Because the last item needs special handling, it seems that LLVM has trouble canonicalizing the loops in external iteration. With the override, it becomes obvious that the start==end case exits the loop (as opposed to the one *after* that exiting the loop in external iteration).
Fix ref-to-ptr coercions not working with NLL in certain cases
Implicit coercions from references to pointers were lowered to slightly
different Mir than explicit casts (e.g. 'foo as *mut T'). This resulted
in certain uses of self-referential structs compiling correctly when an
explicit cast was used, but not when the implicit coercion was used.
To fix this, this commit adds an outer 'Use' expr when applying a
raw-ptr-borrow adjustment. This makes the lowered Mir for coercions
identical to that of explicit coercions, allowing the original code to
compile regardless of how the raw ptr cast occurs.
Fixes#47722
Cleanup the shim code
- We now write directly to `RETURN_PLACE` instead of creating intermediates
- `tuple_like_shim` takes an iterator (used by #47867)
- `tuple_like_shim` no longer relies on it being the first thing to create blocks, and uses relative block indexing in a cleaner way (necessary for #47867)
- All the shim builders take `dest, src` arguments instead of hardcoding RETURN_PLACE
r? @eddyb
Turn `type_id` into a constant intrinsic
https://github.com/rust-lang/rust/issues/27745
The method `get_type_id` in `Any` is intended to support reflection. It's currently unstable in favor of using an associated constant instead. This PR makes the `type_id` intrinsic a constant intrinsic, the same as `size_of` and `align_of`, allowing `TypeId::of` to be a `const fn`, which will allow using an associated constant in `Any`.
ui tests: diff from old (expected) to new (actual) instead of backwards.
Previously `actual` was "old" and `expected` was "new" which resulted in `+` before `-`.
AFAIK all diff tools put `-` before `+`, which made the previous behavior *very confusing*.
r? @nikomatsakis
Stabilize feature(match_beginning_vert)
With this feature stabilized, match expressions can optionally have a `|` at the beginning of each arm.
Reference PR: rust-lang-nursery/reference#231
Closes#44101
Use a range to identify SIGSEGV in stack guards
Previously, the `guard::init()` and `guard::current()` functions were
returning a `usize` address representing the top of the stack guard,
respectively for the main thread and for spawned threads. The `SIGSEGV`
handler on `unix` targets checked if a fault was within one page below that
address, if so reporting it as a stack overflow.
Now `unix` targets report a `Range<usize>` representing the guard memory,
so it can cover arbitrary guard sizes. Non-`unix` targets which always
return `None` for guards now do so with `Option<!>`, so they don't pay any
overhead.
For `linux-gnu` in particular, the previous guard upper-bound was
`stackaddr + guardsize`, as the protected memory was *inside* the stack.
This was a glibc bug, and starting from 2.27 they are moving the guard
*past* the end of the stack. However, there's no simple way for us to know
where the guard page actually lies, so now we declare it as the whole range
of `stackaddr ± guardsize`, and any fault therein will be called a stack
overflow. This fixes#47863.
decline to lint technically-unnecessary parens in function or method arguments inside of nested macros
In #46980 ("in which the unused-parens lint..." (14982db2d6)), the
unused-parens lint was made to check function and method arguments,
which it previously did not (seemingly due to oversight rather than
willful design). However, in #47775 and discussion thereon,
user–developers of Geal/nom and graphql-rust/juniper reported that the
lint was seemingly erroneously triggering on certain complex macros in
those projects. While this doesn't seem like a bug in the lint in the
particular strict sense that the expanded code would, in fact, contain
unncecessary parentheses, it also doesn't seem like the sort of thing
macro authors should have to think about: the spirit of the
unused-parens lint is to prevent needless clutter in code, not to give
macro authors extra heartache in the handling of token trees.
We propose the expediency of declining to lint unused parentheses in
function or method args inside of nested expansions: we believe that
this should eliminate the petty, troublesome lint warnings reported
in the issue, without forgoing the benefits of the lint in simpler
macros.
It seemed like too much duplicated code for the `Call` and `MethodCall`
match arms to duplicate the nested-macro check in addition to each
having their own `for` loop, so this occasioned a slight refactor so
that the function and method cases could share code—hopefully the
overall intent is at least no less clear to the gentle reader.
This is concerning #47775.
rustc: prefer ParamEnvAnd and LayoutCx over tuples for LayoutOf.
This PR provides `tcx.layout_of(param_env.and(ty))` as the idiomatic replacement for the existing `(tcx, param_env).layout_of(ty)` and removes fragile (coherence-wise) layout-related tuple impls.
r? @nikomatsakis
Dist builds should always be as fast as we can make them, and since
those run on CI we don't care quite as much for the build being somewhat
slower. As such, we don't automatically enable ThinLTO on builds for the
dist builders.
copy_nonoverlapping example: Fixed typo
The comment referred to a variable using an incorrect name. (it has probably been renamed since the comment was written, or the comment was copied elsewhere - I noted the example in libcore has the `tmp` name for the temporary variable.)
Tweak presentation on lifetime trait mismatch
- On trait/impl method discrepancy, add label pointing at trait signature.
- Point only at method definition when referring to named lifetimes on lifetime mismatch.
- When the sub and sup expectations are the same, tweak the output to avoid repeated spans.
Fix#30790, CC #18759.
The comment referred to a variable using an incorrect name. (it has probably been renamed since the comment was written, or the comment was copied elsewhere - I noted the example in libcore has the `tmp` name for the temporary variable.)
