I am trying to use
autoconf to create a
configure script. However, some of the headers I want to check for require additional compiler flags (e.g.
c++11). I can get partly there with the answer here where the relevant lines look like this in the
std=gnu++11 flag isn't passed to the preprocessing step of
AC_CHECK_HEADERS where I end up with the strange result where it is usable but not present:
checking CL/cl2.hpp usability... yes checking CL/cl2.hpp presence... no
Looking in the
config.log shows the following lines:
configure:3423: checking CL/cl2.hpp presence configure:3423: g++ -E conftest.cpp In file included from conftest.cpp:19:0 /usr/include/CL/cl2.hpp:442:2: error #error Visual studio 2013 or another C++11-supported compiler required
where I can clearly see that the C++ flag is not being used. How can I have compiler flags be used in these preprocessor steps?
I can manually get around this by setting the
CXXCPP manually when running
configure but I'd like it to run without the end user needing to know this.
./configure CXXCPP="g++ -E -std=gnu++11"