From 2437fadedf898de68fdbd9653056275b823025e3 Mon Sep 17 00:00:00 2001
From: hyung-hwan <hyunghwan.chung@gmail.com>
Date: Wed, 10 Apr 2024 19:48:49 +0900
Subject: [PATCH] fixed the compiler to check the presense of the exception
 handler expression in the catch part

---
 lib/comp.c      | 7 +++++++
 lib/prim.c      | 4 ++--
 lib/print.c     | 2 +-
 t/call-5001.err | 4 ++++
 4 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/lib/comp.c b/lib/comp.c
index 68305ad..3df15ed 100644
--- a/lib/comp.c
+++ b/lib/comp.c
@@ -3533,6 +3533,13 @@ static HCL_INLINE int compile_catch (hcl_t* hcl)
 	HCL_ASSERT (hcl, fbi->tmpr_nargs + fbi->tmpr_nrvars + fbi->tmpr_nlvars == fbi->tmprcnt - par_tmprcnt);
 
 	obj = HCL_CNODE_CONS_CDR(obj);
+	if (!obj)
+	{
+		/* the error message is no exception handler. but what is expected is an expression.
+		 * e.g. a number, nil, a block expression, etc */
+		hcl_setsynerrbfmt (hcl, HCL_SYNERR_NOVALUE, HCL_CNODE_GET_LOC(exarg), HCL_NULL, "no exception handler after %.*js", HCL_CNODE_GET_TOKLEN(cmd), HCL_CNODE_GET_TOKPTR(cmd));
+		return -1;
+	}
 
 	/* jump_inst_pos hold the instruction pointer that skips the catch block at the end of the try block */
 	patch_nearest_post_try (hcl, &jump_inst_pos);
diff --git a/lib/prim.c b/lib/prim.c
index e5d8a1d..d9eb6d8 100644
--- a/lib/prim.c
+++ b/lib/prim.c
@@ -300,7 +300,7 @@ static hcl_pfrc_t pf_nqk (hcl_t* hcl, hcl_mod_t* mod, hcl_ooi_t nargs)
 
 /* ------------------------------------------------------------------------- */
 
-static hcl_pfrc_t pf_is_null (hcl_t* hcl, hcl_mod_t* mod, hcl_ooi_t nargs)
+static hcl_pfrc_t pf_is_nil (hcl_t* hcl, hcl_mod_t* mod, hcl_ooi_t nargs)
 {
 	hcl_oop_t rv;
 	rv = (HCL_STACK_GETARG(hcl, nargs, 0) == hcl->_nil)? hcl->_true: hcl->_false;
@@ -924,7 +924,7 @@ static pf_t builtin_prims[] =
 	{ 2, 2,                       pf_nql,             4,  { 'n','q','l','?' } },
 	{ 2, 2,                       pf_nqk,             4,  { 'n','q','k','?' } },
 
-	{ 1, 1,                       pf_is_null,         5,  { 'n','u','l','l','?' } },
+	{ 1, 1,                       pf_is_nil,          4,  { 'n','i','l','?' } },
 	{ 1, 1,                       pf_is_boolean,      8,  { 'b','o','o','l','e','a','n','?' } },
 	{ 1, 1,                       pf_is_character,   10,  { 'c','h','a','r','a','c','t','e','r','?' } },
 	{ 1, 1,                       pf_is_error,        6,  { 'e','r','r','o','r','?' } },
diff --git a/lib/print.c b/lib/print.c
index 0466dea..50925ce 100644
--- a/lib/print.c
+++ b/lib/print.c
@@ -102,7 +102,7 @@ static struct
 } word[] =
 {
 	{  8,  { '#','<','U','N','D','E','F','>' } },
-	{  4,  { 'n','u','l','l' } },
+	{  3,  { 'n','i','l' } },
 	{  4,  { 't','r','u','e' } },
 	{  5,  { 'f','a','l','s','e' } },
 
diff --git a/t/call-5001.err b/t/call-5001.err
index ab11e79..e018463 100644
--- a/t/call-5001.err
+++ b/t/call-5001.err
@@ -9,3 +9,7 @@ try {
 } catch (e a) { ##ERROR: syntax error - not proper exception variable
 	printf "EXCEPTION - %s\n" e
 }
+
+---
+
+try { throw "1111"; } catch (e) ##ERROR: syntax error - no exception handler