The Tor Browser / file revision

 dnl This Source Code Form is subject to the terms of the Mozilla Public

 dnl License, v. 2.0. If a copy of the MPL was not distributed with this

 dnl file, You can obtain one at http://mozilla.org/MPL/2.0/.

 dnl check if the build is using lto. This is really primitive and only detects llvm based

 dnl compilers right now.

 AC_DEFUN([MOZ_DOING_LTO],

 [

   cat > conftest.c <<EOF

                   int foo = 1;

 EOF

   $1=no

   if ${CC-cc} ${CFLAGS} -S conftest.c -o conftest.s >/dev/null 2>&1; then

     if grep '^target triple =' conftest.s; then

       $1=yes

     fi

   fi

   rm -f conftest.[cs]

 ])