Implements a near-universal extension in which NAMELIST
input will skip over unrelated namelist groups in the
input stream until the group with the requested name appears.
Differential Revision: https://reviews.llvm.org/D117843
Consistent with previously documented policy, in which
BOZ literals are accepted in non-standard-conforming circumstances
where they can be converted to an unambiguous known numeric type,
allow BOZ literals to be passed as an actual argument in a reference
to a procedure whose explicit interface has a corresponding dummy
argument with a numeric type to which the BOZ literal may be
converted. Improve error messages associated with BOZ literal
actual arguments, too: don't emit multiple errors.
Differential Revision: https://reviews.llvm.org/D117698
Very old (pre-'77 standard) codes would use arrays initialized
with Hollerith literals, typically in DATA, as modifiable
formats.
Differential Revision: https://reviews.llvm.org/D117344
Derived types with SEQUENCE must have data components of sequence
types; but this rule is relaxed as common an extension in the case of
pointer components, whose targets' types are not really relevant
to the implementation requirements of sequence types.
Differential Revision: https://reviews.llvm.org/D117158
It's not conforming to specify the SAVE attribute more than
once for a variable, but it also doesn't hurt anything and
isn't fatal in other Fortran compilers. Downgrade the
message to a warning for better portability.
Differential Revision: https://reviews.llvm.org/D117153
This is nonconformant usage, but widely accepted as an extension.
Downgrade the error message to a warning.
Differential Revision: https://reviews.llvm.org/D117152
We already accept assignments of INTEGER to LOGICAL (& vice versa)
as an extension, but not initialization. Extend initialization
to cover those cases.
(Also fix misspelling in nearby comment as suggested by code reviewer.)
Decouple an inadvertent dependence cycle by moving two
one-line function definitions into a header file.
Differential Revision: https://reviews.llvm.org/D117159
Implements part of the legacy "DEC structures" feature from
VMS Fortran. STRUCTUREs are processed as if they were derived
types with SEQUENCE. DATA-like object entity initialization
is supported as well (e.g., INTEGER FOO/666/) since it was used
for default component initialization in structures. Anonymous
components (named %FILL) are also supported.
These features, and UNION/MAP, were already being parsed.
An omission in the collection of structure field names in the
case of nested structures with entity declarations was fixed
in the parser.
Structures are supported in modules, but this is mostly for
testing purposes. The names of fields in structures accessed
via USE association cannot appear with dot notation in client
code (at least not yet). DEC structures antedate Fortran 90,
so their actual use in applications should not involve modules.
This patch does not implement UNION/MAP, since that feature
would impose difficulties later in lowering them to MLIR types.
In the meantime, if they appear, semantics will issue a
"not yet implemented" error message.
Differential Revision: https://reviews.llvm.org/D117151
RECL= is required for direct access I/O, but is permitted
as well for sequential I/O, where it is defined by the
standard to specify a maximum record (line) length.
The standard does not say what should happen when an
sequential formatted input record appears whose length is
unequal to RECL= when it is specified.
Precedents from other compilers are unclear: one raises an error,
some honor RECL= as an effective truncation, and a few ignore the
situation. On output, all other compilers tested raised an
error when an attempt is made to emit a record longer than RECL=.
This patch treats RECL= as effective truncation on input and
as a hard limit with error on output, and also ensures that
RECL= can be set *longer* than the actual input record lengths.
Differential Revision: https://reviews.llvm.org/D115102
[NFC] As part of using inclusive language within the llvm project, this patch:
- replaces master with main in C++style.md to match the renaming of the master
branch,
- removes master from `FortranIR.md` where it is superfluous,
- renames a logical variable in `pre-fir-tree04.f90` containing master.
Reviewed By: ZarkoCA
Differential Revision: https://reviews.llvm.org/D113923
This is a near-universal language extension; external unit 0
is preconnected to the standard error output.
Differential Revision: https://reviews.llvm.org/D114298
Please note that the updated documentation reflects the design that we are
working towards, but haven't implemented competely yet. We took this approach
in order to provide a more holisitic and complete overview of the design.
In particular, this document assumes that Flang's frontend and compiler
driver can already generate code. This is still work-in-progress and is
being developed on the `fir-dev` branch in the F18 repository [1].
[1] https://github.com/flang-compiler/f18-llvm-project/tree/fir-dev
Differential Revision: https://reviews.llvm.org/D111573
[NFC] As part of using inclusive language within the llvm project,
this patch replaces master with main when referring to `.chm` files.
Reviewed By: teemperor
Differential Revision: https://reviews.llvm.org/D113299
A CHARACTER variable used as an output format may contain
unquoted tab characters, which are treated as if they had
been quoted. This is an extension supported by all other
Fortran compilers to which I have access.
Differential Revision: https://reviews.llvm.org/D112350
Don't try to convert INTEGER argument expressions to the kind of
the dummy argument when performing generic resolution; specific
procedures may be distinguished only by their kinds.
Differential Revision: https://reviews.llvm.org/D112240
Allocatable dummy arguments can be used to distinguish
two specific procedures in a generic interface when
it is the case that exactly one of them is polymorphic
or exactly one of them is unlimited polymorphic. The
standard requires that an actual argument corresponding
to an (unlimited) polymorphic allocatable dummy argument
must also be an (unlimited) polymorphic allocatable, so an
actual argument that's acceptable to one procedure must
necessarily be a bad match for the other.
Differential Revision: https://reviews.llvm.org/D112237
The Fortran 2018 standard defines the concept of simple contiguity
in subclause 9.5.4 as a characteristic of arrays. So that scalars
may also be used in contexts where simply contiguous arrays are
allowed, f18 treats them as single-element arrays that are trivially
contiguous. This patch documents this semantic extension and
also adds comments to the predicate that implements the concept.
Differential Revision: https://reviews.llvm.org/D111679
To get proper wrap-around behavior for the various kind parameter
values of the optional COUNT= and COUNT_MAX= dummy arguments to
the intrinsic subroutine SYSTEM_CLOCK, add an extra argument to
the APIs for lowering to pass the integer kind of the actual argument.
Avoid confusion by requiring that both actual arguments have the same
kind when both are present. The results of the runtime functions
remain std::int64_t and lowering should still convert them before
storing to the actual argument variables.
Rework the implementation a bit to accomodate the dynamic
specification of the kind parameter, and to clean up some coding
issues with preprocessing and templates.
Use the kind of the COUNT=/COUNT_MAX= actual arguments to determine
the clock's resolution, where possible, in conformance with other
Fortran implementations.
Differential Revision: https://reviews.llvm.org/D111281
Add explicit documentation for a couple of cases where the Fortran
standard has been observed to be ambiguous or nonspecific and we've
had to choose the behavior of the implementation from some possible
alternatives (and may be distinct from other implementations).
Differential Revision: https://reviews.llvm.org/D111446
Support the extension intrinsic subroutines EXIT([status]) and ABORT()
in the intrinsic table and runtime support library. Lowering remains
to be done.
Differential Revision: https://reviews.llvm.org/D110741
Added 'this_image()' to the list of functions that are evaluated as intrinsic.
Added IsCoarray functions to determine if an expression is a coarray (corank > 1).
Added save attribute to coarray variables in test file, this_image.f90.
reviewers: klausler, PeteSteinfeld
Differential Revision: https://reviews.llvm.org/D108059
This reverts commit 81f8ad1769.
This seems to break the shared libs build
(linaro-flang-aarch64-sharedlibs bot) with:
undefined reference to `Fortran::semantics::IsCoarray(Fortran::semantics::Symbol const&)
(from tools/flang/lib/Evaluate/CMakeFiles/obj.FortranEvaluate.dir/tools.cpp.o)
When linking lib/libFortranEvaluate.so.14git
Added 'this_image()' to the list of functions that are evaluated as intrinsic.
Added IsCoarray functions to determine if an expression is a coarray (corank > 1).
Added save attribute to coarray variables in test file, this_image.f90.
reviewers: klausler, PeteSteinfeld
Differential Revision: https://reviews.llvm.org/D108059
The index of an implied DO loop in a DATA statement or array
constructor is defined by Fortran 2018 to have scope over its
implied DO loop. This definition is unfortunate, because it
requires the implied DO loop's bounds expressions to be in the
scope of the index variable. Consequently, in code like
integer, parameter :: j = 5
real, save :: a(5) = [(j, j=1, j)]
the upper bound of the loop is a reference to the index variable,
not the parameter in the enclosing scope.
This patch limits the scope of the index variable to the "body"
of the implied DO loop as one would naturally expect, with a warning.
I would have preferred to make this a hard error, but most Fortran
compilers treat this case as f18 now does. If the standard
were to be fixed, the warning could be made optional.
Differential Revision: https://reviews.llvm.org/D108595
This patch removes `f18`, a.k.a. the old driver. It is being replaced
with the new driver, `flang-new`, which has reached feature parity with
`f18` a while ago. This was discussed in [1] and also in [2].
With this change, `FLANG_BUILD_NEW_DRIVER` is no longer needed and is
also deleted. This means that we are making the dependency on Clang permanent
(i.e. it cannot be disabled with a CMake flag).
LIT set-up is updated accordingly. All references to `f18` or `f18.cpp`
are either updated or removed.
The `F18_FC` variable from the `flang` bash script is replaced with
`FLANG_FC`. The former is still supported for backwards compatibility.
[1] https://lists.llvm.org/pipermail/flang-dev/2021-June/000742.html
[2] https://reviews.llvm.org/D103177
Differential Revision: https://reviews.llvm.org/D105811
Like the similar legacy extension FLOAT(), DFLOAT() represents a
conversion from default integer to DOUBLE PRECISION. Rewrite
into a conversion operation.
Differential Revision: https://reviews.llvm.org/D107489
When a WRITE overwrites an endfile record, we need to forget
that there was an endfile record. When doing a BACKSPACE
after an explicit ENDFILE statement, the position afterwards
must be upon the endfile record.
Attempts to join list-directed delimited character input across
record boundaries was due to a bad reading of the standard
and has been deleted, now that the requirements are better understood.
This problem would cause a read attempt past EOF if a delimited
character input value was at the end of a record.
It turns out that delimited list-directed (and NAMELIST) character
output is required to emit contiguous doubled instances of the
delimiter character when it appears in the output value. When
fixed-size records are being emitted, as is the case with internal
output, this is not possible when the problematic character falls
on the last position of a record. No two other Fortran compilers
do the same thing in this situation so there is no good precedent
to follow.
Because it seems least wrong, with this patch we now emit one copy
of the delimiter as the last character of the current record and
another as the first character of the next record. (The
second-least-wrong alternative might be to flag a runtime error,
but that seems harsh since it's not an explicit error in the standard,
and the output may not have to be usable later as input anyway.)
Consequently, the output is not suitable for use as list-directed or
NAMELIST input.
If a later standard were to clarify this case, this behavior will of
course change as needed to conform.
Differential Revision: https://reviews.llvm.org/D106695
Use derived type information tables to drive default component
initialization (when needed), component destruction, and calls to
final subroutines. Perform these operations automatically for
ALLOCATE()/DEALLOCATE() APIs for allocatables, automatics, and
pointers. Add APIs for use in lowering to perform these operations
for non-allocatable/automatic non-pointer variables.
Data pointer component initialization supports arbitrary constant
designators, a F'2008 feature, which may be a first for Fortran
implementations.
Differential Revision: https://reviews.llvm.org/D106297
Flang diverges from the llvm coding style in that it requires braces
around the bodies of if/while/etc statements, even when the body is
a single statement.
This commit adds the readability-braces-around-statements check to
flang's clang-tidy config file. Hopefully the premerge bots will pick it
up and report violations in Phabricator.
We also explicitly disable the check in the directories corresponding to
the Lower and Optimizer libraries, which rely heavily on mlir and llvm
and therefore follow their coding style. Likewise for the tools
directory.
We also fix any outstanding violations in the runtime and in
lib/Semantics.
Differential Revision: https://reviews.llvm.org/D104100
As a benign extension common to other Fortran compilers,
accept BOZ literals in array constructors w/o explicit
types, treating them as integers.
Differential Revision: https://reviews.llvm.org/D103569
Describes how to run the Fortran LLVM Test Suite, specifically the external SPEC CPU 2017 Fortran tests.
Reviewed By: rovka
Differential Revision: https://reviews.llvm.org/D102877
Most Fortran compilers accept the following benign extension,
and it appears in some applications:
SUBROUTINE FOO(A,N)
IMPLICIT NONE
REAL A(N) ! N is used before being typed
INTEGER N
END
Allow it in f18 only for default integer scalar dummy arguments.
Differential Revesion: https://reviews.llvm.org/D96982
Fortran 2018 explicitly permits an ignored type declaration
for the result of a generic intrinsic function. See the comment
added to Semantics/expression.cpp for an explanation of why this
is somewhat dangerous and worthy of a warning.
Differential Revision: https://reviews.llvm.org/D96879
Now that semantics is working, the standard -fsyntax-only option of
GNU and Clang should be used as the name of the option that causes
f18 to just run the front-end. Support both options in f18, silently
accepting the old option as a synonym for the new one (as
preferred by the code owner), and replace all instances of the
old -fparse-only option with -fsyntax-only throughout the source base.
Differential Revision: https://reviews.llvm.org/D95887
Valentin Clement (バレンタイン クレメン)