From 1ef20f9e52551d6cdca02ecd9bc829bdb859c7f7 Mon Sep 17 00:00:00 2001
From: Peter Wu <lekensteyn@gmail.com>
Date: Sat, 3 Dec 2011 11:28:39 +0000
Subject: Process function declarations to avoid "undefined function" warnings

---
 Function.py   | 23 ++++++++++++++++++++---
 LinkedNode.py |  1 +
 pp2cc.py      | 12 ++++++++----
 3 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/Function.py b/Function.py
index de0c49d..38d01ea 100644
--- a/Function.py
+++ b/Function.py
@@ -19,10 +19,19 @@ __maintainer__ = "Peter Wu"
 __email__ = "uwretep@gmail.com"
 
 class Function(object):
-    def __init__(self, node):
-        self.name = node.decl.name
-        self.node = node
+    def __init__(self, decl_node):
+        """Initializes an object for holding a function declaration and related
+        properties
+
+        Keyword arguments:
+        decl_node -- A Node object 
+        """
+        assert type(decl_node).__name__ == "FuncDecl", ("decl_node is not a"
+                                                        " function declaration")
+        self.decl_node = decl_node
+        self.name = self.decl_node.type.declname
         self.reserved_stack = 0
+        self.linked_node = None
     def labelBegin(self):
         """Returns a label pointing to the begin of a function"""
         return "fn_" + self.name
@@ -40,3 +49,11 @@ class Function(object):
         begin_address = self.reserved_stack + 1
         self.reserved_stack += count
         return begin_address
+    def setLinkedNode(self, linked_node):
+        """Assigns this function to a function node"""
+        assert linked_node.type == "FuncDef", ("Only function definitions can"
+                                               " be linked to a function")
+        self.linked_node = linked_node
+    def isLinked(self):
+        """Returns True if this function object is already linked to a node"""
+        return self.linked_node is not None
diff --git a/LinkedNode.py b/LinkedNode.py
index f068993..b24812a 100644
--- a/LinkedNode.py
+++ b/LinkedNode.py
@@ -101,6 +101,7 @@ class LinkedNode(object):
         allocation function
         """
         self.function = function
+        function.setLinkedNode(self)
         self.variables.setFunction(function)
     def getLocation(self):
         if hasattr(self.node, "coord"):
diff --git a/pp2cc.py b/pp2cc.py
index 4c83afb..8f6a581 100755
--- a/pp2cc.py
+++ b/pp2cc.py
@@ -201,11 +201,14 @@ class Parse(object):
         linked_node.incrementLevel()
         self.asm.level = linked_node.level
 
+        # parse function declaration (which will parse params as well)
+        assert not self.parseStatement(node.decl, linked_node), ("Function"
+            " declaration should not return a line of assembly")
         funcname = node.decl.name
-        if funcname in self.functions:
+        function = self.functions[funcname]
+        if function.isLinked():
             self.logger.error("Redefinition of function '{}'".format(funcname),
                               linked_node=linked_node)
-        function = self.functions[funcname] = Function(node)
 
         lbl_func = function.labelBegin()
         lbl_end = function.labelEnd()
@@ -215,8 +218,6 @@ class Parse(object):
         # save Base Pointer
         lines = [self.asm.push(self.registers.BP, lbl_func)]
         lines.append(self.asm.binary_op("LOAD", self.registers.BP, "SP"))
-        # parse function declaration (which will parse params as well)
-        lines += self.parseStatement(node.decl, linked_node)
 
         body = self.parseStatement(node.body, linked_node)
         self.asm.level = linked_node.level
@@ -1211,6 +1212,9 @@ class Parse(object):
     def parseFuncDecl(self, linked_node):
         lines = []
         node = linked_node.node
+        funcname = node.type.declname
+        if not funcname in self.functions:
+            self.functions[funcname] = Function(node)
         if node.args:
             argstype = type(node.args).__name__
             assert argstype == "ParamList", "Expected function arguments, found '{}' instead".format(argstype)
-- 
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