Jim Meyering wrote:
> I think I'll have to resort to using a moderately large width, yet
> with limited virtual memory, e.g., via ulimit -v 10000.
Here is the beginning of a proposal for m4/printf.m4 along these lines.
*** m4/printf.m4.orig 2007-11-03 05:38:54.000000000 +0100
--- m4/printf.m4 2007-11-03 03:01:53.000000000 +0100
***************
*** 1,4 ****
! # printf.m4 serial 17
dnl Copyright (C) 2003, 2007 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
--- 1,4 ----
! # printf.m4 serial 18
dnl Copyright (C) 2003, 2007 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
***************
*** 721,726 ****
--- 721,823 ----
])
])
+ dnl Test whether the *printf family of functions recovers gracefully in case
+ dnl of an out-of-memory condition, or whether it crashes the entire program.
+ dnl Result is gl_cv_func_printf_enomem.
+
+ AC_DEFUN([gl_PRINTF_ENOMEM]
+ [
+ AC_REQUIRE([AC_PROG_CC])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether printf survives out-of-memory conditions],
+ [gl_cv_func_printf_enomem],
+ [
+ if test "$cross_compiling" != no; then
+ AC_LANG_CONFTEST([AC_LANG_SOURCE([
+ changequote(,)dnl
+ #include <stdio.h>
+ #include <sys/types.h>
+ #include <sys/time.h>
+ #include <sys/resource.h>
+ #include <errno.h>
+ int main()
+ {
+ struct rlimit limit;
+ int ret;
+ /* Some printf implementations allocate temporary space with malloc. */
+ /* On BSD systems, malloc() is limited by RLIMIT_DATA. */
+ #ifdef RLIMIT_DATA
+ if (getrlimit (RLIMIT_DATA, &limit) < 0)
+ return 77;
+ if (limit.rlim_max == RLIM_INFINITY || limit.rlim_max > 1000000)
+ limit.rlim_max = 1000000;
+ limit.rlim_cur = limit.rlim_max;
+ if (setrlimit (RLIMIT_DATA, &limit) < 0)
+ return 77;
+ #endif
+ /* On Linux systems, malloc() is limited by RLIMIT_AS. */
+ #ifdef RLIMIT_AS
+ if (getrlimit (RLIMIT_AS, &limit) < 0)
+ return 77;
+ if (limit.rlim_max == RLIM_INFINITY || limit.rlim_max > 1000000)
+ limit.rlim_max = 1000000;
+ limit.rlim_cur = limit.rlim_max;
+ if (setrlimit (RLIMIT_AS, &limit) < 0)
+ return 77;
+ #endif
+ /* Some printf implementations allocate temporary space on the stack. */
+ #ifdef RLIMIT_STACK
+ if (getrlimit (RLIMIT_STACK, &limit) < 0)
+ return 77;
+ if (limit.rlim_max == RLIM_INFINITY || limit.rlim_max > 1000000)
+ limit.rlim_max = 1000000;
+ limit.rlim_cur = limit.rlim_max;
+ if (setrlimit (RLIMIT_STACK, &limit) < 0)
+ return 77;
+ #endif
+ ret = printf ("%.1000000f", 1.0);
+ return !(ret == 1000002 || (ret < 0 && errno == ENOMEM));
+ }
+ changequote([,])dnl
+ ])])
+ if AC_TRY_EVAL([ac_link]) && test -s conftest$ac_exeext; then
+ (./conftest) >/dev/null 2>/dev/null
+ case $? in
+ 0) gl_cv_func_printf_enomem="yes" ;;
+ 77) gl_cv_func_printf_enomem="guessing no" ;;
+ *) gl_cv_func_printf_enomem="no" ;;
+ esac
+ else
+ gl_cv_func_printf_enomem="guessing no" ;;
+ fi
+ rm -fr conftest*
+ else
+ changequote(,)dnl
+ case "$host_os" in
+ # Guess yes on glibc systems.
+ *-gnu*) gl_cv_func_printf_enomem="guessing yes";;
+ # Guess yes on AIX.
+ aix*) gl_cv_func_printf_enomem="guessing yes";;
+ # Guess yes on HP-UX/hppa.
+ hpux*) case "$host_cpu" in
+ hppa*) gl_cv_func_printf_enomem="guessing yes";;
+ *) gl_cv_func_printf_enomem="guessing no";;
+ esac
+ ;;
+ # Guess yes on IRIX.
+ irix*) gl_cv_func_printf_enomem="guessing yes";;
+ # Guess yes on OSF/1.
+ osf*) gl_cv_func_printf_enomem="guessing yes";;
+ # Guess yes on BeOS.
+ beos*) gl_cv_func_printf_enomem="guessing yes";;
+ # If we don't know, assume the worst.
+ *) gl_cv_func_printf_enomem="guessing no";;
+ esac
+ changequote([,])dnl
+ fi
+ ])
+ ])
+
dnl Test whether the snprintf function exists. (ISO C99, POSIX:2001)
dnl Result is ac_cv_func_snprintf.
***************
*** 1039,1049 ****
dnl 8 = gl_PRINTF_POSITIONS
dnl 9 = gl_PRINTF_FLAG_GROUPING
dnl 10 = gl_PRINTF_FLAG_ZERO
! dnl 11 = gl_SNPRINTF_PRESENCE
! dnl 12 = gl_SNPRINTF_TRUNCATION_C99
! dnl 13 = gl_SNPRINTF_RETVAL_C99
! dnl 14 = gl_SNPRINTF_DIRECTIVE_N
! dnl 15 = gl_VSNPRINTF_ZEROSIZE_C99
dnl
dnl 1 = checking whether printf supports size specifiers as in C99...
dnl 2 = checking whether printf supports 'long double' arguments...
--- 1136,1147 ----
dnl 8 = gl_PRINTF_POSITIONS
dnl 9 = gl_PRINTF_FLAG_GROUPING
dnl 10 = gl_PRINTF_FLAG_ZERO
! dnl 11 = gl_PRINTF_ENOMEM
! dnl 12 = gl_SNPRINTF_PRESENCE
! dnl 13 = gl_SNPRINTF_TRUNCATION_C99
! dnl 14 = gl_SNPRINTF_RETVAL_C99
! dnl 15 = gl_SNPRINTF_DIRECTIVE_N
! dnl 16 = gl_VSNPRINTF_ZEROSIZE_C99
dnl
dnl 1 = checking whether printf supports size specifiers as in C99...
dnl 2 = checking whether printf supports 'long double' arguments...
***************
*** 1055,1087 ****
dnl 8 = checking whether printf supports POSIX/XSI format strings with
positions...
dnl 9 = checking whether printf supports the grouping flag...
dnl 10 = checking whether printf supports the zero flag correctly...
! dnl 11 = checking for snprintf...
! dnl 12 = checking whether snprintf truncates the result as in C99...
! dnl 13 = checking whether snprintf returns a byte count as in C99...
! dnl 14 = checking whether snprintf fully supports the 'n' directive...
! dnl 15 = checking whether vsnprintf respects a zero size as in C99...
dnl
dnl . = yes, # = no.
dnl
! dnl 1 2 3 4 5 6 7 8 9 10 11 12 13 14
15
! dnl glibc 2.5 . . . . . . . . . . . . . .
.
! dnl glibc 2.3.6 . . . . # . . . . . . . . .
.
! dnl FreeBSD 5.4, 6.1 . . . . # . . . . # . . . .
.
! dnl MacOS X 10.3.9 . . . . # . . . . # . . . .
.
! dnl OpenBSD 3.9, 4.0 . ? ? ? # ? . . ? ? . . . ?
?
! dnl Cygwin 2007 (= Cygwin 1.5.24) . . . . # # . . . # . . . .
.
! dnl Cygwin 2006 (= Cygwin 1.5.19) # . . . # # . . # # . . . .
.
! dnl Solaris 10 . . # # # . . . . # . . . .
.
! dnl Solaris 2.6 ... 9 # . # # # # . . . # . . . .
.
! dnl Solaris 2.5.1 # . # # # # . . . # # # # #
#
! dnl AIX 5.2 . . # # # . . . . # . . . .
.
! dnl AIX 4.3.2, 5.1 # . # # # # . . . # . . . .
.
! dnl HP-UX 11.31 . . . . # . . . . # . . # #
.
! dnl HP-UX 10.20, 11.{00,11,23} # . . . # # . . . # . . # #
#
! dnl IRIX 6.5 # . # # # # . . . # . . # .
.
! dnl OSF/1 5.1 # . # # # # . . . # . . # .
#
! dnl OSF/1 4.0d # . # # # # . . . # # # # #
#
! dnl NetBSD 4.0 . ? ? ? ? ? . . ? ? . . . ?
?
! dnl NetBSD 3.0 . . . . # # . # # # . . . .
.
! dnl BeOS # # . # # # . # . . . . . .
.
! dnl mingw # # # # # # . # # # . # # #
.
--- 1153,1186 ----
dnl 8 = checking whether printf supports POSIX/XSI format strings with
positions...
dnl 9 = checking whether printf supports the grouping flag...
dnl 10 = checking whether printf supports the zero flag correctly...
! dnl 11 = checking whether printf survives out-of-memory conditions...
! dnl 12 = checking for snprintf...
! dnl 13 = checking whether snprintf truncates the result as in C99...
! dnl 14 = checking whether snprintf returns a byte count as in C99...
! dnl 15 = checking whether snprintf fully supports the 'n' directive...
! dnl 16 = checking whether vsnprintf respects a zero size as in C99...
dnl
dnl . = yes, # = no.
dnl
! dnl 1 2 3 4 5 6 7 8 9 10 11 12 13 14
15 16
! dnl glibc 2.5 . . . . . . . . . . . . . .
. .
! dnl glibc 2.3.6 . . . . # . . . . . . . . .
. .
! dnl FreeBSD 5.4, 6.1 . . . . # . . . . # # . . .
. .
! dnl MacOS X 10.3.9 . . . . # . . . . # # . . .
. .
! dnl OpenBSD 3.9, 4.0 . ? ? ? # ? . . ? ? ? . . .
? ?
! dnl Cygwin 2007 (= Cygwin 1.5.24) . . . . # # . . . # ? . . .
. .
! dnl Cygwin 2006 (= Cygwin 1.5.19) # . . . # # . . # # ? . . .
. .
! dnl Solaris 10 . . # # # . . . . # # . . .
. .
! dnl Solaris 2.6 ... 9 # . # # # # . . . # . . . .
. .
! dnl Solaris 2.5.1 # . # # # # . . . # . # # #
# #
! dnl AIX 5.2 . . # # # . . . . # . . . .
. .
! dnl AIX 4.3.2, 5.1 # . # # # # . . . # . . . .
. .
! dnl HP-UX 11.31 . . . . # . . . . # . . . #
# .
! dnl HP-UX 10.20, 11.{00,11,23} # . . . # # . . . # . . . #
# #
! dnl IRIX 6.5 # . # # # # . . . # . . . #
. .
! dnl OSF/1 5.1 # . # # # # . . . # . . . #
. #
! dnl OSF/1 4.0d # . # # # # . . . # . # # #
# #
! dnl NetBSD 4.0 . ? ? ? ? ? . . ? ? ? . . .
? ?
! dnl NetBSD 3.0 . . . . # # . # # # # . . .
. .
! dnl BeOS # # . # # # . # . . ? . . .
. .
! dnl mingw # # # # # # . # # # ? . # #
# .
