Add `level` arg to `into_diagnostic`.

And make all hand-written `IntoDiagnostic` impls generic, by using
`DiagnosticBuilder::new(dcx, level, ...)` instead of e.g.
`dcx.struct_err(...)`.

This means the `create_*` functions are the source of the error level.
This change will let us remove `struct_diagnostic`.

Note: `#[rustc_lint_diagnostics]` is added to `DiagnosticBuilder::new`,
it's necessary to pass diagnostics tests now that it's used in
`into_diagnostic` functions.

1 files changed, 12 insertions, 19 deletions

diff --git a/compiler/rustc_metadata/src/errors.rs b/compiler/rustc_metadata/src/errors.rs
index 206c15edd78..e13068cb6f9 100644
--- a/compiler/rustc_metadata/src/errors.rs
+++ b/compiler/rustc_metadata/src/errors.rs
@@ -3,7 +3,9 @@ use std::{
     path::{Path, PathBuf},
 };
 
-use rustc_errors::{error_code, ErrorGuaranteed, IntoDiagnostic};
+use rustc_errors::{
+    error_code, DiagCtxt, DiagnosticBuilder, EmissionGuarantee, IntoDiagnostic, Level,
+};
 use rustc_macros::Diagnostic;
 use rustc_session::config;
 use rustc_span::{sym, Span, Symbol};
@@ -495,12 +497,9 @@ pub(crate) struct MultipleCandidates {
     pub candidates: Vec<PathBuf>,
 }
 
-impl IntoDiagnostic<'_> for MultipleCandidates {
-    fn into_diagnostic(
-        self,
-        dcx: &'_ rustc_errors::DiagCtxt,
-    ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> {
-        let mut diag = dcx.struct_err(fluent::metadata_multiple_candidates);
+impl<G: EmissionGuarantee> IntoDiagnostic<'_, G> for MultipleCandidates {
+    fn into_diagnostic(self, dcx: &'_ DiagCtxt, level: Level) -> DiagnosticBuilder<'_, G> {
+        let mut diag = DiagnosticBuilder::new(dcx, level, fluent::metadata_multiple_candidates);
         diag.set_arg("crate_name", self.crate_name);
         diag.set_arg("flavor", self.flavor);
         diag.code(error_code!(E0464));
@@ -593,13 +592,10 @@ pub struct InvalidMetadataFiles {
     pub crate_rejections: Vec<String>,
 }
 
-impl IntoDiagnostic<'_> for InvalidMetadataFiles {
+impl<G: EmissionGuarantee> IntoDiagnostic<'_, G> for InvalidMetadataFiles {
     #[track_caller]
-    fn into_diagnostic(
-        self,
-        dcx: &'_ rustc_errors::DiagCtxt,
-    ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> {
-        let mut diag = dcx.struct_err(fluent::metadata_invalid_meta_files);
+    fn into_diagnostic(self, dcx: &'_ DiagCtxt, level: Level) -> DiagnosticBuilder<'_, G> {
+        let mut diag = DiagnosticBuilder::new(dcx, level, fluent::metadata_invalid_meta_files);
         diag.set_arg("crate_name", self.crate_name);
         diag.set_arg("add_info", self.add_info);
         diag.code(error_code!(E0786));
@@ -623,13 +619,10 @@ pub struct CannotFindCrate {
     pub is_ui_testing: bool,
 }
 
-impl IntoDiagnostic<'_> for CannotFindCrate {
+impl<G: EmissionGuarantee> IntoDiagnostic<'_, G> for CannotFindCrate {
     #[track_caller]
-    fn into_diagnostic(
-        self,
-        dcx: &'_ rustc_errors::DiagCtxt,
-    ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> {
-        let mut diag = dcx.struct_err(fluent::metadata_cannot_find_crate);
+    fn into_diagnostic(self, dcx: &'_ DiagCtxt, level: Level) -> DiagnosticBuilder<'_, G> {
+        let mut diag = DiagnosticBuilder::new(dcx, level, fluent::metadata_cannot_find_crate);
         diag.set_arg("crate_name", self.crate_name);
         diag.set_arg("current_crate", self.current_crate);
         diag.set_arg("add_info", self.add_info);