From 1c42c18e9601ee1416d61663f5a91874954c524d Mon Sep 17 00:00:00 2001 From: Brian Foley 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 Signed-off-by: Denys Vlasenko --- 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