def _op(self, left, right): if not right: raise ZeroDivisionException("Modulo by zero") value = abs(left) % abs(right) if left < 0: value = -value return value
def types_from_BinOp(self, node): # binary operation: `x + y` types_list = get_common_types(node.left, node.right) if (isinstance(node.op, (vy_ast.Div, vy_ast.Mod)) and isinstance(node.right, vy_ast.Num) and not node.right.value): raise ZeroDivisionException(f"{node.op.description} by zero", node) return _validate_op(node, types_list, "validate_numeric_op")
def _op(self, left, right): # evaluate the operation using true division or floor division assert type(left) is type(right) if not right: raise ZeroDivisionException("Division by zero") if isinstance(left, decimal.Decimal): value = left / right if value < 0: # the EVM always truncates toward zero value = -(-left / right) # ensure that the result is truncated at 10 decimal places return value.quantize(decimal.Decimal("1.0000000000"), decimal.ROUND_DOWN) else: value = left // right if value < 0: return -(-left // right) return value
def arithmetic(self): left = Expr.parse_value_expr(self.expr.left, self.context) right = Expr.parse_value_expr(self.expr.right, self.context) if not is_numeric_type(left.typ) or not is_numeric_type(right.typ): raise TypeMismatch( f"Unsupported types for arithmetic op: {left.typ} {right.typ}", self.expr, ) arithmetic_pair = {left.typ.typ, right.typ.typ} pos = getpos(self.expr) # Special case with uint256 were int literal may be casted. if arithmetic_pair == {'uint256', 'int128'}: # Check right side literal. if right.typ.is_literal and SizeLimits.in_bounds( 'uint256', right.value): right = LLLnode.from_list( right.value, typ=BaseType('uint256', None, is_literal=True), pos=pos, ) # Check left side literal. elif left.typ.is_literal and SizeLimits.in_bounds( 'uint256', left.value): left = LLLnode.from_list( left.value, typ=BaseType('uint256', None, is_literal=True), pos=pos, ) if left.typ.typ == "decimal" and isinstance(self.expr.op, vy_ast.Pow): raise TypeMismatch( "Cannot perform exponentiation on decimal values.", self.expr, ) # Only allow explicit conversions to occur. if left.typ.typ != right.typ.typ: raise TypeMismatch( f"Cannot implicitly convert {left.typ.typ} to {right.typ.typ}.", self.expr, ) ltyp, rtyp = left.typ.typ, right.typ.typ if isinstance(self.expr.op, (vy_ast.Add, vy_ast.Sub)): new_typ = BaseType(ltyp) op = 'add' if isinstance(self.expr.op, vy_ast.Add) else 'sub' if ltyp == 'uint256' and isinstance(self.expr.op, vy_ast.Add): # safeadd arith = [ 'seq', ['assert', ['ge', ['add', 'l', 'r'], 'l']], ['add', 'l', 'r'] ] elif ltyp == 'uint256' and isinstance(self.expr.op, vy_ast.Sub): # safesub arith = [ 'seq', ['assert', ['ge', 'l', 'r']], ['sub', 'l', 'r'] ] elif ltyp == rtyp: arith = [op, 'l', 'r'] else: raise Exception( f"Unsupported Operation '{op}({ltyp}, {rtyp})'") elif isinstance(self.expr.op, vy_ast.Mult): new_typ = BaseType(ltyp) if ltyp == rtyp == 'uint256': arith = [ 'with', 'ans', ['mul', 'l', 'r'], [ 'seq', [ 'assert', [ 'or', ['eq', ['div', 'ans', 'l'], 'r'], ['iszero', 'l'] ] ], 'ans' ] ] elif ltyp == rtyp == 'int128': # TODO should this be 'smul' (note edge cases in YP for smul) arith = ['mul', 'l', 'r'] elif ltyp == rtyp == 'decimal': # TODO should this be smul arith = [ 'with', 'ans', ['mul', 'l', 'r'], [ 'seq', [ 'assert', [ 'or', ['eq', ['sdiv', 'ans', 'l'], 'r'], ['iszero', 'l'] ] ], ['sdiv', 'ans', DECIMAL_DIVISOR] ] ] else: raise Exception(f"Unsupported Operation 'mul({ltyp}, {rtyp})'") elif isinstance(self.expr.op, vy_ast.Div): if right.typ.is_literal and right.value == 0: raise ZeroDivisionException("Cannot divide by 0.", self.expr) new_typ = BaseType(ltyp) if ltyp == rtyp == 'uint256': arith = ['div', 'l', ['clamp_nonzero', 'r']] elif ltyp == rtyp == 'int128': arith = ['sdiv', 'l', ['clamp_nonzero', 'r']] elif ltyp == rtyp == 'decimal': arith = [ 'sdiv', # TODO check overflow cases, also should it be smul ['mul', 'l', DECIMAL_DIVISOR], ['clamp_nonzero', 'r'] ] else: raise Exception(f"Unsupported Operation 'div({ltyp}, {rtyp})'") elif isinstance(self.expr.op, vy_ast.Mod): if right.typ.is_literal and right.value == 0: raise ZeroDivisionException("Cannot calculate modulus of 0.", self.expr) new_typ = BaseType(ltyp) if ltyp == rtyp == 'uint256': arith = ['mod', 'l', ['clamp_nonzero', 'r']] elif ltyp == rtyp: # TODO should this be regular mod arith = ['smod', 'l', ['clamp_nonzero', 'r']] else: raise Exception(f"Unsupported Operation 'mod({ltyp}, {rtyp})'") elif isinstance(self.expr.op, vy_ast.Pow): if ltyp != 'int128' and ltyp != 'uint256' and isinstance( self.expr.right, vy_ast.Name): raise TypeMismatch( "Cannot use dynamic values as exponents, for unit base types", self.expr, ) new_typ = BaseType(ltyp) if ltyp == rtyp == 'uint256': arith = [ 'seq', [ 'assert', [ 'or', # r == 1 | iszero(r) # could be simplified to ~(r & 1) ['or', ['eq', 'r', 1], ['iszero', 'r']], ['lt', 'l', ['exp', 'l', 'r']] ] ], ['exp', 'l', 'r'] ] elif ltyp == rtyp == 'int128': arith = ['exp', 'l', 'r'] else: raise TypeMismatch('Only whole number exponents are supported', self.expr) else: raise StructureException( f"Unsupported binary operator: {self.expr.op}", self.expr) p = ['seq'] if new_typ.typ == 'int128': p.append([ 'clamp', ['mload', MemoryPositions.MINNUM], arith, ['mload', MemoryPositions.MAXNUM], ]) elif new_typ.typ == 'decimal': p.append([ 'clamp', ['mload', MemoryPositions.MINDECIMAL], arith, ['mload', MemoryPositions.MAXDECIMAL], ]) elif new_typ.typ == 'uint256': p.append(arith) else: raise Exception(f"{arith} {new_typ}") p = ['with', 'l', left, ['with', 'r', right, p]] return LLLnode.from_list(p, typ=new_typ, pos=pos)
def arithmetic(self): left = Expr.parse_value_expr(self.expr.left, self.context) right = Expr.parse_value_expr(self.expr.right, self.context) if not is_numeric_type(left.typ) or not is_numeric_type(right.typ): raise TypeMismatchException( f"Unsupported types for arithmetic op: {left.typ} {right.typ}", self.expr, ) arithmetic_pair = {left.typ.typ, right.typ.typ} # Special Case: Simplify any literal to literal arithmetic at compile time. if left.typ.is_literal and right.typ.is_literal and \ isinstance(right.value, int) and isinstance(left.value, int) and \ arithmetic_pair.issubset({'uint256', 'int128'}): if isinstance(self.expr.op, vy_ast.Add): val = left.value + right.value elif isinstance(self.expr.op, vy_ast.Sub): val = left.value - right.value elif isinstance(self.expr.op, vy_ast.Mult): val = left.value * right.value elif isinstance(self.expr.op, vy_ast.Pow): val = left.value ** right.value elif isinstance(self.expr.op, (vy_ast.Div, vy_ast.Mod)): if right.value == 0: raise ZeroDivisionException( "integer division or modulo by zero", self.expr, ) if isinstance(self.expr.op, vy_ast.Div): val = left.value // right.value elif isinstance(self.expr.op, vy_ast.Mod): # modified modulo logic to remain consistent with EVM behaviour val = abs(left.value) % abs(right.value) if left.value < 0: val = -val else: raise ParserException( f'Unsupported literal operator: {type(self.expr.op)}', self.expr, ) num = vy_ast.Int(n=val) num.full_source_code = self.expr.full_source_code num.node_source_code = self.expr.node_source_code num.lineno = self.expr.lineno num.col_offset = self.expr.col_offset num.end_lineno = self.expr.end_lineno num.end_col_offset = self.expr.end_col_offset return Expr.parse_value_expr(num, self.context) pos = getpos(self.expr) # Special case with uint256 were int literal may be casted. if arithmetic_pair == {'uint256', 'int128'}: # Check right side literal. if right.typ.is_literal and SizeLimits.in_bounds('uint256', right.value): right = LLLnode.from_list( right.value, typ=BaseType('uint256', None, is_literal=True), pos=pos, ) # Check left side literal. elif left.typ.is_literal and SizeLimits.in_bounds('uint256', left.value): left = LLLnode.from_list( left.value, typ=BaseType('uint256', None, is_literal=True), pos=pos, ) if left.typ.typ == "decimal" and isinstance(self.expr.op, vy_ast.Pow): raise TypeMismatchException( "Cannot perform exponentiation on decimal values.", self.expr, ) # Only allow explicit conversions to occur. if left.typ.typ != right.typ.typ: raise TypeMismatchException( f"Cannot implicitly convert {left.typ.typ} to {right.typ.typ}.", self.expr, ) ltyp, rtyp = left.typ.typ, right.typ.typ if isinstance(self.expr.op, (vy_ast.Add, vy_ast.Sub)): if left.typ.unit != right.typ.unit and left.typ.unit != {} and right.typ.unit != {}: raise TypeMismatchException( f"Unit mismatch: {left.typ.unit} {right.typ.unit}", self.expr, ) if ( left.typ.positional and right.typ.positional and isinstance(self.expr.op, vy_ast.Add) ): raise TypeMismatchException( "Cannot add two positional units!", self.expr, ) new_unit = left.typ.unit or right.typ.unit # xor, as subtracting two positionals gives a delta new_positional = left.typ.positional ^ right.typ.positional new_typ = BaseType(ltyp, new_unit, new_positional) op = 'add' if isinstance(self.expr.op, vy_ast.Add) else 'sub' if ltyp == 'uint256' and isinstance(self.expr.op, vy_ast.Add): # safeadd arith = ['seq', ['assert', ['ge', ['add', 'l', 'r'], 'l']], ['add', 'l', 'r']] elif ltyp == 'uint256' and isinstance(self.expr.op, vy_ast.Sub): # safesub arith = ['seq', ['assert', ['ge', 'l', 'r']], ['sub', 'l', 'r']] elif ltyp == rtyp: arith = [op, 'l', 'r'] else: raise Exception(f"Unsupported Operation '{op}({ltyp}, {rtyp})'") elif isinstance(self.expr.op, vy_ast.Mult): if left.typ.positional or right.typ.positional: raise TypeMismatchException("Cannot multiply positional values!", self.expr) new_unit = combine_units(left.typ.unit, right.typ.unit) new_typ = BaseType(ltyp, new_unit) if ltyp == rtyp == 'uint256': arith = ['with', 'ans', ['mul', 'l', 'r'], ['seq', ['assert', ['or', ['eq', ['div', 'ans', 'l'], 'r'], ['iszero', 'l']]], 'ans']] elif ltyp == rtyp == 'int128': # TODO should this be 'smul' (note edge cases in YP for smul) arith = ['mul', 'l', 'r'] elif ltyp == rtyp == 'decimal': # TODO should this be smul arith = ['with', 'ans', ['mul', 'l', 'r'], ['seq', ['assert', ['or', ['eq', ['sdiv', 'ans', 'l'], 'r'], ['iszero', 'l']]], ['sdiv', 'ans', DECIMAL_DIVISOR]]] else: raise Exception(f"Unsupported Operation 'mul({ltyp}, {rtyp})'") elif isinstance(self.expr.op, vy_ast.Div): if right.typ.is_literal and right.value == 0: raise ZeroDivisionException("Cannot divide by 0.", self.expr) if left.typ.positional or right.typ.positional: raise TypeMismatchException("Cannot divide positional values!", self.expr) new_unit = combine_units(left.typ.unit, right.typ.unit, div=True) new_typ = BaseType(ltyp, new_unit) if ltyp == rtyp == 'uint256': arith = ['div', 'l', ['clamp_nonzero', 'r']] elif ltyp == rtyp == 'int128': arith = ['sdiv', 'l', ['clamp_nonzero', 'r']] elif ltyp == rtyp == 'decimal': arith = ['sdiv', # TODO check overflow cases, also should it be smul ['mul', 'l', DECIMAL_DIVISOR], ['clamp_nonzero', 'r']] else: raise Exception(f"Unsupported Operation 'div({ltyp}, {rtyp})'") elif isinstance(self.expr.op, vy_ast.Mod): if right.typ.is_literal and right.value == 0: raise ZeroDivisionException("Cannot calculate modulus of 0.", self.expr) if left.typ.positional or right.typ.positional: raise TypeMismatchException( "Cannot use positional values as modulus arguments!", self.expr, ) if not are_units_compatible(left.typ, right.typ) and not (left.typ.unit or right.typ.unit): # noqa: E501 raise TypeMismatchException("Modulus arguments must have same unit", self.expr) new_unit = left.typ.unit or right.typ.unit new_typ = BaseType(ltyp, new_unit) if ltyp == rtyp == 'uint256': arith = ['mod', 'l', ['clamp_nonzero', 'r']] elif ltyp == rtyp: # TODO should this be regular mod arith = ['smod', 'l', ['clamp_nonzero', 'r']] else: raise Exception(f"Unsupported Operation 'mod({ltyp}, {rtyp})'") elif isinstance(self.expr.op, vy_ast.Pow): if left.typ.positional or right.typ.positional: raise TypeMismatchException( "Cannot use positional values as exponential arguments!", self.expr, ) if right.typ.unit: raise TypeMismatchException( "Cannot use unit values as exponents", self.expr, ) if ltyp != 'int128' and ltyp != 'uint256' and isinstance(self.expr.right, vy_ast.Name): raise TypeMismatchException( "Cannot use dynamic values as exponents, for unit base types", self.expr, ) new_unit = left.typ.unit if left.typ.unit and not isinstance(self.expr.right, vy_ast.Name): new_unit = {left.typ.unit.copy().popitem()[0]: self.expr.right.n} new_typ = BaseType(ltyp, new_unit) if ltyp == rtyp == 'uint256': arith = ['seq', ['assert', ['or', # r == 1 | iszero(r) # could be simplified to ~(r & 1) ['or', ['eq', 'r', 1], ['iszero', 'r']], ['lt', 'l', ['exp', 'l', 'r']]]], ['exp', 'l', 'r']] elif ltyp == rtyp == 'int128': arith = ['exp', 'l', 'r'] else: raise TypeMismatchException('Only whole number exponents are supported', self.expr) else: raise ParserException(f"Unsupported binary operator: {self.expr.op}", self.expr) p = ['seq'] if new_typ.typ == 'int128': p.append([ 'clamp', ['mload', MemoryPositions.MINNUM], arith, ['mload', MemoryPositions.MAXNUM], ]) elif new_typ.typ == 'decimal': p.append([ 'clamp', ['mload', MemoryPositions.MINDECIMAL], arith, ['mload', MemoryPositions.MAXDECIMAL], ]) elif new_typ.typ == 'uint256': p.append(arith) else: raise Exception(f"{arith} {new_typ}") p = ['with', 'l', left, ['with', 'r', right, p]] return LLLnode.from_list(p, typ=new_typ, pos=pos)