For the program provided as the test case flang fired the following
error:
error: Semantic errors in main.f90
error: 'foo' is not a procedure
This change fixes the error by postponing handling of `UseErrorDetails`
from `CharacterizeProcedure` to a later stage.
Reviewed By: kiranchandramohan
Differential Revision: https://reviews.llvm.org/D125791
Functions returning ALLOCATABLE or POINTER arrays have descriptor inquiries in
their results' shape expressions that won't compare equal. These functions
need only be checked for compatible ranks (& of course other characteristics).
Differential Revision: https://reviews.llvm.org/D125123
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
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().
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
The "seenProcs" sets passed as arguments to the procedure and dummy
procedure characterization routines need to be passed by value so that
local updates to those sets do not become permanent. They are
presently passed by reference and that has led to bogus errors about
recursively defined procedures in testing.
(It might be faster to pass the sets by reference and undo those local
updates in these functions, but that's error-prone, and the performance
difference is not expected to be detectable in practice.)
Differential Revision: https://reviews.llvm.org/D122439
Add new IsCompatibleWith() member functions to many classes in evaluate::characteristics
that apply more nuanced compatibility checking for function results, dummy
arguments, and procedure interfaces than the previous tests for complete
equivalence. Use IsCompatibleWith() in semantics for call checking.
Differential Revision: https://reviews.llvm.org/D120844
When a pointer assignment with bounds remapping has a function
reference as its right-hand side, don't check for array conformance.
Differential Revision: https://reviews.llvm.org/D119845
ENTRY point symbols aren't marked PURE in the symbol table, but must
instead inherit the attribute from their containing subprograms.
There's a predicate in semantics that does this, but it wasn't being
used in the context of actual procedure argument characterization.
Differential Revision: https://reviews.llvm.org/D119564
Some kinds of Fortran arrays are declared with the same syntax,
and it is impossible to tell from a shape (:, :) or (*) whether
the object is assumed shape, deferred shape, assumed size, implied
shape, or whatever without recourse to more information about the
symbol in question. This patch softens the names of some predicate
functions (IsAssumedShape to CanBeAssumedShape) and makes others
more reflective of the syntax they represent (isAssumed to isStar)
in an attempt to encourage coders to seek and find definitive
predicate functions whose names deliver what they seem to mean.
Address TODO comments in IsSimplyContiguous() by using the
updated IsAssumedShape() predicate.
Differential Revision: https://reviews.llvm.org/D114829
Section 10.2.2.4, paragraph 3 states that, for procedure pointer assignment:
If the pointer object has an explicit interface, its characteristics shall be
the same as the pointer target ...
Thus, it's illegal for a procedure pointer with an explicit interface to be
associated with a procedure whose interface is implicit. However, there's no
prohibition that disallows a procedure pointer with an implicit interface from
being associated with a procedure whose interface is explicit.
We were incorrectly emitting an error message for this latter case.
We were also not covering the case of procedures with explicit
interfaces where calling them requires the use of a descriptor. Such
procedures cannot be associated with procedure pointers with implicit
interfaces.
Differential Revision: https://reviews.llvm.org/D113706
Check that when a procedure pointer is initialised or assigned with an intrinsic
function, or when its interface is being defined by one, that intrinsic function
is unrestricted specific (listed in Table 16.2 of F'2018).
Mark intrinsics LGE, LGT, LLE, and LLT as restricted specific. Getting their
classifications right helps in designing the tests.
Differential Revision: https://reviews.llvm.org/D112381
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
When a function is called in a specification expression, it must be
sufficiently defined, and cannot be a recursive call (10.1.11(5)).
The best fix for this is to change the contract for the procedure
characterization infrastructure to catch and report such errors,
and to guarantee that it does emit errors on failed characterizations.
Some call sites were adjusted to avoid cascades.
Differential Revision: https://reviews.llvm.org/D104330
To ensure that errors are emitted by CheckConformance and
its callers in all situations, it's necessary for the returned result
of that function to distinguish between three possible
outcomes: the arrays are known to conform at compilation time,
the arrays are known to not conform (and a message has been
produced), and an indeterminate result in which is not possible
to determine conformance. So convert CheckConformance's
result into an optional<bool>, and convert its confusing
Boolean flag arguments into a bit-set of named flags too.
Differential Revision: https://reviews.llvm.org/D103654
Add some missing error messages, and permit the appearance
of EntityDetails symbols in dummy argument type characterization.
Differential Revision: https://reviews.llvm.org/D103576
The constexpr-capable class evaluate::DynamicType represented
CHARACTER length only with a nullable pointer into the declared
parameters of types in the symbol table, which works fine for
anything with a declaration but turns out to not suffice to
describe the results of the ACHAR() and CHAR() intrinsic
functions. So extend DynamicType to also accommodate known
constant CHARACTER lengths, too; use them for ACHAR & CHAR;
clean up several use sites and fix regressions found in test.
Differential Revision: https://reviews.llvm.org/D103571
A procedure pointer is allowed to name a specific intrinsic function
from F'2018 table 16.2 as its interface, but not other intrinsic
procedures. Catch this error, and thereby also fix a crash resulting
from a failure later in compilation from failed characteristics;
while here, also catch the similar error with initializers.
Differential Revision: https://reviews.llvm.org/D103570
Defined input/output procedures are specified in 12.6.4.8. There are different
versions for read versus write and formatted versus unformatted, but they all
share the same basic set of dummy arguments.
I added several checking functions to check-declarations.cpp along with a test.
In the process of implementing this, I noticed and fixed a typo in
.../lib/Evaluate/characteristics.cpp.
Differential Revision: https://reviews.llvm.org/D103045
Replace semantics::SymbolSet with alternatives that clarify
whether the set should order its contents by source position
or not. This matters because positionally-ordered sets must
not be used for Symbols that might be subjected to name
replacement during name resolution, and address-ordered
sets must not be used (without sorting) in circumstances
where the order of their contents affects the output of the
compiler.
All set<> and map<> instances in the compiler that are keyed
by Symbols now have explicit Compare types in their template
instantiations. Symbol::operator< is no more.
Differential Revision: https://reviews.llvm.org/D98878
It's possible to define a procedure whose interface depends on a procedure
which has an interface that depends on the original procedure. Such a circular
definition was causing the compiler to fall into an infinite loop when
resolving the name of the second procedure. It's also possible to create
circular dependency chains of more than two procedures.
I fixed this by adding the function HasCycle() to the class DeclarationVisitor
and calling it from DeclareProcEntity() to detect procedures with such
circularly defined interfaces. I marked the associated symbols of such
procedures by calling SetError() on them. When processing subsequent
procedures, I called HasError() before attempting to analyze their interfaces.
Unfortunately, this did not work.
With help from Tim, we determined that the SymbolSet used to track the
erroneous symbols was instantiated using a "<" operator which was defined using
the location of the name of the procedure. But the location of the procedure
name was being changed by a call to ReplaceName() between the times that the
calls to SetError() and HasError() were made. This caused HasError() to
incorrectly report that a symbol was not in the set of erroneous symbols.
I fixed this by changing SymbolSet to be an unordered set that uses the
contents of the name of the symbol as the basis for its hash function. This
works because the contents of the name of the symbol is preserved by
ReplaceName() even though its location changes.
I also fixed the error message used when reporting recursively defined
dummy procedure arguments by removing extra apostrophes and sorting the
list of symbols.
I also added tests that will crash the compiler without this change.
Note that the "<" operator is used in other contexts, for example, in the map
of characterized procedures, maps of items in equivalence sets, maps of
structure constructor values, ... All of these situations happen after name
resolution has been completed and all calls to ReplaceName() have already
happened and thus are not subject to the problem I ran into when ReplaceName()
was called when processing procedure entities.
Note also that the implementation of the "<" operator uses the relative
location in the cooked character stream as the basis of its implementation.
This is potentially problematic when symbols from diffent compilation units
(for example symbols originating in .mod files) are put into the same map since
their names will appear in two different source streams which may not be
allocated in the same relative positions in memory. But I was unable to create
a test that caused a problem. Using a direct comparison of the content of the
name of the symbol in the "<" operator has problems. Symbols in enclosing or
parallel scopes can have the same name. Also using the location of the symbol
in the cooked character stream has the advantage that it preserves the the
order of the symbols in a structure constructor constant, which makes matching
the values with the symbols relatively easy.
This patch supersedes D97749.
Differential Revision: https://reviews.llvm.org/D97774
It's possible to define a procedure whose interface depends on a procedure
which has an interface that depends on the original procedure. Such a circular
definition was causing the compiler to fall into an infinite loop when
resolving the name of the second procedure. It's also possible to create
circular dependency chains of more than two procedures.
I fixed this by adding the function HasCycle() to the class DeclarationVisitor
and calling it from DeclareProcEntity() to detect procedures with such
circularly defined interfaces. I marked the associated symbols of such
procedures by calling SetError() on them. When processing subsequent
procedures, I called HasError() before attempting to analyze their interfaces.
Unfortunately, this did not work.
With help from Tim, we determined that the SymbolSet used to track the
erroneous symbols was instantiated using a "<" operator which was defined using
the location of the name of the procedure. But the location of the procedure
name was being changed by a call to ReplaceName() between the times that the
calls to SetError() and HasError() were made. This caused HasError() to
incorrectly report that a symbol was not in the set of erroneous symbols.
I fixed this by changing SymbolSet to be an unordered set that uses the
contents of the name of the symbol as the basis for its hash function. This
works because the contents of the name of the symbol is preserved by
ReplaceName() even though its location changes.
I also fixed the error message used when reporting recursively defined dummy
procedure arguments.
I also added tests that will crash the compiler without this change.
Note that the "<" operator is used in other contexts, for example, in the map
of characterized procedures, maps of items in equivalence sets, maps of
structure constructor values, ... All of these situations happen after name
resolution has been completed and all calls to ReplaceName() have already
happened and thus are not subject to the problem I ran into when ReplaceName()
was called when processing procedure entities.
Note also that the implementation of the "<" operator uses the relative
location in the cooked character stream as the basis of its implementation.
This is potentially problematic when symbols from diffent compilation units
(for example symbols originating in .mod files) are put into the same map since
their names will appear in two different source streams which may not be
allocated in the same relative positions in memory. But I was unable to create
a test that caused a problem. Using a direct comparison of the content of the
name of the symbol in the "<" operator has problems. Symbols in enclosing or
parallel scopes can have the same name. Also using the location of the symbol
in the cooked character stream has the advantage that it preserves the the
order of the symbols in a structure constructor constant, which makes matching
the values with the symbols relatively easy.
This change supersedes D97201.
Differential Revision: https://reviews.llvm.org/D97749
This reverts commit 07de0846a5.
The original patch has caused 6 out 8 of Flang's public buildbots to
fail. As I'm not sure what the fix should be, I'm reverting this for
now. Please see https://reviews.llvm.org/D97201 for more context and
discussion.
It's possible to define a procedure whose interface depends on a procedure
which has an interface that depends on the original procedure. Such a circular
definition was causing the compiler to fall into an infinite loop when
resolving the name of the second procedure. It's also possible to create
circular dependency chains of more than two procedures.
I fixed this by adding the function HasCycle() to the class DeclarationVisitor
and calling it from DeclareProcEntity() to detect procedures with such
circularly defined interfaces. I marked the associated symbols of such
procedures by calling SetError() on them. When processing subsequent
procedures, I called HasError() before attempting to analyze their interfaces.
Unfortunately, this did not work.
With help from Tim, we determined that the SymbolSet used to track the
erroneous symbols was instantiated using a "<" operator which was
defined using the name of the procedure. But the procedure name was
being changed by a call to ReplaceName() between the times that the
calls to SetError() and HasError() were made. This caused HasError() to
incorrectly report that a symbol was not in the set of erroneous
symbols. I fixed this by making SymbolSet be an ordered set, which does
not use the "<" operator.
I also added tests that will crash the compiler without this change.
And I fixed the formatting on an error message from a previous update.
Differential Revision: https://reviews.llvm.org/D97201
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
It's possible to define a procedure that has a procedure dummy argument which
names the procedure that contains it. This was causing the compiler to fall
into an infinite loop when characterizing a call to the procedure.
Following a suggestion from Peter, I fixed this be maintaining a set of
procedure symbols that had already been seen while characterizing a procedure.
This required passing a new parameter to the functions that characterized a
Procedure, a DummyArgument, and a DummyProcedure.
I also added several tests that will crash the compiler without this change.
Differential Revision: https://reviews.llvm.org/D96631
Split up MeasureSizeInBytes() so that array element sizes can be
calculated accurately; use the new API in some places where
DynamicType::MeasureSizeInBytes() was being used but the new
API performs better due to TypeAndShape having precise CHARACTER
length information.
Differential Revision: https://reviews.llvm.org/D95897
Analyze the shape of the result of TRANSFER(ptr,array) correctly
when "ptr" is an array of deferred shape. Fixing this bug led to
some refactoring and concentration of common code in TypeAndShape
member functions with code in general shape and character length
analysis, and this led to some regression test failures that have
all been cleaned up.
Differential Revision: https://reviews.llvm.org/D95744
* IsArrayElement() needs another option to control whether it
should ignore trailing component references.
* Add IsObjectPointer().
* Add const Scope& variants of IsFunction() and IsProcedure().
* Make TypeAndShape::Characterize() work with procedure bindings.
* Handle CHARACTER length in MeasureSizeInBytes().
* Fine-tune FindExternallyVisibleObject()'s handling of dummy arguments
to conform with Fortran 2018: only INTENT(IN) and dummy pointers
in pure functions signify; update two tests accordingly.
Also: resolve some stylistic inconsistencies and add a missing
"const" in the expression traversal template framework.
Differential Revision: https://reviews.llvm.org/D95011
In some contexts, including the motivating case of determining whether
the expressions that define the shape of a variable are "constant expressions"
in the sense of the Fortran standard, expression rewriting via Fold()
is not necessary, and should not be required. The inquiry intrinsics LBOUND,
UBOUND, and SIZE work correctly now in specification expressions and are
classified correctly as being constant expressions (or not). Getting this right
led to a fair amount of API clean-up as a consequence, including the
folding of shapes and TypeAndShape objects, and new APIs for shapes
that do not fold for those cases where folding isn't needed. Further,
the symbol-testing predicate APIs in Evaluate/tools.h now all resolve any
associations of their symbols and work transparently on use-, host-, and
construct-association symbols; the tools used to resolve those associations have
been defined and documented more precisely, and their clients adjusted as needed.
Differential Revision: https://reviews.llvm.org/D94561
STORAGE_SIZE() is a standard inquiry intrinsic (size in bits
of an array element of the same type as the argument); SIZEOF()
is a common extension that returns the size in bytes of its
argument; C_SIZEOF() is a renaming of SIZEOF() in module ISO_C_BINDING.
STORAGE_SIZE() and SIZEOF() are implemented via rewrites to
expressions; these expressions will be constant when the necessary
type parameters and bounds are also constant.
Code to calculate the sizes of types (with and without alignment)
was isolated into Evaluate/type.* and /characteristics.*.
Code in Semantics/compute-offsets.* to calculate sizes and alignments
of derived types' scopes was exposed so that it can be called at type
instantiation time (earlier than before) so that these inquiry intrinsics
could be called from specification expressions.
Differential Revision: https://reviews.llvm.org/D93322
This patch plugs many holes in static initializer semantics, improves error
messages for default initial values and other component properties in
parameterized derived type instantiations, and cleans up several small
issues noticed during development. We now do proper scalar expansion,
folding, and type, rank, and shape conformance checking for component
default initializers in derived types and PDT instantiations.
The initial values of named constants are now guaranteed to have been folded
when installed in the symbol table, and are no longer folded or
scalar-expanded at each use in expression folding. Semantics documentation
was extended with information about the various kinds of initializations
in Fortran and when each of them are processed in the compiler.
Some necessary concomitant changes have bulked this patch out a bit:
* contextual messages attachments, which are now produced for parameterized
derived type instantiations so that the user can figure out which
instance caused a problem with a component, have been added as part
of ContextualMessages, and their implementation was debugged
* several APIs in evaluate::characteristics was changed so that a FoldingContext
is passed as an argument rather than just its intrinsic procedure table;
this affected client call sites in many files
* new tools in Evaluate/check-expression.cpp to determine when an Expr
actually is a single constant value and to validate a non-pointer
variable initializer or object component default value
* shape conformance checking has additional arguments that control
whether scalar expansion is allowed
* several now-unused functions and data members noticed and removed
* several crashes and bogus errors exposed by testing this new code
were fixed
* a -fdebug-stack-trace option to enable LLVM's stack tracing on
a crash, which might be useful in the future
TL;DR: Initialization processing does more and takes place at the right
times for all of the various kinds of things that can be initialized.
Differential Review: https://reviews.llvm.org/D92783
Ensure that character length is properly calculated for
actual arguments to intrinsics, and that source provenance
information is available when expression analysis calls
folding in cases where the length is invalid.
Differential revision: https://reviews.llvm.org/D90636
Check INTENT(OUT)/INTENT(INOUT) constraints for actual argument
of intrinsic procedure calls.
- Adding a common::Intent field to the IntrinsicDummyArgument
in the intrinsic table.
- Propagating it to the DummyDataObject intent field so that it can
later be used in CheckExplicitDataArg semantic checks.
- Add related tests.
- Fix regression (C846 false error), C846 INTENT(OUT) rule does
not apply to intrinsic call. Propagate the information that we
are in an intrinsic call up to CheckExplicitDataArg (that is
doing this check). Still enforce C846 on intrinsics other than MOVE_ALLOC (for which
allocatable coarrays are explicitly allowed) since it's not clear it is allowed in all
intrinsics and allowing this would lead to runtime penalties in the intrinsic runtime.
Differential Revision: https://reviews.llvm.org/D89473
Calling "ASSOCATED(NULL()) was causing an internal check of the compiler to
fail.
I fixed this by changing the entry for "ASSOCIATED" in the intrinsics table to
accept "AnyPointer" which contains a new "KindCode" of "pointerType". I also
changed the function "FromActual()" to return a typeless intrinsic when called
on a pointer, which duplicates its behavior for BOZ literals. This required
changing the analysis of procedure arguments. While testing processing for
procedure arguments, I found another bad call to `CHECK()` which I fixed.
I made several other changes:
-- I implemented constant folding for ASSOCIATED().
-- I fixed handling of NULL() in relational operations.
-- I implemented semantic analysis for ASSOCIATED().
-- I noticed that the semantics for ASSOCIATED() are similar to those for
pointer assignment. So I extracted the code that pointer assignment uses
for procedure pointer compatibility to a place where it could be used by
the semantic analysis for ASSOCIATED().
-- I couldn't figure out how to make the general semantic analysis for
procedure arguments work with ASSOCIATED()'s second argument, which can
be either a pointer or a target. So I stopped using normal semantic
analysis for arguments for ASSOCIATED().
-- I added tests for all of this.
Differential Revision: https://reviews.llvm.org/D88313
CHARACTER length expressions were not always being
captured or computed as part of procedure "characteristics",
leading to test failures due to an inability to compute
memory size expressions accurately.
Differential revision: https://reviews.llvm.org/D88689
Represent FINAL subroutines in the symbol table entries of
derived types. Enforce constraints. Update tests that have
inadvertent violations or modified messages. Added a test.
The specific procedure distinguishability checking code for generics
was used to enforce distinguishability of FINAL procedures.
(Also cleaned up some confusion and redundancy noticed in the
type compatibility infrastructure while digging into that area.)
Differential revision: https://reviews.llvm.org/D88613
Fortran 2018 15.4.2.2(4)(c) says nonassumed or explicit non-constant
length parameter require explicit interface. The "nonassumed" part was
missing in f18 characteristic analysis causing CanBeCalledViaImplicitInterface
to return false for `CHARACTER(*) function foo()` like interfaces.
Reviewed By: klausler
Differential Revision: https://reviews.llvm.org/D88075
The shape (esp. the size) of the result of a call to TRANSFER
is implemented according to the definition in the standard.
Differential Revision: https://reviews.llvm.org/D85866
Rolls up small changes across the frontend to prepare for the large
forthcoming patch (part 4/4) that completes DATA statement processing
via conversion to initializers.
Reviewed By: PeteSteinfeld
Differential Revision: https://reviews.llvm.org/D82137
This patch replaces the occurrence of std::ostream by llvm::raw_ostream.
In LLVM Coding Standards[1] "All new code should use raw_ostream
instead of ostream".[1]
As a consequence, this patch also replaces the use of:
std::stringstream by llvm::raw_string_ostream or llvm::raw_ostream*
std::ofstream by llvm::raw_fd_ostream
std::endl by '\n' and flush()[2]
std::cout by llvm::outs() and
std::cerr by llvm::errs()
It also replaces std::strerro by llvm::sys::StrError** , but NOT in Fortran
runtime libraries
*std::stringstream were replaced by llvm::raw_ostream in all methods that
used std::stringstream as a parameter. Moreover, it removes the pointers to
these streams.
[1]https://llvm.org/docs/CodingStandards.html
[2]https://releases.llvm.org/2.5/docs/CodingStandards.html#ll_avoidendl
Signed-off-by: Caroline Concatto <caroline.concatto@arm.com>
Running clang-format-7
Signed-off-by: Caroline Concatto <caroline.concatto@arm.com>
Removing residue of ostream library
Signed-off-by: Caroline Concatto <caroline.concatto@arm.com>
Original-commit: flang-compiler/f18@a3507d44b8
Reviewed-on: https://github.com/flang-compiler/f18/pull/1047
When a module subprogram has the MODULE prefix the following must match
with the corresponding separate module procedure interface body:
- C1549: characteristics and dummy argument names
- C1550: binding label
- C1551: NON_RECURSIVE prefix
SubprogramMatchHelper performs all of these checks.
Rename separate-module-procs.f90 to separate-mp01.f90 so we can have
separate-mp02.f90 (etc).
Make ShapesAreCompatible public in characteristics.h.
Add Scope::IsSubmodule.
Original-commit: flang-compiler/f18@d121578af1
Reviewed-on: https://github.com/flang-compiler/f18/pull/1080
Daniil Dudkin