Re: default make rules

[Julio Merino <julio%meroh.net@localhost>]

On Tue, Sep 18, 2012 at 8:25 PM, James K. Lowden
<jklowden%schemamania.org@localhost> wrote:
> How does make compose CXXFLAGS and LDFLAGS by default?
>
> $ touch src.C
> $ CXXFLAGS=cxxflags LDFLAGS=ldflags make -n src
> c++ cxxflags  ldflags -o src src.C
>
> In general that's not good because the linker options need to follow
> the source filename on the command line.  Otherwise at least some
> symbols will be missed sometimes.

Nope.  What need to follow the source filename are the libraries, no
the linker options.  That's why there usually is a LIBS variable
(LDLIBS in NetBSD) that contains the -l and .a arguments, and LDFLAGS
contains only things like -L or rpaths.

> AFAICT this is controlled by /usr/share/mk/sys.mk:
>
>         LINK.cc?=       ${CXX} ${CXXFLAGS} ${CPPFLAGS} ${LDFLAGS}

But this is later used as:

${LINK.cc} -o ${.TARGET} ${.IMPSRC} ${LDLIBS}

-- 
Julio Merino / @jmmv