Patchwork libio: use stdout in puts and putchar, etc [BZ #24051].

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Submitter Paul Pluzhnikov
Date Jan. 2, 2019, 8:34 p.m.
Message ID <CALoOobOzXze3Ncu8FHhJwjttQnssrXG=XwS1gd=N7Cfgk=vadw@mail.gmail.com>
Download mbox | patch
Permalink /patch/30945/
State New
Headers show

Comments

Paul Pluzhnikov - Jan. 2, 2019, 8:34 p.m.
Greetings,

This fixes the output part of BZ #24051 for narrow and wide streams.
The test is slightly asymmetric: as far as I can tell a wide
equivalent to puts() doesn't exist.

I'll work on fixing the similar stdin problem in a follow-up.

Thanks,
Florian Weimer - Jan. 3, 2019, 1:08 p.m.
* Paul Pluzhnikov:

> diff --git a/libio/tst-bz24051.c b/libio/tst-bz24051.c
> new file mode 100644
> index 0000000000..52c7a64b5b
> --- /dev/null
> +++ b/libio/tst-bz24051.c
> @@ -0,0 +1,79 @@

> +/* Prevent putchar -> _IO_putc inline expansion.  */
> +#define __NO_INLINE__

#pragma GCC optimize ("O0") seems prudent here as well, to inhibit any
printf uptimizations.

> +  rewind (stdout);
> +  TEST_VERIFY_EXIT (fgetws (buf, sizeof (buf), stdout) != NULL);
> +  TEST_VERIFY (wcscmp (buf, L"abcdef") == 0);

You should use array_length (buf) here (and include <array_length.h>).
fgetws does not expect a ybte byte count.

Rest of the patch looks okay to me.  (Siddhesh needs to ack this because
of the freeze.)

Thanks,
Florian
Siddhesh Poyarekar - Jan. 3, 2019, 1:17 p.m.
On 03/01/19 6:38 PM, Florian Weimer wrote:
> * Paul Pluzhnikov:
> 
>> diff --git a/libio/tst-bz24051.c b/libio/tst-bz24051.c
>> new file mode 100644
>> index 0000000000..52c7a64b5b
>> --- /dev/null
>> +++ b/libio/tst-bz24051.c
>> @@ -0,0 +1,79 @@
> 
>> +/* Prevent putchar -> _IO_putc inline expansion.  */
>> +#define __NO_INLINE__
> 
> #pragma GCC optimize ("O0") seems prudent here as well, to inhibit any
> printf uptimizations.
> 
>> +  rewind (stdout);
>> +  TEST_VERIFY_EXIT (fgetws (buf, sizeof (buf), stdout) != NULL);
>> +  TEST_VERIFY (wcscmp (buf, L"abcdef") == 0);
> 
> You should use array_length (buf) here (and include <array_length.h>).
> fgetws does not expect a ybte byte count.
> 
> Rest of the patch looks okay to me.  (Siddhesh needs to ack this because
> of the freeze.)

Fine from the freeze perspective, but this needs a more descriptive 
commit description.

Siddhesh

Patch

diff --git a/ChangeLog b/ChangeLog
index 75c80e6f02..70c6176f6a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@ 
+2019-01-02  Paul Pluzhnikov  <ppluzhnikov@google.com>
+
+	[BZ #24051]
+	* libio/ioputs.c (_IO_puts): Use stdout instead of _IO_stdout.
+	* libio/fileops.c (_IO_new_file_underflow): Likewise
+	* libio/wfileops.c (_IO_wfile_underflow): Likewise
+	* libio/putchar.c (putchar): Likewise.
+	* libio/putchar_u.c (putchar_unlocked): Likewise.
+	* libio/putwchar.c (putchar): Likewise.
+	* libio/putwchar_u.c (putwchar_unlocked): Likewise.
+	* libio/tst-bz24051.c: New test.
+	* libio/Makefile (tests): Add tst-bz24051
+
 2019-01-02  Joseph Myers  <joseph@codesourcery.com>
 
 	* sysdeps/unix/sysv/linux/tst-mman-consts.py (main): Expect
diff --git a/libio/Makefile b/libio/Makefile
index 5bee83e55c..dbeba88fc0 100644
--- a/libio/Makefile
+++ b/libio/Makefile
@@ -65,7 +65,7 @@  tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc   \
 	tst-setvbuf1 tst-popen1 tst-fgetwc bug-wsetpos tst-fseek \
 	tst-fwrite-error tst-ftell-partial-wide tst-ftell-active-handler \
 	tst-ftell-append tst-fputws tst-bz22415 tst-fgetc-after-eof \
-	tst-sprintf-ub tst-sprintf-chk-ub
+	tst-sprintf-ub tst-sprintf-chk-ub tst-bz24051
 
 tests-internal = tst-vtables tst-vtables-interposed tst-readline
 
diff --git a/libio/fileops.c b/libio/fileops.c
index 43e33820e3..d2070a856e 100644
--- a/libio/fileops.c
+++ b/libio/fileops.c
@@ -501,13 +501,13 @@  _IO_new_file_underflow (FILE *fp)
 	 traditional Unix systems did this for stdout.  stderr better
 	 not be line buffered.  So we do just that here
 	 explicitly.  --drepper */
-      _IO_acquire_lock (_IO_stdout);
+      _IO_acquire_lock (stdout);
 
-      if ((_IO_stdout->_flags & (_IO_LINKED | _IO_NO_WRITES | _IO_LINE_BUF))
+      if ((stdout->_flags & (_IO_LINKED | _IO_NO_WRITES | _IO_LINE_BUF))
 	  == (_IO_LINKED | _IO_LINE_BUF))
-	_IO_OVERFLOW (_IO_stdout, EOF);
+	_IO_OVERFLOW (stdout, EOF);
 
-      _IO_release_lock (_IO_stdout);
+      _IO_release_lock (stdout);
     }
 
   _IO_switch_to_get_mode (fp);
diff --git a/libio/ioputs.c b/libio/ioputs.c
index 04ae323c6d..319e551de5 100644
--- a/libio/ioputs.c
+++ b/libio/ioputs.c
@@ -33,15 +33,15 @@  _IO_puts (const char *str)
 {
   int result = EOF;
   size_t len = strlen (str);
-  _IO_acquire_lock (_IO_stdout);
+  _IO_acquire_lock (stdout);
 
-  if ((_IO_vtable_offset (_IO_stdout) != 0
-       || _IO_fwide (_IO_stdout, -1) == -1)
-      && _IO_sputn (_IO_stdout, str, len) == len
-      && _IO_putc_unlocked ('\n', _IO_stdout) != EOF)
+  if ((_IO_vtable_offset (stdout) != 0
+       || _IO_fwide (stdout, -1) == -1)
+      && _IO_sputn (stdout, str, len) == len
+      && _IO_putc_unlocked ('\n', stdout) != EOF)
     result = MIN (INT_MAX, len + 1);
 
-  _IO_release_lock (_IO_stdout);
+  _IO_release_lock (stdout);
   return result;
 }
 
diff --git a/libio/putchar.c b/libio/putchar.c
index 665f46685a..a3f4200cdb 100644
--- a/libio/putchar.c
+++ b/libio/putchar.c
@@ -24,9 +24,9 @@  int
 putchar (int c)
 {
   int result;
-  _IO_acquire_lock (_IO_stdout);
-  result = _IO_putc_unlocked (c, _IO_stdout);
-  _IO_release_lock (_IO_stdout);
+  _IO_acquire_lock (stdout);
+  result = _IO_putc_unlocked (c, stdout);
+  _IO_release_lock (stdout);
   return result;
 }
 
diff --git a/libio/putchar_u.c b/libio/putchar_u.c
index 37d03ad364..1eebf0fc8f 100644
--- a/libio/putchar_u.c
+++ b/libio/putchar_u.c
@@ -23,6 +23,6 @@ 
 int
 putchar_unlocked (int c)
 {
-  CHECK_FILE (_IO_stdout, EOF);
-  return _IO_putc_unlocked (c, _IO_stdout);
+  CHECK_FILE (stdout, EOF);
+  return _IO_putc_unlocked (c, stdout);
 }
diff --git a/libio/putwchar.c b/libio/putwchar.c
index 8d6b6a4df0..1f5c4176f8 100644
--- a/libio/putwchar.c
+++ b/libio/putwchar.c
@@ -22,8 +22,8 @@  wint_t
 putwchar (wchar_t wc)
 {
   wint_t result;
-  _IO_acquire_lock (_IO_stdout);
-  result = _IO_putwc_unlocked (wc, _IO_stdout);
-  _IO_release_lock (_IO_stdout);
+  _IO_acquire_lock (stdout);
+  result = _IO_putwc_unlocked (wc, stdout);
+  _IO_release_lock (stdout);
   return result;
 }
diff --git a/libio/putwchar_u.c b/libio/putwchar_u.c
index cfb46fc253..d943220031 100644
--- a/libio/putwchar_u.c
+++ b/libio/putwchar_u.c
@@ -21,6 +21,6 @@ 
 wint_t
 putwchar_unlocked (wchar_t wc)
 {
-  CHECK_FILE (_IO_stdout, WEOF);
-  return _IO_putwc_unlocked (wc, _IO_stdout);
+  CHECK_FILE (stdout, WEOF);
+  return _IO_putwc_unlocked (wc, stdout);
 }
diff --git a/libio/tst-bz24051.c b/libio/tst-bz24051.c
new file mode 100644
index 0000000000..52c7a64b5b
--- /dev/null
+++ b/libio/tst-bz24051.c
@@ -0,0 +1,79 @@ 
+/* Test that assigning to stdout redirects puts, putchar, etc (BZ#24051)
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+
+/* Prevent putchar -> _IO_putc inline expansion.  */
+#define __NO_INLINE__
+
+#include <stdio.h>
+#include <string.h>
+#include <wchar.h>
+
+#include <support/check.h>
+#include <support/temp_file.h>
+#include <support/test-driver.h>
+
+#undef putchar
+#undef putwchar
+
+static int
+do_test_narrow (void)
+{
+  char buf[100];
+  int fd = create_temp_file ("tst-bz24051", NULL);
+  stdout = fdopen (fd, "w+");
+  TEST_VERIFY_EXIT (stdout != NULL);
+
+  printf ("ab%s", "cd");
+  putchar ('e');
+  putchar_unlocked ('f');
+  puts ("ghi");
+
+  rewind (stdout);
+  TEST_VERIFY_EXIT (fgets (buf, sizeof (buf), stdout) != NULL);
+  TEST_VERIFY (strcmp (buf, "abcdefghi\n") == 0);
+
+  return 0;
+}
+
+static int
+do_test_wide (void)
+{
+  wchar_t buf[100];
+  int fd = create_temp_file ("tst-bz24051w", NULL);
+  stdout = fdopen (fd, "w+");
+  TEST_VERIFY_EXIT (stdout != NULL);
+
+  wprintf (L"ab%ls", L"cd");
+  putwchar (L'e');
+  putwchar_unlocked (L'f');
+
+  rewind (stdout);
+  TEST_VERIFY_EXIT (fgetws (buf, sizeof (buf), stdout) != NULL);
+  TEST_VERIFY (wcscmp (buf, L"abcdef") == 0);
+
+  return 0;
+}
+
+static int
+do_test (void)
+{
+  return do_test_narrow () + do_test_wide ();
+}
+
+#include <support/test-driver.c>
diff --git a/libio/wfileops.c b/libio/wfileops.c
index 78f20486e5..0367643703 100644
--- a/libio/wfileops.c
+++ b/libio/wfileops.c
@@ -208,13 +208,13 @@  _IO_wfile_underflow (FILE *fp)
 	 traditional Unix systems did this for stdout.  stderr better
 	 not be line buffered.  So we do just that here
 	 explicitly.  --drepper */
-      _IO_acquire_lock (_IO_stdout);
+      _IO_acquire_lock (stdout);
 
-      if ((_IO_stdout->_flags & (_IO_LINKED | _IO_NO_WRITES | _IO_LINE_BUF))
+      if ((stdout->_flags & (_IO_LINKED | _IO_NO_WRITES | _IO_LINE_BUF))
 	  == (_IO_LINKED | _IO_LINE_BUF))
-	_IO_OVERFLOW (_IO_stdout, EOF);
+	_IO_OVERFLOW (stdout, EOF);
 
-      _IO_release_lock (_IO_stdout);
+      _IO_release_lock (stdout);
     }
 
   _IO_switch_to_get_mode (fp);