grep: print "filename:lineno:" in invalid-regex diagnostic

Determining the file name and line number is a little tricky because
of the way the regular expressions are all concatenated onto a newline-
separated list.  By the time grep would compile regular expressions,
the <filename,lineno> origin of each regexp was no longer available.
This patch adds a list of filename,first_lineno pairs, one per input
source, by which we can then map the ordinal regexp number to a
filename,lineno pair for the diagnostic.

* src/dfasearch.c (GEAcompile): When diagnosing an invalid regexp
specified via -f FILE, include the "FILENAME:LINENO: " prefix.
Also, when there are two or more lines with compilation failures,
diagnose all of them, rather than stopping after the first.
* src/grep.h (pattern_file_name): Declare it.
* src/grep.c: (struct FL_pair): Define type.
(fl_pair, n_fl_pair_slots, n_pattern_files, patfile_lineno):
Define globals.
(fl_add, pattern_file_name): Define functions.
(main): Call fl_add for each type of the following: -e argument,
-f argument, command-line-specified (without -e) regexp.
* tests/filename-lineno.pl: New file.
* tests/Makefile.am (TESTS): Add it.
* NEWS (Improvements): Mention this.
Initially reported by Gunnar Wolf in https://bugs.debian.org/525214
Forwarded to grep's bug list by Santiago Ruano Rincón as
http://debbugs.gnu.org/23965

1 files changed, 80 insertions, 0 deletions

diff --git a/tests/filename-lineno.pl b/tests/filename-lineno.pl
new file mode 100755
index 00000000..3827f4da
--- /dev/null
+++ b/tests/filename-lineno.pl
@@ -0,0 +1,80 @@
+#!/usr/bin/perl
+# Prior to 2.26, an invalid regexp in a -f-specified file would elicit
+# a diagnostic like "Unmatched [ or [^", with no indication of the
+# file or line number from which the offending regular expression came.
+# With 2.26, now, each such diagnostic has a "FILENAME:LINENO: " prefix.
+
+# Copyright (C) 2016 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+use strict;
+
+(my $program_name = $0) =~ s|.*/||;
+
+my $prog = 'grep';
+
+# Turn off localization of executable's output.
+@ENV{qw(LANGUAGE LANG LC_ALL)} = ('C') x 3;
+
+# There are at least two variants of one diagnostic:
+#   - Unmatched [, [^, [:, [., or [=
+#   - Unmatched [ or [^
+# Transform each to this: "Unmatched [..."
+my $err_subst = {ERR_SUBST => 's/(: Unmatched \[).*/$1.../'};
+
+my @Tests =
+  (
+   # Show that grep now includes filename:lineno in the diagnostic:
+   ['invalid-re', '-f g', {AUX=>{g=>"1\n2\n3\n4[[\n"}}, {EXIT=>2},
+    $err_subst,
+    {ERR => "$prog: g:4: Unmatched [...\n"},
+   ],
+
+   # Show that with two or more errors, grep now prints all diagnostics:
+   ['invalid-re-2-files', '-f g -f h', {EXIT=>2},
+    {AUX=>{g=>"1\n2[[\n3\n4[[\n"}},
+    {AUX=>{h=>"\n\n[[\n"}},
+    $err_subst,
+    {ERR => "$prog: g:2: Unmatched [...\n"
+         . "$prog: g:4: Unmatched [...\n"
+         . "$prog: h:3: Unmatched [...\n"
+    },
+   ],
+
+   # Like the above, but on the other lines.
+   ['invalid-re-2-files2', '-f g -f h', {EXIT=>2},
+    {AUX=>{g=>"1[[\n2\n3[[\n4\n"}},
+    {AUX=>{h=>"[[\n[[\n\n"}},
+    $err_subst,
+    {ERR => "$prog: g:1: Unmatched [...\n"
+         . "$prog: g:3: Unmatched [...\n"
+         . "$prog: h:1: Unmatched [...\n"
+         . "$prog: h:2: Unmatched [...\n"
+    },
+   ],
+
+   # Show that with two '-e'-specified erroneous regexps,
+   # there is no file name or line number.
+   ['invalid-re-2e', '-e "[[" -e "[["', {EXIT=>2},
+    $err_subst,
+    {ERR => "$prog: Unmatched [...\n" x 2},
+   ],
+  );
+
+my $save_temps = $ENV{DEBUG};
+my $verbose = $ENV{VERBOSE};
+
+my $fail = run_tests ($program_name, $prog, \@Tests, $save_temps, $verbose);
+exit $fail;