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awk: Fix overly permissive func arg list parsing

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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>
This commit is contained in:
Brian Foley 2019-01-06 18:32:59 -08:00 committed by Denys Vlasenko
parent 08a514c097
commit 1c42c18e96
2 changed files with 26 additions and 1 deletions
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15
editors/awk.c
View File

@ -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();

12
testsuite/awk.tests
View File

@ -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" "" ""