OpenBSD-4.6/gnu/egcs/install/build.html
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<title>Installing GCC: Building</title>
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<h1 align="center">Installing GCC: Building</h1>
<p>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.</p>
<p>(For example, many broken versions of make will fail if you use the
recommended setup where <i>objdir</i> is different from <i>srcdir</i>.)
<h2>Building a native compiler</h2>
<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>
<li> Build target tools for use by the compiler such as binutils (bfd,
binutils, gas, gprof, ld, and opcodes)<br>
if they have been individually linked or moved into the top level GCC source
tree before configuring.</li>
<li>Perform a 3-stage bootstrap of the compiler.</li>
<li>Perform a comparison test of the stage2 and stage3 compilers.</li>
<li>Build runtime libraries using the stage3 compiler from the previous
step.</li>
</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 with "make CFLAGS='-O' LIBCFLAGS='-g
-O2' LIBCXXFLAGS='-g -O2 -fno-implicit-templates' bootstrap". This will save
roughly 40% of disk space both for the bootstrap and the final installation.
(Libraries will still contain debugging information.)
<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 LANGUAGES when calling `<code>make bootstrap</code>'
<b>*does not*</b> work anymore!
<h2>Building a cross compiler</h2>
<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.
<p>Assuming you have already installed a native copy of GCC and configured
your cross compiler, issue the command "make", which performs the
following steps:
<ul>
<li>Build host tools necessary to build the compiler such as texinfo, bison,
gperf.</li>
<li>Build target tools for use by the compiler such as binutils (bfd,
binutils, gas, gprof, ld, and opcodes)<br>
if they have been individually linked or moved into the top level GCC source
tree before configuring.</li>
<li>Build the compiler (single stage only).</li>
<li>Build runtime libraries using the compiler from the previous
step.</li>
</ul>
<p>Note that if an error occurs in any step the make process will exit.
<h2>Building in parallel</h2>
<p> If you have a multiprocessor system 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 just `<code>make bootstrap</code>'
when building GCC. You can use a bigger number instead of two if
you like. In most cases, it won't help to use a number bigger than
the number of processors in your machine.
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<p><a href="./index.html">Return to the GCC Installation page</a></p>
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