cant install islpy

[wusheng-ws]

when i install islpy ,there is an error

     isl\isl_multi_templ.c(764): error C2061: syntax error: identifier '__attribute__'
      isl\isl_multi_templ.c(764): error C2059: syntax error: ';'
      isl\isl_multi_templ.c(805): error C2061: syntax error: identifier '__attribute__'
      isl\isl_multi_templ.c(805): error C2059: syntax error: ';'
      isl\isl_multi_templ.c(831): error C2061: syntax error: identifier '__attribute__'
      isl\isl_multi_templ.c(831): error C2059: syntax error: ';'
      isl\isl_multi_explicit_domain.c(182): error C2061: syntax error: identifier '__attribute__'
      isl\isl_multi_explicit_domain.c(182): error C2059: syntax error: ';'
      c:\users\mycomputer\appdata\local\temp\pip-install-t_id55rm\islpy_f0984a0c04274c78bcf7c4ebb0157c45\isl\check_type_range_templ.c(15): warning C4018: '>': signed/unsigned mismatch
      isl\isl_multi_templ.c(506): warning C4018: '<': signed/unsigned mismatch
      isl\isl_multi_templ.c(508): warning C4018: '<': signed/unsigned mismatch
      isl\isl_multi_templ.c(764): error C2061: syntax error: identifier '__attribute__'
      isl\isl_multi_templ.c(764): error C2059: syntax error: ';'
      isl\isl_multi_templ.c(805): error C2061: syntax error: identifier '__attribute__'
      isl\isl_multi_templ.c(805): error C2059: syntax error: ';'
      isl\isl_multi_templ.c(831): error C2061: syntax error: identifier '__attribute__'
      isl\isl_multi_templ.c(831): error C2059: syntax error: ';'
      error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio 14.0\\VC\\BIN\\x86_amd64\\cl.exe' failed with exit code 2

could you please tell me how to fix it