Auto merge of #64272 - Mark-Simulacrum:parallel-handler, r=estebank

Refactor librustc_errors::Handler API

This should be reviewed by-commit.

The last commit moves all fields into an inner struct behind a single lock; this is done to prevent possible deadlocks in a multi-threaded compiler, as well as inconsistent state observation.

6 files changed, 22 insertions, 23 deletions

diff --git a/src/librustc/dep_graph/graph.rs b/src/librustc/dep_graph/graph.rs
index 7eea336cbbf..e76a70350b3 100644
--- a/src/librustc/dep_graph/graph.rs
+++ b/src/librustc/dep_graph/graph.rs
@@ -1,4 +1,4 @@
-use errors::{Diagnostic, DiagnosticBuilder};
+use errors::Diagnostic;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::indexed_vec::{Idx, IndexVec};
@@ -819,7 +819,7 @@ impl DepGraph {
             let handle = tcx.sess.diagnostic();
 
             for diagnostic in diagnostics {
-                DiagnosticBuilder::new_diagnostic(handle, diagnostic).emit();
+                handle.emit_diagnostic(&diagnostic);
             }
 
             // Mark the node as green now that diagnostics are emitted
diff --git a/src/librustc/infer/error_reporting/mod.rs b/src/librustc/infer/error_reporting/mod.rs
index ab24b3f2f05..0b6740d7bbb 100644
--- a/src/librustc/infer/error_reporting/mod.rs
+++ b/src/librustc/infer/error_reporting/mod.rs
@@ -1119,7 +1119,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                     Some((expected, found)) => Some((expected, found)),
                     None => {
                         // Derived error. Cancel the emitter.
-                        self.tcx.sess.diagnostic().cancel(diag);
+                        diag.cancel();
                         return;
                     }
                 };
diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs
index 723855c7c29..5eda3df3781 100644
--- a/src/librustc/session/config.rs
+++ b/src/librustc/session/config.rs
@@ -1855,7 +1855,7 @@ pub fn rustc_optgroups() -> Vec<RustcOptGroup> {
 struct NullEmitter;
 
 impl errors::emitter::Emitter for NullEmitter {
-    fn emit_diagnostic(&mut self, _: &errors::DiagnosticBuilder<'_>) {}
+    fn emit_diagnostic(&mut self, _: &errors::Diagnostic) {}
 }
 
 // Converts strings provided as `--cfg [cfgspec]` into a `crate_cfg`.
diff --git a/src/librustc/session/config/tests.rs b/src/librustc/session/config/tests.rs
index 3d6312548a4..9eb68056bfd 100644
--- a/src/librustc/session/config/tests.rs
+++ b/src/librustc/session/config/tests.rs
@@ -87,7 +87,7 @@ fn test_can_print_warnings() {
         let registry = errors::registry::Registry::new(&[]);
         let (sessopts, _) = build_session_options_and_crate_config(&matches);
         let sess = build_session(sessopts, None, registry);
-        assert!(!sess.diagnostic().flags.can_emit_warnings);
+        assert!(!sess.diagnostic().can_emit_warnings());
     });
 
     syntax::with_default_globals(|| {
@@ -97,7 +97,7 @@ fn test_can_print_warnings() {
         let registry = errors::registry::Registry::new(&[]);
         let (sessopts, _) = build_session_options_and_crate_config(&matches);
         let sess = build_session(sessopts, None, registry);
-        assert!(sess.diagnostic().flags.can_emit_warnings);
+        assert!(sess.diagnostic().can_emit_warnings());
     });
 
     syntax::with_default_globals(|| {
@@ -105,7 +105,7 @@ fn test_can_print_warnings() {
         let registry = errors::registry::Registry::new(&[]);
         let (sessopts, _) = build_session_options_and_crate_config(&matches);
         let sess = build_session(sessopts, None, registry);
-        assert!(sess.diagnostic().flags.can_emit_warnings);
+        assert!(sess.diagnostic().can_emit_warnings());
     });
 }
 
diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs
index 8656ebb2e6d..a24fed8f21c 100644
--- a/src/librustc/session/mod.rs
+++ b/src/librustc/session/mod.rs
@@ -365,12 +365,6 @@ impl Session {
     pub fn span_note_without_error<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
         self.diagnostic().span_note_without_error(sp, msg)
     }
-    pub fn span_unimpl<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
-        self.diagnostic().span_unimpl(sp, msg)
-    }
-    pub fn unimpl(&self, msg: &str) -> ! {
-        self.diagnostic().unimpl(msg)
-    }
 
     pub fn buffer_lint<S: Into<MultiSpan>>(
         &self,
@@ -1040,6 +1034,7 @@ fn default_emitter(
     source_map: &Lrc<source_map::SourceMap>,
     emitter_dest: Option<Box<dyn Write + Send>>,
 ) -> Box<dyn Emitter + sync::Send> {
+    let external_macro_backtrace = sopts.debugging_opts.external_macro_backtrace;
     match (sopts.error_format, emitter_dest) {
         (config::ErrorOutputType::HumanReadable(kind), dst) => {
             let (short, color_config) = kind.unzip();
@@ -1048,6 +1043,7 @@ fn default_emitter(
                 let emitter = AnnotateSnippetEmitterWriter::new(
                     Some(source_map.clone()),
                     short,
+                    external_macro_backtrace,
                 );
                 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
             } else {
@@ -1058,6 +1054,7 @@ fn default_emitter(
                         short,
                         sopts.debugging_opts.teach,
                         sopts.debugging_opts.terminal_width,
+                        external_macro_backtrace,
                     ),
                     Some(dst) => EmitterWriter::new(
                         dst,
@@ -1066,6 +1063,7 @@ fn default_emitter(
                         false, // no teach messages when writing to a buffer
                         false, // no colors when writing to a buffer
                         None,  // no terminal width
+                        external_macro_backtrace,
                     ),
                 };
                 Box::new(emitter.ui_testing(sopts.debugging_opts.ui_testing))
@@ -1077,6 +1075,7 @@ fn default_emitter(
                 source_map.clone(),
                 pretty,
                 json_rendered,
+                external_macro_backtrace,
             ).ui_testing(sopts.debugging_opts.ui_testing),
         ),
         (config::ErrorOutputType::Json { pretty, json_rendered }, Some(dst)) => Box::new(
@@ -1086,6 +1085,7 @@ fn default_emitter(
                 source_map.clone(),
                 pretty,
                 json_rendered,
+                external_macro_backtrace,
             ).ui_testing(sopts.debugging_opts.ui_testing),
         ),
     }
@@ -1382,13 +1382,13 @@ pub fn early_error(output: config::ErrorOutputType, msg: &str) -> ! {
     let emitter: Box<dyn Emitter + sync::Send> = match output {
         config::ErrorOutputType::HumanReadable(kind) => {
             let (short, color_config) = kind.unzip();
-            Box::new(EmitterWriter::stderr(color_config, None, short, false, None))
+            Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
         }
         config::ErrorOutputType::Json { pretty, json_rendered } =>
-            Box::new(JsonEmitter::basic(pretty, json_rendered)),
+            Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
     };
     let handler = errors::Handler::with_emitter(true, None, emitter);
-    handler.emit(&MultiSpan::new(), msg, errors::Level::Fatal);
+    handler.struct_fatal(msg).emit();
     errors::FatalError.raise();
 }
 
@@ -1396,13 +1396,13 @@ pub fn early_warn(output: config::ErrorOutputType, msg: &str) {
     let emitter: Box<dyn Emitter + sync::Send> = match output {
         config::ErrorOutputType::HumanReadable(kind) => {
             let (short, color_config) = kind.unzip();
-            Box::new(EmitterWriter::stderr(color_config, None, short, false, None))
+            Box::new(EmitterWriter::stderr(color_config, None, short, false, None, false))
         }
         config::ErrorOutputType::Json { pretty, json_rendered } =>
-            Box::new(JsonEmitter::basic(pretty, json_rendered)),
+            Box::new(JsonEmitter::basic(pretty, json_rendered, false)),
     };
     let handler = errors::Handler::with_emitter(true, None, emitter);
-    handler.emit(&MultiSpan::new(), msg, errors::Level::Warning);
+    handler.struct_warn(msg).emit();
 }
 
 pub type CompileResult = Result<(), ErrorReported>;
diff --git a/src/librustc/ty/query/plumbing.rs b/src/librustc/ty/query/plumbing.rs
index d199a26475b..a1828bb5ab7 100644
--- a/src/librustc/ty/query/plumbing.rs
+++ b/src/librustc/ty/query/plumbing.rs
@@ -330,14 +330,13 @@ impl<'tcx> TyCtxt<'tcx> {
                 let mut i = 0;
 
                 while let Some(query) = current_query {
-                    let mut db = DiagnosticBuilder::new(icx.tcx.sess.diagnostic(),
-                        Level::FailureNote,
+                    let mut diag = Diagnostic::new(Level::FailureNote,
                         &format!("#{} [{}] {}",
                                  i,
                                  query.info.query.name(),
                                  query.info.query.describe(icx.tcx)));
-                    db.set_span(icx.tcx.sess.source_map().def_span(query.info.span));
-                    icx.tcx.sess.diagnostic().force_print_db(db);
+                    diag.span = icx.tcx.sess.source_map().def_span(query.info.span).into();
+                    icx.tcx.sess.diagnostic().force_print_diagnostic(diag);
 
                     current_query = query.parent.clone();
                     i += 1;