System Initiative

# Copyright (c) Meta Platforms, Inc. and affiliates. # # This source code is licensed under both the MIT license found in the # LICENSE-MIT file in the root directory of this source tree and the Apache # License, Version 2.0 found in the LICENSE-APACHE file in the root directory # of this source tree. # Typically, rustc has access to a "sysroot," which is a directory tree with a known layout that # contains a number of pre-compiled rlibs that are available by default. This includes, for example, # the standard library. If explicit sysroot deps are passed on the toolchain, the sysroot is not # made available to rustc. Instead, all crates which would normally be members of the sysroot must # be passed explicitly here. # # Most sysroot deps typically behave as if they were transitive dependencies of the crate being # compiled. That means they are not guaranteed to be included in the link, and the user must write # `extern crate;` to access them. The crates singled out here behave differently in that regard, # which is why they are singled out. # # Toolchains are free to omit any crates they like from this list; those crates will simply not be # available in the compilation. RustExplicitSysrootDeps = record( core = Dependency | None, proc_macro = Dependency | None, std = Dependency | None, panic_unwind = Dependency | None, panic_abort = Dependency | None, others = list[Dependency], ) PanicRuntime = enum("unwind", "abort", "none") # FIXME(JakobDegen): These all have default values for historical reasons. Some of them certainly # should, but some of them probably shouldn't? # @unsorted-dict-items rust_toolchain_attrs = { # Report unused dependencies "report_unused_deps": provider_field(bool, default = False), # Rustc target triple to use # https://doc.rust-lang.org/rustc/platform-support.html "rustc_target_triple": provider_field(str | None, default = None), # Baseline compiler config "rustc_flags": provider_field(list[typing.Any], default = []), # Rustc flags, except that they are applied on the command line after the # target's rustc flags "extra_rustc_flags": provider_field(list[typing.Any], default = []), # Path to search for custom target .json files "rust_target_path": provider_field(Dependency | None, default = None), # Flags applied only on check builds "rustc_check_flags": provider_field(list[typing.Any], default = []), # Extra flags when building binaries "rustc_binary_flags": provider_field(list[typing.Any], default = []), # Extra flags for doing building tests "rustc_test_flags": provider_field(list[typing.Any], default = []), # Extra flags when coverage is enabled for a target # FIXME(JakobDegen): Can't use `list[str]` here, because then the default is wrong, but can't # use a non-empty list as the default because lists are mutable "rustc_coverage_flags": provider_field(typing.Any, default = ("-Cinstrument-coverage",)), # Extra env variables that should be made available to the rustdoc executable. "rustdoc_env": provider_field(dict[str, typing.Any], default = {}), # Extra flags for rustdoc invocations "rustdoc_flags": provider_field(list[typing.Any], default = []), # When you `buck test` a library, also compile and run example code in its # documentation comments. "doctests": provider_field(bool, default = False), # The Rust compiler (rustc) "compiler": provider_field(RunInfo | None, default = None), # Rust documentation extractor (rustdoc) "rustdoc": provider_field(RunInfo | None, default = None), # Clippy (linter) version of the compiler "clippy_driver": provider_field(RunInfo | None, default = None), # The default edition to use, if not specified. "default_edition": provider_field(str | None, default = None), # Lints "allow_lints": provider_field(list[typing.Any], default = []), "deny_lints": provider_field(list[typing.Any], default = []), "warn_lints": provider_field(list[typing.Any], default = []), # Deny-on-Check lints are handled differently depending on the build. # # For check builds, e.g. [check], [diag.json], [clippy.json] subtargets, or the default target # for `rust_library` rules, these lints will be applied as Deny Lints. Importantly, this means # that when you call `buck build :rust_lib` or use tools like arc rust-check or rustfix, these # lints will be surfaced as errors. # # However, for "regular" builds, e.g. when building tests or binaries, or building this target # as a dependency of another target, these flags will be surfaced only as warnings. The primary # benefit here is that you can develop + test your code as normal and will not be blocked by # these lints. However, once you run rust check, or submit your code to phabricator, these # lints will prevent you from landing your code. This way we can introduce lints that we'd like # to deny from our codebase without slowing down your inner dev loop, or encouraging you to # --cap-warns=lint for your projects. "deny_on_check_lints": provider_field(list[typing.Any], default = []), # Clippy configuration file clippy.toml "clippy_toml": provider_field(Artifact | None, default = None), # Setting this enables additional behaviors that improves linking at the # cost of using unstable implementation details of rustc. At the moment, # this is only used for linking rlibs into C++/C builds, instead of using # staticlibs, but that's expected to change. # # FIXME(JakobDegen): This should require `explicit_sysroot_deps` in the # future. "advanced_unstable_linking": provider_field(bool, default = False), # Override the implicit sysroot with the provided Artifact containing a directory to # a prebuilt sysroot. Will be forwarded to rustc as `--sysroot=<sysroot_path>`. Only # one of this and `explicit_sysroot_deps` may be set. "sysroot_path": provider_field(Artifact | None, default = None), # See the documentation on the type for details "explicit_sysroot_deps": provider_field(RustExplicitSysrootDeps | None, default = None), # The panic runtime to use. This is a part of the target definition and is # normally inferred by rustc. This field: # # - Should be set to `"none"` on nostd targets # - Must be set correctly if `explicit_sysroot_deps` and # `advanced_unstable_linking` are used. You can find the correct value # for a given target triple via `rustc --print target-spec-json` # - Otherwise can typically be safely defaulted to `"unwind"`. It is, # however, still the preferred way of configuring `-Cpanic=abort`, since # it makes sure that the flag is consistent across the crate graph. # # It's worth pointing out that the way that rustc handles this is a bit # weird. It requires the panic runtime to be a nostd crate, despite the fact # that it is only ever useful in combination with std. We don't impose such # a requirement. # # FIXME(JakobDegen): Fix `enum` so that we can set `unwind` as the default "panic_runtime": provider_field(PanicRuntime), # Setting this allows Rust rules to use features which are only available # on nightly release. "nightly_features": provider_field(bool, default = False), # The `cargo llvm-lines` binary - if present, Rust targets have a # `llvm-lines` subtarget "llvm_lines_tool": provider_field(RunInfo | None, default = None), # The `crox` binary from measure-me, if present, used to generate a # self-profile trace subtarget "measureme_crox": provider_field(RunInfo | None, default = None), # Constructs an upload command for the given chrome trace "make_trace_upload": provider_field(typing.Callable[[Artifact], RunInfo] | None, default = None), # Suffix to append onto all -Cmetadata arguments to differentiate the same # crate in different configurations "configuration_hash": provider_field(str | None, default = None), # Error handler used to categorize rust errors encountered by users "rust_error_handler": provider_field(typing.Any, default = None), } RustToolchainInfo = provider(fields = rust_toolchain_attrs)