AX_NUMERIC_NAMEDLEVEL(VARNAME [,FROMVAR [,DEFAULT [,YESLEVEL]]])
The levelstring FROMVAR is expanded and checked for verbal names that will map on to eight different levels - the VARNAME will receive this numeric level where "all" maps to 7 (lower three bits set) higher levels for 8 and 9 exist too. This macro is a nice helper to convert user input of a –with-opt=level into a numeric form that can be simply pushed as a #define like with AC_DEFINE:
default YESLEVEL = 2 /* including unknown levelspec */ default DEFAULT = 0 /* when named level is empty */ default FROMVAR = VARNAME
The DEFAULT value is used if the NAMED levelstring has become empty and it is copied without further conversion - a default of "0" is used if absent - identical to "no". A "yes" will be set to the YESLEVEL - and note that "yes" has "2" as its default value not "1". (which comes from its original use to set a "gcc -O2").
the mnemonic names are:
9| insane |ultrasome|experimentalplus 8| ultra |ultra|experimental) 7| all |muchmore|somemanymore|manymoreplus 6| most |manymore|most) 5| strict |somemore|almost 4| more |more 3| extra |manyplus|plusmuch|somemany|plusmany 2| many |many|much|(yes) 1| some |some|plus
note that a level can be constructed of (some|plus) = bit-0, (many|much) = bit-1, (more) = bit-2, (ultra|experimental) = bit-3 at least in a left-to-right order, ie. plusmanymore=7
AX_NUMERIC_NAMEDLEVEL(OPTLEVEL,with_optlevel,1,3) AC_DEFINE(OPTLEVEL) test "$GCC" = "yes" && CFLAGS="$CFLAGS -O$OPTLEVEL)
Download the latest version of ax_numeric_namedlevel.m4 or browse the macro’s revision history.
Copyright © 2008 Guido U. Draheim email@example.com
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