llvm-project/flang/runtime/unit.h

110 lines
3.7 KiB
C++

//===-- runtime/unit.h ------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// Fortran external I/O units
#ifndef FORTRAN_RUNTIME_IO_UNIT_H_
#define FORTRAN_RUNTIME_IO_UNIT_H_
#include "buffer.h"
#include "connection.h"
#include "file.h"
#include "format.h"
#include "io-error.h"
#include "io-stmt.h"
#include "lock.h"
#include "memory.h"
#include "terminator.h"
#include <cstdlib>
#include <cstring>
#include <optional>
#include <variant>
namespace Fortran::runtime::io {
class UnitMap;
class ExternalFileUnit : public ConnectionState,
public OpenFile,
public FileFrame<ExternalFileUnit> {
public:
explicit ExternalFileUnit(int unitNumber) : unitNumber_{unitNumber} {}
int unitNumber() const { return unitNumber_; }
static ExternalFileUnit *LookUp(int unit);
static ExternalFileUnit &LookUpOrCrash(int unit, const Terminator &);
static ExternalFileUnit &LookUpOrCreate(
int unit, const Terminator &, bool *wasExtant = nullptr);
static ExternalFileUnit *LookUpForClose(int unit);
static int NewUnit(const Terminator &);
static void CloseAll(IoErrorHandler &);
void OpenUnit(OpenStatus, Position, OwningPtr<char> &&path,
std::size_t pathLength, IoErrorHandler &);
void CloseUnit(CloseStatus, IoErrorHandler &);
void DestroyClosed();
template <typename A, typename... X>
IoStatementState &BeginIoStatement(X &&... xs) {
// TODO: Child data transfer statements vs. locking
lock_.Take(); // dropped in EndIoStatement()
A &state{u_.emplace<A>(std::forward<X>(xs)...)};
if constexpr (!std::is_same_v<A, OpenStatementState>) {
state.mutableModes() = ConnectionState::modes;
}
io_.emplace(state);
return *io_;
}
bool Emit(const char *, std::size_t bytes, IoErrorHandler &);
std::optional<char32_t> GetCurrentChar(IoErrorHandler &);
void SetLeftTabLimit();
bool AdvanceRecord(IoErrorHandler &);
void BackspaceRecord(IoErrorHandler &);
void FlushIfTerminal(IoErrorHandler &);
void EndIoStatement();
void SetPosition(std::int64_t pos) {
frameOffsetInFile_ = pos;
recordOffsetInFrame_ = 0;
}
private:
static UnitMap &GetUnitMap();
void NextSequentialUnformattedInputRecord(IoErrorHandler &);
void NextSequentialFormattedInputRecord(IoErrorHandler &);
void BackspaceSequentialUnformattedRecord(IoErrorHandler &);
void BackspaceSequentialFormattedRecord(IoErrorHandler &);
int unitNumber_{-1};
bool isReading_{false};
Lock lock_;
// When an I/O statement is in progress on this unit, holds its state.
std::variant<std::monostate, OpenStatementState, CloseStatementState,
ExternalFormattedIoStatementState<Direction::Output>,
ExternalFormattedIoStatementState<Direction::Input>,
ExternalListIoStatementState<Direction::Output>,
ExternalListIoStatementState<Direction::Input>,
UnformattedIoStatementState<Direction::Output>,
UnformattedIoStatementState<Direction::Input>>
u_;
// Points to the active alternative (if any) in u_ for use as a Cookie
std::optional<IoStatementState> io_;
// Subtle: The beginning of the frame can't be allowed to advance
// during a single list-directed READ due to the possibility of a
// multi-record CHARACTER value with a "r*" repeat count.
std::int64_t frameOffsetInFile_{0};
std::int64_t recordOffsetInFrame_{0}; // of currentRecordNumber
};
} // namespace Fortran::runtime::io
#endif // FORTRAN_RUNTIME_IO_UNIT_H_