Fixes AcademySoftwareFoundation#694 and lets cmd and powershell pass …

…all shell tests.

This implements ${VAR} and $VAR variables for cmd and Powershell like, as
well as their native forms like %VAR% and $Env:VAR.
In order to handle the ambiguity of variables in the form of $Env:Literal
in Unix and Windows the NamespaceFormatter may take interpreter regex into
account that is being supplied by the underlying shell.

For command execution on Windows .PY is being added to the PATHEXT and
the create_script function is extended to create any form of execution
script. This behaviour can be controlled via a rezconfig, but defaults to
backwards compatible Unix-only behaviour.

src/rez/bind/hello_world.py

@@ -10,7 +10,7 @@
 from rez.package_maker__ import make_package
 from rez.vendor.version.version import Version
 from rez.utils.lint_helper import env
-from rez.util import create_executable_script
+from rez.util import create_executable_script, ExecutableScriptMode
 from rez.bind._utils import make_dirs, check_version
 import os.path
 
@@ -26,10 +26,10 @@ def hello_world_source():
 
     p = OptionParser()
     p.add_option("-q", dest="quiet", action="store_true",
-        help="quiet mode")
+                 help="quiet mode")
     p.add_option("-r", dest="retcode", type="int", default=0,
-        help="exit with a non-zero return code")
-    opts,args = p.parse_args()
+                 help="exit with a non-zero return code")
+    opts, args = p.parse_args()
 
     if not opts.quiet:
         print("Hello Rez World!")
@@ -43,7 +43,15 @@ def bind(path, version_range=None, opts=None, parser=None):
     def make_root(variant, root):
         binpath = make_dirs(root, "bin")
         filepath = os.path.join(binpath, "hello_world")
-        create_executable_script(filepath, hello_world_source)
+
+        # In order for this script to run on each platform we create the
+        # platform-specific script. This also requires the additional_pathext
+        # setting of the windows shell plugins to include ".PY"
+        create_executable_script(
+            filepath,
+            hello_world_source,
+            py_script_mode=ExecutableScriptMode.platform_specific
+        )
 
     with make_package("hello_world", path, make_root=make_root) as pkg:
         pkg.version = version
@@ -52,7 +60,6 @@ def make_root(variant, root):
 
     return pkg.installed_variants
 
-
 # Copyright 2013-2016 Allan Johns.
 #
 # This library is free software: you can redistribute it and/or

src/rez/config.py

@@ -234,6 +234,13 @@ def schema(cls):
         return Or(*(x.name for x in RezToolsVisibility))
 
 
+class ExecutableScriptMode_(Str):
+    @cached_class_property
+    def schema(cls):
+        from rez.util import ExecutableScriptMode
+        return Or(*(x.name for x in ExecutableScriptMode))
+
+
 class OptionalStrOrFunction(Setting):
     schema = Or(None, basestring, callable)
 
@@ -303,6 +310,7 @@ def _parse_env_var(self, value):
     "documentation_url":                            Str,
     "suite_visibility":                             SuiteVisibility_,
     "rez_tools_visibility":                         RezToolsVisibility_,
+    "create_executable_script_mode":                ExecutableScriptMode_,
     "suite_alias_prefix_char":                      Char,
     "package_definition_python_path":               OptionalStr,
     "tmpdir":                                       OptionalStr,

src/rez/rex.py

@@ -443,6 +443,17 @@ class ActionInterpreter(object):
     """
     expand_env_vars = False
 
+    # RegEx that captures environment variables (generic form).
+    # Extend/Override to regex formats that can captured environment formats
+    # in other interpreters like shells if needed
+    ENV_VAR_REGEX = re.compile(
+        "|".join([
+            "\\${([^\\{\\}]+?)}",               # ${ENVVAR}
+            "\\$([a-zA-Z_]+[a-zA-Z0-9_]*?)",    # $ENVVAR
+        ])
+    )
+
+
     def get_output(self, style=OutputStyle.file):
         """Returns any implementation specific data.
 
@@ -874,12 +885,6 @@ class NamespaceFormatter(Formatter):
     across shells, and avoids some problems with non-curly-braced variables in
     some situations.
     """
-    # Note: the regex used here matches more than just posix environment variable
-    # names, because special shell expansion characters may be present.
-    ENV_VAR_REF_1   = "\\${([^\\{\\}]+?)}"  # ${ENVVAR}
-    ENV_VAR_REF_2   = "\\$([a-zA-Z_]+[a-zA-Z0-9_]*?)"  # $ENVVAR
-    ENV_VAR_REF     = "%s|%s" % (ENV_VAR_REF_1, ENV_VAR_REF_2)
-    ENV_VAR_REGEX   = re.compile(ENV_VAR_REF)
 
     def __init__(self, namespace):
         Formatter.__init__(self)
@@ -891,7 +896,11 @@ def escape_envvar(matchobj):
             value = (x for x in matchobj.groups() if x is not None).next()
             return "${{%s}}" % value
 
-        format_string_ = re.sub(self.ENV_VAR_REGEX, escape_envvar, format_string)
+        regex = ActionInterpreter.ENV_VAR_REGEX
+        if "regex" in kwargs:
+            regex = kwargs["regex"]
+
+        format_string_ = re.sub(regex, escape_envvar, format_string)
 
         # for recursive formatting, where a field has a value we want to expand,
         # add kwargs to namespace, so format_field can use them...
@@ -1251,7 +1260,7 @@ def get_output(self, style=OutputStyle.file):
         return self.manager.get_output(style=style)
 
     def expand(self, value):
-        return self.formatter.format(str(value))
+        return self.formatter.format(str(value), regex=self.interpreter.ENV_VAR_REGEX)
 
 
 # Copyright 2013-2016 Allan Johns.

src/rez/rezconfig.py

@@ -619,6 +619,29 @@
 suite_alias_prefix_char = "+"
 
 
+###############################################################################
+# Utils
+###############################################################################
+
+# Default option on how to create scripts with util.create_executable_script.
+# In order to support both windows and other OS it is recommended to set this
+# to 'both'.
+#
+# Possible modes:
+# - requested:
+#       Requested shebang script only. Usually extension-less.
+# - py:
+#       Create .py script that will allow launching scripts on windows,
+#       if the shell adds .py to PATHEXT. Make sure to use PEP-397 py.exe
+#       as default application for .py files.
+# - platform_specific:
+#       Will create py script on windows and requested on other platforms
+# - both:
+#       Creates the requested file and a .py script so that scripts can be
+#       launched without extension from windows and other systems.
+create_executable_script_mode = "requested"
+
+
 ###############################################################################
 # Appearance
 ###############################################################################

src/rez/shells.py

@@ -14,6 +14,7 @@
 import os
 import os.path
 import pipes
+import re
 
 
 def get_shell_types():
@@ -38,7 +39,6 @@ def create_shell(shell=None, **kwargs):
 class Shell(ActionInterpreter):
     """Class representing a shell, such as bash or tcsh.
     """
-
     schema_dict = {
         "prompt": basestring}
 
@@ -160,6 +160,29 @@ def spawn_shell(self, context_file, tmpdir, rcfile=None, norc=False,
         """
         raise NotImplementedError
 
+    @classmethod
+    def get_key_token(cls, key, form=0):
+        """
+        Encodes the environment variable into the shell specific form.
+        Shells might implement multiple forms, but the most common/safest
+        should be implemented as form 0 or if the form exceeds key_form_count.
+
+        Args:
+            key: Variable name to encode
+            form: number of token form
+
+        Returns:
+            str of encoded token form
+        """
+        raise NotImplementedError
+
+    @classmethod
+    def key_form_count(cls):
+        """
+        Returns: Number of forms get_key_token supports
+        """
+        raise NotImplementedError
+
     def join(self, command):
         """
         Args:
@@ -171,6 +194,7 @@ def join(self, command):
         """
         raise NotImplementedError
 
+
 class UnixShell(Shell):
     """
     A base class for common *nix shells, such as bash and tcsh.
@@ -396,8 +420,16 @@ def comment(self, value):
     def shebang(self):
         self._addline("#!%s" % self.executable)
 
-    def get_key_token(self, key):
-        return "${%s}" % key
+    @classmethod
+    def get_key_token(cls, key, form=0):
+        if form == 1:
+            return "$%s" % key
+        else:
+            return "${%s}" % key
+
+    @classmethod
+    def key_form_count(cls):
+        return 2
 
     def join(self, command):
         return shlex_join(command)