Drive trans from the output of the translation item collector
This PR changes the way how translation works above the item level. Instead of walking the HIR and calling `trans_item()` on everything encountered (while instantiating monomorphizations on-demand), we now just process the list of translation items generated by the `trans::collector`. Using the collector has the benefit of being able to know the exact set of monomorphizations and symbols before actually running translation, something that is crucial for incremental compilation (but also has [other benefits](https://github.com/rust-lang/rust/pull/33602)).
The collector has existed for quite a while now, but so far it's output was only used for running some auto-tests. With this PR it becomes the only source of truth about what gets translated.
One modification we had to make, compared to the initial approach, is that closures are not represented as their own `TransItems`. Doing so, while still supporting non-MIR-based translation, would have been prohibitively complex, and not worth the trouble since legacy-trans will disappear sooner or later. Once there is solely MIR-trans, it would be a good idea to make closures `TransItems` again.
This PR removes the most obvious functions and tables that are not needed anymore, but there's definitely still more cleanup possible later on (e.g. `monomorphize::monomorphic_fn()` does very little at this point). Since there are already more than 10 commits in here, doing this in a separate PR seems to be a better idea.
These changes definitely warrant a crater run.
Thanks @Aatch, for taking on one of the more tedious tasks during the dev-sprint!
Thanks @eddyb, for doing some nice refactorings to symbol name generation and making sure these landed so I could use them!
cc @rust-lang/compiler
cc @rust-lang/tools
The data tracked here was meant to compare the output of the
translation item collector to the set of translation items found
by the on-demand translator.
Functions and method are declared ahead-of-time, including generic ones.
Closures are not considered trans items anymore, instead they are
translated on demands.
Use hints with getaddrinfo() in std::net::lookup_host()
As noted in #24250, `std::net::lookup_host()` repeats each IPv[46] address in the result set. The number of repetitions is OS-dependent; e.g., Linux and FreeBSD give three copies, OpenBSD gives two. Filtering the duplicates can be done by the user if `lookup_host()` is used explicitly, but not with functions like `TcpStream::connect()`. What happens with the latter is that any unsuccessful connection attempt will be repeated as many times as there are duplicates of the address.
The program:
```rust
use std::net::TcpStream;
fn main() {
let _stream = TcpStream::connect("localhost:4444").unwrap();
}
```
results in the following capture:
[capture-before.txt](https://github.com/rust-lang/rust/files/352004/capture-before.txt)
assuming that "localhost" resolves both to ::1 and 127.0.0.1, and that the listening program opens just an IPv4 socket (e.g., `nc -l 127.0.0.1 4444`.) The reason for this behavior is explained in [this comment](https://github.com/rust-lang/rust/issues/24250#issuecomment-92240152): `getaddrinfo()` is not constrained.
Various OSS projects (I checked out Postfix, OpenLDAP, Apache HTTPD and BIND) which use `getaddrinfo()` generally constrain the result set by using a non-NULL `hints` parameter and setting at least `ai_socktype` to `SOCK_STREAM`. `SOCK_DGRAM` would also work. Other parameters are unnecessary for pure name resolution.
The patch in this PR initializes a `hints` struct and passes it to `getaddrinfo()`, which eliminates the duplicates. The same test program as above with this change produces:
[capture-after.txt](https://github.com/rust-lang/rust/files/352042/capture-after.txt)
All `libstd` tests pass with this patch.
enhancewindows documentation in getting-started
- minor pronoun fix We -> You
- PATH troubleshooting
- dir output is vertical (but did not include timestamps)
- executables not in %PATH% require .\
r? @steveklabnik
Correct inline assembly clobber formatting.
Fixes the formatting for inline assembly clobbers used in the book.
As this causes llvm to silently ignore the clobber an error is also
added to catch cases in which the wrong formatting was used.
Additionally a test case is added to confirm that this error works.
This fixes#34458
Note: this is only one out of a few possible ways to fix the issue
depending on how the asm! macro formatting is wanted.
Additionally, it'd be nicer to have some kind of test or feedback
from llvm if the clobber constraints are valid, but I do not know
enough about llvm to say if or how this is possible.
Introducing TokenStreams and TokenSlices for procedural macros
This pull request introduces TokenStreams and TokenSlices into the compiler in preparation for usage as part of RFC 1566 (procedural macros).
r? @nrc
rustbuild: Remove the `build` directory
The organization in rustbuild was a little odd at the moment where the `lib.rs`
was quite small but the binary `main.rs` was much larger. Unfortunately as well
there was a `build/` directory with the implementation of the build system, but
this directory was ignored by GitHub on the file-search prompt which was a
little annoying.
This commit reorganizes rustbuild slightly where all the library files (the
build system) is located directly inside of `src/bootstrap` and all the binaries
now live in `src/bootstrap/bin` (they're small). Hopefully this should allow
GitHub to index and allow navigating all the files while maintaining a
relatively similar layout to the other libraries in `src/`.
When resolving a hostname, pass a hints struct where ai_socktype is
set to SOCK_STREAM in order to eliminate repeated results for each
protocol family.
Add to `resolve`'s public API
This adds a public method `with_module_lexical_scope` to `Resolver` to allow users to resolve a path in the lexical scope of an arbitrary module.
r? @nrc
Fix expansion performance regression
**syntax-[breaking-change] cc #31645**
This fixes#34630 by reverting commit 5bf7970 of PR #33943, which landed in #34424.
By removing the `Rc<_>` wrapping around `Delimited` and `SequenceRepetition` in `TokenTree`, 5bf7970 made cloning `TokenTree`s more expensive. While this had no measurable performance impact on the compiler's crates, it caused an order of magnitude performance regression on some macro-heavy code in the wild. I believe this is due to clones of `TokenTree`s in `macro_parser.rs` and/or `macro_rules.rs`.
r? @nrc
