This document is intended to explain the process of building the -LLVM C/C++ front-end from its source code. You have to do this, for example, if -you are porting LLVM to a new architecture or operating system, if you are -working from Top-Of-Tree CVS/SVN, or if there is no precompiled snapshot -available.
-NOTE: This is currently a somewhat fragile, error-prone -process, and you should only try to do it if:
+This document is intended to explain the process of building the LLVM C/C++ +front-end from its source code. You have to do this, for example, if you are +porting LLVM to a new architecture or operating system, if you are working from +Top-Of-Tree CVS/SVN, or if there is no precompiled snapshot available.
+ +NOTE: This is currently a somewhat fragile, error-prone process, and +you should only try to do it if:
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 +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. -
+(which includes your "home directory", because it lives under the "Documents and +Settings" directory). We welcome patches to fix this issue. +It has been found that the GCC 3.3.3 compiler provided with recent Cygwin versions is incapable of compiling the LLVM GCC front-end correctly. If your -Cygwin -installation includes GCC 3.3.3, we strongly recommend that you download -GCC 3.4.3, build it separately, and use it for compiling the LLVM GCC front-end. - This has been -shown to work correctly.
+Cygwin installation includes GCC 3.3.3, we strongly recommend that you +download GCC 3.4.3, build it separately, and use it for compiling the LLVM GCC +front-end. This has been shown to work correctly. +Some versions of Cygwin utilize an experimental version of GNU binutils that will cause the GNU ld linker to fail an assertion when linking components of the libstdc++. It is recommended that you replace the entire binutils package with version 2.15 such that "ld --version" responds with
+ +GNU ld version 2.15-not with:
not with:
+ +GNU ld version 2.15.91 20040725
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. -
+invalid code. Instead, use the system assembler and linker. +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 +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 than those for building llvm-gcc3. -
+completely different than those for building llvm-gcc3.Retrieve the appropriate llvm-gcc4-x.y.source.tar.gz archive from the llvm -web site.
-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: -
+Retrieve the appropriate llvm-gcc4-x.y.source.tar.gz archive from the + llvm web site.
-svn co svn://anonsvn.opensource.apple.com/svn/llvm/trunk -dst-directory +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:
-After that, the code can be be updated in the destination directory using; -
++svn co svn://anonsvn.opensource.apple.com/svn/llvm/trunk dst-directory ++
After that, the code can be be updated in the destination directory + using:
-The mirror is brought up to date every evening.
-svn update+
The mirror is brought up to date every evening.
+ +Configure and build the LLVM libraries and tools. There are two ways to -do this: either with objdir == srcdir or -objdir != srcdir. It is recommended -that srcdir be the same as objdir for your LLVM tree (but note -that you should always use srcdir != objdir for llvm-gcc):
-- % cd objdir - % srcdir/configure --prefix=/some/path/you/can/install/to [options...] - % gmake tools-only -
- % 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).
-Configure and build the LLVM libraries and tools. There are two ways to + do this: either with objdir == srcdir or + objdir != srcdir. It is recommended that + srcdir be the same as objdir for your + LLVM tree (but note that you should always use srcdir != + objdir for llvm-gcc):
-Add the directory containing the tools to your PATH.
+With objdir != srcdir:
+ +- % set path = ( `cd llvm/Debug/bin && pwd` $path ) -- -
Unpack the C/C++ front-end source into cfrontend/src, either by - untar'ing a cfrontend.source.tar.gz file or checking out CVS into this - directory.
Make "build" and "install" directories as siblings of the "src" tree:
-- % pwd - /usr/local/example/cfrontend/src - % cd .. - % mkdir build install - % set CFEINSTALL = `pwd`/install -
Configure, build, and install the GCC front-end:
- -
-Linux/x86:
-Linux/IA-64:
-MacOS X/PowerPC (requires dlcompat library):
-AIX/PowerPC:
-
- % cd build - % ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \ - --disable-shared --enable-languages=c,c++ --program-prefix=llvm- - % gmake all; gmake install +% cd objdir +% srcdir/configure --prefix=/some/path/you/can/install/to [options...] +% gmake tools-only+
With objdir == srcdir:
-Cygwin/x86:
- +- % cd build - % ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \ - --disable-shared --enable-languages=c,c++ --disable-c-mbchar \ - --program-prefix=llvm- - % gmake all; gmake install +% cd llvm +% ./configure --prefix=/some/path/you/can/install/to [options...] +% gmake tools-only+
Solaris/SPARC:
- --The GCC front-end can be configured for either SPARC V8 (32 bit) or SPARC V9 (64 -bit). This changes, among other things, the sizes of integer types and the -macros defined for conditional compilation. -
- --The SPARC V8 ABI support is more robust than the V9 ABI support and can generate -SPARC V9 code. It is highly recommended that you use the V8 ABI with LLVM, as -shown below. Also, -note that Solaris has trouble with various wide (multibyte) character -functions from C as referenced from C++, so we typically configure with ---disable-c-mbchar (cf. Bug 206). -
+This will build all of the LLVM tools and libraries. The + --prefix option defaults to /usr/local (per configure + standards) but unless you are a system administrator, you probably + won't be able to install LLVM there because of permissions. Specify a + path into which LLVM can be installed + (e.g. --prefix=/home/user/llvm).
Add the directory containing the tools to your PATH.
+- % cd build - % ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \ - --disable-shared --enable-languages=c,c++ --host=sparc-sun-solaris2.8 \ - --disable-c-mbchar --program-prefix=llvm- - % gmake all; gmake install + % set path = ( `cd llvm/Debug/bin && pwd` $path )- -
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:
- -
Put $CFEINSTALL/bin into your PATH environment -variable.
-Go back into the LLVM source tree proper. Rerun configure, using -the same options as the last time. This will cause the configuration to now find -the newly built llvm-gcc and llvm-g++ executables.
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:
+sh:- % gmake - % gmake -C runtime install-bytecode -
Optionally, build a symbol table for the newly installed runtime -libraries. Although this step is optional, you are strongly 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 $CFEINSTALL/lib/gcc/target-triplet/3.4-llvm - % llvm-ranlib libgcc.a - % llvm-ranlib libgcov.a + % export PATH=`cd llvm/Debug/bin && pwd`:$PATH+
Test the newly-installed C frontend by one or more of the -following means:
-Unpack the C/C++ front-end source into cfrontend/src, either by + untar'ing a cfrontend.source.tar.gz file or checking out CVS into this + directory.
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 ++sh: +
+ % pwd + /usr/local/example/cfrontend/src + % cd .. + % mkdir build install + % export CFEINSTALL=`pwd`/install ++
Configure, build, and install the GCC front-end:
+ +
+ Linux/x86:
+ Linux/IA-64:
+ MacOS X/PowerPC (requires dlcompat library):
+ AIX/PowerPC:
+
+% cd build +% ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \ + --disable-shared --enable-languages=c,c++ --program-prefix=llvm- +% gmake all; gmake install ++
Cygwin/x86:
+ ++% cd build +% ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \ + --disable-shared --enable-languages=c,c++ --disable-c-mbchar \ + --program-prefix=llvm- +% gmake all; gmake install ++
Solaris/SPARC:
+ +The GCC front-end can be configured for either SPARC V8 (32 bit) or + SPARC V9 (64 bit). This changes, among other things, the sizes of + integer types and the macros defined for conditional compilation.
+ +The SPARC V8 ABI support is more robust than the V9 ABI support and can + generate SPARC V9 code. It is highly recommended that you use the V8 + ABI with LLVM, 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).
+ ++% cd build +% ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \ + --disable-shared --enable-languages=c,c++ --host=sparc-sun-solaris2.8 \ + --disable-c-mbchar --program-prefix=llvm- +% gmake all; gmake install ++
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:
+ +Put $CFEINSTALL/bin into your PATH environment + variable.
+ ++ % setenv PATH $CFEINSTALL/bin:$PATH ++sh: +
+ % export PATH=$CFEINSTALL/bin:$PATH ++
Go back into the LLVM source tree proper. Rerun configure, using the + same options as the last time. This will cause the configuration to now + find the newly built llvm-gcc and llvm-g++ executables.
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 +% gmake -C runtime install-bytecode ++
Optionally, build a symbol table for the newly installed runtime + libraries. Although this step is optional, you are strongly 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/gcc/target-triplet/3.4-llvm +% llvm-ranlib libgcc.a +% llvm-ranlib libgcov.a ++
Test the newly-installed C frontend by one or more of the following + means:
+ +