From: Jérémie Galarneau Date: Mon, 11 Jan 2021 21:49:22 +0000 (-0500) Subject: Fix: configure: support Autoconf 2.70 X-Git-Tag: v0.13.0~42 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=b72f6acbd36aeb32c9f5345082a8d0bdd779a9aa;p=userspace-rcu.git Fix: configure: support Autoconf 2.70 The newly-released autoconf 2.70 introduces a number of breaking changes [1] and is being rolled-out by some distros. Amongst those changes, the AC_PROG_CC_STDC macro is marked as obsolete and was merged into AC_PROG_CC, which we already use. On 2.70, this results in a warning which we handle as an error. A version check is added to invoke the AC_PROG_CC_STDC macro only when running a pre-2.70 version of autoconf, fixing the issue. Also, the AX_PTHREAD macro makes use of the $as_echo built-in shell variable which no longer exists in 2.70. A patch was submitted to the GNU Autoconf archive in March, but there have been no signs of life given since then [2]. As such, our local copy is updated to the latest version and the patch (which looks fairly straight-forward / safe) is applied. This should minimize changes once we go back to an "official" version of the macro. [1] https://lwn.net/Articles/839395/ [2] https://savannah.gnu.org/patch/?9906 Signed-off-by: Jérémie Galarneau Signed-off-by: Mathieu Desnoyers Change-Id: Id57ad87e63c2d398e3d8b81129f9b867b878e01f --- diff --git a/configure.ac b/configure.ac index f477425..1f499c7 100644 --- a/configure.ac +++ b/configure.ac @@ -44,8 +44,8 @@ AC_ARG_ENABLE([compiler-tls], # Checks for C compiler AC_USE_SYSTEM_EXTENSIONS AC_PROG_CC -AC_PROG_CC_STDC - +# AC_PROG_CC_STDC was merged in AC_PROG_CC in autoconf 2.70 +m4_version_prereq([2.70], [], [AC_PROG_CC_STDC]) AS_IF([test "x$def_compiler_tls" = "xyes"], AC_DEFINE([CONFIG_RCU_TLS], [1]), [:]) # Checks for programs. diff --git a/m4/ax_pthread.m4 b/m4/ax_pthread.m4 index 4920e07..507f182 100644 --- a/m4/ax_pthread.m4 +++ b/m4/ax_pthread.m4 @@ -55,6 +55,7 @@ # # Copyright (c) 2008 Steven G. Johnson # Copyright (c) 2011 Daniel Richard G. +# Copyright (c) 2019 Marc Stevens # # 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 @@ -82,7 +83,7 @@ # modified version of the Autoconf Macro, you may extend this special # exception to the GPL to apply to your modified version as well. -#serial 25 +#serial 27 AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD]) AC_DEFUN([AX_PTHREAD], [ @@ -123,10 +124,12 @@ fi # (e.g. DEC) have both -lpthread and -lpthreads, where one of the # libraries is broken (non-POSIX). -# Create a list of thread flags to try. Items starting with a "-" are -# C compiler flags, and other items are library names, except for "none" -# which indicates that we try without any flags at all, and "pthread-config" -# which is a program returning the flags for the Pth emulation library. +# Create a list of thread flags to try. Items with a "," contain both +# C compiler flags (before ",") and linker flags (after ","). Other items +# starting with a "-" are C compiler flags, and remaining items are +# library names, except for "none" which indicates that we try without +# any flags at all, and "pthread-config" which is a program returning +# the flags for the Pth emulation library. ax_pthread_flags="pthreads none -Kthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config" @@ -194,14 +197,47 @@ case $host_os in # that too in a future libc.) So we'll check first for the # standard Solaris way of linking pthreads (-mt -lpthread). - ax_pthread_flags="-mt,pthread pthread $ax_pthread_flags" + ax_pthread_flags="-mt,-lpthread pthread $ax_pthread_flags" ;; esac +# Are we compiling with Clang? + +AC_CACHE_CHECK([whether $CC is Clang], + [ax_cv_PTHREAD_CLANG], + [ax_cv_PTHREAD_CLANG=no + # Note that Autoconf sets GCC=yes for Clang as well as GCC + if test "x$GCC" = "xyes"; then + AC_EGREP_CPP([AX_PTHREAD_CC_IS_CLANG], + [/* Note: Clang 2.7 lacks __clang_[a-z]+__ */ +# if defined(__clang__) && defined(__llvm__) + AX_PTHREAD_CC_IS_CLANG +# endif + ], + [ax_cv_PTHREAD_CLANG=yes]) + fi + ]) +ax_pthread_clang="$ax_cv_PTHREAD_CLANG" + + # GCC generally uses -pthread, or -pthreads on some platforms (e.g. SPARC) +# Note that for GCC and Clang -pthread generally implies -lpthread, +# except when -nostdlib is passed. +# This is problematic using libtool to build C++ shared libraries with pthread: +# [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25460 +# [2] https://bugzilla.redhat.com/show_bug.cgi?id=661333 +# [3] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=468555 +# To solve this, first try -pthread together with -lpthread for GCC + AS_IF([test "x$GCC" = "xyes"], - [ax_pthread_flags="-pthread -pthreads $ax_pthread_flags"]) + [ax_pthread_flags="-pthread,-lpthread -pthread -pthreads $ax_pthread_flags"]) + +# Clang takes -pthread (never supported any other flag), but we'll try with -lpthread first + +AS_IF([test "x$ax_pthread_clang" = "xyes"], + [ax_pthread_flags="-pthread,-lpthread -pthread"]) + # The presence of a feature test macro requesting re-entrant function # definitions is, on some systems, a strong hint that pthreads support is @@ -224,25 +260,86 @@ AS_IF([test "x$ax_pthread_check_macro" = "x--"], [ax_pthread_check_cond=0], [ax_pthread_check_cond="!defined($ax_pthread_check_macro)"]) -# Are we compiling with Clang? -AC_CACHE_CHECK([whether $CC is Clang], - [ax_cv_PTHREAD_CLANG], - [ax_cv_PTHREAD_CLANG=no - # Note that Autoconf sets GCC=yes for Clang as well as GCC - if test "x$GCC" = "xyes"; then - AC_EGREP_CPP([AX_PTHREAD_CC_IS_CLANG], - [/* Note: Clang 2.7 lacks __clang_[a-z]+__ */ -# if defined(__clang__) && defined(__llvm__) - AX_PTHREAD_CC_IS_CLANG -# endif - ], - [ax_cv_PTHREAD_CLANG=yes]) - fi - ]) -ax_pthread_clang="$ax_cv_PTHREAD_CLANG" +if test "x$ax_pthread_ok" = "xno"; then +for ax_pthread_try_flag in $ax_pthread_flags; do + + case $ax_pthread_try_flag in + none) + AC_MSG_CHECKING([whether pthreads work without any flags]) + ;; + + *,*) + PTHREAD_CFLAGS=`echo $ax_pthread_try_flag | sed "s/^\(.*\),\(.*\)$/\1/"` + PTHREAD_LIBS=`echo $ax_pthread_try_flag | sed "s/^\(.*\),\(.*\)$/\2/"` + AC_MSG_CHECKING([whether pthreads work with "$PTHREAD_CFLAGS" and "$PTHREAD_LIBS"]) + ;; + + -*) + AC_MSG_CHECKING([whether pthreads work with $ax_pthread_try_flag]) + PTHREAD_CFLAGS="$ax_pthread_try_flag" + ;; + + pthread-config) + AC_CHECK_PROG([ax_pthread_config], [pthread-config], [yes], [no]) + AS_IF([test "x$ax_pthread_config" = "xno"], [continue]) + PTHREAD_CFLAGS="`pthread-config --cflags`" + PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`" + ;; + + *) + AC_MSG_CHECKING([for the pthreads library -l$ax_pthread_try_flag]) + PTHREAD_LIBS="-l$ax_pthread_try_flag" + ;; + esac + + ax_pthread_save_CFLAGS="$CFLAGS" + ax_pthread_save_LIBS="$LIBS" + CFLAGS="$CFLAGS $PTHREAD_CFLAGS" + LIBS="$PTHREAD_LIBS $LIBS" + + # Check for various functions. We must include pthread.h, + # since some functions may be macros. (On the Sequent, we + # need a special flag -Kthread to make this header compile.) + # We check for pthread_join because it is in -lpthread on IRIX + # while pthread_create is in libc. We check for pthread_attr_init + # due to DEC craziness with -lpthreads. We check for + # pthread_cleanup_push because it is one of the few pthread + # functions on Solaris that doesn't have a non-functional libc stub. + # We try pthread_create on general principles. + + AC_LINK_IFELSE([AC_LANG_PROGRAM([#include +# if $ax_pthread_check_cond +# error "$ax_pthread_check_macro must be defined" +# endif + static void *some_global = NULL; + static void routine(void *a) + { + /* To avoid any unused-parameter or + unused-but-set-parameter warning. */ + some_global = a; + } + static void *start_routine(void *a) { return a; }], + [pthread_t th; pthread_attr_t attr; + pthread_create(&th, 0, start_routine, 0); + pthread_join(th, 0); + pthread_attr_init(&attr); + pthread_cleanup_push(routine, 0); + pthread_cleanup_pop(0) /* ; */])], + [ax_pthread_ok=yes], + []) + + CFLAGS="$ax_pthread_save_CFLAGS" + LIBS="$ax_pthread_save_LIBS" + + AC_MSG_RESULT([$ax_pthread_ok]) + AS_IF([test "x$ax_pthread_ok" = "xyes"], [break]) + + PTHREAD_LIBS="" + PTHREAD_CFLAGS="" +done +fi -ax_pthread_clang_warning=no # Clang needs special handling, because older versions handle the -pthread # option in a rather... idiosyncratic way @@ -261,11 +358,6 @@ if test "x$ax_pthread_clang" = "xyes"; then # -pthread does define _REENTRANT, and while the Darwin headers # ignore this macro, third-party headers might not.) - PTHREAD_CFLAGS="-pthread" - PTHREAD_LIBS= - - ax_pthread_ok=yes - # However, older versions of Clang make a point of warning the user # that, in an invocation where only linking and no compilation is # taking place, the -pthread option has no effect ("argument unused @@ -294,7 +386,7 @@ if test "x$ax_pthread_clang" = "xyes"; then # step ax_pthread_save_ac_link="$ac_link" ax_pthread_sed='s/conftest\.\$ac_ext/conftest.$ac_objext/g' - ax_pthread_link_step=`$as_echo "$ac_link" | sed "$ax_pthread_sed"` + ax_pthread_link_step=`AS_ECHO(["$ac_link"]) | sed "$ax_pthread_sed"` ax_pthread_2step_ac_link="($ac_compile) && (echo ==== >&5) && ($ax_pthread_link_step)" ax_pthread_save_CFLAGS="$CFLAGS" for ax_pthread_try in '' -Qunused-arguments -Wno-unused-command-line-argument unknown; do @@ -320,78 +412,7 @@ if test "x$ax_pthread_clang" = "xyes"; then fi # $ax_pthread_clang = yes -if test "x$ax_pthread_ok" = "xno"; then -for ax_pthread_try_flag in $ax_pthread_flags; do - - case $ax_pthread_try_flag in - none) - AC_MSG_CHECKING([whether pthreads work without any flags]) - ;; - - -mt,pthread) - AC_MSG_CHECKING([whether pthreads work with -mt -lpthread]) - PTHREAD_CFLAGS="-mt" - PTHREAD_LIBS="-lpthread" - ;; - - -*) - AC_MSG_CHECKING([whether pthreads work with $ax_pthread_try_flag]) - PTHREAD_CFLAGS="$ax_pthread_try_flag" - ;; - - pthread-config) - AC_CHECK_PROG([ax_pthread_config], [pthread-config], [yes], [no]) - AS_IF([test "x$ax_pthread_config" = "xno"], [continue]) - PTHREAD_CFLAGS="`pthread-config --cflags`" - PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`" - ;; - *) - AC_MSG_CHECKING([for the pthreads library -l$ax_pthread_try_flag]) - PTHREAD_LIBS="-l$ax_pthread_try_flag" - ;; - esac - - ax_pthread_save_CFLAGS="$CFLAGS" - ax_pthread_save_LIBS="$LIBS" - CFLAGS="$CFLAGS $PTHREAD_CFLAGS" - LIBS="$PTHREAD_LIBS $LIBS" - - # Check for various functions. We must include pthread.h, - # since some functions may be macros. (On the Sequent, we - # need a special flag -Kthread to make this header compile.) - # We check for pthread_join because it is in -lpthread on IRIX - # while pthread_create is in libc. We check for pthread_attr_init - # due to DEC craziness with -lpthreads. We check for - # pthread_cleanup_push because it is one of the few pthread - # functions on Solaris that doesn't have a non-functional libc stub. - # We try pthread_create on general principles. - - AC_LINK_IFELSE([AC_LANG_PROGRAM([#include -# if $ax_pthread_check_cond -# error "$ax_pthread_check_macro must be defined" -# endif - static void routine(void *a) { a = 0; } - static void *start_routine(void *a) { return a; }], - [pthread_t th; pthread_attr_t attr; - pthread_create(&th, 0, start_routine, 0); - pthread_join(th, 0); - pthread_attr_init(&attr); - pthread_cleanup_push(routine, 0); - pthread_cleanup_pop(0) /* ; */])], - [ax_pthread_ok=yes], - []) - - CFLAGS="$ax_pthread_save_CFLAGS" - LIBS="$ax_pthread_save_LIBS" - - AC_MSG_RESULT([$ax_pthread_ok]) - AS_IF([test "x$ax_pthread_ok" = "xyes"], [break]) - - PTHREAD_LIBS="" - PTHREAD_CFLAGS="" -done -fi # Various other checks: if test "x$ax_pthread_ok" = "xyes"; then