diff options
Diffstat (limited to 'docs/GettingStarted.rst')
| -rw-r--r-- | docs/GettingStarted.rst | 31 |
1 files changed, 18 insertions, 13 deletions
diff --git a/docs/GettingStarted.rst b/docs/GettingStarted.rst index 6de9b90..140210d 100644 --- a/docs/GettingStarted.rst +++ b/docs/GettingStarted.rst @@ -115,7 +115,6 @@ LLVM is known to work on the following host platforms: ================== ===================== ============= OS Arch Compilers ================== ===================== ============= -AuroraUX x86\ :sup:`1` GCC Linux x86\ :sup:`1` GCC, Clang Linux amd64 GCC, Clang Linux ARM\ :sup:`4` GCC, Clang @@ -331,10 +330,23 @@ of this information from. .. _GCC wiki entry: http://gcc.gnu.org/wiki/InstallingGCC -Once you have a GCC toolchain, use it as your host compiler. Things should -generally "just work". You may need to pass a special linker flag, -``-Wl,-rpath,$HOME/toolchains/lib`` or some variant thereof to get things to -find the libstdc++ DSO in this toolchain. +Once you have a GCC toolchain, configure your build of LLVM to use the new +toolchain for your host compiler and C++ standard library. Because the new +version of libstdc++ is not on the system library search path, you need to pass +extra linker flags so that it can be found at link time (``-L``) and at runtime +(``-rpath``). If you are using CMake, this invocation should produce working +binaries: + +.. code-block:: console + + % mkdir build + % cd build + % CC=$HOME/toolchains/bin/gcc CXX=$HOME/toolchains/bin/g++ \ + cmake .. -DCMAKE_CXX_LINK_FLAGS="-Wl,-rpath,$HOME/toolchains/lib64 -L$HOME/toolchains/lib64" + +If you fail to set rpath, most LLVM binaries will fail on startup with a message +from the loader similar to ``libstdc++.so.6: version `GLIBCXX_3.4.20' not +found``. This means you need to tweak the -rpath linker flag. When you build Clang, you will need to give *it* access to modern C++11 standard library in order to use it as your new host in part of a bootstrap. @@ -713,13 +725,6 @@ The following options can be used to set or enable LLVM specific options: generating the documentation can take a long time and producess 100s of megabytes of output. -``--with-udis86`` - - LLVM can use external disassembler library for various purposes (now it's used - only for examining code produced by JIT). This option will enable usage of - `udis86 <http://udis86.sourceforge.net/>`_ x86 (both 32 and 64 bits) - disassembler library. - To configure LLVM, follow these steps: #. Change directory into the object root directory: @@ -1013,7 +1018,7 @@ This directory contains most of the source files of the LLVM system. In LLVM, almost all code exists in libraries, making it very easy to share code among the different `tools`_. -``llvm/lib/VMCore/`` +``llvm/lib/IR/`` This directory holds the core LLVM source files that implement core classes like Instruction and BasicBlock. |