Commit Graph

11 Commits

Author SHA1 Message Date
Tim Keith 044a71d828 [flang] Don't attempt to compute element size if no DynamicType
If an error has occurred a symbol may have a DeclTypeSpec but no
valid DynamicType. There is no need to compute the size of erroneous
symbols.

Also, we only need to process object entities and procedure entities.
All other kinds of symbols can be skipped.

This fixes another problem revealed by https://bugs.llvm.org/show_bug.cgi?id=47265

Differential Revision: https://reviews.llvm.org/D86484
2020-08-24 18:20:24 -07:00
Tim Keith b8bfe3586e [flang] Fix bug accessing implicit variable in specification expression
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
2020-08-24 12:53:46 -07:00
peter klausler fad31d6032 [flang] Implement shape analysis of TRANSFER intrinsic function result
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
2020-08-13 09:56:24 -07:00
peter klausler 4ac617f490 [flang] Handle DATA initialization of EQUIVALENCE'd objects
Objects that are storage associated by EQUIVALENCE and
initialized with DATA are initialized by creating a
compiler temporary data object in the same scope,
assigning it an offset, type, and size that covers the
transitive closure of the associated initialized original
symbols, and combining their initializers into one common
initializer for the temporary.

Some problems with offset assignment of EQUIVALENCE'd objects
in COMMON were exposed and corrected, and some more error
cases are checked.

Remove obsolete function.
Small bugfix (nested implied dos).
Add a test.
Fix struct/class warning.

Differential Revision: https://reviews.llvm.org/D85560
2020-08-07 16:39:23 -07:00
Tim Keith 2c662f3d3d [flang] Fix bug with intrinsic in type declaration stmt
When an instrinsic function is declared in a type declaration statement
we need to set the INTRINSIC attribute and (per 8.2(3)) ignore the
specified type.

To simplify the check, add IsIntrinsic utility to BaseVisitor.

Also, intrinsics and external procedures were getting assigned a size
and offset and they shouldn't be.

Differential Revision: https://reviews.llvm.org/D84702
2020-07-29 07:23:31 -07:00
peter klausler 31e6cd28a5 [flang] Implement cross-set EQUIVALENCE impossibility checking
Implement cross-set EQUIVALENCE impossibility checking; fixes
an infinite loop on an erroneous test.  Also fix substring
reference offset calculations in EQUIVALENCE discovered to
be incorrect during testing.

Reviewed By: tskeith

Differential Revision: https://reviews.llvm.org/D82993
2020-07-01 14:09:07 -07:00
peter klausler d1862eb845 [flang] DATA stmt processing (part 1/4): designator folding
Summary:
Add code to resolve constant Designators at compilation time
into a base Symbol, byte offset, and field size.  This is used in
later DATA statement processing to identify the static storage being
initialized by each object in a DATA statement.  Also implement
the reverse mapping so that Designators can be reconstructed for
use in error messages about (e.g.) duplicate initializers.

Reviewers: tskeith, PeteSteinfeld, sscalpone, jdoerfert, DavidTruby

Reviewed By: PeteSteinfeld

Subscribers: mgorny, llvm-commits, flang-commits

Tags: #flang, #llvm

Differential Revision: https://reviews.llvm.org/D82125
2020-06-18 15:25:21 -07:00
Tim Keith 14f49599cc [flang][NFC] Remove link-time dependency of Evaluate on Semantics
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
2020-05-29 16:39:14 -07:00
Tim Keith 54b35c0664 [flang][NFC] Replace "align" with "alignment"
In the places it is used as a noun, replace "align" with "alignment".

Differential Revision: https://reviews.llvm.org/D79520
2020-05-06 15:03:30 -07:00
Tim Keith 237d0e3c04 [flang] Handle EQUIVALENCE and COMMON in size and offset computations
Objects in common blocks have offsets relative to the start of the
common block, independent of the enclosing scope, so they are processed
first. Add alignment to CommonBlockDetails to record the required
alignment of the common block.

For equivalence sets, each object depends on the one that is forced to
occur first in memory. The rest are recorded in the dependents_ map and
have offsets assigned after the other symbols are done.

Differential Revision: https://reviews.llvm.org/D79347
2020-05-06 11:45:28 -07:00
Tim Keith c353ebbfa4 [flang] Compute sizes and offsets for symbols
Summary:
Add size and offset properties to symbols, representing their byte size
and offset within their enclosing scope.

Add size and align properties to scopes so that they are available for
scopes representing derived types.

Add ComputeOffsets pass over the symbol table to fill in those fields.

Compute descriptor size based on rank and length parameters. Extract
DerivedTypeSpec::NumLengthParameters from DynamicType::RequiresDescriptor
to share the code.

Add Scope::GetSymbols to get symbols in canonical order.
compute-offsets.cpp and mod-file.cpp both need to process symbols in the
order in which they are declared. Move the collecting of those symbols
into Scope so that it can be shared.

Add symbol size and offset to output of `-fdebug-dump-symbols` and use
that in some tests.

Still to do:
- make size and alignment rules configurable based on target
- use offsets to check EQUIVALENCE statements

Differential Revision: https://reviews.llvm.org/D78680
2020-04-23 14:54:34 -07:00