Fix Export(), add Import() and Return()

4 files changed, 223 insertions, 75 deletions

diff --git a/src/engine/MANIFEST.in b/src/engine/MANIFEST.in
index c22aebc..ad38b18 100644
--- a/src/engine/MANIFEST.in
+++ b/src/engine/MANIFEST.in
@@ -10,6 +10,7 @@ SCons/Node/FS.py
 SCons/Scanner/__init__.py
 SCons/Scanner/C.py
 SCons/Scanner/Prog.py
+SCons/SConscript.py
 SCons/Script.py
 SCons/Sig/__init__.py
 SCons/Sig/MD5.py
diff --git a/src/engine/SCons/SConscript.py b/src/engine/SCons/SConscript.py
new file mode 100644
index 0000000..1479c7a
--- /dev/null
+++ b/src/engine/SCons/SConscript.py
@@ -0,0 +1,177 @@
+"""engine.SCons.SConscript
+
+This module defines the Python API provided to SConscript and SConstruct 
+files.
+
+"""
+
+#
+# Copyright (c) 2001 Steven Knight
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+#
+
+__revision__ = "src/engine/SCons/SConscript.py __REVISION__ __DATE__ __DEVELOPER__"
+
+import SCons.Errors
+import SCons.Builder
+import SCons.Defaults
+import SCons.Node
+import SCons.Node.FS
+import SCons.Environment
+import string
+import sys
+
+default_targets = []
+help_option = None
+
+# global exports set by Export():
+global_exports = {}
+
+class Frame:
+    """A frame on the SConstruct/SConscript call stack"""
+    def __init__(self, exports):
+        self.globals = BuildDefaultGlobals()
+        self.retval = None 
+        self.prev_dir = SCons.Node.FS.default_fs.getcwd()
+        self.exports = {} # exports from the calling SConscript
+
+        try:
+            if type(exports) == type([]):
+                for export in exports:
+                    self.exports[export] = stack[-1].globals[export]
+            else:
+                for export in string.split(exports):
+                    self.exports[export] = stack[-1].globals[export]
+        except KeyError, x:
+            raise SCons.Errors.UserError, "Export of non-existant variable '%s'"%x
+
+        
+# the SConstruct/SConscript call stack:
+stack = []
+
+# For documentation on the methods in this file, see the scons man-page
+
+def Return(*vars):
+    retval = []
+    try:
+        for var in vars:
+            for v in string.split(var):
+                retval.append(stack[-1].globals[v])
+    except KeyError, x:
+        raise SCons.Errors.UserError, "Return of non-existant variable '%s'"%x
+        
+    if len(retval) == 1:
+        stack[-1].retval = retval[0]
+    else:
+        stack[-1].retval = tuple(retval)
+
+def SConscript(script, exports=[]):
+    retval = ()
+
+    # push:
+    stack.append(Frame(exports))
+
+    # call:
+    if script == "-":
+        exec sys.stdin in stack[-1].globals
+    else:
+        f = SCons.Node.FS.default_fs.File(script)
+        if f.exists():
+            file = open(str(f), "r")
+            SCons.Node.FS.default_fs.chdir(f.dir)
+            exec file in stack[-1].globals
+        else:
+            sys.stderr.write("Ignoring missing SConscript '%s'\n" % f.path)
+    
+
+    # pop:
+    frame = stack.pop()
+    SCons.Node.FS.default_fs.chdir(frame.prev_dir)
+    
+    return frame.retval
+    
+def Default(*targets):
+    for t in targets:
+        if isinstance(t, SCons.Node.Node):
+            default_targets.append(t)
+        else:
+            for s in string.split(t):
+                default_targets.append(s)
+
+def Help(text):
+    global help_option
+    if help_option == 'h':
+        print text
+        print "Use scons -H for help about command-line options."
+        sys.exit(0)
+
+def BuildDir(build_dir, src_dir):
+    SCons.Node.FS.default_fs.BuildDir(build_dir, src_dir)
+
+def GetBuildPath(files):
+    nodes = SCons.Util.scons_str2nodes(files,
+                                       SCons.Node.FS.default_fs.Entry)
+    ret = map(str, nodes)
+    if len(ret) == 1:
+        return ret[0]
+    return ret
+
+def Export(*vars):
+    try:
+        for var in vars:
+            for v in string.split(var):
+                global_exports[v] = stack[-1].globals[v]
+    except KeyError, x:
+        raise SCons.Errors.UserError, "Export of non-existant variable '%s'"%x
+
+def Import(*vars):
+    try:
+        for var in vars:
+            for v in string.split(var):
+                if stack[-1].exports.has_key(v):
+                    stack[-1].globals[v] = stack[-1].exports[v]
+                else:
+                    stack[-1].globals[v] = global_exports[v]
+    except KeyError,x:
+        raise SCons.Errors.UserError, "Import of non-existant variable '%s'"%x
+
+def BuildDefaultGlobals():
+    """
+    Create a dictionary containing all the default globals for 
+    SConscruct and SConscript files.
+    """
+
+    globals = {}
+    globals['Builder'] = SCons.Builder.Builder
+    globals['Environment'] = SCons.Environment.Environment
+    globals['Object'] = SCons.Defaults.Object
+    globals['Program'] = SCons.Defaults.Program
+    globals['Library'] = SCons.Defaults.Library
+    globals['CScan'] = SCons.Defaults.CScan
+    globals['SConscript'] = SConscript
+    globals['Default'] = Default
+    globals['Help'] = Help
+    globals['BuildDir'] = BuildDir
+    globals['GetBuildPath'] = GetBuildPath
+    globals['Export'] = Export
+    globals['Import'] = Import
+    globals['Return'] = Return
+    return globals
diff --git a/src/engine/SCons/SConscriptTests.py b/src/engine/SCons/SConscriptTests.py
new file mode 100644
index 0000000..d44af5c
--- /dev/null
+++ b/src/engine/SCons/SConscriptTests.py
@@ -0,0 +1,28 @@
+#
+# Copyright (c) 2001 Steven Knight
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+ 
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+#
+
+__revision__ = "src/engine/SCons/SConscriptTests.py __REVISION__ __DATE__ __DEVELOPER__"
+
+import SCons.SConscript
+
+# all of the SConscript.py tests are in test/SConscript.py 
diff --git a/src/engine/SCons/Script.py b/src/engine/SCons/Script.py
index 1298a9e..e35e03d 100644
--- a/src/engine/SCons/Script.py
+++ b/src/engine/SCons/Script.py
@@ -58,15 +58,8 @@ from SCons.Errors import *
 import SCons.Sig
 import SCons.Sig.MD5
 from SCons.Taskmaster import Taskmaster
-import SCons.Util
-
-#
-# Modules and classes that we don't use directly in this script, but
-# which we want available for use in SConstruct and SConscript files.
-#
-from SCons.Environment import Environment
-from SCons.Builder import Builder
-from SCons.Defaults import *
+import SCons.Builder
+import SCons.SConscript
 
 
 #
@@ -104,9 +97,7 @@ class CleanTask(SCons.Taskmaster.Task):
 
 # Global variables
 
-default_targets = []
 include_dirs = []
-help_option = None
 num_jobs = 1
 scripts = []
 task_class = BuildTask	# default action is to build targets
@@ -115,6 +106,7 @@ calc = None
 ignore_errors = 0
 keep_going_on_error = 0
 
+
 # utility functions
 
 def _scons_syntax_error(e):
@@ -161,40 +153,6 @@ def _scons_other_errors():
 
 
 
-def SConscript(sconscript, export={}):
-    global scripts
-    scripts.append( (SCons.Node.FS.default_fs.File(sconscript), export) )
-
-def Default(*targets):
-    for t in targets:
-	if isinstance(t, SCons.Node.Node):
-	    default_targets.append(t)
-	else:
-	    for s in string.split(t):
-		default_targets.append(s)
-
-def Help(text):
-    global help_option
-    if help_option == 'h':
-	print text
-	print "Use scons -H for help about command-line options."
-	sys.exit(0)
-
-def BuildDir(build_dir, src_dir):
-    SCons.Node.FS.default_fs.BuildDir(build_dir, src_dir)
-
-def GetBuildPath(files):
-    nodes = SCons.Util.scons_str2nodes(files,
-                                       SCons.Node.FS.default_fs.Entry)
-    ret = map(str, nodes)
-    if len(ret) == 1:
-        return ret[0]
-    return ret
-
-def Export(**kw):
-    # A convenient shorthand to pass exports to the SConscript function.
-    return kw
-
 #
 # After options are initialized, the following variables are
 # filled in:
@@ -392,26 +350,21 @@ def options_init():
 
     def opt_f(opt, arg):
 	global scripts
-	if arg == '-':
-            scripts.append( ( arg, {} ) )
-	else:
-            scripts.append( (SCons.Node.FS.default_fs.File(arg), {}) )
+        scripts.append(arg)
 
     Option(func = opt_f,
 	short = 'f', long = ['file', 'makefile', 'sconstruct'], arg = 'FILE',
 	help = "Read FILE as the top-level SConstruct file.")
 
     def opt_help(opt, arg):
-	global help_option
-	help_option = 'h'
+        SCons.SConscript.help_option = 'h'
 
     Option(func = opt_help,
 	short = 'h', long = ['help'],
 	help = "Print defined help message, or this one.")
 
     def opt_help_options(opt, arg):
-	global help_option
-	help_option = 'H'
+        SCons.SConscript.help_option = 'H'
 
     Option(func = opt_help_options,
 	short = 'H', long = ['help-options'],
@@ -584,7 +537,7 @@ def UsageString():
 
 
 def _main():
-    global scripts, help_option, num_jobs, task_class, calc
+    global scripts, num_jobs, task_class, calc
 
     targets = []
 
@@ -618,18 +571,18 @@ def _main():
     if not scripts:
         for file in ['SConstruct', 'Sconstruct', 'sconstruct']:
             if os.path.isfile(file):
-                scripts.append( (SCons.Node.FS.default_fs.File(file), {}) )
+                scripts.append(file)
                 break
 
-    if help_option == 'H':
+    if SCons.SConscript.help_option == 'H':
 	print UsageString()
 	sys.exit(0)
 
     if not scripts:
-	if help_option == 'h':
-	    # There's no SConstruct, but they specified either -h or
-	    # -H.  Give them the options usage now, before we fail
-	    # trying to read a non-existent SConstruct file.
+        if SCons.SConscript.help_option == 'h':
+            # There's no SConstruct, but they specified -h.
+            # Give them the options usage now, before we fail
+            # trying to read a non-existent SConstruct file.
 	    print UsageString()
 	    sys.exit(0)
 	else:
@@ -637,30 +590,19 @@ def _main():
 
     sys.path = include_dirs + sys.path
 
-    while scripts:
-        f, exports = scripts.pop(0)
-        script_env = copy.copy(globals())
-        script_env.update(exports)
-        if f == "-":
-            exec sys.stdin in script_env
-	else:
-            if f.exists():
-                file = open(str(f), "r")
-                SCons.Node.FS.default_fs.chdir(f.dir)
-                exec file in script_env
-            else:
-                sys.stderr.write("Ignoring missing SConscript '%s'\n" % f.path)
+    for script in scripts:
+        SCons.SConscript.SConscript(script)
 
     SCons.Node.FS.default_fs.chdir(SCons.Node.FS.default_fs.Top)
 
-    if help_option == 'h':
+    if SCons.SConscript.help_option == 'h':
 	# They specified -h, but there was no Help() inside the
 	# SConscript files.  Give them the options usage.
 	print UsageString()
 	sys.exit(0)
 
     if not targets:
-	targets = default_targets
+        targets = SCons.SConscript.default_targets
 	
     def Entry(x):
 	if isinstance(x, SCons.Node.Node):