The memory view interface added at 890bc2cdde is experimental new C-API
set. This feature permits extension libraries to share a memory area
that contains such a numerical array and a bitmap image. This is
designed by referring to Python's buffer protocol.
[[Feature #13767]]
[[Feature #14722]]
* Add buffer protocol
* Modify for some review comments
* Per-object buffer availability
* Rename to MemoryView from Buffer and make compilable
* Support integral repeat count in memory view format
* Support 'x' for padding bytes
* Add rb_memory_view_parse_item_format
* Check type in rb_memory_view_register
* Update dependencies in common.mk
* Add test of MemoryView
* Add test of rb_memory_view_init_as_byte_array
* Add native size format test
* Add MemoryView test utilities
* Add test of rb_memory_view_fill_contiguous_strides
* Skip spaces in format string
* Support endianness specifiers
* Update documentation
* Support alignment
* Use RUBY_ALIGNOF
* Fix format parser to follow the pack format
* Support the _ modifier
* Parse count specifiers in get_format_size function.
* Use STRUCT_ALIGNOF
* Fix test
* Fix test
* Fix total size for the case with tail padding
* Fix rb_memory_view_get_item_pointer
* Fix rb_memory_view_parse_item_format again
The only remaining use of this function was to get the internal
message object from an exception's hidden `mesg` instance
variable to allow it to be dumped wiithout converting to a string.
As discussed in #103, this exposes internal implementation details
of CRuby, and ultimately does not provide any real utility to the
user since they can't directly inspect this hidden variable. The
test change here is to reflect CRuby behavior that denies equality
if the internal message objects do not match, as is the case after
the exception has been loaded and now has a simple String value.
The impact to users is that exceptions with special hidden message
objects will convert those objects to String during marshaling
through YAML. I believe this only affects NameError and its
descendants, since users can't set this field directly on their
own exception types.
Fixes#103.
Now that RUBY_ALIGNOF behaves like C11's _Alignof. This is not
necessarily the best stack arrangement. We can just give up using
__builtin_alloca_with_align(), and let alloca choose what is optimal.
It is reported that on a system of i386 System V ABI, GCC returns 8 for
__alignof__(double). OTOH the ABI defines alignments of double to be 4,
and ISO/IEC 9899:2011 reads that _Alignof(double) shall return 4 on such
machine. What we want in ruby is 4 instead of 8 there. We cannot use
__alignof__.
Additionally, both old GCC / old clang return 8 for _Alignof(double) on
such platforms. They are their bugs, and already fixed in recent
versions. But we have to support older compilers for a while. Shall
check sanity of _Alignof.
Availability of `alignas` is checked in include/ruby/internal/stdalign.h
now. That does not need this configure check. Also as commented in the
header, we see `_Alignas` being inadequate for our purpose.
