icode: Globals and locals with explicit types

Closes #78.

icode.py

@@ -4,7 +4,8 @@
 from nodes import (
     FuncDef, IntExpr, MypyFile, ReturnStmt, NameExpr, WhileStmt,
     AssignmentStmt, Node, Var, OpExpr, Block, CallExpr, IfStmt, ParenExpr,
-    UnaryExpr, ExpressionStmt, CoerceExpr, TypeDef, MemberExpr, TypeInfo
+    UnaryExpr, ExpressionStmt, CoerceExpr, TypeDef, MemberExpr, TypeInfo,
+    VarDef
 )
 import nodes
 from visitor import NodeVisitor
@@ -414,6 +415,18 @@ class IcodeBuilder(NodeVisitor<int>):
             stmt.accept(self)
         return -1
 
+    int visit_var_def(self, VarDef d):
+        assert len(d.items) == 1
+        var = d.items[0][0]
+        if d.kind == nodes.LDEF:
+            reg = self.add_local(var)
+            if d.init:
+                self.accept(d.init, reg)
+        elif d.kind == nodes.GDEF and d.init:
+            init = self.accept(d.init)
+            self.add(SetGR(var.full_name(), init))
+        return -1
+
     int visit_expression_stmt(self, ExpressionStmt s):
         self.accept(s.expr)
         return -1

test/data/cgen-basic.test

@@ -105,6 +105,30 @@ void f():
     print(j)  # 0
 f()
 
+[case testLocalWithExplicitType]
+class A: pass
+void f():
+    int x = 2
+    print(x) # 2
+    int y
+    print(y) # 0
+    y = 3
+    print(y) # 3
+    A a
+    print(a) # None
+f()
+
+[case testGlobalWithExplicitType]
+class A: pass
+int x = 2
+print(x) # 2
+int y
+print(y) # 0
+y = 3
+print(y) # 3
+A a
+print(a) # None
+
 -- TODO
 --   integer overflows and underflows
 --   stack overflow

test/data/icode-basic.test

@@ -357,3 +357,30 @@ L1:
 L2:
     r1 = None
     return r1
+
+[case testLocalWithExplicitType]
+void f():
+    int x = 2
+    int y
+    y = 3
+    A a
+[out]
+def f:
+    r0 = 2
+    r1 = 3
+    r2 = None
+    return r2
+
+[case testGlobalWithExplicitType]
+class A: pass
+int x = 2
+int y
+y = 3
+[out]
+def __init:
+    r0 = 2
+    __main__.x = r0
+    r1 = 3
+    __main__.y = r1
+    r2 = None
+    return r2