Example: Getting diagnostic through rustc_interface
rustc_interface
allows you to intercept diagnostics that would otherwise be printed to stderr.
Getting diagnostics
To get diagnostics from the compiler,
configure rustc_interface::Config
to output diagnostic to a buffer,
and run TyCtxt.analysis
:
#![allow(unused)] fn main() { // See https://github.com/rust-lang/rustc-dev-guide/blob/master/examples/rustc-driver-getting-diagnostics.rs for complete program. let buffer = sync::Arc::new(sync::Mutex::new(Vec::new())); let config = rustc_interface::Config { opts: config::Options { // Configure the compiler to emit diagnostics in compact JSON format. error_format: config::ErrorOutputType::Json { pretty: false, json_rendered: rustc_errors::emitter::HumanReadableErrorType::Default( rustc_errors::emitter::ColorConfig::Never, ), }, /* other config */ }, // Redirect the diagnostic output of the compiler to a buffer. diagnostic_output: rustc_session::DiagnosticOutput::Raw(Box::from(DiagnosticSink( buffer.clone(), ))), /* other config */ }; rustc_interface::run_compiler(config, |compiler| { compiler.enter(|queries| { queries.global_ctxt().unwrap().take().enter(|tcx| { // Run the analysis phase on the local crate to trigger the type error. tcx.analysis(rustc_hir::def_id::LOCAL_CRATE); }); }); }); // Read buffered diagnostics. let diagnostics = String::from_utf8(buffer.lock().unwrap().clone()).unwrap(); }