1 files changed, 155 insertions, 0 deletions
diff --git a/src/librustc_interface/interface.rs b/src/librustc_interface/interface.rs
new file mode 100644
index 00000000000..ec6b26afb8c
--- /dev/null
+++ b/src/librustc_interface/interface.rs
@@ -0,0 +1,155 @@
+use queries::Queries;
+use rustc::lint;
+use rustc::session::config::{self, Input};
+use rustc::session::{DiagnosticOutput, Session};
+use rustc::util::common::ErrorReported;
+use rustc_codegen_utils::codegen_backend::CodegenBackend;
+use rustc_data_structures::OnDrop;
+use rustc_data_structures::sync::Lrc;
+use rustc_data_structures::fx::{FxHashSet, FxHashMap};
+use rustc_metadata::cstore::CStore;
+use std::collections::HashSet;
+use std::io::Write;
+use std::path::PathBuf;
+use std::result;
+use std::sync::{Arc, Mutex};
+use syntax;
+use syntax::source_map::{FileLoader, SourceMap};
+use util;
+use profile;
+
+pub use passes::BoxedResolver;
+
+pub type Result<T> = result::Result<T, ErrorReported>;
+
+/// Represents a compiler session.
+/// Can be used run `rustc_interface` queries.
+/// Created by passing `Config` to `run_compiler`.
+pub struct Compiler {
+    pub(crate) sess: Lrc<Session>,
+    codegen_backend: Lrc<Box<dyn CodegenBackend>>,
+    source_map: Lrc<SourceMap>,
+    pub(crate) input: Input,
+    pub(crate) input_path: Option<PathBuf>,
+    pub(crate) output_dir: Option<PathBuf>,
+    pub(crate) output_file: Option<PathBuf>,
+    pub(crate) queries: Queries,
+    pub(crate) cstore: Lrc<CStore>,
+    pub(crate) crate_name: Option<String>,
+}
+
+impl Compiler {
+    pub fn session(&self) -> &Lrc<Session> {
+        &self.sess
+    }
+    pub fn codegen_backend(&self) -> &Lrc<Box<dyn CodegenBackend>> {
+        &self.codegen_backend
+    }
+    pub fn cstore(&self) -> &Lrc<CStore> {
+        &self.cstore
+    }
+    pub fn source_map(&self) -> &Lrc<SourceMap> {
+        &self.source_map
+    }
+    pub fn input(&self) -> &Input {
+        &self.input
+    }
+    pub fn output_dir(&self) -> &Option<PathBuf> {
+        &self.output_dir
+    }
+    pub fn output_file(&self) -> &Option<PathBuf> {
+        &self.output_file
+    }
+}
+
+/// The compiler configuration
+pub struct Config {
+    /// Command line options
+    pub opts: config::Options,
+
+    /// cfg! configuration in addition to the default ones
+    pub crate_cfg: FxHashSet<(String, Option<String>)>,
+
+    pub input: Input,
+    pub input_path: Option<PathBuf>,
+    pub output_dir: Option<PathBuf>,
+    pub output_file: Option<PathBuf>,
+    pub file_loader: Option<Box<dyn FileLoader + Send + Sync>>,
+    pub diagnostic_output: DiagnosticOutput,
+
+    /// Set to capture stderr output during compiler execution
+    pub stderr: Option<Arc<Mutex<Vec<u8>>>>,
+
+    pub crate_name: Option<String>,
+    pub lint_caps: FxHashMap<lint::LintId, lint::Level>,
+}
+
+pub fn run_compiler_in_existing_thread_pool<F, R>(config: Config, f: F) -> R
+where
+    F: FnOnce(&Compiler) -> R,
+{
+    let (sess, codegen_backend, source_map) = util::create_session(
+        config.opts,
+        config.crate_cfg,
+        config.diagnostic_output,
+        config.file_loader,
+        config.input_path.clone(),
+        config.lint_caps,
+    );
+
+    let cstore = Lrc::new(CStore::new(codegen_backend.metadata_loader()));
+
+    let compiler = Compiler {
+        sess,
+        codegen_backend,
+        source_map,
+        cstore,
+        input: config.input,
+        input_path: config.input_path,
+        output_dir: config.output_dir,
+        output_file: config.output_file,
+        queries: Default::default(),
+        crate_name: config.crate_name,
+    };
+
+    let _sess_abort_error = OnDrop(|| compiler.sess.diagnostic().print_error_count());
+
+    if compiler.sess.profile_queries() {
+        profile::begin(&compiler.sess);
+    }
+
+    let r = f(&compiler);
+
+    if compiler.sess.profile_queries() {
+        profile::dump(&compiler.sess, "profile_queries".to_string())
+    }
+
+    if compiler.sess.opts.debugging_opts.self_profile {
+        compiler.sess.profiler(|p| p.dump_raw_events(&compiler.sess.opts));
+    }
+
+    r
+}
+
+pub fn run_compiler<F, R>(mut config: Config, f: F) -> R
+where
+    F: FnOnce(&Compiler) -> R + Send,
+    R: Send,
+{
+    syntax::with_globals(move || {
+        let stderr = config.stderr.take();
+        util::spawn_thread_pool(
+            config.opts.debugging_opts.threads,
+            &stderr,
+            || run_compiler_in_existing_thread_pool(config, f),
+        )
+    })
+}
+
+pub fn default_thread_pool<F, R>(f: F) -> R
+where
+    F: FnOnce() -> R + Send,
+    R: Send,
+{
+    util::spawn_thread_pool(None, &None, f)
+}