Ok. I've tried that check :
have_stlport_in_usr="no"
AM_CHECK_STLPORT(
[/usr],
[have_stlport_in_usr="yes"],
[])
if test "x${have_stlport_in_usr} = "xno" ; then
AM_CHECK_STLPORT(
[/usr/local],
[],
[AC_MSG_ERROR("STLport is needed !")])
fi
But I have that error during the execution of configure:
checking stl/config/user_config.h usability... no
checking stl/config/user_config.h presence... no
checking for stl/config/user_config.h... no
configure: WARNING: STLport headers not in /usr/include/stlport
./configure: line 5680: syntax error near unexpected token `"(c'
./configure: line 5680: ` echo $ECHO_N "(cached) $ECHO_C" >&6'