Support for loops

1 files changed, 30 insertions, 3 deletions

diff --git a/pp2cc.py b/pp2cc.py
index 38858d1..c050cf6 100755
--- a/pp2cc.py
+++ b/pp2cc.py
@@ -725,6 +725,35 @@ class Parse(object):
         # }
         lines.append(self.asm.noop(lbl_while_end))
         return lines
+    def parseFor(self, linked_node):
+        """Returns ASM for a for loop
+        
+        for (init; cond; next) { body; } is equivalent to:
+        init; while (cond) { body; next; }
+        Note that for (;;){} is allowed too which is equivalent to:
+        while (true) {}
+        """
+        node = linked_node.node
+        lines = []
+        lbl_for = self.uniqLbl("for")
+        lbl_for_end = self.uniqLbl("forEnd")
+
+        if node.init: # init;
+            lines += self.parseStatement(node.init, linked_node)
+        # while (
+        lines.append(self.asm.noop(lbl_for))
+        if node.cond: # if no condition, it's should evaluate to true
+            lines += self.parseStatement(node.cond, linked_node)
+            lines.append(self.asm.branch_op("BEQ", lbl_for_end))
+        # ){ body;
+        lines += self.parseStatement(node.stmt, linked_node)
+        if node.next: # next;
+            lines += self.parseStatement(node.next, linked_node)
+
+        lines.append(self.asm.branch_op("BRA", lbl_for))
+        # }
+        lines.append(self.asm.noop(lbl_for_end))
+        return lines
     def parseStatement(self, node, parent_linked_node, level_increment=False):
         linked_node = LinkedNode(node, parent_linked_node, level_increment=level_increment)
         self.asm.level = linked_node.level
@@ -735,8 +764,6 @@ class Parse(object):
             self.defineGlobalVar(linked_node, parent_linked_node)
         elif isinstance(node, c_ast.ExprList):
             raise RuntimeError("Not implemented for type " + repr(node))
-        elif isinstance(node, c_ast.For):
-            raise RuntimeError("Not implemented for type " + repr(node))
         elif isinstance(node, c_ast.FuncDecl):
             raise RuntimeError("Not implemented for type " + repr(node))
         elif isinstance(node, c_ast.PtrDecl):
@@ -744,7 +771,7 @@ class Parse(object):
         else:
             for entry in ("Compound", "BinaryOp", "If", "Constant", "ID",
                           "Return", "FuncCall", "UnaryOp", "Cast",
-                          "TernaryOp", "DoWhile", "While"):
+                          "TernaryOp", "DoWhile", "While", "For"):
                 if isinstance(node, getattr(c_ast, entry)):
                     lines += getattr(self, "parse" + entry)(linked_node)
                     break