def cam3_gen_source(ext, build_dir):
<EOL>fort90source = ['<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',<EOL>'<STR_LIT>',]<EOL>thispath = config.local_path<EOL>sourcelist = []<EOL>sourcelist.append(join(thispath,'<STR_LIT>'))<EOL>for item in fort90source:<EOL><INDENT>sourcelist.append(join(thispath, '<STR_LIT:src>', item))<EOL><DEDENT>sourcelist.append(join(thispath,'<STR_LIT>'))<EOL>try:<EOL><INDENT>config.have_f90c()<EOL>return sourcelist<EOL><DEDENT>except:<EOL><INDENT>print('<STR_LIT>')<EOL>return None<EOL><DEDENT>
Add CAM3 fortran source if Fortran 90 compiler available,
    if no compiler is found do not try to build the extension.