From c1a98416e3e615e2d195a05eec4bad4705c9fc95 Mon Sep 17 00:00:00 2001
From: finalchild <finalchild2@gmail.com>
Date: Wed, 17 Aug 2022 05:07:47 +0900
Subject: [PATCH] Migrate emoji identifier diagnostics to `SessionDiagnostic`

---
 Cargo.lock                                    |  1 +
 .../locales/en-US/interface.ftl               |  6 +++
 compiler/rustc_error_messages/src/lib.rs      |  1 +
 compiler/rustc_interface/Cargo.toml           |  1 +
 compiler/rustc_interface/src/passes.rs        | 40 ++++++++++---------
 5 files changed, 31 insertions(+), 18 deletions(-)
 create mode 100644 compiler/rustc_error_messages/locales/en-US/interface.ftl

diff --git a/Cargo.lock b/Cargo.lock
index 395f5a127bd3d..c2799e39fd30c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4011,6 +4011,7 @@ dependencies = [
  "rustc_hir",
  "rustc_incremental",
  "rustc_lint",
+ "rustc_macros",
  "rustc_metadata",
  "rustc_middle",
  "rustc_mir_build",
diff --git a/compiler/rustc_error_messages/locales/en-US/interface.ftl b/compiler/rustc_error_messages/locales/en-US/interface.ftl
new file mode 100644
index 0000000000000..2c05abd8c0996
--- /dev/null
+++ b/compiler/rustc_error_messages/locales/en-US/interface.ftl
@@ -0,0 +1,6 @@
+interface_ferris_identifier =
+    Ferris cannot be used as an identifier
+    .suggestion = try using their name instead
+
+interface_emoji_identifier =
+    identifiers cannot contain emoji: `{$ident}`
diff --git a/compiler/rustc_error_messages/src/lib.rs b/compiler/rustc_error_messages/src/lib.rs
index 9e73a39980927..6ae4dab3a35eb 100644
--- a/compiler/rustc_error_messages/src/lib.rs
+++ b/compiler/rustc_error_messages/src/lib.rs
@@ -34,6 +34,7 @@ fluent_messages! {
     builtin_macros => "../locales/en-US/builtin_macros.ftl",
     const_eval => "../locales/en-US/const_eval.ftl",
     expand => "../locales/en-US/expand.ftl",
+    interface => "../locales/en-US/interface.ftl",
     lint => "../locales/en-US/lint.ftl",
     parser => "../locales/en-US/parser.ftl",
     passes => "../locales/en-US/passes.ftl",
diff --git a/compiler/rustc_interface/Cargo.toml b/compiler/rustc_interface/Cargo.toml
index 1ecbc876c8d8a..da4002d09ad02 100644
--- a/compiler/rustc_interface/Cargo.toml
+++ b/compiler/rustc_interface/Cargo.toml
@@ -17,6 +17,7 @@ rustc_attr = { path = "../rustc_attr" }
 rustc_borrowck = { path = "../rustc_borrowck" }
 rustc_builtin_macros = { path = "../rustc_builtin_macros" }
 rustc_expand = { path = "../rustc_expand" }
+rustc_macros = { path = "../rustc_macros" }
 rustc_parse = { path = "../rustc_parse" }
 rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index 8f0835917861a..e00d0b7d0d82f 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -8,11 +8,12 @@ use rustc_borrowck as mir_borrowck;
 use rustc_codegen_ssa::traits::CodegenBackend;
 use rustc_data_structures::parallel;
 use rustc_data_structures::sync::{Lrc, OnceCell, WorkerLocal};
-use rustc_errors::{Applicability, ErrorGuaranteed, MultiSpan, PResult};
+use rustc_errors::{ErrorGuaranteed, PResult};
 use rustc_expand::base::{ExtCtxt, LintStoreExpand, ResolverExpand};
 use rustc_hir::def_id::StableCrateId;
 use rustc_hir::definitions::Definitions;
 use rustc_lint::{BufferedEarlyLint, EarlyCheckNode, LintStore};
+use rustc_macros::SessionDiagnostic;
 use rustc_metadata::creader::CStore;
 use rustc_middle::arena::Arena;
 use rustc_middle::dep_graph::DepGraph;
@@ -30,7 +31,7 @@ use rustc_session::output::filename_for_input;
 use rustc_session::search_paths::PathKind;
 use rustc_session::{Limit, Session};
 use rustc_span::symbol::{sym, Symbol};
-use rustc_span::FileName;
+use rustc_span::{FileName, Span};
 use rustc_trait_selection::traits;
 use rustc_typeck as typeck;
 use tracing::{info, warn};
@@ -263,6 +264,23 @@ impl LintStoreExpand for LintStoreExpandImpl<'_> {
     }
 }
 
+#[derive(SessionDiagnostic)]
+#[error(interface::ferris_identifier)]
+struct FerrisIdentifier {
+    #[primary_span]
+    spans: Vec<Span>,
+    #[suggestion(code = "ferris", applicability = "maybe-incorrect")]
+    first_span: Span,
+}
+
+#[derive(SessionDiagnostic)]
+#[error(interface::emoji_identifier)]
+struct EmojiIdentifier {
+    #[primary_span]
+    spans: Vec<Span>,
+    ident: Symbol,
+}
+
 /// Runs the "early phases" of the compiler: initial `cfg` processing, loading compiler plugins,
 /// syntax expansion, secondary `cfg` expansion, synthesis of a test
 /// harness if one is to be provided, injection of a dependency on the
@@ -443,23 +461,9 @@ pub fn configure_and_expand(
             spans.sort();
             if ident == sym::ferris {
                 let first_span = spans[0];
-                sess.diagnostic()
-                    .struct_span_err(
-                        MultiSpan::from(spans),
-                        "Ferris cannot be used as an identifier",
-                    )
-                    .span_suggestion(
-                        first_span,
-                        "try using their name instead",
-                        "ferris",
-                        Applicability::MaybeIncorrect,
-                    )
-                    .emit();
+                sess.emit_err(FerrisIdentifier { spans, first_span });
             } else {
-                sess.diagnostic().span_err(
-                    MultiSpan::from(spans),
-                    &format!("identifiers cannot contain emoji: `{}`", ident),
-                );
+                sess.emit_err(EmojiIdentifier { spans, ident });
             }
         }
     });