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 "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   InternalDescriptorUnit(Scalar, std::size_t);
30   InternalDescriptorUnit(const Descriptor &, const Terminator &);
31   void EndIoStatement();
32 
33   bool Emit(const char *, std::size_t, IoErrorHandler &);
34   std::optional<char32_t> GetCurrentChar(IoErrorHandler &);
35   bool AdvanceRecord(IoErrorHandler &);
36   void BackspaceRecord(IoErrorHandler &);
37 
38 private:
descriptor()39   Descriptor &descriptor() { return staticDescriptor_.descriptor(); }
descriptor()40   const Descriptor &descriptor() const {
41     return staticDescriptor_.descriptor();
42   }
CurrentRecord()43   Scalar CurrentRecord() const {
44     return descriptor().template ZeroBasedIndexedElement<char>(
45         currentRecordNumber - 1);
46   }
47   StaticDescriptor<maxRank, true /*addendum*/> staticDescriptor_;
48 };
49 
50 extern template class InternalDescriptorUnit<Direction::Output>;
51 extern template class InternalDescriptorUnit<Direction::Input>;
52 } // namespace Fortran::runtime::io
53 #endif // FORTRAN_RUNTIME_IO_INTERNAL_UNIT_H_
54