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synced 2025-05-14 01:30:19 +02:00
5e9dc714ca
As the Autoconf documentation says, "These days portable programs [...] should not rely on `HAVE_RESTARTABLE_SYSCALLS', since nowadays whether a system call is restartable is a dynamic issue, not a configuration-time issue." In other words, if we ever rely on HAVE_RESTARTABLE_SYSCALLS, we are at the mercy of any code that Guile happens to be linked with, because that code could install a signal handler without the SA_RESTART flag, and then a Guile system call could unexpectedly return EINTR. The readline part of this goes back to this problem report: excellent example of the above paragraph. It was noted during the discussion that undefining HAVE_RESTARTABLE_SYSCALLS would fix the problem, but that solution wasn't adopted - I guess because Guile was still using cooperative threads then (not pthreads) and so there was a significant concern (whether founded or not) that not using restartable syscalls (where available) could lead to a loss of performance. Now Guile's default mode of operation is with pthreads, where we already don't assume that HAVE_RESTARTABLE_SYSCALLS is reliable, so there is no possible further performance loss. And in any case we really have no choice, if we want correct operation. * configure.in (AC_SYS_RESTARTABLE_SYSCALLS): Removed. * doc/ref/posix.texi (Signals): Remove statement that Guile always sets SA_RESTART flag. * guile-readline/configure.in (GUILE_SIGWINCH_SA_RESTART_CLEARED): Remove this setting, together with its test code. (HAVE_RL_PRE_INPUT_HOOK): Remove this setting and its code, as no longer needed. * guile-readline/readline.c (sigwinch_enable_restart): Removed. (scm_init_readline): Remove setting of rl_pre_input_hook. * libguile/_scm.h (SCM_SYSCALL): Remove the definition that relies on HAVE_RESTARTABLE_SYSCALLS. * libguile/scmsigs.c (scm_sigaction_for_thread): Don't always set the SA_RESTART flag if available. Update docstring accordingly. (scm_init_scmsigs): Remove code that sets SA_RESTART flag for all signals.
87 lines
2.4 KiB
Text
87 lines
2.4 KiB
Text
AC_PREREQ(2.50)
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dnl Don't use "echo -n", which is not portable (e.g., not available on
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dnl MacOS X). Instead, use `patsubst' to remove the newline.
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AC_INIT(guile-readline,
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patsubst(m4_esyscmd(. ../GUILE-VERSION && echo ${GUILE_VERSION}), [
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]),
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[bug-guile@gnu.org])
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AC_CONFIG_AUX_DIR([.])
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AC_CONFIG_SRCDIR(readline.c)
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AM_CONFIG_HEADER([guile-readline-config.h])
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AM_INIT_AUTOMAKE([foreign no-define])
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. $srcdir/../GUILE-VERSION
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AC_PROG_INSTALL
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AC_PROG_CC
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AM_PROG_CC_STDC
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AC_LIBTOOL_WIN32_DLL
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AC_PROG_LIBTOOL
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dnl
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dnl Check for Winsock and other functionality on Win32 (*not* CygWin)
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dnl
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AC_CYGWIN
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AC_MINGW32
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EXTRA_DEFS=""
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if test "$MINGW32" = "yes" ; then
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if test $enable_shared = yes ; then
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EXTRA_DEFS="-DSCM_IMPORT"
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fi
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fi
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AC_SUBST(EXTRA_DEFS)
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for termlib in ncurses curses termcap terminfo termlib ; do
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AC_CHECK_LIB(${termlib}, tgoto,
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[LIBS="-l${termlib} $LIBS"; break])
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done
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AC_CHECK_LIB(readline, readline)
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if test $ac_cv_lib_readline_readline = no; then
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AC_MSG_WARN([libreadline was not found on your system.])
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fi
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AC_CHECK_FUNCS(siginterrupt rl_clear_signals rl_cleanup_after_signal)
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dnl Check for modern readline naming
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AC_CHECK_FUNCS(rl_filename_completion_function)
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dnl Check for rl_get_keymap. We only use this for deciding whether to
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dnl install paren matching on the Guile command line (when using
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dnl readline for input), so it's completely optional.
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AC_CHECK_FUNCS(rl_get_keymap)
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AC_CACHE_CHECK([for rl_getc_function pointer in readline],
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ac_cv_var_rl_getc_function,
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[AC_TRY_LINK([
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#include <stdio.h>
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#include <readline/readline.h>],
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[printf ("%ld", (long) rl_getc_function)],
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[ac_cv_var_rl_getc_function=yes],
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[ac_cv_var_rl_getc_function=no])])
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if test "${ac_cv_var_rl_getc_function}" = "yes"; then
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AC_DEFINE(HAVE_RL_GETC_FUNCTION, 1,
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[Define if your readline library has the rl_getc_function variable.])
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fi
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if test $ac_cv_lib_readline_readline = yes \
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-a $ac_cv_var_rl_getc_function = no; then
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AC_MSG_WARN([*** libreadline is too old on your system.])
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AC_MSG_WARN([*** You need readline version 2.1 or later.])
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fi
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AC_CHECK_FUNCS(strdup)
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. $srcdir/LIBGUILEREADLINE-VERSION
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AC_SUBST(LIBGUILEREADLINE_MAJOR)
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AC_SUBST(LIBGUILEREADLINE_INTERFACE_CURRENT)
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AC_SUBST(LIBGUILEREADLINE_INTERFACE_REVISION)
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AC_SUBST(LIBGUILEREADLINE_INTERFACE_AGE)
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AC_SUBST(LIBGUILEREADLINE_INTERFACE)
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AC_SUBST(GUILE_EFFECTIVE_VERSION)
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AC_CONFIG_FILES(Makefile ice-9/Makefile)
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AC_OUTPUT
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