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diff --git a/gcc-4.3.1/INSTALL/build.html b/gcc-4.3.1/INSTALL/build.html new file mode 100644 index 000000000..c654aa1ca --- /dev/null +++ b/gcc-4.3.1/INSTALL/build.html @@ -0,0 +1,314 @@ +<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 4.11"> +<link title="Top" rel="top" href="#Top"> +<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> +<!-- +Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, +1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc. + + 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 "GNU Free Documentation License". + +(a) The FSF's Front-Cover Text is: + + A GNU Manual + +(b) The FSF's Back-Cover Text is: + + 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 } + span.sc { font-variant:small-caps } + span.roman { font-family:serif; font-weight:normal; } + span.sansserif { font-family:sans-serif; font-weight:normal; } +--></style> +</head> +<body> +<h1 class="settitle">Installing GCC: Building</h1> +<a name="index-Installing-GCC_003a-Building-1"></a> +Now that GCC is configured, you are ready to build the compiler and +runtime libraries. + + <p>Some commands executed when making the compiler may fail (return a +nonzero status) and be ignored by <samp><span class="command">make</span></samp>. 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. Developers should attempt to fix +any warnings encountered, however they can temporarily continue past +warnings-as-errors by specifying the configure flag +<samp><span class="option">--disable-werror</span></samp>. + + <p>On certain old systems, defining certain environment variables such as +<samp><span class="env">CC</span></samp> can interfere with the functioning of <samp><span class="command">make</span></samp>. + + <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 <samp><span class="command">fixincludes</span></samp> 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 +<samp><span class="file">sys/types.h</span></samp>. 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 SVN or snapshots and enabling the <code>treelang</code> +front end, or if you modify <samp><span class="file">*.y</span></samp> files, you need the Bison parser +generator installed. If you do not modify <samp><span class="file">*.y</span></samp> files, releases +contain the Bison-generated files and you do not need Bison installed +to build them. Note that most front ends now use hand-written parsers, +which can be modified with no need for Bison. + + <p>Similarly, when building from SVN or snapshots, or if you modify +<samp><span class="file">*.l</span></samp> files, you need the Flex lexical analyzer generator installed. +There is still one Flex-based lexical analyzer (part of the build +machinery, not of GCC itself) that is used even if you only build the +C front end. + + <p>When building from SVN or snapshots, or if you modify Texinfo +documentation, you need version 4.4 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>0.1 Building a native compiler</h3> + +<p>For a native build, the default configuration is to perform +a 3-stage bootstrap of the compiler when ‘<samp><span class="samp">make</span></samp>’ is invoked. +This will build the entire GCC system and ensure that it compiles +itself correctly. It can be disabled with the <samp><span class="option">--disable-bootstrap</span></samp> +parameter to ‘<samp><span class="samp">configure</span></samp>’, but bootstrapping is suggested because +the compiler will be tested more completely and could also have +better performance. + + <p>The bootstrapping process will complete the following steps: + + <ul> +<li>Build tools necessary to build the compiler. + + <li>Perform a 3-stage bootstrap of the compiler. This includes building +three times the 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 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 ‘<samp><span class="samp">make +bootstrap-lean</span></samp>’ instead. The sequence of compilation is the +same described above, but 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="smallexample"> 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 +‘<samp><span class="samp">make</span></samp>’. Non-default optimization flags are less well +tested here than the default of ‘<samp><span class="samp">-g -O2</span></samp>’, but should still work. +In a few cases, you may find that you need to specify special flags such +as <samp><span class="option">-msoft-float</span></samp> 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 ‘<samp><span class="samp">make +bootstrap4</span></samp>’ to increase the number of stages of bootstrap. + + <p>Note that using non-standard <code>CFLAGS</code> can cause bootstrap to fail +if these trigger a warning with the new compiler. For example using +‘<samp><span class="samp">-O2 -g -mcpu=i686</span></samp>’ on <code>i686-pc-linux-gnu</code> will cause bootstrap +failure as <samp><span class="option">-mcpu=</span></samp> is deprecated in 3.4.0 and above. + + <p>If you used the flag <samp><span class="option">--enable-languages=...</span></samp> 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 <samp><span class="env">LANGUAGES</span></samp> when calling ‘<samp><span class="samp">make</span></samp>’ +<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 <samp><span class="file">Makefile</span></samp>.) + + <p>If you do not want to bootstrap your compiler, you can configure with +<samp><span class="option">--disable-bootstrap</span></samp>. In particular cases, you may want to +bootstrap your compiler even if the target system is not the same as +the one you are building on: for example, you could build a +<code>powerpc-unknown-linux-gnu</code> toolchain on a +<code>powerpc64-unknown-linux-gnu</code> host. In this case, pass +<samp><span class="option">--enable-bootstrap</span></samp> to the configure script. + +<h3 class="section"><a name="TOC1"></a>0.2 Building a cross compiler</h3> + +<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>If the cross compiler is to be built with support for the Java +programming language and the ability to compile .java source files is +desired, the installed native compiler used to build the cross +compiler needs to be the same GCC version as the cross compiler. In +addition the cross compiler needs to be configured with +<samp><span class="option">--with-ecj-jar=...</span></samp>. + + <p>Assuming you have already installed a native copy of GCC and configured +your cross compiler, issue the command <samp><span class="command">make</span></samp>, which performs the +following steps: + + <ul> +<li>Build host tools necessary to build the compiler. + + <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. + + <p>If you are not building GNU binutils in the same source tree as GCC, +you will need a cross-assembler and cross-linker installed before +configuring GCC. Put them in the directory +<samp><var>prefix</var><span class="file">/</span><var>target</var><span class="file">/bin</span></samp>. Here is a table of the tools +you should put in this directory: + + <dl> +<dt><samp><span class="file">as</span></samp><dd>This should be the cross-assembler. + + <br><dt><samp><span class="file">ld</span></samp><dd>This should be the cross-linker. + + <br><dt><samp><span class="file">ar</span></samp><dd>This should be the cross-archiver: a program which can manipulate +archive files (linker libraries) in the target machine's format. + + <br><dt><samp><span class="file">ranlib</span></samp><dd>This should be a program to construct a symbol table in an archive file. +</dl> + + <p>The installation of GCC will find these programs in that directory, +and copy or link them to the proper place to for the cross-compiler to +find them when run later. + + <p>The easiest way to provide these files is to build the Binutils package. +Configure it with the same <samp><span class="option">--host</span></samp> and <samp><span class="option">--target</span></samp> +options that you use for configuring GCC, then build and install +them. They install their executables automatically into the proper +directory. Alas, they do not support all the targets that GCC +supports. + + <p>If you are not building a C library in the same source tree as GCC, +you should also provide the target libraries and headers before +configuring GCC, specifying the directories with +<samp><span class="option">--with-sysroot</span></samp> or <samp><span class="option">--with-headers</span></samp> and +<samp><span class="option">--with-libs</span></samp>. Many targets also require “start files” such +as <samp><span class="file">crt0.o</span></samp> and +<samp><span class="file">crtn.o</span></samp> which are linked into each executable. There may be several +alternatives for <samp><span class="file">crt0.o</span></samp>, for use with profiling or other +compilation options. Check your target's definition of +<code>STARTFILE_SPEC</code> to find out what start files it uses. + +<h3 class="section"><a name="TOC2"></a>0.3 Building in parallel</h3> + +<p>GNU Make 3.79 and above, which is necessary to build GCC, support +building in parallel. To activate this, you can use ‘<samp><span class="samp">make -j 2</span></samp>’ +instead of ‘<samp><span class="samp">make</span></samp>’. 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>0.4 Building the Ada compiler</h3> + +<p>In order to build GNAT, the Ada compiler, you need a working GNAT +compiler (GNAT version 3.14 or later, or GCC version 3.1 or later). +This includes GNAT tools such as <samp><span class="command">gnatmake</span></samp> and +<samp><span class="command">gnatlink</span></samp>, since the Ada front end is written in Ada and +uses some GNAT-specific extensions. + + <p>In order to build a cross compiler, it is suggested to install +the new compiler as native first, and then use it to build the cross +compiler. + + <p><samp><span class="command">configure</span></samp> 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 <samp><span class="option">--enable-languages</span></samp> is +used to disable building the Ada front end. + + <p><samp><span class="env">ADA_INCLUDE_PATH</span></samp> and <samp><span class="env">ADA_OBJECT_PATH</span></samp> environment variables +must not be set when building the Ada compiler, the Ada tools, or the +Ada runtime libraries. You can check that your build environment is clean +by verifying that ‘<samp><span class="samp">gnatls -v</span></samp>’ lists only one explicit path in each +section. + +<h3 class="section"><a name="TOC4"></a>0.5 Building with profile feedback</h3> + +<p>It is possible to use profile feedback to optimize the compiler itself. This +should result in a faster compiler binary. Experiments done on x86 using gcc +3.3 showed approximately 7 percent speedup on compiling C programs. To +bootstrap the compiler with profile feedback, use <code>make profiledbootstrap</code>. + + <p>When ‘<samp><span class="samp">make profiledbootstrap</span></samp>’ is run, it will first build a <code>stage1</code> +compiler. This compiler is used to build a <code>stageprofile</code> compiler +instrumented to collect execution counts of instruction and branch +probabilities. Then runtime libraries are compiled with profile collected. +Finally a <code>stagefeedback</code> compiler is built using the information collected. + + <p>Unlike standard bootstrap, several additional restrictions apply. The +compiler used to build <code>stage1</code> needs to support a 64-bit integral type. +It is recommended to only use GCC for this. Also parallel make is currently +not supported since collisions in profile collecting may occur. + + <p><hr /> +<p><a href="./index.html">Return to the GCC Installation page</a> + +<!-- ***Testing***************************************************************** --> +<!-- ***Final install*********************************************************** --> +<!-- ***Binaries**************************************************************** --> +<!-- ***Specific**************************************************************** --> +<!-- ***Old documentation****************************************************** --> +<!-- ***GFDL******************************************************************** --> +<!-- *************************************************************************** --> +<!-- Part 6 The End of the Document --> +</body></html> + |