ast: Separate validation from properties

gtkblueprinttool/ast.py

@@ -31,22 +31,40 @@ from .xml_emitter import XmlEmitter
 class UI(AstNode):
     """ The AST node for the entire file """
 
-    @validate()
+    @property
     def gir(self):
         gir = GirContext()
+        self._gir_errors = []
+
+        try:
+            gir.add_namespace(self.children[GtkDirective][0].gir_namespace)
+        except CompileError as e:
+            self._gir_errors.append(e)
 
-        gir.add_namespace(self.children[GtkDirective][0].gir_namespace)
         for i in self.children[Import]:
-            gir.add_namespace(i.gir_namespace)
+            try:
+                gir.add_namespace(i.gir_namespace)
+            except CompileError as e:
+                self._gir_errors.append(e)
 
         return gir
 
+
+    @validate()
+    def gir_errors(self):
+        # make sure gir is loaded
+        self.gir
+        if len(self._gir_errors):
+            raise MultipleErrors(self._gir_errors)
+
+
     @validate()
     def at_most_one_template(self):
         if len(self.children[Template]) > 1:
             raise CompileError(f"Only one template may be defined per file, but this file contains {len(self.templates)}",
                                self.children[Template][1].group.start)
 
+
     def emit_xml(self, xml: XmlEmitter):
         xml.start_tag("interface")
         for x in self.children:
@@ -56,10 +74,8 @@ class UI(AstNode):
 
 class GtkDirective(AstNode):
     @validate("version")
-    def gir_namespace(self):
+    def gtk_version(self):
-        if self.tokens["version"] in ["4.0"]:
+        if self.tokens["version"] not in ["4.0"]:
-            return get_namespace("Gtk", self.tokens["version"])
-        else:
             err = CompileError("Only GTK 4 is supported")
             if self.version.startswith("4"):
                 err.hint("Expected the GIR version, not an exact version number. Use `using Gtk 4.0;`.")
@@ -67,6 +83,12 @@ class GtkDirective(AstNode):
                 err.hint("Expected `using Gtk 4.0;`")
             raise err
 
+
+    @property
+    def gir_namespace(self):
+        return get_namespace("Gtk", self.tokens["version"])
+
+
     def emit_xml(self, xml: XmlEmitter):
         xml.put_self_closing("requires", lib="gtk", version=self.tokens["version"])
 
@@ -79,9 +101,13 @@ class Import(AstNode):
 
 class Template(AstNode):
     @validate("namespace", "class_name")
-    def gir_parent(self):
+    def gir_parent_exists(self):
         if not self.tokens["ignore_gir"]:
-            return self.root.gir.get_class(self.tokens["class_name"], self.tokens["namespace"])
+            self.root.gir.validate_class(self.tokens["class_name"], self.tokens["namespace"])
+
+    @property
+    def gir_parent(self):
+        return self.root.gir.get_class(self.tokens["class_name"], self.tokens["namespace"])
 
 
     @docs("namespace")
@@ -106,6 +132,11 @@ class Template(AstNode):
 
 class Object(AstNode):
     @validate("namespace", "class_name")
+    def gir_class_exists(self):
+        if not self.tokens["ignore_gir"]:
+            self.root.gir.validate_class(self.tokens["class_name"], self.tokens["namespace"])
+
+    @property
     def gir_class(self):
         if not self.tokens["ignore_gir"]:
             return self.root.gir.get_class(self.tokens["class_name"], self.tokens["namespace"])
@@ -141,7 +172,7 @@ class Child(AstNode):
 
 
 class ObjectContent(AstNode):
-    @validate()
+    @property
     def gir_class(self):
         if isinstance(self.parent, Template):
             return self.parent.gir_parent
@@ -164,12 +195,13 @@ class ObjectContent(AstNode):
 
 
 class Property(AstNode):
-    @validate()
+    @property
     def gir_property(self):
         if self.gir_class is not None:
             return self.gir_class.properties.get(self.tokens["name"])
 
-    @validate()
+
+    @property
     def gir_class(self):
         parent = self.parent.parent
         if isinstance(parent, Template):
@@ -179,6 +211,7 @@ class Property(AstNode):
         else:
             raise CompilerBugError()
 
+
     @validate("name")
     def property_exists(self):
         if self.gir_class is None:
@@ -233,12 +266,13 @@ class Property(AstNode):
 
 
 class Signal(AstNode):
-    @validate()
+    @property
     def gir_signal(self):
         if self.gir_class is not None:
-            return self.gir_class.signals.get(self.name)
+            return self.gir_class.signals.get(self.tokens["name"])
 
-    @validate()
+
+    @property
     def gir_class(self):
         parent = self.parent.parent
         if isinstance(parent, Template):
@@ -248,6 +282,7 @@ class Signal(AstNode):
         else:
             raise CompilerBugError()
 
+
     @validate("name")
     def signal_exists(self):
         if self.gir_class is None:
@@ -262,7 +297,7 @@ class Signal(AstNode):
 
         if self.gir_signal is None:
             raise CompileError(
-                f"Class {self.gir_class.full_name} does not contain a signal called {self.name}",
+                f"Class {self.gir_class.full_name} does not contain a signal called {self.tokens['name']}",
                 did_you_mean=(self.tokens["name"], self.gir_class.signals.keys())
             )
 

gtkblueprinttool/ast_utils.py

@@ -52,6 +52,7 @@ class AstNode:
 
     def __init_subclass__(cls):
         cls.completers = []
+        cls.validators = [getattr(cls, f) for f in dir(cls) if hasattr(getattr(cls, f), "_validator")]
 
 
     @property
@@ -66,9 +67,9 @@ class AstNode:
         return list(self._get_errors())
 
     def _get_errors(self):
-        for name, attr in self._attrs_by_type(Validator):
+        for validator in self.validators:
             try:
-                getattr(self, name)
+                validator(self)
             except AlreadyCaughtError:
                 pass
             except CompileError as e:
@@ -111,70 +112,40 @@ class AstNode:
         return None
 
 
-class Validator:
+def validate(token_name=None, end_token_name=None, skip_incomplete=False):
-    def __init__(self, func, token_name=None, end_token_name=None):
-        self.func = func
-        self.token_name = token_name
-        self.end_token_name = end_token_name
-
-    def __get__(self, instance, owner):
-        if instance is None:
-            return self
-
-        key = "_validation_result_" + self.func.__name__
-
-        if key + "_err" in instance.__dict__:
-            # If the validator has failed before, raise a generic Exception.
-            # We want anything that depends on this validation result to
-            # fail, but not report the exception twice.
-            raise AlreadyCaughtError()
-
-        if key not in instance.__dict__:
-            try:
-                instance.__dict__[key] = self.func(instance)
-            except CompileError as e:
-                # Mark the validator as already failed so we don't print the
-                # same message again
-                instance.__dict__[key + "_err"] = True
-
-                # If the node is only partially complete, then an error must
-                # have already been reported at the parsing stage
-                if instance.incomplete:
-                    return None
-
-                # This mess of code sets the error's start and end positions
-                # from the tokens passed to the decorator, if they have not
-                # already been set
-                if self.token_name is not None and e.start is None:
-                    group = instance.group.tokens.get(self.token_name)
-                    if self.end_token_name is not None and group is None:
-                        group = instance.group.tokens[self.end_token_name]
-                    e.start = group.start
-                if (self.token_name is not None or self.end_token_name is not None) and e.end is None:
-                    e.end = instance.group.tokens[self.end_token_name or self.token_name].end
-
-                # Re-raise the exception
-                raise e
-            except Exception as e:
-                # If the node is only partially complete, then an error must
-                # have already been reported at the parsing stage
-                if instance.incomplete:
-                    return None
-                else:
-                    raise e
-
-        # Return the validation result (which other validators, or the code
-        # generation phase, might depend on)
-        return instance.__dict__[key]
-
-
-def validate(*args, **kwargs):
     """ Decorator for functions that validate an AST node. Exceptions raised
     during validation are marked with range information from the tokens. Also
     creates a cached property out of the function. """
 
     def decorator(func):
-        return Validator(func, *args, **kwargs)
+        def inner(self):
+            if skip_incomplete and self.incomplete:
+                return
+
+            try:
+                func(self)
+            except CompileError as e:
+                # If the node is only partially complete, then an error must
+                # have already been reported at the parsing stage
+                if self.incomplete:
+                    return
+
+                # This mess of code sets the error's start and end positions
+                # from the tokens passed to the decorator, if they have not
+                # already been set
+                if token_name is not None and e.start is None:
+                    group = self.group.tokens.get(token_name)
+                    if end_token_name is not None and group is None:
+                        group = self.group.tokens[end_token_name]
+                    e.start = group.start
+                if (token_name is not None or end_token_name is not None) and e.end is None:
+                    e.end = self.group.tokens[end_token_name or token_name].end
+
+                # Re-raise the exception
+                raise e
+
+        inner._validator = True
+        return inner
 
     return decorator
 

gtkblueprinttool/gir.py

@@ -203,6 +203,12 @@ class Namespace(GirNode):
     def signature(self):
         return f"namespace {self.name} {self.version}"
 
+
+    def get_type(self, name):
+        """ Gets a type (class, interface, enum, etc.) from this namespace. """
+        return self.classes.get(name) or self.interfaces.get(name)
+
+
     def lookup_class(self, name: str):
         if "." in name:
             ns, cls = name.split(".")
@@ -254,43 +260,43 @@ class GirContext:
         self.namespaces[namespace.name] = namespace
 
 
-    def get_class(self, name: str, ns:str=None) -> Class:
+    def get_type(self, name: str, ns: str) -> GirNode:
-        if ns is None:
+        ns = ns or "Gtk"
-            options = [namespace.classes[name]
-                       for namespace in self.namespaces.values()
-                       if name in namespace.classes]
 
-            if len(options) == 1:
+        if ns not in self.namespaces:
-                return options[0]
+            return None
-            elif len(options) == 0:
-                raise CompileError(
-                    f"No imported namespace contains a class called {name}",
-                    hints=[
-                        "Did you forget to import a namespace?",
-                        "Did you check your spelling?",
-                        "Are your dependencies up to date?",
-                    ],
-                )
-            else:
-                raise CompileError(
-                    f"Class name {name} is ambiguous",
-                    hints=[
-                        f"Specify the namespace, e.g. `{options[0].ns.name}.{name}`",
-                        f"Namespaces with a class named {name}: {', '.join([cls.ns.name for cls in options])}",
-                    ],
-                )
 
-        else:
+        return self.namespaces[ns].get_type(name)
-            if ns not in self.namespaces:
-                raise CompileError(
-                    f"Namespace `{ns}` was not imported.",
-                    did_you_mean=(ns, self.namespaces.keys()),
-                )
 
-            if name not in self.namespaces[ns].classes:
-                raise CompileError(
-                    f"Namespace {ns} does not contain a class called {name}.",
-                    did_you_mean=(name, self.namespaces[ns].classes.keys()),
-                )
 
-            return self.namespaces[ns].classes[name]
+    def get_class(self, name: str, ns: str) -> T.Optional[Class]:
+        type = self.get_type(name, ns)
+        if isinstance(type, Class):
+            return type
+
+
+    def validate_class(self, name: str, ns: str) -> Class:
+        """ Raises an exception if there is a problem looking up the given
+        class (it doesn't exist, it isn't a class, etc.) """
+
+        ns = ns or "Gtk"
+
+        if ns not in self.namespaces:
+            raise CompileError(
+                f"Namespace `{ns}` was not imported.",
+                did_you_mean=(ns, self.namespaces.keys()),
+            )
+
+        type = self.get_type(name, ns)
+
+        if type is None:
+            raise CompileError(
+                f"Namespace {ns} does not contain a class called {name}.",
+                did_you_mean=(name, self.namespaces[ns].classes.keys()),
+            )
+        elif not isinstance(type, Class):
+            raise CompileError(
+                f"{ns}.{name} is not a class.",
+                did_you_mean=(name, self.namespaces[ns].classes.keys()),
+            )
+