Update reporting INCONSISTENT_LANGUAGE_VERSION_OVERRIDE on part directives.

Change-Id: I100260b19d07c6ff7d172e9c31d4f99281a17807
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/155924
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>

Author: scheglov

pkg/analyzer/lib/src/dart/analysis/library_analyzer.dart

@@ -200,37 +200,41 @@ class LibraryAnalyzer {
   void _checkForInconsistentLanguageVersionOverride(
     Map<FileState, CompilationUnit> units,
   ) {
-    var libraryUnit = units.values.first;
+    var libraryEntry = units.entries.first;
+    var libraryUnit = libraryEntry.value;
     var libraryOverrideToken = libraryUnit.languageVersionToken;
 
-    for (var partEntry in units.entries.skip(1)) {
-      var partUnit = partEntry.value;
-      var partOverrideToken = partUnit.languageVersionToken;
-      if (libraryOverrideToken != null) {
-        if (partOverrideToken != null) {
-          if (partOverrideToken.major != libraryOverrideToken.major ||
-              partOverrideToken.minor != libraryOverrideToken.minor) {
-            _getErrorReporter(partEntry.key).reportErrorForToken(
-              CompileTimeErrorCode.INCONSISTENT_LANGUAGE_VERSION_OVERRIDE,
-              partOverrideToken,
-            );
+    var elementToUnit = <CompilationUnitElement, CompilationUnit>{};
+    for (var entry in units.entries) {
+      var unit = entry.value;
+      elementToUnit[unit.declaredElement] = unit;
+    }
+
+    for (var directive in libraryUnit.directives) {
+      if (directive is PartDirective) {
+        var partUnit = elementToUnit[directive.uriElement];
+        if (partUnit != null) {
+          var shouldReport = false;
+          var partOverrideToken = partUnit.languageVersionToken;
+          if (libraryOverrideToken != null) {
+            if (partOverrideToken != null) {
+              if (partOverrideToken.major != libraryOverrideToken.major ||
+                  partOverrideToken.minor != libraryOverrideToken.minor) {
+                shouldReport = true;
+              }
+            } else {
+              shouldReport = true;
+            }
+          } else if (partOverrideToken != null) {
+            shouldReport = true;
           }
-        } else {
-          var partDirectives = partUnit.directives;
-          for (var partOf in partDirectives.whereType<PartOfDirective>()) {
-            var partOffset = partOf.partKeyword.offset;
-            _getErrorReporter(partEntry.key).reportErrorForOffset(
+          if (shouldReport) {
+            _getErrorReporter(_library).reportErrorForNode(
               CompileTimeErrorCode.INCONSISTENT_LANGUAGE_VERSION_OVERRIDE,
-              partOffset,
-              partOf.ofKeyword.end - partOffset,
+              directive.uri,
             );
           }
         }
-      } else if (partOverrideToken != null) {
-        _getErrorReporter(partEntry.key).reportErrorForToken(
-          CompileTimeErrorCode.INCONSISTENT_LANGUAGE_VERSION_OVERRIDE,
-          partOverrideToken,
-        );
       }
     }
   }

pkg/analyzer/test/src/diagnostics/inconsistent_language_version_override_test.dart

@@ -30,8 +30,8 @@ part 'b.dart';
 // @dart = 2.6
 part of 'a.dart';
 ''',
-      partErrors: [
-        error(_errorCode, 0, 14),
+      libraryErrors: [
+        error(_errorCode, 20, 8),
       ],
     );
   }
@@ -46,7 +46,7 @@ part 'b.dart';
 // @dart = 2.5
 part of 'a.dart';
 ''',
-      partErrors: [],
+      libraryErrors: [],
     );
   }
 
@@ -58,7 +58,7 @@ part 'b.dart';
       partContent: r'''
 part of 'a.dart';
 ''',
-      partErrors: [],
+      libraryErrors: [],
     );
   }
 
@@ -71,8 +71,8 @@ part 'b.dart';
       partContent: r'''
 part of 'a.dart';
 ''',
-      partErrors: [
-        error(_errorCode, 0, 7),
+      libraryErrors: [
+        error(_errorCode, 20, 8),
       ],
     );
   }
@@ -86,16 +86,16 @@ part 'b.dart';
 // @dart = 2.5
 part of 'a.dart';
 ''',
-      partErrors: [
-        error(_errorCode, 0, 14),
+      libraryErrors: [
+        error(_errorCode, 5, 8),
       ],
     );
   }
 
   Future<void> _checkLibraryAndPart({
     @required String libraryContent,
     @required String partContent,
-    @required List<ExpectedError> partErrors,
+    @required List<ExpectedError> libraryErrors,
   }) async {
     var libraryPath = convertPath('/test/lib/a.dart');
     var partPath = convertPath('/test/lib/b.dart');
@@ -104,8 +104,6 @@ part of 'a.dart';
 
     newFile(partPath, content: partContent);
 
-    await resolveFile(libraryPath);
-
-    await assertErrorsInFile2(partPath, partErrors);
+    await assertErrorsInFile2(libraryPath, libraryErrors);
   }
 }