mirror of https://github.com/bazelbuild/rules_rust
828c8071f3
Proposal for https://github.com/bazelbuild/rules_rust/issues/1642 Duplicates https://github.com/bazelbuild/rules_rust/pull/1643 (special thanks to @freeformstu) ### Summary Rustc can be used to expand all macros so that you can inspect the generated source files easier. This feature is enabled via `-Zunpretty={mode}`. The `-Z` flag is only available in the nightly version of `rustc` (https://github.com/rust-lang/rust/issues/43364). ### Unprettying Build and test your targets normally. ``` bazel build //:ok_binary INFO: Analyzed target //:ok_binary (0 packages loaded, 0 targets configured). INFO: Found 1 target... Target //:ok_binary up-to-date: bazel-bin/ok_binary INFO: Elapsed time: 0.081s, Critical Path: 0.00s INFO: 1 process: 1 internal. INFO: Build completed successfully, 1 total action ``` Use the aspect to generate the expanded files in as a one-off build. (`.bazelrc`) ``` # Enable unpretty for all targets in the workspace build:unpretty --aspects=@rules_rust//rust:defs.bzl%rust_unpretty_aspect build:unpretty --output_groups=+rust_unpretty # `unpretty` requires the nightly toolchain. See tracking issue: # https://github.com/rust-lang/rust/issues/43364 build:unpretty --@rules_rust//rust/toolchain/channel=nightly ``` ``` bazel build --config=unpretty //:ok_binary INFO: Analyzed target //:ok_binary (1 packages loaded, 2 targets configured). INFO: Found 1 target... Aspect @rules_rust//rust/private:unpretty.bzl%rust_unpretty_aspect of //:ok_binary up-to-date: bazel-bin/ok_binary.expand.rs INFO: Elapsed time: 0.149s, Critical Path: 0.00s INFO: 1 process: 1 internal. INFO: Build completed successfully, 1 total action ``` Targeting tests is valid as well. ``` bazel build --config=unpretty //:ok_test INFO: Analyzed target //:ok_test (0 packages loaded, 2 targets configured). INFO: Found 1 target... Aspect @rules_rust//rust/private:unpretty.bzl%rust_expand_aspect of //:ok_test up-to-date: bazel-bin/test-397521499/ok_test.expand.rs INFO: Elapsed time: 0.113s, Critical Path: 0.00s INFO: 1 process: 1 internal. INFO: Build completed successfully, 1 total action ``` Finally, manually wire up a `rust_unpretty` target explicitly if you want a target to build. This rule is unique compared to the aspect in that it forces a transition to a nightly toolchain so that `-Zunpretty` can be used. ```starlark load("@rules_rust//rust:defs.bzl", "rust_binary", "rust_unpretty") rust_binary( name = "ok_binary", srcs = ["src/main.rs"], edition = "2021", ) rust_unpretty( name = "ok_binary_expand", deps = [":ok_binary"], ) ``` ``` bazel build //:ok_binary_expand INFO: Analyzed target //:ok_binary_expand (0 packages loaded, 1 target configured). INFO: Found 1 target... Target //:ok_binary_expand up-to-date: bazel-bin/ok_binary.expand.rs INFO: Elapsed time: 0.090s, Critical Path: 0.00s INFO: 1 process: 1 internal. INFO: Build completed successfully, 1 total action ``` |
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| .. | ||
| BUILD.bazel | ||
| proc_macro.rs | ||
| proc_macro.unpretty.expanded.rs | ||
| proc_macro_test.rs | ||
| proc_macro_test.unpretty.expanded.rs | ||