From 0fd82b60cff02f1fe2a74d820902bd1fc4667d7b Mon Sep 17 00:00:00 2001
From: Tor Andersson <tor.andersson@artifex.com>
Date: Mon, 18 Jan 2016 13:33:03 +0100
Subject: [PATCH] Make js_try, js_savetry and js_endtry public
 functions/macros.

---
 jsi.h   | 10 ++--------
 jsrun.c | 23 ++++++++++++++++++++++-
 mujs.h  |  9 +++++++++
 3 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/jsi.h b/jsi.h
index 40821e9..08ee5fd 100644
--- a/jsi.h
+++ b/jsi.h
@@ -117,16 +117,10 @@ struct js_Jumpbuf
 	js_Instruction *pc;
 };
 
-void js_savetry(js_State *J, js_Instruction *pc);
+void *js_savetrypc(js_State *J, js_Instruction *pc);
 
 #define js_trypc(J, PC) \
-	setjmp((js_savetry(J, PC), J->trybuf[J->trytop++].buf))
-
-#define js_try(J) \
-	setjmp((js_savetry(J, NULL), J->trybuf[J->trytop++].buf))
-
-#define js_endtry(J) \
-	(--J->trytop)
+	setjmp(js_savetrypc(J, PC))
 
 /* State struct */
 
diff --git a/jsrun.c b/jsrun.c
index abacf11..c44cf6d 100644
--- a/jsrun.c
+++ b/jsrun.c
@@ -1144,7 +1144,7 @@ int js_pcall(js_State *J, int n)
 
 /* Exceptions */
 
-void js_savetry(js_State *J, js_Instruction *pc)
+void *js_savetrypc(js_State *J, js_Instruction *pc)
 {
 	if (J->trytop == JS_TRYLIMIT)
 		js_error(J, "try: exception stack overflow");
@@ -1154,6 +1154,27 @@ void js_savetry(js_State *J, js_Instruction *pc)
 	J->trybuf[J->trytop].top = J->top;
 	J->trybuf[J->trytop].bot = J->bot;
 	J->trybuf[J->trytop].pc = pc;
+	return J->trybuf[J->trytop++].buf;
+}
+
+void *js_savetry(js_State *J)
+{
+	if (J->trytop == JS_TRYLIMIT)
+		js_error(J, "try: exception stack overflow");
+	J->trybuf[J->trytop].E = J->E;
+	J->trybuf[J->trytop].envtop = J->envtop;
+	J->trybuf[J->trytop].tracetop = J->tracetop;
+	J->trybuf[J->trytop].top = J->top;
+	J->trybuf[J->trytop].bot = J->bot;
+	J->trybuf[J->trytop].pc = NULL;
+	return J->trybuf[J->trytop++].buf;
+}
+
+void js_endtry(js_State *J)
+{
+	if (J->trytop == 0)
+		js_error(J, "endtry: exception stack underflow");
+	--J->trytop;
 }
 
 void js_throw(js_State *J)
diff --git a/mujs.h b/mujs.h
index c1d66c8..3b8169c 100644
--- a/mujs.h
+++ b/mujs.h
@@ -48,6 +48,15 @@ int js_ploadfile(js_State *J, const char *filename);
 int js_pcall(js_State *J, int n);
 int js_pconstruct(js_State *J, int n);
 
+/* Exception handling */
+
+void *js_savetry(js_State *J); /* returns a jmp_buf */
+
+#define js_try(J) \
+	setjmp(js_savetry(J))
+
+void js_endtry(js_State *J);
+
 /* State constructor flags */
 enum {
 	JS_STRICT = 1,