Don't attempt to include system headers when not required

[SparkiDev]

Description

Some builds don't require system headers: no filesystem and single threaded.

Testing

./configure '--disable-shared' '--disable-filesystem' '--enable-singlethreaded'

Checklist

• added tests
• updated/added doxygen
• updated appropriate READMEs
• Updated manual and documentation

[dgarske]

I believe this would be solved with SINGLE_THREADED and NO_FILESYSTEM. Which headers were being included? What use case is this solving? Is it tied to a support ticket?

For example I still see:

types.h:

#else /* fallback to architecture size_t for pointer size */
    #include <stddef.h> /* included for getting size_t type */
    typedef size_t wc_ptr_t;

types.h:

#else
                #include <stdio.h>
                #define XSNPRINTF snprintf

Also had to add -DWOLFSSL_NO_ATOMICS to get rid of atomics #include <stdatomic.h>.

Just to name a few. I was able to use -save-temps=obj to see the headers getting pulled in.

[SparkiDev]

The customer didn't open a PR, it is part of the Dilithium work.

My concern was that we include other system headers in the alternate branches that aren't related to threading and filesystem. Excluding all system headers is what they want to do.

Would you rahter I changed the condition to single threaded and no filesyetem?

[dgarske]

The customer didn't open a PR, it is part of the Dilithium work.

My concern was that we include other system headers in the alternate branches that aren't related to threading and filesystem. Excluding all system headers is what they want to do.

Would you rahter I changed the condition to single threaded and no filesyetem?

The else case at the bottom already guards on single_threaded and no_filesystem. Are you seeing something besides the else case like USE_WINDOWS_API? If so I think you should just change it to gate this section on those two macros instead of introducing a new macro.

[SparkiDev]

Changed code to not try to include header files when single threaded and no filesystem.