tor/acinclude.m4
Nick Mathewson ce854a8d22 Add -ftrapv to gcc-hardening ... mostly!
We know there are overflows in curve25519-donna-c32, so we'll have
to have that one be fwrapv.

Only apply the asan, ubsan, and trapv options to the code that does
not need to run in constant time.  Those options introduce branches
to the code they instrument.

(These introduced branches should never actually be taken, so it
might _still_ be constant time after all, but branch predictors are
complicated enough that I'm not really confident here. Let's aim for
safety.)

Closes 17983.
2016-05-12 11:21:28 -04:00

286 lines
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dnl Helper macros for Tor configure.ac
dnl Copyright (c) 2001-2004, Roger Dingledine
dnl Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson
dnl Copyright (c) 2007-2008, Roger Dingledine, Nick Mathewson
dnl Copyright (c) 2007-2015, The Tor Project, Inc.
dnl See LICENSE for licensing information
AC_DEFUN([TOR_EXTEND_CODEPATH],
[
if test -d "$1/lib"; then
LDFLAGS="-L$1/lib $LDFLAGS"
else
LDFLAGS="-L$1 $LDFLAGS"
fi
if test -d "$1/include"; then
CPPFLAGS="-I$1/include $CPPFLAGS"
else
CPPFLAGS="-I$1 $CPPFLAGS"
fi
])
AC_DEFUN([TOR_DEFINE_CODEPATH],
[
if test x$1 = "x(system)"; then
TOR_LDFLAGS_$2=""
TOR_CPPFLAGS_$2=""
else
if test -d "$1/lib"; then
TOR_LDFLAGS_$2="-L$1/lib"
TOR_LIBDIR_$2="$1/lib"
else
TOR_LDFLAGS_$2="-L$1"
TOR_LIBDIR_$2="$1"
fi
if test -d "$1/include"; then
TOR_CPPFLAGS_$2="-I$1/include"
else
TOR_CPPFLAGS_$2="-I$1"
fi
fi
AC_SUBST(TOR_CPPFLAGS_$2)
AC_SUBST(TOR_LDFLAGS_$2)
])
dnl 1: flags
dnl 2: try to link too if this is nonempty.
dnl 3: what to do on success compiling
dnl 4: what to do on failure compiling
AC_DEFUN([TOR_TRY_COMPILE_WITH_CFLAGS], [
AS_VAR_PUSHDEF([VAR],[tor_cv_cflags_$1])
AC_CACHE_CHECK([whether the compiler accepts $1], VAR, [
tor_saved_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -pedantic -Werror $1"
AC_TRY_COMPILE([], [return 0;],
[AS_VAR_SET(VAR,yes)],
[AS_VAR_SET(VAR,no)])
if test x$2 != x; then
AS_VAR_PUSHDEF([can_link],[tor_can_link_$1])
AC_TRY_LINK([], [return 0;],
[AS_VAR_SET(can_link,yes)],
[AS_VAR_SET(can_link,no)])
AS_VAR_POPDEF([can_link])
fi
CFLAGS="$tor_saved_CFLAGS"
])
if test x$VAR = xyes; then
$3
else
$4
fi
AS_VAR_POPDEF([VAR])
])
dnl 1:flags
dnl 2:also try to link (yes: non-empty string)
dnl will set yes or no in $tor_can_link_$1 (as modified by AS_VAR_PUSHDEF)
AC_DEFUN([TOR_CHECK_CFLAGS], [
TOR_TRY_COMPILE_WITH_CFLAGS($1, $2, CFLAGS="$CFLAGS $1", /bin/true)
])
dnl 1:flags
dnl 2:extra ldflags
dnl 3:extra libraries
AC_DEFUN([TOR_CHECK_LDFLAGS], [
AS_VAR_PUSHDEF([VAR],[tor_cv_ldflags_$1])
AC_CACHE_CHECK([whether the linker accepts $1], VAR, [
tor_saved_CFLAGS="$CFLAGS"
tor_saved_LDFLAGS="$LDFLAGS"
tor_saved_LIBS="$LIBS"
CFLAGS="$CFLAGS -pedantic -Werror"
LDFLAGS="$LDFLAGS $2 $1"
LIBS="$LIBS $3"
AC_RUN_IFELSE([AC_LANG_PROGRAM([#include <stdio.h>], [fputs("", stdout)])],
[AS_VAR_SET(VAR,yes)],
[AS_VAR_SET(VAR,no)],
[AC_TRY_LINK([], [return 0;],
[AS_VAR_SET(VAR,yes)],
[AS_VAR_SET(VAR,no)])])
CFLAGS="$tor_saved_CFLAGS"
LDFLAGS="$tor_saved_LDFLAGS"
LIBS="$tor_saved_LIBS"
])
if test x$VAR = xyes; then
LDFLAGS="$LDFLAGS $1"
fi
AS_VAR_POPDEF([VAR])
])
dnl 1:libname
AC_DEFUN([TOR_WARN_MISSING_LIB], [
h=""
if test x$2 = xdevpkg; then
h=" headers for"
fi
if test -f /etc/debian_version && test x"$tor_$1_$2_debian" != x; then
AC_WARN([On Debian, you can install$h $1 using "apt-get install $tor_$1_$2_debian"])
if test x"$tor_$1_$2_debian" != x"$tor_$1_devpkg_debian"; then
AC_WARN([ You will probably need $tor_$1_devpkg_debian too.])
fi
fi
if test -f /etc/fedora-release && test x"$tor_$1_$2_redhat" != x; then
AC_WARN([On Fedora, you can install$h $1 using "dnf install $tor_$1_$2_redhat"])
if test x"$tor_$1_$2_redhat" != x"$tor_$1_devpkg_redhat"; then
AC_WARN([ You will probably need to install $tor_$1_devpkg_redhat too.])
fi
else
if test -f /etc/redhat-release && test x"$tor_$1_$2_redhat" != x; then
AC_WARN([On most Redhat-based systems, you can get$h $1 by installing the $tor_$1_$2_redhat RPM package])
if test x"$tor_$1_$2_redhat" != x"$tor_$1_devpkg_redhat"; then
AC_WARN([ You will probably need to install $tor_$1_devpkg_redhat too.])
fi
fi
fi
])
dnl Look for a library, and its associated includes, and how to link
dnl against it.
dnl
dnl TOR_SEARCH_LIBRARY(1:libname, 2:IGNORED, 3:linkargs, 4:headers,
dnl 5:prototype,
dnl 6:code, 7:IGNORED, 8:searchextra)
dnl
dnl Special variables:
dnl ALT_{libname}_WITHVAL -- another possible value for --with-$1-dir.
dnl Used to support renaming --with-ssl-dir to --with-openssl-dir
dnl
AC_DEFUN([TOR_SEARCH_LIBRARY], [
try$1dir=""
AC_ARG_WITH($1-dir,
AS_HELP_STRING(--with-$1-dir=PATH, [specify path to $1 installation]),
[
if test x$withval != xno ; then
try$1dir="$withval"
fi
])
if test "x$try$1dir" = x && test "x$ALT_$1_WITHVAL" != x ; then
try$1dir="$ALT_$1_WITHVAL"
fi
tor_saved_LIBS="$LIBS"
tor_saved_LDFLAGS="$LDFLAGS"
tor_saved_CPPFLAGS="$CPPFLAGS"
AC_CACHE_CHECK([for $1 directory], tor_cv_library_$1_dir, [
tor_$1_dir_found=no
tor_$1_any_linkable=no
for tor_trydir in "$try$1dir" "(system)" "$prefix" /usr/local /usr/pkg $8; do
LDFLAGS="$tor_saved_LDFLAGS"
LIBS="$tor_saved_LIBS $3"
CPPFLAGS="$tor_saved_CPPFLAGS"
if test -z "$tor_trydir" ; then
continue;
fi
# Skip the directory if it isn't there.
if test ! -d "$tor_trydir" && test "$tor_trydir" != "(system)"; then
continue;
fi
# If this isn't blank, try adding the directory (or appropriate
# include/libs subdirectories) to the command line.
if test "$tor_trydir" != "(system)"; then
TOR_EXTEND_CODEPATH($tor_trydir)
fi
# Can we link against (but not necessarily run, or find the headers for)
# the binary?
AC_LINK_IFELSE([AC_LANG_PROGRAM([$5], [$6])],
[linkable=yes], [linkable=no])
if test "$linkable" = yes; then
tor_$1_any_linkable=yes
# Okay, we can link against it. Can we find the headers?
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([$4], [$6])],
[buildable=yes], [buildable=no])
if test "$buildable" = yes; then
tor_cv_library_$1_dir=$tor_trydir
tor_$1_dir_found=yes
break
fi
fi
done
if test "$tor_$1_dir_found" = no; then
if test "$tor_$1_any_linkable" = no ; then
AC_MSG_WARN([Could not find a linkable $1. If you have it installed somewhere unusual, you can specify an explicit path using --with-$1-dir])
TOR_WARN_MISSING_LIB($1, pkg)
AC_MSG_ERROR([Missing libraries; unable to proceed.])
else
AC_MSG_WARN([We found the libraries for $1, but we could not find the C header files. You may need to install a devel package.])
TOR_WARN_MISSING_LIB($1, devpkg)
AC_MSG_ERROR([Missing headers; unable to proceed.])
fi
fi
LDFLAGS="$tor_saved_LDFLAGS"
LIBS="$tor_saved_LIBS"
CPPFLAGS="$tor_saved_CPPFLAGS"
]) dnl end cache check
LIBS="$LIBS $3"
if test "$tor_cv_library_$1_dir" != "(system)"; then
TOR_EXTEND_CODEPATH($tor_cv_library_$1_dir)
fi
TOR_DEFINE_CODEPATH($tor_cv_library_$1_dir, $1)
if test "$cross_compiling" != yes; then
AC_CACHE_CHECK([whether we need extra options to link $1],
tor_cv_library_$1_linker_option, [
orig_LDFLAGS="$LDFLAGS"
runs=no
linked_with=nothing
if test -d "$tor_cv_library_$1_dir/lib"; then
tor_trydir="$tor_cv_library_$1_dir/lib"
else
tor_trydir="$tor_cv_library_$1_dir"
fi
for tor_tryextra in "(none)" "-Wl,-R$tor_trydir" "-R$tor_trydir" \
"-Wl,-rpath,$tor_trydir" ; do
if test "$tor_tryextra" = "(none)"; then
LDFLAGS="$orig_LDFLAGS"
else
LDFLAGS="$tor_tryextra $orig_LDFLAGS"
fi
AC_RUN_IFELSE([AC_LANG_PROGRAM([$5], [$6])],
[runnable=yes], [runnable=no])
if test "$runnable" = yes; then
tor_cv_library_$1_linker_option=$tor_tryextra
break
fi
done
if test "$runnable" = no; then
AC_MSG_ERROR([Found linkable $1 in $tor_cv_library_$1_dir, but it does not seem to run, even with -R. Maybe specify another using --with-$1-dir}])
fi
LDFLAGS="$orig_LDFLAGS"
]) dnl end cache check check for extra options.
if test "$tor_cv_library_$1_linker_option" != "(none)" ; then
TOR_LDFLAGS_$1="$TOR_LDFLAGS_$1 $tor_cv_library_$1_linker_option"
fi
fi # cross-compile
LIBS="$tor_saved_LIBS"
LDFLAGS="$tor_saved_LDFLAGS"
CPPFLAGS="$tor_saved_CPPFLAGS"
]) dnl end defun
dnl Check whether the prototype for a function is present or missing.
dnl Apple has a nasty habit of putting functions in their libraries (so that
dnl AC_CHECK_FUNCS passes) but not actually declaring them in the headers.
dnl
dnl TOR_CHECK_PROTYPE(1:functionname, 2:macroname, 2: includes)
AC_DEFUN([TOR_CHECK_PROTOTYPE], [
AC_CACHE_CHECK([for declaration of $1], tor_cv_$1_declared, [
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([$3],[void *ptr= $1 ;])],
tor_cv_$1_declared=yes,tor_cv_$1_declared=no)])
if test x$tor_cv_$1_declared != xno ; then
AC_DEFINE($2, 1,
[Defined if the prototype for $1 seems to be present.])
fi
])