Rollup merge of #120840 - HTGAzureX1212:HTGAzureX1212/unicode-identifier-types, r=fmease,Manishearth

Split Diagnostics for Uncommon Codepoints: Add Individual Identifier Types

This pull request further modifies the `uncommon_codepoints` lint, adding the individual identifier types of `Technical`, `Not_NFKC`, `Exclusion` and `Limited_Use` to the diagnostic message.

Example rendered diagnostic:
```
error: identifier contains a Unicode codepoint that is not used in normalized strings: 'ij'
  --> $DIR/lint-uncommon-codepoints.rs:6:4
   |
LL | fn dijkstra() {}
   |    ^^^^^^^
   = note: this character is included in the Not_NFKC Unicode general security profile
```

Second step of #120228.

compiler/rustc_lint/messages.ftl

@@ -244,9 +244,28 @@ lint_hidden_unicode_codepoints = unicode codepoint changing visible direction of
 lint_identifier_non_ascii_char = identifier contains non-ASCII characters
 
 lint_identifier_uncommon_codepoints = identifier contains {$codepoints_len ->
-    [one] an uncommon Unicode codepoint
-    *[other] uncommon Unicode codepoints
+    [one] { $identifier_type ->
+        [Exclusion] a character from an archaic script
+        [Technical] a character that is for non-linguistic, specialized usage
+        [Limited_Use] a character from a script in limited use
+        [Not_NFKC] a non normalized (NFKC) character
+        *[other] an uncommon character
+    }
+    *[other] { $identifier_type ->
+        [Exclusion] {$codepoints_len} characters from archaic scripts
+        [Technical] {$codepoints_len} characters that are for non-linguistic, specialized usage
+        [Limited_Use] {$codepoints_len} characters from scripts in limited use
+        [Not_NFKC] {$codepoints_len} non normalized (NFKC) characters
+        *[other] uncommon characters
+    }
 }: {$codepoints}
+    .note = {$codepoints_len ->
+        [one] this character is
+        *[other] these characters are
+    } included in the{$identifier_type ->
+        [Restricted] {""}
+        *[other] {" "}{$identifier_type}
+    } Unicode general security profile
 
 lint_ignored_unless_crate_specified = {$level}({$name}) is ignored unless specified at crate level
 

compiler/rustc_lint/src/lib.rs

@@ -31,6 +31,7 @@
 #![feature(array_windows)]
 #![feature(box_patterns)]
 #![feature(control_flow_enum)]
+#![feature(extract_if)]
 #![feature(generic_nonzero)]
 #![feature(if_let_guard)]
 #![feature(iter_order_by)]

compiler/rustc_lint/src/lints.rs

@@ -1129,9 +1129,11 @@ pub struct IdentifierNonAsciiChar;
 
 #[derive(LintDiagnostic)]
 #[diag(lint_identifier_uncommon_codepoints)]
+#[note]
 pub struct IdentifierUncommonCodepoints {
     pub codepoints: Vec<char>,
     pub codepoints_len: usize,
+    pub identifier_type: &'static str,
 }
 
 #[derive(LintDiagnostic)]

compiler/rustc_lint/src/non_ascii_idents.rs

@@ -7,6 +7,7 @@ use rustc_ast as ast;
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::unord::UnordMap;
 use rustc_span::symbol::Symbol;
+use unicode_security::general_security_profile::IdentifierType;
 
 declare_lint! {
     /// The `non_ascii_idents` lint detects non-ASCII identifiers.
@@ -189,17 +190,47 @@ impl EarlyLintPass for NonAsciiIdents {
             if check_uncommon_codepoints
                 && !symbol_str.chars().all(GeneralSecurityProfile::identifier_allowed)
             {
-                let codepoints: Vec<_> = symbol_str
+                let mut chars: Vec<_> = symbol_str
                     .chars()
-                    .filter(|c| !GeneralSecurityProfile::identifier_allowed(*c))
+                    .map(|c| (c, GeneralSecurityProfile::identifier_type(c)))
                     .collect();
-                let codepoints_len = codepoints.len();
 
-                cx.emit_span_lint(
-                    UNCOMMON_CODEPOINTS,
-                    sp,
-                    IdentifierUncommonCodepoints { codepoints, codepoints_len },
-                );
+                for (id_ty, id_ty_descr) in [
+                    (IdentifierType::Exclusion, "Exclusion"),
+                    (IdentifierType::Technical, "Technical"),
+                    (IdentifierType::Limited_Use, "Limited_Use"),
+                    (IdentifierType::Not_NFKC, "Not_NFKC"),
+                ] {
+                    let codepoints: Vec<_> =
+                        chars.extract_if(|(_, ty)| *ty == Some(id_ty)).collect();
+                    if codepoints.is_empty() {
+                        continue;
+                    }
+                    cx.emit_span_lint(
+                        UNCOMMON_CODEPOINTS,
+                        sp,
+                        IdentifierUncommonCodepoints {
+                            codepoints_len: codepoints.len(),
+                            codepoints: codepoints.into_iter().map(|(c, _)| c).collect(),
+                            identifier_type: id_ty_descr,
+                        },
+                    );
+                }
+
+                let remaining = chars
+                    .extract_if(|(c, _)| !GeneralSecurityProfile::identifier_allowed(*c))
+                    .collect::<Vec<_>>();
+                if !remaining.is_empty() {
+                    cx.emit_span_lint(
+                        UNCOMMON_CODEPOINTS,
+                        sp,
+                        IdentifierUncommonCodepoints {
+                            codepoints_len: remaining.len(),
+                            codepoints: remaining.into_iter().map(|(c, _)| c).collect(),
+                            identifier_type: "Restricted",
+                        },
+                    );
+                }
             }
         }