On 06/15/2012 11:49 PM, Vincent Torri wrote: >> This can be shortened: >> >> m4_pushdef([flagm4], m4_bpatsubst([[$2]], [no-])) >> >> since m4_bpatsubst is a no-op if the pattern 'no-' doesn't appear. >> > heh, as option=m4_bpatsubst([[$2]], [no-]) is working, there's no need. > It's so simple when you know how it works... > > I finally found the doc of that m4 macro, and it's not mentioned that > it's a no op in some cases: > > http://www.gnu.org/software/autoconf/manual/autoconf.html#Conditional-constructs > > > is it possible to add that ? Patches welcome, if you think it would help. The current documentation for m4_bpatsubst() just points to the GNU M4 manual for patsubst(): https://www.gnu.org/software/autoconf/manual/autoconf.html#Redefined-M4-Macros > > Also, if I'm not mistaken, there's a typo in the macro name : > > m4_bpatsubsts (final s) > ^ Wrong macro. m4_bpatsubsts() with the final s is a different macro, with even more power than m4_bpatsubst(). >> m4_foreach_w([flag], [$2], >> [EFL_CHECK_COMPILER_FLAG([$1], m4_defn([flag]))]) > > for $1, i was sure, but why is it not needed for m4_defn([flag]) ? Because you _want_ the m4_defn() to be expanded up front, and because the output of m4_defn is already quoted for reuse. In other words, you want to call: EFL_CHECK_COMPILER_FLAG([efl], [-Wfoo]) EFL_CHECK_COMPILER_FLAG([efl], [-Wno-bar]) and not: EFL_CHECK_COMPILER_FLAG([efl], [m4_defn([flag])]) EFL_CHECK_COMPILER_FLAG([efl], [m4_defn([flag])]) because the latter wouldn't be checking the right flag names. -- Eric Blake eblake@xxxxxxxxxx +1-919-301-3266 Libvirt virtualization library http://libvirt.org
Attachment:
signature.asc
Description: OpenPGP digital signature
_______________________________________________ Autoconf mailing list Autoconf@xxxxxxx https://lists.gnu.org/mailman/listinfo/autoconf
