diff --git a/configure.ac b/configure.ac index 18321bc728..a9f8b6e4ef 100644 --- a/configure.ac +++ b/configure.ac @@ -80,58 +80,53 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [[ AC_MSG_RESULT([$CLANG]) AS_IF([test "x$CLANG" == "xyes"], [CLANG_FLAGS=-Qunused-arguments]) -# We want to check for compiler flag support. Prior to clang v5.1, there was no way to make -# clang's "argument unused" warning fatal. So we invoke the compiler through a -# wrapper script that greps for this message. +# We want to check for compiler flag support. Prior to clang v5.1, there was no +# way to make clang's "argument unused" warning fatal. So we invoke the +# compiler through a wrapper script that greps for this message. saved_CC="$CC" saved_LD="$LD" flag_wrap="$srcdir/scripts/wrap-compiler-for-flag-check" CC="$flag_wrap $CC" LD="$flag_wrap $LD" -AC_DEFUN([check_cflag], - [AX_CHECK_COMPILE_FLAG([$1], [$2], [$3], [-Werror $4])]) -AC_DEFUN([check_ldflag], - [AX_CHECK_LINK_FLAG([$1], [$2], [$3], [-Werror $4])]) - - AC_ARG_ENABLE([hardening], - [AS_HELP_STRING([--disable-hardening], [Disable options to frustrate memory corruption exploits])], - [], - [enable_hardening=yes]) - -HARDEN_CFLAGS="" -HARDEN_LDFLAGS="" -AS_IF([test "x$enable_hardening" == "xyes"], [ + [AS_HELP_STRING([--disable-hardening], + [Disable options to frustrate memory corruption exploits])], + [], [enable_hardening=yes]) + +AC_DEFUN([CHECK_CFLAG], + [AC_LANG_ASSERT(C) + AC_MSG_CHECKING([if $saved_CC supports "$1"]) + old_cflags="$CFLAGS" + CFLAGS=[$1] + AC_TRY_LINK([#include ], + [printf("Hello")], + AC_MSG_RESULT([yes]) + HARDEN_CFLAGS="$HARDEN_CFLAGS [$1]", + AC_MSG_RESULT([no]) + $2 + ) + ]) + +AS_IF([test "x$enable_hardening" == "xyes" -a "x$HOST_OS" != "xwin"], [ # Tell GCC to NOT optimize based on signed arithmetic overflow - check_cflag([-fno-strict-overflow], [HARDEN_CFLAGS="$HARDEN_CFLAGS -fno-strict-overflow"]) + CHECK_CFLAG([-fno-strict-overflow]) # _FORTIFY_SOURCE replaces builtin functions with safer versions. - check_cflag([-D_FORTIFY_SOURCE=2], - [HARDEN_CFLAGS="$HARDEN_CFLAGS -D_FORTIFY_SOURCE=2"]) - - # Use stack-protector-strong if available; if not, fallback to stack-protector-all which - # is considered to be overkill - check_cflag([-fstack-protector-strong], - [STACK_PROTECT="-fstack-protector-strong"], - check_cflag([-fstack-protector-all], - [STACK_PROTECT="-fstack-protector-all"], - [AC_MSG_ERROR([compiler does not support stack protection - use --disable-hardening to override if you understand the risks])] + CHECK_CFLAG([-D_FORTIFY_SOURCE=2]) + + # Use stack-protector-strong if available; if not, fallback to + # stack-protector-all which is considered to be overkill + CHECK_CFLAG([-fstack-protector-strong], + CHECK_CFLAG([-fstack-protector-all], + AC_MSG_ERROR([compiler does appear to support stack protection + - use --disable-hardening to override]) ) ) - check_ldflag([$STACK_PROTECT], - [HARDEN_CFLAGS="$HARDEN_CFLAGS $STACK_PROTECT" - check_cflag([-Wstack-protector], [HARDEN_CFLAGS="$HARDEN_CFLAGS -Wstack-protector"], - [], [$STACK_PROTECT]) - ], - [AC_MSG_ERROR([compiler supports stack protection but linker does not])] - ) - # Enable read only relocations - check_ldflag([-Wl,-z,relro], - [HARDEN_LDFLAGS="$HARDEN_LDFLAGS -Wl,-z,relro" - check_ldflag([-Wl,-z,now], [HARDEN_LDFLAGS="$HARDEN_LDFLAGS -Wl,-z,now"])]) + CHECK_CFLAG([-Wl,-z,relro]) + CHECK_CFLAG([-Wl,-z,now]) ]) # Restore CC, LD diff --git a/m4/ax_check_compile_flag.m4 b/m4/ax_check_compile_flag.m4 deleted file mode 100644 index 51df0c09a7..0000000000 --- a/m4/ax_check_compile_flag.m4 +++ /dev/null @@ -1,74 +0,0 @@ -# =========================================================================== -# http://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html -# =========================================================================== -# -# SYNOPSIS -# -# AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT]) -# -# DESCRIPTION -# -# Check whether the given FLAG works with the current language's compiler -# or gives an error. (Warnings, however, are ignored) -# -# ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on -# success/failure. -# -# If EXTRA-FLAGS is defined, it is added to the current language's default -# flags (e.g. CFLAGS) when the check is done. The check is thus made with -# the flags: "CFLAGS EXTRA-FLAGS FLAG". This can for example be used to -# force the compiler to issue an error when a bad flag is given. -# -# INPUT gives an alternative input source to AC_COMPILE_IFELSE. -# -# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this -# macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG. -# -# LICENSE -# -# Copyright (c) 2008 Guido U. Draheim -# Copyright (c) 2011 Maarten Bosmans -# -# 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 . -# -# As a special exception, the respective Autoconf Macro's copyright owner -# gives unlimited permission to copy, distribute and modify the configure -# scripts that are the output of Autoconf when processing the Macro. You -# need not follow the terms of the GNU General Public License when using -# or distributing such scripts, even though portions of the text of the -# Macro appear in them. The GNU General Public License (GPL) does govern -# all other use of the material that constitutes the Autoconf Macro. -# -# This special exception to the GPL applies to versions of the Autoconf -# Macro released by the Autoconf Archive. When you make and distribute a -# modified version of the Autoconf Macro, you may extend this special -# exception to the GPL to apply to your modified version as well. - -#serial 3 - -AC_DEFUN([AX_CHECK_COMPILE_FLAG], -[AC_PREREQ(2.59)dnl for _AC_LANG_PREFIX -AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl -AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [ - ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS - _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1" - AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])], - [AS_VAR_SET(CACHEVAR,[yes])], - [AS_VAR_SET(CACHEVAR,[no])]) - _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags]) -AS_IF([test x"AS_VAR_GET(CACHEVAR)" = xyes], - [m4_default([$2], :)], - [m4_default([$3], :)]) -AS_VAR_POPDEF([CACHEVAR])dnl -])dnl AX_CHECK_COMPILE_FLAGS diff --git a/m4/ax_check_link_flag.m4 b/m4/ax_check_link_flag.m4 deleted file mode 100644 index db899ddd08..0000000000 --- a/m4/ax_check_link_flag.m4 +++ /dev/null @@ -1,73 +0,0 @@ -# =========================================================================== -# http://www.gnu.org/software/autoconf-archive/ax_check_link_flag.html -# =========================================================================== -# -# SYNOPSIS -# -# AX_CHECK_LINK_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT]) -# -# DESCRIPTION -# -# Check whether the given FLAG works with the linker or gives an error. -# (Warnings, however, are ignored) -# -# ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on -# success/failure. -# -# If EXTRA-FLAGS is defined, it is added to the linker's default flags -# when the check is done. The check is thus made with the flags: "LDFLAGS -# EXTRA-FLAGS FLAG". This can for example be used to force the linker to -# issue an error when a bad flag is given. -# -# INPUT gives an alternative input source to AC_LINK_IFELSE. -# -# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this -# macro in sync with AX_CHECK_{PREPROC,COMPILE}_FLAG. -# -# LICENSE -# -# Copyright (c) 2008 Guido U. Draheim -# Copyright (c) 2011 Maarten Bosmans -# -# 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 . -# -# As a special exception, the respective Autoconf Macro's copyright owner -# gives unlimited permission to copy, distribute and modify the configure -# scripts that are the output of Autoconf when processing the Macro. You -# need not follow the terms of the GNU General Public License when using -# or distributing such scripts, even though portions of the text of the -# Macro appear in them. The GNU General Public License (GPL) does govern -# all other use of the material that constitutes the Autoconf Macro. -# -# This special exception to the GPL applies to versions of the Autoconf -# Macro released by the Autoconf Archive. When you make and distribute a -# modified version of the Autoconf Macro, you may extend this special -# exception to the GPL to apply to your modified version as well. - -#serial 3 - -AC_DEFUN([AX_CHECK_LINK_FLAG], -[AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_ldflags_$4_$1])dnl -AC_CACHE_CHECK([whether the linker accepts $1], CACHEVAR, [ - ax_check_save_flags=$LDFLAGS - LDFLAGS="$LDFLAGS $4 $1" - AC_LINK_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])], - [AS_VAR_SET(CACHEVAR,[yes])], - [AS_VAR_SET(CACHEVAR,[no])]) - LDFLAGS=$ax_check_save_flags]) -AS_IF([test x"AS_VAR_GET(CACHEVAR)" = xyes], - [m4_default([$2], :)], - [m4_default([$3], :)]) -AS_VAR_POPDEF([CACHEVAR])dnl -])dnl AX_CHECK_LINK_FLAGS