When one value is used multiple times for separate return values, we
need to copy it to produce a new value, so that each value can be
allocated a different register.
The new wasmparser API provides dedicated reader types for each section
type, which significantly simplifies the code.
This also changes WasmError::from_binary_reader_error into a From
trait so that we don't have to do .map_err(from_binary_reader_error)
throughout the code.
Passing it by reference was an artifact of an earlier version of the
TargetFrontendConfig code, but it's no longer needed, as
TargetFrontendConfig is now a Copy type.
* Introduce a `TargetFrontendConfig` type.
`TargetFrontendConfig` is information specific to the target which is
provided to frontends to allow them to produce Cranelift IR for the
target. Currently this includes the pointer size and the default calling
convention.
The default calling convention is now inferred from the target, rather
than being a setting. cranelift-native is now just a provider of target
information, rather than also being a provider of settings, which gives
it a clearer role.
And instead of having cranelift-frontend routines require the whole
`TargetIsa`, just require the `TargetFrontendConfig`, and add a way to
get the `TargetFrontendConfig` from a `Module`.
Fixes#529.
Fixes#555.
We no longer need the Ubuntu LTS restriction, so now the only only
constraint I'm aware of is Firefox's policy. Fortunately, that tracks
the latest stable delayed by only two weeks. So this puts is at
Rust 1.29 now.
* Use a type to represent wasm table indices.
* Use a type to represent wasm global variable indices.
* Use a type to represent wasm memory indices.
* Use a type to represent wasm signature indices.
* Use PrimaryMap instead of Vec to protect against using wrong indices.
* Rename size to base_size and introduce a compute_size function;
* Add infra to inspect in/outs registers when computing the size of an instruction;
* Remove the GPR_SAFE_DEREF and GPR_ZERO_DEREF_SAFE register classes on x86 (fixes#335);
* Put TargetIsa's emit_inst under a "testing_hooks" feature.
In practice, TargetIsa's emit_inst pulls in its own instantiation
of the target-specifi `emit_inst` functions, which can be quite
large, and LTO doesn't eliminate them because they're held live
by TargetIsa's vtable.
Fortunately, this function is only used by tests, so we can put
it behind a feature flag.
Fixes#530.
* Add comments for `emit_inst` to clarify its purpose.
