rust/tests/ui-fulldeps/codegen-backend/auxiliary/the_backend.rs

//@ edition: 2021

#![feature(rustc_private)]
#![deny(warnings)]

extern crate rustc_codegen_ssa;
extern crate rustc_data_structures;
extern crate rustc_driver;
extern crate rustc_errors;
extern crate rustc_hir;
extern crate rustc_metadata;
extern crate rustc_middle;
extern crate rustc_session;
extern crate rustc_span;
extern crate rustc_symbol_mangling;
extern crate rustc_target;

use std::any::Any;

use rustc_codegen_ssa::traits::CodegenBackend;
use rustc_codegen_ssa::{CodegenResults, CrateInfo};
use rustc_data_structures::fx::FxIndexMap;
use rustc_metadata::EncodedMetadata;
use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
use rustc_middle::ty::TyCtxt;
use rustc_session::Session;
use rustc_session::config::OutputFilenames;

struct TheBackend;

impl CodegenBackend for TheBackend {
    fn locale_resource(&self) -> &'static str {
        ""
    }

    fn codegen_crate(&self, tcx: TyCtxt<'_>) -> Box<dyn Any> {
        Box::new(CodegenResults {
            modules: vec![],
            allocator_module: None,
            crate_info: CrateInfo::new(tcx, "fake_target_cpu".to_string()),
        })
    }

    fn join_codegen(
        &self,
        ongoing_codegen: Box<dyn Any>,
        _sess: &Session,
        _outputs: &OutputFilenames,
    ) -> (CodegenResults, FxIndexMap<WorkProductId, WorkProduct>) {
        let codegen_results = ongoing_codegen
            .downcast::<CodegenResults>()
            .expect("in join_codegen: ongoing_codegen is not a CodegenResults");
        (*codegen_results, FxIndexMap::default())
    }

    fn link(
        &self,
        sess: &Session,
        codegen_results: CodegenResults,
        _metadata: EncodedMetadata,
        outputs: &OutputFilenames,
    ) {
        use std::io::Write;

        use rustc_session::config::{CrateType, OutFileName};
        use rustc_session::output::out_filename;

        let crate_name = codegen_results.crate_info.local_crate_name;
        for &crate_type in sess.opts.crate_types.iter() {
            if crate_type != CrateType::Rlib {
                sess.dcx().fatal(format!("Crate type is {:?}", crate_type));
            }
            let output_name = out_filename(sess, crate_type, &outputs, crate_name);
            match output_name {
                OutFileName::Real(ref path) => {
                    let mut out_file = ::std::fs::File::create(path).unwrap();
                    writeln!(out_file, "This has been 'compiled' successfully.").unwrap();
                }
                OutFileName::Stdout => {
                    let mut stdout = std::io::stdout();
                    writeln!(stdout, "This has been 'compiled' successfully.").unwrap();
                }
            }
        }
    }
}

/// This is the entrypoint for a hot plugged rustc_codegen_llvm
#[no_mangle]
pub fn __rustc_codegen_backend() -> Box<dyn CodegenBackend> {
    Box::new(TheBackend)
}