This document is intended to explain the process of building the -LLVM C/C++ front-end, based on GCC 3.4, from its source code. You -would have to do this, for example, if you are porting LLVM to a new -architecture or operating system.
-NOTE: This is currently a somewhat fragile, error-prone -process, and you should only try to do it if:
+This section describes how to aquire and build llvm-gcc4, which is based on +the GCC 4.0.1 front-end. This front-end supports C, C++, Objective-C, and +Objective-C++. Note that the instructions for building this front-end are +completely different (and much easier!) than those for building llvm-gcc3 in +the past.
We welcome patches to help make this process simpler.
-If you are building LLVM and the GCC front-end under Cygwin, please note that -the LLVM and GCC makefiles do not correctly handle spaces in paths. To deal -with this issue, make sure that your LLVM and GCC source and build trees are -located in a top-level directory (like /cygdrive/c/llvm and -/cygdrive/c/llvm-cfrontend), not in a directory that contains a space -(which includes your "home directory", because it lives under the "Documents -and Settings" directory). We welcome patches to fix this issue. -
-If you are building LLVM and the GCC front-end under AIX, do NOT use GNU -Binutils. They are not stable under AIX and may produce incorrect and/or -invalid code. Instead, use the system assembler and linker. -
--
Configure and build the LLVM libraries and tools using:
-- % cd llvm - % ./configure --prefix=/some/path/you/can/install/to [options...] - % gmake tools-only --
This will build all of the LLVM tools and libraries. The --prefix - option defaults to /usr/local (per configure standards) but unless you are a - system administrator, you probably won't be able to install LLVM there because - of permissions. Specify a path into which LLVM can be installed (e.g. - --prefix=/home/user/llvm).
-Add the directory containing the tools to your PATH.
-- % set path = ( `cd llvm/Debug/bin && pwd` $path ) -
Unpack the C/C++ front-end source into cfrontend/src.
Make "build" and "install" directories as siblings of the "src" tree.
-- % pwd - /usr/local/example/cfrontend/src - % cd .. - % mkdir build install - % set CFEINSTALL = `pwd`/install -
Configure, build, and install the GCC front-end:
- -
-Linux/x86:
-MacOS X/PowerPC (requires dlcompat library):
-AIX/PowerPC:
-
Retrieve the appropriate llvm-gcc4-x.y.source.tar.gz archive from the + llvm web site.
-- % cd build - % ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \ - --disable-shared --enable-languages=c,c++ - % gmake - % setenv LLVM_LIB_SEARCH_PATH `pwd`/gcc - % gmake all; gmake install -- -
Cygwin/x86:
- -- % cd build - % ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \ - --disable-shared --enable-languages=c,c++ --disable-c-mbchar - % gmake - % setenv LLVM_LIB_SEARCH_PATH `pwd`/gcc - % gmake all; gmake install -- -
Solaris/SPARC:
- --For Solaris/SPARC, LLVM only supports the SPARC V9 architecture. Therefore, -the configure command line should specify sparcv9, as shown below. Also, -note that Solaris has trouble with various wide (multibyte) character -functions from C as referenced from C++, so we typically configure with ---disable-c-mbchar (cf. Bug 206). -
+It is also possible to download the sources of the llvm-gcc4 front end + from a read-only mirror using subversion. To check out the code the + first time use:
+- % cd build - % ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \ - --disable-shared --enable-languages=c,c++ --host=sparcv9-sun-solaris2.8 \ - --disable-c-mbchar - % gmake - % setenv LLVM_LIB_SEARCH_PATH `pwd`/gcc - % gmake all; gmake install +svn co http://llvm.org/svn/llvm-project/llvm-gcc-4.0/trunk dst-directory+
Common Problem: You may get error messages regarding the fact - that LLVM does not support inline assembly. Here are two common - fixes:
- -Fix 1: If you have system header files that include
- inline assembly, you may have to modify them to remove the inline
- assembly and install the modified versions in
- $CFEINSTALL/lib/gcc/target-triplet/3.4-llvm/include.
src/libstdc++-v3/config/cpu/name-of-cpu/atomicity.h
- and apply a patch so that it does not use inline assembly.Porting to a new architecture: If you are porting the front-end - to a new architecture or compiling in a configuration that we have - not tried previously, there are probably several changes you will have to make - to the GCC target to get it to work correctly. These include:
- -
Go back into the LLVM source tree proper. Rerun configure, using
-the --with-llvmgccdir=$CFEINSTALL option to specify the path
-to the newly built GCC front-end.
If you edited header files during the C/C++ front-end build as
-described in "Fix 1" above, you must now copy those header files from
-$CFEINSTALL/target-triplet/sys-include to
-$CFEINSTALL/lib/gcc/target-triplet/3.4-llvm/include.
-(This should be the "include" directory in the same directory as the
-libgcc.a library, which you can find by running
-$CFEINSTALL/bin/gcc --print-libgcc-file-name.)
After that, the code can be be updated in the destination directory + using:
-Rebuild your CVS tree. This shouldn't cause the whole thing to be - rebuilt, but it should build the runtime libraries. After the tree is - built, install the runtime libraries into your GCC front-end build tree. - These are the commands you need.
-- % gmake - % mkdir $CFEINSTALL/lib - % gmake -C runtime install-bytecode - % setenv LLVM_LIB_SEARCH_PATH $CFEINSTALL/lib -
svn update+
Optionally, build a symbol table for the newly installed runtime -libraries. Although this step is optional, you are encouraged to do this as the -symbol tables will make a significant difference in your link times. Use -the llvm-ranlib tool to do this, as follows:
-- % cd $CFEINSTALL/lib - % llvm-ranlib libiberty.a - % llvm-ranlib libstdc++.a - % llvm-ranlib libsupc++.a - % cd $CFEINSTALL/lib/target-triplet/3.4-llvm - % llvm-ranlib libgcc.a - % llvm-ranlib libgcov.a -+
The mirror is brought up to date every evening.
Test the newly-installed C frontend by one or more of the -following means:
--The software also has the following additional copyrights: +More information is available in the FAQ.
- -- -Copyright (c) 2003, 2004 University of Illinois at Urbana-Champaign. -All rights reserved. - -Developed by: - - LLVM Team - - University of Illinois at Urbana-Champaign - - http://llvm.cs.uiuc.edu - -THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR -IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS -FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE -CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER -LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, -OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE -SOFTWARE. - -Copyright (c) 1994 -Hewlett-Packard Company - -Permission to use, copy, modify, distribute and sell this software -and its documentation for any purpose is hereby granted without fee, -provided that the above copyright notice appear in all copies and -that both that copyright notice and this permission notice appear -in supporting documentation. Hewlett-Packard Company makes no -representations about the suitability of this software for any -purpose. It is provided "as is" without express or implied warranty. - -Copyright (c) 1996, 1997, 1998, 1999 -Silicon Graphics Computer Systems, Inc. - -Permission to use, copy, modify, distribute and sell this software -and its documentation for any purpose is hereby granted without fee, -provided that the above copyright notice appear in all copies and -that both that copyright notice and this permission notice appear -in supporting documentation. Silicon Graphics makes no -representations about the suitability of this software for any -purpose. It is provided "as is" without express or implied warranty. -