This commit implements registering unwind information for JIT functions on
Windows so that the operating system can both walk and unwind stacks containing
JIT frames.
Currently this only works with Cranelift as lightbeam does not emit unwind
information yet.
This commit also resets the stack guard page on Windows for stack overflow
exceptions, allowing reliable stack overflow traps.
With these changes, all previously disabled test suite tests (not including
the multi-value tests) on Windows are now passing.
Fixes#291.
* Migrate from failure to thiserror and anyhow
The failure crate invents its own traits that don't use
std::error::Error (because failure predates certain features added to
Error); this prevents using ? on an error from failure in a function
using Error. The thiserror and anyhow crates integrate with the standard
Error trait instead.
This change does not attempt to semantically change or refactor the
approach to error-handling in any portion of the code, to ensure that
the change remains straightforward to review. Modules using specific
differentiated error types move from failure_derive and derive(Fail) to
thiserror and derive(Error). Modules boxing all errors opaquely move
from failure::Error to anyhow. Modules using String as an error type
continue to do so. Code using unwrap or expect continues to do so.
Drop Display implementations when thiserror can easily derive an
identical instance.
Drop manual traversal of iter_causes; anyhow's Debug instance prints the
chain of causes by default.
Use anyhow's type alias anyhow::Result<T> in place of
std::result::Result<T, anyhow::Error> whenever possible.
* wasm2obj: Simplify error handling using existing messages
handle_module in wasm2obj manually maps
cranelift_codegen::isa::LookupError values to strings, but LookupError
values already have strings that say almost exactly the same thing.
Rely on the strings from cranelift.
* wasmtime: Rely on question-mark-in-main
The main() wrapper around rmain() completely matches the behavior of
question-mark-in-main (print error to stderr and return 1), so switch to
question-mark-in-main.
* Update to walrus 0.13 and wasm-webidl-bindings 0.6
Both crates switched from failure to anyhow; updating lets us avoid a
translation from failure to anyhow within wasmtime-interface-types.
* Remove cmake/bindgen/llvm from wasmtime-runtime
This commit removes the cmake/bindgen dependency (which removes the need
for `llvm-config`) from the `wasmtime-runtime` crate. The C++ code is
instead compiled with the `cc` crate (it's just one file anyway) and the
interface is handwritten since it's quite small anyway.
Some other changes are:
* The `TrapContext` type in C++ was removed since it was unused, and it
was moved to Rust with a `Cell` on each field.
* Functions between Rust/C++ now return `int` instead of `bool` to make
them a bit more FFI compatible portably.
* The `jmp_buf` type has a workaround that will be fixed in the next commit.
* Move setjmp/longjmp to C++
This commit moves the definition of setjmp and longjmp into C++. This is
primarily done because it's [debatable whether it's possible to call
`setjmp` from Rust][rfc]. The semantics of `setjmp` are that it returns
twice but LLVM doesn't actually know about this because rustc isn't
telling LLVM this information, so it's unclear whether it can ever be
safe.
Additionally this removes the need for Rust code to know the definition
of `jmp_buf` which is a pretty hairy type to define in Rust across
platforms.
The solution in this commit is to move all setjmp/longjmp code to C++,
and that way we should be able to guarantee that jumps over wasm JIT
code should always go from C++ to C++, removing Rust from the equation
for now from needing to get any fiddly bits working across platforms.
This should overall help it be a bit more portable and also means Rust
doesn't have to know about `jmp_buf` as a type.
The previous `Vec` of `jmp_buf` is now replaced with one thread-local
pointer where previous values are stored on the stack and restored when
the function returns. This is intended to be functionally the same as
the previous implementation.
[rfc]: https://github.com/rust-lang/rfcs/issues/2625
* rustfmt
* Use volatile loads/stores
* Remove mention of cmake from README
Fix the following warning from Rust 1.35:
warning: cannot borrow `*self` as mutable because it is also borrowed as immutable
--> wasmtime-runtime/src/instance.rs:473:25
|
465 | } else if let Some(start_export) = self.module.exports.get("_start") {
| ----------- immutable borrow occurs here
...
473 | self.invoke_function(*func_index)
| ^^^^ ----------- immutable borrow later used here
| |
| mutable borrow occurs here
|
= note: #[warn(mutable_borrow_reservation_conflict)] on by default
= warning: this borrowing pattern was not meant to be accepted, and may become a hard error in the future
= note: for more information, see issue #59159 <https://github.com/rust-lang/rust/issues/59159>
* Changed `memory_grow` and `memory_index` in `Instance` struct to be `pub(crate)` and added the equivalent proxy methods to the `InstanceHandle` struct.
