"symlink" targets.

[SVN r16332]

src/tools/builtin.jam

@@ -18,6 +18,7 @@ import stage ;
 import prebuilt ;
 import toolset ;
 import errors : error ;
+import symlink ;
 
 feature toolset : gcc : implicit propagated link-incompatible ;
 feature shared : false true : propagated ;

src/tools/symlink.jam

@@ -0,0 +1,105 @@
+#  Copyright (C) 2002, Rene Rivera. Permission to copy, use, modify, sell and
+#  distribute this software is granted provided this copyright notice appears in
+#  all copies. This software is provided "as is" without express or implied
+#  warranty, and with no claim as to its suitability for any purpose.
+
+# Defines the "symlink" special target. 'symlink' targets make symbolic links
+# to the sources.
+
+import numbers ;
+import targets ;
+import virtual-target ;
+import class ;
+import property ;
+import modules ;
+import os ;
+
+count = 0 ;
+
+# The class representing "symlink" targets.
+#
+rule symlink-targets (
+    project
+    : targets *
+    : sources *
+    )
+{
+    # Generate a fake name for now. Need unnamed targets eventually.
+    local c = [ modules.peek symlink : count ] ;
+    modules.poke symlink : count : [ numbers.increment $(c) ] ;
+    local fake-name = symlink#$(c) ;
+    
+    basic-target.__init__ $(fake-name) : $(project) : $(sources) ;
+    
+    # Remember the targets to map the sources onto. Pad or truncate
+    # to fit the sources given.
+    self.targets = ;
+    for local source in $(sources)
+    {
+        if $(targets)
+        {
+            self.targets += $(targets[1]) ;
+            targets = $(targets[2-]) ;
+        }
+        else
+        {
+            self.targets += $(source) ;
+        }
+    }
+    
+    # The virtual targets corresponding to the given targets.
+    self.virtual-targets = ;
+    
+    rule construct ( source-targets * : properties * )
+    {
+        local i = 1 ;
+        for local t in $(source-targets)
+        {
+            local s = $(self.targets[$(i)]) ;
+            local vt = [ class.new virtual-target $(s) : [ $(t).type ] : $(self.project) ] ;
+            $(vt).action [ class.new action $(vt) : $(t) : symlink.ln ] ;
+            self.virtual-targets += $(vt) ;
+            i = [ numbers.increment $(i) ] ;
+        }
+        return $(self.virtual-targets) ;
+    }
+}
+class.class symlink-targets : basic-target ;
+
+# Creates a symbolic link from a set of targets to a set of sources.
+# The targets and sources map one to one. The symlinks generated are
+# limited to be the ones given as the sources. That is, the targets
+# are either padded or trimmed to equate to the sources. The padding
+# is done with the name of the corresponding source. For example::
+#
+#     symlink : one two ;
+#
+# Is equal to::
+#
+#     symlink one two : one two ;
+#
+rule symlink (
+    targets *
+    : sources *
+    )
+{
+    local project = [ CALLER_MODULE ] ;
+    
+    return [ targets.main-target-alternative
+        [ class.new symlink-targets $(project) : $(targets) : $(sources) ] ] ;
+}
+
+rule ln
+{
+    local os ;
+    if [ modules.peek : UNIX ] { os = UNIX ; }
+    else { os ?= [ os.name ] ; }
+    ln-$(os) $(<) : $(>) ;
+}
+
+actions ln-UNIX
+{
+    if test -n '$(<:D)' ; then cd '$(<:D)' ; fi && ln -s '$(>)' '$(<:D=)'
+}
+
+IMPORT $(__name__) : symlink : : symlink ;