"Scalar found where operator expected" on printing to indirect filehandle within s///e #16847
Comments
From @CorionCreated by corion@corion.netThis is a bug report for perl from corion@corion.net, ----------------------------------------------------------------- last week I (together with E. Choroba) stumbled on a weird syntax perl -wle "s/(.*)/print $fh $1/e" This surprisingly gives a syntax error, yet still seems to run the code: Scalar found where operator expected at -e line 1, near "$fh $1" The code even outputs 'foo' in the below version: perl -wle "my $fh = \*STDOUT; $_ = ''; s//print $fh 'foo'/e" The "fix" for this (highly unconventional) code is to use curly brackets perl -wle "my $fh = \*STDOUT; $_ = ''; s//print {$fh} 'foo'/e" I still think that the original code should parse without error, even Perl Info |
From @tonycozOn Fri, 15 Feb 2019 11:37:16 -0800, corion@corion.net wrote:
This isn't a syntax error, but a warning (but still buggy). The code inside the replacement part of s///e is handled with a sublex, and the code that decides whether an operator or term is expected after C<print $fh> is mostly skipped for a sublex. The attached fixes that, doing the same checks for C<print $fh> in a sublex within brackets as for a normal parse. This fixes the same problem for C<< "... ${code} ..." >>. Tony |
From @tonycoz0001-perl-133850-fix-parsing-hints-for-print-fh-foo-in-s-.patchFrom 9e0f09ef2afa82ef1a96cba981d4fca094bba484 Mon Sep 17 00:00:00 2001
From: Tony Cook <tony@develop-help.com>
Date: Tue, 19 Feb 2019 15:38:39 +1100
Subject: (perl #133850) fix parsing hints for print $fh "foo" in s///e
The replacement code in s///e is parsed using a sublex, similarly
to double-quotish replacement.
The code that handles C< $id > tries to detect what the next token
should be, but only special cased code similar to C< print $fh ... >
in a non-sublex, so s/../print $fh $1/e set PL_expect to XOPERATOR
which caused the parser to complain when the $1 wasn't an operator.
The fix here handles two cases:
s/.../code here/e
In this case the code is inserted into a do {} block like:
do { code here }
so PL_lex_brackets ends up non-zero.
The second case is code like:
"xxx${code here}"
which had the same problem, which this also fixes.
---
t/lib/warnings/toke | 14 ++++++++++++++
toke.c | 2 +-
2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/t/lib/warnings/toke b/t/lib/warnings/toke
index 1c85d7bc44..a500856283 100644
--- a/t/lib/warnings/toke
+++ b/t/lib/warnings/toke
@@ -1675,3 +1675,17 @@ Execution of - aborted due to compilation errors.
use utf8;
qw���foo ��� ��� bar���
EXPECT
+########
+# NAME [perl #133850] print $fh $1 in s///e expression
+use warnings;
+my $fh = \*STDOUT;
+$_ = "abc";
+s/(x)/ print $fh $1 /e;
+EXPECT
+########
+# NAME [perl #133850] side case
+use warnings;
+my $fh = \*STDOUT;
+my $y = "";
+my $x = "${print $fh $y; \'x'}";
+EXPECT
diff --git a/toke.c b/toke.c
index 5a3fe78472..0eb63fcb55 100644
--- a/toke.c
+++ b/toke.c
@@ -6772,7 +6772,7 @@ Perl_yylex(pTHX)
}
PL_expect = XOPERATOR;
- if (PL_lex_state == LEX_NORMAL && isSPACE((char)tmp)) {
+ if ((PL_lex_state == LEX_NORMAL || PL_lex_brackets) && isSPACE((char)tmp)) {
const bool islop = (PL_last_lop == PL_oldoldbufptr);
if (!islop || PL_last_lop_op == OP_GREPSTART)
PL_expect = XOPERATOR;
--
2.11.0
|
|
The RT System itself - Status changed from 'new' to 'open' |
From @tonycozOn Mon, 18 Feb 2019 20:44:26 -0800, tonyc wrote:
There's some other similar cases - i.e. where PL_lex_state is checked for LEX_NORMAL but no other checks are made. The simplest I was able to reproduce was: $ ./perl -we '%x = qw(a b c d); $_ = ""; $_ = @x {a}' Kind of unlikely: tony@mars:.../git/perl$ ./perl -Ilib -we '{ my $x : shared = 1; }' Another: $ ./perl -we '$a = ${time}' Tony |
From @tonycozOn Mon, 18 Feb 2019 20:44:26 -0800, tonyc wrote:
Rebased on blead, and fixes for the related issues. I'll apply this in a few days. Tony |
From @tonycozsubparse-tokens.patchFrom cb43f46efc62573c3470f5c2de01ee0e5b6ffd4a Mon Sep 17 00:00:00 2001
From: Tony Cook <tony@develop-help.com>
Date: Tue, 19 Feb 2019 15:38:39 +1100
Subject: (perl #133850) fix parsing hints for print $fh "foo" in s///e
The replacement code in s///e is parsed using a sublex, similarly
to double-quotish replacement.
The code that handles C< $id > tries to detect what the next token
should be, but only special cased code similar to C< print $fh ... >
in a non-sublex, so s/../print $fh $1/e set PL_expect to XOPERATOR
which caused the parser to complain when the $1 wasn't an operator.
The fix here handles two cases:
s/.../code here/e
In this case the code is inserted into a do {} block like:
do { code here }
so PL_lex_brackets ends up non-zero.
The second case is code like:
"xxx${code here}"
which had the same problem, which this also fixes.
---
t/lib/warnings/toke | 14 ++++++++++++++
toke.c | 2 +-
2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/t/lib/warnings/toke b/t/lib/warnings/toke
index 83641e5106..944e5d92f4 100644
--- a/t/lib/warnings/toke
+++ b/t/lib/warnings/toke
@@ -1691,3 +1691,17 @@ EXPECT
OPTION regex
Malformed UTF-8 character: .*non-continuation.*
The eval did not crash the program
+########
+# NAME [perl #133850] print $fh $1 in s///e expression
+use warnings;
+my $fh = \*STDOUT;
+$_ = "abc";
+s/(x)/ print $fh $1 /e;
+EXPECT
+########
+# NAME [perl #133850] side case
+use warnings;
+my $fh = \*STDOUT;
+my $y = "";
+my $x = "${print $fh $y; \'x'}";
+EXPECT
diff --git a/toke.c b/toke.c
index b0fa2c35ba..dc376f6beb 100644
--- a/toke.c
+++ b/toke.c
@@ -6838,7 +6838,7 @@ Perl_yylex(pTHX)
}
PL_expect = XOPERATOR;
- if (PL_lex_state == LEX_NORMAL && isSPACE((char)tmp)) {
+ if ((PL_lex_state == LEX_NORMAL || PL_lex_brackets) && isSPACE((char)tmp)) {
const bool islop = (PL_last_lop == PL_oldoldbufptr);
if (!islop || PL_last_lop_op == OP_GREPSTART)
PL_expect = XOPERATOR;
--
2.11.0
From 2b67caa9b5055eb7441998a9538af722639982af Mon Sep 17 00:00:00 2001
From: Tony Cook <tony@develop-help.com>
Date: Wed, 29 May 2019 11:46:01 +1000
Subject: (perl #133850) warn on ${time} even in sub-parse
Code like:
$a = ${time}
warns with:
Ambiguous use of ${time} resolved to $time at ...
but:
s/^/ ${time} /e
didn't, since the parser is in a special state in sub-parses.
---
t/lib/warnings/toke | 8 ++++++++
toke.c | 2 +-
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/t/lib/warnings/toke b/t/lib/warnings/toke
index 944e5d92f4..eab22fbbc9 100644
--- a/t/lib/warnings/toke
+++ b/t/lib/warnings/toke
@@ -1705,3 +1705,11 @@ my $fh = \*STDOUT;
my $y = "";
my $x = "${print $fh $y; \'x'}";
EXPECT
+########
+# NAME [perl #133850] another case
+use warnings;
+my $time = 1;
+$_ = "";
+s/^/ ${time} /e
+EXPECT
+Ambiguous use of ${time} resolved to $time at - line 4.
diff --git a/toke.c b/toke.c
index dc376f6beb..c42d4fd802 100644
--- a/toke.c
+++ b/toke.c
@@ -9660,7 +9660,7 @@ S_scan_ident(pTHX_ char *s, char *dest, STRLEN destlen, I32 ck_uni)
PL_lex_state = LEX_INTERPEND;
PL_expect = XREF;
}
- if (PL_lex_state == LEX_NORMAL) {
+ if (PL_lex_state == LEX_NORMAL || PL_lex_brackets) {
if (ckWARN(WARN_AMBIGUOUS)
&& (keyword(dest, d - dest, 0)
|| get_cvn_flags(dest, d - dest, is_utf8
--
2.11.0
From f623089c7b47c9de58667b70063be135948356bd Mon Sep 17 00:00:00 2001
From: Tony Cook <tony@develop-help.com>
Date: Wed, 29 May 2019 13:47:36 +1000
Subject: (perl #133850) allow @x{...} with space in sub-parse
---
t/lib/warnings/toke | 8 ++++++++
toke.c | 2 +-
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/t/lib/warnings/toke b/t/lib/warnings/toke
index eab22fbbc9..5dbef1ab62 100644
--- a/t/lib/warnings/toke
+++ b/t/lib/warnings/toke
@@ -1713,3 +1713,11 @@ $_ = "";
s/^/ ${time} /e
EXPECT
Ambiguous use of ${time} resolved to $time at - line 4.
+########
+# NAME [perl #133850] another case
+use warnings;
+%x = qw(a b c d);
+$_ = "";
+s/^/ @x {a} /e
+EXPECT
+Scalar value @x{"a"} better written as $x{"a"} at - line 4.
diff --git a/toke.c b/toke.c
index c42d4fd802..e1b163334f 100644
--- a/toke.c
+++ b/toke.c
@@ -6911,7 +6911,7 @@ Perl_yylex(pTHX)
if (!PL_tokenbuf[1]) {
PREREF('@');
}
- if (PL_lex_state == LEX_NORMAL)
+ if (PL_lex_state == LEX_NORMAL || PL_lex_brackets)
s = skipspace(s);
if ( (PL_expect != XREF || PL_oldoldbufptr == PL_last_lop)
&& intuit_more(s, PL_bufend))
--
2.11.0
From d50d49c97634fa03d472f06bf4e70fe7dfc17fd2 Mon Sep 17 00:00:00 2001
From: Tony Cook <tony@develop-help.com>
Date: Wed, 29 May 2019 14:37:25 +1000
Subject: (perl #133850) allow attributes in sub-parses
---
t/op/attrs.t | 3 +++
toke.c | 2 +-
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/t/op/attrs.t b/t/op/attrs.t
index 649525ce22..dd230b3fbd 100644
--- a/t/op/attrs.t
+++ b/t/op/attrs.t
@@ -507,4 +507,7 @@ BEGIN failed--compilation aborted at - line 1.
EOS
"attribute on our hash with sub of same name");
+fresh_perl_is('$_ = ""; s/^/ { my $x : shared = 1; } /e;', "", {},
+ "attributes in sub-parse");
+
done_testing();
diff --git a/toke.c b/toke.c
index e1b163334f..0b3b76fee3 100644
--- a/toke.c
+++ b/toke.c
@@ -5991,7 +5991,7 @@ Perl_yylex(pTHX)
switch (PL_expect) {
case XOPERATOR:
- if (!PL_in_my || PL_lex_state != LEX_NORMAL)
+ if (!PL_in_my || (PL_lex_state != LEX_NORMAL && !PL_lex_brackets))
break;
PL_bufptr = s; /* update in case we back off */
if (*s == '=') {
--
2.11.0
|
From @tonycozOn Tue, 28 May 2019 22:08:50 -0700, tonyc wrote:
Applied as eec8822 through 82de236. Tony |
|
@tonycoz - Status changed from 'open' to 'pending release' |
Migrated from rt.perl.org#133850 (status was 'pending release')
Searchable as RT133850$
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