Package: emacs;
Reported by: Paul Eggert <eggert <at> cs.ucla.edu>
Date: Sat, 12 Jan 2013 06:51:01 UTC
Severity: minor
Tags: patch
Done: Paul Eggert <eggert <at> cs.ucla.edu>
Bug is archived. No further changes may be made.
Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):
From: Paul Eggert <eggert <at> cs.ucla.edu> To: bug-gnu-emacs <at> gnu.org Subject: make 'eabs' act more like a function Date: Fri, 11 Jan 2013 22:44:19 -0800
Tags: patch
Severity: minor
This patch doesn't fix any bugs, it's just a code cleanup.
It fixes 'eabs (X)' so that it evaluates X just once
instead of twice. As Emacs is currently written this shouldn't
affect efficiency or behavior, but it is a nicety.
The key part of this patch is to lisp.h; most of the rest
is pulled in from gnulib automatically. I'm guessing about
the change to nt/inc/inttypes.h, as I don't use Windows.
=== modified file 'ChangeLog'
--- ChangeLog 2013-01-12 05:21:06 +0000
+++ ChangeLog 2013-01-12 06:31:32 +0000
@@ -1,5 +1,10 @@
2013-01-12 Paul Eggert <eggert <at> cs.ucla.edu>
+ Make eabs act more like a function.
+ * configure.ac: Invoke AC_C_TYPEOF.
+ * lib/imaxabs.c, m4/imaxabs.m4, m4/_Generic.m4: New files, from gnulib.
+ * lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
+
Enable conservative stack scanning for all architectures.
Suggested by Stefan Monnier in
<http://lists.gnu.org/archive/html/emacs-devel/2013-01/msg00183.html>.
=== modified file 'admin/ChangeLog'
--- admin/ChangeLog 2013-01-10 03:43:02 +0000
+++ admin/ChangeLog 2013-01-12 01:03:44 +0000
@@ -1,3 +1,8 @@
+2013-01-12 Paul Eggert <eggert <at> cs.ucla.edu>
+
+ Make eabs act more like a function.
+ * merge-gnulib (GNULIB_MODULES): Add _Generic, imaxabs.
+
2013-01-03 Glenn Morris <rgm <at> gnu.org>
* check-doc-strings: Update for CVS->bzr, moved lispref/ directory.
=== modified file 'admin/merge-gnulib'
--- admin/merge-gnulib 2013-01-02 16:13:04 +0000
+++ admin/merge-gnulib 2013-01-12 01:03:44 +0000
@@ -26,11 +26,11 @@
GNULIB_URL=git://git.savannah.gnu.org/gnulib.git
GNULIB_MODULES='
- alloca-opt c-ctype c-strcase
+ _Generic alloca-opt c-ctype c-strcase
careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512
dtoastr dtotimespec dup2 environ execinfo faccessat
fcntl-h filemode getloadavg getopt-gnu gettime gettimeofday
- ignore-value intprops largefile lstat
+ ignore-value imaxabs intprops largefile lstat
manywarnings mktime pselect pthread_sigmask putenv readlink
sig2str socklen stat-time stdalign stdarg stdbool stdio
strftime strtoimax strtoumax symlink sys_stat
=== modified file 'configure.ac'
--- configure.ac 2013-01-12 05:21:06 +0000
+++ configure.ac 2013-01-12 06:31:32 +0000
@@ -3350,6 +3350,8 @@
AC_TYPE_MBSTATE_T
+AC_C_TYPEOF
+
AC_CACHE_CHECK([for C restricted array declarations], emacs_cv_c_restrict_arr,
[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[void fred (int x[__restrict]);]], [[]])],
emacs_cv_c_restrict_arr=yes, emacs_cv_c_restrict_arr=no)])
=== modified file 'lib/gnulib.mk'
--- lib/gnulib.mk 2013-01-04 02:17:49 +0000
+++ lib/gnulib.mk 2013-01-12 01:03:44 +0000
@@ -21,7 +21,7 @@
# the same distribution terms as the rest of that program.
#
# Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=at-internal --avoid=errno --avoid=fchdir --avoid=fcntl --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=openat-die --avoid=openat-h --avoid=raise --avoid=save-cwd --avoid=select --avoid=sigprocmask --avoid=sys_types --avoid=threadlib --makefile-name=gnulib.mk --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt c-ctype c-strcase careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo faccessat fcntl-h filemode getloadavg getopt-gnu gettime gettimeofday ignore-value intprops largefile lstat manywarnings mktime pselect pthread_sigmask putenv readlink sig2str socklen stat-time stdalign stdarg stdbool stdio strftime strtoimax strtoumax symlink sys_stat sys_time time timer-time timespec-add timespec-sub uns
etenv uti
mens warnings
+# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=at-internal --avoid=errno --avoid=fchdir --avoid=fcntl --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=openat-die --avoid=openat-h --avoid=raise --avoid=save-cwd --avoid=select --avoid=sigprocmask --avoid=sys_types --avoid=threadlib --makefile-name=gnulib.mk --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files _Generic alloca-opt c-ctype c-strcase careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo faccessat fcntl-h filemode getloadavg getopt-gnu gettime gettimeofday ignore-value imaxabs intprops largefile lstat manywarnings mktime pselect pthread_sigmask putenv readlink sig2str socklen stat-time stdalign stdarg stdbool stdio strftime strtoimax strtoumax symlink sys_stat sys_time time timer-time timespec-add
timespec
-sub unsetenv utimens warnings
MOSTLYCLEANFILES += core *.stackdump
@@ -343,6 +343,15 @@
## end gnulib module ignore-value
+## begin gnulib module imaxabs
+
+
+EXTRA_DIST += imaxabs.c
+
+EXTRA_libgnu_a_SOURCES += imaxabs.c
+
+## end gnulib module imaxabs
+
## begin gnulib module intprops
=== added file 'lib/imaxabs.c'
--- lib/imaxabs.c 1970-01-01 00:00:00 +0000
+++ lib/imaxabs.c 2013-01-10 08:23:32 +0000
@@ -0,0 +1,26 @@
+/* imaxabs() function: absolute value of 'intmax_t'.
+ Copyright (C) 2006, 2009-2013 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/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include <inttypes.h>
+
+intmax_t
+imaxabs (intmax_t x)
+{
+ return (x >= 0 ? x : - x);
+}
=== added file 'm4/_Generic.m4'
--- m4/_Generic.m4 1970-01-01 00:00:00 +0000
+++ m4/_Generic.m4 2013-01-12 01:03:44 +0000
@@ -0,0 +1,34 @@
+# Test for C11-style _Generic
+dnl Copyright 2012-2013 Free Software Foundation, 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.
+
+dnl Written by Paul Eggert.
+
+# Backport of autoconf-2.70's macro.
+# Remove this macro when we can assume autoconf >= 2.70.
+m4_ifndef([AC_C__GENERIC],
+[AC_DEFUN([AC_C__GENERIC],
+[AC_CACHE_CHECK([for _Generic], ac_cv_c__Generic,
+[AC_COMPILE_IFELSE(
+ [AC_LANG_SOURCE(
+ [[int
+ main (int argc, char **argv)
+ {
+ int a = _Generic (argc, int: argc = 1);
+ int *b = &_Generic (argc, default: argc);
+ char ***c = _Generic (argv, int: argc, default: argv ? &argv : 0);
+ _Generic (1 ? 0 : b, int: a, default: b) = &argc;
+ _Generic (a = 1, default: a) = 3;
+ return a + !b + !c;
+ }
+ ]])],
+ [ac_cv_c__Generic=yes],
+ [ac_cv_c__Generic=no])])
+if test $ac_cv_c__Generic = yes; then
+ AC_DEFINE([HAVE_C__GENERIC], 1,
+ [Define to 1 if C11-style _Generic works.])
+fi
+])
+])
=== modified file 'm4/gnulib-comp.m4'
--- m4/gnulib-comp.m4 2013-01-04 02:17:49 +0000
+++ m4/gnulib-comp.m4 2013-01-12 01:03:44 +0000
@@ -38,6 +38,7 @@
m4_pattern_allow([^gl_LIBOBJS$])dnl a variable
m4_pattern_allow([^gl_LTLIBOBJS$])dnl a variable
AC_REQUIRE([gl_PROG_AR_RANLIB])
+ # Code from module _Generic:
# Code from module alloca-opt:
# Code from module allocator:
# Code from module c-ctype:
@@ -72,6 +73,7 @@
# Code from module gettimeofday:
# Code from module group-member:
# Code from module ignore-value:
+ # Code from module imaxabs:
# Code from module include_next:
# Code from module intprops:
# Code from module inttypes-incomplete:
@@ -150,6 +152,7 @@
m4_pushdef([gl_LIBSOURCES_DIR], [])
gl_COMMON
gl_source_base='lib'
+ AC_C__GENERIC
gl_FUNC_ALLOCA
AC_CHECK_FUNCS_ONCE([readlinkat])
gl_CLOCK_TIME
@@ -216,6 +219,12 @@
gl_PREREQ_GETTIMEOFDAY
fi
gl_SYS_TIME_MODULE_INDICATOR([gettimeofday])
+ gl_FUNC_IMAXABS
+ if test $ac_cv_func_imaxabs = no; then
+ AC_LIBOBJ([imaxabs])
+ gl_PREREQ_IMAXABS
+ fi
+ gl_INTTYPES_MODULE_INDICATOR([imaxabs])
gl_INTTYPES_INCOMPLETE
AC_REQUIRE([gl_LARGEFILE])
gl_FUNC_LSTAT
@@ -682,6 +691,7 @@
lib/gettimeofday.c
lib/group-member.c
lib/ignore-value.h
+ lib/imaxabs.c
lib/intprops.h
lib/inttypes.in.h
lib/lstat.c
@@ -742,6 +752,7 @@
lib/verify.h
lib/xalloc-oversized.h
m4/00gnulib.m4
+ m4/_Generic.m4
m4/alloca.m4
m4/c-strtod.m4
m4/clock_time.m4
@@ -764,6 +775,7 @@
m4/gettimeofday.m4
m4/gnulib-common.m4
m4/group-member.m4
+ m4/imaxabs.m4
m4/include_next.m4
m4/inttypes.m4
m4/largefile.m4
=== added file 'm4/imaxabs.m4'
--- m4/imaxabs.m4 1970-01-01 00:00:00 +0000
+++ m4/imaxabs.m4 2013-01-10 08:23:32 +0000
@@ -0,0 +1,20 @@
+# imaxabs.m4 serial 4
+dnl Copyright (C) 2006, 2009-2013 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_IMAXABS],
+[
+ AC_REQUIRE([gl_INTTYPES_H_DEFAULTS])
+
+ dnl On OSF/1 5.1 with cc, this function is declared but not defined.
+ AC_CHECK_FUNCS_ONCE([imaxabs])
+ AC_CHECK_DECLS_ONCE([imaxabs])
+ if test "$ac_cv_have_decl_imaxabs" != yes; then
+ HAVE_DECL_IMAXABS=0
+ fi
+])
+
+# Prerequisites of lib/imaxabs.c.
+AC_DEFUN([gl_PREREQ_IMAXABS], [:])
=== modified file 'nt/ChangeLog'
--- nt/ChangeLog 2013-01-11 09:33:54 +0000
+++ nt/ChangeLog 2013-01-12 01:04:47 +0000
@@ -1,3 +1,8 @@
+2013-01-12 Paul Eggert <eggert <at> cs.ucla.edu>
+
+ Make eabs act more like a function.
+ * inc/inttypes.h (imaxabs) [!__MINGW32__]: New macro.
+
2013-01-11 Eli Zaretskii <eliz <at> gnu.org>
* inc/unistd.h (O_IGNORE_CTTY): Define, as it is unconditionally
=== modified file 'nt/inc/inttypes.h'
--- nt/inc/inttypes.h 2013-01-01 09:11:05 +0000
+++ nt/inc/inttypes.h 2013-01-11 23:37:49 +0000
@@ -25,9 +25,11 @@
#else /* !__MINGW32__ */
#include "stdint.h"
#ifdef _WIN64
+#define imaxabs _abs64
#define strtoumax _strtoui64
#define strtoimax _strtoi64
#else
+#define imaxabs labs
#define strtoumax strtoul
#define strtoimax strtol
#endif
=== modified file 'src/ChangeLog'
--- src/ChangeLog 2013-01-12 06:15:12 +0000
+++ src/ChangeLog 2013-01-12 06:31:32 +0000
@@ -1,3 +1,8 @@
+2013-01-12 Paul Eggert <eggert <at> cs.ucla.edu>
+
+ Make eabs act more like a function.
+ * lisp.h (eabs): Evaluate arg just once.
+
2013-01-12 Dmitry Antipov <dmantipov <at> yandex.ru>
* indent.c (Fvertical_motion): Remove now-incorrect GCPROs
=== modified file 'src/lisp.h'
--- src/lisp.h 2013-01-12 05:21:06 +0000
+++ src/lisp.h 2013-01-12 06:31:32 +0000
@@ -3626,11 +3626,21 @@
/* Set up the name of the machine we're running on. */
extern void init_system_name (void);
-/* We used to use `abs', but that clashes with system headers on some
- platforms, and using a name reserved by Standard C is a bad idea
- anyway. */
-#if !defined (eabs)
-#define eabs(x) ((x) < 0 ? -(x) : (x))
+/* Return the absolute value of X, without evaluating X more than once.
+ X should be a signed integer, and X's absolute value should not
+ exceed the maximum for its promoted type.
+
+ If _Generic or typeof works, speed things up a bit by avoiding the
+ conversion to intmax_t. The "~" promotes X's type, and checks that
+ X is an integer. */
+#if HAVE_C__GENERIC
+# define eabs(x) \
+ (_Generic (~ (x), int: abs, long: labs, long long: llabs, default: imaxabs) \
+ (x))
+#elif HAVE_TYPEOF
+# define eabs(x) ({ typeof (~ (x)) eabsx = x; eabsx < 0 ? -eabsx : eabsx; })
+#else
+# define eabs(x) imaxabs (x)
#endif
/* Return a fixnum or float, depending on whether VAL fits in a Lisp
GNU bug tracking system
Copyright (C) 1999 Darren O. Benham,
1997,2003 nCipher Corporation Ltd,
1994-97 Ian Jackson.