From d0968af9a6c02ffd4f18c3c14ba2bcdb988b876a Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Wed, 23 Oct 2013 22:49:02 -0500
Subject: [PATCH] Separate the AST from the parser state.

---
 src/zscript/zcc-parse.lemon | 12 +-----------
 src/zscript/zcc_parser.cpp  | 21 +++++++++++++++++++++
 src/zscript/zcc_parser.h    | 34 +++++++++++++++++++++++-----------
 3 files changed, 45 insertions(+), 22 deletions(-)

diff --git a/src/zscript/zcc-parse.lemon b/src/zscript/zcc-parse.lemon
index a3c9d1141..ae31a1e09 100644
--- a/src/zscript/zcc-parse.lemon
+++ b/src/zscript/zcc-parse.lemon
@@ -2,19 +2,9 @@
 {
 // Allocates a new AST node off the parse state's arena.
 #define NEW_AST_NODE(type,name,tok) \
-	ZCC_##type *name = static_cast<ZCC_##type *>(InitNode(sizeof(ZCC_##type), AST_##type, stat)); \
+	ZCC_##type *name = static_cast<ZCC_##type *>(stat->InitNode(sizeof(ZCC_##type), AST_##type)); \
 	SetNodeLine(name, tok)
 
-static ZCC_TreeNode *InitNode(size_t size, EZCCTreeNodeType type, ZCCParseState *stat)
-{
-	ZCC_TreeNode *node = (ZCC_TreeNode *)stat->SyntaxArena.Alloc(size);
-	node->SiblingNext = node;
-	node->SiblingPrev = node;
-	node->NodeType = type;
-	node->SourceName = stat->Strings.Alloc(stat->sc.ScriptName);
-	return node;
-}
-
 static void SetNodeLine(ZCC_TreeNode *name, ZCCToken &tok)
 {
 	name->SourceLoc = tok.SourceLoc;
diff --git a/src/zscript/zcc_parser.cpp b/src/zscript/zcc_parser.cpp
index 766f28c2a..32127ed46 100644
--- a/src/zscript/zcc_parser.cpp
+++ b/src/zscript/zcc_parser.cpp
@@ -297,3 +297,24 @@ static FString ZCCTokenName(int terminal)
 	}
 	return FScanner::TokenName(sc_token);
 }
+
+ZCC_TreeNode *ZCC_AST::InitNode(size_t size, EZCCTreeNodeType type, ZCC_TreeNode *basis)
+{
+	ZCC_TreeNode *node = (ZCC_TreeNode *)SyntaxArena.Alloc(size);
+	node->SiblingNext = node;
+	node->SiblingPrev = node;
+	node->NodeType = type;
+	if (basis != NULL)
+	{
+		node->SourceName = basis->SourceName;
+		node->SourceLoc = basis->SourceLoc;
+	}
+	return node;
+}
+
+ZCC_TreeNode *ZCCParseState::InitNode(size_t size, EZCCTreeNodeType type)
+{
+	ZCC_TreeNode *node = ZCC_AST::InitNode(size, type, NULL);
+	node->SourceName = Strings.Alloc(sc.ScriptName);
+	return node;
+}
diff --git a/src/zscript/zcc_parser.h b/src/zscript/zcc_parser.h
index f5131e839..50e75fd94 100644
--- a/src/zscript/zcc_parser.h
+++ b/src/zscript/zcc_parser.h
@@ -1,15 +1,7 @@
-struct ZCCParseState
-{
-	ZCCParseState(FScanner &scanner) : sc(scanner)
-	{
-		TopNode = NULL;
-	}
+#ifndef ZCC_PARSER_H
+#define ZCC_PARSER_H
 
-	FScanner &sc;
-	FSharedStringArena Strings;
-	FMemArena SyntaxArena;
-	struct ZCC_TreeNode *TopNode;
-};
+#include "memarena.h"
 
 struct ZCCToken
 {
@@ -500,3 +492,23 @@ struct ZCC_FuncDeclarator : ZCC_Declarator
 };
 
 FString ZCC_PrintAST(ZCC_TreeNode *root);
+
+struct ZCC_AST
+{
+	ZCC_AST() : TopNode(NULL) {}
+	ZCC_TreeNode *InitNode(size_t size, EZCCTreeNodeType type, ZCC_TreeNode *basis);
+
+	FSharedStringArena Strings;
+	FMemArena SyntaxArena;
+	struct ZCC_TreeNode *TopNode;
+};
+
+struct ZCCParseState : public ZCC_AST
+{
+	ZCCParseState(FScanner &scanner) : sc(scanner) {}
+	ZCC_TreeNode *InitNode(size_t size, EZCCTreeNodeType type);
+
+	FScanner &sc;
+};
+
+#endif