Auto merge of rust-lang#113281 - dayo05:master, r=davidtwco

Implement diagnostic translation for rustc-errors

This is my first PR to rustc yeah~

I'm going to implement diagnostic translation on rustc-errors crate.

This PR is WIP, the reason of opening this as draft, I want to show my code to prevent the issue caused by misunderstanding and also I have few questions.

Some error messages are processed by `pluralize!` macro which determines to use plural word or not. From now, I make two kinds of keys and combine with enum but I'm not sure is this best method to do it.

Is there any prefered method to do this? => This resolved on conversation on PR.

I'll remain to perform force-push until my first implementation looks good to me

Author: bors

compiler/rustc_errors/messages.ftl

@@ -1,3 +1,25 @@
+errors_delayed_at_with_newline =
+    delayed at {$emitted_at}
+    {$note}
+
+errors_delayed_at_without_newline =
+    delayed at {$emitted_at} - {$note}
+
+errors_expected_lifetime_parameter =
+    expected lifetime {$count ->
+        [1] parameter
+        *[other] parameters
+    }
+
+errors_indicate_anonymous_lifetime =
+    indicate the anonymous {$count ->
+        [1] lifetime
+        *[other] lifetimes
+    }
+
+errors_invalid_flushed_delayed_diagnostic_level =
+    `flushed_delayed` got diagnostic with level {$level}, instead of the expected `DelayedBug`
+
 errors_target_inconsistent_architecture =
     inconsistent target specification: "data-layout" claims architecture is {$dl}-endian, while "target-endian" is `{$target}`
 

compiler/rustc_errors/src/diagnostic_impls.rs

@@ -1,3 +1,4 @@
+use crate::diagnostic::DiagnosticLocation;
 use crate::{fluent_generated as fluent, AddToDiagnostic};
 use crate::{DiagnosticArgValue, DiagnosticBuilder, Handler, IntoDiagnostic, IntoDiagnosticArg};
 use rustc_ast as ast;
@@ -10,6 +11,7 @@ use rustc_span::Span;
 use rustc_target::abi::TargetDataLayoutErrors;
 use rustc_target::spec::{PanicStrategy, SplitDebuginfo, StackProtector, TargetTriple};
 use rustc_type_ir as type_ir;
+use std::backtrace::Backtrace;
 use std::borrow::Cow;
 use std::fmt;
 use std::num::ParseIntError;
@@ -317,3 +319,62 @@ pub enum LabelKind {
     Label,
     Help,
 }
+
+#[derive(Subdiagnostic)]
+#[label(errors_expected_lifetime_parameter)]
+pub struct ExpectedLifetimeParameter {
+    #[primary_span]
+    pub span: Span,
+    pub count: usize,
+}
+
+#[derive(Subdiagnostic)]
+#[note(errors_delayed_at_with_newline)]
+pub struct DelayedAtWithNewline {
+    #[primary_span]
+    pub span: Span,
+    pub emitted_at: DiagnosticLocation,
+    pub note: Backtrace,
+}
+#[derive(Subdiagnostic)]
+#[note(errors_delayed_at_without_newline)]
+pub struct DelayedAtWithoutNewline {
+    #[primary_span]
+    pub span: Span,
+    pub emitted_at: DiagnosticLocation,
+    pub note: Backtrace,
+}
+
+impl IntoDiagnosticArg for DiagnosticLocation {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+        DiagnosticArgValue::Str(Cow::from(self.to_string()))
+    }
+}
+
+impl IntoDiagnosticArg for Backtrace {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+        DiagnosticArgValue::Str(Cow::from(self.to_string()))
+    }
+}
+
+#[derive(Subdiagnostic)]
+#[note(errors_invalid_flushed_delayed_diagnostic_level)]
+pub struct InvalidFlushedDelayedDiagnosticLevel {
+    #[primary_span]
+    pub span: Span,
+    pub level: rustc_errors::Level,
+}
+impl IntoDiagnosticArg for rustc_errors::Level {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+        DiagnosticArgValue::Str(Cow::from(self.to_string()))
+    }
+}
+
+#[derive(Subdiagnostic)]
+#[suggestion(errors_indicate_anonymous_lifetime, code = "{suggestion}", style = "verbose")]
+pub struct IndicateAnonymousLifetime {
+    #[primary_span]
+    pub span: Span,
+    pub count: usize,
+    pub suggestion: String,
+}

compiler/rustc_errors/src/lib.rs

@@ -22,6 +22,8 @@ extern crate rustc_macros;
 #[macro_use]
 extern crate tracing;
 
+extern crate self as rustc_errors;
+
 pub use emitter::ColorConfig;
 
 use rustc_lint_defs::LintExpectationId;
@@ -377,13 +379,16 @@ pub struct ExplicitBug;
 /// rather than a failed assertion, etc.
 pub struct DelayedBugPanic;
 
+use crate::diagnostic_impls::{DelayedAtWithNewline, DelayedAtWithoutNewline};
 pub use diagnostic::{
     AddToDiagnostic, DecorateLint, Diagnostic, DiagnosticArg, DiagnosticArgValue, DiagnosticId,
     DiagnosticStyledString, IntoDiagnosticArg, SubDiagnostic,
 };
 pub use diagnostic_builder::{DiagnosticBuilder, EmissionGuarantee, Noted};
 pub use diagnostic_impls::{
-    DiagnosticArgFromDisplay, DiagnosticSymbolList, LabelKind, SingleLabelManySpans,
+    DiagnosticArgFromDisplay, DiagnosticSymbolList, ExpectedLifetimeParameter,
+    IndicateAnonymousLifetime, InvalidFlushedDelayedDiagnosticLevel, LabelKind,
+    SingleLabelManySpans,
 };
 use std::backtrace::{Backtrace, BacktraceStatus};
 
@@ -1673,11 +1678,10 @@ impl HandlerInner {
             if bug.level != Level::DelayedBug {
                 // NOTE(eddyb) not panicking here because we're already producing
                 // an ICE, and the more information the merrier.
-                bug.note(format!(
-                    "`flushed_delayed` got diagnostic with level {:?}, \
-                     instead of the expected `DelayedBug`",
-                    bug.level,
-                ));
+                bug.subdiagnostic(InvalidFlushedDelayedDiagnosticLevel {
+                    span: bug.span.primary_span().unwrap(),
+                    level: bug.level,
+                });
             }
             bug.level = Level::Bug;
 
@@ -1744,12 +1748,22 @@ impl DelayedDiagnostic {
     fn decorate(mut self) -> Diagnostic {
         match self.note.status() {
             BacktraceStatus::Captured => {
-                self.inner.note(format!("delayed at {}\n{}", self.inner.emitted_at, self.note));
+                let inner = &self.inner;
+                self.inner.subdiagnostic(DelayedAtWithNewline {
+                    span: inner.span.primary_span().unwrap(),
+                    emitted_at: inner.emitted_at.clone(),
+                    note: self.note,
+                });
             }
             // Avoid the needless newline when no backtrace has been captured,
             // the display impl should just be a single line.
             _ => {
-                self.inner.note(format!("delayed at {} - {}", self.inner.emitted_at, self.note));
+                let inner = &self.inner;
+                self.inner.subdiagnostic(DelayedAtWithoutNewline {
+                    span: inner.span.primary_span().unwrap(),
+                    emitted_at: inner.emitted_at.clone(),
+                    note: self.note,
+                });
             }
         }
 
@@ -1841,20 +1855,20 @@ pub fn add_elided_lifetime_in_path_suggestion(
     incl_angl_brckt: bool,
     insertion_span: Span,
 ) {
-    diag.span_label(path_span, format!("expected lifetime parameter{}", pluralize!(n)));
+    diag.subdiagnostic(ExpectedLifetimeParameter { span: path_span, count: n });
     if !source_map.is_span_accessible(insertion_span) {
         // Do not try to suggest anything if generated by a proc-macro.
         return;
     }
     let anon_lts = vec!["'_"; n].join(", ");
     let suggestion =
         if incl_angl_brckt { format!("<{}>", anon_lts) } else { format!("{}, ", anon_lts) };
-    diag.span_suggestion_verbose(
-        insertion_span.shrink_to_hi(),
-        format!("indicate the anonymous lifetime{}", pluralize!(n)),
+
+    diag.subdiagnostic(IndicateAnonymousLifetime {
+        span: insertion_span.shrink_to_hi(),
+        count: n,
         suggestion,
-        Applicability::MachineApplicable,
-    );
+    });
 }
 
 #[derive(Clone, Copy, PartialEq, Hash, Debug)]