Fix io::copy specialization using copy_file_range when writer was opened with O_APPEND
fixes#82410
While `sendfile()` returns `EINVAL` when the output was opened with O_APPEND, `copy_file_range()` does not and returns `EBADF` instead, which – unlike other `EBADF` causes – is not fatal for this operation since a regular `write()` will likely succeed.
We now treat `EBADF` as a non-fatal error for `copy_file_range` and fall back to a read-write copy as we already did for several other errors.
Refactor: arrange lints in `methods` module
This PR arranges methods lints so that they can be accessed more easily.
Basically, I refactored them following the instruction described in #6680.
changelog: Move lints in methods module into their own modules.
Enable MemorySSA in MemCpyOpt
LLVM 12 ships with an implementation of MemCpyOpt which is based on MSSA instead of MDA. This implementation can eliminate memcpys across blocks, and as such fixes many (but not all) failures to eliminate redundant memcpys for Rust code. Unfortunately this was only enabled by default shortly after LLVM 12 was cut. This backports the enablement to our LLVM fork.
Perf results: https://perf.rust-lang.org/compare.html?start=8fd946c63a6c3aae9788bd459d278cb2efa77099&end=0628b91ce17035fb5b6a1a99a4f2ab9ab69be7a8
There are improvements on check and debug builds, which indicate that rustc itself has become faster. For opt builds this is, on average, a very minor improvement as well, although there is one significant outlier with deep-vector-opt. This benchmark creates ~140000 zero stores, which are now coalesced into a memset slightly later, resulting in longer compile-time for intermediate passes.
move lintcheck into its own crate
This pr:
* moves lintcheck out of `clippy dev` and into its own crate (`lintcheck`) (I should have done this earlier :D)
* makes lintcheck terminate if it is not launched from the repo root (to prevent problems with wrong paths when using `cargo run` in the crate root)
* fixes json lint messages leaking the runners `$HOME` when a lint messages comes from a proc macro that originates from a crate inside the `$CARGO_CACHE`
* adds more documentation to lintchecks `README.md` and mentions lintcheck in `docs/basics.md`
changelog: none
Eagerly construct bodies of THIR
With this PR:
- the THIR is no longer constructed lazily, but is entirely built before being passed to the MIR Builder
- the THIR is now allocated in arenas instead of `Box`es
However, this PR doesn't make any changes to the way patterns are constructed: they are still boxed, and exhaustiveness checking is unchanged.
Implements MCP rust-lang/compiler-team#409.
Closesrust-lang/project-thir-unsafeck#1.
r? `@ghost` cc `@nikomatsakis` `@oli-obk`
This updates the LLVM submodule to pick up a backported patch
to enable MemorySSA-based MemCpyOpt, which is capable of optimizing
away memcpy's across basic blocks.
This will terminate the program if run via "cargo run".
"cargo run" does currently not work because at least a bunch of paths do not take that into account.
