options-parser: provide a saner pluggable API.

It's much too easy to forget that the functions you hook into
the option parser need to return unconsumed options in the
variable `func_run_hooks_result'; better to follow the
convention used in the rest of bootstrap and return results in a
variable named after the function with `_result' appended.
* libltdl/config/options-parser (func_run_hooks): implement this
new API.
(Option parsing): Update the example in the header comment for
this section to reflect the changes.
* bootstrap (bootstrap_options_prep, bootstrap_parse_options)
(bootstrap_validate_options): Adjust.
* bootstrap.conf (libtool_options_prep, libtool_parse_options)
(libtool_validate_options): Ditto.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>

bootstrap

@@ -2336,17 +2336,14 @@ bootstrap_options_prep ()
 
     # Pass back the list of options we consumed.
     func_quote_for_eval ${1+"$@"}
-    func_run_hooks_result="$func_quote_for_eval_result"
+    bootstrap_options_prep_result="$func_quote_for_eval_result"
 }
 func_add_hook func_options_prep bootstrap_options_prep
 
 
 # bootstrap_parse_options [ARG]...
 # --------------------------------
-# Provide handling for Bootstrap specific options.  Note
-# `func_parse_options' passes in the unconsumed positional parameters, and
-# this function has to pass back whatever remains after its own
-# processing in the `func_run_hooks_result' variable.
+# Provide handling for Bootstrap specific options.
 bootstrap_parse_options ()
 {
     $debug_cmd
@@ -2417,7 +2414,7 @@ bootstrap_parse_options ()
 
     # save modified positional parameters for caller
     func_quote_for_eval ${1+"$@"}
-    func_run_hooks_result="$func_quote_for_eval_result"
+    bootstrap_parse_options_result="$func_quote_for_eval_result"
 }
 func_add_hook func_parse_options bootstrap_parse_options
 
@@ -2439,7 +2436,7 @@ bootstrap_validate_options ()
 
     # Pass back the list of unconsumed options left.
     func_quote_for_eval ${1+"$@"}
-    func_run_hooks_result="$func_quote_for_eval_result"
+    bootstrap_validate_options_result="$func_quote_for_eval_result"
 }
 
 

bootstrap.conf

@@ -177,7 +177,7 @@ Libtool Specific Options:
 
     # pass back the list of options we consumed
     func_quote_for_eval ${1+"$@"}
-    func_run_hooks_result="$func_quote_for_eval_result"
+    libtool_options_prep_result="$func_quote_for_eval_result"
 }
 func_add_hook func_options_prep libtool_options_prep
 
@@ -185,9 +185,7 @@ func_add_hook func_options_prep libtool_options_prep
 # libtool_parse_options [ARG...]
 # ------------------------------
 # Provide handling for additional Libtool options inside the main option
-# parsing loop.  Note that `bootstrap' passes in the current positional
-# parameters, and this function has to pass back whatever is left after
-# its own processing in the `func_run_hooks_result' variable.
+# parsing loop.
 libtool_parse_options ()
 {
     $debug_cmd
@@ -217,7 +215,7 @@ libtool_parse_options ()
 
     # pass back the list of options we consumed
     func_quote_for_eval ${1+"$@"}
-    func_run_hooks_result="$func_quote_for_eval_result"
+    libtool_parse_options_result="$func_quote_for_eval_result"
 }
 func_add_hook func_parse_options libtool_parse_options
 
@@ -246,7 +244,7 @@ libtool_validate_options ()
 
     # pass back the list of options we consumed
     func_quote_for_eval ${1+"$@"}
-    func_run_hooks_result="$func_quote_for_eval_result"
+    libtool_validate_options_result="$func_quote_for_eval_result"
 }
 func_add_hook func_validate_options libtool_validate_options
 

libltdl/config/options-parser

@@ -1,7 +1,7 @@
 #! /bin/sh
 
 # Set a version string for this script.
-scriptversion=2011-11-04.03; # UTC
+scriptversion=2011-11-16.05; # UTC
 
 # A pluggable option parser for Bourne shell.
 # Written by Gary V. Vaughan, 2010
@@ -272,20 +272,18 @@ func_run_hooks ()
       *) func_fatal_error "\`$1' does not support hook funcions.n" ;;
     esac
 
-    eval _G_hook_fns="\$$1_hooks"
-
-    # shift away the first argument (FUNC_NAME)
-    shift
-    func_quote_for_eval ${1+"$@"}
-    func_run_hooks_result=$func_quote_for_eval_result
+    eval _G_hook_fns="\$$1_hooks"; shift
 
     for _G_hook in $_G_hook_fns; do
       eval $_G_hook '"$@"'
 
       # store returned options list back into positional
       # parameters for next `cmd' execution.
-      eval set dummy $func_run_hooks_result; shift
+      eval set dummy \$${_G_hook}_result; shift
     done
+
+    func_quote_for_eval ${1+"$@"}
+    func_run_hooks_result=$func_quote_for_eval_result
 }
 
 
@@ -297,8 +295,8 @@ func_run_hooks ()
 # In order to add your own option parsing hooks, you must accept the
 # full positional parameter list in your hook function, remove any
 # options that you action, and then pass back the remaining unprocessed
-# options in `func_run_hooks_result', escaped suitably for `eval'.  Like
-# this:
+# options in `<hooked_function_name>_result', escaped suitably for
+# `eval'.  Like this:
 #
 #    my_options_prep ()
 #    {
@@ -310,7 +308,7 @@ func_run_hooks ()
 #    '
 #
 #        func_quote_for_eval ${1+"$@"}
-#        func_run_hooks_result=$func_quote_for_eval_result
+#        my_options_prep_result=$func_quote_for_eval_result
 #    }
 #    func_add_hook func_options_prep my_options_prep
 #
@@ -337,7 +335,7 @@ func_run_hooks ()
 #        done
 #
 #        func_quote_for_eval ${1+"$@"}
-#        func_run_hooks_result=$func_quote_for_eval_result
+#        my_silent_option_result=$func_quote_for_eval_result
 #    }
 #    func_add_hook func_parse_options my_silent_option
 #
@@ -350,8 +348,9 @@ func_run_hooks ()
 #    \`--silent' and \`--verbose' options are mutually exclusive."
 #
 #        func_quote_for_eval ${1+"$@"}
-#        func_run_hooks_result=$func_quote_for_eval_result
+#        my_option_validation_result=$func_quote_for_eval_result
 #    }
+#    func_add_hook func_validate_options my_option_validation
 #
 # You'll alse need to manually amend $usage_message to reflect the extra
 # options you parse.  It's preferable to append if you can, so that