1//===-- lib/runtime/main.cpp ------------------------------------*- C++ -*-===//
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 "flang-rt/runtime/environment.h"
11#include "flang-rt/runtime/terminator.h"
12#include <cfenv>
13#include <cstdio>
14#include <cstdlib>
15
16static 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
29extern "C" {
30void 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
39void 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}
49

source code of flang-rt/lib/runtime/main.cpp