cmake extract substring from variable

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?

question from:https://stackoverflow.com/questions/65851799/cmake-extract-substring-from-variable

Answer 1

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