py/emitnative: Implement viper unary ops positive, negative and invert.

Signed-off-by: Damien George <damien@micropython.org>

tests/micropython/viper_error.py

@@ -50,6 +50,9 @@ def f():
 # incorrect return type
 test("@micropython.viper\ndef f() -> int: return []")
 
+# can't do unary op of incompatible type
+test("@micropython.viper\ndef f(x:ptr): -x")
+
 # can't do binary op between incompatible types
 test("@micropython.viper\ndef f(): 1 + []")
 test("@micropython.viper\ndef f(x:int, y:uint): x < y")
@@ -69,9 +72,7 @@ test("@micropython.viper\ndef f(x:ptr32): x[x] = None")
 test("@micropython.viper\ndef f(): raise 1")
 
 # unary ops not implemented
-test("@micropython.viper\ndef f(x:int): +x")
-test("@micropython.viper\ndef f(x:int): -x")
-test("@micropython.viper\ndef f(x:int): ~x")
+test("@micropython.viper\ndef f(x:int): not x")
 
 # binary op not implemented
 test("@micropython.viper\ndef f(x:uint, y:uint): res = x // y")

tests/micropython/viper_error.py.exp

@@ -5,6 +5,7 @@ ViperTypeError("local 'x' used before type known",)
 ViperTypeError("local 'x' has type 'int' but source is 'object'",)
 ViperTypeError("can't implicitly convert 'ptr' to 'bool'",)
 ViperTypeError("return expected 'int' but got 'object'",)
+ViperTypeError("can't do unary op of 'ptr'",)
 ViperTypeError("can't do binary op between 'int' and 'object'",)
 ViperTypeError('comparison of int and uint',)
 ViperTypeError("can't load from 'int'",)
@@ -15,9 +16,7 @@ ViperTypeError("can't store to 'int'",)
 ViperTypeError("can't store 'None'",)
 ViperTypeError("can't store 'None'",)
 ViperTypeError('must raise an object',)
-ViperTypeError('unary op __pos__ not implemented',)
-ViperTypeError('unary op __neg__ not implemented',)
-ViperTypeError('unary op __invert__ not implemented',)
+ViperTypeError("'not' not implemented",)
 ViperTypeError('div/mod not implemented for uint',)
 ViperTypeError('div/mod not implemented for uint',)
 ViperTypeError('binary op  not implemented',)

tests/micropython/viper_unop.py

@@ -0,0 +1,31 @@
+# test unary operators
+
+
+@micropython.viper
+def pos(x: int) -> int:
+    return +x
+
+
+print(pos(0))
+print(pos(1))
+print(pos(-2))
+
+
+@micropython.viper
+def neg(x: int) -> int:
+    return -x
+
+
+print(neg(0))
+print(neg(1))
+print(neg(-2))
+
+
+@micropython.viper
+def inv(x: int) -> int:
+    return ~x
+
+
+print(inv(0))
+print(inv(1))
+print(inv(-2))

tests/micropython/viper_unop.py.exp

@@ -0,0 +1,9 @@
+0
+1
+-2
+0
+-1
+2
+-1
+-2
+1