flang/runtime/internal-unit.h

   1 //===-- runtime/internal-unit.h ---------------------------------*- 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 // Fortran internal I/O "units"
  10
  11 #ifndef FORTRAN_RUNTIME_IO_INTERNAL_UNIT_H_
  12 #define FORTRAN_RUNTIME_IO_INTERNAL_UNIT_H_
  13
  14 #include "connection.h"
  15 #include "flang/Runtime/descriptor.h"
  16 #include <cinttypes>
  17 #include <type_traits>
  18
  19 namespace Fortran::runtime::io {
  20
  21 class IoErrorHandler;
  22
  23 // Points to (but does not own) a CHARACTER scalar or array for internal I/O.
  24 // Does not buffer.
  25 template <Direction DIR> class InternalDescriptorUnit : public ConnectionState {
  26 public:
  27   using Scalar =
  28       std::conditional_t<DIR == Direction::Input, const char *, char *>;
  29   RT_API_ATTRS InternalDescriptorUnit(Scalar, std::size_t chars, int kind);
  30   RT_API_ATTRS InternalDescriptorUnit(const Descriptor &, const Terminator &);
  31
  32   RT_API_ATTRS bool Emit(const char *, std::size_t, IoErrorHandler &);
  33   RT_API_ATTRS std::size_t GetNextInputBytes(const char *&, IoErrorHandler &);
  34   RT_API_ATTRS std::size_t ViewBytesInRecord(const char *&, bool forward) const;
  35   RT_API_ATTRS bool AdvanceRecord(IoErrorHandler &);
  36   RT_API_ATTRS void BackspaceRecord(IoErrorHandler &);
  37   RT_API_ATTRS std::int64_t InquirePos();
  38
  39 private:
  40   RT_API_ATTRS Descriptor &descriptor() {
  41     return staticDescriptor_.descriptor();
  42   }
  43   RT_API_ATTRS const Descriptor &descriptor() const {
  44     return staticDescriptor_.descriptor();
  45   }
  46   RT_API_ATTRS Scalar CurrentRecord() const {
  47     return descriptor().template ZeroBasedIndexedElement<char>(
  48         currentRecordNumber - 1);
  49   }
  50   RT_API_ATTRS void BlankFill(char *, std::size_t);
  51   RT_API_ATTRS void BlankFillOutputRecord();
  52
  53   StaticDescriptor<maxRank, true /*addendum*/> staticDescriptor_;
  54 };
  55
  56 extern template class InternalDescriptorUnit<Direction::Output>;
  57 extern template class InternalDescriptorUnit<Direction::Input>;
  58 } // namespace Fortran::runtime::io
  59 #endif // FORTRAN_RUNTIME_IO_INTERNAL_UNIT_H_