Save both the raw procedure interface symbol as well as the result of
passing it through GetUltimate() and BypassGeneric() in symbol table
entries with ProcEntityDetails. The raw symbol of the interface needs to
be the one used for emitting procedure symbols to module files.
Fixes https://github.com/llvm/llvm-project/issues/83836.
…edures
Fortran allows a generic interface to have the same name as a derived
type in the same scope. It also allows a generic interface to have the
same name as one of its specific procedures.
When two modules define the same name, possibly more than once each,
things get exciting. The standard is not clear, and other compilers do
variously different things. We are currently emitting some errors
prematurely for some usage in pfUnit due to how it combines two versions
of a package together via USE association.
This patch handles combinations of derived types and generic interfaces
and their specific procedures in a more principled way. Errors due to
ambiguity are deferred to actual usage of derived types and specific
procedures -- and when they're not used, the program is unambiguous and
no error issues.
The runtime skips finalization if the runtime type info
"nofinalizationneeded" is set, so it should not be set if the derived
type has polymorphic allocatable components since they may be allocated
to some type extension with a final methods.
IsFinalizable cannot be updated since polymorphic allocatable components
do not imply a final routine will actually be called (it depends of the
dynamic type, which semantics cannot know about), and this would not
match the "Finalizable" definition of the standard in 7.5.6.1. Hence,
this patch adds a MayRequireFinalization helper.
The component visitor change is to avoid crashing in
FindPolymorphicAllocatableUltimateComponent in the test
test/Driver/dump-all-bad.f90 that tries generating runtime type info
even after some semantic error is raised under debug-dump options.
This patch changes how common blocks are aggregated and named in
lowering in order to:
* fix one obvious issue where BIND(C) and non BIND(C) with the same
Fortran name were "merged"
* go further and deal with a derivative where the BIND(C) C name matches
the assembly name of a Fortran common block. This is a bit unspecified
IMHO, but gfortran, ifort, and nvfortran "merge" the common block
without complaints as a linker would have done. This required getting
rid of all the common block mangling early in FIR (\_QC) instead of
leaving that to the phase that emits LLVM from FIR because BIND(C)
common blocks did not have mangled names. Care has to be taken to deal
with the underscoring option of flang-new.
See added flang/test/Lower/HLFIR/common-block-bindc-conflicts.f90 for an
illustration.
Unlike other executable constructs with associating selectors, the
selector of a SELECT RANK construct can have the ALLOCATABLE or POINTER
attribute, and will work as an allocatable or object pointer within
each rank case, so long as there is no RANK(*) case.
Getting this right exposed a correctness risk with the popular
predicate IsAllocatableOrPointer() -- it will be true for procedure
pointers as well as object pointers, and in many contexts, a procedure
pointer should not be acceptable. So this patch adds the new predicate
IsAllocatableOrObjectPointer(), and updates some call sites of the original
function to use the new one.
Differential Revision: https://reviews.llvm.org/D159043
When checking that a module procedure definition is unique, allow for
the possibility that a submodule may contain a module procedure
interface that shadows a module procedure of the same name in its
(sub)module parent. In other words, module procedure definitions
need only be unique in the tree of submodules rooted at the (sub)module
containing the relevant module procedure interface.
Differential Revision: https://reviews.llvm.org/D159033
The statement "A(J) = expr" could be an assignment to an element of an
array A, an assignment to the target of a pointer-valued function A, or
the definition of a new statement function in the local scope named A,
depending on whether it appears in (what might still be) the specification
part of a program or subprogram and what other declarations and definitions
for A might exist in the local scope or have been imported into it.
The standard requires that the name of a statement function appear in
an earlier type declaration statement if it is also the name of an
entity in the enclosing scope. Some other Fortran compilers mistakenly
enforce that rule in the case of an assignment to the target of a
pointer-valued function in the containing scope, after misinterpreting
the assignment as a new local statement function definition.
This patch cleans up the handling of the various possibilities and
resolves what was a crash in the case of a statement function definition
whose name was the same as that of a procedure in the outer scope whose
result is *not* a pointer.
Differential Revision: https://reviews.llvm.org/D155493
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
Add representations of CUDA Fortran data and subprogram attributes
to the symbol table and scopes of semantics. Set them in name
resolution, and emit them to module files.
Depends on https://reviews.llvm.org/D150159.
Differential Revision: https://reviews.llvm.org/D150161
Begin upstreaming of CUDA Fortran support in LLVM Flang.
This first patch implements parsing for CUDA Fortran syntax,
including:
- a new LanguageFeature enum value for CUDA Fortran
- driver change to enable that feature for *.cuf and *.CUF source files
- parse tree representation of CUDA Fortran syntax
- dumping and unparsing of the parse tree
- the actual parsers for CUDA Fortran syntax
- prescanning support for !@CUF and !$CUF
- basic sanity testing via unparsing and parse tree dumps
... along with any minimized changes elsewhere to make these
work, mostly no-op cases in common::visitors instances in
semantics and lowering to allow them to compile in the face
of new types in variant<> instances in the parse tree.
Because CUDA Fortran allows the kernel launch chevron syntax
("call foo<<<blocks, threads>>>()") only on CALL statements and
not on function references, the parse tree nodes for CallStmt,
FunctionReference, and their shared Call were rearranged a bit;
this caused a fair amount of one-line changes in many files.
More patches will follow that implement CUDA Fortran in the symbol
table and name resolution, and then semantic checking.
Differential Revision: https://reviews.llvm.org/D150159
Fortran doesn't allow inaccessible procedure bindings to be
overridden, and this needs to apply to generic resolution.
When resolving a type-bound generic procedure from another
module, ensure only that the most extended override from its
module is used if it is PRIVATE, not a later apparent override
from another module.
Differential Revision: https://reviews.llvm.org/D150721
Pointer components without default initialization pose some
difficult (or impossible) problems when they appear as right-hand
side targets in pointer assignment statements; they may contain
garbage or stale data that looks enough like a valid descriptor
to cause a crash. Solve the problem by avoiding it -- ensure
that pointers' descriptors are at least minimally established.
Differential Revision: https://reviews.llvm.org/D149979
A fairly recent introduction of runtime I/O APIs called OutputDerivedType()
and InputDerivedType() didn't cover NAMELIST I/O's need to access
non-type-bound generic interfaces for user-defined derived type I/O
when those generic interfaces are defined in some scope other than the
one that defines the derived type.
The patch adds a new data structure shared between lowering
and the runtime that can represent all of the cases that can
arise with non-type-bound defined I/O. It can represent
scopes in which non-type-bound defined I/O generic interfaces
are inaccessible, too, due to IMPORT statements.
The data structure is now an operand to OutputDerivedType() and
InputDerivedType() as well as a data member in the NamelistGroup
structure.
Differential Revision: https://reviews.llvm.org/D148257
Many semantic checks for constraints related to PURE subprograms
can be implemented in terms of Semantics' "definable.h" utilities,
slightly expanded. Replace some particular PURE constraint
checks with calls to WhyNotDefinable(), except for cases that
had better specific error messages, and start checking some
missing constraints with DEALLOCATE statements and local
variable declarations.
Differential Revision: https://reviews.llvm.org/D147389
The utility routine in semantics that determines whether an
executable construct constitutes an image control statement
was not examining the single action statement controlled by
a non-construct IF statement, e.g. 'IF(P) STOP'.
Differential Revision: https://reviews.llvm.org/D146584
The present I/O infrastructure for user-defined derived type I/O
subroutines works fine for type-bound I/O generic bindings. It also works
for explicit INTERFACE blocks and GENERIC statements that define
UDDIO subroutines in the same scope as the definition of the derived type,
so long as the specific procedures in those bindings are module procedures
or external procedures.
For non-type-bound UDDTIO specific procedures that are dummy procedures,
thunks of inner procedures, or procedure pointers, or that are defined with
interfaces or GENERIC outside the scope of the definition of the derived
type, a new runtime I/O API is needed so that lowering can generate
a call that supplies the appropriate procedure as well as the defined
type instance.
This patch specifies and implements this new runtime API and provides
utility routines for lowering to use to determine whether it should be
called for any particular OutputItem or InputItem in the parse tree.
Differential Revision: https://reviews.llvm.org/D146571
Non-DEFERRED procedure binding checking can't blindly accept
all procedures defined in modules -- they can't be ABSTRACT
interfaces. And GetUltimate() must be used rather than
FindSubprogram(); the latter will resolve to a procedure's
interface in the case of "procedure(interface) :: external",
not "external".
Differential Revision: https://reviews.llvm.org/D145749
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
If the interface specifies BIND(C), then the declarations using
this interface inherit BIND(C), and if they are referenced via use
association they must be classified as BIND(C) subprograms.
Differential Revision: https://reviews.llvm.org/D145084
When a descriptor inquiry or inquiry function's result is
not constant and is known to be impossible to correctly determine
at runtime, raise an error. For example, LEN(X) when X is
a local allocatable variable with deferred length.
Differential Revision: https://reviews.llvm.org/D142759
This patch implements the derived-type finalization for
monomorphic and polymorphic derived-type.
The finalization is done through a call to the `Destroy`
runtime function so the allocatable component object are also
finalized correctly when needed. It would be possible to finalize
monomorphic derived-type with non finalizable component with a
direct call to their finalize subroutine.
7.5.6.3 point 1: LHS nonallocatable object and LHS allocatable
object finalization. Done with call to `Destroy` for monomorphic
derived-type and through `Assign` for polymorphic entities.
7.5.6.3 point 2: Done within the deallocation calls.
7.5.6.3 point 3: A function context is added to the bridge to
attach finalization that need to happen on function/subroutine
exit.
7.5.6.3 point 4: BLOCK construct not yet implemented.
7.5.6.3 point 5/6: Finalization attach to the stmtCtx in a
similar way than 9.7.3.2 point 4.
7.5.6.3 point 7: INTENT(OUT) finalization done with a
call to `Destroy` runtime function call.
This patch passes 9/10 tests in the proposed test-suite
https://github.com/llvm/llvm-test-suite/pull/13
- The case with BLOCK construct will be implemented later when
BLOCK are implemented upstream.
- Automatic deallocation is not yet implemented. Finalization triggered
by automatic deallocation is then not triggered.
Reviewed By: jeanPerier, PeteSteinfeld
Differential Revision: https://reviews.llvm.org/D142707
The ProcInterface structure is used only by ProcEntityDetails; it represents
what a program might have put in parentheses in a procedure-declaration-stmt,
either the name of a procedure interface or a declaration-type-spec.
If a procedure entity has an implicit interface, the function result
type (if any) can be kept in EntityDetails::type_, which already exists
and is currently redundant for ProcEntityDetails symbols.
All that is really needed is a nullable Symbol pointer in ProcEntityDetails
to point to the procedure's explicit interface, when it has one.
Also, catch the case where a procedure has an explicit interface
and a program attempts to also give it a type.
Differential Revision: https://reviews.llvm.org/D140134
In a pure context, a pointer acquired from an INTENT(IN) dummy argument
may not be copied. Catch the case in which the pointer is a component
of an allocatable component at some depth of nesting.
(This patch adds a new component iterator kind that is a variant of
a potential subobject component iterator; it visits all potential
subobject components, plus pointers, into which it does not descend.)
Differential Revision: https://reviews.llvm.org/D139161
Type-bound generics like operator(+) and assignment(=) need to not be
PRIVATE if they are used outside the module in which they are declared.
Differential Revision: https://reviews.llvm.org/D139123
12.6.3p5 requires an I/O data list item to have a defined I/O procedure
if it is polymorphic. (We could defer this checking to the runtime,
but no other Fortran compiler does so, and we would also have to be
able to catch the case of an allocatable or pointer direct component
in the absence of a defined I/O subroutine.)
Also includes a patch to name resolution that ensures that a
SELECT TYPE construct entity is polymorphic in the domain of a
CLASS IS guard.
Also ensures that non-defined I/O of types with PRIVATE components
is caught.
Differential Revision: https://reviews.llvm.org/D139050
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
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
Procedure bindings with explicit interfaces don't work when the
interface is shadowed by a generic interface of the same name,
and can produce spurious semantic error messages. Extend the
characterization and checking code for such things, and the utility
functionns on which they depend, to dig through generics when they
occlude interface-defining subprograms. This is done on demand in
checking code, not once during name resolution, because the
procedures in question may also be forward-referenced.
Differential Revision: https://reviews.llvm.org/D131105
diff --git a/flang/include/flang/Semantics/symbol.h b/flang/include/flang/Semantics/symbol.h
index e79f8ab6503e..0b03bf06eb73 100644
--- a/flang/include/flang/Semantics/symbol.h
We need to distinguish BLOCK host association from subprogram host
association when checking assignments in PURE subprograms.
The specific case that is not allowed is an assignment to a variable
from the scope around the PURE subprogram.
Differential Revision: https://reviews.llvm.org/D131098
The predicate IsHostAssocited() was implemented in a way that would
return true only for cases of host association into a module or inner
subprogram. Technically, the use of a name in a BLOCK construct
that is not declared therein is considered in the Fortran standard
to also be a form of host association, and this matters when doing
error checking on DATA statements.
Differential Revision: https://reviews.llvm.org/D130388
If BIND(C) appears on an internal procedure, it must have a null binding
label, i.e. BIND(C,NAME="").
Also address conflicts with D127725 which was merged during development.
Differential Revision: https://reviews.llvm.org/D128676
The predicate that determines image control statements needs
to distinguish STOP (which is) from ERROR STOP (which isn't).
Differential Revision: https://reviews.llvm.org/D127796
When two or more generic interfaces are available by declaration or
by USE association at different scoping levels, we need to search
the outer generic interfaces as well as the inner ones, but only after
the inner ones have failed to produce a specific procedure that matches
a given set of actual arguments. This means that it is possible for
a specific procedure of a generic interface of an inner scope to override
a conflicting specific procedure of a generic interface of an outer
scope.
Also cope with forward references to derived types when a generic
interface is also in scope.
Fixes LLVM bug https://github.com/llvm/llvm-project/issues/55240 and
LLVM bug https://github.com/llvm/llvm-project/issues/55300.
Differential Revision: https://reviews.llvm.org/D126587
A utility predicate in semantics was incorrectly determining that
an INTERFACE ASSIGNMENT(=) (or other form of generic) could not have
a specific procedure with an unlimited polymorphic second argument.
This led to a crash later in expression analysis. Fix, and
extend tests.
Differential Revision: https://reviews.llvm.org/D126151
Forward references to ENTRY names to pass them as actual procedure arguments
don't work in all cases, exposing some basic ordering problems in
name resolution for these symbols. Refactor; create all the
necessary procedure symbols, and either function result or host association
symbols (for subroutines), at the time that the subprogrma scope is
created, so that the names exist in the scope as text "before"
the ENTRY is processed in name resolution. Some processing
remains in PostEntryStmt() so that we can check that an ENTRY with
an explicit distinct RESULT doesn't also have declarations for the
ENTRY name.
Differential Revision: https://reviews.llvm.org/D126142
As is already supported for dummy procedures, we need to also accept
declarations of procedure pointers that consist of a POINTER attribute
statement followed by an INTERFACE block. (The case of an INTERFACE
block followed by a POINTER statement already works.)
While cleaning this case up, adjust the utility predicate IsProcedurePointer()
to recognize it (namely a SubprogramDetails symbol with Attr::POINTER)
and delete IsProcName(). Extend tests, and add better comments to
symbol.h to document the two ways in which procedure pointers are
represented.
Differential Revision: https://reviews.llvm.org/D125139
The semantic test for an intrinsic assignment to a polymorphic
derived type entity from a type that is an extension of its base
type was reversed, so it would allow assignments that it shouldn't
and disallowed some that it should; and the test case for it
incorectly assumed that the invalid semantics were correct.
Fix the code and the test, and add a new test for the invalid
case (LHS type is an extension of the RHS type).
Differential Revision: https://reviews.llvm.org/D125135
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().
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
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
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
