Commit Graph

15 Commits

Author SHA1 Message Date
Peter Klausler 2d8b6a4784 [flang] Add explanatory messages to grammar for language extensions
Extend "extension<LanguageFeature>()" to incorporate an explanatory
message better than the current generic "nonstandard usage:".

Differential Revision: https://reviews.llvm.org/D122035
2022-03-18 16:14:27 -07:00
Peter Klausler 6bd72fa661 [flang] Allow extension cases of EQUIVALENCE with optional warnings
EQUIVALENCE storage association of objects whose types are not
both default-kind numeric storage sequences, or not both default-kind
character storage sequences, are not standard conformant.
However, most Fortran compilers admit such usage, with warnings
in strict conformance mode.  This patch allos EQUIVALENCE of objects
that have sequence types that are either identical, both numeric
sequences (of default kind or not), or both character sequences.
Non-sequence types, and sequences types that are not homogeneously
numeric or character, remain errors.

Differential Revision: https://reviews.llvm.org/D119848
2022-02-15 10:21:38 -08:00
Peter Klausler c14cf92b5a [flang] Implement semantics for DEC STRUCTURE/RECORD
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
2022-01-13 13:17:13 -08:00
peter klausler f0ffc690d5 [flang] Fix parsing of WRITE(I+J) with more accurate look-ahead
The parsing of I/O units uses look-ahead to discriminate between
keywords, variables and expressions as part of distinguishing internal
from external I/O.  The look-ahead was inaccurate for variables that
appear as the initial parts of expressions.

Differential Revision: https://reviews.llvm.org/D95743
2021-02-01 09:07:40 -08:00
peter klausler 9a883bfa11 [flang] Clean up TODO comments and fix one (DATA constant ambiguity)
Remove resolved & moot TODO comments in Common/, Parser/,
and Evaluate/.  Address a pending one relating to parsing
ambiguity in DATA statement constants, handling it with
symbol table information in Semantics and adding a test.

Differential Revision: https://reviews.llvm.org/D93323
2020-12-15 13:36:07 -08:00
peter klausler 5349f99114 [flang] Correct handling of null pointer initializers
Fortran defines "null-init" null pointer initializers as
being function references, syntactically, that have to resolve
to calls to the intrinsic function NULL() with no actual
arguments.

Differential revision: https://reviews.llvm.org/D91657
2020-11-18 13:57:25 -08:00
peter klausler 3e86eda18c [flang] Allow "name: value" in compiler directives
Some legacy compiler directives use colons rather than
equals signs.

Differential revision: https://reviews.llvm.org/D89017
2020-10-08 10:01:37 -07:00
Tim Keith cf715717aa [flang] Allow compiler directives in more places
Allow compiler directives in the implicit-part and before USE statements
in the specification-part.

Differential Revision: https://reviews.llvm.org/D85693
2020-08-11 08:37:27 -07:00
peter klausler 8e2b4e50f2 [flang] Support <name>=<integer> syntax in compiler directives
Accept name=value as part of a !DIR$ compiler directive.  These
are currently ignored in semantics, but we should recognize
more directive forms to facilitate testing.  In due course,
these placeholding directive parsers will be replaced.

Reviewed By: sscalpone

Differential Revision: https://reviews.llvm.org/D84077
2020-07-17 17:05:38 -07:00
peter klausler a20d48d7d3 [flang] DATA stmt processing (part 4/4): Check & convert DATA
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
2020-06-19 13:26:20 -07:00
peter klausler 4171f80d54 [flang] DATA stmt processing (part 3/4): Remaining prep work
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
2020-06-19 09:09:05 -07:00
peter klausler a0226f9bff [flang] Dodge bogus uninitialized data warning from gcc 10.1 via code cleanup
G++ 10.1 emits inappropriate "use of uninitialized data" warnings when
compiling f18.  The warnings stem from two sites in templatized code
whose multiple instantiations magnified the number of warnings.

These changes dodge those warnings by making some innocuous changes to
the code.  In the parser, the idiom defaulted(cut >> x), which yields a
parser that always succeeds, has been replaced with a new equivalent
pass<T>() parser that returns a default-constructed value T{} in an
arguably more readable fashion.  This idiom was the only attestation of
the basic parser cut, so it has been removed and the remaining code
simplified.  In Evaluate/traverse.h, a return {}; was replaced with a
return of a default-constructed member.

Differential Revision: https://reviews.llvm.org/D81747
2020-06-12 10:05:05 -07:00
peter klausler 3a1afd8c3d Rework DATA statement semantics to use typed expressions
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
2020-04-25 10:29:34 -07:00
Tim Keith 1f8790050b [flang] Reformat with latest clang-format and .clang-format
Original-commit: flang-compiler/f18@9fe84f45d7
Reviewed-on: https://github.com/flang-compiler/f18/pull/1094
2020-03-28 21:00:16 -07:00
CarolineConcatto 64ab3302d5 [flang] [LLVMify F18] Compiler module folders should have capitalised names (flang-compiler/f18#980)
This patch renames the modules in f18 to use a capital letter in the
module name

Signed-off-by: Caroline Concatto <caroline.concatto@arm.com>

Original-commit: flang-compiler/f18@d2eb7a1c44
Reviewed-on: https://github.com/flang-compiler/f18/pull/980
2020-02-25 07:11:52 -08:00