//===-- 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 "environment.h"
#include "file.h"
#include "format.h"
#include "io-error.h"
#include "io-stmt.h"
#include "lock.h"
#include "terminator.h"
#include "flang/Common/constexpr-bitset.h"
#include "flang/Common/optional.h"
#include "flang/Runtime/memory.h"
#include <cstdlib>
#include <cstring>
#include <flang/Common/variant.h>
namespace Fortran::runtime::io {
class UnitMap;
class ChildIo;
class ExternalFileUnit;
RT_OFFLOAD_VAR_GROUP_BEGIN
// Predefined file units.
extern RT_VAR_ATTRS ExternalFileUnit *defaultInput; // unit 5
extern RT_VAR_ATTRS ExternalFileUnit *defaultOutput; // unit 6
extern RT_VAR_ATTRS ExternalFileUnit *errorOutput; // unit 0 extension
RT_OFFLOAD_VAR_GROUP_END
#if defined(RT_USE_PSEUDO_FILE_UNIT)
// A flavor of OpenFile class that pretends to be a terminal,
// and only provides basic buffering of the output
// in an internal buffer, and Write's the output
// using std::printf(). Since it does not rely on file system
// APIs, it can be used to implement external output
// for offload devices.
class PseudoOpenFile {
public:
using FileOffset = std::int64_t;
RT_API_ATTRS const char *path() const { return nullptr; }
RT_API_ATTRS std::size_t pathLength() const { return 0; }
RT_API_ATTRS void set_path(OwningPtr<char> &&, std::size_t bytes) {}
RT_API_ATTRS bool mayRead() const { return false; }
RT_API_ATTRS bool mayWrite() const { return true; }
RT_API_ATTRS bool mayPosition() const { return false; }
RT_API_ATTRS bool mayAsynchronous() const { return false; }
RT_API_ATTRS void set_mayAsynchronous(bool yes);
// Pretend to be a terminal to force the output
// at the end of IO statement.
RT_API_ATTRS bool isTerminal() const { return true; }
RT_API_ATTRS bool isWindowsTextFile() const { return false; }
RT_API_ATTRS Fortran::common::optional<FileOffset> knownSize() const;
RT_API_ATTRS bool IsConnected() const { return false; }
RT_API_ATTRS void Open(OpenStatus, Fortran::common::optional<Action>,
Position, IoErrorHandler &);
RT_API_ATTRS void Predefine(int fd) {}
RT_API_ATTRS void Close(CloseStatus, IoErrorHandler &);
RT_API_ATTRS std::size_t Read(FileOffset, char *, std::size_t minBytes,
std::size_t maxBytes, IoErrorHandler &);
RT_API_ATTRS std::size_t Write(
FileOffset, const char *, std::size_t, IoErrorHandler &);
RT_API_ATTRS void Truncate(FileOffset, IoErrorHandler &);
RT_API_ATTRS int ReadAsynchronously(
FileOffset, char *, std::size_t, IoErrorHandler &);
RT_API_ATTRS int WriteAsynchronously(
FileOffset, const char *, std::size_t, IoErrorHandler &);
RT_API_ATTRS void Wait(int id, IoErrorHandler &);
RT_API_ATTRS void WaitAll(IoErrorHandler &);
RT_API_ATTRS Position InquirePosition() const;
};
#endif // defined(RT_USE_PSEUDO_FILE_UNIT)
#if !defined(RT_USE_PSEUDO_FILE_UNIT)
using OpenFileClass = OpenFile;
using FileFrameClass = FileFrame<ExternalFileUnit>;
#else // defined(RT_USE_PSEUDO_FILE_UNIT)
using OpenFileClass = PseudoOpenFile;
// Use not so big buffer for the pseudo file unit frame.
using FileFrameClass = FileFrame<ExternalFileUnit, 1024>;
#endif // defined(RT_USE_PSEUDO_FILE_UNIT)
class ExternalFileUnit : public ConnectionState,
public OpenFileClass,
public FileFrameClass {
public:
static constexpr int maxAsyncIds{64 * 16};
explicit RT_API_ATTRS ExternalFileUnit(int unitNumber)
: unitNumber_{unitNumber} {
isUTF8 = executionEnvironment.defaultUTF8;
for (int j{0}; 64 * j < maxAsyncIds; ++j) {
asyncIdAvailable_[j].set();
}
asyncIdAvailable_[0].reset(0);
}
RT_API_ATTRS ~ExternalFileUnit() {}
RT_API_ATTRS int unitNumber() const { return unitNumber_; }
RT_API_ATTRS bool swapEndianness() const { return swapEndianness_; }
RT_API_ATTRS bool createdForInternalChildIo() const {
return createdForInternalChildIo_;
}
static RT_API_ATTRS ExternalFileUnit *LookUp(int unit);
static RT_API_ATTRS ExternalFileUnit *LookUpOrCreate(
int unit, const Terminator &, bool &wasExtant);
static RT_API_ATTRS ExternalFileUnit *LookUpOrCreateAnonymous(int unit,
Direction, Fortran::common::optional<bool> isUnformatted,
IoErrorHandler &);
static RT_API_ATTRS ExternalFileUnit *LookUp(
const char *path, std::size_t pathLen);
static RT_API_ATTRS ExternalFileUnit &CreateNew(int unit, const Terminator &);
static RT_API_ATTRS ExternalFileUnit *LookUpForClose(int unit);
static RT_API_ATTRS ExternalFileUnit &NewUnit(
const Terminator &, bool forChildIo);
static RT_API_ATTRS void CloseAll(IoErrorHandler &);
static RT_API_ATTRS void FlushAll(IoErrorHandler &);
// Returns true if an existing unit was closed
RT_API_ATTRS bool OpenUnit(Fortran::common::optional<OpenStatus>,
Fortran::common::optional<Action>, Position, OwningPtr<char> &&path,
std::size_t pathLength, Convert, IoErrorHandler &);
RT_API_ATTRS bool OpenAnonymousUnit(Fortran::common::optional<OpenStatus>,
Fortran::common::optional<Action>, Position, Convert, IoErrorHandler &);
RT_API_ATTRS void CloseUnit(CloseStatus, IoErrorHandler &);
RT_API_ATTRS void DestroyClosed();
RT_API_ATTRS Iostat SetDirection(Direction);
template <typename A, typename... X>
RT_API_ATTRS IoStatementState &BeginIoStatement(
const Terminator &terminator, X &&...xs) {
// Take lock_ and hold it until EndIoStatement().
#if USE_PTHREADS
if (!lock_.TakeIfNoDeadlock()) {
terminator.Crash("Recursive I/O attempted on unit %d", unitNumber_);
}
#else
lock_.Take();
#endif
A &state{u_.emplace<A>(std::forward<X>(xs)...)};
if constexpr (!std::is_same_v<A, OpenStatementState>) {
state.mutableModes() = ConnectionState::modes;
}
directAccessRecWasSet_ = false;
io_.emplace(state);
return *io_;
}
RT_API_ATTRS bool Emit(
const char *, std::size_t, std::size_t elementBytes, IoErrorHandler &);
RT_API_ATTRS bool Receive(
char *, std::size_t, std::size_t elementBytes, IoErrorHandler &);
RT_API_ATTRS std::size_t GetNextInputBytes(const char *&, IoErrorHandler &);
RT_API_ATTRS std::size_t ViewBytesInRecord(const char *&, bool forward) const;
RT_API_ATTRS bool BeginReadingRecord(IoErrorHandler &);
RT_API_ATTRS void FinishReadingRecord(IoErrorHandler &);
RT_API_ATTRS bool AdvanceRecord(IoErrorHandler &);
RT_API_ATTRS void BackspaceRecord(IoErrorHandler &);
RT_API_ATTRS void FlushOutput(IoErrorHandler &);
RT_API_ATTRS void FlushIfTerminal(IoErrorHandler &);
RT_API_ATTRS void Endfile(IoErrorHandler &);
RT_API_ATTRS void Rewind(IoErrorHandler &);
RT_API_ATTRS void EndIoStatement();
RT_API_ATTRS bool SetStreamPos(
std::int64_t, IoErrorHandler &); // one-based, for POS=
RT_API_ATTRS bool SetDirectRec(
std::int64_t, IoErrorHandler &); // one-based, for REC=
RT_API_ATTRS std::int64_t InquirePos() const {
// 12.6.2.11 defines POS=1 as the beginning of file
return frameOffsetInFile_ + recordOffsetInFrame_ + positionInRecord + 1;
}
RT_API_ATTRS ChildIo *GetChildIo() { return child_.get(); }
RT_API_ATTRS ChildIo &PushChildIo(IoStatementState &);
RT_API_ATTRS void PopChildIo(ChildIo &);
RT_API_ATTRS int GetAsynchronousId(IoErrorHandler &);
RT_API_ATTRS bool Wait(int);
private:
static RT_API_ATTRS UnitMap &CreateUnitMap();
static RT_API_ATTRS UnitMap &GetUnitMap();
RT_API_ATTRS const char *FrameNextInput(IoErrorHandler &, std::size_t);
RT_API_ATTRS void SetPosition(std::int64_t, IoErrorHandler &); // zero-based
RT_API_ATTRS void BeginSequentialVariableUnformattedInputRecord(
IoErrorHandler &);
RT_API_ATTRS void BeginVariableFormattedInputRecord(IoErrorHandler &);
RT_API_ATTRS void BackspaceFixedRecord(IoErrorHandler &);
RT_API_ATTRS void BackspaceVariableUnformattedRecord(IoErrorHandler &);
RT_API_ATTRS void BackspaceVariableFormattedRecord(IoErrorHandler &);
RT_API_ATTRS bool SetVariableFormattedRecordLength();
RT_API_ATTRS void DoImpliedEndfile(IoErrorHandler &);
template <bool ANY_DIR = true, Direction DIR = Direction::Output>
RT_API_ATTRS void DoEndfile(IoErrorHandler &);
RT_API_ATTRS void CommitWrites();
RT_API_ATTRS bool CheckDirectAccess(IoErrorHandler &);
RT_API_ATTRS void HitEndOnRead(IoErrorHandler &);
RT_API_ATTRS std::int32_t ReadHeaderOrFooter(std::int64_t frameOffset);
Lock lock_;
int unitNumber_{-1};
Direction direction_{Direction::Output};
bool impliedEndfile_{false}; // sequential/stream output has taken place
bool beganReadingRecord_{false};
bool anyWriteSinceLastPositioning_{false};
bool directAccessRecWasSet_{false}; // REC= appeared
// 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. So we
// manage the frame and the current record therein separately.
std::int64_t frameOffsetInFile_{0};
std::size_t recordOffsetInFrame_{0}; // of currentRecordNumber
bool swapEndianness_{false};
bool createdForInternalChildIo_{false};
common::BitSet<64> asyncIdAvailable_[maxAsyncIds / 64];
// When a synchronous 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>,
ExternalUnformattedIoStatementState<Direction::Output>,
ExternalUnformattedIoStatementState<Direction::Input>, InquireUnitState,
ExternalMiscIoStatementState, ErroneousIoStatementState>
u_;
// Points to the active alternative (if any) in u_ for use as a Cookie
Fortran::common::optional<IoStatementState> io_;
// A stack of child I/O pseudo-units for defined I/O that have this
// unit number.
OwningPtr<ChildIo> child_;
};
// A pseudo-unit for child I/O statements in defined I/O subroutines;
// it forwards operations to the parent I/O statement, which might also
// be a child I/O statement.
class ChildIo {
public:
RT_API_ATTRS ChildIo(IoStatementState &parent, OwningPtr<ChildIo> &&previous)
: parent_{parent}, previous_{std::move(previous)} {}
RT_API_ATTRS IoStatementState &parent() const { return parent_; }
RT_API_ATTRS void EndIoStatement();
template <typename A, typename... X>
RT_API_ATTRS IoStatementState &BeginIoStatement(X &&...xs) {
A &state{u_.emplace<A>(std::forward<X>(xs)...)};
io_.emplace(state);
return *io_;
}
RT_API_ATTRS OwningPtr<ChildIo> AcquirePrevious() {
return std::move(previous_);
}
RT_API_ATTRS Iostat CheckFormattingAndDirection(bool unformatted, Direction);
private:
IoStatementState &parent_;
OwningPtr<ChildIo> previous_;
std::variant<std::monostate,
ChildFormattedIoStatementState<Direction::Output>,
ChildFormattedIoStatementState<Direction::Input>,
ChildListIoStatementState<Direction::Output>,
ChildListIoStatementState<Direction::Input>,
ChildUnformattedIoStatementState<Direction::Output>,
ChildUnformattedIoStatementState<Direction::Input>, InquireUnitState,
ErroneousIoStatementState, ExternalMiscIoStatementState>
u_;
Fortran::common::optional<IoStatementState> io_;
};
} // namespace Fortran::runtime::io
#endif // FORTRAN_RUNTIME_IO_UNIT_H_
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