commit 9e82ee25275e07e35f489f6feac543611f81fb83
author tymcauley <16469394+tymcauley@users.noreply.github.com> Fri Mar 08 04:06:25 2019 -0500
committer Robert <rw@users.noreply.github.com> Fri Mar 08 01:06:25 2019 -0800
tree 40ff1df617329f88f532a6db8d067043194bb6d6
parent e237f53bfcee593f813c502b888784c7fb081aa9

Fix rust crate for big-endian targets (#5229)

Thanks for tackling this, @tymcauley !

* big endian docker test -- wip

* tweaks

* tweaks

* tweaks

* docker tweaks

* fix conditional compilation issues

* reactivate other docker tests

* try some more cross-platform config (from tymcauley)

* Update tests/docker/languages/Dockerfile.testing.rust.big_endian.1_30_1

Co-Authored-By: rw <rw@users.noreply.github.com>

* Update tests/docker/languages/Dockerfile.testing.rust.big_endian.1_30_1

Co-Authored-By: rw <rw@users.noreply.github.com>

* Update tests/docker/languages/Dockerfile.testing.rust.big_endian.1_30_1

Co-Authored-By: rw <rw@users.noreply.github.com>

* Resolved Rust warnings during big-endian builds.

* Unify Rust test suites for x86 and MIPS builds.

Note that I had to add four extra packages to the MIPS `Dockerfile`:
`libexpat1`, `libmagic1`, `libmpdec2`, and `libreadline7`. For a reason
I couldn't identify, even the simplest Rust MIPS binaries run with
`qemu-mips` would fail with a segfault when run through this
`Dockerfile`. After installing the `gdb-multiarch` package to attempt to
debug the issue, the binaries ran successfully. I pared down the
packages installed by `gdb-multiarch`, and these four packages are the
minimum subset necessary to get Rust MIPS binaries running under
`qemu-mips`.

* Changed Rust tests to use `Vector`s instead of direct-slice-access.

The direct-slice-access method is not available on big-endian targets,
but `flatbuffers::Vector`s provide an array interface that is available
on all platforms.

* Resolved FooStruct endianness issues using explicit struct constructor.

This more closely resembles how FlatBuffers structs are constructed in
generated Rust code.

* Added explanation of how `FooStruct` parallels generated struct code.

Also collected duplicate implementations of `FooStruct` into a common
location.