dist-powerpc-linux: use a pure 32-bit CPU profile
With `-mcpu=power4`, code might use instructions like `fcfid`, excluding
older CPUs like the PowerPC G4, which apparently some users would like
to use. The generic `-mcpu=powerpc` should stick to pure 32-bit PowerPC
instructions.
Fixesrust-lang/cargo#3852.
Re-enable appveyor cache
After breaking the queue last time, I'm cautiously back with a PR to re-enable caching on appveyor.
If you look at https://ci.appveyor.com/project/rust-lang/rust/build/1.0.2623/job/46o90by4ari6gege (one of the multiple runs that started failed, there are actually two errors - one for restoring the cache, one right at the bottom for creating a directory. I only noticed the restore error at the time as I was a bit rushed to revert and didn't stop to wonder why it continued - turns out appveyor [does not abort on cache restore failure](https://github.com/appveyor/ci/issues/723).
Turns out the cause of the build failures was the cache directory existing and me being thinking that because mkdir on windows is [recursive by default](http://stackoverflow.com/a/905239/2352259), it ignores the error if the directory already exists. Apparently this is not true, so now it checks if the directory exists before attempting to create.
In addition, I've added some more paranoia to double check everything is sane.
cstore: return an immutable borrow from `visible_parent_map`
This prevents an ICE when `visible_parent_map` is called multiple times, for example when an item referenced in an impl signature is imported from an `extern crate` statement occurs within an impl.
Fixes#41053.
r? @eddyb
Handle DefPath hashing centrally as part of DefPathTable (+ save work during SVH calculation)
In almost all cases where we construct a `DefPath`, we just hash it and throw it away again immediately.
With this PR, the compiler will immediately compute and store the hash for each `DefPath` as it is allocated. This way we
+ can get rid of any subsequent `DefPath` hash caching (e.g. the `DefPathHashes`),
+ don't need to allocate a transient `Vec` for holding the `DefPath` (although I'm always surprised how little these small, dynamic allocations seem to hurt performance), and
+ we don't hash `DefPath` prefixes over and over again.
That last part is because we construct the hash for `prefix::foo` by hashing `(hash(prefix), foo)` instead of hashing every component of prefix.
The last commit of this PR is pretty neat, I think:
```
The SVH (Strict Version Hash) of a crate is currently computed
by hashing the ICHes (Incremental Computation Hashes) of the
crate's HIR. This is fine, expect that for incr. comp. we compute
two ICH values for each HIR item, one for the complete item and
one that just includes the item's interface. The two hashes are
are needed for dependency tracking but if we are compiling
non-incrementally and just need the ICH values for the SVH,
one of them is enough, giving us the opportunity to save some
work in this case.
```
r? @nikomatsakis
This PR depends on https://github.com/rust-lang/rust/pull/40878 to be merged first (you can ignore the first commit for reviewing, that's just https://github.com/rust-lang/rust/pull/40878).
Only use cargo-vendor if building from git sources
The only time we need to vendor sources is when building from git. If one is
building from a rustc source tarball, everything should already be in place.
This also matters for distros which do offline builds, as they can't install
cargo-vendor this way.
This adds a common `Build::src_is_git` flag, and then uses it in the dist-src
target to decide whether to install or use `cargo-vendor` at all.
Fixes#41042.
The SVH (Strict Version Hash) of a crate is currently computed
by hashing the ICHes (Incremental Computation Hashes) of the
crate's HIR. This is fine, expect that for incr. comp. we compute
two ICH values for each HIR item, one for the complete item and
one that just includes the item's interface. The two hashes are
are needed for dependency tracking but if we are compiling
non-incrementally and just need the ICH values for the SVH,
one of them is enough, giving us the opportunity to save some
work in this case.
On demandify reachability
cc https://github.com/rust-lang/rust/issues/40746
I tried following this guidance from #40746:
> The following tasks currently execute before a tcx is built, but they could be easily converted into queries that are requested after tcx is built. The main reason they are the way they are was to avoid a gratuitious refcell (but using the refcell map seems fine)...
but the result of moving `region_maps` out of `TyCtxt` and into a query caused a lot of churn, and seems like it could potentially result in a rather large performance hit, since it means a dep-graph lookup on every use of `region_maps` (rather than just a field access). Possibly `TyCtxt` could store a `RefCell<Option<RegionMap>>` internally and use that to prevent repeat lookups, but that feels like it's duplicating the work of the dep-graph. @nikomatsakis What did you have in mind for this?
#[used] attribute
(For an explanation of what this feature does, read the commit message)
I'd like to propose landing this as an experimental feature (experimental as in:
no clear stabilization path -- like `asm!`, `#[linkage]`) as it's low
maintenance (I think) and relevant to the "Usage in resource-constrained
environments" exploration area.
The main use case I see is running code before `main`. This could be used, for
instance, to cheaply initialize an allocator before `main` where the alternative
is to use `lazy_static` to initialize the allocator on its first use which it's
more expensive (atomics) and doesn't work on ARM Cortex-M0 microcontrollers (no
`AtomicUsize` on that platform)
Here's a `std` example of that:
``` rust
unsafe extern "C" fn before_main_1() {
println!("Hello");
}
unsafe extern "C" fn before_main_2() {
println!("World");
}
#[link_section = ".init_arary"]
#[used]
static INIT_ARRAY: [unsafe extern "C" fn(); 2] = [before_main_1, before_main_2];
fn main() {
println!("Goodbye");
}
```
```
$ rustc -C lto -C opt-level=3 before_main.rs
$ ./before_main
Hello
World
Goodbye
```
In general, this pattern could be used to let *dependencies* run code before
`main` (which sounds like it could go very wrong in some cases). There are
probably other use cases; I hope that the people I have cc-ed can comment on
those.
Note that I'm personally unsure if the above pattern is something we want to
promote / allow and that's why I'm proposing this feature as experimental. If
this leads to more footguns than benefits then we can just axe the feature.
cc @nikomatsakis ^ I know you have some thoughts on having a process for
experimental features though I'm fine with writing an RFC before landing this.
- `dead_code` lint will have to be updated to special case `#[used]` symbols.
- Should we extend `#[used]` to work on non-generic functions?
cc rust-lang/rfcs#1002
cc rust-lang/rfcs#1459
cc @dpc @JinShil
Avoid type-checking addition and indexing twice.
Fixes#40610 by moving the common `check_expr_coercable_to_type` call before the error reporting logic for binops and removing the one from `check_str_addition`.
Fixes#40861 by removing an unnecessary `check_expr_coercable_to_type` call.
rustdoc: Use pulldown-cmark for Markdown HTML rendering
Instead of rendering all of the HTML in rustdoc this relies on
pulldown-cmark's `push_html` to do most of the work. A few iterator
adapters are used to make rustdoc specific modifications to the output.
This also fixes MarkdownHtml and link titles in plain_summary_line.
https://ollie27.github.io/rust_doc_test/ is the docs built with this change and #41111.
Part of #40912.
cc @GuillaumeGomez
r? @steveklabnik
Fix Markdown issues in the docs
* Since the switch to pulldown-cmark reference links need a blank line
before the URLs. (#40912)
* Reference link references are not case sensitive.
* Doc comments need to be indented uniformly otherwise rustdoc gets
confused.
don't try to blame tuple fields for immutability
Tuple fields don't have an `&T` in their declaration that can be changed
to `&mut T` - skip them..
Fixes#41104.
r? @nikomatsakis
Introduce HashStable trait and base ICH implementations on it.
This PR introduces the `HashStable` trait which marks that a type can be hashed in a way that is stable across multiple compilation sessions. The PR also moves HIR incr. comp. hashing over to implementations of this trait instead of doing this via a HIR visitor. It also provides many `HashStable` implementations that are not used yet (e.g. for MIR types) but soon will be used when we directly hash crate metadata for incr. comp.
I've only done superficial performance measurements but it looks like the new implementation is a bit faster than the current one (due, I suppose, to some bugs I fixed and some unnecessary inefficiencies I removed). Here is the time in seconds for the `compute_incremental_hashes_map` pass for various crates:
| | OLD | NEW |
|:---------------:|:-----:|:-----:|
| libcore | 0.507 | 0.409 |
| libsyntax | 0.320 | 0.260 |
| librustc | 0.730 | 0.611 |
| librustc_driver | 0.024 | 0.015 |
Some notes regarding the implementation:
* Most `HashStable` implementations are provided via the `impl_hash_stable_for!` macro (as suggested by @nikomatsakis). This works out quite well. A custom_derive would have been better but Macros 1.1 are not available in the compiler.
* The trait implementation take care to exhaustively destructure everything they hash so that fields added in the future don't fall through the cracks. This is a bit verbose but I think it's well worth the trouble since we've had quite a few issues with missing fields or visitor callbacks in this area in the past. Most of it is behind the macro anyway.
cc @rust-lang/compiler
r? @nikomatsakis
Instead of rendering all of the HTML in rustdoc this relies on
pulldown-cmark's `push_html` to do most of the work. A few iterator
adapters are used to make rustdoc specific modifications to the output.
This also fixes MarkdownHtml and link titles in plain_summary_line.
* Since the switch to pulldown-cmark reference links need a blank line
before the URLs.
* Reference link references are not case sensitive.
* Doc comments need to be indented uniformly otherwise rustdoc gets
confused.
std: Use `poll` instead of `select`
This gives us the benefit of supporting file descriptors over the limit that
select supports, which...
Closes#40894
Move libXtest into libX/tests
This change moves:
1. `libcoretest` into `libcore/tests`
2. `libcollectionstest` into `libcollections/tests`
This is a follow-up to #39561.
r? @alexcrichton
Handle symlinks in src/bootstrap/clean.rs (mostly) -- resolves#40860.
In response to #40860
The broken condition can be replicated with:
```shell
export MYARCH=x86_64-apple-darwin && mkdir -p build/$MYARCH/subdir &&
touch build/$MYARCH/subdir/file && ln -s build/$MYARCH/subdir/file
build/$MYARCH/subdir/symlink
```
`src/bootstrap/clean.rs` has a custom implementation of removing a tree
`fn rm_rf` that used `std::path::Path::{is_file, is_dir, exists}` while
recursively deleting directories and files. Unfortunately, `Path`'s
implementation of `is_file()` and `is_dir()` and `exists()` always
unconditionally follow symlinks, which is the exact opposite of standard
implementations of deleting file trees.
It appears that this custom implementation is being used to workaround a
behavior in Windows where the files often get marked as read-only, which
prevents us from simply using something nice and simple like
`std::fs::remove_dir_all`, which properly deletes links instead of
following them.
So it looks like the fix is to use `.symlink_metadata()` to figure out
whether tree items are files/symlinks/directories. The one corner case
this won't cover is if there is a broken symlink in the "root"
`build/$MYARCH` directory, because those initial entries are run through
`Path::canonicalize()`, which panics with broken symlinks. So lets just
never use symlinks in that one directory. :-)
Overhaul Bootstrap (x.py) Command-Line-Parsing & Help Output
While working on #40417, I got frustrated with the behavior of x.py and the bootstrap binary it wraps, so I decided to do something about it. This PR should improve documentation, make the command-line-parsing more flexible, and clean up some of the internals. No command that worked before should stop working. At least that's the theory. :-)
This should resolve at least #40920 and #38373.
Changes:
- No more manual args manipulation -- getopts used everywhere except the one place it's not possible. As a result, options can be in any position, now, even before the subcommand.
- The additional options for test, bench, and dist now appear in the help output.
- No more single-letter variable bindings used internally for large scopes.
- Don't output the time measurement when just invoking `x.py` or explicitly passing `-h` or `--help`
- Logic is now much more linear. We build strings up, and then print them.
- Refer to subcommands as subcommands everywhere (some places we were saying "command")
- Other minor stuff.
@alexcrichton This is my first PR. Do I need to do something specific to request reviewers or anything?
Emit proper lifetime start intrinsics for personality slots
We currently only emit a single call to the lifetime start intrinsic
for the personality slot alloca. This happens because we create that
call at the time that we create the alloca, instead of creating it each
time we start using it. Because LLVM usually removes the alloca before
the lifetime intrinsics are even considered, this didn't cause any
problems yet, but we should fix this anyway.
Make 'overlapping_inherent_impls' lint a hard error
This is ought to be implemented in PR #40728. Unfortunately, when I rebased the PR to resolve merge conflict, the "hard error" code disappeared. This PR complements the initial PR.
Now the following rust code gives the following error:
```rust
struct Foo;
impl Foo {
fn id() {}
}
impl Foo {
fn id() {}
}
fn main() {}
```
```
error[E0592]: duplicate definitions with name `id`
--> /home/topecongiro/test.rs:4:5
|
4 | fn id() {}
| ^^^^^^^^^^ duplicate definitions for `id`
...
8 | fn id() {}
| ---------- other definition for `id`
error: aborting due to previous error
```
Let .rev()'s find use the underlying rfind and vice versa
- Connect the plumbing in an obvious way from Rev's find → underlying rfind and vice versa
- A style change in the provided implementation for Iterator::rfind, using simple next_back when it is enough
