Commit Graph

2 Commits

Author SHA1 Message Date
Peter Huene
4ccf0fdfa3 Fix build errors in x86 unwind info when building no_std. (#1214)
This commit fixes the build errors in the unwind info implementation for
the x86 ABI by changing `byteorder` to build `no_std`.

This copies two simple functions from the `WriteBytesExt` trait so that
we can easily write to a `Vec<u8>` with a particular endianness.

Fixes #1203.
2019-11-07 16:41:32 -08:00
Peter Huene
8923bac7e8 Implement emitting Windows unwind information for fastcall functions. (#1155)
* Implement emitting Windows unwind information for fastcall functions.

This commit implements emitting Windows unwind information for x64 fastcall
calling convention functions.

The unwind information can be used to construct a Windows function table at
runtime for JIT'd code, enabling stack walking and unwinding by the operating
system.

* Address code review feedback.

This commit addresses code review feedback:

* Remove unnecessary unsafe code.
* Emit the unwind information always as little endian.
* Fix comments.

A dependency from cranelift-codegen to the byteorder crate was added.
The byteorder crate is a no-dependencies crate with a reasonable
abstraction for writing binary data for a specific endianness.

* Address code review feedback.

* Disable default features for the `byteorder` crate.
* Add a comment regarding the Windows ABI unwind code numerical values.
* Panic if we encounter a Windows function with a prologue greater than 256
  bytes in size.
2019-11-05 13:14:30 -08:00