Count all errors for `track_errors`

8 files changed, 77 insertions, 29 deletions

diff --git a/src/librustc/infer/mod.rs b/src/librustc/infer/mod.rs
index fc46fe383c9..eb007062e6d 100644
--- a/src/librustc/infer/mod.rs
+++ b/src/librustc/infer/mod.rs
@@ -171,6 +171,7 @@ pub struct InferCtxt<'a, 'tcx> {
     /// Track how many errors were reported when this infcx is created.
     /// If the number of errors increases, that's also a sign (line
     /// `tained_by_errors`) to avoid reporting certain kinds of errors.
+    // FIXME(matthewjasper) Merge into `tainted_by_errors_flag`
     err_count_on_creation: usize,
 
     /// This flag is true while there is an active snapshot.
diff --git a/src/librustc_errors/lib.rs b/src/librustc_errors/lib.rs
index 082f981338a..70bd25a9d57 100644
--- a/src/librustc_errors/lib.rs
+++ b/src/librustc_errors/lib.rs
@@ -307,7 +307,12 @@ pub use diagnostic_builder::DiagnosticBuilder;
 pub struct Handler {
     pub flags: HandlerFlags,
 
+    /// The number of errors that have been emitted, including duplicates.
+    ///
+    /// This is not necessarily the count that's reported to the user once
+    /// compilation ends.
     err_count: AtomicUsize,
+    deduplicated_err_count: AtomicUsize,
     emitter: Lock<Box<dyn Emitter + sync::Send>>,
     continue_after_error: AtomicBool,
     delayed_span_bugs: Lock<Vec<Diagnostic>>,
@@ -407,6 +412,7 @@ impl Handler {
         Handler {
             flags,
             err_count: AtomicUsize::new(0),
+            deduplicated_err_count: AtomicUsize::new(0),
             emitter: Lock::new(e),
             continue_after_error: AtomicBool::new(true),
             delayed_span_bugs: Lock::new(Vec::new()),
@@ -428,6 +434,7 @@ impl Handler {
     pub fn reset_err_count(&self) {
         // actually frees the underlying memory (which `clear` would not do)
         *self.emitted_diagnostics.borrow_mut() = Default::default();
+        self.deduplicated_err_count.store(0, SeqCst);
         self.err_count.store(0, SeqCst);
     }
 
@@ -660,10 +667,10 @@ impl Handler {
     }
 
     pub fn print_error_count(&self, registry: &Registry) {
-        let s = match self.err_count() {
+        let s = match self.deduplicated_err_count.load(SeqCst) {
             0 => return,
             1 => "aborting due to previous error".to_string(),
-            _ => format!("aborting due to {} previous errors", self.err_count())
+            count => format!("aborting due to {} previous errors", count)
         };
         if self.treat_err_as_bug() {
             return;
@@ -769,9 +776,12 @@ impl Handler {
         if self.emitted_diagnostics.borrow_mut().insert(diagnostic_hash) {
             self.emitter.borrow_mut().emit_diagnostic(db);
             if db.is_error() {
-                self.bump_err_count();
+                self.deduplicated_err_count.fetch_add(1, SeqCst);
             }
         }
+        if db.is_error() {
+            self.bump_err_count();
+        }
     }
 
     pub fn emit_artifact_notification(&self, path: &Path, artifact_type: &str) {
diff --git a/src/librustc_mir/const_eval.rs b/src/librustc_mir/const_eval.rs
index 284a8f40e1f..8c2bfc42b02 100644
--- a/src/librustc_mir/const_eval.rs
+++ b/src/librustc_mir/const_eval.rs
@@ -15,7 +15,6 @@ use rustc::ty::{self, TyCtxt, query::TyCtxtAt};
 use rustc::ty::layout::{self, LayoutOf, VariantIdx};
 use rustc::ty::subst::Subst;
 use rustc::traits::Reveal;
-use rustc::util::common::ErrorReported;
 use rustc_data_structures::fx::FxHashMap;
 
 use syntax::source_map::{Span, DUMMY_SP};
@@ -655,19 +654,12 @@ pub fn const_eval_raw_provider<'tcx>(
         if tcx.is_static(def_id) {
             // Ensure that if the above error was either `TooGeneric` or `Reported`
             // an error must be reported.
-            let reported_err = tcx.sess.track_errors(|| {
-                err.report_as_error(ecx.tcx,
-                                    "could not evaluate static initializer")
-            });
-            match reported_err {
-                Ok(v) => {
-                    tcx.sess.delay_span_bug(err.span,
-                                        &format!("static eval failure did not emit an error: {:#?}",
-                                        v));
-                    v
-                },
-                Err(ErrorReported) => ErrorHandled::Reported,
-            }
+            let v = err.report_as_error(ecx.tcx, "could not evaluate static initializer");
+            tcx.sess.delay_span_bug(
+                err.span,
+                &format!("static eval failure did not emit an error: {:#?}", v)
+            );
+            v
         } else if def_id.is_local() {
             // constant defined in this crate, we can figure out a lint level!
             match tcx.def_kind(def_id) {
diff --git a/src/librustc_save_analysis/span_utils.rs b/src/librustc_save_analysis/span_utils.rs
index 5831b0bcd8f..8905f475647 100644
--- a/src/librustc_save_analysis/span_utils.rs
+++ b/src/librustc_save_analysis/span_utils.rs
@@ -2,8 +2,6 @@ use rustc::session::Session;
 
 use crate::generated_code;
 
-use std::cell::Cell;
-
 use syntax::parse::lexer::{self, StringReader};
 use syntax::parse::token::{self, TokenKind};
 use syntax_pos::*;
@@ -11,16 +9,12 @@ use syntax_pos::*;
 #[derive(Clone)]
 pub struct SpanUtils<'a> {
     pub sess: &'a Session,
-    // FIXME given that we clone SpanUtils all over the place, this err_count is
-    // probably useless and any logic relying on it is bogus.
-    pub err_count: Cell<isize>,
 }
 
 impl<'a> SpanUtils<'a> {
     pub fn new(sess: &'a Session) -> SpanUtils<'a> {
         SpanUtils {
             sess,
-            err_count: Cell::new(0),
         }
     }
 
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index 40812b6a952..6d092011f7c 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -527,6 +527,8 @@ pub struct FnCtxt<'a, 'tcx> {
     /// checking this function. On exit, if we find that *more* errors
     /// have been reported, we will skip regionck and other work that
     /// expects the types within the function to be consistent.
+    // FIXME(matthewjasper) This should not exist, and it's not correct
+    // if type checking is run in parallel.
     err_count_on_creation: usize,
 
     ret_coercion: Option<RefCell<DynamicCoerceMany<'tcx>>>,
@@ -696,11 +698,9 @@ impl ItemLikeVisitor<'tcx> for CheckItemTypesVisitor<'tcx> {
     fn visit_impl_item(&mut self, _: &'tcx hir::ImplItem) { }
 }
 
-pub fn check_wf_new<'tcx>(tcx: TyCtxt<'tcx>) -> Result<(), ErrorReported> {
-    tcx.sess.track_errors(|| {
-        let mut visit = wfcheck::CheckTypeWellFormedVisitor::new(tcx);
-        tcx.hir().krate().par_visit_all_item_likes(&mut visit);
-    })
+pub fn check_wf_new<'tcx>(tcx: TyCtxt<'tcx>) {
+    let mut visit = wfcheck::CheckTypeWellFormedVisitor::new(tcx);
+    tcx.hir().krate().par_visit_all_item_likes(&mut visit);
 }
 
 fn check_mod_item_types<'tcx>(tcx: TyCtxt<'tcx>, module_def_id: DefId) {
diff --git a/src/librustc_typeck/lib.rs b/src/librustc_typeck/lib.rs
index cc6f7a07d96..8728f80bd98 100644
--- a/src/librustc_typeck/lib.rs
+++ b/src/librustc_typeck/lib.rs
@@ -321,6 +321,7 @@ pub fn check_crate<'tcx>(tcx: TyCtxt<'tcx>) -> Result<(), ErrorReported> {
 
     // this ensures that later parts of type checking can assume that items
     // have valid types and not error
+    // FIXME(matthewjasper) We shouldn't need to do this.
     tcx.sess.track_errors(|| {
         time(tcx.sess, "type collecting", || {
             for &module in tcx.hir().krate().modules.keys() {
@@ -353,7 +354,9 @@ pub fn check_crate<'tcx>(tcx: TyCtxt<'tcx>) -> Result<(), ErrorReported> {
         })?;
     }
 
-    time(tcx.sess, "wf checking", || check::check_wf_new(tcx))?;
+    tcx.sess.track_errors(|| {
+        time(tcx.sess, "wf checking", || check::check_wf_new(tcx));
+    })?;
 
     time(tcx.sess, "item-types checking", || {
         for &module in tcx.hir().krate().modules.keys() {
diff --git a/src/test/ui/consts/enum-discr-type-err.rs b/src/test/ui/consts/enum-discr-type-err.rs
new file mode 100644
index 00000000000..d66c4f47d03
--- /dev/null
+++ b/src/test/ui/consts/enum-discr-type-err.rs
@@ -0,0 +1,29 @@
+// Test that we mark enum discriminant values as having errors, even when the
+// diagnostic is deduplicated.
+
+struct F;
+struct T;
+
+impl F {
+    const V: i32 = 0;
+}
+
+impl T {
+    const V: i32 = 0;
+}
+
+macro_rules! mac {
+    ($( $v: ident = $s: ident,)*) => {
+        enum E {
+            $( $v = $s::V, )*
+            //~^ ERROR mismatched types
+        }
+    }
+}
+
+mac! {
+    A = F,
+    B = T,
+}
+
+fn main() {}
diff --git a/src/test/ui/consts/enum-discr-type-err.stderr b/src/test/ui/consts/enum-discr-type-err.stderr
new file mode 100644
index 00000000000..3c4fac7327d
--- /dev/null
+++ b/src/test/ui/consts/enum-discr-type-err.stderr
@@ -0,0 +1,19 @@
+error[E0308]: mismatched types
+  --> $DIR/enum-discr-type-err.rs:18:21
+   |
+LL |               $( $v = $s::V, )*
+   |                       ^^^^^ expected isize, found i32
+...
+LL | / mac! {
+LL | |     A = F,
+LL | |     B = T,
+LL | | }
+   | |_- in this macro invocation
+help: you can convert an `i32` to `isize` and panic if the converted value wouldn't fit
+   |
+LL |             $( $v = $s::V.try_into().unwrap(), )*
+   |                     ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.