Implement step 1 of rust-lang/rfcs#702
Allows the expression `..` (without either endpoint) in general, can be
used in slicing syntax `&expr[..]` where we previously wrote `&expr[]`.
The old syntax &expr[] is not yet removed or warned for.
In effect, temporary anonymous values created during the evaluation of
ITER_EXPR no longer not live for the entirety of the block surrounding
the for-loop; instead they only live for the extent of the for-loop
itself, and no longer.
----
There is one case I know of that this breaks, demonstrated to me by
niko (but it is also a corner-case that is useless in practice). Here
is that case:
```
fn main() {
let mut foo: Vec<&i8> = Vec::new();
for i in &[1, 2, 3] { foo.push(i) }
}
```
Note that if you add any code following the for-loop above, or even a
semicolon to the end of it, then the code will stop compiling (i.e.,
it gathers a vector of references but the gathered vector cannot
actually be used.)
(The above code, despite being useless, did occur in one run-pass test
by accident; that test is updated here to accommodate the new
striction.)
----
So, technically this is a:
[breaking-change]
(I often run `compiletest` by hand by cut-and-pasting from what `make`
runs, but then I need to tweak it (cut out options) and its useful to
be told when I have removed an option that is actually required, such
as `--android-cross-path=path`.)
This can be considered partial work on #8256.
The main observable change: macro expansion sometimes results in spans
where `lo > hi`; so for now, when we have such a span, do not attempt
to return a snippet result.
(Longer term, we might think about whether we could still present a
snippet for the cases where this arises, e.g. perhaps by showing the
whole macro as the snippet, assuming that is the sole cause of such
spans; or by somehow looking up the closest AST node that holds both
`lo` and `hi`, and showing that.)
As a drive-by, revised the API to return a `Result` rather than an
`Option`, with better information-packed error value that should help
us (and maybe also our users) identify the causes of such problems in
the future. Ideally the call-sites that really want an actual snippet
would be updated to catch the newly added `Err` case and print
something meaningful about it, but that is not part of this PR.
This restructures tidy.py to walk the tree itself,
and improves performance considerably by not loading entire
files into buffers for licenseck.
Splits build rules into 'tidy', 'tidy-basic', 'tidy-binaries',
'tidy-errors', 'tidy-features'.
This is half of what @Aatch implemented in #21418. The non-null assumption is later canonicalized to !nonnull metadata and doesn't cause any slowdowns (in fact the build is slightly faster with this change). I left out the other half of #21418 because that still causes a ~16% increase in compile times (30m -> 35m).
- add `_SC_GETPW_R_SIZE_MAX` constant
- declare `struct passwd`
- convert `load_self` to `current_exe`
Note: OpenBSD don't provide system function to return a valuable Path
for `env::current_exe`. The implementation is currently based on the
value of `argv[0]`, which couldn't be used when executable is called via
PATH.
This needs a snapshot that includes #21805 before it can be merged.
There are some places where type inference regressed after I removed the annotations (see `FIXME`s). cc @nikomatsakis.
r? @eddyb or anyone
(I'll remove the `FIXME`s before merging, as they are only intended to point out regressions)
New functions, slice::from_raw_parts and slice::from_raw_parts_mut,
are added to implement the lifetime convention as agreed in RFC PR #556.
The functions slice::from_raw_buf and slice::from_raw_mut_buf are
left deprecated for the time being.
On OSX the linker has a separate framework lookup path which is specified via
the `-F` flag. This adds a new kind of `-L` path recognized by the compiler for
frameworks to be passed through to the linker.
Closes#20259
