Only include space in RUSTFLAGS extra flags if not empty
When the RUSTFLAGS_STAGE_{1,2} is not set, including a space means
the string will always be non-empty and RUSTFLAGS will be always be
reset which breaks other ways of setting these such as through config
in CARGO_HOME.
Handle fast-submodules option correctly
This option was introduced in 72cb109bec, but it uses two different
spellings (`fast-submodule` in `bootstrap.py` vs `fast-submodules` in
`config.toml.example`) and isn't handled by Rust bootstrap which means
that any attempt to set this flag fails.
This commit tweaks the tokenization of a doc comment to use `#[doc = "..."]`
like `macro_rules!` does (instead of treating it as a `Literal` token).
Additionally it fixes treatment of negative literals in the compiler, for
exapmle `Literal::i32(-1)`. The current fix is a bit of a hack around the
current compiler implementation, providing a fix at the proc-macro layer rather
than the libsyntax layer.
This should be enough and shouldn't require append(true) since we're not
explicitly writing anything so we're not flushing it so we've no risk of
overwriting it
Implement some trivial size_hints for various iterators
This also implements ExactSizeIterator where applicable.
Addresses most of the Iterator traits mentioned in #23708.
I intend to do more, but I don't want to make the PR too large.
Chosen to start a precedent of using it on ones that are potentially-expensive and where using it for side effects is particularly discouraged.
Discuss :)
optimize NLL constraint propagation a little
Removes a bone-headed hot spot in NLL constant propagation; we were re-allocating the stack vector and hashmap as we repeated the DFS. This change shares those resources across each call.
It also modifies the constraint list to be a linked list; arguably I should revert that, though, as this didn't turn out to be a perf hit and perhaps the old code was clearer? (Still, the new style appeals to me.)
r? @pnkfelix
When the RUSTFLAGS_STAGE_{1,2} is not set, including a space means
the string will always be non-empty and RUSTFLAGS will be always be
reset which breaks other ways of setting these such as through config
in CARGO_HOME.
This option was introduced in 72cb109bec, but it uses two different
spellings (fast-submodule vs fast-submodules) and isn't handled by
Rust bootstrap which means that any attempt to set this flag fails.
Revert "Add TryFrom and TryInto to the prelude"
This reverts commit 09008cc23f.
This addition landed in https://github.com/rust-lang/rust/pull/49305 and turned out to break crates that had their own copy of `TryFrom` in order to use it on the Stable channel :(
We’ll explore the possibility of the 2018 edition having a different prelude that includes this traits. However per the editions RFC this requires implementing a warning in the 2015 edition for code that *would* break.
rustc: Forbid #[inline(always)] with #[target_feature]
Once a target feature is enabled for a function that means that it in general
can't be inlined into other functions which don't have that target feature
enabled. This can cause both safety and LLVM issues if we were to actually
inline it, so `#[inline(always)]` both can't be respected and would be an error
if we did so!
Today LLVM doesn't inline functions with different `#[target_feature]`
annotations, but it turns out that if one is tagged with `#[inline(always)]`
it'll override this and cause scary LLVM error to arise!
This commit fixes this issue by forbidding these two attributes to be used in
conjunction with one another.
Closesrust-lang-nursery/stdsimd#404
This adds a new method to all numeric `Atomic*` types with a
safe compare-and-set loop, so users will no longer need to write
their own, except in *very* strange circumstances.
This solves #48384 with `x.fetch_max(_)`/`x.fetch_min(_)`. It
also relates to #48655 (which I misuse as tracking issue for now).
*note* This *might* need a crater run because the functions could
clash with third party extension traits.
Use f{32,64}::to_bits for is_zero test in vec::SpecFromElem
vec::SpecFromElem provides an optimization to use calloc to fill a Vec
when the element given to fill the Vec is represented by 0.
For floats, the test for that currently used is `x == 0. &&
x.is_sign_positive()`. When compiled in a standalone function, rustc
generates the following assembly:
```
xorps xmm1, xmm1
ucomisd xmm0, xmm1
setnp al
sete cl
and cl, al
movq rax, xmm0
test rax, rax
setns al
and al, cl
ret
```
A simpler test telling us whether the value is represented by 0, is
`x.to_bits() == 0`, which rustc compiles to:
```
movq rax, xmm0
test rax, rax
sete al
ret
```
Not that the test is hot in any way, but it also makes it clearer what
the intent in the rust code is.
