CODEWITHSUNDEEP
cmakefile
gfbio
gfbio

Reputation: 1546

Add compiler option without editing Makefile

I should compile a program written in C through a Makefile. I should insert into the Makefile, some option, for instance: -O2, -march=i686. How can I insert this option in the Makefile without writing into it?

Upvotes: 30

Views: 47299

Answers (1)

dirkgently
dirkgently

Reputation: 111130

You should use a macro like CFLAGS. Check out GNU GCC documentation.

Something like this should work:

CFLAGS := $(CFLAGS) -O2 -march=i686

Or, if you prefer not to modify the makefile use:

make CFLAGS='-O2 -march=i686'

The other options will be picked up automatically though. See overriding variables.

Upvotes: 26

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