Commit Graph

6 Commits

Author SHA1 Message Date
peter klausler 6aa3591e98 [flang] Implement STORAGE_SIZE(), SIZEOF(), C_SIZEOF()
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
2020-12-15 17:26:20 -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 641ede93ef [flang] Improve initializer semantics, esp. for component default values
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
2020-12-07 14:40:41 -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 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