From 9650392e04a54e2e8fdf0e41f03b3bbd668f0239 Mon Sep 17 00:00:00 2001
From: Tor Andersson <tor@ccxvii.net>
Date: Sat, 18 Jan 2014 17:19:31 +0100
Subject: [PATCH] Return value of last evaluated expression in eval and script
 code.

Patch in a return statement at the end of such code.
---
 jsdump.c  |  2 +-
 jsparse.c | 15 ++++++++++++++-
 jsparse.h |  3 +--
 3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/jsdump.c b/jsdump.c
index 7d2e2d0..cfe00c1 100644
--- a/jsdump.c
+++ b/jsdump.c
@@ -6,7 +6,7 @@
 #include <assert.h>
 
 static const char *astname[] = {
-	"list", "ident", "number", "string", "regexp", "fundec", "undef",
+	"list", "fundec", "ident", "number", "string", "regexp", "undef",
 	"null", "true", "false", "this", "fun", "array", "object", "prop_val",
 	"prop_get", "prop_set", "index", "member", "call", "new", "delete",
 	"void", "typeof", "preinc", "predec", "postinc", "postdec", "pos",
diff --git a/jsparse.c b/jsparse.c
index a372ecc..75dc021 100644
--- a/jsparse.c
+++ b/jsparse.c
@@ -864,6 +864,8 @@ int jsP_error(js_State *J, const char *fmt, ...)
 
 js_Ast *jsP_parse(js_State *J, const char *filename, const char *source)
 {
+	js_Ast *p, *last;
+
 	jsP_initlex(J, filename, source);
 
 	if (setjmp(J->jb)) {
@@ -872,5 +874,16 @@ js_Ast *jsP_parse(js_State *J, const char *filename, const char *source)
 	}
 
 	next(J);
-	return script(J);
+	p = script(J);
+
+	/* patch up global and eval code to return value of last expression */
+	last = p;
+	if (last) {
+		while (last->b)
+			last = last->b;
+		if (last->a->type >= AST_IDENTIFIER && last->a->type < STM_BLOCK)
+			last->a = STM1(RETURN, last->a);
+	}
+
+	return p;
 }
diff --git a/jsparse.h b/jsparse.h
index d715382..7667b22 100644
--- a/jsparse.h
+++ b/jsparse.h
@@ -4,14 +4,13 @@
 enum
 {
 	AST_LIST,
+	AST_FUNDEC,
 
 	AST_IDENTIFIER,
 	AST_NUMBER,
 	AST_STRING,
 	AST_REGEXP,
 
-	AST_FUNDEC,
-
 	/* literals */
 	EXP_UNDEF, /* for array elisions */
 	EXP_NULL,