| -Instructions - |
This document is intended to explain the process of building the LLVM -C/C++ front-end, based on GCC 3.4, from source.
- -NOTE: This is currently a somewhat fragile, error-prone -process, and you should only try to do it if (A) you really, really, -really can't use the binaries we distribute, and (B) you are a wicked -good GCC hacker.
- -We welcome patches to help make this process simpler.
- -Configure and build the LLVM libraries and tools using:
-- % cd llvm - % ./configure [options...] - % gmake tools-only --
The use of the non-default target "tools-only" means that the - LLVM tools and libraries will build, and the binaries will be - deposited in llvm/tools/Debug, but the runtime (bytecode) - libraries will not build.
- -Add the directory containing the tools to your PATH.
-- % set path = ( `cd llvm/tools/Debug && pwd` $path ) -- -
Unpack the C/C++ front-end source into cfrontend/src.
- -Edit src/configure. Change the first line (starting w/ #!) to - contain the correct full pathname of sh.
- -Make "build" and "install" directories as siblings of the "src" - tree.
-- % pwd - /usr/local/example/cfrontend/src - % cd .. - % mkdir build install - % set CFEINSTALL = `pwd`/install -- -
Configure, build and install the C front-end:
-- % cd build - % ../src/configure --prefix=$CFEINSTALL --disable-nls --disable-shared \ - --enable-languages=c,c++ - % gmake all-gcc - % setenv LLVM_LIB_SEARCH_PATH `pwd`/gcc - % gmake all; gmake install -- -
Common Problem 1: 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
- $CFEINSTALL/target-triplet/sys-include.
src/libstdc++-v3/config/cpu/name-of-cpu/atomicity.h
- and apply a patch so that it does not use inline assembly.
- Common Problem 2: FIXME: Chris should add a section about - common problems porting to a new architecture, including changes you - might have to make to the gcc/gcc/config/name-of-cpu - directory. For example (expand these):
- -Go back into the LLVM source tree proper. Edit Makefile.config
-to redefine LLVMGCCDIR to the full pathname of the
-$CFEINSTALL directory, which is the directory you just
-installed the C front-end into. (The ./configure script is likely to
-have set this to a directory which does not exist on your system.)
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.)
Build and install the runtime (bytecode) libraries by running:
-- % gmake -C runtime - % mkdir $CFEINSTALL/bytecode-libs - % gmake -C runtime install - % setenv LLVM_LIB_SEARCH_PATH $CFEINSTALL/bytecode-libs -- -
Test the newly-installed C frontend by one or more of the -following means:
-gmake -C
- test/Programs;
-
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