Peter Klausler 975579bd94
[flang] Fix variable unformatted I/O bug with output after input (#92828)
When reading variable-length unformatted records, the external I/O
library frames the input buffer so that the footer of the previous
record remains in frame. This is done so that a BACKSPACE doesn't have
to do an extra read to get the length of the previous record before
repositioning over it.

When switching from input to output to overwrite or append new records
after reading any, it is necessary to undo this framing of the last word
in the previous record, since the new output isn't going to define it in
the buffer and it'll be overwritten in the filesystem with garbage.
2024-05-23 15:32:14 -07:00

796 lines
27 KiB
C++

//===-- runtime/unit.cpp --------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// Implementation of ExternalFileUnit common for both
// RT_USE_PSEUDO_FILE_UNIT=0 and RT_USE_PSEUDO_FILE_UNIT=1.
//
//===----------------------------------------------------------------------===//
#include "unit.h"
#include "io-error.h"
#include "lock.h"
#include "tools.h"
#include <limits>
#include <utility>
namespace Fortran::runtime::io {
#ifndef FLANG_RUNTIME_NO_GLOBAL_VAR_DEFS
RT_OFFLOAD_VAR_GROUP_BEGIN
RT_VAR_ATTRS ExternalFileUnit *defaultInput{nullptr}; // unit 5
RT_VAR_ATTRS ExternalFileUnit *defaultOutput{nullptr}; // unit 6
RT_VAR_ATTRS ExternalFileUnit *errorOutput{nullptr}; // unit 0 extension
RT_OFFLOAD_VAR_GROUP_END
#endif // FLANG_RUNTIME_NO_GLOBAL_VAR_DEFS
RT_OFFLOAD_API_GROUP_BEGIN
static inline RT_API_ATTRS void SwapEndianness(
char *data, std::size_t bytes, std::size_t elementBytes) {
if (elementBytes > 1) {
auto half{elementBytes >> 1};
for (std::size_t j{0}; j + elementBytes <= bytes; j += elementBytes) {
for (std::size_t k{0}; k < half; ++k) {
RT_DIAG_PUSH
RT_DIAG_DISABLE_CALL_HOST_FROM_DEVICE_WARN
std::swap(data[j + k], data[j + elementBytes - 1 - k]);
RT_DIAG_POP
}
}
}
}
bool ExternalFileUnit::Emit(const char *data, std::size_t bytes,
std::size_t elementBytes, IoErrorHandler &handler) {
auto furthestAfter{std::max(furthestPositionInRecord,
positionInRecord + static_cast<std::int64_t>(bytes))};
if (openRecl) {
// Check for fixed-length record overrun, but allow for
// sequential record termination.
int extra{0};
int header{0};
if (access == Access::Sequential) {
if (isUnformatted.value_or(false)) {
// record header + footer
header = static_cast<int>(sizeof(std::uint32_t));
extra = 2 * header;
} else {
#ifdef _WIN32
if (!isWindowsTextFile()) {
++extra; // carriage return (CR)
}
#endif
++extra; // newline (LF)
}
}
if (furthestAfter > extra + *openRecl) {
handler.SignalError(IostatRecordWriteOverrun,
"Attempt to write %zd bytes to position %jd in a fixed-size record "
"of %jd bytes",
bytes, static_cast<std::intmax_t>(positionInRecord - header),
static_cast<std::intmax_t>(*openRecl));
return false;
}
}
if (recordLength) {
// It is possible for recordLength to have a value now for a
// variable-length output record if the previous operation
// was a BACKSPACE or non advancing input statement.
recordLength.reset();
beganReadingRecord_ = false;
}
if (IsAfterEndfile()) {
handler.SignalError(IostatWriteAfterEndfile);
return false;
}
CheckDirectAccess(handler);
WriteFrame(frameOffsetInFile_, recordOffsetInFrame_ + furthestAfter, handler);
if (positionInRecord > furthestPositionInRecord) {
std::memset(Frame() + recordOffsetInFrame_ + furthestPositionInRecord, ' ',
positionInRecord - furthestPositionInRecord);
}
char *to{Frame() + recordOffsetInFrame_ + positionInRecord};
std::memcpy(to, data, bytes);
if (swapEndianness_) {
SwapEndianness(to, bytes, elementBytes);
}
positionInRecord += bytes;
furthestPositionInRecord = furthestAfter;
anyWriteSinceLastPositioning_ = true;
return true;
}
bool ExternalFileUnit::Receive(char *data, std::size_t bytes,
std::size_t elementBytes, IoErrorHandler &handler) {
RUNTIME_CHECK(handler, direction_ == Direction::Input);
auto furthestAfter{std::max(furthestPositionInRecord,
positionInRecord + static_cast<std::int64_t>(bytes))};
if (furthestAfter > recordLength.value_or(furthestAfter)) {
handler.SignalError(IostatRecordReadOverrun,
"Attempt to read %zd bytes at position %jd in a record of %jd bytes",
bytes, static_cast<std::intmax_t>(positionInRecord),
static_cast<std::intmax_t>(*recordLength));
return false;
}
auto need{recordOffsetInFrame_ + furthestAfter};
auto got{ReadFrame(frameOffsetInFile_, need, handler)};
if (got >= need) {
std::memcpy(data, Frame() + recordOffsetInFrame_ + positionInRecord, bytes);
if (swapEndianness_) {
SwapEndianness(data, bytes, elementBytes);
}
positionInRecord += bytes;
furthestPositionInRecord = furthestAfter;
return true;
} else {
HitEndOnRead(handler);
return false;
}
}
std::size_t ExternalFileUnit::GetNextInputBytes(
const char *&p, IoErrorHandler &handler) {
RUNTIME_CHECK(handler, direction_ == Direction::Input);
std::size_t length{1};
if (auto recl{EffectiveRecordLength()}) {
if (positionInRecord < *recl) {
length = *recl - positionInRecord;
} else {
p = nullptr;
return 0;
}
}
p = FrameNextInput(handler, length);
return p ? length : 0;
}
const char *ExternalFileUnit::FrameNextInput(
IoErrorHandler &handler, std::size_t bytes) {
RUNTIME_CHECK(handler, isUnformatted.has_value() && !*isUnformatted);
if (static_cast<std::int64_t>(positionInRecord + bytes) <=
recordLength.value_or(positionInRecord + bytes)) {
auto at{recordOffsetInFrame_ + positionInRecord};
auto need{static_cast<std::size_t>(at + bytes)};
auto got{ReadFrame(frameOffsetInFile_, need, handler)};
SetVariableFormattedRecordLength();
if (got >= need) {
return Frame() + at;
}
HitEndOnRead(handler);
}
return nullptr;
}
bool ExternalFileUnit::SetVariableFormattedRecordLength() {
if (recordLength || access == Access::Direct) {
return true;
} else if (FrameLength() > recordOffsetInFrame_) {
const char *record{Frame() + recordOffsetInFrame_};
std::size_t bytes{FrameLength() - recordOffsetInFrame_};
if (const char *nl{FindCharacter(record, '\n', bytes)}) {
recordLength = nl - record;
if (*recordLength > 0 && record[*recordLength - 1] == '\r') {
--*recordLength;
}
return true;
}
}
return false;
}
bool ExternalFileUnit::BeginReadingRecord(IoErrorHandler &handler) {
RUNTIME_CHECK(handler, direction_ == Direction::Input);
if (!beganReadingRecord_) {
beganReadingRecord_ = true;
// Don't use IsAtEOF() to check for an EOF condition here, just detect
// it from a failed or short read from the file. IsAtEOF() could be
// wrong for formatted input if actual newline characters had been
// written in-band by previous WRITEs before a REWIND. In fact,
// now that we know that the unit is being used for input (again),
// it's best to reset endfileRecordNumber and ensure IsAtEOF() will
// now be true on return only if it gets set by HitEndOnRead().
endfileRecordNumber.reset();
if (access == Access::Direct) {
CheckDirectAccess(handler);
auto need{static_cast<std::size_t>(recordOffsetInFrame_ + *openRecl)};
auto got{ReadFrame(frameOffsetInFile_, need, handler)};
if (got >= need) {
recordLength = openRecl;
} else {
recordLength.reset();
HitEndOnRead(handler);
}
} else {
if (anyWriteSinceLastPositioning_ && access == Access::Sequential) {
// Most Fortran implementations allow a READ after a WRITE;
// the read then just hits an EOF.
DoEndfile<false, Direction::Input>(handler);
}
recordLength.reset();
RUNTIME_CHECK(handler, isUnformatted.has_value());
if (*isUnformatted) {
if (access == Access::Sequential) {
BeginSequentialVariableUnformattedInputRecord(handler);
}
} else { // formatted sequential or stream
BeginVariableFormattedInputRecord(handler);
}
}
}
RUNTIME_CHECK(handler,
recordLength.has_value() || !IsRecordFile() || handler.InError());
return !handler.InError();
}
void ExternalFileUnit::FinishReadingRecord(IoErrorHandler &handler) {
RUNTIME_CHECK(handler, direction_ == Direction::Input && beganReadingRecord_);
beganReadingRecord_ = false;
if (handler.GetIoStat() == IostatEnd ||
(IsRecordFile() && !recordLength.has_value())) {
// Avoid bogus crashes in END/ERR circumstances; but
// still increment the current record number so that
// an attempted read of an endfile record, followed by
// a BACKSPACE, will still be at EOF.
++currentRecordNumber;
} else if (IsRecordFile()) {
recordOffsetInFrame_ += *recordLength;
if (access != Access::Direct) {
RUNTIME_CHECK(handler, isUnformatted.has_value());
recordLength.reset();
if (isUnformatted.value_or(false)) {
// Retain footer in frame for more efficient BACKSPACE
frameOffsetInFile_ += recordOffsetInFrame_;
recordOffsetInFrame_ = sizeof(std::uint32_t);
} else { // formatted
if (FrameLength() > recordOffsetInFrame_ &&
Frame()[recordOffsetInFrame_] == '\r') {
++recordOffsetInFrame_;
}
if (FrameLength() > recordOffsetInFrame_ &&
Frame()[recordOffsetInFrame_] == '\n') {
++recordOffsetInFrame_;
}
if (!pinnedFrame || mayPosition()) {
frameOffsetInFile_ += recordOffsetInFrame_;
recordOffsetInFrame_ = 0;
}
}
}
++currentRecordNumber;
} else { // unformatted stream
furthestPositionInRecord =
std::max(furthestPositionInRecord, positionInRecord);
frameOffsetInFile_ += recordOffsetInFrame_ + furthestPositionInRecord;
recordOffsetInFrame_ = 0;
}
BeginRecord();
}
bool ExternalFileUnit::AdvanceRecord(IoErrorHandler &handler) {
if (direction_ == Direction::Input) {
FinishReadingRecord(handler);
return BeginReadingRecord(handler);
} else { // Direction::Output
bool ok{true};
RUNTIME_CHECK(handler, isUnformatted.has_value());
positionInRecord = furthestPositionInRecord;
if (access == Access::Direct) {
if (furthestPositionInRecord <
openRecl.value_or(furthestPositionInRecord)) {
// Pad remainder of fixed length record
WriteFrame(
frameOffsetInFile_, recordOffsetInFrame_ + *openRecl, handler);
std::memset(Frame() + recordOffsetInFrame_ + furthestPositionInRecord,
isUnformatted.value_or(false) ? 0 : ' ',
*openRecl - furthestPositionInRecord);
furthestPositionInRecord = *openRecl;
}
} else if (*isUnformatted) {
if (access == Access::Sequential) {
// Append the length of a sequential unformatted variable-length record
// as its footer, then overwrite the reserved first four bytes of the
// record with its length as its header. These four bytes were skipped
// over in BeginUnformattedIO<Output>().
// TODO: Break very large records up into subrecords with negative
// headers &/or footers
std::uint32_t length;
length = furthestPositionInRecord - sizeof length;
ok = ok &&
Emit(reinterpret_cast<const char *>(&length), sizeof length,
sizeof length, handler);
positionInRecord = 0;
ok = ok &&
Emit(reinterpret_cast<const char *>(&length), sizeof length,
sizeof length, handler);
} else {
// Unformatted stream: nothing to do
}
} else if (handler.GetIoStat() != IostatOk &&
furthestPositionInRecord == 0) {
// Error in formatted variable length record, and no output yet; do
// nothing, like most other Fortran compilers do.
return true;
} else {
// Terminate formatted variable length record
const char *lineEnding{"\n"};
std::size_t lineEndingBytes{1};
#ifdef _WIN32
if (!isWindowsTextFile()) {
lineEnding = "\r\n";
lineEndingBytes = 2;
}
#endif
ok = ok && Emit(lineEnding, lineEndingBytes, 1, handler);
}
leftTabLimit.reset();
if (IsAfterEndfile()) {
return false;
}
CommitWrites();
++currentRecordNumber;
if (access != Access::Direct) {
impliedEndfile_ = IsRecordFile();
if (IsAtEOF()) {
endfileRecordNumber.reset();
}
}
return ok;
}
}
void ExternalFileUnit::BackspaceRecord(IoErrorHandler &handler) {
if (access == Access::Direct || !IsRecordFile()) {
handler.SignalError(IostatBackspaceNonSequential,
"BACKSPACE(UNIT=%d) on direct-access file or unformatted stream",
unitNumber());
} else {
if (IsAfterEndfile()) {
// BACKSPACE after explicit ENDFILE
currentRecordNumber = *endfileRecordNumber;
} else if (leftTabLimit && direction_ == Direction::Input) {
// BACKSPACE after non-advancing input
leftTabLimit.reset();
} else {
DoImpliedEndfile(handler);
if (frameOffsetInFile_ + recordOffsetInFrame_ > 0) {
--currentRecordNumber;
if (openRecl && access == Access::Direct) {
BackspaceFixedRecord(handler);
} else {
RUNTIME_CHECK(handler, isUnformatted.has_value());
if (isUnformatted.value_or(false)) {
BackspaceVariableUnformattedRecord(handler);
} else {
BackspaceVariableFormattedRecord(handler);
}
}
}
}
BeginRecord();
anyWriteSinceLastPositioning_ = false;
}
}
void ExternalFileUnit::FlushOutput(IoErrorHandler &handler) {
if (!mayPosition()) {
auto frameAt{FrameAt()};
if (frameOffsetInFile_ >= frameAt &&
frameOffsetInFile_ <
static_cast<std::int64_t>(frameAt + FrameLength())) {
// A Flush() that's about to happen to a non-positionable file
// needs to advance frameOffsetInFile_ to prevent attempts at
// impossible seeks
CommitWrites();
leftTabLimit.reset();
}
}
Flush(handler);
}
void ExternalFileUnit::FlushIfTerminal(IoErrorHandler &handler) {
if (isTerminal()) {
FlushOutput(handler);
}
}
void ExternalFileUnit::Endfile(IoErrorHandler &handler) {
if (access == Access::Direct) {
handler.SignalError(IostatEndfileDirect,
"ENDFILE(UNIT=%d) on direct-access file", unitNumber());
} else if (!mayWrite()) {
handler.SignalError(IostatEndfileUnwritable,
"ENDFILE(UNIT=%d) on read-only file", unitNumber());
} else if (IsAfterEndfile()) {
// ENDFILE after ENDFILE
} else {
DoEndfile(handler);
if (IsRecordFile() && access != Access::Direct) {
// Explicit ENDFILE leaves position *after* the endfile record
RUNTIME_CHECK(handler, endfileRecordNumber.has_value());
currentRecordNumber = *endfileRecordNumber + 1;
}
}
}
void ExternalFileUnit::Rewind(IoErrorHandler &handler) {
if (access == Access::Direct) {
handler.SignalError(IostatRewindNonSequential,
"REWIND(UNIT=%d) on non-sequential file", unitNumber());
} else {
DoImpliedEndfile(handler);
SetPosition(0, handler);
currentRecordNumber = 1;
leftTabLimit.reset();
anyWriteSinceLastPositioning_ = false;
}
}
void ExternalFileUnit::SetPosition(std::int64_t pos, IoErrorHandler &handler) {
frameOffsetInFile_ = pos;
recordOffsetInFrame_ = 0;
if (access == Access::Direct) {
directAccessRecWasSet_ = true;
}
BeginRecord();
}
bool ExternalFileUnit::SetStreamPos(
std::int64_t oneBasedPos, IoErrorHandler &handler) {
if (access != Access::Stream) {
handler.SignalError("POS= may not appear unless ACCESS='STREAM'");
return false;
}
if (oneBasedPos < 1) { // POS=1 is beginning of file (12.6.2.11)
handler.SignalError(
"POS=%zd is invalid", static_cast<std::intmax_t>(oneBasedPos));
return false;
}
// A backwards POS= implies truncation after writing, at least in
// Intel and NAG.
if (static_cast<std::size_t>(oneBasedPos - 1) <
frameOffsetInFile_ + recordOffsetInFrame_) {
DoImpliedEndfile(handler);
}
SetPosition(oneBasedPos - 1, handler);
// We no longer know which record we're in. Set currentRecordNumber to
// a large value from whence we can both advance and backspace.
currentRecordNumber = std::numeric_limits<std::int64_t>::max() / 2;
endfileRecordNumber.reset();
return true;
}
bool ExternalFileUnit::SetDirectRec(
std::int64_t oneBasedRec, IoErrorHandler &handler) {
if (access != Access::Direct) {
handler.SignalError("REC= may not appear unless ACCESS='DIRECT'");
return false;
}
if (!openRecl) {
handler.SignalError("RECL= was not specified");
return false;
}
if (oneBasedRec < 1) {
handler.SignalError(
"REC=%zd is invalid", static_cast<std::intmax_t>(oneBasedRec));
return false;
}
currentRecordNumber = oneBasedRec;
SetPosition((oneBasedRec - 1) * *openRecl, handler);
return true;
}
void ExternalFileUnit::EndIoStatement() {
io_.reset();
u_.emplace<std::monostate>();
lock_.Drop();
}
void ExternalFileUnit::BeginSequentialVariableUnformattedInputRecord(
IoErrorHandler &handler) {
RUNTIME_CHECK(handler, access == Access::Sequential);
std::int32_t header{0}, footer{0};
std::size_t need{recordOffsetInFrame_ + sizeof header};
std::size_t got{ReadFrame(frameOffsetInFile_, need, handler)};
// Try to emit informative errors to help debug corrupted files.
const char *error{nullptr};
if (got < need) {
if (got == recordOffsetInFrame_) {
HitEndOnRead(handler);
} else {
error = "Unformatted variable-length sequential file input failed at "
"record #%jd (file offset %jd): truncated record header";
}
} else {
header = ReadHeaderOrFooter(recordOffsetInFrame_);
recordLength = sizeof header + header; // does not include footer
need = recordOffsetInFrame_ + *recordLength + sizeof footer;
got = ReadFrame(frameOffsetInFile_, need, handler);
if (got < need) {
error = "Unformatted variable-length sequential file input failed at "
"record #%jd (file offset %jd): hit EOF reading record with "
"length %jd bytes";
} else {
footer = ReadHeaderOrFooter(recordOffsetInFrame_ + *recordLength);
if (footer != header) {
error = "Unformatted variable-length sequential file input failed at "
"record #%jd (file offset %jd): record header has length %jd "
"that does not match record footer (%jd)";
}
}
}
if (error) {
handler.SignalError(error, static_cast<std::intmax_t>(currentRecordNumber),
static_cast<std::intmax_t>(frameOffsetInFile_),
static_cast<std::intmax_t>(header), static_cast<std::intmax_t>(footer));
// TODO: error recovery
}
positionInRecord = sizeof header;
}
void ExternalFileUnit::BeginVariableFormattedInputRecord(
IoErrorHandler &handler) {
if (this == defaultInput) {
if (defaultOutput) {
defaultOutput->FlushOutput(handler);
}
if (errorOutput) {
errorOutput->FlushOutput(handler);
}
}
std::size_t length{0};
do {
std::size_t need{length + 1};
length =
ReadFrame(frameOffsetInFile_, recordOffsetInFrame_ + need, handler) -
recordOffsetInFrame_;
if (length < need) {
if (length > 0) {
// final record w/o \n
recordLength = length;
unterminatedRecord = true;
} else {
HitEndOnRead(handler);
}
break;
}
} while (!SetVariableFormattedRecordLength());
}
void ExternalFileUnit::BackspaceFixedRecord(IoErrorHandler &handler) {
RUNTIME_CHECK(handler, openRecl.has_value());
if (frameOffsetInFile_ < *openRecl) {
handler.SignalError(IostatBackspaceAtFirstRecord);
} else {
frameOffsetInFile_ -= *openRecl;
}
}
void ExternalFileUnit::BackspaceVariableUnformattedRecord(
IoErrorHandler &handler) {
std::int32_t header{0};
auto headerBytes{static_cast<std::int64_t>(sizeof header)};
frameOffsetInFile_ += recordOffsetInFrame_;
recordOffsetInFrame_ = 0;
if (frameOffsetInFile_ <= headerBytes) {
handler.SignalError(IostatBackspaceAtFirstRecord);
return;
}
// Error conditions here cause crashes, not file format errors, because the
// validity of the file structure before the current record will have been
// checked informatively in NextSequentialVariableUnformattedInputRecord().
std::size_t got{
ReadFrame(frameOffsetInFile_ - headerBytes, headerBytes, handler)};
if (static_cast<std::int64_t>(got) < headerBytes) {
handler.SignalError(IostatShortRead);
return;
}
recordLength = ReadHeaderOrFooter(0);
if (frameOffsetInFile_ < *recordLength + 2 * headerBytes) {
handler.SignalError(IostatBadUnformattedRecord);
return;
}
frameOffsetInFile_ -= *recordLength + 2 * headerBytes;
auto need{static_cast<std::size_t>(
recordOffsetInFrame_ + sizeof header + *recordLength)};
got = ReadFrame(frameOffsetInFile_, need, handler);
if (got < need) {
handler.SignalError(IostatShortRead);
return;
}
header = ReadHeaderOrFooter(recordOffsetInFrame_);
if (header != *recordLength) {
handler.SignalError(IostatBadUnformattedRecord);
return;
}
}
// There's no portable memrchr(), unfortunately, and strrchr() would
// fail on a record with a NUL, so we have to do it the hard way.
static RT_API_ATTRS const char *FindLastNewline(
const char *str, std::size_t length) {
for (const char *p{str + length}; p >= str; p--) {
if (*p == '\n') {
return p;
}
}
return nullptr;
}
void ExternalFileUnit::BackspaceVariableFormattedRecord(
IoErrorHandler &handler) {
// File offset of previous record's newline
auto prevNL{
frameOffsetInFile_ + static_cast<std::int64_t>(recordOffsetInFrame_) - 1};
if (prevNL < 0) {
handler.SignalError(IostatBackspaceAtFirstRecord);
return;
}
while (true) {
if (frameOffsetInFile_ < prevNL) {
if (const char *p{
FindLastNewline(Frame(), prevNL - 1 - frameOffsetInFile_)}) {
recordOffsetInFrame_ = p - Frame() + 1;
recordLength = prevNL - (frameOffsetInFile_ + recordOffsetInFrame_);
break;
}
}
if (frameOffsetInFile_ == 0) {
recordOffsetInFrame_ = 0;
recordLength = prevNL;
break;
}
frameOffsetInFile_ -= std::min<std::int64_t>(frameOffsetInFile_, 1024);
auto need{static_cast<std::size_t>(prevNL + 1 - frameOffsetInFile_)};
auto got{ReadFrame(frameOffsetInFile_, need, handler)};
if (got < need) {
handler.SignalError(IostatShortRead);
return;
}
}
if (Frame()[recordOffsetInFrame_ + *recordLength] != '\n') {
handler.SignalError(IostatMissingTerminator);
return;
}
if (*recordLength > 0 &&
Frame()[recordOffsetInFrame_ + *recordLength - 1] == '\r') {
--*recordLength;
}
}
void ExternalFileUnit::DoImpliedEndfile(IoErrorHandler &handler) {
if (access != Access::Direct) {
if (!impliedEndfile_ && leftTabLimit && direction_ == Direction::Output) {
// Flush a partial record after non-advancing output
impliedEndfile_ = true;
}
if (impliedEndfile_ && mayPosition()) {
DoEndfile(handler);
}
}
impliedEndfile_ = false;
}
template <bool ANY_DIR, Direction DIR>
void ExternalFileUnit::DoEndfile(IoErrorHandler &handler) {
if (IsRecordFile() && access != Access::Direct) {
furthestPositionInRecord =
std::max(positionInRecord, furthestPositionInRecord);
if (leftTabLimit) { // last I/O was non-advancing
if (access == Access::Sequential && direction_ == Direction::Output) {
if constexpr (ANY_DIR || DIR == Direction::Output) {
// When DoEndfile() is called from BeginReadingRecord(),
// this call to AdvanceRecord() may appear as a recursion
// though it may never happen. Expose the call only
// under the constexpr direction check.
AdvanceRecord(handler);
} else {
// This check always fails if we are here.
RUNTIME_CHECK(handler, direction_ != Direction::Output);
}
} else { // Access::Stream or input
leftTabLimit.reset();
++currentRecordNumber;
}
}
endfileRecordNumber = currentRecordNumber;
}
frameOffsetInFile_ += recordOffsetInFrame_ + furthestPositionInRecord;
recordOffsetInFrame_ = 0;
FlushOutput(handler);
Truncate(frameOffsetInFile_, handler);
TruncateFrame(frameOffsetInFile_, handler);
BeginRecord();
impliedEndfile_ = false;
anyWriteSinceLastPositioning_ = false;
}
template void ExternalFileUnit::DoEndfile(IoErrorHandler &handler);
template void ExternalFileUnit::DoEndfile<false, Direction::Output>(
IoErrorHandler &handler);
template void ExternalFileUnit::DoEndfile<false, Direction::Input>(
IoErrorHandler &handler);
void ExternalFileUnit::CommitWrites() {
frameOffsetInFile_ +=
recordOffsetInFrame_ + recordLength.value_or(furthestPositionInRecord);
recordOffsetInFrame_ = 0;
BeginRecord();
}
bool ExternalFileUnit::CheckDirectAccess(IoErrorHandler &handler) {
if (access == Access::Direct) {
RUNTIME_CHECK(handler, openRecl);
if (!directAccessRecWasSet_) {
handler.SignalError(
"No REC= was specified for a data transfer with ACCESS='DIRECT'");
return false;
}
}
return true;
}
void ExternalFileUnit::HitEndOnRead(IoErrorHandler &handler) {
handler.SignalEnd();
if (IsRecordFile() && access != Access::Direct) {
endfileRecordNumber = currentRecordNumber;
}
}
ChildIo &ExternalFileUnit::PushChildIo(IoStatementState &parent) {
OwningPtr<ChildIo> current{std::move(child_)};
Terminator &terminator{parent.GetIoErrorHandler()};
OwningPtr<ChildIo> next{New<ChildIo>{terminator}(parent, std::move(current))};
child_.reset(next.release());
return *child_;
}
void ExternalFileUnit::PopChildIo(ChildIo &child) {
if (child_.get() != &child) {
child.parent().GetIoErrorHandler().Crash(
"ChildIo being popped is not top of stack");
}
child_.reset(child.AcquirePrevious().release()); // deletes top child
}
std::int32_t ExternalFileUnit::ReadHeaderOrFooter(std::int64_t frameOffset) {
std::int32_t word;
char *wordPtr{reinterpret_cast<char *>(&word)};
std::memcpy(wordPtr, Frame() + frameOffset, sizeof word);
if (swapEndianness_) {
SwapEndianness(wordPtr, sizeof word, sizeof word);
}
return word;
}
void ChildIo::EndIoStatement() {
io_.reset();
u_.emplace<std::monostate>();
}
Iostat ChildIo::CheckFormattingAndDirection(
bool unformatted, Direction direction) {
bool parentIsInput{!parent_.get_if<IoDirectionState<Direction::Output>>()};
bool parentIsFormatted{parentIsInput
? parent_.get_if<FormattedIoStatementState<Direction::Input>>() !=
nullptr
: parent_.get_if<FormattedIoStatementState<Direction::Output>>() !=
nullptr};
bool parentIsUnformatted{!parentIsFormatted};
if (unformatted != parentIsUnformatted) {
return unformatted ? IostatUnformattedChildOnFormattedParent
: IostatFormattedChildOnUnformattedParent;
} else if (parentIsInput != (direction == Direction::Input)) {
return parentIsInput ? IostatChildOutputToInputParent
: IostatChildInputFromOutputParent;
} else {
return IostatOk;
}
}
RT_OFFLOAD_API_GROUP_END
} // namespace Fortran::runtime::io