Auto merge of #43730 - nrc:driver-shim, r=eddyb

Make the driver API a little more useful for a tools shim

Example use case: https://github.com/nrc/rls-rustc

src/librustc_driver/driver.rs

@@ -89,7 +89,7 @@ pub fn compile_input(sess: &Session,
     // large chunks of memory alive and we want to free them as soon as
     // possible to keep the peak memory usage low
     let (outputs, trans) = {
-        let krate = match phase_1_parse_input(sess, input) {
+        let krate = match phase_1_parse_input(control, sess, input) {
             Ok(krate) => krate,
             Err(mut parse_error) => {
                 parse_error.emit();
@@ -296,9 +296,13 @@ pub struct CompileController<'a> {
     pub after_llvm: PhaseController<'a>,
     pub compilation_done: PhaseController<'a>,
 
+    // FIXME we probably want to group the below options together and offer a
+    // better API, rather than this ad-hoc approach.
     pub make_glob_map: MakeGlobMap,
     // Whether the compiler should keep the ast beyond parsing.
     pub keep_ast: bool,
+    // -Zcontinue-parse-after-error
+    pub continue_parse_after_error: bool,
 }
 
 impl<'a> CompileController<'a> {
@@ -312,6 +316,7 @@ pub fn basic() -> CompileController<'a> {
             compilation_done: PhaseController::basic(),
             make_glob_map: MakeGlobMap::No,
             keep_ast: false,
+            continue_parse_after_error: false,
         }
     }
 }
@@ -484,10 +489,10 @@ fn state_after_llvm(input: &'a Input,
     }
 
     fn state_when_compilation_done(input: &'a Input,
-                                    session: &'tcx Session,
-                                    out_dir: &'a Option<PathBuf>,
-                                    out_file: &'a Option<PathBuf>)
-                                    -> Self {
+                                   session: &'tcx Session,
+                                   out_dir: &'a Option<PathBuf>,
+                                   out_file: &'a Option<PathBuf>)
+                                   -> Self {
         CompileState {
             out_file: out_file.as_ref().map(|s| &**s),
             ..CompileState::empty(input, session, out_dir)
@@ -495,9 +500,11 @@ fn state_when_compilation_done(input: &'a Input,
     }
 }
 
-pub fn phase_1_parse_input<'a>(sess: &'a Session, input: &Input) -> PResult<'a, ast::Crate> {
-    let continue_after_error = sess.opts.debugging_opts.continue_parse_after_error;
-    sess.diagnostic().set_continue_after_error(continue_after_error);
+pub fn phase_1_parse_input<'a>(control: &CompileController,
+                               sess: &'a Session,
+                               input: &Input)
+                               -> PResult<'a, ast::Crate> {
+    sess.diagnostic().set_continue_after_error(control.continue_parse_after_error);
 
     let krate = time(sess.time_passes(), "parsing", || {
         match *input {

src/librustc_driver/lib.rs

@@ -518,7 +518,8 @@ fn build_controller(&mut self,
                         -> CompileController<'a> {
         let mut control = CompileController::basic();
 
-        control.keep_ast = sess.opts.debugging_opts.keep_ast || save_analysis(sess);
+        control.keep_ast = sess.opts.debugging_opts.keep_ast;
+        control.continue_parse_after_error = sess.opts.debugging_opts.continue_parse_after_error;
 
         if let Some((ppm, opt_uii)) = parse_pretty(sess, matches) {
             if ppm.needs_ast_map(&opt_uii) {
@@ -574,19 +575,7 @@ fn build_controller(&mut self,
         }
 
         if save_analysis(sess) {
-            control.after_analysis.callback = box |state| {
-                time(state.session.time_passes(), "save analysis", || {
-                    save::process_crate(state.tcx.unwrap(),
-                                        state.expanded_crate.unwrap(),
-                                        state.analysis.unwrap(),
-                                        state.crate_name.unwrap(),
-                                        None,
-                                        DumpHandler::new(state.out_dir,
-                                                         state.crate_name.unwrap()))
-                });
-            };
-            control.after_analysis.run_callback_on_error = true;
-            control.make_glob_map = resolve::MakeGlobMap::Yes;
+            enable_save_analysis(&mut control);
         }
 
         if sess.print_fuel_crate.is_some() {
@@ -603,6 +592,23 @@ fn build_controller(&mut self,
     }
 }
 
+pub fn enable_save_analysis(control: &mut CompileController) {
+    control.keep_ast = true;
+    control.after_analysis.callback = box |state| {
+        time(state.session.time_passes(), "save analysis", || {
+            save::process_crate(state.tcx.unwrap(),
+                                state.expanded_crate.unwrap(),
+                                state.analysis.unwrap(),
+                                state.crate_name.unwrap(),
+                                None,
+                                DumpHandler::new(state.out_dir,
+                                                 state.crate_name.unwrap()))
+        });
+    };
+    control.after_analysis.run_callback_on_error = true;
+    control.make_glob_map = resolve::MakeGlobMap::Yes;
+}
+
 fn save_analysis(sess: &Session) -> bool {
     sess.opts.debugging_opts.save_analysis
 }
@@ -1215,7 +1221,7 @@ pub fn diagnostics_registry() -> errors::registry::Registry {
     Registry::new(&all_errors)
 }
 
-fn get_args() -> Vec<String> {
+pub fn get_args() -> Vec<String> {
     env::args_os().enumerate()
         .map(|(i, arg)| arg.into_string().unwrap_or_else(|arg| {
              early_error(ErrorOutputType::default(),

src/librustc_driver/test.rs

@@ -119,7 +119,9 @@ fn test_env<F>(source_string: &str,
         name: driver::anon_src(),
         input: source_string.to_string(),
     };
-    let krate = driver::phase_1_parse_input(&sess, &input).unwrap();
+    let krate = driver::phase_1_parse_input(&driver::CompileController::basic(),
+                                            &sess,
+                                            &input).unwrap();
     let driver::ExpansionResult { defs, resolutions, mut hir_forest, .. } = {
         driver::phase_2_configure_and_expand(&sess,
                                              &cstore,

src/librustdoc/core.rs

@@ -155,7 +155,9 @@ pub fn run_core(search_paths: SearchPaths,
     target_features::add_configuration(&mut cfg, &sess);
     sess.parse_sess.config = cfg;
 
-    let krate = panictry!(driver::phase_1_parse_input(&sess, &input));
+    let krate = panictry!(driver::phase_1_parse_input(&driver::CompileController::basic(),
+                                                      &sess,
+                                                      &input));
 
     let name = link::find_crate_name(Some(&sess), &krate.attrs, &input);
 

src/librustdoc/test.rs

@@ -91,7 +91,9 @@ pub fn run(input: &str,
     sess.parse_sess.config =
         config::build_configuration(&sess, config::parse_cfgspecs(cfgs.clone()));
 
-    let krate = panictry!(driver::phase_1_parse_input(&sess, &input));
+    let krate = panictry!(driver::phase_1_parse_input(&driver::CompileController::basic(),
+                                                      &sess,
+                                                      &input));
     let driver::ExpansionResult { defs, mut hir_forest, .. } = {
         phase_2_configure_and_expand(
             &sess, &cstore, krate, None, "rustdoc-test", None, MakeGlobMap::No, |_| Ok(())