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Avoid some strlen work, primarily via strnlen

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* admin/merge-gnulib (GNULIB_MODULES): Add strnlen.
* lib-src/etags.c (find_entries):
* src/emacs.c (main):
* src/nsmenu.m (parseKeyEquiv:):
* src/nsterm.m (ns_xlfd_to_fontname):
* src/term.c (vfatal):
Prefer !*X to !strlen (X).
* lib-src/etags.c (pfnote, add_regex):
* lib-src/pop.c (pop_open):
* lib-src/update-game-score.c (main):
* lwlib/lwlib.c (lw_separator_p):
* src/doprnt.c (doprnt):
* src/emacs.c (main):
* src/inotify.c (inotifyevent_to_event):
* src/keyboard.c (menu_separator_name_p, parse_tool_bar_item):
* src/sysdep.c (get_current_dir_name_or_unreachable):
* src/xdisp.c (store_mode_line_string):
Use strnlen to avoid unnecessary work with strlen.
* lib-src/etags.c (Prolog_functions, prolog_pr)
(Erlang_functions, erlang_func):
Prefer ptrdiff_t to size_t when either will do.
(prolog_pr, erlang_func): New arg LASTLEN, to avoid
unnecessary strlen call. All callers changed.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lib/strnlen.c, m4/strnlen.m4: New files, copied from Gnulib.
* lwlib/lwlib.c (lw_separator_p):
* src/json.c (json_has_prefix):
Use strncmp to avoid unecessary work with strlen + memcmp.
* src/process.c (set_socket_option): Use SBYTES instead of strlen.
This commit is contained in:
Paul Eggert 2019-06-25 14:53:39 -07:00
parent 349b778dde
commit d7c6836288
20 changed files with 174 additions and 127 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
admin/merge-gnulib
View file

@ -40,7 +40,7 @@ GNULIB_MODULES='
manywarnings memmem-simple memrchr minmax mkostemp mktime nstrftime
pipe2 pselect pthread_sigmask putenv qcopy-acl readlink readlinkat regex
sig2str socklen stat-time std-gnu11 stdalign stddef stdio
stpcpy strtoimax symlink sys_stat sys_time
stpcpy strnlen strtoimax symlink sys_stat sys_time
tempname time time_r time_rz timegm timer-time timespec-add timespec-sub
update-copyright unlocked-io utimens
vla warnings

155
lib-src/etags.c
View file

@ -1811,7 +1811,7 @@ find_entries (FILE *inf)
}
*cp = '\0';
if (strlen (lp) > 0)
if (*lp)
{
lang = get_language_from_interpreter (lp);
if (lang != NULL && lang->function != NULL)
@ -2012,7 +2012,7 @@ pfnote (char *name, bool is_func, char *linestart, int linelen, int lno,
np->left = np->right = NULL;
if (CTAGS && !cxref_style)
{
if (strlen (linestart) < 50)
if (strnlen (linestart, 50) < 50)
np->regex = concat (linestart, "$", "");
else
np->regex = savenstr (linestart, 50);
@ -5883,20 +5883,15 @@ HTML_labels (FILE *inf)
* Original code by Sunichirou Sugou (1989)
* Rewritten by Anders Lindgren (1996)
*/
static size_t prolog_pr (char *, char *);
static ptrdiff_t prolog_pr (char *, char *, ptrdiff_t);
static void prolog_skip_comment (linebuffer *, FILE *);
static size_t prolog_atom (char *, size_t);
static void
Prolog_functions (FILE *inf)
{
char *cp, *last;
size_t len;
size_t allocated;
allocated = 0;
len = 0;
last = NULL;
char *cp, *last = NULL;
ptrdiff_t lastlen = 0, allocated = 0;
LOOP_ON_INPUT_LINES (inf, lb, cp)
{
@ -5906,17 +5901,22 @@ Prolog_functions (FILE *inf)
continue;
else if (cp[0] == '/' && cp[1] == '*') /* comment. */
prolog_skip_comment (&lb, inf);
else if ((len = prolog_pr (cp, last)) > 0)
else
{
/* Predicate or rule. Store the function name so that we
only generate a tag for the first clause. */
if (last == NULL)
last = xnew (len + 1, char);
else if (len + 1 > allocated)
xrnew (last, len + 1, char);
allocated = len + 1;
memcpy (last, cp, len);
last[len] = '\0';
ptrdiff_t len = prolog_pr (cp, last, lastlen);
if (0 < len)
{
/* Store the predicate name to avoid generating duplicate
tags later. */
if (allocated <= len)
{
xrnew (last, len + 1, char);
allocated = len + 1;
}
memcpy (last, cp, len);
last[len] = '\0';
lastlen = len;
}
}
}
free (last);
@ -5949,33 +5949,25 @@ prolog_skip_comment (linebuffer *plb, FILE *inf)
* Return the size of the name of the predicate or rule, or 0 if no
* header was found.
*/
static size_t
prolog_pr (char *s, char *last)
/* Name of last clause. */
static ptrdiff_t
prolog_pr (char *s, char *last, ptrdiff_t lastlen)
{
size_t pos;
size_t len;
pos = prolog_atom (s, 0);
if (! pos)
ptrdiff_t len = prolog_atom (s, 0);
if (len == 0)
return 0;
ptrdiff_t pos = skip_spaces (s + len) - s;
len = pos;
pos = skip_spaces (s + pos) - s;
/* Save only the first clause. */
if ((s[pos] == '.'
|| (s[pos] == '(' && (pos += 1))
|| (s[pos] == ':' && s[pos + 1] == '-' && (pos += 2)))
&& (last == NULL /* save only the first clause */
|| len != strlen (last)
|| !strneq (s, last, len)))
{
make_tag (s, len, true, s, pos, lineno, linecharno);
return len;
}
else
return 0;
&& ! (lastlen == len && memcmp (s, last, len) == 0))
{
make_tag (s, len, true, s, pos, lineno, linecharno);
return len;
}
return 0;
}
/*
@ -6043,21 +6035,15 @@ prolog_atom (char *s, size_t pos)
* Assumes that Erlang functions start at column 0.
* Original code by Anders Lindgren (1996)
*/
static int erlang_func (char *, char *, int *);
static int erlang_func (char *, char *, ptrdiff_t, ptrdiff_t *);
static void erlang_attribute (char *);
static int erlang_atom (char *);
static void
Erlang_functions (FILE *inf)
{
char *cp, *last;
int len;
int allocated;
int name_offset = 0;
allocated = 0;
len = 0;
last = NULL;
char *cp, *last = NULL;
ptrdiff_t lastlen = 0, allocated = 0;
LOOP_ON_INPUT_LINES (inf, lb, cp)
{
@ -6078,19 +6064,23 @@ Erlang_functions (FILE *inf)
last = NULL;
}
}
else if ((len = erlang_func (cp, last, &name_offset)) > 0)
else
{
/*
* Function. Store the function name so that we only
* generates a tag for the first clause.
*/
if (last == NULL)
last = xnew (len + 1, char);
else if (len + 1 > allocated)
xrnew (last, len + 1, char);
allocated = len + 1;
memcpy (last, cp + name_offset, len);
last[len] = '\0';
ptrdiff_t name_offset;
ptrdiff_t len = erlang_func (cp, last, lastlen, &name_offset);
if (0 < len)
{
/* Store the function name to avoid generating duplicate
tags later. */
if (allocated <= len)
{
xrnew (last, len + 1, char);
allocated = len + 1;
}
memcpy (last, cp + name_offset, len);
last[len] = '\0';
lastlen = len;
}
}
}
free (last);
@ -6108,40 +6098,27 @@ Erlang_functions (FILE *inf)
* was found.
*/
static int
erlang_func (char *s, char *last, int *name_offset)
/* Name of last clause. */
erlang_func (char *s, char *last, ptrdiff_t lastlen, ptrdiff_t *name_offset)
{
int pos;
int len;
char *name = s;
pos = erlang_atom (s);
if (pos < 1)
ptrdiff_t len = erlang_atom (s);
if (len == 0)
return 0;
len = pos;
pos = skip_spaces (s + pos) - s;
ptrdiff_t pos = skip_spaces (s + len) - s;
/* If the name is quoted, the quotes are not part of the name. */
if (len > 2 && name[0] == '\'' && name[len - 1] == '\'')
{
*name_offset = 1;
name++;
len -= 2;
}
else
*name_offset = 0;
bool quoted = 2 < len && name[0] == '\'' && name[len - 1] == '\'';
name += quoted;
len -= 2 * quoted;
/* Save only the first clause. */
if (s[pos++] == '('
&& (last == NULL
|| len != (int)strlen (last)
|| !strneq (name, last, len)))
{
make_tag (name, len, true, s, pos, lineno, linecharno);
return len;
}
&& ! (lastlen == len && memcmp (name, last, len) == 0))
{
make_tag (s, len, true, s, pos, lineno, linecharno);
*name_offset = quoted;
return len;
}
return 0;
}
@ -6363,7 +6340,7 @@ add_regex (char *regexp_pattern, language *lang)
single_line = false; /* dot does not match newline */
if (strlen (regexp_pattern) < 3)
if (strnlen (regexp_pattern, 3) < 3)
{
error ("null regexp");
return;

4
lib-src/pop.c
View file

@ -285,7 +285,7 @@ pop_open (char *host, char *username, char *password, int flags)
/*
* I really shouldn't use the pop_error variable like this, but....
*/
if (strlen (username) > ERROR_MAX - 6)
if (strnlen (username, ERROR_MAX - 6 + 1) == ERROR_MAX - 6 + 1)
{
pop_close (server);
strcpy (pop_error,
@ -299,7 +299,7 @@ pop_open (char *host, char *username, char *password, int flags)
return (0);
}
if (strlen (password) > ERROR_MAX - 6)
if (strnlen (password, ERROR_MAX - 6 + 1) == ERROR_MAX - 6 + 1)
{
pop_close (server);
strcpy (pop_error,

2
lib-src/update-game-score.c
View file

@ -240,7 +240,7 @@ main (int argc, char **argv)
if (! user)
lose_syserr ("Couldn't determine user id");
data = argv[optind + 2];
if (strlen (data) > MAX_DATA_LEN)
if (strnlen (data, MAX_DATA_LEN + 1) == MAX_DATA_LEN + 1)
data[MAX_DATA_LEN] = '\0';
nl = strchr (data, '\n');
if (nl)

14
lib/gnulib.mk.in
View file

@ -136,6 +136,7 @@
# stddef \
# stdio \
# stpcpy \
# strnlen \
# strtoimax \
# symlink \
# sys_stat \
@ -1075,7 +1076,6 @@ gl_GNULIB_ENABLED_getdtablesize = @gl_GNULIB_ENABLED_getdtablesize@
gl_GNULIB_ENABLED_getgroups = @gl_GNULIB_ENABLED_getgroups@
gl_GNULIB_ENABLED_malloca = @gl_GNULIB_ENABLED_malloca@
gl_GNULIB_ENABLED_open = @gl_GNULIB_ENABLED_open@
gl_GNULIB_ENABLED_pathmax = @gl_GNULIB_ENABLED_pathmax@
gl_GNULIB_ENABLED_strtoll = @gl_GNULIB_ENABLED_strtoll@
gl_LIBOBJS = @gl_LIBOBJS@
gl_LTLIBOBJS = @gl_LTLIBOBJS@
@ -1110,7 +1110,6 @@ pdfdir = @pdfdir@
prefix = @prefix@
program_transform_name = @program_transform_name@
psdir = @psdir@
runstatedir = @runstatedir@
sbindir = @sbindir@
sharedstatedir = @sharedstatedir@
srcdir = @srcdir@
@ -2811,6 +2810,17 @@ EXTRA_DIST += string.in.h
endif
## end gnulib module string
## begin gnulib module strnlen
ifeq (,$(OMIT_GNULIB_MODULE_strnlen))
EXTRA_DIST += strnlen.c
EXTRA_libgnu_a_SOURCES += strnlen.c
endif
## end gnulib module strnlen
## begin gnulib module strtoimax
ifeq (,$(OMIT_GNULIB_MODULE_strtoimax))

30
lib/strnlen.c Normal file
View file

@ -0,0 +1,30 @@
/* Find the length of STRING, but scan at most MAXLEN characters.
Copyright (C) 2005-2007, 2009-2019 Free Software Foundation, Inc.
Written by Simon Josefsson.
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, 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 <https://www.gnu.org/licenses/>. */
#include <config.h>
#include <string.h>
/* Find the length of STRING, but scan at most MAXLEN characters.
If no '\0' terminator is found in that many characters, return MAXLEN. */
size_t
strnlen (const char *string, size_t maxlen)
{
const char *end = memchr (string, '\0', maxlen);
return end ? (size_t) (end - string) : maxlen;
}

5
lwlib/lwlib.c
View file

@ -1233,8 +1233,7 @@ lw_separator_p (const char *label, enum menu_separator *type, int motif_p)
{
int separator_p = 0;
if (strlen (label) >= 3
&& memcmp (label, "--:", 3) == 0)
if (strncmp (label, "--:", 3) == 0)
{
static struct separator_table
{
@ -1276,7 +1275,7 @@ lw_separator_p (const char *label, enum menu_separator *type, int motif_p)
break;
}
}
else if (strlen (label) > 3
else if (strnlen (label, 4) == 4
&& memcmp (label, "--", 2) == 0
&& label[2] != '-')
{

9
m4/gnulib-comp.m4
View file

@ -154,6 +154,7 @@ AC_DEFUN([gl_EARLY],
# Code from module stdlib:
# Code from module stpcpy:
# Code from module string:
# Code from module strnlen:
# Code from module strtoimax:
# Code from module strtoll:
# Code from module symlink:
@ -403,6 +404,12 @@ AC_DEFUN([gl_INIT],
fi
gl_STRING_MODULE_INDICATOR([stpcpy])
gl_HEADER_STRING_H
gl_FUNC_STRNLEN
if test $HAVE_DECL_STRNLEN = 0 || test $REPLACE_STRNLEN = 1; then
AC_LIBOBJ([strnlen])
gl_PREREQ_STRNLEN
fi
gl_STRING_MODULE_INDICATOR([strnlen])
gl_FUNC_STRTOIMAX
if test $HAVE_DECL_STRTOIMAX = 0 || test $REPLACE_STRTOIMAX = 1; then
AC_LIBOBJ([strtoimax])
@ -1003,6 +1010,7 @@ AC_DEFUN([gl_FILE_LIST], [
lib/str-two-way.h
lib/strftime.h
lib/string.in.h
lib/strnlen.c
lib/strtoimax.c
lib/strtol.c
lib/strtoll.c
@ -1131,6 +1139,7 @@ AC_DEFUN([gl_FILE_LIST], [
m4/stdlib_h.m4
m4/stpcpy.m4
m4/string_h.m4
m4/strnlen.m4
m4/strtoimax.m4
m4/strtoll.m4
m4/symlink.m4

30
m4/strnlen.m4 Normal file
View file

@ -0,0 +1,30 @@
# strnlen.m4 serial 13
dnl Copyright (C) 2002-2003, 2005-2007, 2009-2019 Free Software Foundation,
dnl Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
AC_DEFUN([gl_FUNC_STRNLEN],
[
AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
dnl Persuade glibc <string.h> to declare strnlen().
AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
AC_CHECK_DECLS_ONCE([strnlen])
if test $ac_cv_have_decl_strnlen = no; then
HAVE_DECL_STRNLEN=0
else
m4_pushdef([AC_LIBOBJ], [:])
dnl Note: AC_FUNC_STRNLEN does AC_LIBOBJ([strnlen]).
AC_FUNC_STRNLEN
m4_popdef([AC_LIBOBJ])
if test $ac_cv_func_strnlen_working = no; then
REPLACE_STRNLEN=1
fi
fi
])
# Prerequisites of lib/strnlen.c.
AC_DEFUN([gl_PREREQ_STRNLEN], [:])

4
src/doprnt.c
View file

@ -357,8 +357,8 @@ doprnt (char *buffer, ptrdiff_t bufsize, const char *format,
if (fmtcpy[1] != 's')
minlen = atoi (&fmtcpy[1]);
string = va_arg (ap, char *);
tem = strlen (string);
if (STRING_BYTES_BOUND < tem)
tem = strnlen (string, STRING_BYTES_BOUND + 1);
if (tem == STRING_BYTES_BOUND + 1)
error ("String for %%s or %%S format is too long");
width = strwidth (string, tem);
goto doit1;

4
src/emacs.c
View file

@ -1520,8 +1520,8 @@ Using an Emacs configured with --with-x-toolkit=lucid does not have this problem
}
/* In exec'd: parse special dname into pipe and name info. */
if (!dname_arg || !strchr (dname_arg, '\n')
|| strlen (dname_arg) < 1 || strlen (dname_arg) > 70)
if (!dname_arg || !*dname_arg || strnlen (dname_arg, 71) == 71
|| !strchr (dname_arg, '\n'))
{
fprintf (stderr, "emacs daemon: daemon name absent or too long\n");
exit (EXIT_CANNOT_INVOKE);

3
src/inotify.c
View file

@ -181,8 +181,7 @@ inotifyevent_to_event (Lisp_Object watch, struct inotify_event const *ev)
if (ev->len > 0)
{
size_t const len = strlen (ev->name);
name = make_unibyte_string (ev->name, min (len, ev->len));
name = make_unibyte_string (ev->name, strnlen (ev->name, ev->len));
name = DECODE_FILE (name);
}
else

4
src/json.c
View file

@ -197,9 +197,7 @@ init_json (void)
static bool
json_has_prefix (const char *string, const char *prefix)
{
size_t string_len = strlen (string);
size_t prefix_len = strlen (prefix);
return string_len >= prefix_len && memcmp (string, prefix, prefix_len) == 0;
return strncmp (string, prefix, strlen (prefix)) == 0;
}
/* Return whether STRING ends with SUFFIX. */

15
src/keyboard.c
View file

@ -7331,7 +7331,7 @@ menu_separator_name_p (const char *label)
{
if (!label)
return 0;
else if (strlen (label) > 3
else if (strnlen (label, 4) == 4
&& memcmp (label, "--", 2) == 0
&& label[2] != '-')
{
@ -8248,13 +8248,13 @@ parse_tool_bar_item (Lisp_Object key, Lisp_Object item)
Lisp_Object tcapt = PROP (TOOL_BAR_ITEM_CAPTION);
const char *label = SYMBOLP (tkey) ? SSDATA (SYMBOL_NAME (tkey)) : "";
const char *capt = STRINGP (tcapt) ? SSDATA (tcapt) : "";
ptrdiff_t max_lbl =
2 * max (0, min (tool_bar_max_label_size, STRING_BYTES_BOUND / 2));
char *buf = xmalloc (max_lbl + 1);
ptrdiff_t max_lbl_size =
2 * max (0, min (tool_bar_max_label_size, STRING_BYTES_BOUND / 2)) + 1;
char *buf = xmalloc (max_lbl_size);
Lisp_Object new_lbl;
ptrdiff_t caption_len = strlen (capt);
ptrdiff_t caption_len = strnlen (capt, max_lbl_size);
if (caption_len <= max_lbl && capt[0] != '\0')
if (0 < caption_len && caption_len < max_lbl_size)
{
strcpy (buf, capt);
while (caption_len > 0 && buf[caption_len - 1] == '.')
@ -8263,7 +8263,8 @@ parse_tool_bar_item (Lisp_Object key, Lisp_Object item)
label = capt = buf;
}
if (strlen (label) <= max_lbl && label[0] != '\0')
ptrdiff_t label_len = strnlen (label, max_lbl_size);
if (0 < label_len && label_len < max_lbl_size)
{
ptrdiff_t j;
if (label != buf)

2
src/nsmenu.m
View file

@ -611,7 +611,7 @@ -(NSString *)parseKeyEquiv: (const char *)key
const char *tpos = key;
keyEquivModMask = NSEventModifierFlagCommand;
if (!key || !strlen (key))
if (!key || !*key)
return @"";
while (*tpos == ' ' || *tpos == '(')

2
src/nsterm.m
View file

@ -9298,7 +9298,7 @@ Convert an X font name (XLFD) to an NS font name.
sscanf (xlfd, "-%*[^-]-%179[^-]-", name);
/* stopgap for malformed XLFD input */
if (strlen (name) == 0)
if (!*name)
strcpy (name, "Monaco");
/* undo hack in ns_fontname_to_xlfd, converting '$' to '-', '_' to ' '

6
src/process.c
View file

@ -2857,11 +2857,7 @@ set_socket_option (int s, Lisp_Object opt, Lisp_Object val)
This should work on all systems. KFS. 2003-09-23. */
memset (devname, 0, sizeof devname);
if (STRINGP (val))
{
char *arg = SSDATA (val);
int len = min (strlen (arg), IFNAMSIZ);
memcpy (devname, arg, len);
}
memcpy (devname, SDATA (val), min (SBYTES (val), IFNAMSIZ));
else if (!NILP (val))
error ("Bad option value for %s", name);
ret = setsockopt (s, sopt->optlevel, sopt->optnum,

4
src/sysdep.c
View file

@ -281,7 +281,7 @@ get_current_dir_name_or_unreachable (void)
pwd = get_current_dir_name ();
if (pwd)
{
if (strlen (pwd) < dirsize_max)
if (strnlen (pwd, dirsize_max) < dirsize_max)
return pwd;
free (pwd);
errno = ERANGE;
@ -298,7 +298,7 @@ get_current_dir_name_or_unreachable (void)
sometimes a nicer name, and using it may avoid a fatal error if a
parent directory is searchable but not readable. */
if (pwd
&& (pwdlen = strlen (pwd)) < bufsize_max
&& (pwdlen = strnlen (pwd, bufsize_max)) < bufsize_max
&& IS_DIRECTORY_SEP (pwd[pwdlen && IS_DEVICE_SEP (pwd[1]) ? 2 : 0])
&& stat (pwd, &pwdstat) == 0
&& stat (".", &dotstat) == 0

2
src/term.c
View file

@ -4400,7 +4400,7 @@ vfatal (const char *str, va_list ap)
{
fprintf (stderr, "emacs: ");
vfprintf (stderr, str, ap);
if (!(strlen (str) > 0 && str[strlen (str) - 1] == '\n'))
if (! (str[0] && str[strlen (str) - 1] == '\n'))
fprintf (stderr, "\n");
exit (1);
}

4
src/xdisp.c
View file

@ -24341,9 +24341,7 @@ store_mode_line_string (const char *string, Lisp_Object lisp_string,
if (string != NULL)
{
len = strlen (string);
if (precision > 0 && len > precision)
len = precision;
len = strnlen (string, precision <= 0 ? SIZE_MAX : precision);
lisp_string = make_string (string, len);
if (NILP (props))
props = mode_line_string_face_prop;