A recent change that corrected the name resolution of a generic interface
when the same name was visible in scope incorrectly prevented a local
generic from shadowing an outer name that is not a generic, subprogram,
or derived type -- e.g., a simple variable -- leading to an inappropriate
error message.
Differential Revision: https://reviews.llvm.org/D124276
The following code causes the compiler to ICE in several places due to
lack of support of recursive procedure definitions through the function
result.
function foo() result(r)
procedure(foo), pointer :: r
end function foo
A missing "!" in the call interface lowering caused all derived type
arguments without length parameters that require and explicit interface
to be passed via fir.box (runtime descriptor).
This was not the intent: there is no point passing a simple derived type
scalars or explicit shapes by descriptor just because they have an attribute
like TARGET. This would actually be problematic with existing code that is
not always 100% compliant: some code implicitly calls procedures with
TARGET dummy attributes (this is not something a compiler can enforce
if the call and procedure definition are not in the same file).
Add a Scope::IsDerivedTypeWithLengthParameter to avoid passing derived
types with only kind parameters by descriptor. There is no point, the
callee knows about the kind parameter values.
Differential Revision: https://reviews.llvm.org/D123990
When resolving a procedure reference, do not allow a successful
intrinsic procedure probe result to override an existing
symbol.
Differential Revision: https://reviews.llvm.org/D123905
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().
The x%KIND inquiry needs to be supported when 'x' is itself
a complex part reference or a type parameter inquiry.
Differential Revision: https://reviews.llvm.org/D123733
A POINTER attribute statement is allowed to add the POINTER attribute
to a procedure entity that has already been declared, e.g. with an
INTERFACE block.
Differential Revision: https://reviews.llvm.org/D123732
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
For parameterized derived type component initializers whose
expressions' types depend on parameter values, f18's current
scheme of analyzing the initialization expression once during
name resolution fails. For example,
type :: pdt(k)
integer, kind :: k
real :: component = real(0.0, kind=k)
end type
To handle such cases, it is necessary to re-analyze the parse
trees of these initialization expressions once for each distinct
initialization of the type.
This patch adds code to wipe an expression parse tree of its
typed expressions, and update those of its symbol table pointers
that reference type parameters, and then re-analyze that parse
tree to generate the properly typed component initializers.
Differential Revision: https://reviews.llvm.org/D123728
Prior to this patch, the semantics utility GetExpr() will crash
unconditionally if it encounters a typed expression in the parse
tree that has not been set by expression semantics. This is the
right behavior when called from lowering, by which time it is known
that the program had no fatal user errors, since it signifies a
fatal internal error. However, prior to lowering, in the statement
semantics checking code, a more nuanced test should be used before
crashing -- specifically, we should not crash in the face of a
missing typed expression when in error recovery mode.
Getting this right requires GetExpr() and its helper class to have
access to the semantics context, so that it can check AnyFatalErrors()
before crashing. So this patch touches nearly all of its call sites.
Differential Revision: https://reviews.llvm.org/D123873
Items in NAMELIST groups might be host-associated implicitly-typed
variables, but name resolution can't know that when the NAMELIST
appears in a specification part and the host's execution part has
not yet been analyzed. So defer NAMELIST group item name resolution
to the end of the execution part. This is safe because nothing
else in name resolution depends on whether a variable is in a
NAMELIST group or not.
Differential Revision: https://reviews.llvm.org/D123723
Construct entities from ASSOCIATE, SELECT TYPE, and SELECT RANK
are modifiable if the are associated with modifiable variables
without vector subscripts. Update WhyNotModifiable() to accept
construct entities that are appropriate.
A need for more general error reporting from one overload of
WhyNotModifiable() caused its result type to change to
std::optional<parser::Message> instead of ::MessageFixedText,
and this change had some consequences that rippled through
call sites.
Some test results that didn't allow for modifiable construct
entities needed to be updated.
Differential Revision: https://reviews.llvm.org/D123722
TYPE IS and CLASS IS guards in SELECT TYPE constructs are
allowed to specify the same type as the type of the selector
but f18's implementation of that predicate required strict
equality of the derived type representations. We need to
allow for assumed values of LEN type parameters to match
explicit and deferred type parameter values in the selector
and require equality for KIND type parameters. Implement
DerivedTypeSpec::Match() to perform this more relaxed type
comparison, and use it in check-select-type.cpp.
Differential Revision: https://reviews.llvm.org/D123721
It is possible for generic interfaces of equivalent (but not necessarily
identical -- operator(.eq.) is equivalent to operator(==)) names to
be declared in a host scope and a nested scope, and the nested declaration
should function as an extension of the host's.
Differential Revision: https://reviews.llvm.org/D123719
A generic interface (however spelled) can have the same name as
an intrinsic procedure in the same scope. When an explicit INTRINSIC
attribute statement appears in a nested scope, semantics was
unconditionally declaring a new symbol that hid the generic entirely.
Catch this case and create instead a host association symbol for
the generic that can then be decorated with the INTRINSIC attribute.
Differential Revision: https://reviews.llvm.org/D123718
Fortran allows a generic interface to have he same name as an
intrinsic procedure. If the intrinsic is explicitly marked with
the INTRINSIC attribute, restrictions apply (C848) - the generic
must contain only functions or subroutines, depending on the
intrinsic. Explicit or not, the generic overrides the intrinsic,
but the intrinsic behavior must still be available for calls
whose actual arguments do not match any of the specific procedures.
Semantics was not checking constraint C848, and it didn't allow
an explicit INTRINSIC attribute on a name of a generic interface.
Differential Revision: https://reviews.llvm.org/D123713
When a type specification appears in the prefix of a FUNCTION statement,
defer its processing as late as possible so that any symbols in the
tpe specification can be resolved in the function's scope to local
declarations, including use-associated symbols. f18 was already doing
this deferral in a limited form for derived types, and this patch
makes it work for intrinsic type parameter values as well.
In short, "real(kind(x)) function foo(x)" now works as it should.
"As late as possible" means the end of the specification part, or
the first appearance of the function result name in the specification
part.
Differential Revision: https://reviews.llvm.org/D123705
Fortran admits a few ways to have multiple symbols with the
same name in the same scope. Two of them involve generic
interfaces (from INTERFACE or GENERIC, the syntax doesn't matter);
these are allowed to inhabit a scope with either a derived type or
a subprogram that is also a specific procedure of the generic.
(But not both a derived type and a subprogram; they could not
cohabit a scope anyway, generic or not.)
In cases of USE association, f18 needs to be capable of combining
use-associated generic interfaces with other use-associated entities.
Two generics get merged (this case was nearly correct); a generic
and a derived type can merge into a GenericDetails with a shadowed
derivedType(); and a generic can replace or ignore a use-associated
procedure of the same name so long as that procedure is already
one of its specifics.
Further, these modifications to the use-associated generic
interface must be made to a local copy of the symbol. The previous
code was messing directly with the symbol in the module's scope.
The fix is basically a reimplementation of the member function
DoAddUse() in name resolution.
Differential Revision: https://reviews.llvm.org/D123704
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
Catch and nicely describe errors in CASE range values
that are out of range for the type of the SELECT CASE.
Differential Revision: https://reviews.llvm.org/D123708
When padding is required in a COMMON block to ensure alignment
of a component, emit a portability warning.
Differential Revision: https://reviews.llvm.org/D123706
This patch supports the following checks for ORDERED construct:
```
[5.1] 2.19.9 ORDERED Construct
The worksharing-loop or worksharing-loop SIMD region to which an ordered
region corresponding to an ordered construct without a depend clause
binds must have an ordered clause without the parameter specified on the
corresponding worksharing-loop or worksharing-loop SIMD directive.
The worksharing-loop region to which an ordered region that corresponds
to an ordered construct with any depend clauses binds must have an
ordered clause with the parameter specified on the corresponding
worksharing-loop directive.
An ordered construct with the depend clause specified must be closely
nested inside a worksharing-loop (or parallel worksharing-loop)
construct.
An ordered region that corresponds to an ordered construct with the simd
clause specified must be closely nested inside a simd or
worksharing-loop SIMD region.
```
Reviewed By: kiranchandramohan, shraiysh, NimishMishra
Differential Revision: https://reviews.llvm.org/D113399
The information about OpenMP/OpenACC declarative directives in modules
should be carried in export mod files. This supports export OpenMP
Threadprivate directive and import OpenMP declarative directives.
Reviewed By: kiranchandramohan
Differential Revision: https://reviews.llvm.org/D120396
As Fortran 2018 3.18 states, the branch target statement can be
`forall-construct-stmt`, but cannot be `forall-stmt`. `forall-stmt` is
wrapped by `Statement` in `action-stmt` and `action-stmt` can be one
branch target statement. Fix the semantic analysis and add two
regression test cases in lowering.
Reviewed By: Jean Perier
Differential Revision: https://reviews.llvm.org/D123373
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
In case a character component PDT length only depends on kind parameters,
fold it while instantiating the PDT. This is especially important if the
component has an initializer because later semantic phases (offset
computation or runtime type info generation) might get confused and
generate offset/type info that will lead to crashes in lowering.
Differential Revision: https://reviews.llvm.org/D122938
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>
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
Assignment semantics was coughing up bad errors and crashes for
intrinsic assignments to unlimited polymorphic entities while
looking for any (impossible) user defined ASSIGNMENT(=) generic
or intrinsic type conversion.
Differential Revision: https://reviews.llvm.org/D122440
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
Similarly to LBOUND in https://reviews.llvm.org/D121488, UBOUND must
return zero for an empty dimension, no matter the specification
expression.
Add a GetUBOUND method to be used in expression rewrite that prevents
folding UBOUND to a bound specification expression if the extent is
not a compile time constant.
Fold the case where the extents is known to be zero (and also deal with
this case in LBOUND since we can and should to comply with constant
expression requirements).
Differential Revision: https://reviews.llvm.org/D122242
Name resolution was crashing while processing the ENTRY statement
due to a lack of special-case code necessary to handle the indirection
needed when the generic has the same name as the ENTRY.
Differential Revision: https://reviews.llvm.org/D122050
This patch adds translation from PFT to FIR for critical construct.
This is part of the upstreaming effort from the fir-dev branch in [1].
[1] https://github.com/flang-compiler/f18-llvm-project
Co-authored-by: kiranchandramohan <kiranchandramohan@gmail.com>
Reviewed By: kiranchandramohan
Differential Revision: https://reviews.llvm.org/D122218
This patch adds parser nodes for each indivudual section in sections
construct. This should help with the translation to FIR. `!$omp section`
was not recognized as a construct and hence needed special handling.
`OpenMPSectionsConstruct` contains a list of `OpenMPConstruct`. Each
such `OpenMPConstruct` wraps an `OpenMPSectionConstruct`
(section, not sections). An `OpenMPSectionConstruct` is a wrapper around
a `Block`.
Reviewed By: kiranchandramohan, peixin
Differential Revision: https://reviews.llvm.org/D121680
Interfaces which are internal to a procedure need to be included in
module files if (and only if) they are referenced in the interface of
the procedure. That is, they are needed if they are the interfaces of
dummy or return value procedures.
Fixes#53420
Differential Revision: https://reviews.llvm.org/D121738
The intrinsic module IEEE_ARITHMETIC must incorporate the public
names from the intrisic module IEEE_EXCEPTIONS. Rename IEEE_EXCEPTIONS
to __Fortran_ieee_exceptions so that it won't clash with the
nonintrinsic namespace, establish a new intrinic IEEE_EXCEPTIONS
module that USEs it, and add a USE to IEEE_ARITHMETIC.
Updated to use STREQUAL rather than ambiguous MATCHES in
the CMakeLists.txt file.
Differential Revision: https://reviews.llvm.org/D121490
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
The intrinsic module IEEE_ARITHMETIC must incorporate the public
names from the intrisic module IEEE_EXCEPTIONS. Rename IEEE_EXCEPTIONS
to __Fortran_ieee_exceptions so that it won't clash with the
nonintrinsic namespace, establish a new intrinic IEEE_EXCEPTIONS
module that USEs it, and add a USE to IEEE_ARITHMETIC.
Differential Revision: https://reviews.llvm.org/D121490
evaluate::IsPointerObject used to return true for pointer suboject like
`pointer(10)` while these object are not pointers. This prevented some
checks like 15.5.2.7 to be correctly enforced (e.g., it was possible to
pass `pointer(10)` to a non intent(in) dummy pointer).
After updating IsPointerObject behavior and adding a test for 15.5.2.7 in
call07.f90, a test in call03.f90 for 15.5.2.4(14) was failing.
It appeared the related semantics check was relying on IsPointerObject
to return true for `pointer(10)`. Adapt the code to detect pointer element
in another way.
While looking at the code, I also noticed that semantics was
rejecting `character(1)` pointer/assumed shape suboject when these are
allowed (the standard has a special case for character(1) in
15.5.2.4(14), and I verified that other compilers that enforce 15.5.2.4(14)
do accept this).
Differential Revision: https://reviews.llvm.org/D121377
Using recently established message severity codes, upgrade
non-fatal messages to usage and portability warnings as
appropriate.
Differential Revision: https://reviews.llvm.org/D121246
F18 presently has fatal and non-fatal diagnostic messages. We'd like
to make non-fatal warnings stand out better in the output of the compiler.
This will turn out to be a large change that affects many files.
This patch is just the first part. It converts a Boolean isFatal_ data
member of the message classes into a severity code, and defines four
of these codes (Error, Warning, Portability, and a catch-all Other).
Later patches will result from sweeping over the parser and semantics,
changing most non-fatal diagnostic messages into warnings and portability
notes.
Differential Revision: https://reviews.llvm.org/D121228
When a module uses a derived type that is shadowed by a generic
interface, the module file was missing a USE statement for the
name. Detect and handle this situation.
Differential Revision: https://reviews.llvm.org/D121160
When a structure constructor does not initialize an allocatable component,
ensure that the typed expression representation contains an explicit
NULL() for the component. Expression semantics already copies default
initialized expressions for nonallocatable components into structure
constructors. This change is expected to simplify lowering.
Differential Revision: https://reviews.llvm.org/D121162
Peter Klausler