This clarifies why FP-units are disabled on UEFI targets, as well as
why we must opt into the NXCOMPAT feature.
I did find some time to investigate why GRUB and friends disable FP on
UEFI. The specification explicitly allows using MMX/SSE/AVX, but as it
turns out it does not mandate enabling the instruction sets explicitly.
Hence, any use of these instructions will trigger CPU exceptions,
unless an application explicitly enables them (which is not an option,
as these are global flags that better be controlled by the
kernel/firmware).
Furthermore, UEFI systems are allowed to mark any non-code page as
non-executable. Hence, we must make sure to never place code on the
stack or heap. So we better pass /NXCOMPAT to the linker for it to
complain if it ever places code in non-code pages.
Lastly, this fixes some typos in related comments.
Fixes rustdoc in stage 0, stage 1
When a request for rustdoc is passed for stage 0, x.py build --stage 0
src/tools/rustdoc or ensure(tool::Rustdoc { .. }) with top_stage = 0, we
return the rustdoc for that compiler (i.e., the beta rustdoc).
This fixes stage 0 of https://github.com/rust-lang/rust/issues/52186 as well as being part of general workflow improvements (making stage 0 testing for std work) for rustbuild.
The stage 1 fix (second commit) completely resolves the problem, so this fixes https://github.com/rust-lang/rust/issues/52186.
SGX target: simplify usercall internals
This moves logic from assembly to Rust and removes the special case for exit/panic handling, merging it with regular usercall handling.
Also, this fixes a bug in the exit usercall introduced in a75ae00. The bug would make regular exits look like panics with high probability. It would also with some probability leak information through uncleared registers.
cc @VardhanThigle
r? @alexcrichton
use Ubuntu keyserver for CloudABI ports
The Ubuntu keyserver is more reliable than the MIT PGP server, which is
prone to going down. This commit also explicitly uses port 80 on the
keyserver for reasons outlined in #57844.
Rename rustc_errors dependency in rust 2018 crates
I think this is a better solution than `use rustc_errors as errors` in `lib.rs` and `use crate::errors` in modules.
Related: rust-lang/cargo#5653
cc #58099
r? @Centril
fix str mutating through a ptr derived from &self
Found by Miri: In `get_unchecked_mut` (also used by the checked variants internally) uses `str::as_ptr` to create a mutable reference, but `as_ptr` takes `&self`. This means the mutable references we return here got created from a shared reference, which violates the shared-references-are-read-only discipline!
For this by using a newly introduced `as_mut_ptr` instead.
Cleanup: rename node_id_to_type(_opt)
Renames `node_id_to_type(_opt)` to `hir_id_to_type(_opt)`; this makes it clear we are dealing with HIR nodes and their IDs here.
In addition, a drive-by commit removing `ty::item_path::hir_path_str` (as requested by @eddyb).
Speed up the fast path for assert_eq! and assert_ne!
Currently, the panic!() calls directly borrow the value bindings. This
causes those bindings to always be initialized, i.e. they're initialized
even before the values are even compared. This causes noticeable
overhead in what should be a really cheap operation.
By performing a reborrow of the value in the call to panic!(), we allow
LLVM to optimize that code, so that the extra borrow only happens in the
error case.
We could achieve the same result by dereferencing the values passed to
panic!(), as the format machinery borrows them anyway, but this causes
assertions to fail to compile if one of the values is unsized, i.e. it
would be a breaking change.
