flang/examples/ExternalHelloWorld/external-hello.cpp

   1 #include "flang/Runtime/io-api.h"
   2 #include "flang/Runtime/main.h"
   3 #include "flang/Runtime/stop.h"
   4 #include <cstring>
   5 #include <limits>
   6
   7 using namespace Fortran::runtime::io;
   8
   9 void output1() {
  10   auto io{IONAME(BeginExternalListOutput)()};
  11   const char str[]{"Hello, world!"};
  12   IONAME(OutputAscii)(io, str, std::strlen(str));
  13   IONAME(OutputInteger64)(io, 678);
  14   IONAME(OutputReal64)(io, 0.0);
  15   IONAME(OutputReal64)(io, 2.0 / 3.0);
  16   IONAME(OutputReal64)(io, 1.0e99);
  17   IONAME(OutputReal64)(io, std::numeric_limits<double>::infinity());
  18   IONAME(OutputReal64)(io, -std::numeric_limits<double>::infinity());
  19   IONAME(OutputReal64)(io, std::numeric_limits<double>::quiet_NaN());
  20   IONAME(OutputComplex64)(io, 123.0, -234.0);
  21   IONAME(OutputLogical)(io, false);
  22   IONAME(OutputLogical)(io, true);
  23   IONAME(EndIoStatement)(io);
  24 }
  25
  26 void input1() {
  27   auto io{IONAME(BeginExternalListOutput)()};
  28   const char prompt[]{"Enter an integer value:"};
  29   IONAME(OutputAscii)(io, prompt, std::strlen(prompt));
  30   IONAME(EndIoStatement)(io);
  31
  32   io = IONAME(BeginExternalListInput)();
  33   std::int64_t n{-666};
  34   IONAME(InputInteger)(io, n);
  35   IONAME(EndIoStatement)(io);
  36
  37   io = IONAME(BeginExternalListOutput)();
  38   const char str[]{"Result:"};
  39   IONAME(OutputAscii)(io, str, std::strlen(str));
  40   IONAME(OutputInteger64)(io, n);
  41   IONAME(EndIoStatement)(io);
  42 }
  43
  44 int main(int argc, const char *argv[], const char *envp[]) {
  45   RTNAME(ProgramStart)(argc, argv, envp, nullptr);
  46   output1();
  47   input1();
  48   RTNAME(PauseStatement)();
  49   RTNAME(ProgramEndStatement)();
  50   return 0;
  51 }