Rollup merge of #101434 - JhonnyBillM:replace-session-for-handler-in-into-diagnostic, r=davidtwco

Update `SessionDiagnostic::into_diagnostic` to take `Handler` instead of `ParseSess`

Suggested by the team in [this Zulip Topic](https://rust-lang.zulipchat.com/#narrow/stream/336883-i18n/topic/.23100717.20SessionDiagnostic.20on.20Handler).

`Handler` already has almost all the capabilities of `ParseSess` when it comes to diagnostic emission, in this migration we only needed to add the ability to access `source_map` from the emitter in order to get a `Snippet` and the `start_point`. Not sure if adding these two methods [`span_to_snippet_from_emitter` and  `span_start_point_from_emitter`] is the best way to address this gap.

P.S. If this goes in the right direction, then we probably may want to move `SessionDiagnostic` to `rustc_errors` and rename it to `DiagnosticHandler` or something similar.

r? `@davidtwco`
r? `@compiler-errors`

2 files changed, 26 insertions, 24 deletions

diff --git a/src/test/ui-fulldeps/internal-lints/diagnostics.rs b/src/test/ui-fulldeps/internal-lints/diagnostics.rs
index 0e449256153..e9e809fa416 100644
--- a/src/test/ui-fulldeps/internal-lints/diagnostics.rs
+++ b/src/test/ui-fulldeps/internal-lints/diagnostics.rs
@@ -11,9 +11,11 @@ extern crate rustc_macros;
 extern crate rustc_session;
 extern crate rustc_span;
 
-use rustc_errors::{AddSubdiagnostic, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, fluent};
+use rustc_errors::{
+    AddSubdiagnostic, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, Handler, fluent
+};
 use rustc_macros::{SessionDiagnostic, SessionSubdiagnostic};
-use rustc_session::{parse::ParseSess, SessionDiagnostic};
+use rustc_session::SessionDiagnostic;
 use rustc_span::Span;
 
 #[derive(SessionDiagnostic)]
@@ -33,8 +35,8 @@ struct Note {
 pub struct UntranslatableInSessionDiagnostic;
 
 impl<'a> SessionDiagnostic<'a, ErrorGuaranteed> for UntranslatableInSessionDiagnostic {
-    fn into_diagnostic(self, sess: &'a ParseSess) -> DiagnosticBuilder<'a, ErrorGuaranteed> {
-        sess.struct_err("untranslatable diagnostic")
+    fn into_diagnostic(self, handler: &'a Handler) -> DiagnosticBuilder<'a, ErrorGuaranteed> {
+        handler.struct_err("untranslatable diagnostic")
         //~^ ERROR diagnostics should be created using translatable messages
     }
 }
@@ -42,8 +44,8 @@ impl<'a> SessionDiagnostic<'a, ErrorGuaranteed> for UntranslatableInSessionDiagn
 pub struct TranslatableInSessionDiagnostic;
 
 impl<'a> SessionDiagnostic<'a, ErrorGuaranteed> for TranslatableInSessionDiagnostic {
-    fn into_diagnostic(self, sess: &'a ParseSess) -> DiagnosticBuilder<'a, ErrorGuaranteed> {
-        sess.struct_err(fluent::parser::expect_path)
+    fn into_diagnostic(self, handler: &'a Handler) -> DiagnosticBuilder<'a, ErrorGuaranteed> {
+        handler.struct_err(fluent::parser::expect_path)
     }
 }
 
@@ -64,11 +66,11 @@ impl AddSubdiagnostic for TranslatableInAddSubdiagnostic {
     }
 }
 
-pub fn make_diagnostics<'a>(sess: &'a ParseSess) {
-    let _diag = sess.struct_err(fluent::parser::expect_path);
+pub fn make_diagnostics<'a>(handler: &'a Handler) {
+    let _diag = handler.struct_err(fluent::parser::expect_path);
     //~^ ERROR diagnostics should only be created in `SessionDiagnostic`/`AddSubdiagnostic` impls
 
-    let _diag = sess.struct_err("untranslatable diagnostic");
+    let _diag = handler.struct_err("untranslatable diagnostic");
     //~^ ERROR diagnostics should only be created in `SessionDiagnostic`/`AddSubdiagnostic` impls
     //~^^ ERROR diagnostics should be created using translatable messages
 }
@@ -76,6 +78,6 @@ pub fn make_diagnostics<'a>(sess: &'a ParseSess) {
 // Check that `rustc_lint_diagnostics`-annotated functions aren't themselves linted.
 
 #[rustc_lint_diagnostics]
-pub fn skipped_because_of_annotation<'a>(sess: &'a ParseSess) {
-    let _diag = sess.struct_err("untranslatable diagnostic"); // okay!
+pub fn skipped_because_of_annotation<'a>(handler: &'a Handler) {
+    let _diag = handler.struct_err("untranslatable diagnostic"); // okay!
 }
diff --git a/src/test/ui-fulldeps/internal-lints/diagnostics.stderr b/src/test/ui-fulldeps/internal-lints/diagnostics.stderr
index ed5105dabcd..e5c5bc2e998 100644
--- a/src/test/ui-fulldeps/internal-lints/diagnostics.stderr
+++ b/src/test/ui-fulldeps/internal-lints/diagnostics.stderr
@@ -1,8 +1,8 @@
 error: diagnostics should be created using translatable messages
-  --> $DIR/diagnostics.rs:37:14
+  --> $DIR/diagnostics.rs:39:17
    |
-LL |         sess.struct_err("untranslatable diagnostic")
-   |              ^^^^^^^^^^
+LL |         handler.struct_err("untranslatable diagnostic")
+   |                 ^^^^^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/diagnostics.rs:6:9
@@ -11,16 +11,16 @@ LL | #![deny(rustc::untranslatable_diagnostic)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostics should be created using translatable messages
-  --> $DIR/diagnostics.rs:54:14
+  --> $DIR/diagnostics.rs:56:14
    |
 LL |         diag.note("untranslatable diagnostic");
    |              ^^^^
 
 error: diagnostics should only be created in `SessionDiagnostic`/`AddSubdiagnostic` impls
-  --> $DIR/diagnostics.rs:68:22
+  --> $DIR/diagnostics.rs:70:25
    |
-LL |     let _diag = sess.struct_err(fluent::parser::expect_path);
-   |                      ^^^^^^^^^^
+LL |     let _diag = handler.struct_err(fluent::parser::expect_path);
+   |                         ^^^^^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/diagnostics.rs:7:9
@@ -29,16 +29,16 @@ LL | #![deny(rustc::diagnostic_outside_of_impl)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostics should only be created in `SessionDiagnostic`/`AddSubdiagnostic` impls
-  --> $DIR/diagnostics.rs:71:22
+  --> $DIR/diagnostics.rs:73:25
    |
-LL |     let _diag = sess.struct_err("untranslatable diagnostic");
-   |                      ^^^^^^^^^^
+LL |     let _diag = handler.struct_err("untranslatable diagnostic");
+   |                         ^^^^^^^^^^
 
 error: diagnostics should be created using translatable messages
-  --> $DIR/diagnostics.rs:71:22
+  --> $DIR/diagnostics.rs:73:25
    |
-LL |     let _diag = sess.struct_err("untranslatable diagnostic");
-   |                      ^^^^^^^^^^
+LL |     let _diag = handler.struct_err("untranslatable diagnostic");
+   |                         ^^^^^^^^^^
 
 error: aborting due to 5 previous errors