[llvm] r184924 - Provide bootstrap support to build only llvm+clang when using cmake.

[Andy Gibbs]

Author: andyg
Date: Wed Jun 26 03:05:08 2013
New Revision: 184924

URL: http://llvm.org/viewvc/llvm-project?rev=184924&view=rev
Log:
Provide bootstrap support to build only llvm+clang when using cmake.

Where a source tree is complete with lld, lldb and polly, it may not be possible to use cmake to configure build scripts if the host compiler it not capable of compiling these sub-projects.  This change makes it possible to first build a bootstrap clang compiler when can then be used to build a complete llvm toolchain.  An example bootstrap build sequence could be as follows:

$ mkdir bootstrap
$ cd bootstrap
$ cmake -G 'Unix Makefiles'
        -DCMAKE_BUILD_TYPE:STRING=Release
        -DCMAKE_PREFIX_PATH:STRING=$(pwd)
        -DLLVM_TARGETS_TO_BUILD:STRING=host
        -DLLVM_INCLUDE_TOOLS:STRING=bootstrap-only
        ../source
$ make clang  # build clang only for host

$ cd ..
$ export CC=$(realpath bootstrap/bin)/clang
$ export CXX=$(realpath bootstrap/bin)/clang++

$ mkdir final
$ cd final
$ cmake -G 'Unix Makefiles' ../source
$ make all check-all

Modified:
    llvm/trunk/tools/CMakeLists.txt

Modified: llvm/trunk/tools/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/CMakeLists.txt?rev=184924&r1=184923&r2=184924&view=diff
==============================================================================
--- llvm/trunk/tools/CMakeLists.txt (original)
+++ llvm/trunk/tools/CMakeLists.txt Wed Jun 26 03:05:08 2013
@@ -58,8 +58,11 @@ if( LLVM_ENABLE_PIC )
 endif()
 
 add_llvm_external_project(clang)
-add_llvm_external_project(lld)
-add_llvm_external_project(lldb)
-add_llvm_external_project(polly)
+
+if( NOT LLVM_INCLUDE_TOOLS STREQUAL "bootstrap-only" )
+  add_llvm_external_project(lld)
+  add_llvm_external_project(lldb)
+  add_llvm_external_project(polly)
+endif()
 
 set(LLVM_COMMON_DEPENDS ${LLVM_COMMON_DEPENDS} PARENT_SCOPE)