refactor away from derives and use span_suggestion() instead. Show's the correct(?) generic contents, but overwrites the fn name :(

Author: spanishpear

compiler/rustc_parse/src/errors.rs

@@ -883,13 +883,13 @@ pub(crate) struct SuggRemoveComma {
 }
 
 //TODO: SHREYS - should this be help, or a suggestion?
-#[derive(Subdiagnostic)]
-pub(crate) struct SuggMisplacedGeneric {
-    pub snippet: String,
-    #[suggestion(code = "<{snippet}>")]
-    #[primary_span]
-    pub span: Span,
-}
+// #[derive(Subdiagnostic)]
+// pub(crate) struct SuggMisplacedGeneric {
+//     pub snippet: String,
+//     #[suggestion(code = "<{snippet}>")]
+//     #[primary_span]
+//     pub span: Span,
+// }
 
 #[derive(Subdiagnostic)]
 pub(crate) enum ExpectedIdentifierFound {
@@ -924,7 +924,6 @@ pub(crate) struct ExpectedIdentifier {
     pub token: Token,
     pub suggest_raw: Option<SuggEscapeToUseAsIdentifier>,
     pub suggest_remove_comma: Option<SuggRemoveComma>,
-    pub suggest_misplaced_generic: Option<SuggMisplacedGeneric>,
 }
 
 impl<'a, G: EmissionGuarantee> IntoDiagnostic<'a, G> for ExpectedIdentifier {
@@ -954,9 +953,6 @@ impl<'a, G: EmissionGuarantee> IntoDiagnostic<'a, G> for ExpectedIdentifier {
             sugg.add_to_diagnostic(&mut diag);
         }
 
-        if let Some(sugg) = self.suggest_misplaced_generic {
-            sugg.add_to_diagnostic(&mut diag);
-        }
 
         ExpectedIdentifierFound::new(token_descr, self.span).add_to_diagnostic(&mut diag);
 

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -12,7 +12,7 @@ use crate::errors::{
     IncorrectAwait, IncorrectSemicolon, IncorrectUseOfAwait, ParenthesesInForHead,
     ParenthesesInForHeadSugg, PatternMethodParamWithoutBody, QuestionMarkInType,
     QuestionMarkInTypeSugg, SelfParamNotFirst, StructLiteralBodyWithoutPath,
-    StructLiteralBodyWithoutPathSugg, SuggEscapeToUseAsIdentifier, SuggMisplacedGeneric,
+    StructLiteralBodyWithoutPathSugg, SuggEscapeToUseAsIdentifier,
     SuggRemoveComma, UnexpectedConstInGenericParam, UnexpectedConstParamDeclaration,
     UnexpectedConstParamDeclarationSugg, UnmatchedAngleBrackets, UseEqInstead,
 };
@@ -326,38 +326,41 @@ impl<'a> Parser<'a> {
                 None
             };
 
-        let span = self.token.span;
-        let token = self.token.clone();
-        let suggest_misplaced_generic = if self.token == token::Lt {
-            // store the span before the generic calculation starts
-            self.parse_generics().map_or(None, |generic| {
-                // at this point, token should be Ident with the fn name
-
-                // FIXME: shreys the span should be the span of where the gneeric SHOULD go.
-                // TODO: shreys what does this look like with invalid generic
-                // TODO: shreys - what to do if no snippet? probably just HELP not suggestion
-
-                let snippet = match self.sess.source_map().span_to_snippet(generic.span) {
-                    Ok(snippet) => snippet, 
-                    _ => "".to_string()
-                };
-                
-                Some(SuggMisplacedGeneric { span: self.token.span.to(generic.span.shrink_to_hi()), snippet })
-            })
-
-        } else {
-            None
-        };
-
-        // FIXME: write better rust
+        // FIXME: shreys write better rust
         let err = ExpectedIdentifier {
-            span: if suggest_misplaced_generic.is_some() { span } else { self.token.span },
-            token: if suggest_misplaced_generic.is_some() { token } else { self.token.clone() },
+            span: self.token.span ,
+            token: self.token.clone(),
             suggest_raw,
             suggest_remove_comma,
-            suggest_misplaced_generic,
         };
-        err.into_diagnostic(&self.sess.span_diagnostic)
+        let mut err = err.into_diagnostic(&self.sess.span_diagnostic);
+
+        if self.token == token::Lt {
+            // HACK: shreys shut the compiler up about unused result
+            let _ = self.parse_generics()
+                .map(|generic| {
+                    // at this point, token should be Ident with the fn name
+
+                    // FIXME: shreys the span should be the span of where the gneeric SHOULD go.
+                    // TODO: shreys what does this look like with invalid generic
+                    // TODO: shreys - what to do if no snippet? probably just HELP not suggestion
+
+                    let snippet = match self.sess.source_map().span_to_snippet(generic.span) {
+                        Ok(snippet) => snippet, 
+                        _ => "".to_string()
+                    };
+                    
+                    err.span_suggestion(
+                        self.token.span.to(generic.span.shrink_to_hi()),
+                        "help: place the generic parameter list after the function name:",
+                        snippet,
+                        Applicability::MachineApplicable
+                    );
+                });
+        } 
+
+        err
+
     }
 
     pub(super) fn expected_one_of_not_found(