1 files changed, 109 insertions, 0 deletions
diff --git a/tools/build/src/util/option.jam b/tools/build/src/util/option.jam
new file mode 100644
index 000000000..f6dc37522
--- /dev/null
+++ b/tools/build/src/util/option.jam
@@ -0,0 +1,109 @@
+#  Copyright (c) 2005 Vladimir Prus.
+#
+#  Use, modification and distribution is subject to the Boost Software
+#  License Version 1.0. (See accompanying file LICENSE_1_0.txt or
+#  http://www.boost.org/LICENSE_1_0.txt)
+
+import modules ;
+
+# Set a value for a named option, to be used when not overridden on the command
+# line.
+rule set ( name : value ? )
+{
+    .option.$(name) = $(value) ;
+}
+
+rule get ( name : default-value ? : implied-value ? )
+{
+    local m = [ MATCH --$(name)=(.*) : [ modules.peek : ARGV ] ] ;
+    if $(m)
+    {
+        return $(m[1]) ;
+    }
+    else  
+    {        
+        m = [ MATCH (--$(name)) : [ modules.peek : ARGV ] ] ;
+        if $(m) && $(implied-value)
+        {
+            return $(implied-value) ;
+        }
+        else if $(.option.$(name))
+        {
+            return $(.option.$(name)) ;
+        }    
+        else
+        {
+            return $(default-value) ;
+        }    
+    }              
+}
+
+
+# Check command-line args as soon as possible. For each option try to load
+# module named after option. Is that succeeds, invoke 'process' rule in the
+# module. The rule may return "true" to indicate that the regular build process
+# should not be attempted.
+#
+# Options take the general form of: --<name>[=<value>] [<value>]
+#
+rule process ( )
+{
+    local ARGV = [ modules.peek : ARGV ] ;
+    local BOOST_BUILD_PATH = [ modules.peek : BOOST_BUILD_PATH ] ;
+
+    local dont-build ;
+    local args = $(ARGV) ;
+    while $(args)
+    {
+        local arg = [ MATCH ^--(.*) : $(args[1]) ] ;
+        while $(args[2-]) && ! $(arg)
+        {
+            args = $(args[2-]) ;
+            arg = [ MATCH ^--(.*) : $(args[1]) ] ;
+        }
+        args = $(args[2-]) ;
+
+        if $(arg)
+        {
+            local split = [ MATCH ^(([^-=]+)[^=]*)(=?)(.*)$ : $(arg) ] ;
+            local full-name = $(split[1]) ;
+            local prefix = $(split[2]) ;
+            local values ;
+
+            if $(split[3])
+            {
+                values = $(split[4]) ;
+            }
+            if $(args) && ! [ MATCH ^(--).* : $(args[1]) ]
+            {
+                values += $(args[1]) ;
+                args = $(args[2-]) ;
+            }
+
+            # Jook in options subdirectories of BOOST_BUILD_PATH for modules
+            # matching the full option name and then its prefix.
+            local plugin-dir = options ;
+            local option-files = [ GLOB $(plugin-dir:D=$(BOOST_BUILD_PATH)) :
+                $(full-name).jam $(prefix).jam ] ;
+
+            if $(option-files)
+            {
+                # Load the file into a module named for the option.
+                local f = $(option-files[1]) ;
+                local module-name = --$(f:D=:S=) ;
+                modules.load $(module-name) : $(f:D=) : $(f:D) ;
+
+                # If there is a process rule, call it with the full option name
+                # and its value (if any). If there was no "=" in the option, the
+                # value will be empty.
+                if process in [ RULENAMES $(module-name) ]
+                {
+                    dont-build += [ modules.call-in $(module-name) : process
+                        --$(full-name) : $(values) ] ;
+                }
+            }
+        }
+    }
+
+    return $(dont-build) ;
+}