Add support for CPPFLAGS in Makefile about llmnrd HOT 8 CLOSED

Even with ab7cd2f it does not work:

$ make Q= CPPFLAGS="-D_FORTIFY_SOURCE=2" CFLAGS="-O2"
echo "  CC llmnr.c" && gcc -O2 -o llmnr.o -c llmnr.c
...

-D_FORTIFY_SOURCE=2 is still not used.

from llmnrd.

The problem seems to be the equal sign in -D_FORTIFY_SOURCE=2, e.g.

$ make Q= CPPFLAGS="-D_FORTIFY_SOURCE"
echo "  CC llmnr.c" && gcc -W -Wall -O2 -D_FORTIFY_SOURCE -DVERSION_STRING=\"v0.2.1\" -DGIT_VERSION=\""(git id v0.2.1-6-gab7cd2fc9043)"\" -o llmnr.o -c llmnr.c

work fine. Try escaping the passed value accordingly.

from llmnrd.

Does not work

$ make Q= CPPFLAGS="-D_FORTIFY_SOURCE" CFLAGS="-O2"
echo "  CC llmnr.c" && gcc -O2 -o llmnr.o -c llmnr.c

Problems looks like that your Makefile pass CPPFLAGS into CFLAGS, so if CFLAGS are specified outside of Makefile then CPPFLAGS are not used.

Another example via passing as envs to make:

$ Q= CPPFLAGS="-D_FORTIFY_SOURCE" CFLAGS="-g" make
echo "  CC llmnr.c" && gcc -g -DVERSION_STRING=\"v0.2.1\" -DGIT_VERSION=\""(git id v0.2.1-6-gab7cd2f)"\" -o llmnr.o -c llmnr.c
  CC llmnr.c

from llmnrd.

This is intended behavior at the moment, since we override CFLAGS - not append to it. This way, CPPFLAGS can no longer be used.

Would you expect CFLAGS specified on the command line to be appended?

from llmnrd.

It is common behavior that build script exports CPPFLAGS, CFLAGS and LDFLAGS env variables and run make. Lot of distributions are building packages in this way.

from llmnrd.

Yes, I see that. But do they commonly assume CFLAGS/CPPFLAGS/LDFLAGS override or append behaviour?

from llmnrd.

All those variables are independent. CFLAGS are "compiler" flag (e.g. -O2 or -g or -W-some-gcc-specific-flag); CPPFLAGS contains only defines (e.g. -DSOMETHING) and LDFLAGS are linker specific flags (e.g. -lm or -Wl,-some-ld-specific-flag). So Makefile should use all variables (in append mode) and not override one by another.

from llmnrd.

Commit 6281d3c should now fix it to behave as you expect. Thanks!

from llmnrd.