* configure: Restructuring configure script to be able to detect

nonexistent options. Variable default values are established first,
which simplifies the syntax. The scanning loop detects attempts
to create configuration variables that do not exist.
The var_given convention is folded into the parsing. (If var
exists, and var_given exists, and the user specifies var,
then var_given is set to y to indicate that the value came
from the user.)

1 files changed, 65 insertions, 51 deletions

diff --git a/configure b/configure
index c6552968..cca35bda 100755
--- a/configure
+++ b/configure
@@ -47,6 +47,58 @@ for arg in "$0" ${@+"$@"} ; do
 done
 
 #
+# Establish default values for any variables that are not specified
+# on the command line. The default derivations from prefix are in
+# Make syntax. They go verbatim into the generated config.make.
+# This way they can be overridden more flexibly at make time.
+#
+
+#
+# non-config
+#
+help=
+
+#
+# config
+#
+prefix=/usr/local
+install_prefix=
+bindir='$(prefix)/bin'
+datadir='$(prefix)/share/txr'
+mandir='$(prefix)/share/man'
+make=
+cross=
+compiler_prefix=
+ccname=gcc
+cc='$(cross)$(compiler_prefix)$(ccname)'
+intptr=
+tool_prefix=
+lex='$(cross)$(tool_prefix)flex'
+lexlib=-lfl
+yaccname_given=
+yaccname=
+yacc='$(cross)$(tool_prefix)$(yaccname)'
+yacc_given=
+nm='$(cross)$(tool_prefix)nm'
+opt_flags=-O2
+lang_flags='--ansi -D_XOPEN_SOURCE=2'
+diag_flags='-Wall -Wmissing-prototypes -Wstrict-prototypes'
+debug_flags=-g
+inline=
+platform_flags=
+remove_flags=
+lex_dbg_flags=
+txr_dbg_opts=--gc-debug
+valgrind=
+lit_align=
+extra_debugging=
+debug_support=y
+gen_gc=
+mpi_version=1.8.6
+have_quilt=
+have_patch=
+
+#
 # Parse configuration variables
 #
 while [ $# -gt 0 ] ; do
@@ -89,61 +141,23 @@ while [ $# -gt 0 ] ; do
     exit 1
   fi
 
+  eval "var_exists=\${$var+y}"
+
+  if [ "$var_exists" != y ] ; then
+    printf "$0: nonexistent option: '%s'\n" "$1"
+    exit 1
+  fi
+
   eval "$var='$val'"
-  shift
-done
 
-#
-# Establish default values for any variables that are not specified
-# on the command line. The default derivations from prefix are in
-# Make syntax. They go verbatim into the generated config.make.
-# This way they can be overridden more flexibly at make time.
-#
+  eval "var_given_exists=\${${var}_given+y}"
 
-#
-# non-config
-#
-help=${help-}
+  if [ "$var_given_exists" = y ] ; then
+    eval "${var}_given=y"
+  fi
 
-#
-# config
-#
-prefix=${prefix-/usr/local}
-install_prefix=${install_prefix-}
-bindir=${datadir-'$(prefix)/bin'}
-datadir=${datadir-'$(prefix)/share/txr'}
-mandir=${mandir-'$(prefix)/share/man'}
-make=${make-}
-cross=${cross-}
-compiler_prefix=${compiler_prefix-}
-ccname=${ccname-gcc}
-cc=${cc-'$(cross)$(compiler_prefix)$(ccname)'}
-intptr=${intptr-}
-tool_prefix=${tool_prefix-}
-lex=${lex-'$(cross)$(tool_prefix)flex'}
-lexlib=${lexlib--lfl}
-yaccname_given=${yaccname+y}
-yaccname=${yaccname-}
-yacc_given=${yacc+y}
-yacc=${yacc-'$(cross)$(tool_prefix)$(yaccname)'}
-nm=${nm-'$(cross)$(tool_prefix)nm'}
-opt_flags=${opt_flags--O2}
-lang_flags=${lang_flags--ansi -D_XOPEN_SOURCE=2}
-diag_flags=${diag_flags--Wall -Wmissing-prototypes -Wstrict-prototypes}
-debug_flags=${debug_flags--g}
-inline=${inline-}
-platform_flags=${platform_flags-}
-remove_flags=${remove_flags-}
-lex_dbg_flags=${lex_dbg_flags-}
-txr_dbg_opts=${txr_dbg_opts---gc-debug}
-valgrind=${valgrind-}
-lit_align=${lit_align-}
-extra_debugging=${extra_debugging-}
-debug_support=${debug_support-y}
-gen_gc=${gen_gc-}
-mpi_version=1.8.6
-have_quilt=
-have_patch=
+  shift
+done
 
 #
 # If --help was given (or --help=<nonempty> or help=<nonempty>) then