# Copyright 2014 Cloudera, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# Find LLVM
#
# It defines the following variables
#  LLVM_FOUND        - True if llvm found.
#  LLVM_INCLUDE_DIRS - where to find llvm include files
#  LLVM_LIBRARY_DIRS - where to find llvm libs
#  LLVM_CFLAGS       - llvm compiler flags
#  LLVM_LDFLAGS      - llvm linker flags
#  LLVM_LIBS         - list of llvm libs for working with modules.

if(NOT DEFINED CLANG_ROOT)
  set(CLANG_ROOT $ENV{CLANG_ROOT})
endif()

foreach(prog_name llvm-config llvm-config-3.4)
  find_program(LLVM_CONFIG_EXECUTABLE ${prog_name} DOC "${prog_name} executable"
    HINTS ${CLANG_ROOT}/bin)
  if(LLVM_CONFIG_EXECUTABLE)
    break()
  endif()
endforeach(prog_name)

if(LLVM_CONFIG_EXECUTABLE)
  message(STATUS "LLVM llvm-config found at: ${LLVM_CONFIG_EXECUTABLE}")
elseif(LLVM_FIND_REQUIRED)
  message(FATAL_ERROR "Could NOT find llvm-config executable")
endif()

execute_process(
  COMMAND ${LLVM_CONFIG_EXECUTABLE} --version
  OUTPUT_VARIABLE LLVM_VERSION
  OUTPUT_STRIP_TRAILING_WHITESPACE
)

string(REGEX REPLACE "^([0-9]+)\\.([0-9]+).*" "\\1" LLVM_VERSION_MAJOR
	     "${LLVM_VERSION}")

string(REGEX REPLACE "^([0-9]+)\\.([0-9]+).*" "\\2" LLVM_VERSION_MINOR
	     "${LLVM_VERSION}")

execute_process(
  COMMAND ${LLVM_CONFIG_EXECUTABLE} --includedir
  OUTPUT_VARIABLE LLVM_INCLUDE_DIRS
  OUTPUT_STRIP_TRAILING_WHITESPACE
)

execute_process(
  COMMAND ${LLVM_CONFIG_EXECUTABLE} --libdir
  OUTPUT_VARIABLE LLVM_LIBRARY_DIRS
  OUTPUT_STRIP_TRAILING_WHITESPACE
)

execute_process(
  COMMAND ${LLVM_CONFIG_EXECUTABLE} --cppflags
  OUTPUT_VARIABLE LLVM_CFLAGS
  OUTPUT_STRIP_TRAILING_WHITESPACE
)

execute_process(
  COMMAND ${LLVM_CONFIG_EXECUTABLE} --ldflags
  OUTPUT_VARIABLE LLVM_LDFLAGS
  OUTPUT_STRIP_TRAILING_WHITESPACE
)

execute_process(
  COMMAND ${LLVM_CONFIG_EXECUTABLE} --libs ${LLVM_FIND_COMPONENTS}
  OUTPUT_VARIABLE LLVM_LIBS
  OUTPUT_STRIP_TRAILING_WHITESPACE
  )

set(LLVM_FOUND TRUE)