Merge pull request #1559 from crytic/dev-fix-yul-parsing

Improve yul parsing

slither/core/children/child_function.py

@@ -5,11 +5,11 @@ if TYPE_CHECKING:
 
 
 class ChildFunction:
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__()
         self._function = None
 
-    def set_function(self, function: "Function"):
+    def set_function(self, function: "Function") -> None:
         self._function = function
 
     @property

slither/core/expressions/identifier.py

@@ -7,7 +7,7 @@ if TYPE_CHECKING:
 
 
 class Identifier(ExpressionTyped):
-    def __init__(self, value):
+    def __init__(self, value) -> None:
         super().__init__()
         self._value: "Variable" = value
 
@@ -15,5 +15,5 @@ class Identifier(ExpressionTyped):
     def value(self) -> "Variable":
         return self._value
 
-    def __str__(self):
+    def __str__(self) -> str:
         return str(self._value)

slither/core/variables/local_variable.py

@@ -11,11 +11,11 @@ from slither.core.declarations.structure import Structure
 
 
 class LocalVariable(ChildFunction, Variable):
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__()
         self._location: Optional[str] = None
 
-    def set_location(self, loc: str):
+    def set_location(self, loc: str) -> None:
         self._location = loc
 
     @property

slither/solc_parsing/declarations/function.py

@@ -343,7 +343,6 @@ class FunctionSolc(CallerContextExpression):
             node,
             [self._function.name, f"asm_{len(self._node_to_yulobject)}"],
             scope,
-            parent_func=self._function,
         )
         self._node_to_yulobject[node] = yul_object
         return yul_object

slither/solc_parsing/yul/evm_functions.py

@@ -264,9 +264,9 @@ binary_ops = {
 
 
 class YulBuiltin:  # pylint: disable=too-few-public-methods
-    def __init__(self, name):
+    def __init__(self, name: str) -> None:
         self._name = name
 
     @property
-    def name(self):
+    def name(self) -> str:
         return self._name

slither/solc_parsing/yul/parse_yul.py

@@ -24,6 +24,7 @@ from slither.core.expressions import (
     UnaryOperation,
 )
 from slither.core.expressions.expression import Expression
+from slither.core.scope.scope import FileScope
 from slither.core.solidity_types import ElementaryType
 from slither.core.source_mapping.source_mapping import SourceMapping
 from slither.core.variables.local_variable import LocalVariable
@@ -51,30 +52,35 @@ class YulNode:
     def underlying_node(self) -> Node:
         return self._node
 
-    def add_unparsed_expression(self, expression: Dict):
+    def add_unparsed_expression(self, expression: Dict) -> None:
         assert self._unparsed_expression is None
         self._unparsed_expression = expression
 
-    def analyze_expressions(self):
+    def analyze_expressions(self) -> None:
         if self._node.type == NodeType.VARIABLE and not self._node.expression:
-            self._node.add_expression(self._node.variable_declaration.expression)
+            expression = self._node.variable_declaration.expression
+            if expression:
+                self._node.add_expression(expression)
         if self._unparsed_expression:
             expression = parse_yul(self._scope, self, self._unparsed_expression)
-            self._node.add_expression(expression)
+            if expression:
+                self._node.add_expression(expression)
 
         if self._node.expression:
             if self._node.type == NodeType.VARIABLE:
                 # Update the expression to be an assignement to the variable
-                _expression = AssignmentOperation(
-                    Identifier(self._node.variable_declaration),
-                    self._node.expression,
-                    AssignmentOperationType.ASSIGN,
-                    self._node.variable_declaration.type,
-                )
-                _expression.set_offset(
-                    self._node.expression.source_mapping, self._node.compilation_unit
-                )
-                self._node.add_expression(_expression, bypass_verif_empty=True)
+                variable_declaration = self._node.variable_declaration
+                if variable_declaration:
+                    _expression = AssignmentOperation(
+                        Identifier(self._node.variable_declaration),
+                        self._node.expression,
+                        AssignmentOperationType.ASSIGN,
+                        variable_declaration.type,
+                    )
+                    _expression.set_offset(
+                        self._node.expression.source_mapping, self._node.compilation_unit
+                    )
+                    self._node.add_expression(_expression, bypass_verif_empty=True)
 
             expression = self._node.expression
             read_var = ReadVar(expression)
@@ -122,13 +128,13 @@ class YulScope(metaclass=abc.ABCMeta):
     ]
 
     def __init__(
-        self, contract: Optional[Contract], yul_id: List[str], parent_func: Function = None
-    ):
+        self, contract: Optional[Contract], yul_id: List[str], parent_func: Function
+    ) -> None:
         self._contract = contract
         self._id: List[str] = yul_id
         self._yul_local_variables: List[YulLocalVariable] = []
         self._yul_local_functions: List[YulFunction] = []
-        self._parent_func = parent_func
+        self._parent_func: Function = parent_func
 
     @property
     def id(self) -> List[str]:
@@ -155,10 +161,14 @@ class YulScope(metaclass=abc.ABCMeta):
     def new_node(self, node_type: NodeType, src: Union[str, Dict]) -> YulNode:
         pass
 
-    def add_yul_local_variable(self, var):
+    @property
+    def file_scope(self) -> FileScope:
+        return self._parent_func.file_scope
+
+    def add_yul_local_variable(self, var: "YulLocalVariable") -> None:
         self._yul_local_variables.append(var)
 
-    def get_yul_local_variable_from_name(self, variable_name):
+    def get_yul_local_variable_from_name(self, variable_name: str) -> Optional["YulLocalVariable"]:
         return next(
             (
                 v
@@ -168,10 +178,10 @@ class YulScope(metaclass=abc.ABCMeta):
             None,
         )
 
-    def add_yul_local_function(self, func):
+    def add_yul_local_function(self, func: "YulFunction") -> None:
         self._yul_local_functions.append(func)
 
-    def get_yul_local_function_from_name(self, func_name):
+    def get_yul_local_function_from_name(self, func_name: str) -> Optional["YulLocalVariable"]:
         return next(
             (v for v in self._yul_local_functions if v.underlying.name == func_name),
             None,
@@ -242,7 +252,7 @@ class YulFunction(YulScope):
     def function(self) -> Function:
         return self._function
 
-    def convert_body(self):
+    def convert_body(self) -> None:
         node = self.new_node(NodeType.ENTRYPOINT, self._ast["src"])
         link_underlying_nodes(self._entrypoint, node)
 
@@ -258,7 +268,7 @@ class YulFunction(YulScope):
 
         convert_yul(self, node, self._ast["body"], self.node_scope)
 
-    def parse_body(self):
+    def parse_body(self) -> None:
         for node in self._nodes:
             node.analyze_expressions()
 
@@ -289,9 +299,8 @@ class YulBlock(YulScope):
         entrypoint: Node,
         yul_id: List[str],
         node_scope: Union[Scope, Function],
-        **kwargs,
     ):
-        super().__init__(contract, yul_id, **kwargs)
+        super().__init__(contract, yul_id, entrypoint.function)
 
         self._entrypoint: YulNode = YulNode(entrypoint, self)
         self._nodes: List[YulNode] = []
@@ -318,7 +327,7 @@ class YulBlock(YulScope):
     def convert(self, ast: Dict) -> YulNode:
         return convert_yul(self, self._entrypoint, ast, self.node_scope)
 
-    def analyze_expressions(self):
+    def analyze_expressions(self) -> None:
         for node in self._nodes:
             node.analyze_expressions()
 
@@ -361,18 +370,22 @@ def convert_yul_function_definition(
     while not isinstance(top_node_scope, Function):
         top_node_scope = top_node_scope.father
 
+    func: Union[FunctionTopLevel, FunctionContract]
     if isinstance(top_node_scope, FunctionTopLevel):
-        scope = root.contract.file_scope
+        scope = root.file_scope
         func = FunctionTopLevel(root.compilation_unit, scope)
         # Note: we do not add the function in the scope
         # While its a top level function, it is not accessible outside of the function definition
         # In practice we should probably have a specific function type for function defined within a function
     else:
         func = FunctionContract(root.compilation_unit)
+
     func.function_language = FunctionLanguage.Yul
     yul_function = YulFunction(func, root, ast, node_scope)
 
-    root.contract.add_function(func)
+    if root.contract:
+        root.contract.add_function(func)
+
     root.compilation_unit.add_function(func)
     root.add_yul_local_function(yul_function)
 
@@ -774,14 +787,15 @@ def parse_yul_identifier(root: YulScope, _node: YulNode, ast: Dict) -> Optional[
     # check function-scoped variables
     parent_func = root.parent_func
     if parent_func:
-        variable = parent_func.get_local_variable_from_name(name)
-        if variable:
-            return Identifier(variable)
+        local_variable = parent_func.get_local_variable_from_name(name)
+        if local_variable:
+            return Identifier(local_variable)
 
         if isinstance(parent_func, FunctionContract):
-            variable = parent_func.contract.get_state_variable_from_name(name)
-            if variable:
-                return Identifier(variable)
+            assert parent_func.contract
+            state_variable = parent_func.contract.get_state_variable_from_name(name)
+            if state_variable:
+                return Identifier(state_variable)
 
     # check yul-scoped variable
     variable = root.get_yul_local_variable_from_name(name)
@@ -798,7 +812,7 @@ def parse_yul_identifier(root: YulScope, _node: YulNode, ast: Dict) -> Optional[
     if magic_suffix:
         return magic_suffix
 
-    ret, _ = find_top_level(name, root.contract.file_scope)
+    ret, _ = find_top_level(name, root.file_scope)
     if ret:
         return Identifier(ret)
 
@@ -840,7 +854,7 @@ def parse_yul_unsupported(_root: YulScope, _node: YulNode, ast: Dict) -> Optiona
 
 
 def parse_yul(root: YulScope, node: YulNode, ast: Dict) -> Optional[Expression]:
-    op = parsers.get(ast["nodeType"], parse_yul_unsupported)(root, node, ast)
+    op: Expression = parsers.get(ast["nodeType"], parse_yul_unsupported)(root, node, ast)
     if op:
         op.set_offset(ast["src"], root.compilation_unit)
     return op

tests/ast-parsing/yul-top-level-0.8.0.sol

@@ -0,0 +1,16 @@
+function top_level_yul(int256 c) pure returns (uint result) {
+    assembly {
+        function internal_yul(a) -> b {
+            b := a
+        }
+
+        result := internal_yul(c)
+    }
+}
+
+
+contract Test {
+	function test() public{
+		top_level_yul(10);
+	}
+}

tests/test_ast_parsing.py

@@ -438,6 +438,7 @@ ALL_TESTS = [
     Test("using-for-global-0.8.0.sol", ["0.8.15"]),
     Test("library_event-0.8.16.sol", ["0.8.16"]),
     Test("top-level-struct-0.8.0.sol", ["0.8.0"]),
+    Test("yul-top-level-0.8.0.sol", ["0.8.0"]),
     Test("complex_imports/import_aliases_issue_1319/test.sol", ["0.5.12"]),
 ]
 # create the output folder if needed