1# --------------------------------------------------------------------------- 2# Provide various compatibility macros for older Autoconf machines 3# Definitions were copied from the Autoconf source code. 4# --------------------------------------------------------------------------- 5m4_ifdef([AS_VAR_IF],,m4_define([AS_VAR_IF], 6[AS_LITERAL_WORD_IF([$1], 7 [AS_IF(m4_ifval([$2], [[test "x$$1" = x[]$2]], [[${$1:+false} :]])], 8 [AS_VAR_COPY([as_val], [$1]) 9 AS_IF(m4_ifval([$2], [[test "x$as_val" = x[]$2]], [[${as_val:+false} :]])], 10 [AS_IF(m4_ifval([$2], 11 [[eval test \"x\$"$1"\" = x"_AS_ESCAPE([$2], [`], [\"$])"]], 12 [[eval \${$1:+false} :]])]), 13[$3], [$4])]))dnl 14