Hello Jim, all, sorry for chiming in late.
* Jim Meyering wrote on Thu, Oct 15, 2009 at 09:06:16PM CEST: > Subject: [PATCH] don't let environment settings perturb build > > Setting the envvars, LIB_CLOCK_GETTIME, LIB_EACCESS or LIB_NANOSLEEP > could cause a configure-time and/or build-time malfunction. > Typically, a configure-time function-in-library test is performed > via code like this: > > LIB_VAR= > AC_SUBST([LIB_VAR]) > prefix_saved_LIBS=$LIBS > AC_SEARCH_LIBS([FUNC], [LIB_NAME], > [test "$ac_cv_search_FUNC" = "none required" || > LIB_VAR=$ac_cv_search_FUNC]) > LIBS=$prefix_saved_LIBS > > However, in each of the files affected by this change, the LIB_VAR= > initialization was omitted. Thus, when set in the environment, its > value would propagate into generated Makefiles when FUNC is not found > in LIB_NAME. Wouldn't it be just as consistent to just document that LIB_<VAR> can be used to override the respective macro, for systems on which a library other than one known to the macro, may be needed? That would be in line with how many Autoconf macros work: the AC_SUBSTed variable may be overridden by the knowledgeable end user, who may know better than the macro author. Aside, have you experienced a configure-time and/or build-time malfunction with this? > * m4/clock_time.m4 (gl_CLOCK_TIME): Initialize AC_SUBST'd var. > * m4/euidaccess.m4 (gl_PREREQ_EUIDACCESS): Likewise. > * m4/nanosleep.m4 (gl_FUNC_NANOSLEEP): Likewise. Cheers, Ralf
