[flang][runtime] FLUSH(bad or unconnected unit number) is an error

Some I/O control statements are no-ops when attempted on a bad or
unconnected UNIT=, but the standard says that FLUSH is an error
i

[flang][runtime] FLUSH(bad or unconnected unit number) is an error

Some I/O control statements are no-ops when attempted on a bad or
unconnected UNIT=, but the standard says that FLUSH is an error
in that case.

Differential Revision: https://reviews.llvm.org/D128392

show more ...

[flang] Fix READ/WRITE with POS= on stream units, with refactoring

First, ExternalFileUnit::SetPosition was being used both as a utility
within the class' member functions as well as an API from I/O

[flang] Fix READ/WRITE with POS= on stream units, with refactoring

First, ExternalFileUnit::SetPosition was being used both as a utility
within the class' member functions as well as an API from I/O statement
processing. Make it private, and add APIs for SetStreamPos and SetDirectRec.

Second, ensure that SetStreamPos for POS= positioning in a stream
doesn't leave the current record number and endfile record number
in an arbitrary state. In stream I/O they are used only to manage
end-of-file detection, and shouldn't produce false positive results
from IsAtEnd() after repositioning.

Differential Revision: https://reviews.llvm.org/D128388

show more ...

[flang] Correct implementation of WAIT with no ID

Previous one was returning a bogus error status about a bad WAIT
statement ID number.

Differential Revision: https://reviews.llvm.org/D127979

[flang][runtime] Catch more (all?) negative unit number errors

Fortran does have negative unit numbers -- they show up in child I/O
subroutines for defined I/O and for OPEN(NEWUNIT=) -- but the runt

[flang][runtime] Catch more (all?) negative unit number errors

Fortran does have negative unit numbers -- they show up in child I/O
subroutines for defined I/O and for OPEN(NEWUNIT=) -- but the runtime
needs to catch the cases where a negative unit number that wasn't
generated by the runtime is passed in for OPEN or for an I/O statement
that would ordinarily create an anonymous "fort.NNN" file for a
hitherto unseen unit.

Differential Revision: https://reviews.llvm.org/D127788

show more ...

[flang][runtime] Allow recovery from BACKSPACE(badUnit)

When an unconnected unit number is used in a BACKSPACE statement
with ERR=, IOSTAT=, &/or IOMSG= control specifiers, don't crash,
but let the

[flang][runtime] Allow recovery from BACKSPACE(badUnit)

When an unconnected unit number is used in a BACKSPACE statement
with ERR=, IOSTAT=, &/or IOMSG= control specifiers, don't crash,
but let the program deal with the error.

Differential Revision: https://reviews.llvm.org/D127782

show more ...

[flang][runtime] Don't crash after reporting I/O statement errors

When an I/O statement is known to be in a recoverable error state,
it shouldn't cause a crash later in execution because it's not in

[flang][runtime] Don't crash after reporting I/O statement errors

When an I/O statement is known to be in a recoverable error state,
it shouldn't cause a crash later in execution because it's not in
an expected non-erroneous processing state. Add checking for the
ErroneousIoStatementState variant on paths that might otherwise
lead to runtime crashes.

Differential Revision: https://reviews.llvm.org/D127423

show more ...

[flang][runtime] Better (but still synchronous) support for asynchronous I/O

Track pending "asynchronous" I/O operation IDs so that WAIT statements can
report errors about bad ID numbers.

Lowering

[flang][runtime] Better (but still synchronous) support for asynchronous I/O

Track pending "asynchronous" I/O operation IDs so that WAIT statements can
report errors about bad ID numbers.

Lowering will need to extended to call GetAsynchronousId() for a READ or
WRITE statement with ID=n.

Differential Revision: https://reviews.llvm.org/D127421

show more ...

[flang][runtime] Catch OPEN of connected file

Diagnose OPEN(FILE=f) when f is already connected by the same name to
a distinct external I/O unit.

Differential Revision: https://reviews.llvm.org/D12

[flang][runtime] Catch OPEN of connected file

Diagnose OPEN(FILE=f) when f is already connected by the same name to
a distinct external I/O unit.

Differential Revision: https://reviews.llvm.org/D127035

show more ...

[flang][runtime] Fix deadlock in error recovery

When an external I/O statement is in a recoverable error
state before any data transfers take place (for example,
an unformatted transfer with ERR=/IO

[flang][runtime] Fix deadlock in error recovery

When an external I/O statement is in a recoverable error
state before any data transfers take place (for example,
an unformatted transfer with ERR=/IOSTAT=/IOMSG= attempted on
a formatted unit), ensure that the unit's mutex is still
released at the end of the statement.

Differential Revision: https://reviews.llvm.org/D127032

show more ...

[flang][runtime] INQUIRE(UNIT=666,NUMBER=n) must set n=666

Whether a unit number in an inquire-by-unit statement is valid or not,
it should be the value to which the NUMBER= variable is set, not -1.

[flang][runtime] INQUIRE(UNIT=666,NUMBER=n) must set n=666

Whether a unit number in an inquire-by-unit statement is valid or not,
it should be the value to which the NUMBER= variable is set, not -1.
-1 should be returned to NUMBER= only for an inquire-by-file statement
when the FILE= is not connected to any unit.

Differential Revision: https://reviews.llvm.org/D126145

show more ...

[flang][runtime] Clean up asynchronous I/O APIs

Now that the requirements and implementation of asynchronous I/O are
better understood, adjust their I/O runtime APIs. In particular:
1) Remove the B

[flang][runtime] Clean up asynchronous I/O APIs

Now that the requirements and implementation of asynchronous I/O are
better understood, adjust their I/O runtime APIs. In particular:
1) Remove the BeginAsynchronousOutput/Input APIs; they're not needed,
since any data transfer statement might have ASYNCHRONOUS= and
(if ASYNCHRONOUS='YES') ID= control list specifiers that need to
at least be checked.
2) Add implementations for BeginWait(All) to check for the error
case of a bad unit number and nonzero ID=.
3) Rearrange and comment SetAsynchronous so that it's clear that
it can be called for READ/WRITE as well as for OPEN.

The implementation remains completely synchronous, but should be conforming.
Where opportunities make sense for true asynchronous implementations of
some big block transfers without SIZE= in the future, we'll need to add
a GetAsynchronousId API to capture ID= on a READ or WRITE; add sourceFile
and sourceLine arguments to BeginWait(All) for good error reporting;
track pending operations in unit.h; and add code to force synchronization
to non-asynchronous I/O operations.

Lowering should call SetAsynchronous when ASYNCHRONOUS= appears as
a control list specifier. It should also set ID=x variables to 0
until such time as we support asynchronous operations, if ever.
This patch only removes the removed APIs from lowering.

Differential Revision: https://reviews.llvm.org/D126143

show more ...

[flang][runtime] Don't pad CHARACTER input at end of record unless PAD='YES'

When formatted CHARACTER input runs into the end of an input record,
the runtime usually fills the remainder of the varia

[flang][runtime] Don't pad CHARACTER input at end of record unless PAD='YES'

When formatted CHARACTER input runs into the end of an input record,
the runtime usually fills the remainder of the variable with spaces,
but this should be conditional, and not done when PAD='NO'.

And while here, add some better comments to two members of connection.h
to make their non-obvious relationship more clear.

Differential Revision: https://reviews.llvm.org/D125053

show more ...

[flang] add a static assert in CheckUnitNumberInRangeImpl

Add a check that CheckUnitNumberInRangeImpl is not needlessly instantiated.

Differential Revision: https://reviews.llvm.org/D123285

[flang] Add runtime API to catch unit number out of range

Unit numbers must fit on a default integer. It is however possible that
the user provides the unit number in UNIT with a wider integer type.

[flang] Add runtime API to catch unit number out of range

Unit numbers must fit on a default integer. It is however possible that
the user provides the unit number in UNIT with a wider integer type.
In such case, lowering was previously silently narrowing
the value and passing the result to the BeginXXX runtime entry points.
Cases where the conversion caused overflow were not reported/caught.
Most existing compilers catch these errors and raise an IO error.
Add a CheckUnitNumberInRange runtime API to do the same in f18.

This runtime API has its own error management interface (i.e., does not
use GetIoMsg, EndIo, and EnableHandlers) because the usual error
management requires BeginXXX to be called to set up the error
management. But in this case, the BeginXXX cannot be called since
the bad unit number that would be provided to it overflew (and in the worst
case scenario, the narrowed value could point to a different valid unit
already in use). Hence I decided to make an API that must be called
before the BeginXXX and should trigger the whole BeginXXX/.../EndIoStatement
to be skipped in case the unit number is too big and the user enabled
error recovery.

Note that CheckUnitNumberInRange accepts negative numbers (as long as
they can fit on a default integer), because unit numbers may be negative
if they were created by NEWUNIT.

Differential Revision: https://reviews.llvm.org/D123157

show more ...

[flang] Error recovery improvement in runtime (IOMSG=)

Some refactoring and related fixes for more accurate
user program error recovery in the I/O runtime, especially
for error recovery with IOMSG=

[flang] Error recovery improvement in runtime (IOMSG=)

Some refactoring and related fixes for more accurate
user program error recovery in the I/O runtime, especially
for error recovery with IOMSG= character values.

1) Move any work in an EndIoStatement() implementation
that may raise an error into a new CompleteOperation()
member function. This allows error handling APIs like
GetIoMsg() to complete a pending I/O statement and harvest
any errors that may result.

2) Move the pending error code from ErroneousIoStatementState
to a new pendingError_ data member in IoErrorHandler.
This allows IoErrorHandler::InError() to return a correct
result when there is a pending error that will be recovered
from so that I/O list data transfers don't crash in the meantime.

3) Don't create and leak a unit for a failed OPEN(NEWUNIT=n)
with error recovery, and don't modify 'n'. (Depends on
changes to API call ordering in lowering, in a separate patch;
code was added to ensure that OPEN statement control list
specifiers, e.g. SetFile(), must be passed before GetNewUnit().)

4) Fix the code that calls a form of strerror to fill an
IOMSG= variable so that it actually works for Fortran's
character type: blank fill with no null or newline termination.

Differential Revision: https://reviews.llvm.org/D122036

show more ...

[flang] Improve runtime crash messages

Where possible, I added additional information to the messages to help
programmers figure out what went wrong. I also removed all uses of the word
"bad" from

[flang] Improve runtime crash messages

Where possible, I added additional information to the messages to help
programmers figure out what went wrong. I also removed all uses of the word
"bad" from the messages since (to me) that implies a moral judgement rather
than a programming error. I replaced it with either "invalid" or "unsupported"
where appropriate.

Differential Revision: https://reviews.llvm.org/D121493

show more ...

[flang] Allow data transfer stmt control list errors to be caught

The runtime crashes on several fundamental I/O data transfer statement
control list errors, like list I/O on a direct-access unit, o

[flang] Allow data transfer stmt control list errors to be caught

The runtime crashes on several fundamental I/O data transfer statement
control list errors, like list I/O on a direct-access unit, or
input from a write-only unit, &c. These errors should not be fatal
when ERR= or IOSTAT= are present.

This patch creates a new ErroneousIoStatementState class and
uses it for the state of an I/O statement that is doomed to fail
from these errors. If there is no ERR= label or IOSTAT= variable,
the error will be raised at the end of the statement. Data transfer
operations along the way will be no-op failures.

Differential Revision: https://reviews.llvm.org/D120745

show more ...

[flang] Allow more concurrently open NEWUNIT= values, with recycling

Add a header-only implementation of Briggs & Torczon's fast small
integer set data structure to flang/include/flang/Common, and u

[flang] Allow more concurrently open NEWUNIT= values, with recycling

Add a header-only implementation of Briggs & Torczon's fast small
integer set data structure to flang/include/flang/Common, and use
it in the runtime to manage a pool of Fortran unit numbers with
recycling. This replaces the bit set previously used for that
purpose. The set is initialized on demand with the negations of
all the NEWUNIT= unit numbers that can be returned to any kind
of integer variable.

For programs that require more concurrently open NEWUNIT= unit
numbers than the pool can hold, they are now allocated with a
non-recycling counter. This allows as many open units as the
operating system provides.

Many of the top-line comments in flang/unittests/Runtime had the
wrong path name. I noticed this while adding a unit test for the
fast integer set data structure, and cleaned them up.

Differential Revision: https://reviews.llvm.org/D120685

show more ...

[flang] Debugging of ACCESS='STREAM' I/O (take 2)

Corrects the runtime implementation of I/O on files with
the access mode ACCESS='STREAM'. This is a collection
of edge-case tweaks to ensure that t

[flang] Debugging of ACCESS='STREAM' I/O (take 2)

Corrects the runtime implementation of I/O on files with
the access mode ACCESS='STREAM'. This is a collection
of edge-case tweaks to ensure that the distinctions between
stream and direct/sequential files, unformatted or formatted,
are respected where appropriate.

Moves NextInField() from io-stmt.h to io-stmt.cpp --
it was getting too big to keep in a header.

This patch exposed a problem with the I/O runtime
on Windows and it was reverted. This version also
fixes that problem; files are now opened on Windows
in binary mode to prevent inadvertent insertions of
carriage returns before line feeds, and those line
endings (CR+LF) are now explicitly generated.

Differential Revision: https://reviews.llvm.org/D119015

show more ...

Revert "[flang] Debugging of ACCESS='STREAM' I/O"

This reverts commit be9946b877add0db906090d22840b213c3f41dd2.

This change has caused Flang's Windows buildbot to start failing:
* https://lab.llvm.

Revert "[flang] Debugging of ACCESS='STREAM' I/O"

This reverts commit be9946b877add0db906090d22840b213c3f41dd2.

This change has caused Flang's Windows buildbot to start failing:
* https://lab.llvm.org/buildbot/#/builders/172/builds/7664

show more ...

[flang] Modify right modes for READ/WRITE vs OPEN

When a mode flag is modified (e.g., BLANK='ZERO') in an I/O data transfer
statement, ensure that the right set of mode flags is modified.
There's on

[flang] Modify right modes for READ/WRITE vs OPEN

When a mode flag is modified (e.g., BLANK='ZERO') in an I/O data transfer
statement, ensure that the right set of mode flags is modified.
There's one set of mode flags that are captured by an OPEN
statement and maintained in the connection, and another that
is maintained in an I/O statement state record for local mutability.
Some I/O API routines were unconditionally modifying the persistent
set of flags.

Differential Revision: https://reviews.llvm.org/D118835

show more ...

[flang] Debugging of ACCESS='STREAM' I/O

Corrects the runtime implementation of I/O on files with
the access mode ACCESS='STREAM'. This is a collection
of edge-case tweaks to ensure that the distin

[flang] Debugging of ACCESS='STREAM' I/O

Corrects the runtime implementation of I/O on files with
the access mode ACCESS='STREAM'. This is a collection
of edge-case tweaks to ensure that the distinctions between
stream and direct/sequential files, unformatted or formatted,
are respected where appropriate.
Moves NextInField() from io-stmt.h to io-stmt.cpp --
it was getting too big to keep in a header.

Differential Revision: https://reviews.llvm.org/D118834

show more ...

[flang] Make NEWUNIT= use a range suitable for INTEGER(KIND=1) and recycle unit numbers

Use a bit-set to manage runtime-generated I/O unit numbers, recycle
them after they're closed, and use a range

[flang] Make NEWUNIT= use a range suitable for INTEGER(KIND=1) and recycle unit numbers

Use a bit-set to manage runtime-generated I/O unit numbers, recycle
them after they're closed, and use a range of values that fits in
a minimal-sized integer.

Differential Revision: https://reviews.llvm.org/D118651

show more ...

[flang] Don't drop format string for external child I/O

In user-defined derived type I/O to an external unit, don't
omit the format string from the constructor of ChildFormattedIoStatement.
And incl

[flang] Don't drop format string for external child I/O

In user-defined derived type I/O to an external unit, don't
omit the format string from the constructor of ChildFormattedIoStatement.
And include any user IOMSG text in the crash message of the
parent, if it doesn't catch errors.

Differential Revision: https://reviews.llvm.org/D117903

show more ...

[flang] Allow INQUIRE() on a child unit in user-defined I/O procedure

A procedure that implements a user-defined derived type I/O operation
is allowed to perform an INQUIRE statement on its unit.

D

[flang] Allow INQUIRE() on a child unit in user-defined I/O procedure

A procedure that implements a user-defined derived type I/O operation
is allowed to perform an INQUIRE statement on its unit.

Differential Revision: https://reviews.llvm.org/D117905https://reviews.llvm.org/D117905

show more ...