A template argument was hard-coded as the Integer type category
rather than properly forwarding the type category of the data for
type-specific instantiations of total (no DIM=) MAXLOC and MINLOC.
This broke total MAXLOC and MINLOC reductions for real and character
data.
Differential Revision: https://reviews.llvm.org/D124303
This patch adds 2 missing items required for `flang-new` to be able to
generate executables:
1. The Fortran_main runtime library, which implements the main entry
point into Fortran's `PROGRAM` in Flang,
2. Extra linker flags to include Fortran runtime libraries (e.g.
Fortran_main).
Fortran_main is the bridge between object files generated by Flang and
the C runtime that takes care of program set-up at system-level. For
every Fortran `PROGRAM`, Flang generates the `_QQmain` function.
Fortran_main implements the C `main` function that simply calls
`_QQmain`.
Additionally, "<driver-path>/../lib" directory is added to the list of
search directories for libraries. This is where the required runtime
libraries are currently located. Note that this the case for the build
directory. We haven't considered installation directories/targets yet.
With this change, you can generate an executable that will print `hello,
world!` as follows:
```bash
$ cat hello.f95
PROGRAM HELLO
write(*, *) "hello, world!"
END PROGRAM HELLO
$ flang-new -flang-experimental-exec hello.f95
./a.out
hello, world!
```
NOTE 1: Fortran_main has to be a static library at all times. It invokes
`_QQmain`, which is the main entry point generated by Flang for the
given input file (you can check this with `flang-new -S hello.f95 -o - |
grep "Qmain"`). This means that Fortran_main has an unresolved
dependency at build time. The linker will allow this for a static
library. However, if Fortran_main was a shared object, then the linker
will produce an error: `undefined symbol: `_QQmain`.
NOTE 2: When Fortran runtime libraries are generated as shared libraries
(excluding Fortran_main, which is always static), you will need to
tell the dynamic linker (by e.g. tweaking LD_LIBRARY_PATH) where to look
for them when invoking the executables. For example:
```bash
LD_LIBRARY_PATH=$LD_LIBRARY_PATH:<flang-build-dir>/lib/ ./a.out
```
NOTE 3: This feature is considered experimental and currently guarded
with a flag: `-flang-experimental-exec`.
Differential Revision: https://reviews.llvm.org/D122008
[1] https://github.com/flang-compiler/f18-llvm-project
CREDITS: Fortran_main was originally written by Eric Schweitz, Jean
Perier, Peter Klausler and Steve Scalpone in the fir-dev` branch in [1].
Co-authored-by: Eric Schweitz <eschweitz@nvidia.com>
Co-authored-by: Peter Klausler <pklausler@nvidia.com>
Co-authored-by: Jean Perier <jperier@nvidia.com>
Co-authored-by: Steve Scalpone <sscalpone@nvidia.com
When PAD='NO' and ADVANCE='YES', we currently signal an input
error when a formatted read tries to go past the end of a record
only when a fixed RECL= is in effect. Other compilers will signal
an error without RECL= too, and that seems like a precedent we
should follow.
Differential Revision: https://reviews.llvm.org/D124301
Ew.d and Dw.d output edit descriptors should respect limitations from
the standard on the value of a kP scale factor with respect to the
digit count (d), at least for values of k other than zero.
Differential Revision: https://reviews.llvm.org/D124300
Blanks are allowed in more places than I allowed for, and
"NAN(foobar)" is allowed to have any parenthesis-balanced
characters in parentheses.
Update: Fix up old sanity test, then avoid usage of "limit" when null.
Differential Revision: https://reviews.llvm.org/D124294
When editing numeric input, always skip leading spaces, even if
BZ mode (or BLANK='ZERO') is in effect; otherwise, a sign character
preceded by blanks will not be recognized.
Differential Revision: https://reviews.llvm.org/D124278
Adds flang/include/flang/Common/log2-visit.h, which defines
a Fortran::common::visit() template function that is a drop-in
replacement for std::visit(). Modifies most use sites in
the front-end and runtime to use common::visit().
The C++ standard mandates that std::visit() have O(1) execution
time, which forces implementations to build dispatch tables.
This new common::visit() is O(log2 N) in the number of alternatives
in a variant<>, but that N tends to be small and so this change
produces a fairly significant improvement in compiler build
memory requirements, a 5-10% improvement in compiler build time,
and a small improvement in compiler execution time.
Building with -DFLANG_USE_STD_VISIT causes common::visit()
to be an alias for std::visit().
Calls to common::visit() with multiple variant arguments
are referred to std::visit(), pending further work.
This change is enabled only for GCC builds with GCC >= 9;
an earlier attempt (D122441) ran into bugs in some versions of
clang and was reverted rather than simply disabled; and it is
not well tested with MSVC. In non-GCC and older GCC builds,
common::visit() is simply an alias for std::visit().
When an error occurs in a formatted sequential output statement
and no output was ever emitted, don't emit a blank record.
This matches the error case behavior of other Fortran compilers.
Differential Revision: https://reviews.llvm.org/D123734
A predicate expression made ENDFILE statements significant
only for sequential files, but it's applicable to formatted
stream output as well.
Differential Revision: https://reviews.llvm.org/D123730
When formatted input (not list-directed or NAMELIST) is in "BZ" mode,
either because a BZ control edit descriptor appeared in a FORMAT or
BLANK="ZERO" appeared in OPEN or READ, input editing must not skip
over blanks before or within the input field.
Differential Revision: https://reviews.llvm.org/D123725
When formatted non-advancing output ends in a control edit descriptor
like nX or Tn or TRn that effectively extends the record, fill any
gap with explicit blanks at the completion of the WRITE.
Differential Revision: https://reviews.llvm.org/D123716
Formatted READs of REAL should convert the exception flags from
the decimal-to-binary conversion library into real runtime FP
exceptions so that they at least show up in the termination message
of a STOP statement.
Differential Revision: https://reviews.llvm.org/D123714
A recent change to implement UTF-8 encoding should have
made the encoding conditional only for CHARACTER(KIND=1)
to enable UTF-8 output vs. Latin-1 or whatever. UTF-8 output
of wider CHARACTER kinds should not be conditional (until we choose
to support UCS-16, maybe). So wider CHARACTER kinds are being
emitted with extra zero bytes; this patch fixes them.
Differential Revision: https://reviews.llvm.org/D123711
Correct the implementation of non-advancing I/O after some testing
to ensure that T tab edit descriptors are not allowed to back up
into positions of a record prior to where it stood at the beginning
of the I/O statement.
Differential Revision: https://reviews.llvm.org/D123709
Most Fortran compilers appear to return the process time
for calls to CPU_TIME, where the flang implementation
prior to this change was returning the time used by the
current thread. This would cause incorrect time being
reported when for example OpenMP is used to share work
across multiple CPUs.
This patch changes the order so the selection of "what
time to return" so that if there is a process time to
report, that is the reported value, and only if that is
not available, the thread time is considerd instead.
Reviewed By: jeanPerier
Differential Revision: https://reviews.llvm.org/D123416
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
Runtime was crashing when an INTEGER passed in formatted output with
a bad edit descriptor even when the user did provide IOSTAT. Flang
is already signaling an error when facing similar error with other
types. Do the same with INTEGERs.
The input case is already signaling an error in the related input error
case.
Differential Revision: https://reviews.llvm.org/D122749
Statically checking for overflow with
if constexpr (sizeof(std::size_t) <= sizeof(std::int64_t)) {
return static_cast<std::int64_t>(length);
}
Doesn't work if `sizeof(std::size_t) == sizeof(std::int64_t)` because std::size_t
is unsigned.
if `length == std::numeric_limits<size_t>` casting it to `int64_t` is going to overflow.
This code would be much simpler if returning a `uint64_t` instead of a signed
value...
Differential Revision: https://reviews.llvm.org/D122705
PointerDeallocate was silently doing nothing because it relied on
Destroy that doe not do anything for Pointers. Add an option to Destroy
in order to destroy pointers.
Add a unit test for PointerDeallocate.
Differential Revision: https://reviews.llvm.org/D122492
STATUS='NEW' and 'REPLACE' require FILE= to be present.
STATUS='SCRATCH' may not appear with FILE=.
These errors are caught at compilation time when constant character
strings are used in an OPEN statement, but the runtime needs
to enforce them as well to catch errors in OPEN statements
with character variables and expressions.
Differential Revision: https://reviews.llvm.org/D122509
Adds flang/include/flang/Common/visit.h, which defines
a Fortran::common::visit() template function that is a drop-in
replacement for std::visit(). Modifies most use sites in
the front-end and runtime to use common::visit().
The C++ standard mandates that std::visit() have O(1) execution
time, which forces implementations to build dispatch tables.
This new common::visit() is O(log2 N) in the number of alternatives
in a variant<>, but that N tends to be small and so this change
produces a fairly significant improvement in compiler build
memory requirements, a 5-10% improvement in compiler build time,
and a small improvement in compiler execution time.
Building with -DFLANG_USE_STD_VISIT causes common::visit()
to be an alias for std::visit().
Calls to common::visit() with multiple variant arguments
are referred to std::visit(), pending further work.
Differential Revision: https://reviews.llvm.org/D122441
To make it easier to find things that are not yet implemented, I'm changing the
messages that appear in the compiler's output to all have the string "not yet
implemented:".
These changes apply to files in the front end. I have another set of changes
to files in the lowering code.
Differential Revision: https://reviews.llvm.org/D122355
Implements UTF-8 encoding and decoding for external units
with OPEN(ENCODING='UTF-8'). This encoding applies to default
CHARACTER values that are not 7-bit ASCII as well as to
the wide CHARACTER kinds 2 and 4. Basic testing is in place
via direct calls to the runtime I/O APIs, but serious checkout
awaits lowering support of the wide CHARACTER kinds.
Differential Revision: https://reviews.llvm.org/D122038
Some I/O error situations are current handled with fatal
runtime asserts, but should be exposed for user program
error recovery.
Differential Revision: https://reviews.llvm.org/D122049
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
In flang/runtime/transformational.cpp, there are many RUNTIME_CHECK assertions
for errors that should have been caught in semantics, but there are alno others
that signify program errors that in principle cannot be detected until
execution. Convert this second group into readable fatal error messages.
Also clean up some missing braces and incorrect printf formats found
along the way.
Differential Revision: https://reviews.llvm.org/D122037
LBOUND must return 1 for an empty dimension, no matter what
explicit expression might appear in a declaration or arrive in
a descriptor.
Differential Revision: https://reviews.llvm.org/D121488
Implement the GET_COMMAND intrinsic.
Add 2 new parameters (sourceFile and line) so we can create a terminator
for RUNTIME_CHECKs.
Differential Revision: https://reviews.llvm.org/D118777
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
The code that computed the extent of a dimension of a
non-allocatable/non-automatic component array during
finalization had a reversed subtraction; fix, and
use variables to make the code a little more readable.
Differential Revision: https://reviews.llvm.org/D121163
Rather than reading default character variables in formatted
input one byte at a time via NextInField(), skip and read
them via blocks of available buffer data. This eliminates
a bottleneck that affected reads of large character values.
(It also exposed a problem with sequential reads with RECL=
set on the OPEN statement, so that's fixed too.)
Differential Revision: https://reviews.llvm.org/D121144
The TARGET argument of ASSOCIATED may be dynamically optional, in which
case ASSOCIATED(POINTER, TARGET) is equal to ASSOCIATED(TARGET).
Make the runtime argument a pointer so that it can detect and handle
arguments that are dynamically optional.
Also fix the runtime to check if TARGET base address is not null and if
its element size is not null to match the requirement of ASSOCIATED
regarding TARGET:
- if TARGET is an object: true iff [..] TARGET is not a zerosized storage sequence
- if TARGET is a POINTER: true iff [..] POINTER and TARGET are associated
Not that ASSOCIATED will also returns false if TARGET is an unallocated allocatable.
This is not described in the standard, but is a unanimous behaviour of
existing compilers.
Differential Revision: https://reviews.llvm.org/D120835
A data transfer statement must have REC= in its control list
if (and only if) the unit was opened with ACCESS='DIRECT'.
The runtime wasn't catching this error, but was just silently
advancing to the next record as if the access were sequential.
Differential Revision: https://reviews.llvm.org/D120838
Advancement to new output lines was taking fixed-sized direct-access
and internal character array element lengths into account, but not
RECL= settings from OPEN statements.
Differential Revision: https://reviews.llvm.org/D120837
The standard explicitly allows a comma to be omitted between a 'P'
edit descriptor and a following numeric edit descriptor (e.g., 1PE10.1),
and before and after a '/' edit descriptor, but otherwise requires them
between edit descriptors. Most implementations, however, only require
commas where they prevent ambiguity, and accept things like 1XI10.
This extension is already assumed by the static FORMAT checker in
semantics. Patch the runtime to behave accordingly.
Differential Revision: https://reviews.llvm.org/D120747
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
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
When the runtime is initializing an instance of a derived type,
don't crash if an allocatable character component has deferred length.
Differential Revision: https://reviews.llvm.org/D119731
There are several checks in the runtime routine for the RESHAPE
intrinsic. Some checks verify things that should have been checked at
compile time while others represent user errors.
This update changes the checks for user errors into calls to "Crash"
which include information about the failing check. This identifies them
as user errors rather than compiler errors.
I also verified that the checks that remain as internal errors are also
checked by the front end. I added a test to the front end's RESHAPE
test to complete the checks.
Differential Revision: https://reviews.llvm.org/D119596
This change adds runtime routines and tests for LBOUND when passed a DIM argument, SIZE, and UBOUND when not passed a DIM argument.
Associated changes for lowering have already been merged into fir-dev.
Differential Revision: https://reviews.llvm.org/D119360
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
Peter Klausler