newer one. Make sure the
- newly installled `autoconf' is first on your `PATH'. Also, see
- the next question.
-
-My `configure' script has stuff like `CY_GNU_GETTEXT' in it.
- This means that you have macros in your `configure.in' which should
- be defined in your `aclocal.m4' file, but aren't. This usually
- means that `aclocal' was not able to appropriate definitions of the
- macros. Make sure that you have installed all the packages you
- need. In particular, make sure that you have installed libtool
- (this is where `AM_PROG_LIBTOOL' is defined) and gettext (this is
- where `CY_GNU_GETTEXT' is defined, at least in the Cygnus version
- of gettext).
-
-My `Makefile' has `@' characters in it.
- This may mean that you tried to use an autoconf substitution in
- your `Makefile.in' without adding the appropriate `AC_SUBST' call
- to your `configure' script. Or it may just mean that you need to
- rebuild `Makefile' in your build directory. To rebuild `Makefile'
- from `Makefile.in', run the shell script `config.status' with no
- arguments. If you need to force `configure' to run again, first
- run `config.status --recheck'. These runs are normally done
- automatically by `Makefile' targets, but if your `Makefile' has
- gotten messed up you'll need to help them along.
-
-Why do I have to run both `config.status --recheck' and `config.status'?
- Normally, you don't; they will be run automatically by `Makefile'
- targets. If you do need to run them, use `config.status --recheck'
- to run the `configure' script again with the same arguments as the
- first time you ran it. Use `config.status' (with no arguments) to
- regenerate all files (`Makefile', `config.h', etc.) based on the
- results of the configure script. The two cases are separate
- because it isn't always necessary to regenerate all the files
- after running `config.status --recheck'. The `Makefile' targets
- generated by automake will use the environment variables
- `CONFIG_FILES' and `CONFIG_HEADERS' to only regenerate files as
- they are needed.
-
-What is the Cygnus tree?
- The Cygnus tree is used for various packages including gdb, the GNU
- binutils, and egcs. It is also, of course, used for Cygnus
- releases. It is the build system which was developed at Cygnus,
- using the Cygnus configure script. It permits building many
- different packages with a single configure and make. The
- configure scripts in the tree are being converted to autoconf, but
- the general build structure remains intact.
-
-Why do I have to keep rebuilding and reinstalling the tools?
- I know, it's a pain. Unfortunately, there are bugs in the tools
- themselves which need to be fixed, and each time that happens
- everybody who uses the tools need to reinstall new versions of
- them. I don't know if there is going to be a clever fix until the
- tools stabilize.
-
-Why not just have a Cygnus tree `make' target to update the tools?
- The tools unfortunately need to be installed before they can be
- used. That means that they must be built using an appropriate
- prefix, and it seems unwise to assume that every configuration
- uses an appropriate prefix. It might be possible to make them
- work in place, or it might be possible to install them in some
- subdirectory; so far these approaches have not been implemented.
-
-\1f
-File: configure.info, Node: Index, Prev: FAQ, Up: Top
-
-Index
-*****
-
-\0\b[index\0\b]
-* Menu:
-
-* --build option: Build and Host Options.
- (line 9)
-* --host option: Build and Host Options.
- (line 14)
-* --target option: Specifying the Target.
- (line 10)
-* _GNU_SOURCE: Write configure.in. (line 134)
-* AC_CANONICAL_HOST: Using the Host Type. (line 10)
-* AC_CANONICAL_SYSTEM: Using the Target Type.
- (line 6)
-* AC_CONFIG_HEADER: Write configure.in. (line 66)
-* AC_EXEEXT: Write configure.in. (line 86)
-* AC_INIT: Write configure.in. (line 38)
-* AC_OUTPUT: Write configure.in. (line 142)
-* AC_PREREQ: Write configure.in. (line 42)
-* AC_PROG_CC: Write configure.in. (line 103)
-* AC_PROG_CXX: Write configure.in. (line 117)
-* acconfig.h: Written Developer Files.
- (line 27)
-* acconfig.h, writing: Write acconfig.h. (line 6)
-* acinclude.m4: Written Developer Files.
- (line 37)
-* aclocal.m4: Generated Developer Files.
- (line 33)
-* AM_CONFIG_HEADER: Write configure.in. (line 53)
-* AM_DISABLE_SHARED: Write configure.in. (line 127)
-* AM_EXEEXT: Write configure.in. (line 86)
-* AM_INIT_AUTOMAKE: Write configure.in. (line 48)
-* AM_MAINTAINER_MODE: Write configure.in. (line 70)
-* AM_PROG_LIBTOOL: Write configure.in. (line 122)
-* AM_PROG_LIBTOOL in configure: FAQ. (line 19)
-* build option: Build and Host Options.
- (line 9)
-* building with a cross compiler: Canadian Cross. (line 6)
-* canadian cross: Canadian Cross. (line 6)
-* canadian cross in configure: CCross in Configure. (line 6)
-* canadian cross in cygnus tree: CCross in Cygnus Tree.
- (line 6)
-* canadian cross in makefile: CCross in Make. (line 6)
-* canadian cross, configuring: Build and Host Options.
- (line 6)
-* canonical system names: Configuration Names. (line 6)
-* config.cache: Build Files Description.
- (line 28)
-* config.h: Build Files Description.
- (line 23)
-* config.h.in: Generated Developer Files.
- (line 45)
-* config.in: Generated Developer Files.
- (line 45)
-* config.status: Build Files Description.
- (line 9)
-* config.status --recheck: FAQ. (line 40)
-* configuration names: Configuration Names. (line 6)
-* configuration triplets: Configuration Names. (line 6)
-* configure: Generated Developer Files.
- (line 21)
-* configure build system: Build and Host Options.
- (line 9)
-* configure host: Build and Host Options.
- (line 14)
-* configure target: Specifying the Target.
- (line 10)
-* configure.in: Written Developer Files.
- (line 9)
-* configure.in, writing: Write configure.in. (line 6)
-* configuring a canadian cross: Build and Host Options.
- (line 6)
-* cross compiler: Cross Compilation Concepts.
- (line 6)
-* cross compiler, building with: Canadian Cross. (line 6)
-* cross tools: Cross Compilation Tools.
- (line 6)
-* CY_GNU_GETTEXT in configure: FAQ. (line 19)
-* cygnus configure: Cygnus Configure. (line 6)
-* goals: Goals. (line 6)
-* history: History. (line 6)
-* host names: Configuration Names. (line 6)
-* host option: Build and Host Options.
- (line 14)
-* host system: Host and Target. (line 6)
-* host triplets: Configuration Names. (line 6)
-* HOST_CC: CCross in Make. (line 27)
-* libg++ configure: Cygnus Configure in C++ Libraries.
- (line 6)
-* libio configure: Cygnus Configure in C++ Libraries.
- (line 6)
-* libstdc++ configure: Cygnus Configure in C++ Libraries.
- (line 6)
-* Makefile: Build Files Description.
- (line 18)
-* Makefile, garbage characters: FAQ. (line 29)
-* Makefile.am: Written Developer Files.
- (line 18)
-* Makefile.am, writing: Write Makefile.am. (line 6)
-* Makefile.in: Generated Developer Files.
- (line 26)
-* multilibs: Multilibs. (line 6)
-* stamp-h: Build Files Description.
- (line 41)
-* stamp-h.in: Generated Developer Files.
- (line 54)
-* system names: Configuration Names. (line 6)
-* system types: Configuration Names. (line 6)
-* target option: Specifying the Target.
- (line 10)
-* target system: Host and Target. (line 6)
-* triplets: Configuration Names. (line 6)
-* undefined macros: FAQ. (line 12)
-
-
-\1f
-Tag Table:
-Node: Top\7f978
-Node: Introduction\7f1506
-Node: Goals\7f2588
-Node: Tools\7f3312
-Node: History\7f4306
-Node: Building\7f7304
-Node: Getting Started\7f10567
-Node: Write configure.in\7f11080
-Node: Write Makefile.am\7f18331
-Node: Write acconfig.h\7f21508
-Node: Generate files\7f23045
-Node: Getting Started Example\7f25011
-Node: Getting Started Example 1\7f25766
-Node: Getting Started Example 2\7f27687
-Node: Getting Started Example 3\7f30682
-Node: Generate Files in Example\7f33046
-Node: Files\7f34136
-Node: Developer Files\7f34747
-Node: Developer Files Picture\7f35127
-Node: Written Developer Files\7f36415
-Node: Generated Developer Files\7f38967
-Node: Build Files\7f42111
-Node: Build Files Picture\7f42772
-Node: Build Files Description\7f43536
-Node: Support Files\7f45542
-Node: Configuration Names\7f48424
-Node: Configuration Name Definition\7f48924
-Node: Using Configuration Names\7f51247
-Node: Cross Compilation Tools\7f53217
-Node: Cross Compilation Concepts\7f53908
-Node: Host and Target\7f54876
-Node: Using the Host Type\7f56377
-Node: Specifying the Target\7f57726
-Node: Using the Target Type\7f58515
-Node: Cross Tools in the Cygnus Tree\7f61946
-Node: Host and Target Libraries\7f63003
-Node: Target Library Configure Scripts\7f66752
-Node: Make Targets in Cygnus Tree\7f69844
-Node: Target libiberty\7f71192
-Node: Canadian Cross\7f72579
-Node: Canadian Cross Example\7f73420
-Node: Canadian Cross Concepts\7f74539
-Node: Build Cross Host Tools\7f76051
-Node: Build and Host Options\7f77003
-Node: CCross not in Cygnus Tree\7f78789
-Node: CCross in Cygnus Tree\7f79767
-Node: Standard Cygnus CCross\7f80188
-Node: Cross Cygnus CCross\7f81552
-Node: Supporting Canadian Cross\7f84352
-Node: CCross in Configure\7f84967
-Node: CCross in Make\7f88135
-Node: Cygnus Configure\7f89738
-Node: Cygnus Configure Basics\7f90573
-Node: Cygnus Configure in C++ Libraries\7f95251
-Node: Multilibs\7f96258
-Node: Multilibs in gcc\7f97303
-Node: Multilibs in Target Libraries\7f98381
-Node: FAQ\7f102572
-Node: Index\7f106672
-\1f
-End Tag Table
projects / msp430-binutils.git / blobdiff