fs::write: Add example writing a &str
This adds an example to the documentation for `fs::write` that demonstrates the use of the `AsRef<[u8]>` implementation for &str. Experienced users should already recognize the possibility from the type signature, but new users may not recognize the significance.
It's silly for a hot function like `bump()` to have such an expensive
bounds check. This patch replaces terminator with `end_src_index`.
Note that the `self.terminator` check in `is_eof()` wasn't necessary
because of the way `StringReader` is initialized.
- `source_text` becomes `src`, matching `FileMap::src`.
- `byte_offset()` becomes `src_index()`, which makes it clearer that
it's an index into `src`. (Likewise for variables containing
`byte_offset` in their name.) This function also now returns a `usize`
instead of a `BytePos`, because every callsite immediately converted
the `BytePos` to a `usize`.
This patch removes the "old"/"new" names in favour of "foo"/"next_foo",
which matches the field names.
It also moves the setting of `self.{ch,pos,next_pos}` in the common case
to the end, so that the meaning of "foo"/"next_foo" is consistent until
the end.
rustc: leave space for fields of uninhabited types to allow partial initialization.
Fixes#49298 by only collapsing uninhabited enum variants, and only if they only have ZST fields.
Fixes#50442 incidentally (@nox's optimization didn't take into account uninhabited variants).
Don't require clippy/miri for beta
r? @kennytm
cc @alexcrichton
I'm trying this out locally atm to see if it works as I think it should. Not sure how to test it for real except wait for the next beta.
fixes#50557
Better error reporting in Copy derive
In Copy derive, report all fulfillment erros when present and do not report errors for types tainted with `TyErr`. Also report all fields which are not Copy rather than just the first.
Also refactored `fn fully_normalize`, removing the not very useful helper function along with a FIXME to the closed issue #26721 that looks out of context now.
Fixes#50480
r? @estebank
A high impact bug because a lot of common traits use a `Self`
substitution by default. Should be backported to beta.
There was a check for this which wasn't catching all cases, it was made
more robust.
Fixes#49376Fixes#50626
r? @petrochenkov
Rollup of 13 pull requests
Successful merges:
- #50544 (Cleanup some dependencies)
- #50545 (Made some functions in time module const)
- #50550 (use fmt::Result where applicable)
- #50558 (Remove all reference to DepGraph::work_products)
- #50602 (Update canonicalize docs)
- #50607 (Allocate Symbol strings from an arena)
- #50613 (Migrate the toolstate update bot to rust-highfive)
- #50624 (fs::write: Add example writing a &str)
- #50634 (Do not silently truncate offsets for `read_at`/`write_at` on emscripten)
- #50644 (AppVeyor: Read back trace from crash dump on failure.)
- #50661 (Ignore non .rs files for tidy libcoretest)
- #50663 (rustc: Allow an edition's feature on that edition)
- #50667 (rustc: Only suggest deleting `extern crate` if it works)
Failed merges:
In Copy derive, report all fulfillment erros when present and do not
report errors for types tainted with `TyErr`. Also report all fields
which are not Copy rather than just the first.
Also refactored `fn fully_normalize`, removing the not very useful
helper function along with a FIXME to the closed issue #26721 that's
looks out of context now.
Set PrepareForThinLTO flag when using ThinLTO
The LLVM PassManager has a PrepareForThinLTO flag, which is intended for use when compilation occurs in conjunction with linking by ThinLTO. The flag has two effects:
* The NameAnonGlobal pass is run after all other passes, which ensures that all globals have a name.
* In optimized builds, a number of late passes (mainly related to vectorization and unrolling) are disabled, on the rationale that these a) will increase codesize of the intermediate artifacts and b) will be run by ThinLTO again anyway.
This patch enables the use of PrepareForThinLTO if Thin or ThinLocal linking is used.
The background for this change is the CI failure in #49479, which we assume to be caused by the NameAnonGlobal pass not being run. As this changes which passes LLVM runs, this might have performance (or other) impact, so we want to land this separately.
This commit updates one of the edition lints to only suggest deleting `extern
crate` if it actually works. Otherwise this can yield some confusing behavior
with rustfix specifically where if you accidentally deny the `rust_2018_idioms`
lint in the 2015 edition it's suggesting features that don't work!
This commit fixes a hard error where the `#![feature(rust_2018_preview)]`
feature was forbidden to be mentioned when the `--edition 2018` flag was passed.
This instead silently accepts that feature gate despite it not being necessary.
It's intended that this will help ease the transition into the 2018 edition as
users will, for the time being, start off with the `rust_2018_preview` feature
and no longer immediately need to remove it.
Closes#50662
Update canonicalize docs
I was recently working with file-paths in Rust, and I felt let down by the `std::fs::canonicalize` docs, so I figured I should submit a PR with some suggestions.
I was looking for a method to turn a relative path into an absolute path. The `canonicalize` docs didn't mention the words "relative" or "absolute", but they did mention resolving symlinks (which is a kind of canonicalisation and does not imply converting to absolute), so I assumed that's all it did. To remedy this, I've added the word "absolute" to the description of both `std::fs::canonicalize` and `std::path::Path::canonicalize`.
After calling `canonicalize` on Windows, I ran into a bunch of other problems I would not have expected from the function's behaviour on Linux. Specifically, if you call `canonicalize` on a path:
- it's allowed to be much longer than it otherwise would
- `.join("a/slash/delimited/path")` gives you a broken path that Windows can't use, where the same operation would have worked perfectly without `canonicalize` (if the path were short enough)
- the resulting path may confuse other Windows programs if you pass it to them on the command-line, or write it to a config file that they read, etc.
...so I tried to summarize those behaviours too.
If I understand correctly, those behaviours are a side-effect of calling `GetFinalPathNameByHandle`, and the documentation says `canonicalize` might not call that function in future, so maybe those side-effects shouldn't be part of the function's documentation. However, I bet there's a lot of applications deliberately calling `canonicalize` just for the path-length-extension alone, so that particular side-effect is de-facto part of the `canonicalize` interface.
Remove all reference to DepGraph::work_products
This is an attempt at fixing #50500. It will remove the `work_products` key from `DepGraphData` completely, in favour of just passing the relevant data around. I went in a little blindly; everything appears to work just fine but I'd appreciate any additional advice people.
I didn't want to remove too much of what was already there, so I kept the structure pretty much the same (aside from some naming tweaks) - if anyone has suggestions on how to streamline it a little better, happy to follow up.
r? @michaelwoerister
The LLVM PassManager has a PrepareForThinLTO flag, which is intended
when compilation occurs in conjunction with linking by ThinLTO. The
flag has two effects:
* The NameAnonGlobal pass is run after all other passes, which
ensures that all globals have a name.
* In optimized builds, a number of late passes (mainly related to
vectorization and unrolling) are disabled, on the rationale that
these a) will increase codesize of the intermediate artifacts
and b) will be run by ThinLTO again anyway.
This patch enables the use of PrepareForThinLTO if Thin or ThinLocal
linking is used.
The background for this change is the CI failure in #49479, which
we assume to be caused by the NameAnonGlobal pass not being run.
As this changes which passes LLVM runs, this might have performance
(or other) impact, so we want to land this separately.
Don't allocate when creating an empty BTree
Following the discussion in #50266, this adds a static instance of `LeafNode` that empty BTrees point to, and then replaces it on `insert`, `append`, and `entry`. This avoids allocating for empty maps.
Fixes#50266
r? @Gankro
