256 lines
11 KiB
HTML
256 lines
11 KiB
HTML
|
<html lang="en">
|
||
|
|
<head>
|
||
|
|
<title>Installing GCC: Building</title>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html">
|
||
|
|
<meta name="description" content="Installing GCC: Building">
|
||
|
|
<meta name="generator" content="makeinfo 4.6">
|
||
|
|
<!--
|
||
|
|
Copyright © 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
|
||
|
|
1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
|
||
|
|
<br><p>
|
||
|
|
<p>Permission is granted to copy, distribute and/or modify this document
|
||
|
|
under the terms of the GNU Free Documentation License, Version 1.2 or
|
||
|
|
any later version published by the Free Software Foundation; with no
|
||
|
|
Invariant Sections, the Front-Cover texts being (a) (see below), and
|
||
|
|
with the Back-Cover Texts being (b) (see below). A copy of the
|
||
|
|
license is included in the section entitled "<a href="./gfdl.html">GNU Free Documentation License</a>".
|
||
|
|
|
||
|
|
<p>(a) The FSF's Front-Cover Text is:
|
||
|
|
|
||
|
|
<p>A GNU Manual
|
||
|
|
|
||
|
|
<p>(b) The FSF's Back-Cover Text is:
|
||
|
|
|
||
|
|
<p>You have freedom to copy and modify this GNU Manual, like GNU
|
||
|
|
software. Copies published by the Free Software Foundation raise
|
||
|
|
funds for GNU development.-->
|
||
|
|
<meta http-equiv="Content-Style-Type" content="text/css">
|
||
|
|
<style type="text/css"><!--
|
||
|
|
pre.display { font-family:inherit }
|
||
|
|
pre.format { font-family:inherit }
|
||
|
|
pre.smalldisplay { font-family:inherit; font-size:smaller }
|
||
|
|
pre.smallformat { font-family:inherit; font-size:smaller }
|
||
|
|
pre.smallexample { font-size:smaller }
|
||
|
|
pre.smalllisp { font-size:smaller }
|
||
|
|
--></style>
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
<h1 class="settitle">Installing GCC: Building</h1>
|
||
|
|
Now that GCC is configured, you are ready to build the compiler and
|
||
|
|
runtime libraries.
|
||
|
|
|
||
|
|
<p>We <strong>highly</strong> recommend that GCC be built using GNU make;
|
||
|
|
other versions may work, then again they might not.
|
||
|
|
GNU make is required for compiling GNAT (the Ada compiler) and the Java
|
||
|
|
runtime library.
|
||
|
|
|
||
|
|
<p>(For example, many broken versions of make will fail if you use the
|
||
|
|
recommended setup where <var>objdir</var> is different from <var>srcdir</var>.
|
||
|
|
Other broken versions may recompile parts of the compiler when
|
||
|
|
installing the compiler.)
|
||
|
|
|
||
|
|
<p>Some commands executed when making the compiler may fail (return a
|
||
|
|
nonzero status) and be ignored by <code>make</code>. These failures, which
|
||
|
|
are often due to files that were not found, are expected, and can safely
|
||
|
|
be ignored.
|
||
|
|
|
||
|
|
<p>It is normal to have compiler warnings when compiling certain files.
|
||
|
|
Unless you are a GCC developer, you can generally ignore these warnings
|
||
|
|
unless they cause compilation to fail.
|
||
|
|
|
||
|
|
<p>On certain old systems, defining certain environment variables such as
|
||
|
|
<code>CC</code> can interfere with the functioning of <code>make</code>.
|
||
|
|
|
||
|
|
<p>If you encounter seemingly strange errors when trying to build the
|
||
|
|
compiler in a directory other than the source directory, it could be
|
||
|
|
because you have previously configured the compiler in the source
|
||
|
|
directory. Make sure you have done all the necessary preparations.
|
||
|
|
|
||
|
|
<p>If you build GCC on a BSD system using a directory stored in an old System
|
||
|
|
V file system, problems may occur in running <code>fixincludes</code> if the
|
||
|
|
System V file system doesn't support symbolic links. These problems
|
||
|
|
result in a failure to fix the declaration of <code>size_t</code> in
|
||
|
|
<code>sys/types.h</code>. If you find that <code>size_t</code> is a signed type and
|
||
|
|
that type mismatches occur, this could be the cause.
|
||
|
|
|
||
|
|
<p>The solution is not to use such a directory for building GCC.
|
||
|
|
|
||
|
|
<p>When building from CVS or snapshots, or if you modify parser sources,
|
||
|
|
you need the Bison parser generator installed. Any version 1.25 or
|
||
|
|
later should work; older versions may also work. If you do not modify
|
||
|
|
parser sources, releases contain the Bison-generated files and you do
|
||
|
|
not need Bison installed to build them.
|
||
|
|
|
||
|
|
<p>When building from CVS or snapshots, or if you modify Texinfo
|
||
|
|
documentation, you need version 4.2 or later of Texinfo installed if you
|
||
|
|
want Info documentation to be regenerated. Releases contain Info
|
||
|
|
documentation pre-built for the unmodified documentation in the release.
|
||
|
|
|
||
|
|
<h3 class="section"><a name="TOC0"></a>Building a native compiler</h3>
|
||
|
|
|
||
|
|
<p>For a native build issue the command <code>make bootstrap</code>. This
|
||
|
|
will build the entire GCC system, which includes the following steps:
|
||
|
|
|
||
|
|
<ul>
|
||
|
|
<li>Build host tools necessary to build the compiler such as texinfo, bison,
|
||
|
|
gperf.
|
||
|
|
|
||
|
|
<li>Build target tools for use by the compiler such as binutils (bfd,
|
||
|
|
binutils, gas, gprof, ld, and opcodes)
|
||
|
|
if they have been individually linked
|
||
|
|
or moved into the top level GCC source tree before configuring.
|
||
|
|
|
||
|
|
<li>Perform a 3-stage bootstrap of the compiler.
|
||
|
|
|
||
|
|
<li>Perform a comparison test of the stage2 and stage3 compilers.
|
||
|
|
|
||
|
|
<li>Build runtime libraries using the stage3 compiler from the previous step.
|
||
|
|
|
||
|
|
</ul>
|
||
|
|
|
||
|
|
<p>If you are short on disk space you might consider <code>make
|
||
|
|
bootstrap-lean</code> instead. This is identical to <code>make
|
||
|
|
bootstrap</code> except that object files from the stage1 and
|
||
|
|
stage2 of the 3-stage bootstrap of the compiler are deleted as
|
||
|
|
soon as they are no longer needed.
|
||
|
|
|
||
|
|
<p>If you want to save additional space during the bootstrap and in
|
||
|
|
the final installation as well, you can build the compiler binaries
|
||
|
|
without debugging information as in the following example. This will save
|
||
|
|
roughly 40% of disk space both for the bootstrap and the final installation.
|
||
|
|
(Libraries will still contain debugging information.)
|
||
|
|
|
||
|
|
<pre class="example"> make CFLAGS='-O' LIBCFLAGS='-g -O2' \
|
||
|
|
LIBCXXFLAGS='-g -O2 -fno-implicit-templates' bootstrap
|
||
|
|
</pre>
|
||
|
|
|
||
|
|
<p>If you wish to use non-default GCC flags when compiling the stage2 and
|
||
|
|
stage3 compilers, set <code>BOOT_CFLAGS</code> on the command line when doing
|
||
|
|
<code>make bootstrap</code>. Non-default optimization flags are less well
|
||
|
|
tested here than the default of <code>-g -O2</code>, but should still work.
|
||
|
|
In a few cases, you may find that you need to specify special flags such
|
||
|
|
as <code>-msoft-float</code> here to complete the bootstrap; or, if the
|
||
|
|
native compiler miscompiles the stage1 compiler, you may need to work
|
||
|
|
around this, by choosing <code>BOOT_CFLAGS</code> to avoid the parts of the
|
||
|
|
stage1 compiler that were miscompiled, or by using <code>make
|
||
|
|
bootstrap4</code> to increase the number of stages of bootstrap.
|
||
|
|
|
||
|
|
<p>If you used the flag <code>--enable-languages=...</code> to restrict
|
||
|
|
the compilers to be built, only those you've actually enabled will be
|
||
|
|
built. This will of course only build those runtime libraries, for
|
||
|
|
which the particular compiler has been built. Please note,
|
||
|
|
that re-defining <code>LANGUAGES</code> when calling <code>make bootstrap</code>
|
||
|
|
<strong>does not</strong> work anymore!
|
||
|
|
|
||
|
|
<p>If the comparison of stage2 and stage3 fails, this normally indicates
|
||
|
|
that the stage2 compiler has compiled GCC incorrectly, and is therefore
|
||
|
|
a potentially serious bug which you should investigate and report. (On
|
||
|
|
a few systems, meaningful comparison of object files is impossible; they
|
||
|
|
always appear "different". If you encounter this problem, you will
|
||
|
|
need to disable comparison in the <code>Makefile</code>.)
|
||
|
|
|
||
|
|
<h3 class="section"><a name="TOC1"></a>Building a cross compiler</h3>
|
||
|
|
|
||
|
|
<p>We recommend reading the
|
||
|
|
<a href="http://www.objsw.com/CrossGCC/">crossgcc FAQ</a>
|
||
|
|
for information about building cross compilers.
|
||
|
|
|
||
|
|
<p>When building a cross compiler, it is not generally possible to do a
|
||
|
|
3-stage bootstrap of the compiler. This makes for an interesting problem
|
||
|
|
as parts of GCC can only be built with GCC.
|
||
|
|
|
||
|
|
<p>To build a cross compiler, we first recommend building and installing a
|
||
|
|
native compiler. You can then use the native GCC compiler to build the
|
||
|
|
cross compiler. The installed native compiler needs to be GCC version
|
||
|
|
2.95 or later.
|
||
|
|
|
||
|
|
<p>Assuming you have already installed a native copy of GCC and configured
|
||
|
|
your cross compiler, issue the command <code>make</code>, which performs the
|
||
|
|
following steps:
|
||
|
|
|
||
|
|
<ul>
|
||
|
|
<li>Build host tools necessary to build the compiler such as texinfo, bison,
|
||
|
|
gperf.
|
||
|
|
|
||
|
|
<li>Build target tools for use by the compiler such as binutils (bfd,
|
||
|
|
binutils, gas, gprof, ld, and opcodes)
|
||
|
|
if they have been individually linked or moved into the top level GCC source
|
||
|
|
tree before configuring.
|
||
|
|
|
||
|
|
<li>Build the compiler (single stage only).
|
||
|
|
|
||
|
|
<li>Build runtime libraries using the compiler from the previous step.
|
||
|
|
</ul>
|
||
|
|
|
||
|
|
<p>Note that if an error occurs in any step the make process will exit.
|
||
|
|
|
||
|
|
<h3 class="section"><a name="TOC2"></a>Building in parallel</h3>
|
||
|
|
|
||
|
|
<p>You can use <code>make bootstrap MAKE="make -j 2" -j 2</code>, or just
|
||
|
|
<code>make -j 2 bootstrap</code> for GNU Make 3.79 and above, instead of
|
||
|
|
<code>make bootstrap</code> to build GCC in parallel.
|
||
|
|
You can also specify a bigger number, and in most cases using a value
|
||
|
|
greater than the number of processors in your machine will result in
|
||
|
|
fewer and shorter I/O latency hits, thus improving overall throughput;
|
||
|
|
this is especially true for slow drives and network filesystems.
|
||
|
|
|
||
|
|
<h3 class="section"><a name="TOC3"></a>Building the Ada compiler</h3>
|
||
|
|
|
||
|
|
<p>In order to build GNAT, the Ada compiler, you need a working GNAT
|
||
|
|
compiler (GNAT version 3.13 or later, or GCC version 3.1 or later),
|
||
|
|
since the Ada front end is written in Ada (with some
|
||
|
|
GNAT-specific extensions), and GNU make.
|
||
|
|
|
||
|
|
<p>However, you do not need a full installation of GNAT, just the GNAT
|
||
|
|
binary <code>gnat1</code>, a copy of <code>gnatbind</code>, and a compiler driver
|
||
|
|
which can deal with Ada input (by invoking the <code>gnat1</code> binary).
|
||
|
|
You can specify this compiler driver by setting the <code>ADAC</code>
|
||
|
|
environment variable at the configure step. <code>configure</code> can
|
||
|
|
detect the driver automatically if it has got a common name such as
|
||
|
|
<code>gcc</code> or <code>gnatgcc</code>. Of course, you still need a working
|
||
|
|
C compiler (the compiler driver can be different or not).
|
||
|
|
<code>configure</code> does not test whether the GNAT installation works
|
||
|
|
and has a sufficiently recent version; if too old a GNAT version is
|
||
|
|
installed, the build will fail unless <code>--enable-languages</code> is
|
||
|
|
used to disable building the Ada front end.
|
||
|
|
|
||
|
|
<p>Additional build tools (such as <code>gnatmake</code>) or a working GNAT
|
||
|
|
run-time library installation are usually <em>not</em> required. However,
|
||
|
|
if you want to bootstrap the compiler using a minimal version of GNAT,
|
||
|
|
you have to issue the following commands before invoking <code>make
|
||
|
|
bootstrap</code> (this assumes that you start with an unmodified and consistent
|
||
|
|
source distribution):
|
||
|
|
|
||
|
|
<pre class="example"> cd <var>srcdir</var>/gcc/ada
|
||
|
|
touch treeprs.ads [es]info.h nmake.ad[bs]
|
||
|
|
</pre>
|
||
|
|
|
||
|
|
<p>At the moment, the GNAT library and several tools for GNAT are not built
|
||
|
|
by <code>make bootstrap</code>. You have to invoke
|
||
|
|
<code>make gnatlib_and_tools</code> in the <code></code><var>objdir</var><code>/gcc</code>
|
||
|
|
subdirectory before proceeding with the next steps.
|
||
|
|
|
||
|
|
<p>For example, you can build a native Ada compiler by issuing the
|
||
|
|
following commands (assuming <code>make</code> is GNU make):
|
||
|
|
|
||
|
|
<pre class="example"> cd <var>objdir</var>
|
||
|
|
<var>srcdir</var>/configure --enable-languages=c,ada
|
||
|
|
cd <var>srcdir</var>/gcc/ada
|
||
|
|
touch treeprs.ads [es]info.h nmake.ad[bs]
|
||
|
|
cd <var>objdir</var>
|
||
|
|
make bootstrap
|
||
|
|
cd gcc
|
||
|
|
make gnatlib_and_tools
|
||
|
|
cd ..
|
||
|
|
</pre>
|
||
|
|
|
||
|
|
<p>Currently, when compiling the Ada front end, you cannot use the parallel
|
||
|
|
build feature described in the previous section.
|
||
|
|
|
||
|
|
<hr />
|
||
|
|
<p>
|
||
|
|
<a href="./index.html">Return to the GCC Installation page</a>
|
||
|
|
|
||
|
|
</body></html>
|
||
|
|
|