From 1c42c18e9601ee1416d61663f5a91874954c524d Mon Sep 17 00:00:00 2001
From: Brian Foley <bpfoley@google.com>
Date: Sun, 6 Jan 2019 18:32:59 -0800
Subject: [PATCH] awk: Fix overly permissive func arg list parsing
It allows things like 'func f(a b)' and 'func f(a,)' which GNU awk forbids.
function old new delta
parse_program 327 367 +40
chain_expr 40 67 +27
parse_expr 891 915 +24
EMSG_TOO_FEW_ARGS 30 18 -12
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/1 up/down: 91/-12) Total: 79 bytes
Signed-off-by: Brian Foley <bpfoley@google.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---
editors/awk.c | 15 ++++++++++++++-
testsuite/awk.tests | 12 ++++++++++++
2 files changed, 26 insertions(+), 1 deletion(-)
diff --git a/editors/awk.c b/editors/awk.c
index 90edec82c..d25508e5d 100644
--- a/editors/awk.c
+++ b/editors/awk.c
@@ -1613,12 +1613,25 @@ static void parse_program(char *p)
f = newfunc(t_string);
f->body.first = NULL;
f->nargs = 0;
- while (next_token(TC_VARIABLE | TC_SEQTERM) & TC_VARIABLE) {
+ /* Match func arg list: a comma sep list of >= 0 args, and a close paren */
+ while (next_token(TC_VARIABLE | TC_SEQTERM | TC_COMMA)) {
+ /* Either an empty arg list, or trailing comma from prev iter
+ * must be followed by an arg */
+ if (f->nargs == 0 && t_tclass == TC_SEQTERM)
+ break;
+
+ /* TC_SEQSTART/TC_COMMA must be followed by TC_VARIABLE */
+ if (t_tclass != TC_VARIABLE)
+ syntax_error(EMSG_UNEXP_TOKEN);
+
v = findvar(ahash, t_string);
v->x.aidx = f->nargs++;
+ /* Arg followed either by end of arg list or 1 comma */
if (next_token(TC_COMMA | TC_SEQTERM) & TC_SEQTERM)
break;
+ if (t_tclass != TC_COMMA)
+ syntax_error(EMSG_UNEXP_TOKEN);
}
seq = &f->body;
chain_group();
diff --git a/testsuite/awk.tests b/testsuite/awk.tests
index 03fedf771..0db6a26e4 100755
--- a/testsuite/awk.tests
+++ b/testsuite/awk.tests
@@ -280,6 +280,18 @@ testing "awk 'delete a[v--]' evaluates v-- once" \
" \
"" ""
+testing "awk func arg parsing 1" \
+ "awk 'func f(,) { }' 2>&1" "awk: cmd. line:1: Unexpected token\n" "" ""
+
+testing "awk func arg parsing 2" \
+ "awk 'func f(a,,b) { }' 2>&1" "awk: cmd. line:1: Unexpected token\n" "" ""
+
+testing "awk func arg parsing 3" \
+ "awk 'func f(a,) { }' 2>&1" "awk: cmd. line:1: Unexpected token\n" "" ""
+
+testing "awk func arg parsing 4" \
+ "awk 'func f(a b) { }' 2>&1" "awk: cmd. line:1: Unexpected token\n" "" ""
+
testing "awk handles empty ()" \
"awk 'BEGIN {print()}' 2>&1" "awk: cmd. line:1: Empty sequence\n" "" ""
--
2.25.1