[llvm-commits] CVS: llvm/www/docs/GettingStarted.html
John Criswell
criswell at cs.uiuc.edu
Thu Jul 3 11:02:01 PDT 2003
Changes in directory llvm/www/docs:
GettingStarted.html updated: 1.18 -> 1.19
---
Log message:
Performed a major update for the pre-release.
Attempted to better structure and order the document.
Added more information about autoconf, the build system, and how to build LLVM.
Added directions on how to build the C front end.
Added a section on common problems and their solutions.
---
Diffs of the changes:
Index: llvm/www/docs/GettingStarted.html
diff -u llvm/www/docs/GettingStarted.html:1.18 llvm/www/docs/GettingStarted.html:1.19
--- llvm/www/docs/GettingStarted.html:1.18 Tue Jul 1 16:55:57 2003
+++ llvm/www/docs/GettingStarted.html Thu Jul 3 11:01:38 2003
@@ -18,26 +18,27 @@
<ul>
<li><a href="#overview">Overview</a>
- <li><a href="#starting">Getting started with LLVM</a>
- <ol>
+ <ol>
<li><a href="#requirements">Requirements</a>
<ol>
<li><a href="#hardware">Hardware</a>
<li><a href="#software">Software</a>
</ol>
+ </ol>
+ <li><a href="#starting">Getting started with LLVM</a>
+ <ol>
<li><a href="#quickstart">Getting started quickly (a summary)</a>
- <li><a href="#checkout">Checkout LLVM from CVS</a>
<li><a href="#terminology">Terminology and Notation</tt></a>
- <li><a href="#objfiles">The location for object files</tt></a>
- <li><a href="#config">Local Configuration Options</tt></a>
<li><a href="#environment">Setting up your environment</a>
- <li><a href="#compile">Compiling the source code</a>
+ <li><a href="#checkout">Checkout LLVM from CVS</a>
+ <li><a href="#config">Local LLVM Configuration</tt></a>
+ <li><a href="#compile">Compiling the LLVM Suite Source Code</a>
+ <li><a href="#build">Building the LLVM C Front End</a>
+ <li><a href="#objfiles">The location for object files</tt></a>
</ol>
<li><a href="#layout">Program layout</a>
<ol>
<li><a href="#cvsdir">CVS directories</a>
- <li><a href="#dd"><tt>Depend</tt>, <tt>Debug</tt>, &
- <tt>Release</tt> directories</a></li>
<li><a href="#include"><tt>llvm/include</tt></a>
<li><a href="#lib"><tt>llvm/lib</tt></a>
<li><a href="#test"><tt>llvm/test</tt></a>
@@ -54,28 +55,29 @@
</center>
<!--=====================================================================-->
- <p>The <a href"starting">next section</a> of this guide is meant to get
- you up and running with LLVM and to give you some basic information about
- the LLVM environment. The <a href"#quickstart">first subsection</a> gives
- a short summary for those who are already familiar with the system and
- want to get started as quickly as possible.
-
- <p>The later sections of this guide describe the <a
- href="#layout">general layout</a> of the the LLVM source-tree, a <a
- href="#tutorial">simple example</a> using the LLVM tool chain, and <a
- href="#links">links</a> to find more information about LLVM or to get
- help via e-mail.
+ Welcome to LLVM! In order to get started, you first need to know some
+ basic information.
- <!--=====================================================================-->
- <center>
- <h2><a name="starting"><b>Getting Started</b></a></h2>
- </center>
- <!--=====================================================================-->
+ <p>
+ First, LLVM comes in two pieces. The first piece is the LLVM suite. This
+ contains all of the tools, libraries, and header files needed to use the
+ low level virtual machine. It also contains a test suite that can be used
+ to test the LLVM tools and the GCC front end.
+ <p>
+ The second piece is the GCC front end. This component provides a version
+ of GCC that compiles C code into LLVM bytecode. Currently, the C front end
+ is a modified version of GCC 3.4 (we track the GCC 3.4 development).
+ Once compiled into LLVM bytecode, a program can be manipulated with the
+ LLVM tools.
<!--=====================================================================-->
<h3><a name="requirements"><b>Requirements</b></a></h3>
<!--=====================================================================-->
+ Before you begin to use the LLVM system, review the requirements given
+ below. This may save you some trouble by knowing ahead of time what
+ hardware and software you will need.
+
<!--=====================================================================-->
<h4><a name="hardware"><b>Hardware</b></a></h4>
<!--=====================================================================-->
@@ -89,7 +91,7 @@
<li>Object code: 670 MB
</ul>
</ul>
- <li> Solaris on Sparc
+ <li> Solaris on SparcV9 (Ultrasparc)
<ul>
<li> Approximately 1.03 GB of Free Disk Space
<ul>
@@ -99,8 +101,12 @@
</ul>
</ul>
- LLVM may compile on other platforms. While the LLVM utilities should work,
- they will only generate Sparc or x86 machine code.
+ LLVM <i>may</i> compile on other platforms. The LLVM utilities should work
+ on other platforms, so it should be possible to generate and produce LLVM
+ bytecode on unsupported platforms (although bytecode generated on one
+ platform may not work on another platform). However, the code generators
+ and Just In Time Compilers (JIT's) only generate SparcV9 or x86 machine
+ code.
<!--=====================================================================-->
<h4><a name="software"><b>Software</b></a></h4>
@@ -109,30 +115,33 @@
Compiling LLVM requires that you have several different software packages
installed:
- <ul>
- <li> GCC
- <p>
+ <dl compact>
+ <dt> GCC
+ <dd>
The GNU Compiler Collection must be installed with C and C++ language
- support. GCC 3.x is supported, although some effort has been made to
- support GCC 2.96.
- </p>
+ support. GCC 3.2.x works, and GCC 3.x is generally supported.
<p>
Note that we currently do not support any other C++ compiler.
</p>
- <li> GNU Make
- <p>
+ <dt> GNU Make
+ <dd>
The LLVM build system relies upon GNU Make extensions. Therefore, you
will need GNU Make (sometimes known as gmake) to build LLVM.
- </p>
-
- <li> Flex and Bison
<p>
+
+ <dt> Flex and Bison
+ <dd>
The LLVM source code is built using flex and bison. You will not be
able to configure and compile LLVM without them.
- </p>
- </ul>
+ <p>
+
+ <dt> GNU M4
+ <dd>
+ If you are installing Bison on your machine for the first time, you
+ will need GNU M4 (version 1.4 or higher).
+ </dl>
<p>
There are some additional tools that you may want to have when working with
@@ -140,39 +149,70 @@
</p>
<ul>
- <li> GNU Autoconf and GNU M4
+ <li>GNU Autoconf
+ <li>GNU M4
<p>
- If you want to make changes to the autoconf scripts which configure LLVM
- for compilation, you will need GNU autoconf, and consequently, GNU M4.
- LLVM was built with autoconf 2.53, so that release and any later
- release should work.
+ If you want to make changes to the configure scripts, you will need
+ GNU autoconf (2.53 or higher), and consequently, GNU M4 (version 1.4
+ or higher).
</p>
</ul>
+
+ <p>The <a href="starting">next section</a> of this guide is meant to get
+ you up and running with LLVM and to give you some basic information about
+ the LLVM environment. The <a href"#quickstart">first subsection</a> gives
+ a short summary for those who are already familiar with the system and
+ want to get started as quickly as possible.
+
+ <p>The later sections of this guide describe the <a
+ href="#layout">general layout</a> of the the LLVM source-tree, a <a
+ href="#tutorial">simple example</a> using the LLVM tool chain, and <a
+ href="#links">links</a> to find more information about LLVM or to get
+ help via e-mail.
+
+ <!--=====================================================================-->
+ <center>
+ <h2><a name="starting"><b>Getting Started</b></a></h2>
+ </center>
+ <!--=====================================================================-->
+
<!--=====================================================================-->
<h3><a name="quickstart"><b>Getting Started Quickly (A Summary)</b></a></h3>
<!--=====================================================================-->
Here's the short story for getting up and running quickly with LLVM:
<ol>
- <li>Find the path to the CVS repository containing LLVM (we'll call this <i>CVSROOTDIR</i>).
- <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
- <li><tt>cvs -d <i>CVSROOTDIR</i> checkout llvm</tt>
- <li><tt>cd llvm</tt>
- <li>Run <tt>configure</tt> to configure the Makefiles and header files.
- Useful options include:
- <ul>
- <li><tt>--with-objroot=<i>directory</i></tt>
- <br>
- Specifiy where object files should be placed during the build.
-
- <li><tt>--with-llvmgccdir=<i>directory</i></tt>
- <br>
- Specifiy where the LLVM C frontend has been installed.
- </ul>
- <li>Set your LLVM_LIB_SEARCH_PATH environment variable.
- <li><tt>gmake -k |& tee gnumake.out
- # this is csh or tcsh syntax</tt>
+ <li>Build the LLVM suite
+ <ol>
+ <li>Find the path to the CVS repository containing LLVM (we'll call this <i>CVSROOTDIR</i>).
+ <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
+ <li><tt>cvs -d <i>CVSROOTDIR</i> checkout llvm</tt>
+ <li><tt>cd llvm</tt>
+ <li>Run <tt>configure</tt> to configure the Makefiles and header files.
+ Useful options include:
+ <ul>
+ <li><tt>--with-objroot=<i>directory</i></tt>
+ <br>
+ Specify where object files should be placed during the build.
+
+ <li><tt>--with-llvmgccdir=<i>directory</i></tt>
+ <br>
+ Specify where the LLVM C frontend is going to be installed.
+ </ul>
+ <li>Set your LLVM_LIB_SEARCH_PATH environment variable.
+ <li><tt>gmake -k |& tee gnumake.out
+ # this is csh or tcsh syntax</tt>
+ </ol>
+ <p>
+ <li>Build the LLVM C Front End
+ <ol>
+ <li>Create a directory for the object files to live.
+ <li><tt>cd <i>object file directory</i></tt>
+ <li>Run <tt><i>Pathname-to-where-the-source-code-lives</i>/configure --prefix=<i>LLVMGCCDIR</i></tt> to configure GCC.
+ <li><tt>make bootstrap</tt>
+ <li><tt>make install</tt>
+ </ol>
</ol>
<p>See <a href="#environment">Setting up your environment</a> on tips to
@@ -191,17 +231,93 @@
of this document below</i>. In any of the examples below, simply replace
each of these names with the appropriate pathname on your local system.
All these paths are absolute:</p>
- <ul>
- </ul>
+ <dl compact>
+ <dt>CVSROOTDIR
+ <dd>
+ This is the path for the CVS repository containing the LLVM source
+ code. Ask the person responsible for your local LLVM installation to
+ give you this path.
+ <p>
+
+ <dt>OBJ_ROOT
+ <dd>
+ This is the top level directory for where the LLVM suite object files
+ will be placed during the build.
+ <p>
+
+ <dt>LLVMGCCDIR
+ <dd>
+ This is the pathname to the location where the LLVM C Front End will
+ be installed. Note that the C front end does not need to be installed
+ during the LLVM suite build; you will just need to know where it will
+ go for configuring the build system and running the test suite later.
+ <p>
+
+ <dt>GCCSRC
+ <dd>
+ This is the pathname of the directory where the LLVM C front end source
+ code can be found.
+ <p>
+
+ <dt>GCCOBJ
+ <dd>
+ This is the pathname of the directory where the LLVM C front end object
+ code will be placed during the build. It can be safely removed once
+ the build is complete.
+ </dl>
<!------------------------------------------------------------------------->
- <h3><a name="checkout">Checkout LLVM from CVS</a></h3>
+ <h3><a name="environment">Setting up your environment</a></h3>
<!------------------------------------------------------------------------->
- <p>Before checking out the source code, you will need to know the path to
- the CVS repository containing the LLVM source code (we'll call this
- <i>CVSROOTDIR</i> below). Ask the person responsible for your local LLVM
- installation to give you this path.
+ <p>
+ In order to compile and use LLVM, you will need to set some environment
+ variables. There are also some shell aliases which you may find useful.
+ You can set these on the command line, or better yet, set them in your
+ <tt>.cshrc</tt> or <tt>.profile</tt>.
+
+ <dl compact>
+ <dt><tt>LLVM_LIB_SEARCH_PATH</tt>=<tt><i>LLVMGCCDIR</i>/llvm-gcc/bytecode-libs</tt>
+ <dd>
+ This environment variable helps the LLVM C front end find bytecode
+ libraries that it will need for compilation.
+ <p>
+
+ <dt><tt>PATH</tt>=<tt>${PATH}:<i>OBJ_ROOT</i>/llvm/tools/Debug</tt>
+ <dd>
+ Adding this directory to the end of your path will allow the
+ compilation of the C front end to find the LLVM tools. The LLVM tools
+ are needed for the C front end compile.
+ <p>
+
+ <dt><tt>CC</tt>=<i>Pathname to your GCC compiler</i>
+ <dd>
+ The GCC compiler that you want to use must be the first C compiler in
+ your <tt>PATH</tt>. Otherwise, set this variable so that
+ <tt>configure</tt> will use the GCC compiler that you want to use.
+ <p>
+
+ <dt><tt>CXX</tt>=<i>Pathname to your GCC C++ compiler</i>
+ <dd>
+ The GCC compiler that you want to use must be the first C++ compiler in
+ your <tt>PATH</tt>. Otherwise, set this variable so that
+ <tt>configure</tt> will use the GCC compiler that you want to use.
+ <p>
+
+ <dt><tt>CVSROOT</tt>=<i>CVSROOT</i>
+ <dd>
+ This environment variable tells CVS where to find the CVS repository.
+ <p>
+
+ <dt>alias llvmgcc <i>LLVMGCCDIR</i><tt>/bin/llvm-gcc</tt>
+ <dd>
+ This alias allows you to use the LLVM C front end without putting it in
+ your <tt>PATH</tt> or typing in its complete pathname.
+ </dl>
+
+ <!------------------------------------------------------------------------->
+ <h3><a name="checkout">Checkout LLVM from CVS</a></h3>
+ <!------------------------------------------------------------------------->
<p>To get a fresh copy of the entire source code, all you
need to do is check it out from CVS as follows:
@@ -214,13 +330,19 @@
directory and fully populate it with the LLVM source code, Makefiles,
test directories, and local copies of documentation files.</p>
+ <p>
+ Note that the C front end is not included in the CVS repository. You
+ should have either downloaded the source, or better yet, downloaded the
+ binary distribution for your platform.
+ </p>
+
<!------------------------------------------------------------------------->
- <h3><a name="config">Local Configuration Options</a></h3>
+ <h3><a name="config">Local LLVM Configuration</a></h3>
<!------------------------------------------------------------------------->
- <p>Once checked out from the CVS repository, options and pathnames specific
- to an installation of LLVM can be set via the <tt>configure</tt> script.
- This script sets variables in <tt>llvm/Makefile.config</tt> and
+ <p>Once checked out from the CVS repository, the LLVM suite source code
+ must be configured via the <tt>configure</tt> script. This script sets
+ variables in <tt>llvm/Makefile.config</tt> and
<tt>llvm/include/Config/config.h</tt>.
<p>
@@ -229,102 +351,250 @@
</p>
<ul>
- <p><li><i>CXX</i> = Pathname of the C++ compiler to use.
- <p><li><i>CC</i> = Pathname of the C compiler to use.
+ <p><li><i>CXX</i> = Pathname of the C++ compiler to use.
+ <p><li><i>CC</i> = Pathname of the C compiler to use.
</ul>
The following options can be used to set or enable LLVM specific options:
- <ul>
- <p><li><i>--with-objroot=LLVM_OBJ_ROOT</i> =
+ <dl compact>
+ <dt><i>--with-objroot=OBJ_ROOT</i>
+ <dd>
Path to the directory where
object files, libraries, and executables should be placed.
+ If this is set to <tt>.</tt>, then the object files will be placed
+ within the source code tree. If left unspecified, the default value is
+ <tt>.</tt>.
(See the Section on <a href=#objfiles>
The location for LLVM object files</a>
for more information.)
- <p><li><i>--with-llvmgccdir=LLVMGCCDIR</i> =
- Path to the location of the LLVM front-end
- binaries and associated libraries.
- <p><li><i>--enable-optimized</i> =
+ <p>
+ <dt><i>--with-llvmgccdir=LLVMGCCDIR</i>
+ <dd>
+ Path to the location where the LLVM C front end binaries and
+ associated libraries will be installed.
+ <p>
+ <dt><i>--enable-optimized</i>
+ <dd>
Enables optimized compilation (debugging symbols are removed and GCC
- optimization flags are enabled).
- <p><li><i>--enable-jit</i> =
+ optimization flags are enabled). The default is to use an unoptimized
+ build (also known as a debug build).
+ <p>
+ <dt><i>--enable-jit</i>
+ <dd>
Compile the Just In Time (JIT) functionality. This is not available
- on all platforms.
- </ul>
+ on all platforms. The default is dependent on platform, so it is best
+ to explicitly enable it if you want it.
+ </dl>
In addition to running <tt>configure</tt>, you must set the
<tt>LLVM_LIB_SEARCH_PATH</tt> environment variable in your startup scripts.
This environment variable is used to locate "system" libraries like
"<tt>-lc</tt>" and "<tt>-lm</tt>" when linking. This variable should be set
to the absolute path for the bytecode-libs subdirectory of the C front-end
- install. For example, one might set <tt>LLVM_LIB_SEARCH_PATH</tt> to
+ install, or LLVMGCCDIR/llvm-gcc/bytecode-libs. For example, one might
+ set <tt>LLVM_LIB_SEARCH_PATH</tt> to
<tt>/home/vadve/lattner/local/x86/llvm-gcc/bytecode-libs</tt> for the X86
version of the C front-end on our research machines.<p>
<!------------------------------------------------------------------------->
+ <h3><a name="compile">Compiling the LLVM Suite Source Code</a></h3>
+ <!------------------------------------------------------------------------->
+
+ Once you have configured LLVM, you can build it. There are three types of
+ builds:
+
+ <dl compact>
+ <dt>Debug Builds
+ <dd>
+ These builds are the default. They compile the tools and libraries
+ with debugging information.
+ <p>
+
+ <dt>Release (Optimized) Builds
+ <dd>
+ These builds are enabled with the <tt>--enable-optimized</tt> option to
+ <tt>configure</tt>. They compile the tools and libraries with GCC
+ optimizer flags on and strip debugging information from the libraries
+ and executables it generates.
+ <p>
+
+ <dt>Profile Builds
+ <dd>
+ These builds are for use with profiling. They compile profiling
+ information into the code for use with programs like <tt>gprof</tt>.
+ Profile builds must be started by setting variables on the
+ <tt>make</tt> command line.
+ </dl>
+
+ Once you have LLVM configured, you can build it by entering the top level
+ <tt>llvm</tt> directory and issuing the following command:
+ <p>
+ <tt>make</tt>
+
+ <p>
+ If you have multiple processors in your machine, you may wish to use some
+ of the parallel build options provided by GNU Make. For example, you could
+ use the command:
+ </p>
+
+ <p>
+ <tt>make -j2</tt>
+
+ <p>
+ There are several other targets which are useful when working with the LLVM
+ source code:
+
+ <dl compact>
+ <dt><tt>make clean</tt>
+ <dd>
+ Removes all files generated by the build. This includes object files,
+ generated C/C++ files, libraries, and executables.
+ <p>
+
+ <dt><tt>make distclean</tt>
+ <dd>
+ Removes everything that <tt>make clean</tt> does, but also removes
+ files generated by <tt>configure</tt>. It attempts to return the
+ source tree to the original state in which it was shipped.
+ <p>
+ </dl>
+
+ It is also possible to override default values from <tt>configure</tt> by
+ declaring variables on the command line. The following are some examples:
+
+ <dl compact>
+ <dt><tt>make ENABLE_OPTIMIZED=1</tt>
+ <dd>
+ Perform a Release (Optimized) build.
+ <p>
+
+ <dt><tt>make ENABLE_PROFILING=1</tt>
+ <dd>
+ Perform a Profiling build.
+ <p>
+
+ <dt><tt>make VERBOSE=1</tt>
+ <dd>
+ Print what <tt>make</tt> is doing on standard output.
+ <p>
+ </dl>
+
+ Every directory in the LLVM source tree includes a <tt>Makefile</tt> to
+ build it and any subdirectories that it contains. Entering any directory
+ inside the LLVM source tree and typing <tt>make</tt> should rebuild
+ anything in or below that directory that is out of date.
+
+ <!------------------------------------------------------------------------->
+ <h3><a name="build">Building the LLVM C Front End</a></h3>
+ <!------------------------------------------------------------------------->
+
+ <b>
+ <p>
+ This step is optional if you have the C front end binary distrubtion for
+ your platform.
+ </p>
+ </b>
+
+ Now that you have the LLVM Suite built, you can build the C front end. For
+ those of you that have built GCC before, the process is very similar.
+ <p>
+ Be forewarned, though: the build system for the C front end is not as
+ polished as the rest of the LLVM code, so there will be many warnings and
+ errors that you will need to ignore for now:
+
+ <ol>
+ <li>Ensure that <tt><i>OBJ_ROOT</i>/llvm/tools/Debug</tt> is at the
+ <i>end</i> of your <tt>PATH</tt> environment variable.
+
+ <li><tt>cd <i>GCCOBJ</i></tt>
+
+ <li>Configure the source code:
+ <ul>
+ <li>On Linux/x86, use
+ <ul>
+ <li><tt><i>GCCSRC</i>/configure --prefix=<i>LLVMGCCDIR</i>
+ --enable-languages=c</tt>
+ </ul>
+
+ <li>On Solaris/Sparc, use
+ <ul>
+ <li><tt><i>GCCSRC</i>/configure --prefix=<i>LLVMGCCDIR</i>
+ --enable-languages=c --target=sparcv9-sun-solaris2</tt>
+ </ul>
+ </ul>
+
+ <li><tt>make bootstrap</tt>
+
+ <li>The build will eventually fail. Don't worry; chances are good that
+ everything that needed to build is built.
+
+ <li><tt>make install</tt>
+ </ol>
+
+ At this point, you should have a working copy of the LLVM C front end
+ installed in <i>LLVMGCCDIR</i>.
+
+ <!------------------------------------------------------------------------->
<h3><a name="objfiles">The location for LLVM object files</a></h3>
<!------------------------------------------------------------------------->
- <p>The LLVM make system sends most output files generated during the build
- into the directory defined by the variable OBJ_ROOT in
- <tt>llvm/Makefile.config</tt>. This can be either just your normal LLVM
+ <p>The LLVM build system sends most output files generated during the build
+ into the directory defined by the variable <i>OBJ_ROOT</i> in
+ <tt>llvm/Makefile.config</tt>, which is set by the <i>--with-objroot</i>
+ option in <tt>configure</tt>. This can be either just your normal LLVM
source tree or some other directory writable by you. You may wish to put
object files on a different filesystem either to keep them from being backed
up or to speed up local builds.
- <p>If you wish to place output files into a separate directory, use the
- <tt>--with-objroot=<i>directory</i></tt> option of <tt>configure</tt> to
- set the top level directory of where the object files will go. Otherwise,
- leave this option unspecified, and <tt>configure</tt> will place files
- within the LLVM source tree.
+ <p>
+ If <i>OBJ_ROOT</i> is specified, then the build system will create a
+ directory tree underneath it that resembles the source code's pathname
+ relative to your home directory.
+ </p>
- <!------------------------------------------------------------------------->
- <h3><a name="environment">Setting up your environment</a></h3>
- <!------------------------------------------------------------------------->
+ <p>
+ For example, suppose that <i>OBJ_ROOT</i> is set to <tt>/tmp</tt> and the
+ LLVM suite source code is located in <tt>/usr/home/joe/src/llvm</tt>, where
+ <tt>/usr/home/joe</tt> is the home directory of a user named Joe. Then,
+ the object files will be placed in <tt>/tmp/src/llvm</tt>.
+ </p>
- <i>NOTE: This step is optional but will set up your environment so you
- can use the compiled LLVM tools with as little hassle as
- possible.</i>)
-
- <p>Add the following lines to your <tt>.cshrc</tt> (or the corresponding
- lines to your <tt>.profile</tt> if you use a bourne shell derivative).
-
- <pre>
- # Make the C front end easy to use...
- alias llvmgcc <i>LLVMGCCDIR</i><tt>/bin/llvm-gcc</tt>
-
- # Make the LLVM tools easy to use...
- setenv PATH <i>OBJ_ROOT</i>/llvm/tools/Debug:${PATH}
- </pre>
- The <tt>llvmgcc</tt> alias is useful because the C compiler is not
- included in the CVS tree you just checked out.
-
- <p>The other <a href="#tools">LLVM tools</a> are part of the LLVM
- source base and built when compiling LLVM. They will be built into the
- <tt><i>OBJ_ROOT</i>/tools/Debug</tt> directory.</p>
-
- <!------------------------------------------------------------------------->
- <h3><a name="compile">Compiling the source code</a></h3>
- <!------------------------------------------------------------------------->
-
- <p>Every directory in the LLVM source tree includes a <tt>Makefile</tt> to
- build it and any subdirectories that it contains. These makefiles require
- that you use GNU Make (sometimes called <tt>gmake</tt>) instead of
- <tt>make</tt> to
- build them, but can
- otherwise be used freely. To build the entire LLVM system, just enter the
- top level <tt>llvm</tt> directory and type <tt>gmake</tt>. A few minutes
- later you will hopefully have a freshly compiled toolchain waiting for you
- in <tt><i>OBJ_ROOT</i>/llvm/tools/Debug</tt>. If you want to look at the
- libraries that
- were compiled, look in <tt><i>OBJ_ROOT</i>/llvm/lib/Debug</tt>.</p>
-
- If you get an error about a <tt>/localhome</tt> directory, follow the
- instructions in the section about <a href="#environment">Setting Up Your
- Environment.</a>
+ <p>
+ The LLVM build will place files underneath <i>OBJ_ROOT</i> in directories
+ named after the build type:
+ </p>
+ <dl compact>
+ <dt>Debug Builds
+ <dd>
+ <dl compact>
+ <dt>Tools
+ <dd><tt><i>OBJ_ROOT</i>/llvm/tools/Debug</tt>
+ <dt>Libraries
+ <dd><tt><i>OBJ_ROOT</i>/llvm/lib/Debug</tt>
+ </dl>
+ <p>
+ <dt>Release Builds
+ <dd>
+ <dl compact>
+ <dt>Tools
+ <dd><tt><i>OBJ_ROOT</i>/llvm/tools/Release</tt>
+ <dt>Libraries
+ <dd><tt><i>OBJ_ROOT</i>/llvm/lib/Release</tt>
+ </dl>
+ <p>
+
+ <dt>Profile Builds
+ <dd>
+ <dl compact>
+ <dt>Tools
+ <dd><tt><i>OBJ_ROOT</i>/llvm/tools/Profile</tt>
+ <dt>Libraries
+ <dd><tt><i>OBJ_ROOT</i>/llvm/lib/Profile</tt>
+ </dl>
+ </dl>
<!--=====================================================================-->
<center>
@@ -332,7 +602,7 @@
</center>
<!--=====================================================================-->
- <p>One useful source of infomation about the LLVM sourcebase is the LLVM <a
+ <p>One useful source of information about the LLVM source base is the LLVM <a
href="http://www.doxygen.org">doxygen</a> documentation, available at <tt><a
href="http://llvm.cs.uiuc.edu/doxygen/">http://llvm.cs.uiuc.edu/doxygen/</a></tt>. The
following is a brief introduction to code layout:</p>
@@ -347,25 +617,6 @@
<!------------------------------------------------------------------------->
- <h3><a name="ddr"><tt>Depend</tt>, <tt>Debug</tt>, & <tt>Release</tt>
- directories</a></h3>
- <!------------------------------------------------------------------------->
-
- If you are building with the "<tt>OBJ_ROOT=.</tt>" option enabled in the
- <tt>Makefile.config</tt> file (i.e. you did not specify
- <tt>--with-objroot</tt> when you ran <tt>configure</tt>), most source
- directories will contain two
- directories, <tt>Depend</tt> and <tt>Debug</tt>. The <tt>Depend</tt>
- directory contains automatically generated dependance files which are used
- during compilation to make sure that source files get rebuilt if a header
- file they use is modified. The <tt>Debug</tt> directory holds the object
- files, library files, and executables that are used for building a debug
- enabled build. The <tt>Release</tt> directory is created to hold the same
- files when the <tt>ENABLE_OPTIMIZED=1</tt> flag is passed to <tt>gmake</tt>,
- causing an optimized build to be performed.<p>
-
-
- <!------------------------------------------------------------------------->
<h3><a name="include"><tt>llvm/include</tt></a></h3>
<!------------------------------------------------------------------------->
@@ -379,7 +630,7 @@
<tt>Reoptimizer</tt>, <tt>Target</tt>, <tt>Transforms</tt>, etc...
<li><tt>llvm/include/Support</tt> - This directory contains generic
- support libraries that are independant of LLVM, but are used by LLVM.
+ support libraries that are independent of LLVM, but are used by LLVM.
For example, some C++ STL utilities and a Command Line option processing
library.
@@ -466,7 +717,7 @@
<dt><tt><b>lli</b></tt><dd> <tt>lli</tt> is the LLVM interpreter, which
can directly execute LLVM bytecode (although very slowly...). In addition
- to a simple intepreter, <tt>lli</tt> is also has debugger and tracing
+ to a simple interpreter, <tt>lli</tt> is also has debugger and tracing
modes (entered by specifying <tt>-debug</tt> or <tt>-trace</tt> on the
command line, respectively).<p>
@@ -491,7 +742,7 @@
disassembled or manipulated just like any other bytecode file). The
command line interface to <tt>gccas</tt> is designed to be as close as
possible to the <b>system</b> '<tt>as</tt>' utility so that the gcc
- frontend itself did not have to be modified to interface to a "wierd"
+ frontend itself did not have to be modified to interface to a "weird"
assembler.<p>
<dt><tt><b>gccld</b></tt><dd> <tt>gccld</tt> links together several LLVM
@@ -571,6 +822,58 @@
<!--=====================================================================-->
+ <h2><a name="help">Common Problems</a></h2>
+ <!--=====================================================================-->
+
+ Below are common problems and their remedies:
+
+ <dl compact>
+ <dt><b>When I run configure, it finds the wrong C compiler.</b>
+ <dd>
+ The <tt>configure</tt> script attempts to locate first <tt>gcc</tt> and
+ then <tt>cc</tt>, unless it finds compiler paths set in <tt>CC</tt> and
+ <tt>CXX</tt> for the C and C++ compiler, respectively.
+
+ If <tt>configure</tt> finds the wrong compiler, either adjust your
+ <tt>PATH</tt> environment variable or set <tt>CC</tt> and <tt>CXX</tt>
+ explicitly.
+ <p>
+
+ <dt><b>I compile the code, and I get some error about /localhome</b>.
+ <dd>
+ There are several possible causes for this. The first is that you
+ didn't set a pathname properly when using <tt>configure</tt>, and it
+ defaulted to a pathname that we use on our research machines.
+ <p>
+ Another possibility is that we hardcoded a path in our Makefiles. If
+ you see this, please email the LLVM bug mailing list with the name of
+ the offending Makefile and a description of what is wrong with it.
+
+ <dt><b>The <tt>configure</tt> script finds the right C compiler, but it
+ uses the LLVM linker from a previous build. What do I do?</b>
+ <dd>
+ The <tt>configure</tt> script uses the <tt>PATH</tt> to find
+ executables, so if it's grabbing the wrong linker/assembler/etc, there
+ are two ways to fix it:
+ <ol>
+ <li>Adjust your <tt>PATH</tt> environment variable so that the
+ correct program appears first in the <tt>PATH</tt>. This may work,
+ but may not be convenient when you want them <i>first</i> in your
+ path for other work.
+ <p>
+
+ <li>Run <tt>configure</tt> with an alternative <tt>PATH</tt> that
+ is correct. In a Borne compatible shell, the syntax would be:
+ <p>
+ <tt>PATH=<the path without the bad program> ./configure ...</tt>
+ <p>
+ This is still somewhat inconvenient, but it allows
+ <tt>configure</tt> to do its work without having to adjust your
+ <tt>PATH</tt> permanently.
+ </ol>
+ </dl>
+
+ <!--=====================================================================-->
<h2><a name="links">Links</a></h2>
<!--=====================================================================-->
@@ -583,6 +886,7 @@
<ul>
<li><a href="http://llvm.cs.uiuc.edu/">LLVM homepage</a></li>
<li><a href="http://llvm.cs.uiuc.edu/doxygen/">LLVM doxygen tree</a></li>
+ <li><a href="http://llvm.cs.uiuc.edu/docs/Projects.html">Starting a Project that Uses LLVM</a></li>
</ul>
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