Integrate jobserver support to parallel codegen
This commit integrates the `jobserver` crate into the compiler. The crate was
previously integrated in to Cargo as part of rust-lang/cargo#4110. The purpose
here is to two-fold:
* Primarily the compiler can cooperate with Cargo on parallelism. When you run
`cargo build -j4` then this'll make sure that the entire build process between
Cargo/rustc won't use more than 4 cores, whereas today you'd get 4 rustc
instances which may all try to spawn lots of threads.
* Secondarily rustc/Cargo can now integrate with a foreign GNU `make` jobserver.
This means that if you call cargo/rustc from `make` or another
jobserver-compatible implementation it'll use foreign parallelism settings
instead of creating new ones locally.
As the number of parallel codegen instances in the compiler continues to grow
over time with the advent of incremental compilation it's expected that this'll
become more of a problem, so this is intended to nip concurrent concerns in the
bud by having all the tools to cooperate!
Note that while rustc has support for itself creating a jobserver it's far more
likely that rustc will always use the jobserver configured by Cargo. Cargo today
will now set a jobserver unconditionally for rustc to use.
mark calls in the unwind path as !noinline
The unwind path is always cold, so that should not have bad performance
implications. This avoids catastrophic exponential inlining, and also
decreases the size of librustc.so by 1.5% (OTOH, the size of `libstd.so`
increased by 0.5% for some reason).
Fixes#41696.
r? @nagisa
This commit integrates the `jobserver` crate into the compiler. The crate was
previously integrated in to Cargo as part of rust-lang/cargo#4110. The purpose
here is to two-fold:
* Primarily the compiler can cooperate with Cargo on parallelism. When you run
`cargo build -j4` then this'll make sure that the entire build process between
Cargo/rustc won't use more than 4 cores, whereas today you'd get 4 rustc
instances which may all try to spawn lots of threads.
* Secondarily rustc/Cargo can now integrate with a foreign GNU `make` jobserver.
This means that if you call cargo/rustc from `make` or another
jobserver-compatible implementation it'll use foreign parallelism settings
instead of creating new ones locally.
As the number of parallel codegen instances in the compiler continues to grow
over time with the advent of incremental compilation it's expected that this'll
become more of a problem, so this is intended to nip concurrent concerns in the
bud by having all the tools to cooperate!
Note that while rustc has support for itself creating a jobserver it's far more
likely that rustc will always use the jobserver configured by Cargo. Cargo today
will now set a jobserver unconditionally for rustc to use.
Memoize types in `is_representable` to avoid exponential worst-case
I could have made representability a cached query, but that would have
been added complexity for not much benefit - outside of the exponential
worst-case, this pass is fast enough already.
Fixes#42747.
r? @eddyb
Remove in-tree flate/getopts crates
Remove `src/libflate` in favor of `flate2` on crates.io and `src/libgetopts` in favor of `getopts` on crates.io. The replacements have slightly different APIs and the usage in the compiler has been updated to reflect this.
This uncovered an unfortunate limitation of the compiler today to deal with linking everything correctly, and the workaround can be found documented in `src/librustc/Cargo.toml`.
Add a Read::initializer method
This is an API that allows types to indicate that they can be passed
buffers of uninitialized memory which can improve performance.
cc @SimonSapin
r? @alexcrichton
Clearer Error Message for Duplicate Definition
Clearer use of the error message and span labels to communicate duplication definitions/imports.
fixes#42061
Convert `Into<Box<[T]>> for Vec<T>` into `From<Vec<T>> for Box<[T]>`
As the `collections` crate has been merged into `alloc` in #42648 this impl is now possible. This is the final part of #42129 missing from #42227.
add `FromStr` Impl for `char`
fixes#24939.
is it possible to use pub(restricted) instead of using a stability attribute for the internal error representation? is it needed at all?
This commit deletes the in-tree `getopts` crate in favor of the crates.io-based
`getopts` crate. The main difference here is with a new builder-style API, but
otherwise everything else remains relatively standard.
The unwind path is always cold, so that should not have bad performance
implications. This avoids catastrophic exponential inlining, and also
decreases the size of librustc.so by 1.5% (OTOH, the size of `libstd.so`
increased by 0.5% for some reason).
Fixes#41696.
A long time coming this commit removes the `flate` crate in favor of the
`flate2` crate on crates.io. The functionality in `flate2` originally flowered
out of `flate` itself and is additionally the namesake for the crate. This will
leave a gap in the naming (there's not `flate` crate), which will likely cause a
particle collapse of some form somewhere.
Enable wasm LLVM backend
Enables compilation to WebAssembly with the LLVM backend using the target triple "wasm32-unknown-unknown". This is the beginning of my work on #38804.
**edit:** The new new target is now wasm32-experimental-emscripten instead of wasm32-unknown-unknown.
Allocator integration
Lets start getting some feedback on `trait Alloc`.
Here is:
* the `trait Alloc` itself,
* the `struct Layout` and `enum AllocErr` that its API relies on
* a `struct HeapAlloc` that exposes the system allocator as an instance of `Alloc`
* an integration of `Alloc` with `RawVec`
* ~~an integration of `Alloc` with `Vec`~~
TODO
* [x] split `fn realloc_in_place` into `grow` and `shrink` variants
* [x] add `# Unsafety` and `# Errors` sections to documentation for all relevant methods
* [x] remove `Vec` integration with `Allocator`
* [x] add `allocate_zeroed` impl to `HeapAllocator`
* [x] remove typedefs e.g. `type Size = usize;`
* [x] impl `trait Error` for all error types in PR
* [x] make `Layout::from_size_align` public
* [x] clarify docs of `fn padding_needed_for`.
* [x] revise `Layout` constructors to ensure that [size+align combination is valid](https://github.com/rust-lang/rust/pull/42313#issuecomment-306845446)
* [x] resolve mismatch re requirements of align on dealloc. See [comment](https://github.com/rust-lang/rust/pull/42313#issuecomment-306202489).
