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Boshen
777f02ae10
## Summary Introduces `oxc_diagnostics::Diagnostics` — a `Vec<OxcDiagnostic>` newtype that knows the difference between errors and warnings — and makes it the standard diagnostics return value across oxc. - **New type**: `Diagnostics` with `has_errors()`, `has_warnings()`, `errors()`, `warnings()`, plus `Vec`-like ergonomics (Deref, `IntoIterator`, `Extend`, `From`/`Into<Vec>`) so most call sites are unchanged. - **Return types**: `ParserReturn`, `SemanticBuilderReturn`, `IsolatedDeclarationsReturn`, the React Compiler `TransformResult`/`LintResult`, and `TransformerReturn` now expose `diagnostics: Diagnostics` instead of `errors: Vec<OxcDiagnostic>` (the React Compiler's separate `errors`/`warnings` are merged into one severity-tagged list). - **Behaviour**: a React Compiler **error** now stops the transform (no output), while **warnings** flow through and the transform continues. `compile()` aborts codegen only when `diagnostics.has_errors()` — warnings alone no longer abort (previously any diagnostic did). ## Breaking change Consumers reading `*.errors` on these return values must read `*.diagnostics`. React Compiler consumers that read `.errors`/`.warnings` separately should use `diagnostics.has_errors()` / `diagnostics.errors()` / `diagnostics.warnings()`. Parser/semantic/isolated-declarations fatality is otherwise unchanged. Builds on the React Compiler transform feature (#23201). 🤖 Generated with [Claude Code](https://claude.com/claude-code)
80 lines
2.3 KiB
Rust
80 lines
2.3 KiB
Rust
#![expect(clippy::print_stdout)]
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//! # Dead Code Elimination Example
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//!
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//! This example demonstrates dead code elimination (DCE) using the Oxc compressor.
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//! It removes unreachable code and unused variables.
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//!
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//! ## Usage
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//!
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//! Create a `test.js` file and run:
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//! ```bash
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//! cargo run -p oxc_minifier --example dce [filename] [--nospace] [--twice]
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//! ```
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//!
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//! ## Options
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//!
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//! - `--nospace`: Remove extra whitespace
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//! - `--twice`: Test idempotency by running twice
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//! - `--max-iterations <u8>`: Set the maximum number of compress pass iterations
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use std::path::Path;
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use oxc_allocator::Allocator;
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use oxc_codegen::{Codegen, CodegenOptions};
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use oxc_minifier::{CompressOptions, Compressor};
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use oxc_parser::Parser;
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use oxc_span::SourceType;
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use pico_args::Arguments;
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// Instruction:
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// create a `test.js`,
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// run `cargo run -p oxc_minifier --example dce`
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fn main() -> std::io::Result<()> {
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let mut args = Arguments::from_env();
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let nospace = args.contains("--nospace");
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let twice = args.contains("--twice");
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let max_iterations = args
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.opt_value_from_str::<&str, u8>("--max-iterations")
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.expect("Invalid number for --max-iterations");
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let name = args.free_from_str().unwrap_or_else(|_| "test.js".to_string());
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let path = Path::new(&name);
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let source_text = std::fs::read_to_string(path)?;
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let source_type = SourceType::from_path(path).unwrap();
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let mut allocator = Allocator::default();
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let printed = dce(&allocator, &source_text, source_type, nospace, max_iterations);
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println!("{printed}");
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if twice {
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allocator.reset();
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let printed2 = dce(&allocator, &printed, source_type, nospace, None);
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println!("{printed2}");
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println!("same = {}", printed == printed2);
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}
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Ok(())
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}
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fn dce(
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allocator: &Allocator,
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source_text: &str,
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source_type: SourceType,
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nospace: bool,
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max_iterations: Option<u8>,
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) -> String {
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let ret = Parser::new(allocator, source_text, source_type).parse();
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assert!(ret.diagnostics.is_empty());
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let mut program = ret.program;
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Compressor::new(allocator).dead_code_elimination(
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&mut program,
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CompressOptions { max_iterations, ..CompressOptions::dce() },
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);
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Codegen::new()
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.with_options(CodegenOptions { minify: nospace, ..CodegenOptions::default() })
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.build(&program)
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.code
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}
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