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
