The output size is stored as `size_t`, a 64-bit value. However, on a
big-endian system this would be truncated to 0 since the low memory
addresses wold be sent.
To fix this, we cast the `size_t` to `uint32_t` and send that. Note that
calling `htonl()` would also work, but casting is simpler and does not
require including platform-specific header files.
Note that the tests now run, but there are 59 unexpected failures.
Closes https://github.com/protocolbuffers/upb/issues/446
This brings upb into line with C++. PHP already checks this
internally, so this should not be an issue there. Ruby on the
other hand does not currently check this, so this change will
cause our Ruby implementation to reject some programs that
would otherwise have been accepted.
This matches an API already present in proto2
(const DescriptorPool* FileDescriptor::pool()).
However there is a slightly subtle implication here.
In proto2, the relationship between Descriptor and
MessageFactory is 1:many. You can create as many
DynamicMessageFactory instances as you want, and
each one will have its own independent DynamicMessage
prototype and computed layout for the same underlying
Descriptor. In practice the layouts will all be the same,
but one thing that could be distinct is that each can
have its own extension pool, which is a DescriptorPool
that will be searched for extensions when parsing.
In contrast, upb does not have a separate "message
factory" abstraction. That means that each upb_msgdef
has a single distinct layout, in other words a 1:1
correspondence between descriptor and layout. This means
that there is no way to create multiple message types
for the same descriptor that have distinct extension
pools. If you want a different set of extensions, you
must create a separate upb_symtab with a distinct set
of descriptors.
This change further entrenches that upb_filedef:upb_symtab
is a 1:1 relationship. A single upb_filedef cannot be a
member of multiple symbol tables. In practice this was
already true (there is no way to add a single filedef to
multiple symbol tables) but this change codifies this
1:1 relationship.
Joshua Haberman
Bernardo Bruning
Stan Hu
Matt Kulukundis
Esun Kim