I noticed, when building an app for a 32 bit target, that some rustc flatbuffers would fail to validate, when a uint64 was serialized by a i686 machine.
I reproduced this by checking out the flatbuffers and running the test suite, and noticed that one of the test cases specifically about uint64 alignment failed on this target:
rustup target add i686-unknown-linux-gnu
cd flatbuffers32/tests/rust_usage_test
cargo test --target=i686-unknown-linux-gnu
cargo test --test integration_test --target=i686-unknown-linux-gnu push_u8_u64_alignment
warning: unused import: `MapReaderIndexer`
--> /home/danielrh/dev/flatbuffers32/rust/flexbuffers/src/reader/mod.rs:29:26
|
29 | pub use map::{MapReader, MapReaderIndexer};
| ^^^^^^^^^^^^^^^^
|
= note: `#[warn(unused_imports)]` on by default
warning: `flexbuffers` (lib) generated 1 warning (run `cargo fix --lib -p flexbuffers` to apply 1 suggestion)
warning: variable `Message` should have a snake case name
--> tests/../../rust_namer_test/rust_namer_test/game_message_wrapper_generated.rs:51:9
|
51 | let Message = match self.Message_type() {
| ^^^^^^^ help: convert the identifier to snake case: `message`
|
= note: `#[warn(non_snake_case)]` on by default
warning: method `Message_type` should have a snake case name
--> tests/../../rust_namer_test/rust_namer_test/game_message_wrapper_generated.rs:76:10
|
76 | pub fn Message_type(&self) -> GameMessage {
| ^^^^^^^^^^^^ help: convert the identifier to snake case: `message_type`
warning: method `Message` should have a snake case name
--> tests/../../rust_namer_test/rust_namer_test/game_message_wrapper_generated.rs:83:10
|
83 | pub fn Message(&self) -> Option<flatbuffers::Table<'a>> {
| ^^^^^^^ help: convert the identifier to snake case: `message`
warning: structure field `Message_type` should have a snake case name
--> tests/../../rust_namer_test/rust_namer_test/game_message_wrapper_generated.rs:156:9
|
156 | pub Message_type: GameMessage,
| ^^^^^^^^^^^^ help: convert the identifier to snake case: `message_type`
warning: structure field `Message` should have a snake case name
--> tests/../../rust_namer_test/rust_namer_test/game_message_wrapper_generated.rs:157:9
|
157 | ...ub Message: Option<flatbuffers::WIPOffset<flatbuffers::UnionWIPOffse...
| ^^^^^^^ help: convert the identifier to snake case: `message`
warning: method `add_Message_type` should have a snake case name
--> tests/../../rust_namer_test/rust_namer_test/game_message_wrapper_generated.rs:175:10
|
175 | pub fn add_Message_type(&mut self, Message_type: GameMessage) {
| ^^^^^^^^^^^^^^^^ help: convert the identifier to snake case: `add_message_type`
warning: variable `Message_type` should have a snake case name
--> tests/../../rust_namer_test/rust_namer_test/game_message_wrapper_generated.rs:175:38
|
175 | pub fn add_Message_type(&mut self, Message_type: GameMessage) {
| ^^^^^^^^^^^^ help: convert the identifier to snake case: `message_type`
warning: method `add_Message` should have a snake case name
--> tests/../../rust_namer_test/rust_namer_test/game_message_wrapper_generated.rs:179:10
|
179 | pub fn add_Message(&mut self, Message: flatbuffers::WIPOffset<flatbuf...
| ^^^^^^^^^^^ help: convert the identifier to snake case: `add_message`
warning: variable `Message` should have a snake case name
--> tests/../../rust_namer_test/rust_namer_test/game_message_wrapper_generated.rs:179:33
|
179 | ...f, Message: flatbuffers::WIPOffset<flatbuffers::UnionWIPOffset>) {
| ^^^^^^^ help: convert the identifier to snake case: `message`
warning: structure field `Message` should have a snake case name
--> tests/../../rust_namer_test/rust_namer_test/game_message_wrapper_generated.rs:234:7
|
234 | pub Message: GameMessageT,
| ^^^^^^^ help: convert the identifier to snake case: `message`
warning: variable `Message_type` should have a snake case name
--> tests/../../rust_namer_test/rust_namer_test/game_message_wrapper_generated.rs:248:9
|
248 | let Message_type = self.Message.game_message_type();
| ^^^^^^^^^^^^ help: convert the identifier to snake case: `message_type`
warning: variable `Message` should have a snake case name
--> tests/../../rust_namer_test/rust_namer_test/game_message_wrapper_generated.rs:249:9
|
249 | let Message = self.Message.pack(_fbb);
| ^^^^^^^ help: convert the identifier to snake case: `message`
warning: `rust_usage_test` (test "integration_test") generated 12 warnings
Finished test [unoptimized + debuginfo] target(s) in 0.03s
Running tests/integration_test.rs (target/i686-unknown-linux-gnu/debug/deps/integration_test-7966cfe9a55a34cc)
running 1 test
test flatbuffers_tests::push_impls::push_u8_u64_alignment ... FAILED
failures:
---- flatbuffers_tests::push_impls::push_u8_u64_alignment stdout ----
thread 'flatbuffers_tests::push_impls::push_u8_u64_alignment' panicked at tests/integration_test.rs:2360:9:
assertion `left == right` failed
left: [2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]
right: [2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
failures:
flatbuffers_tests::push_impls::push_u8_u64_alignment
test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 261 filtered out; finished in 0.00s
error: test failed, to rerun pass `--test integration_test`
danielrh@vectron:~/dev/flatbuffers32/tests/rust_usage_test$
This was the same issue that was leading to failures with my rust application on a 32 bit target; the 32 bit rust target failed to pad the 64 bit value to align with 64 bits. Perhaps it had to do with usage of platform-specific core::mem::{align_of, size_of}; that may be defined differently on architectures with more relaxed requirements than the flatbuffer serialization format.
I noticed, when building an app for a 32 bit target, that some rustc flatbuffers would fail to validate, when a uint64 was serialized by a i686 machine.
I reproduced this by checking out the flatbuffers and running the test suite, and noticed that one of the test cases specifically about uint64 alignment failed on this target:
This was the same issue that was leading to failures with my rust application on a 32 bit target; the 32 bit rust target failed to pad the 64 bit value to align with 64 bits. Perhaps it had to do with usage of platform-specific
core::mem::{align_of, size_of};that may be defined differently on architectures with more relaxed requirements than the flatbuffer serialization format.