[messages] Change analyzerCodes into a list of enums.

Changes the representation of analyzer codes in the `Codes` class from
a `List<String>` to a `List<AnalyzerCode>`, where `AnalyzerCode` is a
generated enum.

This has two major benefits:

- It allows switch statements acting on analyzer codes to be more
  efficient, since they don't have to do string comparisons.

- It allows unnecessary cases to be safely removed from switch
  statements acting on analyzer codes, since it is now clear from the
  type system what possible values an AnalyzerCode can take
  on. Several unnecessary cases are removed in this CL.

Change-Id: I6a6a696463848ece8db2a34fa65ddd5cf0dc8f0c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/449920
Reviewed-by: Konstantin Shcheglov <[email protected]>
Reviewed-by: Johnni Winther <[email protected]>
Commit-Queue: Paul Berry <[email protected]>

Author: stereotype441

pkg/_fe_analyzer_shared/lib/src/messages/codes.dart

@@ -28,7 +28,7 @@ class Code {
   /// this error to its corresponding Analyzer error.
   final int index;
 
-  final List<String>? analyzerCodes;
+  final List<AnalyzerCode>? analyzerCodes;
 
   final CfeSeverity severity;
 

pkg/_fe_analyzer_shared/lib/src/messages/codes_generated.dart

@@ -31,7 +31,7 @@ void translateErrorToken(ErrorToken token, ReportError reportError) {
 
   Code errorCode = token.errorCode;
   switch (errorCode.analyzerCodes?.first) {
-    case "UNTERMINATED_STRING_LITERAL":
+    case AnalyzerCode.unterminatedStringLiteral:
       // TODO(paulberry,ahe): Fasta reports the error location as the entire
       // string; analyzer expects the end of the string.
       reportError(
@@ -41,7 +41,7 @@ void translateErrorToken(ErrorToken token, ReportError reportError) {
       );
       return;
 
-    case "UNTERMINATED_MULTI_LINE_COMMENT":
+    case AnalyzerCode.unterminatedMultiLineComment:
       // TODO(paulberry,ahe): Fasta reports the error location as the entire
       // comment; analyzer expects the end of the comment.
       reportError(
@@ -51,27 +51,27 @@ void translateErrorToken(ErrorToken token, ReportError reportError) {
       );
       return;
 
-    case "MISSING_DIGIT":
+    case AnalyzerCode.missingDigit:
       // TODO(paulberry,ahe): Fasta reports the error location as the entire
       // number; analyzer expects the end of the number.
       charOffset = endOffset - 1;
       return _makeError(ScannerErrorCode.missingDigit, null);
 
-    case "MISSING_HEX_DIGIT":
+    case AnalyzerCode.missingHexDigit:
       // TODO(paulberry,ahe): Fasta reports the error location as the entire
       // number; analyzer expects the end of the number.
       charOffset = endOffset - 1;
       return _makeError(ScannerErrorCode.missingHexDigit, null);
 
-    case "ILLEGAL_CHARACTER":
+    case AnalyzerCode.illegalCharacter:
       // We can safely assume `token.character` is non-`null` because this error
       // is only reported when there is a character associated with the token.
       return _makeError(ScannerErrorCode.illegalCharacter, [token.character!]);
 
-    case "UNEXPECTED_SEPARATOR_IN_NUMBER":
+    case AnalyzerCode.unexpectedSeparatorInNumber:
       return _makeError(ScannerErrorCode.unexpectedSeparatorInNumber, null);
 
-    case "UNSUPPORTED_OPERATOR":
+    case AnalyzerCode.unsupportedOperator:
       return _makeError(ScannerErrorCode.unsupportedOperator, [
         (token as UnsupportedOperator).token.lexeme,
       ]);

pkg/_fe_analyzer_shared/lib/src/scanner/errors.dart

@@ -30,7 +30,8 @@ import 'package:_fe_analyzer_shared/src/messages/codes.dart'
         codeExpectedIdentifier,
         codeExperimentNotEnabled,
         codeExtraneousModifier,
-        codeInternalProblemUnhandled;
+        codeInternalProblemUnhandled,
+        AnalyzerCode;
 import 'package:_fe_analyzer_shared/src/parser/parser.dart'
     show
         Assert,
@@ -223,7 +224,7 @@ class AstBuilder extends StackListener {
   }) {
     if (directives.isEmpty &&
         (message.code.analyzerCodes?.contains(
-              'NON_PART_OF_DIRECTIVE_IN_PART',
+              AnalyzerCode.nonPartOfDirectiveInPart,
             ) ??
             false)) {
       message = codeDirectiveAfterDeclaration;