This commit begins the implementation work for RFC 2945. For more
information, see the rendered RFC [1] and tracking issue [2].
A boolean `unwind` payload is added to the `C`, `System`, `Stdcall`,
and `Thiscall` variants, marking whether unwinding across FFI
boundaries is acceptable. The cases where each of these variants'
`unwind` member is true correspond with the `C-unwind`,
`system-unwind`, `stdcall-unwind`, and `thiscall-unwind` ABI strings
introduced in RFC 2945 [3].
### Feature Gate and Unstable Book
This commit adds a `c_unwind` feature gate for the new ABI strings.
Tests for this feature gate are included in `src/test/ui/c-unwind/`,
which ensure that this feature gate works correctly for each of the
new ABIs.
A new language features entry in the unstable book is added as well.
### Further Work To Be Done
This commit does not proceed to implement the new unwinding ABIs,
and is intentionally scoped specifically to *defining* the ABIs and
their feature flag.
### One Note on Test Churn
This will lead to some test churn, in re-blessing hash tests, as the
deleted comment in `src/librustc_target/spec/abi.rs` mentioned,
because we can no longer guarantee the ordering of the `Abi`
variants.
While this is a downside, this decision was made bearing in mind
that RFC 2945 states the following, in the "Other `unwind` Strings"
section [3]:
> More unwind variants of existing ABI strings may be introduced,
> with the same semantics, without an additional RFC.
Adding a new variant for each of these cases, rather than specifying
a payload for a given ABI, would quickly become untenable, and make
working with the `Abi` enum prone to mistakes.
This approach encodes the unwinding information *into* a given ABI,
to account for the future possibility of other `-unwind` ABI
strings.
### Ignore Directives
`ignore-*` directives are used in two of our `*-unwind` ABI test
cases.
Specifically, the `stdcall-unwind` and `thiscall-unwind` test cases
ignore architectures that do not support `stdcall` and
`thiscall`, respectively.
These directives are cribbed from
`src/test/ui/c-variadic/variadic-ffi-1.rs` for `stdcall`, and
`src/test/ui/extern/extern-thiscall.rs` for `thiscall`.
Hugues de Valon [Sun, 24 Jan 2021 17:15:05 +0000 (17:15 +0000)]
Add a new ABI to support cmse_nonsecure_call
This commit adds a new ABI to be selected via `extern
"C-cmse-nonsecure-call"` on function pointers in order for the compiler to
apply the corresponding cmse_nonsecure_call callsite attribute.
For Armv8-M targets supporting TrustZone-M, this will perform a
non-secure function call by saving, clearing and calling a non-secure
function pointer using the BLXNS instruction.
See the page on the unstable book for details.
Signed-off-by: Hugues de Valon <hugues.devalon@arm.com>
Jonas Schievink [Mon, 1 Feb 2021 13:29:47 +0000 (14:29 +0100)]
Rollup merge of #81618 - bjorn3:sync_cg_clif-2021-02-01, r=bjorn3
Sync rustc_codegen_cranelift
The highlight of this sync are abi compatibility with cg_llvm allowing mixing of cg_clif and cg_llvm compiled crates and switching to the x64 cranelift backend based on the new backend framework.
Tyson Nottingham [Mon, 25 Jan 2021 20:56:21 +0000 (12:56 -0800)]
Indicate both start and end of pass RSS in time-passes output
Previously, only the end of pass RSS was indicated. This could easily
lead one to believe that the change in RSS from one pass to the next was
attributable to the second pass, when in fact it occurred between the
end of the first pass and the start of the second.
bors [Wed, 9 Dec 2020 19:53:23 +0000 (19:53 +0000)]
Auto merge of #77611 - oli-obk:atomic_miri_leakage, r=nagisa
Directly use raw pointers in `AtomicPtr` store/load
I was unable to find any reason for this limitation in the latest source of LLVM or in the documentation [here](http://llvm.org/docs/Atomics.html#libcalls-atomic).
bors [Wed, 25 Nov 2020 07:25:19 +0000 (07:25 +0000)]
Auto merge of #79336 - camelid:rename-feature-oibit-to-auto, r=oli-obk
Rename `optin_builtin_traits` to `auto_traits`
They were originally called "opt-in, built-in traits" (OIBITs), but
people realized that the name was too confusing and a mouthful, and so
they were renamed to just "auto traits". The feature flag's name wasn't
updated, though, so that's what this PR does.
There are some other spots in the compiler that still refer to OIBITs,
but I don't think changing those now is worth it since they are internal
and not particularly relevant to this PR.
Also see <https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/opt-in.2C.20built-in.20traits.20(auto.20traits).20feature.20name>.
r? `@oli-obk` (feel free to re-assign if you're not the right reviewer for this)
Camelid [Mon, 23 Nov 2020 03:54:31 +0000 (19:54 -0800)]
Rename `optin_builtin_traits` to `auto_traits`
They were originally called "opt-in, built-in traits" (OIBITs), but
people realized that the name was too confusing and a mouthful, and so
they were renamed to just "auto traits". The feature flag's name wasn't
updated, though, so that's what this PR does.
There are some other spots in the compiler that still refer to OIBITs,
but I don't think changing those now is worth it since they are internal
and not particularly relevant to this PR.
Also see <https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/opt-in.2C.20built-in.20traits.20(auto.20traits).20feature.20name>.
Nicholas-Baron [Fri, 6 Nov 2020 21:24:55 +0000 (13:24 -0800)]
Changed unwrap_or to unwrap_or_else in some places.
The discussion seems to have resolved that this lint is a bit "noisy" in
that applying it in all places would result in a reduction in
readability.
A few of the trivial functions (like `Path::new`) are fine to leave
outside of closures.
The general rule seems to be that anything that is obviously an
allocation (`Box`, `Vec`, `vec![]`) should be in a closure, even if it
is a 0-sized allocation.
Dylan DPC [Mon, 9 Nov 2020 00:13:42 +0000 (01:13 +0100)]
Rollup merge of #78674 - tmiasko:inline-substs-for-mir-body, r=oli-obk
inliner: Use substs_for_mir_body
Changes from 68965 extended the kind of instances that are being
inlined. For some of those, the `instance_mir` returns a MIR body that
is already expressed in terms of the types found in substitution array,
and doesn't need further substitution.
Use `substs_for_mir_body` to take that into account.
Collapse all uses of `target.options.foo` into `target.foo`
with an eye on merging `TargetOptions` into `Target`.
`TargetOptions` as a separate structure is mostly an implementation detail of `Target` construction, all its fields logically belong to `Target` and available from `Target` through `Deref` impls.
Tomasz Miąsko [Fri, 6 Nov 2020 00:00:00 +0000 (00:00 +0000)]
inliner: Use substs_for_mir_body
Changes from 68965 extended the kind of instances that are being
inlined. For some of those, the `instance_mir` returns a MIR body that
is already expressed in terms of the types found in substitution array,
and doesn't need further substitution.
Use `substs_for_mir_body` to take that into account.
Also allow returning PassMode::ByValPair directly into an ssa var
Benchmark #1: ./raytracer_cg_clif_pre
Time (mean ± σ): 8.251 s ± 0.021 s [User: 8.245 s, System: 0.005 s]
Range (min … max): 8.225 s … 8.292 s 10 runs
Benchmark #2: ./raytracer_cg_clif_post
Time (mean ± σ): 8.206 s ± 0.043 s [User: 8.199 s, System: 0.007 s]
Range (min … max): 8.168 s … 8.279 s 10 runs