flang/runtime/main.cpp

   1 //===-- runtime/main.cpp --------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "flang/Runtime/main.h"
  10 #include "environment.h"
  11 #include "terminator.h"
  12 #include <cfenv>
  13 #include <cstdio>
  14 #include <cstdlib>
  15
  16 static void ConfigureFloatingPoint() {
  17 #ifdef feclearexcept // a macro in some environments; omit std::
  18   feclearexcept(FE_ALL_EXCEPT);
  19 #else
  20   std::feclearexcept(FE_ALL_EXCEPT);
  21 #endif
  22 #ifdef fesetround
  23   fesetround(FE_TONEAREST);
  24 #else
  25   std::fesetround(FE_TONEAREST);
  26 #endif
  27 }
  28
  29 extern "C" {
  30 void RTNAME(ProgramStart)(int argc, const char *argv[], const char *envp[],
  31     const EnvironmentDefaultList *envDefaults) {
  32   std::atexit(Fortran::runtime::NotifyOtherImagesOfNormalEnd);
  33   Fortran::runtime::executionEnvironment.Configure(
  34       argc, argv, envp, envDefaults);
  35   ConfigureFloatingPoint();
  36   // I/O is initialized on demand so that it works for non-Fortran main().
  37 }
  38
  39 void RTNAME(ByteswapOption)() {
  40   if (Fortran::runtime::executionEnvironment.conversion ==
  41       Fortran::runtime::Convert::Unknown) {
  42     // The environment variable overrides the command-line option;
  43     // either of them take precedence over explicit OPEN(CONVERT=) specifiers.
  44     Fortran::runtime::executionEnvironment.conversion =
  45         Fortran::runtime::Convert::Swap;
  46   }
  47 }
  48 }