Merge pull request #457 from daejunpark/fix-issue-453

fix issue #453

docs/types.rst

@@ -61,7 +61,7 @@ A signed integer (128 bit) is a type to store positive and negative integers.
 
 Values
 ------
-Signed integer values between -2\ :sup:`127` and (2\ :sup:`127` - 1).
+Signed integer values between -2\ :sup:`127` and (2\ :sup:`127` - 1), inclusive.
 
 Operators
 ---------

tests/parser/exceptions/test_invalid_literal_exception.py

@@ -20,7 +20,7 @@ def foo():
     """,
     """
 def foo():
-    x = -170141183460469231731687303715884105728
+    x = -170141183460469231731687303715884105729 # -2**127 - 1
     """,
     """
 def foo():

tests/parser/types/numbers/test_num.py

@@ -1,6 +1,6 @@
 import pytest
 from tests.setup_transaction_tests import chain as s, tester as t, ethereum_utils as u, check_gas, \
-    get_contract_with_gas_estimation, get_contract
+    get_contract_with_gas_estimation, get_contract, assert_tx_failed
 
 def test_exponents_with_nums():
     exp_code = """
@@ -16,3 +16,55 @@ def _num_exp(x: num, y: num) -> num:
     assert c._num_exp(3,3) == 27
     assert c._num_exp(72,19) == 72**19
 
+def test_nagative_nums(assert_tx_failed):
+    negative_nums_code = """
+def _negative_num() -> num:
+    return -1
+def _negative_exp() -> num:
+    return -(1+2)
+    """
+
+    c = get_contract(negative_nums_code)
+    t.s = s
+    assert c._negative_num() == -1
+    assert c._negative_exp() == -3
+
+def test_num_bound(assert_tx_failed):
+    num_bound_code = """
+def _num(x: num) -> num:
+    return x
+
+def _num_add(x: num, y: num) -> num:
+    return x + y
+
+def _num_sub(x: num, y: num) -> num:
+    return x - y
+
+def _num_add3(x: num, y: num, z: num) -> num:
+    return x + y + z
+
+def _num_max() -> num:
+    return  170141183460469231731687303715884105727   #  2**127 - 1
+
+def _num_min() -> num:
+    return -170141183460469231731687303715884105728   # -2**127
+    """
+
+    c = get_contract(num_bound_code)
+
+    t.s = s
+    NUM_MAX =  2**127 - 1
+    NUM_MIN = -2**127
+    assert c._num_add(NUM_MAX, 0) == NUM_MAX
+    assert c._num_sub(NUM_MIN, 0) == NUM_MIN
+    assert c._num_add(NUM_MAX - 1, 1) == NUM_MAX
+    assert c._num_sub(NUM_MIN + 1, 1) == NUM_MIN
+    assert_tx_failed(lambda: c._num_add(NUM_MAX, 1))
+    assert_tx_failed(lambda: c._num_sub(NUM_MIN, 1))
+    assert_tx_failed(lambda: c._num_add(NUM_MAX - 1, 2))
+    assert_tx_failed(lambda: c._num_sub(NUM_MIN + 1, 2))
+    assert c._num_max() == NUM_MAX
+    assert c._num_min() == NUM_MIN
+
+    assert_tx_failed(lambda: c._num_add3(NUM_MAX, 1, -1))
+    assert c._num_add3(NUM_MAX, -1, 1) == NUM_MAX

viper/functions.py

@@ -185,8 +185,6 @@ def as_num256(expr, args, kwargs, context):
             raise InvalidLiteralException("Number out of range: " + str(expr.args[0].n), expr.args[0])
         return LLLnode.from_list(args[0], typ=BaseType('num256', None), pos=getpos(expr))
     elif isinstance(args[0], LLLnode):
-        if args[0].value == "sub" and args[0].args[0].value == 0 and args[0].args[1].value > 0:
-            raise InvalidLiteralException("Negative numbers cannot be num256 literals")
         return LLLnode(value=args[0].value, args=args[0].args, typ=BaseType('num256'), pos=getpos(expr))
     else:
         raise InvalidLiteralException("Invalid input for num256: %r" % args[0], expr)

viper/parser/expr.py

@@ -17,6 +17,7 @@
 )
 from viper.utils import (
     MemoryPositions,
+    SizeLimits,
     bytes_to_int,
     string_to_bytes,
     DECIMAL_DIVISOR,
@@ -78,7 +79,7 @@ def get_expr(self):
     def number(self):
         orignum = get_original_if_0x_prefixed(self.expr, self.context)
         if orignum is None and isinstance(self.expr.n, int):
-            if not (-2**127 + 1 <= self.expr.n <= 2**127 - 1):
+            if not (SizeLimits.MINNUM <= self.expr.n <= SizeLimits.MAXNUM):
                 raise InvalidLiteralException("Number out of range: " + str(self.expr.n), self.expr)
             return LLLnode.from_list(self.expr.n, typ=BaseType('num', None), pos=getpos(self.expr))
         elif isinstance(self.expr.n, float):

viper/parser/parser.py

@@ -60,13 +60,15 @@
 def parse(code):
     o = ast.parse(code)
     decorate_ast_with_source(o, code)
+    o = resolve_negative_literals(o)
     return o.body
 
 
 # Parser for a single line
 def parse_line(code):
     o = ast.parse(code).body[0]
     decorate_ast_with_source(o, code)
+    o = resolve_negative_literals(o)
     return o
 
 
@@ -82,6 +84,19 @@ def visit(self, node):
     MyVisitor().visit(_ast)
 
 
+def resolve_negative_literals(_ast):
+
+    class RewriteUnaryOp(ast.NodeTransformer):
+        def visit_UnaryOp(self, node):
+            if isinstance(node.op, ast.USub) and isinstance(node.operand, ast.Num):
+                node.operand.n = 0 - node.operand.n
+                return node.operand
+            else:
+                return node
+
+    return RewriteUnaryOp().visit(_ast)
+
+
 # Make a getter for a variable. This function gives an output that
 # contains lists of 4-tuples:
 # (i) the tail of the function name for the getter