Minimal YUL handling

slither/core/declarations/function.py

@@ -89,6 +89,7 @@ class Function(ChildContract, ChildInheritance, SourceMapping):
 
     def __init__(self):
         super(Function, self).__init__()
+        self._scope: List[str] = []
         self._name: Optional[str] = None
         self._view: bool = False
         self._pure: bool = False
@@ -207,7 +208,7 @@ class Function(ChildContract, ChildInheritance, SourceMapping):
             Return the function signature without the return values
         """
         name, parameters, _ = self.signature
-        return name + "(" + ",".join(parameters) + ")"
+        return ".".join(self._scope + [name]) + "(" + ",".join(parameters) + ")"
 
     @property
     def canonical_name(self) -> str:
@@ -216,7 +217,7 @@ class Function(ChildContract, ChildInheritance, SourceMapping):
             Return the function signature without the return values
         """
         name, parameters, _ = self.signature
-        return self.contract_declarer.name + "." + name + "(" + ",".join(parameters) + ")"
+        return ".".join([self.contract_declarer.name] + self._scope + [name]) + "(" + ",".join(parameters) + ")"
 
     @property
     def contains_assembly(self) -> bool:

slither/core/declarations/solidity_variables.py

@@ -90,7 +90,14 @@ class SolidityVariable(Context):
 
     # dev function, will be removed once the code is stable
     def _check_name(self, name: str):
-        assert name in SOLIDITY_VARIABLES
+        assert name in SOLIDITY_VARIABLES or name.endswith("_slot") or name.endswith("_offset")
+
+    @property
+    def state_variable(self):
+        if self._name.endswith("_slot"):
+            return self._name[:-5]
+        if self._name.endswith("_offset"):
+            return self._name[:-7]
 
     @property
     def name(self) -> str:

slither/core/expressions/binary_operation.py

@@ -31,6 +31,12 @@ class BinaryOperationType(Enum):
     ANDAND = 17  # &&
     OROR = 18  # ||
 
+    DIVISION_SIGNED = 19
+    MODULO_SIGNED = 20
+    LESS_SIGNED = 21
+    GREATER_SIGNED = 22
+    RIGHT_SHIFT_ARITHMETIC = 23
+
     @staticmethod
     def get_type(operation_type: "BinaryOperation"):
         if operation_type == "**":
@@ -71,6 +77,16 @@ class BinaryOperationType(Enum):
             return BinaryOperationType.ANDAND
         if operation_type == "||":
             return BinaryOperationType.OROR
+        if operation_type == "/'":
+            return BinaryOperationType.DIVISION_SIGNED
+        if operation_type == "%'":
+            return BinaryOperationType.MODULO_SIGNED
+        if operation_type == "<'":
+            return BinaryOperationType.LESS_SIGNED
+        if operation_type == ">'":
+            return BinaryOperationType.GREATER_SIGNED
+        if operation_type == ">>'":
+            return BinaryOperationType.RIGHT_SHIFT_ARITHMETIC
 
         raise SlitherCoreError("get_type: Unknown operation type {})".format(operation_type))
 
@@ -113,6 +129,16 @@ class BinaryOperationType(Enum):
             return "&&"
         if self == BinaryOperationType.OROR:
             return "||"
+        if self == BinaryOperationType.DIVISION_SIGNED:
+            return "/'"
+        if self == BinaryOperationType.MODULO_SIGNED:
+            return "%'"
+        if self == BinaryOperationType.LESS_SIGNED:
+            return "<'"
+        if self == BinaryOperationType.GREATER_SIGNED:
+            return ">'"
+        if self == BinaryOperationType.RIGHT_SHIFT_ARITHMETIC:
+            return ">>'"
         raise SlitherCoreError("str: Unknown operation type {})".format(self))
 
 

slither/detectors/statements/assembly.py

@@ -30,7 +30,7 @@ class Assembly(AbstractDetector):
         Returns:
             (bool)
         """
-        return node.type == NodeType.ASSEMBLY
+        return node.type == NodeType.ASSEMBLY and len(node.yul_path) == 2
 
     def detect_assembly(self, contract):
         ret = []

slither/printers/summary/slithir.py

@@ -20,7 +20,7 @@ class PrinterSlithIR(AbstractPrinter):
 
         txt = ""
         for contract in self.contracts:
-            txt += 'Contract {}'.format(contract.name)
+            txt += 'Contract {}\n'.format(contract.name)
             for function in contract.functions:
                 txt += f'\tFunction {function.canonical_name} {"" if function.is_shadowed else "(*)"}\n'
                 for node in function.nodes:

slither/slithir/convert.py

@@ -10,6 +10,7 @@ from slither.core.solidity_types import (ArrayType, ElementaryType,
 from slither.core.solidity_types.elementary_type import Int as ElementaryTypeInt
 from slither.core.variables.variable import Variable
 from slither.core.variables.state_variable import StateVariable
+from slither.slithir.operations.codesize import CodeSize
 from slither.slithir.variables import TupleVariable
 from slither.slithir.operations import (Assignment, Balance, Binary,
                                         BinaryType, Call, Condition, Delete,
@@ -512,6 +513,12 @@ def propagate_types(ir, node):
                     b.set_expression(ir.expression)
                     b.set_node(ir.node)
                     return b
+                if ir.variable_right == 'codesize' and not isinstance(ir.variable_left, Contract) and isinstance(
+                        ir.variable_left.type, ElementaryType):
+                    b = CodeSize(ir.variable_left, ir.lvalue)
+                    b.set_expression(ir.expression)
+                    b.set_node(ir.node)
+                    return b
                 if ir.variable_right == 'selector' and isinstance(ir.variable_left.type, Function):
                     assignment = Assignment(ir.lvalue,
                                             Constant(str(get_function_id(ir.variable_left.type.full_name))),

slither/slithir/operations/binary.py

@@ -31,6 +31,12 @@ class BinaryType(Enum):
     ANDAND = 17  # &&
     OROR = 18  # ||
 
+    DIVISION_SIGNED = 19
+    MODULO_SIGNED = 20
+    LESS_SIGNED = 21
+    GREATER_SIGNED = 22
+    RIGHT_SHIFT_ARITHMETIC = 23
+
     @staticmethod
     def return_bool(operation_type):
         return operation_type in [BinaryType.OROR,
@@ -82,6 +88,16 @@ class BinaryType(Enum):
             return BinaryType.ANDAND
         if operation_type == '||':
             return BinaryType.OROR
+        if operation_type == "/'":
+            return BinaryType.DIVISION_SIGNED
+        if operation_type == "%'":
+            return BinaryType.MODULO_SIGNED
+        if operation_type == "<'":
+            return BinaryType.LESS_SIGNED
+        if operation_type == ">'":
+            return BinaryType.GREATER_SIGNED
+        if operation_type == ">>'":
+            return BinaryType.RIGHT_SHIFT_ARITHMETIC
 
         raise SlithIRError('get_type: Unknown operation type {})'.format(operation_type))
 
@@ -124,6 +140,16 @@ class BinaryType(Enum):
             return "&&"
         if self == BinaryType.OROR:
             return "||"
+        if self == BinaryType.DIVISION_SIGNED:
+            return "/'"
+        if self == BinaryType.MODULO_SIGNED:
+            return "%'"
+        if self == BinaryType.LESS_SIGNED:
+            return "<'"
+        if self == BinaryType.GREATER_SIGNED:
+            return ">'"
+        if self == BinaryType.RIGHT_SHIFT_ARITHMETIC:
+            return ">>'"
         raise SlithIRError("str: Unknown operation type {} {})".format(self, type(self)))
 
 

slither/slithir/operations/codesize.py

@@ -0,0 +1,24 @@
+from slither.core.solidity_types import ElementaryType
+from slither.slithir.operations.lvalue import OperationWithLValue
+from slither.slithir.utils.utils import is_valid_lvalue, is_valid_rvalue
+
+
+class CodeSize(OperationWithLValue):
+
+    def __init__(self, value, lvalue):
+        assert is_valid_rvalue(value)
+        assert is_valid_lvalue(lvalue)
+        self._value = value
+        self._lvalue = lvalue
+        lvalue.set_type(ElementaryType('uint256'))
+
+    @property
+    def read(self):
+        return [self._value]
+
+    @property
+    def value(self):
+        return self._value
+
+    def __str__(self):
+        return "{} -> CODESIZE {}".format(self.lvalue, self.value)

slither/slithir/utils/ssa.py

@@ -17,6 +17,7 @@ from slither.slithir.operations import (Assignment, Balance, Binary, Condition,
                                         Push, Return, Send, SolidityCall,
                                         Transfer, TypeConversion, Unary,
                                         Unpack, Nop)
+from slither.slithir.operations.codesize import CodeSize
 from slither.slithir.variables import (Constant, LocalIRVariable,
                                        ReferenceVariable, ReferenceVariableSSA,
                                        StateIRVariable, TemporaryVariable,
@@ -527,6 +528,10 @@ def copy_ir(ir, *instances):
         variable_right = get_variable(ir, lambda x: x.variable_right, *instances)
         operation_type = ir.type
         return Binary(lvalue, variable_left, variable_right, operation_type)
+    elif isinstance(ir, CodeSize):
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
+        value = get_variable(ir, lambda x: x.value, *instances)
+        return CodeSize(value, lvalue)
     elif isinstance(ir, Condition):
         val = get_variable(ir, lambda x: x.value, *instances)
         return Condition(val)

slither/solc_parsing/cfg/node.py

@@ -9,6 +9,7 @@ from slither.core.expressions.assignment_operation import (
 from slither.core.expressions.identifier import Identifier
 from slither.solc_parsing.expressions.expression_parsing import parse_expression
 from slither.visitors.expression.find_calls import FindCalls
+from slither.solc_parsing.yul.parse_yul import parse_yul
 from slither.visitors.expression.read_var import ReadVar
 from slither.visitors.expression.write_var import WriteVar
 
@@ -17,15 +18,57 @@ class NodeSolc:
     def __init__(self, node: Node):
         self._unparsed_expression: Optional[Dict] = None
         self._node = node
+        self._unparsed_yul_expression = None
+
+        """
+        todo this should really go somewhere else, but until
+        that happens I'm setting it to None for performance
+        """
+        self._yul_local_variables = None
+        self._yul_local_functions = None
+        self._yul_path = None
 
     @property
     def underlying_node(self) -> Node:
         return self._node
 
+    def set_yul_root(self, func):
+        self._yul_path = [func.name, f"asm_{func._counter_asm_nodes}"]
+
+    def set_yul_child(self, parent, cur):
+        self._yul_path = parent.yul_path +  [cur]
+
+    @property
+    def yul_path(self):
+        return self._yul_path
+
+    def format_canonical_yul_name(self, name, off=None):
+        return ".".join(self._yul_path[:off] + [name])
+
+    def add_yul_local_variable(self, var):
+        if not self._yul_local_variables:
+            self._yul_local_variables = []
+        self._yul_local_variables.append(var)
+
+    def get_yul_local_variable_from_name(self, variable_name):
+        return next((v for v in self._yul_local_variables if v.name == variable_name), None)
+
+    def add_yul_local_function(self, func):
+        if not self._yul_local_functions:
+            self._yul_local_functions = []
+        self._yul_local_functions.append(func)
+
+    def get_yul_local_function_from_name(self, func_name):
+        return next((v for v in self._yul_local_functions if v.name == func_name), None)
+
     def add_unparsed_expression(self, expression: Dict):
         assert self._unparsed_expression is None
         self._unparsed_expression = expression
 
+    def add_unparsed_yul_expression(self, root, expression):
+        assert self._unparsed_expression is None
+        self._unparsed_yul_expression = (root, expression)
+
     def analyze_expressions(self, caller_context):
         if self._node.type == NodeType.VARIABLE and not self._node.expression:
             self._node.add_expression(self._node.variable_declaration.expression)
@@ -34,6 +77,11 @@ class NodeSolc:
             self._node.add_expression(expression)
             # self._unparsed_expression = None
 
+        if self._unparsed_yul_expression:
+            expression = parse_yul(self._unparsed_yul_expression[0], self, self._unparsed_yul_expression[1])
+            self._expression = expression
+            self._unparsed_yul_expression = None
+
         if self._node.expression:
 
             if self._node.type == NodeType.VARIABLE:

slither/solc_parsing/declarations/function.py

@@ -18,6 +18,7 @@ from slither.solc_parsing.variables.local_variable_init_from_tuple import (
     LocalVariableInitFromTupleSolc,
 )
 from slither.solc_parsing.variables.variable_declaration import MultipleVariablesDeclaration
+from slither.solc_parsing.yul.parse_yul import convert_yul
 from slither.utils.expression_manipulations import SplitTernaryExpression
 from slither.visitors.expression.export_values import ExportValues
 from slither.visitors.expression.has_conditional import HasConditional
@@ -62,6 +63,8 @@ class FunctionSolc:
         self._functionNotParsed = function_data
         self._params_was_analyzed = False
         self._content_was_analyzed = False
+        self._counter_nodes = 0
+        self._counter_asm_nodes = 0
 
         self._counter_scope_local_variables = 0
         # variable renamed will map the solc id
@@ -312,6 +315,9 @@ class FunctionSolc:
         self._node_to_nodesolc[node] = node_parser
         return node_parser
 
+    def node_solc(self):
+        return NodeSolc
+
     # endregion
     ###################################################################################
     ###################################################################################
@@ -797,13 +803,23 @@ class FunctionSolc:
         elif name == "Block":
             node = self._parse_block(statement, node)
         elif name == "InlineAssembly":
-            asm_node = self._new_node(NodeType.ASSEMBLY, statement["src"])
-            self._function.contains_assembly = True
-            # Added with solc 0.4.12
-            if "operations" in statement:
-                asm_node.underlying_node.add_inline_asm(statement["operations"])
-            link_underlying_nodes(node, asm_node)
-            node = asm_node
+            # Added with solc 0.6 - the yul code is an AST
+            if 'AST' in statement:
+                self._contains_assembly = True
+                yul_root = self._new_node(NodeType.ASSEMBLY, statement['src'])
+                yul_root.set_yul_root(self)
+                link_underlying_nodes(node, yul_root)
+                self._counter_asm_nodes += 1
+
+                node = convert_yul(yul_root, yul_root, statement['AST'])
+            else:
+                asm_node = self._new_node(NodeType.ASSEMBLY, statement['src'])
+                self._function._contains_assembly = True
+                # Added with solc 0.4.12
+                if 'operations' in statement:
+                    asm_node.underlying_node.add_inline_asm(statement['operations'])
+                link_underlying_nodes(node, asm_node)
+                node = asm_node
         elif name == "DoWhileStatement":
             node = self._parse_dowhile(statement, node)
         # For Continue / Break / Return / Throw

slither/solc_parsing/yul/evm_functions.py

@@ -0,0 +1,268 @@
+from slither.core.declarations.solidity_variables import SOLIDITY_FUNCTIONS
+from slither.core.expressions import BinaryOperationType, UnaryOperationType
+
+# taken from https://github.com/ethereum/solidity/blob/356cc91084114f840da66804b2a9fc1ac2846cff/libevmasm/Instruction.cpp#L180
+evm_opcodes = [
+    "STOP",
+    "ADD",
+    "SUB",
+    "MUL",
+    "DIV",
+    "SDIV",
+    "MOD",
+    "SMOD",
+    "EXP",
+    "NOT",
+    "LT",
+    "GT",
+    "SLT",
+    "SGT",
+    "EQ",
+    "ISZERO",
+    "AND",
+    "OR",
+    "XOR",
+    "BYTE",
+    "SHL",
+    "SHR",
+    "SAR",
+    "ADDMOD",
+    "MULMOD",
+    "SIGNEXTEND",
+    "KECCAK256",
+    "ADDRESS",
+    "BALANCE",
+    "ORIGIN",
+    "CALLER",
+    "CALLVALUE",
+    "CALLDATALOAD",
+    "CALLDATASIZE",
+    "CALLDATACOPY",
+    "CODESIZE",
+    "CODECOPY",
+    "GASPRICE",
+    "EXTCODESIZE",
+    "EXTCODECOPY",
+    "RETURNDATASIZE",
+    "RETURNDATACOPY",
+    "EXTCODEHASH",
+    "BLOCKHASH",
+    "COINBASE",
+    "TIMESTAMP",
+    "NUMBER",
+    "DIFFICULTY",
+    "GASLIMIT",
+    "CHAINID",
+    "SELFBALANCE",
+    "POP",
+    "MLOAD",
+    "MSTORE",
+    "MSTORE8",
+    "SLOAD",
+    "SSTORE",
+    "JUMP",
+    "JUMPI",
+    "PC",
+    "MSIZE",
+    "GAS",
+    "JUMPDEST",
+    "PUSH1",
+    "PUSH2",
+    "PUSH3",
+    "PUSH4",
+    "PUSH5",
+    "PUSH6",
+    "PUSH7",
+    "PUSH8",
+    "PUSH9",
+    "PUSH10",
+    "PUSH11",
+    "PUSH12",
+    "PUSH13",
+    "PUSH14",
+    "PUSH15",
+    "PUSH16",
+    "PUSH17",
+    "PUSH18",
+    "PUSH19",
+    "PUSH20",
+    "PUSH21",
+    "PUSH22",
+    "PUSH23",
+    "PUSH24",
+    "PUSH25",
+    "PUSH26",
+    "PUSH27",
+    "PUSH28",
+    "PUSH29",
+    "PUSH30",
+    "PUSH31",
+    "PUSH32",
+    "DUP1",
+    "DUP2",
+    "DUP3",
+    "DUP4",
+    "DUP5",
+    "DUP6",
+    "DUP7",
+    "DUP8",
+    "DUP9",
+    "DUP10",
+    "DUP11",
+    "DUP12",
+    "DUP13",
+    "DUP14",
+    "DUP15",
+    "DUP16",
+    "SWAP1",
+    "SWAP2",
+    "SWAP3",
+    "SWAP4",
+    "SWAP5",
+    "SWAP6",
+    "SWAP7",
+    "SWAP8",
+    "SWAP9",
+    "SWAP10",
+    "SWAP11",
+    "SWAP12",
+    "SWAP13",
+    "SWAP14",
+    "SWAP15",
+    "SWAP16",
+    "LOG0",
+    "LOG1",
+    "LOG2",
+    "LOG3",
+    "LOG4",
+    "CREATE",
+    "CALL",
+    "CALLCODE",
+    "STATICCALL",
+    "RETURN",
+    "DELEGATECALL",
+    "CREATE2",
+    "REVERT",
+    "INVALID",
+    "SELFDESTRUCT",
+]
+
+yul_funcs = [
+    "datasize",
+    "dataoffset",
+    "datacopy",
+    "setimmutable",
+    "loadimmutable",
+]
+
+builtins = [x.lower() for x in evm_opcodes if not (
+        x.startswith("PUSH") or
+        x.startswith("SWAP") or
+        x.startswith("DUP") or
+        x == "JUMP" or
+        x == "JUMPI" or
+        x == "JUMPDEST"
+)] + yul_funcs
+
+function_args = {
+    'byte': [2, 1],
+    'addmod': [3, 1],
+    'mulmod': [3, 1],
+    'signextend': [2, 1],
+    'keccak256': [2, 1],
+    'pc': [0, 1],
+    'pop': [1, 0],
+    'mload': [1, 1],
+    'mstore': [2, 0],
+    'mstore8': [2, 0],
+    'sload': [1, 1],
+    'sstore': [2, 0],
+    'msize': [1, 1],
+    'gas': [0, 1],
+    'address': [0, 1],
+    'balance': [1, 1],
+    'selfbalance': [0, 1],
+    'caller': [0, 1],
+    'callvalue': [0, 1],
+    'calldataload': [1, 1],
+    'calldatasize': [0, 1],
+    'calldatacopy': [3, 0],
+    'codesize': [0, 1],
+    'codecopy': [3, 0],
+    'extcodesize': [1, 1],
+    'extcodecopy': [4, 0],
+    'returndatasize': [0, 1],
+    'returndatacopy': [3, 0],
+    'extcodehash': [1, 1],
+    'create': [3, 1],
+    'create2': [4, 1],
+    'call': [7, 1],
+    'callcode': [7, 1],
+    'delegatecall': [6, 1],
+    'staticcall': [6, 1],
+    'return': [2, 0],
+    'revert': [2, 0],
+    'selfdestruct': [1, 0],
+    'invalid': [0, 0],
+    'log0': [2, 0],
+    'log1': [3, 0],
+    'log2': [4, 0],
+    'log3': [5, 0],
+    'log4': [6, 0],
+    'chainid': [0, 1],
+    'origin': [0, 1],
+    'gasprice': [0, 1],
+    'blockhash': [1, 1],
+    'coinbase': [0, 1],
+    'timestamp': [0, 1],
+    'number': [0, 1],
+    'difficulty': [0, 1],
+    'gaslimit': [0, 1],
+}
+
+
+def format_function_descriptor(name):
+    if name not in function_args:
+        return name + "()"
+
+    return name + "(" + ",".join(["uint256"] * function_args[name][0]) + ")"
+
+
+for k, v in function_args.items():
+    SOLIDITY_FUNCTIONS[format_function_descriptor(k)] = ['uint256'] * v[1]
+
+unary_ops = {
+    'not': UnaryOperationType.TILD,
+    'iszero': UnaryOperationType.BANG,
+}
+
+binary_ops = {
+    'add': BinaryOperationType.ADDITION,
+    'sub': BinaryOperationType.SUBTRACTION,
+    'mul': BinaryOperationType.MULTIPLICATION,
+    'div': BinaryOperationType.DIVISION,
+    'sdiv': BinaryOperationType.DIVISION_SIGNED,
+    'mod': BinaryOperationType.MODULO,
+    'smod': BinaryOperationType.MODULO_SIGNED,
+    'exp': BinaryOperationType.POWER,
+    'lt': BinaryOperationType.LESS,
+    'gt': BinaryOperationType.GREATER,
+    'slt': BinaryOperationType.LESS_SIGNED,
+    'sgt': BinaryOperationType.GREATER_SIGNED,
+    'eq': BinaryOperationType.EQUAL,
+    'and': BinaryOperationType.AND,
+    'or': BinaryOperationType.OR,
+    'xor': BinaryOperationType.CARET,
+    'shl': BinaryOperationType.LEFT_SHIFT,
+    'shr': BinaryOperationType.RIGHT_SHIFT,
+    'sar': BinaryOperationType.RIGHT_SHIFT_ARITHMETIC,
+}
+
+
+class YulBuiltin:
+    def __init__(self, name):
+        self._name = name
+
+    @property
+    def name(self):
+        return self._name

slither/solc_parsing/yul/parse_yul.py

@@ -0,0 +1,525 @@
+import json
+
+from slither.core.cfg.node import NodeType, link_nodes
+from slither.core.declarations import Function, SolidityFunction, SolidityVariable
+from slither.core.expressions import (
+    Literal,
+    AssignmentOperation,
+    AssignmentOperationType,
+    Identifier, CallExpression, TupleExpression, BinaryOperation, UnaryOperation,
+)
+from slither.core.solidity_types import ElementaryType
+from slither.core.variables.local_variable import LocalVariable
+from slither.exceptions import SlitherException
+from slither.solc_parsing.yul.evm_functions import *
+
+
+class YulLocalVariable(LocalVariable):
+
+    def __init__(self, ast):
+        super(LocalVariable, self).__init__()
+
+        assert (ast['nodeType'] == 'YulTypedName')
+        self._name = ast['name']
+        self._type = ElementaryType('uint256')
+
+        self._location = 'memory'
+
+
+class YulFunction(Function):
+
+    def __init__(self, ast, root):
+        super(YulFunction, self).__init__()
+
+        assert (ast['nodeType'] == 'YulFunctionDefinition')
+
+        self._contract = root.function.contract
+        self._contract_declarer = root.function.contract_declarer
+
+        self._name = ast['name']
+        self._scope = root.yul_path
+        self._counter_nodes = 0
+
+        self._is_implemented = True
+        self._contains_assembly = True
+
+        self._node_solc = root.function.node_solc()
+
+        self._entry_point = self.new_node(NodeType.ASSEMBLY, ast['src'])
+        self._entry_point.set_yul_child(root, ast['name'])
+
+        self._ast = ast
+        self.set_offset(ast['src'], root.function.slither)
+
+    def convert_body(self):
+        node = self.new_node(NodeType.ENTRYPOINT, self._ast['src'])
+        link_nodes(self.entry_point, node)
+
+        for param in self._ast.get('parameters', []):
+            node = convert_yul(self.entry_point, node, param)
+            self._parameters.append(self.entry_point.get_yul_local_variable_from_name(param['name']))
+
+        for ret in self._ast.get('returnVariables', []):
+            node = convert_yul(self.entry_point, node, ret)
+            self._returns.append(self.entry_point.get_yul_local_variable_from_name(ret['name']))
+
+        convert_yul(self.entry_point, node, self._ast['body'])
+
+    def parse_body(self):
+        for node in self.nodes:
+            node.analyze_expressions(self)
+
+    def node_solc(self):
+        return self._node_solc
+
+    def new_node(self, node_type, src):
+        node = self._node_solc(node_type, self._counter_nodes)
+        node.set_offset(src, self.slither)
+        node.set_function(self)
+        self._counter_nodes += 1
+        self._nodes.append(node)
+        return node
+
+
+###################################################################################
+###################################################################################
+# region Block conversion
+###################################################################################
+###################################################################################
+
+"""
+The functions in this region, at a high level, will extract the control flow
+structures and metadata from the input AST. These include things like function
+definitions and local variables.
+
+Each function takes three parameters:
+    1)  root is a NodeSolc of NodeType.ASSEMBLY, and stores information at the
+        local scope. In Yul, variables are scoped to the function they're
+        declared in (except for variables outside the assembly block)
+    2)  parent is the last node in the CFG. new nodes should be linked against
+        this node
+    3)  ast is a dictionary and is the current node in the Yul ast being converted
+    
+Each function must return a single parameter:
+    1) A NodeSolc representing the new end of the CFG
+
+The entrypoint is the function at the end of this region, `convert_yul`, which
+dispatches to a specialized function based on a lookup dictionary.
+"""
+
+
+def convert_yul_block(root, parent, ast):
+    for statement in ast["statements"]:
+        parent = convert_yul(root, parent, statement)
+    return parent
+
+
+def convert_yul_function_definition(root, parent, ast):
+    f = YulFunction(ast, root)
+
+    root.function.contract._functions[root.format_canonical_yul_name(f.name)] = f
+
+    f.convert_body()
+    f.parse_body()
+
+    return parent
+
+
+def convert_yul_variable_declaration(root, parent, ast):
+    for variable_ast in ast['variables']:
+        parent = convert_yul(root, parent, variable_ast)
+
+    node = parent.function.new_node(NodeType.EXPRESSION, ast["src"])
+    node.add_unparsed_yul_expression(root, ast)
+    link_nodes(parent, node)
+
+    return node
+
+
+def convert_yul_assignment(root, parent, ast):
+    node = parent.function.new_node(NodeType.EXPRESSION, ast["src"])
+    node.add_unparsed_yul_expression(root, ast)
+    link_nodes(parent, node)
+    return node
+
+
+def convert_yul_expression_statement(root, parent, ast):
+    src = ast['src']
+    expression_ast = ast['expression']
+
+    expression = parent.function.new_node(NodeType.EXPRESSION, src)
+    expression.add_unparsed_yul_expression(root, expression_ast)
+    link_nodes(parent, expression)
+
+    return expression
+
+
+def convert_yul_if(root, parent, ast):
+    # we're cheating and pretending that yul supports if/else so we can convert switch cleaner
+
+    src = ast['src']
+    condition_ast = ast['condition']
+    true_body_ast = ast['body']
+    false_body_ast = ast['false_body'] if 'false_body' in ast else None
+
+    condition = parent.function.new_node(NodeType.IF, src)
+    end = parent.function.new_node(NodeType.ENDIF, src)
+
+    condition.add_unparsed_yul_expression(root, condition_ast)
+
+    true_body = convert_yul(root, condition, true_body_ast)
+
+    if false_body_ast:
+        false_body = convert_yul(root, condition, false_body_ast)
+        link_nodes(false_body, end)
+    else:
+        link_nodes(condition, end)
+
+    link_nodes(parent, condition)
+    link_nodes(true_body, end)
+
+    return end
+
+
+def convert_yul_switch(root, parent, ast):
+    """
+    This is unfortunate. We don't really want a switch in our IR so we're going to
+    translate it into a series of if/else statements.
+    """
+    cases_ast = ast['cases']
+    expression_ast = ast['expression']
+
+    # this variable stores the result of the expression so we don't accidentally compute it more than once
+    switch_expr_var = 'switch_expr_{}'.format(ast['src'].replace(':', '_'))
+
+    rewritten_switch = {
+        'nodeType': 'YulBlock',
+        'src': ast['src'],
+        'statements': [
+            {
+                'nodeType': 'YulVariableDeclaration',
+                'src': expression_ast['src'],
+                'variables': [
+                    {
+                        'nodeType': 'YulTypedName',
+                        'src': expression_ast['src'],
+                        'name': switch_expr_var,
+                        'type': '',
+                    },
+                ],
+                'value': expression_ast,
+            },
+        ],
+    }
+
+    last_if = None
+
+    default_ast = None
+
+    for case_ast in cases_ast:
+        body_ast = case_ast['body']
+        value_ast = case_ast['value']
+
+        if value_ast == 'default':
+            default_ast = case_ast
+            continue
+
+        current_if = {
+            'nodeType': 'YulIf',
+            'src': case_ast['src'],
+            'condition': {
+                'nodeType': 'YulFunctionCall',
+                'src': case_ast['src'],
+                'functionName': {
+                    'nodeType': 'YulIdentifier',
+                    'src': case_ast['src'],
+                    'name': 'eq',
+                },
+                'arguments': [
+                    {
+                        'nodeType': 'YulIdentifier',
+                        'src': case_ast['src'],
+                        'name': switch_expr_var,
+                    },
+                    value_ast,
+                ]
+            },
+            'body': body_ast,
+        }
+
+        if last_if:
+            last_if['false_body'] = current_if
+        else:
+            rewritten_switch['statements'].append(current_if)
+
+        last_if = current_if
+
+    if default_ast:
+        body_ast = default_ast['body']
+
+        if last_if:
+            last_if['false_body'] = body_ast
+        else:
+            rewritten_switch['statements'].append(body_ast)
+
+    return convert_yul(root, parent, rewritten_switch)
+
+
+def convert_yul_for_loop(root, parent, ast):
+    pre_ast = ast['pre']
+    condition_ast = ast['condition']
+    post_ast = ast['post']
+    body_ast = ast['body']
+
+    start_loop = parent.function.new_node(NodeType.STARTLOOP, ast['src'])
+    end_loop = parent.function.new_node(NodeType.ENDLOOP, ast['src'])
+
+    link_nodes(parent, start_loop)
+
+    pre = convert_yul(root, start_loop, pre_ast)
+
+    condition = parent.function.new_node(NodeType.IFLOOP, condition_ast['src'])
+    condition.add_unparsed_yul_expression(root, condition_ast)
+    link_nodes(pre, condition)
+
+    link_nodes(condition, end_loop)
+
+    body = convert_yul(root, condition, body_ast)
+
+    post = convert_yul(root, body, post_ast)
+
+    link_nodes(post, condition)
+
+    return end_loop
+
+
+def convert_yul_break(root, parent, ast):
+    break_ = parent.function.new_node(NodeType.BREAK, ast['src'])
+    link_nodes(parent, break_)
+    return break_
+
+
+def convert_yul_continue(root, parent, ast):
+    continue_ = parent.function.new_node(NodeType.CONTINUE, ast['src'])
+    link_nodes(parent, continue_)
+    return continue_
+
+
+def convert_yul_leave(root, parent, ast):
+    leave = parent.function.new_node(NodeType.RETURN, ast['src'])
+    link_nodes(parent, leave)
+    return leave
+
+
+def convert_yul_typed_name(root, parent, ast):
+    var = YulLocalVariable(ast)
+    var.set_function(root.function)
+    var.set_offset(ast['src'], root.slither)
+
+    root.add_yul_local_variable(var)
+
+    node = parent.function.new_node(NodeType.VARIABLE, ast['src'])
+    node.add_variable_declaration(var)
+    link_nodes(parent, node)
+
+    return node
+
+
+def convert_yul_unsupported(root, parent, ast):
+    raise SlitherException(f"no converter available for {ast['nodeType']} {json.dumps(ast, indent=2)}")
+
+
+def convert_yul(root, parent, ast):
+    return converters.get(ast['nodeType'], convert_yul_unsupported)(root, parent, ast)
+
+
+converters = {
+    'YulBlock': convert_yul_block,
+    'YulFunctionDefinition': convert_yul_function_definition,
+    'YulVariableDeclaration': convert_yul_variable_declaration,
+    'YulAssignment': convert_yul_assignment,
+    'YulExpressionStatement': convert_yul_expression_statement,
+    'YulIf': convert_yul_if,
+    'YulSwitch': convert_yul_switch,
+    'YulForLoop': convert_yul_for_loop,
+    'YulBreak': convert_yul_break,
+    'YulContinue': convert_yul_continue,
+    'YulLeave': convert_yul_leave,
+    'YulTypedName': convert_yul_typed_name,
+}
+
+# endregion
+###################################################################################
+###################################################################################
+
+###################################################################################
+###################################################################################
+# region Expression parsing
+###################################################################################
+###################################################################################
+
+"""
+The functions in this region parse the AST into expressions.
+
+Each function takes three parameters:
+    1)  root is the same root as above
+    2)  node is the CFG node which stores this expression
+    3)  ast is the same ast as above
+    
+Each function must return a single parameter:
+    1) The operation that was parsed, or None
+
+The entrypoint is the function at the end of this region, `parse_yul`, which
+dispatches to a specialized function based on a lookup dictionary.
+"""
+
+
+def _parse_yul_assignment_common(root, node, ast, key):
+    lhs = [parse_yul(root, node, arg) for arg in ast[key]]
+    rhs = parse_yul(root, node, ast['value'])
+
+    return AssignmentOperation(vars_to_val(lhs), rhs, AssignmentOperationType.ASSIGN, vars_to_typestr(lhs))
+
+
+def parse_yul_variable_declaration(root, node, ast):
+    """
+    We already created variables in the conversion phase, so just do
+    the assignment
+    """
+
+    if not ast['value']:
+        return None
+
+    return _parse_yul_assignment_common(root, node, ast, 'variables')
+
+
+def parse_yul_assignment(root, node, ast):
+    return _parse_yul_assignment_common(root, node, ast, 'variableNames')
+
+
+def parse_yul_function_call(root, node, ast):
+    args = [parse_yul(root, node, arg) for arg in ast['arguments']]
+    ident = parse_yul(root, node, ast['functionName'])
+
+    if isinstance(ident.value, YulBuiltin):
+        name = ident.value.name
+        if name in binary_ops:
+            if name in ['shl', 'shr', 'sar']:
+                # lmao ok
+                return BinaryOperation(args[1], args[0], binary_ops[name])
+
+            return BinaryOperation(args[0], args[1], binary_ops[name])
+
+        if name in unary_ops:
+            return UnaryOperation(args[0], unary_ops[name])
+
+        ident = Identifier(SolidityFunction(format_function_descriptor(ident.value.name)))
+
+    if isinstance(ident.value, Function):
+        return CallExpression(ident, args, vars_to_typestr(ident.value.returns))
+    elif isinstance(ident.value, SolidityFunction):
+        return CallExpression(ident, args, vars_to_typestr(ident.value.return_type))
+    else:
+        raise SlitherException(f"unexpected function call target type {str(type(ident.value))}")
+
+
+def parse_yul_identifier(root, node, ast):
+    name = ast['name']
+
+    if name in builtins:
+        return Identifier(YulBuiltin(name))
+
+    # check function-scoped variables
+    variable = root.function.get_local_variable_from_name(name)
+    if variable:
+        return Identifier(variable)
+
+    # check yul-scoped variable
+    variable = root.get_yul_local_variable_from_name(name)
+    if variable:
+        return Identifier(variable)
+
+    # check yul-scoped function
+    # note that a function can recurse into itself, so we have two canonical names
+    # to check (but only one of them can be valid)
+
+    functions = root.function.contract_declarer._functions
+
+    canonical_name = root.format_canonical_yul_name(name)
+    if canonical_name in functions:
+        return Identifier(functions[canonical_name])
+
+    canonical_name = root.format_canonical_yul_name(name, -1)
+    if canonical_name in functions:
+        return Identifier(functions[canonical_name])
+
+    # check for magic suffixes
+    if name.endswith("_slot"):
+        potential_name = name[:-5]
+        var = root.function.contract.get_state_variable_from_name(potential_name)
+        if var:
+            return Identifier(SolidityVariable(name))
+    if name.endswith("_offset"):
+        potential_name = name[:-7]
+        var = root.function.contract.get_state_variable_from_name(potential_name)
+        if var:
+            return Identifier(SolidityVariable(name))
+
+    raise SlitherException(f"unresolved reference to identifier {name}")
+
+
+def parse_yul_literal(root, node, ast):
+    type_ = ast['type']
+    value = ast['value']
+
+    if not type_:
+        type_ = 'bool' if value in ['true', 'false'] else 'uint256'
+
+    return Literal(value, ElementaryType(type_))
+
+
+def parse_yul_typed_name(root, node, ast):
+    var = root.get_yul_local_variable_from_name(ast['name'])
+
+    i = Identifier(var)
+    i._type = var.type
+    return i
+
+
+def parse_yul_unsupported(root, node, ast):
+    raise SlitherException(f"no parser available for {ast['nodeType']} {json.dumps(ast, indent=2)}")
+
+
+def parse_yul(root, node, ast):
+    op = parsers.get(ast['nodeType'], parse_yul_unsupported)(root, node, ast)
+    if op:
+        op.set_offset(ast["src"], root.slither)
+    return op
+
+
+parsers = {
+    'YulVariableDeclaration': parse_yul_variable_declaration,
+    'YulAssignment': parse_yul_assignment,
+    'YulFunctionCall': parse_yul_function_call,
+    'YulIdentifier': parse_yul_identifier,
+    'YulTypedName': parse_yul_typed_name,
+    'YulLiteral': parse_yul_literal,
+}
+
+
+# endregion
+###################################################################################
+###################################################################################
+
+def vars_to_typestr(rets):
+    if len(rets) == 0:
+        return ""
+    if len(rets) == 1:
+        return str(rets[0].type)
+    return "tuple({})".format(",".join(str(ret.type) for ret in rets))
+
+
+def vars_to_val(vars):
+    if len(vars) == 1:
+        return vars[0]
+    return TupleExpression(vars)

slither/visitors/slithir/expression_to_slithir.py

@@ -1,9 +1,9 @@
 import logging
 
-from slither.core.declarations import Function
+from slither.core.declarations import Function, SolidityVariable, SolidityVariableComposed
 from slither.core.expressions import (AssignmentOperationType,
                                       UnaryOperationType, BinaryOperationType)
-from slither.core.solidity_types import ArrayType
+from slither.core.solidity_types import ArrayType, ElementaryType
 from slither.core.solidity_types.type import Type
 from slither.slithir.operations import (Assignment, Binary, BinaryType, Delete,
                                         Index, InitArray, InternalCall, Member,
@@ -167,27 +167,63 @@ class ExpressionToSlithIR(ExpressionVisitor):
             self._result.append(internal_call)
             set_val(expression, val)
         else:
-            # If tuple
-            if expression.type_call.startswith('tuple(') and expression.type_call != 'tuple()':
-                val = TupleVariable(self._node)
-            else:
+            # yul things
+            if called.name == 'caller()':
                 val = TemporaryVariable(self._node)
-
-            message_call = TmpCall(called, len(args), val, expression.type_call)
-            message_call.set_expression(expression)
-            # Gas/value are only accessible here if the syntax {gas: , value: }
-            # Is used over .gas().value()
-            if expression.call_gas:
-                call_gas = get(expression.call_gas)
-                message_call.call_gas = call_gas
-            if expression.call_value:
-                call_value = get(expression.call_value)
-                message_call.call_value = call_value
-            if expression.call_salt:
-                call_salt = get(expression.call_salt)
-                message_call.call_salt = call_salt
-            self._result.append(message_call)
-            set_val(expression, val)
+                var = Assignment(val, SolidityVariableComposed('msg.sender'), 'uint256')
+                self._result.append(var)
+                set_val(expression, val)
+            elif called.name == 'origin()':
+                val = TemporaryVariable(self._node)
+                var = Assignment(val, SolidityVariableComposed('tx.origin'), 'uint256')
+                self._result.append(var)
+                set_val(expression, val)
+            elif called.name == 'extcodesize(uint256)':
+                val = ReferenceVariable(self._node)
+                var = Member(args[0], Constant('codesize'), val)
+                self._result.append(var)
+                set_val(expression, val)
+            elif called.name == 'selfbalance()':
+                val = TemporaryVariable(self._node)
+                var = TypeConversion(val, SolidityVariable('this'), ElementaryType('address'))
+                self._result.append(var)
+
+                val1 = ReferenceVariable(self._node)
+                var1 = Member(val, Constant('balance'), val1)
+                self._result.append(var1)
+                set_val(expression, val1)
+            elif called.name == 'address()':
+                val = TemporaryVariable(self._node)
+                var = TypeConversion(val, SolidityVariable('this'), ElementaryType('address'))
+                self._result.append(var)
+                set_val(expression, val)
+            elif called.name == 'callvalue()':
+                val = TemporaryVariable(self._node)
+                var = Assignment(val, SolidityVariableComposed('msg.value'), 'uint256')
+                self._result.append(var)
+                set_val(expression, val)
+            else:
+                # If tuple
+                if expression.type_call.startswith('tuple(') and expression.type_call != 'tuple()':
+                    val = TupleVariable(self._node)
+                else:
+                    val = TemporaryVariable(self._node)
+
+                message_call = TmpCall(called, len(args), val, expression.type_call)
+                message_call.set_expression(expression)
+                # Gas/value are only accessible here if the syntax {gas: , value: }
+                # Is used over .gas().value()
+                if expression.call_gas:
+                    call_gas = get(expression.call_gas)
+                    message_call.call_gas = call_gas
+                if expression.call_value:
+                    call_value = get(expression.call_value)
+                    message_call.call_value = call_value
+                if expression.call_salt:
+                    call_salt = get(expression.call_salt)
+                    message_call.call_salt = call_salt
+                self._result.append(message_call)
+                set_val(expression, val)
 
     def _post_conditional_expression(self, expression):
         raise Exception('Ternary operator are not convertible to SlithIR {}'.format(expression))