If you specify a type-bound procedure with an alternate return, there
will be no symbol associated with that dummy argument. In such cases,
the compiler's list of dummy arguments will contain a nullptr. In our
analysis of the PASS arguments of type-bound procedures, we were
assuming that all dummy arguments had non-null symbols associated with
them and were using that assumption to get the name of the dummy
argument. This caused the compiler to try to dereference a nullptr.
I fixed this by explicitly checking for a nullptr and, in such cases, emitting
an error message. I also added tests that contain type-bound procedures with
alternate returns in both legal and illegal constructs to ensure that semantic
analysis is working for them.
Differential Revision: https://reviews.llvm.org/D98430
You can define a base type with a type-bound procedure which is erroneously
missing a NOPASS attribute and then define another type that extends the base
type and overrides the erroneous procedure. In this case, when we perform
semantic checking on the overriding procedure, we verify the "pass index" of
the overriding procedure. The attempt to get the procedure's pass index fails
a call to CHECK().
I fixed this by calling SetError() on the symbol of the overridden procedure in
the base type. Then, I check HasError() before executing the code that invokes
the failing call to CHECK(). I also added a test that will cause the compiler
to fail the call to CHECK() without this change.
Differential Revision: https://reviews.llvm.org/D98355
C843 states that "An entity with the INTENT attribute shall be a dummy
data object or a dummy procedure pointer." This change enforces that
and fixes some tests that erroneously violated this rule.
Differential Revision: https://reviews.llvm.org/D94781
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
Before this patch, the Restorer depended on copy elision to happen.
Without copy elision, the function ScopedSet calls the move constructor
before its dtor. The dtor will prematurely restore the reference to the
original value.
Instead of relying the compiler to not use the Restorer's copy
constructor, delete its copy and assign operators. Hence, callers cannot
move or copy a Restorer object anymore, and have to explicitly provide
the reset state. ScopedSet avoids calling move/copy operations by
relying on unnamed return value optimization, which is mandatory in
C++17.
Reviewed By: klausler
Differential Revision: https://reviews.llvm.org/D88797
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
When the same generic name is use-associated from two modules, the
generics are merged into a single one in the current scope. This change
fixes some bugs in that process.
When a generic is merged, it can have two specific procedures with the
same name as the generic (c.f. module m7c in modfile07.f90). We were
disallowing that by checking for duplicate names in the generic rather
than duplicate symbols. Changing `namesSeen` to `symbolsSeen` in
`ResolveSpecificsInGeneric` fixes that.
We weren't including each USE of those generics in the .mod file so in
some cases they were incorrect. Extend GenericDetails to specify all
use-associated symbols that are merged into the generic. This is used to
write out .mod files correctly.
The distinguishability check for specific procedures of a generic
sometimes have to refer to procedures from a use-associated generic in
error messages. In that case we don't have the source location of the
procedure so adapt the message to say where is was use-associated from.
This requires passing the scope through the checks to make that
determination.
Differential Revision: https://reviews.llvm.org/D92492
Fortran's FINAL feature is sensitive to object rank.
When an object's rank excludes it from finalization, but
the type has FINAL subroutines for other ranks, emit
a warning. This should be especially helpful in the
case of a scalar FINAL subroutine not being declared
(IMPURE) ELEMENTAL.
Differential revision: https://reviews.llvm.org/D90495
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
Change how generic operators and assignments are checked for
distinguishable procedures. Because of how they are invoked, available
type-bound generics and normal generics all have to be considered
together. This is different from how generic names are checked.
Move common part of checking into DistinguishabilityHelper so that it
can be used in both cases after the appropriate procedures have been
added.
Cache result of Procedure::Characterize(Symbol) in a map in
CheckHelper so that we don't have to worry about passing the
characterized Procedures around or the cost of recomputing them.
Add MakeOpName() to construct names for defined operators and assignment
for using in error messages. This eliminates the need for different
messages in those cases.
When the procedures for a defined operator or assignment are undistinguishable,
include the type name in the error message, otherwise it may be ambiguous.
Add missing check that procedures for defined operators are functions
and that their dummy arguments are INTENT(IN) or VALUE.
Differential Revision: https://reviews.llvm.org/D87341
A specification expression can reference an implicitly declared variable
in the host procedure. Because we have to process specification parts
before execution parts, this may be the first time we encounter the
variable. We were assuming the variable was implicitly declared in the
scope where it was encountered, leading to an error because local
variables may not be referenced in specification expressions.
The fix is to tentatively create the implicit variable in the host
procedure because that is the only way the specification expression can
be valid. We mark it with the flag `ImplicitOrError` to indicate that
either it must be implicitly defined in the host (by being mentioned in
the execution part) or else its use turned out to be an error.
We need to apply the implicit type rules of the host, which requires
some changes to implicit typing.
Variables in common blocks are allowed to appear in specification expressions
(because they are not locals) but the common block definition may not appear
until after their use. To handle this we create common block symbols and object
entities for each common block object during the `PreSpecificationConstruct`
pass. This allows us to remove the corresponding code in the main visitor and
`commonBlockInfo_.curr`. The change in order of processing causes some
different error messages to be emitted.
Some cleanup is included with this change:
- In `ExpressionAnalyzer`, if an unresolved name is encountered but
no error has been reported, emit an internal error.
- Change `ImplicitRulesVisitor` to hide the `ImplicitRules` object
that implements it. Change the interface to pass in names rather
than having to get the first character of the name.
- Change `DeclareObjectEntity` to have the `attrs` argument default
to an empty set; that is the typical case.
- In `Pre(parser::SpecificationPart)` use "structured bindings" to
give names to the pieces that make up a specification-part.
- Enhance `parser::Unwrap` to unwrap `Statement` and `UnlabeledStatement`
and make use of that in PreSpecificationConstruct.
Differential Revision: https://reviews.llvm.org/D86322
A SAVE statement with no entity list applies the SAVE attribute only to
the entities that it is allowed on. We were applying it to automatic
data objects and reporting an error that they can't have SAVE.
The fix is to change `DeclarationVisitor::CheckSaveAttr` to check for
automatic objects. That controls both checking and setting the
attribute. This allows us to remove the check from `CheckSpecExpr`
(along with `symbolBeingChecked_`). Also, it was only called on constant
objects so the non-const overload can be eliminated.
The check in `CheckSpecExpr` is replaced by an explicit check for
automatic objects in modules. This caught an error in modfile03.f90 so
that part of the test was eliminated.
Differential Revision: https://reviews.llvm.org/D83899
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
Summary:
Some Symbol-related functions used in Evaluate were moved to
Evaluate/tools.h. This includes changing some member functions that were
replaced by non-member functions `IsDummy`, `GetUsedModule`, and
`CountLenParameters`.
Some member functions were made inline in `Scope`, `Symbol`,
`ArraySpec`, and `DeclTypeSpec`. The definitions were preceded by a
comment explaining why they are inline.
`IsConstantShape` was expanded inline in `IsDescriptor` because it isn't
used anywhere else
After this change, at least when compiling with clang on macos,
`libFortranEvaluate.a` has no undefined symbols that are satisfied by
`libFortranSemantics.a`.
Reviewers: klausler, PeteSteinfeld, sscalpone, jdoerfert, DavidTruby
Reviewed By: PeteSteinfeld
Subscribers: llvm-commits
Tags: #flang, #llvm
Differential Revision: https://reviews.llvm.org/D80762
Summary:
Many of these were already implemented, and I just annotated the tests and/or
the code.
C752 was a simple check to verify that CONTIGUOUS components are arrays with
C754 proved to be virtually identical to C750 that I implemented previously.
This caused me to remove the distinction between specification expressions for
type parameters and bounds expressions that I'd previously created.
the POINTER attribute.
I also changed the error messages to specify that errors in specification
expressions could arise from either bad derived type components or type
parameters.
In cases where we detect a type param that was not declared, I created a symbol
marked as erroneous. That avoids subsequent semantic process for expressions
containing the symbol. This change caused me to adjust tests resolve33.f90 and
resolve34.f90. Also, I avoided putting out error messages for erroneous type
param symbols in `OkToAddComponent()` in resolve-names.cpp and in
`EvaluateParameters()`, type.cpp.
C756 checks that procedure components have the POINTER attribute.
Reviewers: tskeith, klausler, DavidTruby
Subscribers: llvm-commits
Tags: #llvm, #flang
Differential Revision: https://reviews.llvm.org/D79798
Summary:
Most of these checks were already implemented, and I just added references to
them to the code and tests. Also, much of this code was already
reviewed in the old flang/f18 GitHub repository, but I didn't get to
merge it before we switched repositories.
I implemented the check for C747 to not allow coarray components in derived
types that are of type C_PTR, C_FUNPTR, or type TEAM_TYPE.
I implemented the check for C748 that requires a data component whose type has
a coarray ultimate component to be a nonpointer, nonallocatable scalar and not
be a coarray.
I implemented the check for C750 that adds additional restrictions to the
bounds expressions of a derived type component that's an array.
These bounds expressions are sepcification expressions as defined in
10.1.11. There was already code in lib/Evaluate/check-expression.cpp to
check semantics for specification expressions, but it did not check for
the extra requirements of C750.
C750 prohibits specification functions, the intrinsic functions
ALLOCATED, ASSOCIATED, EXTENDS_TYPE_OF, PRESENT, and SAME_TYPE_AS. It
also requires every specification inquiry reference to be a constant
expression, and requires that the value of the bound not depend on the
value of a variable.
To implement these additional checks, I added code to the intrinsic proc
table to get the intrinsic class of a procedure. I also added an
enumeration to distinguish between specification expressions for
derived type component bounds versus for type parameters. I then
changed the code to pass an enumeration value to
"CheckSpecificationExpr()" to indicate that the expression was a bounds
expression and used this value to determine whether to emit an error
message when violations of C750 are found.
I changed the implementation of IsPureProcedure() to handle statement
functions and changed some references in the code that tested for the
PURE attribute to call IsPureProcedure().
I also fixed some unrelated tests that got new errors when I implemented these
new checks.
Reviewers: tskeith, DavidTruby, sscalpone
Subscribers: jfb, llvm-commits
Tags: #llvm, #flang
Differential Revision: https://reviews.llvm.org/D79263
In most cases, I just added the contraint names to the code and tests.
I implemented the following checks:
- C736 A child type with a coarray ultimate component must have a parent with
a coarray ultimate component.
- C737 A child type with and EVENT_TYPE or LOCK_TYPE component must have a
parent either which is EVENT_TYPE or LOCK_TYPE or a type with an EVENT_TYPE
or LOCK_TYPE component.
- C740 Sequence types must contain at least on component
- C740 Data components of sequence types must either be of an intrinsic type
or a sequenced derived type.
After implementing these checks, some tests had new errors unrelated to their
original purpose, so I fixed them.
Original-commit: flang-compiler/f18@098f01bc47
Reviewed-on: https://github.com/flang-compiler/f18/pull/1097
The full list of constraints is C727, C728, C729, C730, C743, C755, C759, C778,
and C1543.
I added a function to tools.cpp to check to see if a symbol name is the name
of an intrinsic type.
The biggest change was to resolve-names.cpp to check to see if attributes were
either duplicated or in conflict with each other. I changed all locations
where attributes were set to check for duplicates or conflicts.
I also added tests for all checks and annotated the tests and code with the
numbers of the constraints being tested/checked.
Original-commit: flang-compiler/f18@3f30e8a61e
Reviewed-on: https://github.com/flang-compiler/f18/pull/1084
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
If the pure context check succeeds, call `WhyNotModifiable` to verify
the LHS can be modified.
Detect assignment to whole assumed-size array.
Change `IsVariable` to return false for a parameter or a component or
array reference whose base it a parameter.
When analyzing an assignment statement, report an error if the LHS is
a constant expression. Otherwise it might get folded and when we detect
the problem later the error will be confusing.
Handle Substring on LHS of assignment. Change ExtractDataRef and IsVariable
to work on a Substring.
Fix IsImpliedShape and IsAssumedSize predicates in ArraySpec.
Fix C709 check in check-declarations.cpp.
Original-commit: flang-compiler/f18@f2d2657aab
Reviewed-on: https://github.com/flang-compiler/f18/pull/1050
I've updated the compiler and test source with references to the contraints at
the points where they were enforced and tested. Many of these were already
implemented and required no code change. A few constraint checks were both
implemented and tested, and I only added references to the constraint
numbers in the compiler source and tests. Here are the things I had to
implement:
Constraint C716 states that, in a REAL constant, if both a kind-param and an
exponent letter appear, the exponent letter must be 'E'.
Constraints C715 and C719 require that a KIND value be actually implemented.
Constraint C722 requires that functions that return assumed-length character
types are external.
Constraint C726 disallows assumed lenght charater types for dummy arguments and
return types.
Original-commit: flang-compiler/f18@45998741e5
Reviewed-on: https://github.com/flang-compiler/f18/pull/1031
Tree-same-pre-rewrite: false
Peter Steinfeld