Emit warnings when CHARACTER lengths or array sizes of actual
and dummy arguments mismatch in risky ways.
Differential Revision: https://reviews.llvm.org/D154370
This patch lowers allocatables and pointers named in "private" OpenMP clause.
Reviewed By: kiranchandramohan
Differential Revision: https://reviews.llvm.org/D148570
The soon-to-be-published next revision of the ISO Fortran language standard
contains a couple of breaking changes to previous specifications that may cause
existing programs to silently change their behavior.
For the change that introduces automatic reallocation of deferred length
allocatable character scalar variables when they appear as the targets
of internal WRITE statements, as IOMSG=/ERRMSG= variables, as outputs
of INQUIRE specifiers, or as INTENT(OUT) arguments to intrinsic
procedures, this patch adds an optional portability warning.
Differential Revision: https://reviews.llvm.org/D154242
Per 15.5.2.5 p2, when both a dummy data object and its associated
actual argument are ALLOCATABLE or POINTER, there are rules requiring
that both be unlimited polymorphic if either is, and that both be
polymorphic if either is. The justifications for the first restriction
is that the called procedure might change the type of an unlimited
polymorphic dummy argument, but as this cannot occur for a dummy
argument with INTENT(IN), we can relax the check to an optional
portability warning. The justification for the second restriction
is that some implementations would have to create a type descriptor
to associate a monomorphic allocatable/pointer actual argument with
a polymorphic dummy argument, and that doesn't apply to f18 since we
use descriptors for them anyways.
Relaxing these needless checks allows more library procedures to
use "class(*), dimension(..), pointer, intent(in)" dummy arguments
in explicit interfaces.
Differential Revision: https://reviews.llvm.org/D151941
This patch is to remove the conversion of the actual argument that
is associated with the dummy argument specified with the IGNORE_TKR
directive.
Commit on behalf of @danielcchen
Differential Revision: https://reviews.llvm.org/D151401
I just broke the test llvm-test-suite/Fortran/gfortran/torture/execute/st_function_1.f90
with a recent patch. The bug was obvious, as is the fix, which works, so
I'm just pushing it directly to make the build bots happy.
Establish a set of optional usage warnings, and enable some
only in "-pedantic" mode that, in our subjective experience
with application codes, seem to issue frequently without
indicating usage that really needs to be corrected. By default,
with this patch the compiler should appear to be somewhat less
persnickety but not less informative.
Differential Revision: https://reviews.llvm.org/D150710
Implement semantics for the IGNORE_TKR directive as it is interpreted
by the PGI / NVFORTRAN compiler.
Differential Revision: https://reviews.llvm.org/D148643
/data/llvm-project/flang/lib/Semantics/check-call.cpp🔢29: error: comparison of integers of different signs: 'int' and 'size_type' (aka 'unsigned long') [-Werror,-Wsign-compare]
CHECK(index >= 0 && index < actuals.size());
~~~~~ ^ ~~~~~~~~~~~~~~
/data/llvm-project/flang/include/flang/Common/idioms.h:89:20: note: expanded from macro 'CHECK'
^
1 error generated.
Implements the PowerPC mtfsf and mtfsfi intrinsics as well as introduces semantic error checking code for PowerPC intrinsics
Reviewed By: klausler
Differential Revision: https://reviews.llvm.org/D144876
Consolidate aspects of pointer assignment & structure constructor pointer component
checking from Semantics/assignment.cpp and /expression.cpp into /pointer-assignment.cpp,
and add a warning about data targets that are not definable objects
but not hard errors. Specifically, a structure component pointer component data
target is not allowed to be a USE-associated object in a pure context by a numbered
constraint, but the right-hand side data target of a pointer assignment statement
has no such constraint, and that's the new warning.
Differential Revision: https://reviews.llvm.org/D146581
A positional (non-keyword) actual argument or alternate return label is not
allowed to follow an actual argument with a keyword.
Differential Revision: https://reviews.llvm.org/D146575
When a parameterized derived type has FINAL subroutines, only
those FINAL subroutines whose dummy argument's type matches the
type parameter values of a particular instantiation are relevant
to that instantiation.
Differential Revision: https://reviews.llvm.org/D145741
The test for compatible function results needs to be nearly strict
equality of their types, not the usual actual/dummy type compatibility
test used in other situations. The exceptional case is that assumed
length CHARACTER function results are compatible with explicit length
results of the same kind. In particular, a function returning a
polymorphic pointer is not compatible with a function returning a
monomorphic pointer even of the same declared type.
Differential Revision: https://reviews.llvm.org/D145094
The actual argument associated with a dummy argument with the TARGET attribute is
not required to be itself a target or pointer, or even to be a variable, but in
those cases, any pointer that is associated with the dummy argument during the
execution of the procedure is either going to be invalid afterwards because it
points to temporary storage that has since been deallocated or an optimization
time bomb because it aliases an object that isn't a target. Add warnings for
these cases.
Differential Revision: https://reviews.llvm.org/D145089
There's several sets of circumstances in which a scalar actual argument can be
associated with a dummy argument array in Fortran, but they apply only to "ordinary"
dummy arguments, not those that are allocatables or pointers.
Differential Revision: https://reviews.llvm.org/D143836
When the source or mold of a reference to the intrinsic function TRANSFER()
has a derived type with a direct component that contains a descriptor,
such as an allocatable or a pointer, emit a warning. User programs
should never access descriptors directly.
Differential Revision: https://reviews.llvm.org/D143823
Fortran 2018 defines some flavors of dummy arguments to require exact
matching of character lengths between dummy and actual arguments;
these situations tend to be those in which the interface must be
explicit and a descriptor is involved: assumed shape, assumed rank,
allocatable, and pointer.
Fortran allows an actual argument in other cases to have a longer
length than the dummy argument; as a common extension, we support a
shorter actual argument as well by means of blank padding, but should
emit a warning.
Differential Revision: https://reviews.llvm.org/D143821
When character lengths are known at compilation time, report an error
when a data target with a known length does not match the explicit length
of a pointer that is being associated with it; see 10.2.2.3 paragraph 5.
Differential Revision: https://reviews.llvm.org/D142755
The standard's specification for the ASSOCIATED() intrinsic function
describes its optional second argument (TARGET=) as being required
to be a valid target for a pointer assignment statement in which the
first argument (POINTER=) was the left-hand side. Some Fortran compilers
apparently interpret this text as a requirement that the POINTER= argument
actually be a valid left-hand side to a pointer assignment statement,
and emit an error if it is not so. This particularly affects the
use of an explicit NULL pointer as the first argument.
Such usage is well-defined, benign, useful, and supported by at least
two other compilers, so we should continue to accept it. This patch
adds a portability warning and some documentation.
In order to implement the portability warning in the best way, the
special checks on calls to the ASSOCIATED() intrinsic function have
been moved from intrinsic processing to Semantics/check-calls.cpp,
whence they have access to semantics' toolchest. Special checks for
other intrinsic functions might also migrate in the future in order
to keep them all in one place.
Differential Revision: https://reviews.llvm.org/D142768
When an ELEMENTAL subroutine is erroneously declared with alternate return
arguments, don't crash when checking the ranks of the actual arguments.
Differential Revision: https://reviews.llvm.org/D140143
This patch implements @klausler's suggestion in `llvm-project` [issue #58973](https://github.com/llvm/llvm-project/issues/58973); encountering the `VOLATILE` attribute should produce a __warning__, not a __fatal error__.
When tested on the following Fortran program `snem0601_012_.f90`:
```fortran
module mod
contains
subroutine sub(m6,error)
integer,intent(inout) :: error
integer,volatile :: m6
if (any ((/m6/).ne.(/6/))) &
& then
error = 1
end if
end subroutine
end module
program fe1nvol12
use mod
integer :: error = 0
call sub(6,error)
if (error .ne. 0) then
print *,'NG: snem0601_012'
end if
print *,'pass: snem0601_012'
end program fe1nvol12
```
the following output is produced:
```bash
$ flang-new -fc1 snem0601_012_.f90
/noback/93u/Sandbox/issue_58973_volatile_dummy_arg/snem0601_012_.f90:21:12: warning: actual argument associated with VOLATILE dummy argument 'm6=' is not a variable
call sub(6,error)
^
```
Reviewed By: clementval, klausler
Differential Revision: https://reviews.llvm.org/D139134
Enforce detectable compilation-time violations of restrictions on the
arguments to the TRANSFER() intrinsic function (16.9.163) with
error messages, and mark other potential problems with warnings.
Differential Revision: https://reviews.llvm.org/D139157
19.6.8 forbids using an INTENT(IN) pointer dummy argument in a pointer association
context, and associated such a pointer with a dummy argument of INTENT(IN OUT) or
INTENT(OUT) is a circumstance that needs to be caught as an error.
Differential Revision: https://reviews.llvm.org/D139138
Standard Fortran allows type-bound procedure bindings to only
be called, and disallows them from being used in other contexts
where a procedure name can be: as the target of a procedure pointer
assignment statement, and as an actual argument that corresponds
to a dummy procedure. So long as the interfaces match, there's
no good reason for these uses to be errors, and there some obvious
use cases in polymorphic programming. So emit portability warnings
rather than errors, and document this usage as an extension.
Differential Revision: https://reviews.llvm.org/D139127
Definability checking is unconditionally flagging the use of a polymorphic
variable as an actual argument for a procedure reference in a PURE subprogram
unless the corresponding dummy is INTENT(IN). This isn't necessary, since
an INTENT(OUT) polymorphic dummy is already caught as an error in the definition
of the callee, which must also be PURE; and an INTENT(IN OUT) or intent-free
dummy is allowed to be passed a polymorphic actual in a PURE context, with
any attempt to deallocate it being caught in the callee.
So add a flag to the definability checker to disable the "polymorphic
definition in PURE context" check when using it to check actual arguments.
Differential Revision: https://reviews.llvm.org/D139044
When a scope declares the name and perhaps some characteristics of
an external subprogram using any of the many means that Fortran supplies
for doing such a thing, and that external subprogram's definition is
available, check the local declaration against the external definition.
In particular, if the global definition's interface cannot be called
by means of an implicit interface, ensure that references are via an
explicit and compatible interface.
Further, extend call site checking so that when a local declaration
exists for a known global symbol and the arguments are valid for that
local declaration, the arguments are checked against the global's
interface, just are is already done when no local declaration exists.
Differential Revision: https://reviews.llvm.org/D139042
The infrastructure in semantics that is used to check that the
left-hand sides of normal assignment statements are really definable
variables was not being used to check whether the LHSs of pointer assignments
are modifiable, and so most cases of unmodifiable pointers are left
undiagnosed. Rework the semantics checking for pointer assignments,
NULLIFY statements, pointer dummy arguments, &c. so that cases of
unmodifiable pointers are properly caught. This has been done
by extracting all the various definability checking code that has
been implemented for different contexts in Fortran into one new
facility.
The new consolidated definability checking code returns messages
meant to be attached as "because: " explanations to context-dependent
errors like "left-hand side of assignment is not definable".
These new error message texts and their attached explanations
affect many existing tests, which have been updated. The testing
infrastructure was extended by another patch to properly compare
warnings and explanatory messages, which had been ignored until
recently.
Differential Revision: https://reviews.llvm.org/D136979
Some of the circumstances that require that a procedure have an
explicit interface at a point of call due to a characteristic of
a dummy argument apply to dummy procedures, too.
Differential Revision: https://reviews.llvm.org/D136994
When a dummy argument is a procedure pointer without INTENT(IN),
any actual argument must also be a procedure pointer, whether the
dummy procedure pointer's interface is explicit or not.
Differential Revision: https://reviews.llvm.org/D136989
The code snippet
module m
interface
module subroutine specific
end subroutine
end interface
interface generic
module procedure specific
end interface
end module
elicits a bogus semantic error about "specific" not being an acceptable
module procedure for the generic interface; fix.
Differential Revision: https://reviews.llvm.org/D134402
A NULL() pointer is a valid actual argument for a procedure pointer dummy
argument whose intent is INTENT(IN); it should also be acceptable for a
procedure pointer dummy argument with unspecified intent.
Also make it possible to discern null object pointers from null procedure
pointers, so that an attempt to use one in place of the other in a context
where the distinction matters will still elicit an error.
Differential Revision: https://reviews.llvm.org/D132687
Semantic checking for calls was requiring an actual argument that corresponds
to an ASYNCHRONOUS or VOLATILE dummy argument to be definable, but this is not
a constraint or requirement in the standard and doesn't even make sense
as a warning; these two attributes are "scopable" in the context of BLOCK
constructs. Remove the checks and adjust the tests.
Differential Revision: https://reviews.llvm.org/D132684
The predicate "CanBeCalledViaImplicitInterface()" was returning false for
restricted specific intrinsic functions (e.g., SIN) because their procedure
characteristics have the elemental attribute; this leads to a bogus semantic
error when one attempts to use them as proc-targets in procedure pointer
assignment statements when the left-hand side of the assignment is a procedure
pointer with an implicit interface. However, these restricted specific intrinsic
functions have always been allowed as special cases for such usage -- it is
as if they are elemental when it is necessary for them to be so, but not
when it's a problem.
Differential Revision: https://reviews.llvm.org/D130386
f18 intentionally does not support the spottily-implemented language extension
in which one can pass NULL() for an allocatable dummy argument. This is perhaps
a sanctioned side effect in other compilers of the fact that they pass distinct
"base address" and "descriptor address" physical arguments.
Make the error message in this case more specific to the circumstances, and
add a note to Extensions.md to clarify that this behavior is intended.
(We could, with some effort in lowering, support passing NULL for an INTENT(IN)
allocatable dummy, but let's see whether such nonconforming usage appears
in a real application before spending any more time on it.)
Differential Revision: https://reviews.llvm.org/D130380
Some procedure pointers and EXTERNAL procedures have neither
explicit interfaces nor result types; these procedures are obviously
not known to be functions, but they could be, so semantics must not
assume that they are necessarily subroutines. Refine the procedure
pointer / dummy procedure compatibility check to handle these more
ambiguous cases and not elicit inappropriate error messages.
Differential Revision: https://reviews.llvm.org/D129674
When a Hollerith (or short character) literal is presented as an actual
argument that corresponds to a dummy argument for which a BOZ literal
would be acceptable, treat the Hollerith as if it had been a BOZ
literal in the same way -- and with the same code -- as f18 already
does for the similar extension in DATA statements.
Differential Revision: https://reviews.llvm.org/D126144
As Fortran 2018 15.8.1(3), in a reference to an elemental procedure, if
any argument is an array, each actual argument that corresponds to an
INTENT (OUT) or INTENT (INOUT) dummy argument shall be an array. Add
this semantic check.
Reviewed By: klausler
Differential Revision: https://reviews.llvm.org/D125685
A disassociated procedure pointer is allowed to be passed as an absent
actual argument that corresponds to an optional dummy procedure,
but not NULL(); accept that case as well.
Differential Revision: https://reviews.llvm.org/D125127
Actual arguments whose lengths are less than the expected length
of their corresponding dummy argument are errors; but this needs
to be refined. Short actual arguments that are variables remain
errors, but those that are expressions can be (again) extended on
the right with blanks.
Differential Revision: https://reviews.llvm.org/D125115
When we pass an alternate return specifier to a regular (not an asterisk)
dummy argument, flang would throw an internal compiler error of
derefencing a null pointer.
To avoid the ICE, a check was added.
Reviewed By: kiranchandramohan
Differential Revision: https://reviews.llvm.org/D123947
As Fortran 2018 C1533, a nonintrinsic elemental procedure shall not be
used as an actual argument. The semantic check for implicit iterface is
missed.
Reviewed By: klausler
Differential Revision: https://reviews.llvm.org/D124379
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().
f18 was emitting a warning about short character actual arguments to
subprograms and statement functions; every other compiler considers this
case to be an error.
Differential Revision: https://reviews.llvm.org/D123731
Error messages can have a list of attachments; these are used to point
to related source locations, supply additional information, and to
encapsulate error messages that were *not* emitted in a given context
to explain why a warning was justified.
This patch adds a message severity ("Because") for that last case,
and extends to AttachTo() API to provide a means for overriding
the severity of an attached message.
Some existing message attachments had their severities adjusted,
now that we're printing them. And operator==() for Message was
cleaned up while debugging after I noticed that it was recursively
O(N**2) and subject to returning a false positive.
Differential Revision: https://reviews.llvm.org/D123710
The actual argument shall have deferred the same type parameters as
the dummy argument if the argument is allocatable or pointer variable.
Currently programs not following this get one crash during execution.
Reviewed By: Jean Perier
Differential Revision: https://reviews.llvm.org/D122779
Previously, some semantic checks that are checking if an entity is an
allocatable were relying on the expression being a designator whose
last symbol has the allocatable attribute.
This is wrong since this was considering substrings and array sections of
allocatables as being allocatable. This is wrong (see NOTE 2 in
Fortran 2018 section 9.5.3.1).
Add evaluate::IsAllocatableDesignator to correctly test this.
Also add some semantic tests for ALLOCATED to test the newly added helper.
Note that ifort and nag are rejecting coindexed-named-object in
ALLOCATED (`allocated(coarray_scalar_alloc[2])`).
I think it is wrong given allocated argument is intent(in) as per
16.2.1 point 3.
So 15.5.2.6 point 4 regarding allocatable dummy is not violated (If the actual
argument is a coindexed object, the dummy argument shall have the INTENT (IN)
attribute.) and I think this is valid. gfortran accepts it.
The need for this helper was exposed in https://reviews.llvm.org/D122779.
Differential Revision: https://reviews.llvm.org/D122899
Co-authored-by: Peixin-Qiao <qiaopeixin@huawei.com>
