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
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
peter klausler