llvm/runtimes/CMakeLists.txt
Chris Bieneman f444c52628 [CMake] Add LLVM runtimes directory
Summary:
There are a few LLVM projects that produce runtime libraries. Ideally
runtime libraries should be built differently than other projects,
specifically they should be built using the just-built toolchain.

There is support for building compiler-rt in this way from the clang
build. Moving this logic into the LLVM build is interesting because it
provides a simpler way to extend the just-built toolchain to include
LLD and the LLVM object file tools.

Once this functionality is better fleshed out and tested we’ll want to
encapsulate it in a module that can be used for clang standalone
builds, and we’ll want to make it the default way to build compiler-rt.

With this patch applied there is no immediate change in the build.
Moving compiler-rt out from llvm/projects into llvm/runtimes enables
the functionality.

This code has a few improvements over the method provided by
LLVM_BUILD_EXTERNAL_COMPILER_RT. Specifically the sub-ninja command is
always invoked, so changes to compiler-rt source files will get built
properly, so this patch can be used for iterative development with
just-built tools.

This first patch only works with compiler-rt. Support for other
runtime projects will be coming in follow-up patches.

Reviewers: chandlerc, bogner

Subscribers: kubabrecka, llvm-commits

Differential Revision: http://reviews.llvm.org/D20992

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273620 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-23 22:07:21 +00:00

91 lines
3.7 KiB
CMake

# This file handles building LLVM runtime sub-projects.
# Runtimes are different from tools or other drop-in projects because runtimes
# should be built with the LLVM toolchain from the build directory. This file is
# a first step to formalizing runtime build interfaces.
# In the current state this file only works with compiler-rt, other runtimes
# will work as the runtime build interface standardizes.
# Find all subdirectories containing CMake projects
file(GLOB entries *)
foreach(entry ${entries})
if(IS_DIRECTORY ${entry} AND EXISTS ${entry}/CMakeLists.txt)
list(APPEND runtimes ${entry})
endif()
endforeach()
# If this file is acting as a top-level CMake invocation, this code path is
# triggered by the external project call for the runtimes target below.
if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
cmake_minimum_required(VERSION 3.4.3)
# Add the root project's CMake modules, and the LLVM build's modules to the
# CMake module path.
list(INSERT CMAKE_MODULE_PATH 0
"${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
"${CMAKE_CURRENT_SOURCE_DIR}/../cmake/Modules"
"${LLVM_BINARY_DIR}/lib/cmake/llvm"
)
# LLVMConfig.cmake contains a bunch of CMake variables from the LLVM build.
# This file is installed as part of LLVM distributions, so this can be used
# either from a build directory or an installed LLVM.
include(LLVMConfig)
# Setting these variables will allow the sub-build to put their outputs into
# the library and bin directories of the top-level build.
set(LLVM_LIBRARY_OUTPUT_INTDIR ${LLVM_LIBRARY_DIR})
set(LLVM_RUNTIME_OUTPUT_INTDIR ${LLVM_BINARY_DIR})
foreach(entry ${runtimes})
get_filename_component(projName ${entry} NAME)
# TODO: Clean this up as part of an interface standardization
string(REPLACE "-" "_" canon_name ${projName})
string(TOUPPER ${canon_name} canon_name)
# The subdirectories need to treat this as standalone builds
set(${canon_name}_STANDALONE_BUILD On)
add_subdirectory(${projName})
endforeach()
else() # if this is included from LLVM's CMake
include(LLVMExternalProjectUtils)
# If compiler-rt is present we need to build the builtin libraries first. This
# is required because the other runtimes need the builtin libraries present
# before the just-built compiler can pass the configuration tests.
if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/compiler-rt)
llvm_ExternalProject_Add(builtins
${CMAKE_CURRENT_SOURCE_DIR}/compiler-rt/lib/builtins
PASSTHROUGH_PREFIXES COMPILER_RT
USE_TOOLCHAIN)
set(deps builtins)
endif()
# We create a list the names of all the runtime projects in all uppercase and
# with dashes turned to underscores. This gives us the CMake variable prefixes
# for all variables that will apply to runtimes.
foreach(entry ${runtimes})
get_filename_component(projName ${entry} NAME)
string(REPLACE "-" "_" canon_name ${projName})
string(TOUPPER ${canon_name} canon_name)
list(APPEND prefixes ${canon_name})
endforeach()
if(runtimes)
# Create a runtimes target that uses this file as its top-level CMake file.
# The runtimes target is a configuration of all the runtime libraries
# together in a single CMake invocaiton.
llvm_ExternalProject_Add(runtimes
${CMAKE_CURRENT_SOURCE_DIR}
DEPENDS ${deps} llvm-config
# Builtins were built separately above
CMAKE_ARGS -DCOMPILER_RT_BUILD_BUILTINS=Off
PASSTHROUGH_PREFIXES ${prefixes}
USE_TOOLCHAIN)
endif()
endif()