Namely: labels, type parameters, bindings in patterns, parameter names in functions without body.
All of these do not need hygiene after lowering to HIR, only span locations.
This is gated on edition 2018 & the `async_await` feature gate.
The parser will accept `async fn` and `async unsafe fn` as fn
items. Along the same lines as `const fn`, only `async unsafe fn`
is permitted, not `unsafe async fn`.The parser will not accept
`async` functions as trait methods.
To do a little code clean up, four fields of the function type
struct have been merged into the new `FnHeader` struct: constness,
asyncness, unsafety, and ABI.
Also, a small bug in HIR printing is fixed: it previously printed
`const unsafe fn` as `unsafe const fn`, which is grammatically
incorrect.
Don’t mention `#[default_lib_allocator]` (which is an implementation detail
irrelevant to most users) and instead suggest using `#[global_allocator]`,
which is often the correct fix.
Add existential type definitions
Note: this does not allow creating named existential types, it just desugars `impl Trait` to a less (but still very) hacky version of actual `existential type` items.
r? @nikomatsakis
Remove attribute_cache from CrateMetadata
This PR will fix#50508 by removing the `attribute_cache` from the `CrateMetadata` struct. Seeing as performance was referenced in the original issue, I also cleaned up a `self.entry(node_id);` call which might have occasionally happened redundantly.
r? @michaelwoerister
Make CrateNum allocation more thread-safe.
This PR makes sure that we can't have race conditions when assigning CrateNums. It's a slight improvement but a larger refactoring of the CrateStore/CrateLoader infrastructure would be good, I think.
r? @Zoxc
Fix ICE #48984
* ~~fbf6423 The tail type was not normalized.~~
* d0839d5680 The method had a wrong assumption that something whose parent is a trait is an associated item. Fixes#48984.
Use sort_by_cached_key where appropriate
A follow-up to https://github.com/rust-lang/rust/pull/48639, converting various slice sorting calls to `sort_by_cached_key` when the key functions are more expensive.
Introduce a TargetTriple enum to support absolute target paths
This PR replaces target triple strings with a `TargetTriple` enum, which represents either a target triple or a path to a JSON target file. The path variant is used if the `--target` argument has a `.json` extension, else the target triple variant is used.
The motivation of this PR is support for absolute target paths to avoid the need for setting the `RUST_TARGET_PATH` environment variable (see rust-lang/cargo#4905 for more information). For places where some kind of triple is needed (e.g. in the sysroot folder), we use the file name (without extension).
For compatibility, we keep the old behavior of searching for a file named `$(target_triple).json` in `RUST_TARGET_PATH` for non-official target triples.
Add basic PGO support.
This PR adds two mutually exclusive options for profile usage and generation using LLVM's instruction profile generation (the same as clang uses), `-C pgo-use` and `-C pgo-gen`.
See each commit for details.
Stabilize the copy_closures and clone_closures features
In addition to the `Fn*` family of traits, closures now implement `Copy` (and similarly `Clone`) if all of the captures do.
Tracking issue: https://github.com/rust-lang/rust/issues/44490
Fix DefKey lookup for proc-macro crates.
Add a special case for proc-macro crates for `def_key()` in the metadata decoder (like we already have for many other methods in there). In the long run, it would be preferable to get rid of the need for special casing proc-macro crates (see #49271).
Fixes https://github.com/rust-lang/rust/issues/48739 (though I wasn't able to come up with a regression test, unfortunately)
r? @eddyb
This commit adds a new attribute to the Rust compiler specific to the wasm
target (and no other targets). The `#[wasm_import_module]` attribute is used to
specify the module that a name is imported from, and is used like so:
#[wasm_import_module = "./foo.js"]
extern {
fn some_js_function();
}
Here the import of the symbol `some_js_function` is tagged with the `./foo.js`
module in the wasm output file. Wasm-the-format includes two fields on all
imports, a module and a field. The field is the symbol name (`some_js_function`
above) and the module has historically unconditionally been `"env"`. I'm not
sure if this `"env"` convention has asm.js or LLVM roots, but regardless we'd
like the ability to configure it!
The proposed ES module integration with wasm (aka a wasm module is "just another
ES module") requires that the import module of wasm imports is interpreted as an
ES module import, meaning that you'll need to encode paths, NPM packages, etc.
As a result, we'll need this to be something other than `"env"`!
Unfortunately neither our version of LLVM nor LLD supports custom import modules
(aka anything not `"env"`). My hope is that by the time LLVM 7 is released both
will have support, but in the meantime this commit adds some primitive
encoding/decoding of wasm files to the compiler. This way rustc postprocesses
the wasm module that LLVM emits to ensure it's got all the imports we'd like to
have in it.
Eventually I'd ideally like to unconditionally require this attribute to be
placed on all `extern { ... }` blocks. For now though it seemed prudent to add
it as an unstable attribute, so for now it's not required (as that'd force usage
of a feature gate). Hopefully it doesn't take too long to "stabilize" this!
cc rust-lang-nursery/rust-wasm#29
This commit is an implementation of adding custom sections to wasm artifacts in
rustc. The intention here is to expose the ability of the wasm binary format to
contain custom sections with arbitrary user-defined data. Currently neither our
version of LLVM nor LLD supports this so the implementation is currently custom
to rustc itself.
The implementation here is to attach a `#[wasm_custom_section = "foo"]`
attribute to any `const` which has a type like `[u8; N]`. Other types of
constants aren't supported yet but may be added one day! This should hopefully
be enough to get off the ground with *some* custom section support.
The current semantics are that any constant tagged with `#[wasm_custom_section]`
section will be *appended* to the corresponding section in the final output wasm
artifact (and this affects dependencies linked in as well, not just the final
crate). This means that whatever is interpreting the contents must be able to
interpret binary-concatenated sections (or each constant needs to be in its own
custom section).
To test this change the existing `run-make` test suite was moved to a
`run-make-fulldeps` folder and a new `run-make` test suite was added which
applies to all targets by default. This test suite currently only has one test
which only runs for the wasm target (using a node.js script to use `WebAssembly`
in JS to parse the wasm output).
Detect illegal hidden lifetimes in `impl Trait`
This branch fixes#46541 -- however, it presently doesn't build because it also *breaks* a number of existing usages of impl Trait. I'm opening it as a WIP for now, just because we want to move on impl Trait, but I'll try to fix the problem in a bit.
~~(The problem is due to the fact that we apparently infer stricter lifetimes in closures that we need to; for example, if you capture a variable of type `&'a &'b u32`, we will put *precisely* those lifetimes into the closure, even if the closure would be happy with `&'a &'a u32`. This causes the present chance to affect things that are not invariant.)~~ fixed
r? @cramertj
