Added a read me to guide folks through the freeBSD build process.

Author: ianamason

README-freeBSD.md

@@ -0,0 +1,160 @@
+Steps to build bitcode version of FreeBSD 10.0 world and kernel
+-----------------------------------------------
+
+The following instructions have been tested with FreeBSD 10.0 amd64.
+
+-- Prerequisites: --------------------------------------------------------------
+
+1. FreeBSD
+
+The ideal way to start is with a clean install of FreeBSD 10.0 with 
+sources installed. The simplest way to do this is to install from the 
+Release 10.0 ISO image and and on the "Distribution Select" screen 
+select just the following:
+
+  [*] ports   Ports tree
+  [*] src     System source code
+
+If you are on an existing system that has either an old version of the 
+source tree or is missing source, you can follow the instructions in the 
+FreeBSD Handbook Chapter 24 to get the relevant sources.
+
+2. Necessary ports
+
+Upgrade the ports collection (as 'root'):
+
+   su -
+   portsnap fetch
+   portsnap extract
+   cd /usr/ports/ports-mgmt/portupgrade
+   make -DBATCH install clean
+   portupgrade -a --batch
+
+Install the following ports using the BSD port tree: 
+
+  bash git subversion python27 sudo wget
+
+(See the FreeBSD Handbook Chapter 5 for instructions.)
+The quick way to do this is:
+
+   su -
+   cd /usr/ports
+   cd shells/bash && make -DBATCH install clean && \
+     cd ../../devel/git && make -DBATCH install clean && \
+     cd ../../devel/subversion && make -DBATCH install clean && \
+     cd ../../security/sudo && make -DBATCH install clean && \
+     cd ../../ftp/wget && make -DBATCH install clean
+
+(Python27 is installed as a prerequisite of Subversion.)
+
+Below we assume the shell being used is bash, that is:
+
+   chsh -s /usr/local/bin/bash
+
+has been run. If you want to use another shell, replace bash-isms like 
+'export' with the appropriate equivalent.
+
+We suggest installing 'sudo' and setting up your account as a sudoer, to 
+make installing programs easier. You can do this, or modify the commands 
+that use 'sudo' below.
+
+3. LLVM and Clang 3.3
+
+Install LLVM and Clang version 3.3. (These instructions adapted from 
+http://llvm.org/docs/GettingStarted.html) Decide where you want to 
+install LLVM. If you have 'root' access, you can use the default 
+'/usr/local', though any location is fine. You may then wish to add this 
+to your shell startup (in '~/.profile' for bash):
+
+  export LLVM_HOME=/usr/local/llvm-3.3
+
+Get LLVM and Clang version 3.5:
+
+  svn co http://llvm.org/svn/llvm-project/llvm/branches/release_33 llvm
+  cd llvm/tools
+  svn co http://llvm.org/svn/llvm-project/cfe/branches/release_33 clang
+  cd ../projects
+  svn co http://llvm.org/svn/llvm-project/compiler-rt/branches/release_33 compiler-rt
+  cd ../..
+
+Now finish the build and install:
+
+  cd llvm
+  mkdir build
+  cd build
+  ../configure --prefix=$LLVM_HOME --enable-assertions \
+      --enable-targets=host-only --enable-optimized
+  gmake 
+  sudo gmake install
+
+Note that the FreeBSD 10.0 base includes Clang 3.3 (but does not include 
+the complete LLVM framework, in particular llvm-link is not included).
+
+So to make life easier, so that extract-bc can find it do:
+
+  sudo ln -s $LLVM_HOME/bin/llvm-link /usr/bin/llvm-link
+  
+
+1. Download SRI-modified version of WLLVM.
+
+> cd ${HOME}
+> git clone https://github.com/SRI-CSL/whole-program-llvm
+
+2. Create the hooks for interposing on compiler calls.
+
+> cd ${HOME}
+> mkdir ${HOME}/wllvm.bin
+> cd wllvm.bin
+> ln -s ${HOME}/whole-program-llvm/wllvm cc
+> ln -s ${HOME}/whole-program-llvm/wllvm++ c++
+> ln -s ${HOME}/whole-program-llvm/wllvm clang
+> ln -s ${HOME}/whole-program-llvm/wllvm++ clang++
+this next one is a hack (make buildworld doesn't find python with /usr/bin/env without it)
+> ln -s /usr/local/bin/python python
+
+3. Insert the hooks into the build path.
+
+> diff /usr/src/Makefile.inc1 Makefile.inc1.original 
+180c180
+< BPATH=	${HOME}/wllvm.bin:${WORLDTMP}/legacy/usr/sbin:${WORLDTMP}/legacy/usr/bin:${WORLDTMP}/legacy/usr/games:${WORLDTMP}/legacy/bin
+---
+> BPATH=	${WORLDTMP}/legacy/usr/sbin:${WORLDTMP}/legacy/usr/bin:${WORLDTMP}/legacy/usr/games:${WORLDTMP}/legacy/bin
+
+4. If the build location doesn't exist, create it.
+
+> mkdir ${HOME}/build.world
+
+5. Configure the environment for the build.
+
+> export MAKEOBJDIRPREFIX=${HOME}/build.world
+> export LLVM_COMPILER=clang
+> export LLVM_COMPILER_PATH=/usr/bin
+> export WLLVM_OUTPUT=DEBUG
+
+6. Start the build.
+
+> cd /usr/src
+> make buildworld
+
+7. Once that succeeds build the kernel
+
+> make buildkernel
+
+
+8. extract the bitcode:
+
+
+cd  ${MAKEOBJDIRPREFIX}/usr/src/sys/GENERIC
+
+> ${HOME}/whole-program-llvm/extract-bc kernel
+
+> nm kernel | wc
+   53140  159418 2421852
+
+> ${LLVM_HOME}/bin/llvm-nm kernel.bc | wc
+   50664  101328 1910997
+
+We are working on seeing if we can get these numbers to match.
+But suspect their is some assembler causing this difference.
+
+