cmake extract substring from variable - cmake

Question

I have variable CC_OPTIONS has value set like below
-arch arm64 -mcpu=abc1 -c --debug -O2 -static -fstack-protector -ffreestanding -nostartfiles -std=c11
I wanted to extract -mcpu=abc1 from CC_OPTIONS
Tried below approach, but getting more than what i wanted.
string(REGEX REPLACE ".*mcpu=(.*)\ .*" "\\1" CPU_TYPE "${CC_OPTIONS}")
any suggestions?

Answer 1

If you use if(MATCHES) you can get character groups of the match using CMAKE_MATCH_<n>
set(MY_VAR "-arch arm64 -mcpu=abc1 -c --debug -O2 -static -fstack-protector -ffreestanding -nostartfiles -std=c11")
if (MY_VAR MATCHES "^([^ ]+ +)*(-mcpu=[^ ]+)( +[^ ]+)*$")
message(STATUS "Found match: ${CMAKE_MATCH_2}")
else()
message(FATAL_ERROR "mismatch")
endif()

Answer 2

Like that:
cmake_minimum_required (VERSION 2.8.11)
project (HELLO)
set(CC_OPTIONS "-arch arm64 -mcpu=abc1 -c --debug -O2 -static -fstack-protector -ffreestanding -nostartfiles -std=c11")
message(${CC_OPTIONS})
string(REGEX MATCH "\\-mcpu=[^ $]+" CPU_TYPE ${CC_OPTIONS})
message(${CPU_TYPE})
Example:
$ cmake .
-arch arm64 -mcpu=abc1 -c --debug -O2 -static -fstack-protector -ffreestanding -nostartfiles -std=c11
-mcpu=abc1
-- Configuring done
-- Generating done
-- Build files have been written to: /home/ja/cmake