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Editing: codegen.py
# mako/codegen.py # Copyright 2006-2022 the Mako authors and contributors <see AUTHORS file> # # This module is part of Mako and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php """provides functionality for rendering a parsetree constructing into module source code.""" import json import re import time from mako import ast from mako import exceptions from mako import filters from mako import parsetree from mako import util from mako.pygen import PythonPrinter MAGIC_NUMBER = 10 # names which are hardwired into the # template and are not accessed via the # context itself TOPLEVEL_DECLARED = {"UNDEFINED", "STOP_RENDERING"} RESERVED_NAMES = {"context", "loop"}.union(TOPLEVEL_DECLARED) def compile( # noqa node, uri, filename=None, default_filters=None, buffer_filters=None, imports=None, future_imports=None, source_encoding=None, generate_magic_comment=True, strict_undefined=False, enable_loop=True, reserved_names=frozenset(), ): """Generate module source code given a parsetree node, uri, and optional source filename""" buf = util.FastEncodingBuffer() printer = PythonPrinter(buf) _GenerateRenderMethod( printer, _CompileContext( uri, filename, default_filters, buffer_filters, imports, future_imports, source_encoding, generate_magic_comment, strict_undefined, enable_loop, reserved_names, ), node, ) return buf.getvalue() class _CompileContext: def __init__( self, uri, filename, default_filters, buffer_filters, imports, future_imports, source_encoding, generate_magic_comment, strict_undefined, enable_loop, reserved_names, ): self.uri = uri self.filename = filename self.default_filters = default_filters self.buffer_filters = buffer_filters self.imports = imports self.future_imports = future_imports self.source_encoding = source_encoding self.generate_magic_comment = generate_magic_comment self.strict_undefined = strict_undefined self.enable_loop = enable_loop self.reserved_names = reserved_names class _GenerateRenderMethod: """A template visitor object which generates the full module source for a template. """ def __init__(self, printer, compiler, node): self.printer = printer self.compiler = compiler self.node = node self.identifier_stack = [None] self.in_def = isinstance(node, (parsetree.DefTag, parsetree.BlockTag)) if self.in_def: name = "render_%s" % node.funcname args = node.get_argument_expressions() filtered = len(node.filter_args.args) > 0 buffered = eval(node.attributes.get("buffered", "False")) cached = eval(node.attributes.get("cached", "False")) defs = None pagetag = None if node.is_block and not node.is_anonymous: args += ["**pageargs"] else: defs = self.write_toplevel() pagetag = self.compiler.pagetag name = "render_body" if pagetag is not None: args = pagetag.body_decl.get_argument_expressions() if not pagetag.body_decl.kwargs: args += ["**pageargs"] cached = eval(pagetag.attributes.get("cached", "False")) self.compiler.enable_loop = self.compiler.enable_loop or eval( pagetag.attributes.get("enable_loop", "False") ) else: args = ["**pageargs"] cached = False buffered = filtered = False if args is None: args = ["context"] else: args = [a for a in ["context"] + args] self.write_render_callable( pagetag or node, name, args, buffered, filtered, cached ) if defs is not None: for node in defs: _GenerateRenderMethod(printer, compiler, node) if not self.in_def: self.write_metadata_struct() def write_metadata_struct(self): self.printer.source_map[self.printer.lineno] = max( self.printer.source_map ) struct = { "filename": self.compiler.filename, "uri": self.compiler.uri, "source_encoding": self.compiler.source_encoding, "line_map": self.printer.source_map, } self.printer.writelines( '"""', "__M_BEGIN_METADATA", json.dumps(struct), "__M_END_METADATA\n" '"""', ) @property def identifiers(self): return self.identifier_stack[-1] def write_toplevel(self): """Traverse a template structure for module-level directives and generate the start of module-level code. """ inherit = [] namespaces = {} module_code = [] self.compiler.pagetag = None class FindTopLevel: def visitInheritTag(s, node): inherit.append(node) def visitNamespaceTag(s, node): namespaces[node.name] = node def visitPageTag(s, node): self.compiler.pagetag = node def visitCode(s, node): if node.ismodule: module_code.append(node) f = FindTopLevel() for n in self.node.nodes: n.accept_visitor(f) self.compiler.namespaces = namespaces module_ident = set() for n in module_code: module_ident = module_ident.union(n.declared_identifiers()) module_identifiers = _Identifiers(self.compiler) module_identifiers.declared = module_ident # module-level names, python code if ( self.compiler.generate_magic_comment and self.compiler.source_encoding ): self.printer.writeline( "# -*- coding:%s -*-" % self.compiler.source_encoding ) if self.compiler.future_imports: self.printer.writeline( "from __future__ import %s" % (", ".join(self.compiler.future_imports),) ) self.printer.writeline("from mako import runtime, filters, cache") self.printer.writeline("UNDEFINED = runtime.UNDEFINED") self.printer.writeline("STOP_RENDERING = runtime.STOP_RENDERING") self.printer.writeline("__M_dict_builtin = dict") self.printer.writeline("__M_locals_builtin = locals") self.printer.writeline("_magic_number = %r" % MAGIC_NUMBER) self.printer.writeline("_modified_time = %r" % time.time()) self.printer.writeline("_enable_loop = %r" % self.compiler.enable_loop) self.printer.writeline( "_template_filename = %r" % self.compiler.filename ) self.printer.writeline("_template_uri = %r" % self.compiler.uri) self.printer.writeline( "_source_encoding = %r" % self.compiler.source_encoding ) if self.compiler.imports: buf = "" for imp in self.compiler.imports: buf += imp + "\n" self.printer.writeline(imp) impcode = ast.PythonCode( buf, source="", lineno=0, pos=0, filename="template defined imports", ) else: impcode = None main_identifiers = module_identifiers.branch(self.node) mit = module_identifiers.topleveldefs module_identifiers.topleveldefs = mit.union( main_identifiers.topleveldefs ) module_identifiers.declared.update(TOPLEVEL_DECLARED) if impcode: module_identifiers.declared.update(impcode.declared_identifiers) self.compiler.identifiers = module_identifiers self.printer.writeline( "_exports = %r" % [n.name for n in main_identifiers.topleveldefs.values()] ) self.printer.write_blanks(2) if len(module_code): self.write_module_code(module_code) if len(inherit): self.write_namespaces(namespaces) self.write_inherit(inherit[-1]) elif len(namespaces): self.write_namespaces(namespaces) return list(main_identifiers.topleveldefs.values()) def write_render_callable( self, node, name, args, buffered, filtered, cached ): """write a top-level render callable. this could be the main render() method or that of a top-level def.""" if self.in_def: decorator = node.decorator if decorator: self.printer.writeline( "@runtime._decorate_toplevel(%s)" % decorator ) self.printer.start_source(node.lineno) self.printer.writelines( "def %s(%s):" % (name, ",".join(args)), # push new frame, assign current frame to __M_caller "__M_caller = context.caller_stack._push_frame()", "try:", ) if buffered or filtered or cached: self.printer.writeline("context._push_buffer()") self.identifier_stack.append( self.compiler.identifiers.branch(self.node) ) if (not self.in_def or self.node.is_block) and "**pageargs" in args: self.identifier_stack[-1].argument_declared.add("pageargs") if not self.in_def and ( len(self.identifiers.locally_assigned) > 0 or len(self.identifiers.argument_declared) > 0 ): self.printer.writeline( "__M_locals = __M_dict_builtin(%s)" % ",".join( [ "%s=%s" % (x, x) for x in self.identifiers.argument_declared ] ) ) self.write_variable_declares(self.identifiers, toplevel=True) for n in self.node.nodes: n.accept_visitor(self) self.write_def_finish(self.node, buffered, filtered, cached) self.printer.writeline(None) self.printer.write_blanks(2) if cached: self.write_cache_decorator( node, name, args, buffered, self.identifiers, toplevel=True ) def write_module_code(self, module_code): """write module-level template code, i.e. that which is enclosed in <%! %> tags in the template.""" for n in module_code: self.printer.write_indented_block(n.text, starting_lineno=n.lineno) def write_inherit(self, node): """write the module-level inheritance-determination callable.""" self.printer.writelines( "def _mako_inherit(template, context):", "_mako_generate_namespaces(context)", "return runtime._inherit_from(context, %s, _template_uri)" % (node.parsed_attributes["file"]), None, ) def write_namespaces(self, namespaces): """write the module-level namespace-generating callable.""" self.printer.writelines( "def _mako_get_namespace(context, name):", "try:", "return context.namespaces[(__name__, name)]", "except KeyError:", "_mako_generate_namespaces(context)", "return context.namespaces[(__name__, name)]", None, None, ) self.printer.writeline("def _mako_generate_namespaces(context):") for node in namespaces.values(): if "import" in node.attributes: self.compiler.has_ns_imports = True self.printer.start_source(node.lineno) if len(node.nodes): self.printer.writeline("def make_namespace():") export = [] identifiers = self.compiler.identifiers.branch(node) self.in_def = True class NSDefVisitor: def visitDefTag(s, node): s.visitDefOrBase(node) def visitBlockTag(s, node): s.visitDefOrBase(node) def visitDefOrBase(s, node): if node.is_anonymous: raise exceptions.CompileException( "Can't put anonymous blocks inside " "<%namespace>", **node.exception_kwargs, ) self.write_inline_def(node, identifiers, nested=False) export.append(node.funcname) vis = NSDefVisitor() for n in node.nodes: n.accept_visitor(vis) self.printer.writeline("return [%s]" % (",".join(export))) self.printer.writeline(None) self.in_def = False callable_name = "make_namespace()" else: callable_name = "None" if "file" in node.parsed_attributes: self.printer.writeline( "ns = runtime.TemplateNamespace(%r," " context._clean_inheritance_tokens()," " templateuri=%s, callables=%s, " " calling_uri=_template_uri)" % ( node.name, node.parsed_attributes.get("file", "None"), callable_name, ) ) elif "module" in node.parsed_attributes: self.printer.writeline( "ns = runtime.ModuleNamespace(%r," " context._clean_inheritance_tokens()," " callables=%s, calling_uri=_template_uri," " module=%s)" % ( node.name, callable_name, node.parsed_attributes.get("module", "None"), ) ) else: self.printer.writeline( "ns = runtime.Namespace(%r," " context._clean_inheritance_tokens()," " callables=%s, calling_uri=_template_uri)" % (node.name, callable_name) ) if eval(node.attributes.get("inheritable", "False")): self.printer.writeline("context['self'].%s = ns" % (node.name)) self.printer.writeline( "context.namespaces[(__name__, %s)] = ns" % repr(node.name) ) self.printer.write_blanks(1) if not len(namespaces): self.printer.writeline("pass") self.printer.writeline(None) def write_variable_declares(self, identifiers, toplevel=False, limit=None): """write variable declarations at the top of a function. the variable declarations are in the form of callable definitions for defs and/or name lookup within the function's context argument. the names declared are based on the names that are referenced in the function body, which don't otherwise have any explicit assignment operation. names that are assigned within the body are assumed to be locally-scoped variables and are not separately declared. for def callable definitions, if the def is a top-level callable then a 'stub' callable is generated which wraps the current Context into a closure. if the def is not top-level, it is fully rendered as a local closure. """ # collection of all defs available to us in this scope comp_idents = {c.funcname: c for c in identifiers.defs} to_write = set() # write "context.get()" for all variables we are going to # need that arent in the namespace yet to_write = to_write.union(identifiers.undeclared) # write closure functions for closures that we define # right here to_write = to_write.union( [c.funcname for c in identifiers.closuredefs.values()] ) # remove identifiers that are declared in the argument # signature of the callable to_write = to_write.difference(identifiers.argument_declared) # remove identifiers that we are going to assign to. # in this way we mimic Python's behavior, # i.e. assignment to a variable within a block # means that variable is now a "locally declared" var, # which cannot be referenced beforehand. to_write = to_write.difference(identifiers.locally_declared) if self.compiler.enable_loop: has_loop = "loop" in to_write to_write.discard("loop") else: has_loop = False # if a limiting set was sent, constraint to those items in that list # (this is used for the caching decorator) if limit is not None: to_write = to_write.intersection(limit) if toplevel and getattr(self.compiler, "has_ns_imports", False): self.printer.writeline("_import_ns = {}") self.compiler.has_imports = True for ident, ns in self.compiler.namespaces.items(): if "import" in ns.attributes: self.printer.writeline( "_mako_get_namespace(context, %r)." "_populate(_import_ns, %r)" % ( ident, re.split(r"\s*,\s*", ns.attributes["import"]), ) ) if has_loop: self.printer.writeline("loop = __M_loop = runtime.LoopStack()") for ident in to_write: if ident in comp_idents: comp = comp_idents[ident] if comp.is_block: if not comp.is_anonymous: self.write_def_decl(comp, identifiers) else: self.write_inline_def(comp, identifiers, nested=True) else: if comp.is_root(): self.write_def_decl(comp, identifiers) else: self.write_inline_def(comp, identifiers, nested=True) elif ident in self.compiler.namespaces: self.printer.writeline( "%s = _mako_get_namespace(context, %r)" % (ident, ident) ) else: if getattr(self.compiler, "has_ns_imports", False): if self.compiler.strict_undefined: self.printer.writelines( "%s = _import_ns.get(%r, UNDEFINED)" % (ident, ident), "if %s is UNDEFINED:" % ident, "try:", "%s = context[%r]" % (ident, ident), "except KeyError:", "raise NameError(\"'%s' is not defined\")" % ident, None, None, ) else: self.printer.writeline( "%s = _import_ns.get" "(%r, context.get(%r, UNDEFINED))" % (ident, ident, ident) ) else: if self.compiler.strict_undefined: self.printer.writelines( "try:", "%s = context[%r]" % (ident, ident), "except KeyError:", "raise NameError(\"'%s' is not defined\")" % ident, None, ) else: self.printer.writeline( "%s = context.get(%r, UNDEFINED)" % (ident, ident) ) self.printer.writeline("__M_writer = context.writer()") def write_def_decl(self, node, identifiers): """write a locally-available callable referencing a top-level def""" funcname = node.funcname namedecls = node.get_argument_expressions() nameargs = node.get_argument_expressions(as_call=True) if not self.in_def and ( len(self.identifiers.locally_assigned) > 0 or len(self.identifiers.argument_declared) > 0 ): nameargs.insert(0, "context._locals(__M_locals)") else: nameargs.insert(0, "context") self.printer.writeline("def %s(%s):" % (funcname, ",".join(namedecls))) self.printer.writeline( "return render_%s(%s)" % (funcname, ",".join(nameargs)) ) self.printer.writeline(None) def write_inline_def(self, node, identifiers, nested): """write a locally-available def callable inside an enclosing def.""" namedecls = node.get_argument_expressions() decorator = node.decorator if decorator: self.printer.writeline( "@runtime._decorate_inline(context, %s)" % decorator ) self.printer.writeline( "def %s(%s):" % (node.funcname, ",".join(namedecls)) ) filtered = len(node.filter_args.args) > 0 buffered = eval(node.attributes.get("buffered", "False")) cached = eval(node.attributes.get("cached", "False")) self.printer.writelines( # push new frame, assign current frame to __M_caller "__M_caller = context.caller_stack._push_frame()", "try:", ) if buffered or filtered or cached: self.printer.writelines("context._push_buffer()") identifiers = identifiers.branch(node, nested=nested) self.write_variable_declares(identifiers) self.identifier_stack.append(identifiers) for n in node.nodes: n.accept_visitor(self) self.identifier_stack.pop() self.write_def_finish(node, buffered, filtered, cached) self.printer.writeline(None) if cached: self.write_cache_decorator( node, node.funcname, namedecls, False, identifiers, inline=True, toplevel=False, ) def write_def_finish( self, node, buffered, filtered, cached, callstack=True ): """write the end section of a rendering function, either outermost or inline. this takes into account if the rendering function was filtered, buffered, etc. and closes the corresponding try: block if any, and writes code to retrieve captured content, apply filters, send proper return value.""" if not buffered and not cached and not filtered: self.printer.writeline("return ''") if callstack: self.printer.writelines( "finally:", "context.caller_stack._pop_frame()", None ) if buffered or filtered or cached: if buffered or cached: # in a caching scenario, don't try to get a writer # from the context after popping; assume the caching # implemenation might be using a context with no # extra buffers self.printer.writelines( "finally:", "__M_buf = context._pop_buffer()" ) else: self.printer.writelines( "finally:", "__M_buf, __M_writer = context._pop_buffer_and_writer()", ) if callstack: self.printer.writeline("context.caller_stack._pop_frame()") s = "__M_buf.getvalue()" if filtered: s = self.create_filter_callable( node.filter_args.args, s, False ) self.printer.writeline(None) if buffered and not cached: s = self.create_filter_callable( self.compiler.buffer_filters, s, False ) if buffered or cached: self.printer.writeline("return %s" % s) else: self.printer.writelines("__M_writer(%s)" % s, "return ''") def write_cache_decorator( self, node_or_pagetag, name, args, buffered, identifiers, inline=False, toplevel=False, ): """write a post-function decorator to replace a rendering callable with a cached version of itself.""" self.printer.writeline("__M_%s = %s" % (name, name)) cachekey = node_or_pagetag.parsed_attributes.get( "cache_key", repr(name) ) cache_args = {} if self.compiler.pagetag is not None: cache_args.update( (pa[6:], self.compiler.pagetag.parsed_attributes[pa]) for pa in self.compiler.pagetag.parsed_attributes if pa.startswith("cache_") and pa != "cache_key" ) cache_args.update( (pa[6:], node_or_pagetag.parsed_attributes[pa]) for pa in node_or_pagetag.parsed_attributes if pa.startswith("cache_") and pa != "cache_key" ) if "timeout" in cache_args: cache_args["timeout"] = int(eval(cache_args["timeout"])) self.printer.writeline("def %s(%s):" % (name, ",".join(args))) # form "arg1, arg2, arg3=arg3, arg4=arg4", etc. pass_args = [ "%s=%s" % ((a.split("=")[0],) * 2) if "=" in a else a for a in args ] self.write_variable_declares( identifiers, toplevel=toplevel, limit=node_or_pagetag.undeclared_identifiers(), ) if buffered: s = ( "context.get('local')." "cache._ctx_get_or_create(" "%s, lambda:__M_%s(%s), context, %s__M_defname=%r)" % ( cachekey, name, ",".join(pass_args), "".join( ["%s=%s, " % (k, v) for k, v in cache_args.items()] ), name, ) ) # apply buffer_filters s = self.create_filter_callable( self.compiler.buffer_filters, s, False ) self.printer.writelines("return " + s, None) else: self.printer.writelines( "__M_writer(context.get('local')." "cache._ctx_get_or_create(" "%s, lambda:__M_%s(%s), context, %s__M_defname=%r))" % ( cachekey, name, ",".join(pass_args), "".join( ["%s=%s, " % (k, v) for k, v in cache_args.items()] ), name, ), "return ''", None, ) def create_filter_callable(self, args, target, is_expression): """write a filter-applying expression based on the filters present in the given filter names, adjusting for the global 'default' filter aliases as needed.""" def locate_encode(name): if re.match(r"decode\..+", name): return "filters." + name else: return filters.DEFAULT_ESCAPES.get(name, name) if "n" not in args: if is_expression: if self.compiler.pagetag: args = self.compiler.pagetag.filter_args.args + args if self.compiler.default_filters and "n" not in args: args = self.compiler.default_filters + args for e in args: # if filter given as a function, get just the identifier portion if e == "n": continue m = re.match(r"(.+?)(\(.*\))", e) if m: ident, fargs = m.group(1, 2) f = locate_encode(ident) e = f + fargs else: e = locate_encode(e) assert e is not None target = "%s(%s)" % (e, target) return target def visitExpression(self, node): self.printer.start_source(node.lineno) if ( len(node.escapes) or ( self.compiler.pagetag is not None and len(self.compiler.pagetag.filter_args.args) ) or len(self.compiler.default_filters) ): s = self.create_filter_callable( node.escapes_code.args, "%s" % node.text, True ) self.printer.writeline("__M_writer(%s)" % s) else: self.printer.writeline("__M_writer(%s)" % node.text) def visitControlLine(self, node): if node.isend: self.printer.writeline(None) if node.has_loop_context: self.printer.writeline("finally:") self.printer.writeline("loop = __M_loop._exit()") self.printer.writeline(None) else: self.printer.start_source(node.lineno) if self.compiler.enable_loop and node.keyword == "for": text = mangle_mako_loop(node, self.printer) else: text = node.text self.printer.writeline(text) children = node.get_children() # this covers the three situations where we want to insert a pass: # 1) a ternary control line with no children, # 2) a primary control line with nothing but its own ternary # and end control lines, and # 3) any control line with no content other than comments if not children or ( all( isinstance(c, (parsetree.Comment, parsetree.ControlLine)) for c in children ) and all( (node.is_ternary(c.keyword) or c.isend) for c in children if isinstance(c, parsetree.ControlLine) ) ): self.printer.writeline("pass") def visitText(self, node): self.printer.start_source(node.lineno) self.printer.writeline("__M_writer(%s)" % repr(node.content)) def visitTextTag(self, node): filtered = len(node.filter_args.args) > 0 if filtered: self.printer.writelines( "__M_writer = context._push_writer()", "try:" ) for n in node.nodes: n.accept_visitor(self) if filtered: self.printer.writelines( "finally:", "__M_buf, __M_writer = context._pop_buffer_and_writer()", "__M_writer(%s)" % self.create_filter_callable( node.filter_args.args, "__M_buf.getvalue()", False ), None, ) def visitCode(self, node): if not node.ismodule: self.printer.write_indented_block( node.text, starting_lineno=node.lineno ) if not self.in_def and len(self.identifiers.locally_assigned) > 0: # if we are the "template" def, fudge locally # declared/modified variables into the "__M_locals" dictionary, # which is used for def calls within the same template, # to simulate "enclosing scope" self.printer.writeline( "__M_locals_builtin_stored = __M_locals_builtin()" ) self.printer.writeline( "__M_locals.update(__M_dict_builtin([(__M_key," " __M_locals_builtin_stored[__M_key]) for __M_key in" " [%s] if __M_key in __M_locals_builtin_stored]))" % ",".join([repr(x) for x in node.declared_identifiers()]) ) def visitIncludeTag(self, node): self.printer.start_source(node.lineno) args = node.attributes.get("args") if args: self.printer.writeline( "runtime._include_file(context, %s, _template_uri, %s)" % (node.parsed_attributes["file"], args) ) else: self.printer.writeline( "runtime._include_file(context, %s, _template_uri)" % (node.parsed_attributes["file"]) ) def visitNamespaceTag(self, node): pass def visitDefTag(self, node): pass def visitBlockTag(self, node): if node.is_anonymous: self.printer.writeline("%s()" % node.funcname) else: nameargs = node.get_argument_expressions(as_call=True) nameargs += ["**pageargs"] self.printer.writeline( "if 'parent' not in context._data or " "not hasattr(context._data['parent'], '%s'):" % node.funcname ) self.printer.writeline( "context['self'].%s(%s)" % (node.funcname, ",".join(nameargs)) ) self.printer.writeline("\n") def visitCallNamespaceTag(self, node): # TODO: we can put namespace-specific checks here, such # as ensure the given namespace will be imported, # pre-import the namespace, etc. self.visitCallTag(node) def visitCallTag(self, node): self.printer.writeline("def ccall(caller):") export = ["body"] callable_identifiers = self.identifiers.branch(node, nested=True) body_identifiers = callable_identifiers.branch(node, nested=False) # we want the 'caller' passed to ccall to be used # for the body() function, but for other non-body() # <%def>s within <%call> we want the current caller # off the call stack (if any) body_identifiers.add_declared("caller") self.identifier_stack.append(body_identifiers) class DefVisitor: def visitDefTag(s, node): s.visitDefOrBase(node) def visitBlockTag(s, node): s.visitDefOrBase(node) def visitDefOrBase(s, node): self.write_inline_def(node, callable_identifiers, nested=False) if not node.is_anonymous: export.append(node.funcname) # remove defs that are within the <%call> from the # "closuredefs" defined in the body, so they dont render twice if node.funcname in body_identifiers.closuredefs: del body_identifiers.closuredefs[node.funcname] vis = DefVisitor() for n in node.nodes: n.accept_visitor(vis) self.identifier_stack.pop() bodyargs = node.body_decl.get_argument_expressions() self.printer.writeline("def body(%s):" % ",".join(bodyargs)) # TODO: figure out best way to specify # buffering/nonbuffering (at call time would be better) buffered = False if buffered: self.printer.writelines("context._push_buffer()", "try:") self.write_variable_declares(body_identifiers) self.identifier_stack.append(body_identifiers) for n in node.nodes: n.accept_visitor(self) self.identifier_stack.pop() self.write_def_finish(node, buffered, False, False, callstack=False) self.printer.writelines(None, "return [%s]" % (",".join(export)), None) self.printer.writelines( # push on caller for nested call "context.caller_stack.nextcaller = " "runtime.Namespace('caller', context, " "callables=ccall(__M_caller))", "try:", ) self.printer.start_source(node.lineno) self.printer.writelines( "__M_writer(%s)" % self.create_filter_callable([], node.expression, True), "finally:", "context.caller_stack.nextcaller = None", None, ) class _Identifiers: """tracks the status of identifier names as template code is rendered.""" def __init__(self, compiler, node=None, parent=None, nested=False): if parent is not None: # if we are the branch created in write_namespaces(), # we don't share any context from the main body(). if isinstance(node, parsetree.NamespaceTag): self.declared = set() self.topleveldefs = util.SetLikeDict() else: # things that have already been declared # in an enclosing namespace (i.e. names we can just use) self.declared = ( set(parent.declared) .union([c.name for c in parent.closuredefs.values()]) .union(parent.locally_declared) .union(parent.argument_declared) ) # if these identifiers correspond to a "nested" # scope, it means whatever the parent identifiers # had as undeclared will have been declared by that parent, # and therefore we have them in our scope. if nested: self.declared = self.declared.union(parent.undeclared) # top level defs that are available self.topleveldefs = util.SetLikeDict(**parent.topleveldefs) else: self.declared = set() self.topleveldefs = util.SetLikeDict() self.compiler = compiler # things within this level that are referenced before they # are declared (e.g. assigned to) self.undeclared = set() # things that are declared locally. some of these things # could be in the "undeclared" list as well if they are # referenced before declared self.locally_declared = set() # assignments made in explicit python blocks. # these will be propagated to # the context of local def calls. self.locally_assigned = set() # things that are declared in the argument # signature of the def callable self.argument_declared = set() # closure defs that are defined in this level self.closuredefs = util.SetLikeDict() self.node = node if node is not None: node.accept_visitor(self) illegal_names = self.compiler.reserved_names.intersection( self.locally_declared ) if illegal_names: raise exceptions.NameConflictError( "Reserved words declared in template: %s" % ", ".join(illegal_names) ) def branch(self, node, **kwargs): """create a new Identifiers for a new Node, with this Identifiers as the parent.""" return _Identifiers(self.compiler, node, self, **kwargs) @property def defs(self): return set(self.topleveldefs.union(self.closuredefs).values()) def __repr__(self): return ( "Identifiers(declared=%r, locally_declared=%r, " "undeclared=%r, topleveldefs=%r, closuredefs=%r, " "argumentdeclared=%r)" % ( list(self.declared), list(self.locally_declared), list(self.undeclared), [c.name for c in self.topleveldefs.values()], [c.name for c in self.closuredefs.values()], self.argument_declared, ) ) def check_declared(self, node): """update the state of this Identifiers with the undeclared and declared identifiers of the given node.""" for ident in node.undeclared_identifiers(): if ident != "context" and ident not in self.declared.union( self.locally_declared ): self.undeclared.add(ident) for ident in node.declared_identifiers(): self.locally_declared.add(ident) def add_declared(self, ident): self.declared.add(ident) if ident in self.undeclared: self.undeclared.remove(ident) def visitExpression(self, node): self.check_declared(node) def visitControlLine(self, node): self.check_declared(node) def visitCode(self, node): if not node.ismodule: self.check_declared(node) self.locally_assigned = self.locally_assigned.union( node.declared_identifiers() ) def visitNamespaceTag(self, node): # only traverse into the sub-elements of a # <%namespace> tag if we are the branch created in # write_namespaces() if self.node is node: for n in node.nodes: n.accept_visitor(self) def _check_name_exists(self, collection, node): existing = collection.get(node.funcname) collection[node.funcname] = node if ( existing is not None and existing is not node and (node.is_block or existing.is_block) ): raise exceptions.CompileException( "%%def or %%block named '%s' already " "exists in this template." % node.funcname, **node.exception_kwargs, ) def visitDefTag(self, node): if node.is_root() and not node.is_anonymous: self._check_name_exists(self.topleveldefs, node) elif node is not self.node: self._check_name_exists(self.closuredefs, node) for ident in node.undeclared_identifiers(): if ident != "context" and ident not in self.declared.union( self.locally_declared ): self.undeclared.add(ident) # visit defs only one level deep if node is self.node: for ident in node.declared_identifiers(): self.argument_declared.add(ident) for n in node.nodes: n.accept_visitor(self) def visitBlockTag(self, node): if node is not self.node and not node.is_anonymous: if isinstance(self.node, parsetree.DefTag): raise exceptions.CompileException( "Named block '%s' not allowed inside of def '%s'" % (node.name, self.node.name), **node.exception_kwargs, ) elif isinstance( self.node, (parsetree.CallTag, parsetree.CallNamespaceTag) ): raise exceptions.CompileException( "Named block '%s' not allowed inside of <%%call> tag" % (node.name,), **node.exception_kwargs, ) for ident in node.undeclared_identifiers(): if ident != "context" and ident not in self.declared.union( self.locally_declared ): self.undeclared.add(ident) if not node.is_anonymous: self._check_name_exists(self.topleveldefs, node) self.undeclared.add(node.funcname) elif node is not self.node: self._check_name_exists(self.closuredefs, node) for ident in node.declared_identifiers(): self.argument_declared.add(ident) for n in node.nodes: n.accept_visitor(self) def visitTextTag(self, node): for ident in node.undeclared_identifiers(): if ident != "context" and ident not in self.declared.union( self.locally_declared ): self.undeclared.add(ident) def visitIncludeTag(self, node): self.check_declared(node) def visitPageTag(self, node): for ident in node.declared_identifiers(): self.argument_declared.add(ident) self.check_declared(node) def visitCallNamespaceTag(self, node): self.visitCallTag(node) def visitCallTag(self, node): if node is self.node: for ident in node.undeclared_identifiers(): if ident != "context" and ident not in self.declared.union( self.locally_declared ): self.undeclared.add(ident) for ident in node.declared_identifiers(): self.argument_declared.add(ident) for n in node.nodes: n.accept_visitor(self) else: for ident in node.undeclared_identifiers(): if ident != "context" and ident not in self.declared.union( self.locally_declared ): self.undeclared.add(ident) _FOR_LOOP = re.compile( r"^for\s+((?:\(?)\s*" r"(?:\(?)\s*[A-Za-z_][A-Za-z_0-9]*" r"(?:\s*,\s*(?:[A-Za-z_][A-Za-z_0-9]*),??)*\s*(?:\)?)" r"(?:\s*,\s*(?:" r"(?:\(?)\s*[A-Za-z_][A-Za-z_0-9]*" r"(?:\s*,\s*(?:[A-Za-z_][A-Za-z_0-9]*),??)*\s*(?:\)?)" r"),??)*\s*(?:\)?))\s+in\s+(.*):" ) def mangle_mako_loop(node, printer): """converts a for loop into a context manager wrapped around a for loop when access to the `loop` variable has been detected in the for loop body """ loop_variable = LoopVariable() node.accept_visitor(loop_variable) if loop_variable.detected: node.nodes[-1].has_loop_context = True match = _FOR_LOOP.match(node.text) if match: printer.writelines( "loop = __M_loop._enter(%s)" % match.group(2), "try:" # 'with __M_loop(%s) as loop:' % match.group(2) ) text = "for %s in loop:" % match.group(1) else: raise SyntaxError("Couldn't apply loop context: %s" % node.text) else: text = node.text return text class LoopVariable: """A node visitor which looks for the name 'loop' within undeclared identifiers.""" def __init__(self): self.detected = False def _loop_reference_detected(self, node): if "loop" in node.undeclared_identifiers(): self.detected = True else: for n in node.get_children(): n.accept_visitor(self) def visitControlLine(self, node): self._loop_reference_detected(node) def visitCode(self, node): self._loop_reference_detected(node) def visitExpression(self, node): self._loop_reference_detected(node)
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