Pads serialized wire command buffers to 8 bytes so that we don't have
misaligned write/reads which can cause SIGILL depending on platform and
compilation mode, i.e. -c dbg in google3 builds.
- Adds helpers for aligning sizeof calls.
- Adds constant for wire padding (8u).
- Modifies BufferConsumer to allocate according to padding. This
guarantees that when we [de]serialize stuff, the padding should be
equal on both sides.
- Modifies extra byte serialization code (adding CommandExtension
struct). This makes it clearer that each extension needs to be
padded independently. Otherwise, before in wire/client/Buffer.cpp,
since the read/write handle sizes were being passed as a sum, but
read out separately from the BufferConsumer, we corrupt our pointers.
- Adds some simple unit tests.
Bug: dawn:1334
Change-Id: Id80e7c01a34b9f01c3f02b3e6c04c3bb3ad0eff9
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/110501
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Loko Kung <lokokung@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
2e1b359087