Support for array reference (both assignment and rvalue), update README

1 files changed, 24 insertions, 6 deletions

diff --git a/pp2cc.py b/pp2cc.py
index 11ff592..6e6e614 100755
--- a/pp2cc.py
+++ b/pp2cc.py
@@ -1131,8 +1131,12 @@ class Parse(object):
 
         linked_lval = LinkedNode(node.lvalue, linked_node)
         # this lvalue may be an expression if there is an indirection
-        if isinstance(node.lvalue, c_ast.UnaryOp) and node.lvalue.op == "*":
-            lvalue = self.parseExpression(linked_lval.node.expr, linked_lval)
+        if (linked_lval.type == "UnaryOp" and node.lvalue.op == "*" or
+            linked_lval.type == "ArrayRef"):
+            if linked_lval.type == "UnaryOp":
+                lvalue = self.parseExpression(linked_lval.node.expr, linked_lval)
+            else:
+                lvalue = self.parseExpression(linked_lval.node, linked_node)
             lvalue_result_reg = self.registers.find_register(lvalue)
             for line in lvalue:
                 # if the right value register is modified, we need to pull
@@ -1186,14 +1190,24 @@ class Parse(object):
         linked_type = LinkedNode(linked_node.node.type, linked_node)
         var_name = linked_node.variables.declName(linked_node.node.name, 1)
         if linked_type.type == "ArrayDecl":
-            size = self.determineConstValue(LinkedNode(linked_type.node.dim,
+            if linked_type.node.dim is not None:
+                size = self.determineConstValue(LinkedNode(linked_type.node.dim,
                                                        linked_node))
+            else:
+                size = None
             node_init = linked_node.node.init
+            # determine the array dimension based on the initializer
             if node_init and isinstance(node_init, c_ast.ExprList):
                 real_size = len(node_init.exprs)
-                if real_size > size:
+                if size is None:
+                    size = real_size
+                elif real_size > size:
                     self.logger.warning("excess elements in array initializer",
                                         linked_node=linked_node)
+            # it's an error if the array dimension is unavailable, e.g.:
+            # int a[];
+            if size is None:
+                raise RuntimeError("Array size missing in '{}'".format(var_name))
             var_array = linked_node.variables.declName(var_name, size,
                                                        prefix="arr")
         elif linked_type.type == "PtrDecl":
@@ -1332,8 +1346,12 @@ class Parse(object):
         else:
             lines += index_expr
 
-        lines.append(self.asm.binary_op("LOAD", name_reg,
-                                        "[" + name_reg + "+" + index_reg + "]"))
+        if (linked_node.parent and linked_node.parent.type == "Assignment" and
+            linked_node.parent.node.lvalue is linked_node.node):
+            lines.append(self.asm.binary_op("ADD", name_reg, index_reg))
+        else:
+            lines.append(self.asm.binary_op("LOAD", name_reg,
+                                            "[" + name_reg + "+" + index_reg + "]"))
         return lines
     def parseLabel(self, linked_node):
         lines = []