Implements part of the legacy "DEC structures" feature from
VMS Fortran. STRUCTUREs are processed as if they were derived
types with SEQUENCE. DATA-like object entity initialization
is supported as well (e.g., INTEGER FOO/666/) since it was used
for default component initialization in structures. Anonymous
components (named %FILL) are also supported.
These features, and UNION/MAP, were already being parsed.
An omission in the collection of structure field names in the
case of nested structures with entity declarations was fixed
in the parser.
Structures are supported in modules, but this is mostly for
testing purposes. The names of fields in structures accessed
via USE association cannot appear with dot notation in client
code (at least not yet). DEC structures antedate Fortran 90,
so their actual use in applications should not involve modules.
This patch does not implement UNION/MAP, since that feature
would impose difficulties later in lowering them to MLIR types.
In the meantime, if they appear, semantics will issue a
"not yet implemented" error message.
Differential Revision: https://reviews.llvm.org/D117151
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
Implement rest of DATA statement semantics and conversion of
DATA statement initializations into static initializers of
objects in their symbol table entries.
Reviewed By: tskeith, PeteSteinfeld
Differential Revision: https://reviews.llvm.org/D82207
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:
Updates recent work on DATA statement semantic checking in
flang/lib/Semantics/check-data.{h,cpp} to use the compiler's
internal representation for typed expressions rather than working
on the raw parse tree. Saves the analyzed expressions for DATA
statement values as parse tree decorations because they'll soon be
needed in lowering. Corrects wording of some error messages.
Fixes a bug in constant expression checking: structure constructors
are not constant expressions if they set an allocatable component
to anything other than NULL.
Includes infrastructure changes to make this work, some renaming
to reflect the fact that the implied DO loop indices tracked by
expression analysis are not (just) from array constructors, remove
some dead code, and improve some comments.
Reviewers: tskeith, sscalpone, jdoerfert, DavidTruby, anchu-rajendran, schweitz
Reviewed By: tskeith, anchu-rajendran, schweitz
Subscribers: llvm-commits, flang-commits
Tags: #flang, #llvm
Differential Revision: https://reviews.llvm.org/D78834
Peter Klausler