Rollup merge of rust-lang#69926 - RoccoDev:master, r=estebank,varkor

rustc: Add a warning count upon completion

This adds a `build completed with one warning/x warnings` message, similar to the already present `aborted due to previous error` message.

However, tests fail because they aren't expecting this message to be printed to stderr (or stdout).
Do we edit the tests or do we try to work around it?

Author: Dylan-DPC

src/librustc_errors/lib.rs

@@ -312,6 +312,9 @@ struct HandlerInner {
     /// The stashed diagnostics count towards the total error count.
     /// When `.abort_if_errors()` is called, these are also emitted.
     stashed_diagnostics: FxIndexMap<(Span, StashKey), Diagnostic>,
+
+    /// The warning count, used for a recap upon finishing
+    deduplicated_warn_count: usize,
 }
 
 /// A key denoting where from a diagnostic was stashed.
@@ -414,6 +417,7 @@ impl Handler {
                 flags,
                 err_count: 0,
                 deduplicated_err_count: 0,
+                deduplicated_warn_count: 0,
                 emitter,
                 delayed_span_bugs: Vec::new(),
                 taught_diagnostics: Default::default(),
@@ -439,6 +443,7 @@ impl Handler {
         let mut inner = self.inner.borrow_mut();
         inner.err_count = 0;
         inner.deduplicated_err_count = 0;
+        inner.deduplicated_warn_count = 0;
 
         // actually free the underlying memory (which `clear` would not do)
         inner.delayed_span_bugs = Default::default();
@@ -745,6 +750,8 @@ impl HandlerInner {
             self.emitter.emit_diagnostic(diagnostic);
             if diagnostic.is_error() {
                 self.deduplicated_err_count += 1;
+            } else if diagnostic.level == Warning {
+                self.deduplicated_warn_count += 1;
             }
         }
         if diagnostic.is_error() {
@@ -763,16 +770,30 @@ impl HandlerInner {
     fn print_error_count(&mut self, registry: &Registry) {
         self.emit_stashed_diagnostics();
 
-        let s = match self.deduplicated_err_count {
-            0 => return,
+        let warnings = match self.deduplicated_warn_count {
+            0 => String::new(),
+            1 => "1 warning emitted".to_string(),
+            count => format!("{} warnings emitted", count),
+        };
+        let errors = match self.deduplicated_err_count {
+            0 => String::new(),
             1 => "aborting due to previous error".to_string(),
             count => format!("aborting due to {} previous errors", count),
         };
         if self.treat_err_as_bug() {
             return;
         }
 
-        let _ = self.fatal(&s);
+        match (errors.len(), warnings.len()) {
+            (0, 0) => return,
+            (0, _) => self.emit_diagnostic(&Diagnostic::new(Level::Warning, &warnings)),
+            (_, 0) => {
+                let _ = self.fatal(&errors);
+            }
+            (_, _) => {
+                let _ = self.fatal(&format!("{}; {}", &errors, &warnings));
+            }
+        }
 
         let can_show_explain = self.emitter.should_show_explain();
         let are_there_diagnostics = !self.emitted_diagnostic_codes.is_empty();

src/test/rustdoc-ui/deprecated-attrs.stderr

@@ -7,3 +7,5 @@ warning: the `#![doc(passes = "...")]` attribute is considered deprecated
    |
    = warning: see issue #44136 <https://github.com/rust-lang/rust/issues/44136> for more information
 
+warning: 2 warnings emitted
+

src/test/rustdoc-ui/intra-links-warning-crlf.stderr

@@ -31,3 +31,5 @@ LL |  * It also has an [error].
    |
    = help: to escape `[` and `]` characters, just add '\' before them like `\[` or `\]`
 
+warning: 4 warnings emitted
+

src/test/rustdoc-ui/intra-links-warning.stderr

@@ -177,3 +177,5 @@ LL | f!("Foo\nbar [BarF] bar\nbaz");
    = help: to escape `[` and `]` characters, just add '\' before them like `\[` or `\]`
    = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
+warning: 19 warnings emitted
+

src/test/rustdoc-ui/invalid-syntax.stderr

@@ -147,3 +147,5 @@ help: mark blocks that do not contain Rust code as text
 LL | /// ```text
    |     ^^^^^^^
 
+warning: 12 warnings emitted
+

src/test/ui-fulldeps/feature-gate-plugin.stderr

@@ -15,6 +15,6 @@ LL | #![plugin(empty_plugin)]
    |
    = note: `#[warn(deprecated)]` on by default
 
-error: aborting due to previous error
+error: aborting due to previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0658`.

src/test/ui-fulldeps/gated-plugin.stderr

@@ -15,6 +15,6 @@ LL | #![plugin(empty_plugin)]
    |
    = note: `#[warn(deprecated)]` on by default
 
-error: aborting due to previous error
+error: aborting due to previous error; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0658`.

src/test/ui-fulldeps/issue-15778-fail.stderr

@@ -18,5 +18,5 @@ LL | | pub fn main() { }
    |
    = note: requested on the command line with `-D crate-not-okay`
 
-error: aborting due to previous error
+error: aborting due to previous error; 1 warning emitted
 

src/test/ui-fulldeps/issue-15778-pass.stderr

@@ -6,3 +6,5 @@ LL | #![plugin(lint_for_crate_rpass)]
    |
    = note: `#[warn(deprecated)]` on by default
 
+warning: 1 warning emitted
+

src/test/ui-fulldeps/issue-40001.stderr

@@ -6,3 +6,5 @@ LL | #![plugin(issue_40001_plugin)]
    |
    = note: `#[warn(deprecated)]` on by default
 
+warning: 1 warning emitted
+