Suppress follow-on errors when a file is imported with either a prefix or a show clause

pkg/analyzer/lib/src/dart/element/builder.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer.src.dart.element.builder;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 195 matching lines @@
     }
     return null;
   }
 
   @override
   Object visitImportDirective(ImportDirective node) {
     // Remove previous element. (It will remain null if the target is missing.)
     node.element = null;
     Source importedSource = node.source;
     int importedTime = sourceModificationTimeMap[importedSource] ?? -1;
-    if (importedTime != -1) {
-      // The imported source will be null if the URI in the import
-      // directive was invalid.
-      LibraryElement importedLibrary = importLibraryMap[importedSource];
-      if (importedLibrary != null) {
-        if (importedLibrary.isDartCore) {
-          explicitlyImportsCore = true;
+    // The imported source will be null if the URI in the import

[Brian Wilkerson, 2016/08/08 20:50:38]

I moved the test for a missing source to line 249 (new file) so that we will now
create elements even for missing files. One side effect is that we will also
create PrefixElement's for such an import, so we can now recognize more uses of
prefixes.

+    // directive was invalid.
+    LibraryElement importedLibrary = importLibraryMap[importedSource];
+    if (importedLibrary != null) {
+      if (importedLibrary.isDartCore) {
+        explicitlyImportsCore = true;
+      }
+      ImportElementImpl importElement = new ImportElementImpl(node.offset);
+      importElement.metadata = _getElementAnnotations(node.metadata);
+      StringLiteral uriLiteral = node.uri;
+      if (uriLiteral != null) {
+        importElement.uriOffset = uriLiteral.offset;
+        importElement.uriEnd = uriLiteral.end;
+      }
+      importElement.uri = node.uriContent;
+      importElement.deferred = node.deferredKeyword != null;
+      importElement.combinators = _buildCombinators(node);
+      importElement.importedLibrary = importedLibrary;
+      setElementDocumentationComment(importElement, node);
+      SimpleIdentifier prefixNode = node.prefix;
+      if (prefixNode != null) {
+        importElement.prefixOffset = prefixNode.offset;
+        String prefixName = prefixNode.name;
+        PrefixElementImpl prefix = nameToPrefixMap[prefixName];
+        if (prefix == null) {
+          prefix = new PrefixElementImpl.forNode(prefixNode);
+          nameToPrefixMap[prefixName] = prefix;
         }
-        ImportElementImpl importElement = new ImportElementImpl(node.offset);
-        importElement.metadata = _getElementAnnotations(node.metadata);
-        StringLiteral uriLiteral = node.uri;
+        importElement.prefix = prefix;
+        prefixNode.staticElement = prefix;
+      }
+      node.element = importElement;
+      imports.add(importElement);
+      if (importedTime >= 0 &&
+          importSourceKindMap[importedSource] != SourceKind.LIBRARY) {
+        int offset = node.offset;
+        int length = node.length;
         if (uriLiteral != null) {
-          importElement.uriOffset = uriLiteral.offset;
-          importElement.uriEnd = uriLiteral.end;
+          offset = uriLiteral.offset;
+          length = uriLiteral.length;
         }
-        importElement.uri = node.uriContent;
-        importElement.deferred = node.deferredKeyword != null;
-        importElement.combinators = _buildCombinators(node);
-        importElement.importedLibrary = importedLibrary;
-        setElementDocumentationComment(importElement, node);
-        SimpleIdentifier prefixNode = node.prefix;
-        if (prefixNode != null) {
-          importElement.prefixOffset = prefixNode.offset;
-          String prefixName = prefixNode.name;
-          PrefixElementImpl prefix = nameToPrefixMap[prefixName];
-          if (prefix == null) {
-            prefix = new PrefixElementImpl.forNode(prefixNode);
-            nameToPrefixMap[prefixName] = prefix;
-          }
-          importElement.prefix = prefix;
-          prefixNode.staticElement = prefix;
-        }
-        node.element = importElement;
-        imports.add(importElement);
-        if (importSourceKindMap[importedSource] != SourceKind.LIBRARY) {
-          int offset = node.offset;
-          int length = node.length;
-          if (uriLiteral != null) {
-            offset = uriLiteral.offset;
-            length = uriLiteral.length;
-          }
-          ErrorCode errorCode = (importElement.isDeferred
-              ? StaticWarningCode.IMPORT_OF_NON_LIBRARY
-              : CompileTimeErrorCode.IMPORT_OF_NON_LIBRARY);
-          errors.add(new AnalysisError(libraryElement.source, offset, length,
-              errorCode, [uriLiteral.toSource()]));
-        }
+        ErrorCode errorCode = importElement.isDeferred
+            ? StaticWarningCode.IMPORT_OF_NON_LIBRARY
+            : CompileTimeErrorCode.IMPORT_OF_NON_LIBRARY;
+        errors.add(new AnalysisError(libraryElement.source, offset, length,
+            errorCode, [uriLiteral.toSource()]));
       }
     }
     return null;
   }
 
   @override
   Object visitLibraryDirective(LibraryDirective node) {
     (node.element as LibraryElementImpl)?.metadata =
         _getElementAnnotations(node.metadata);
     return null;
@@ skipping 695 matching lines @@
           element.generator = true;
         }
         if (node.returnType == null) {
           element.hasImplicitReturnType = true;
         }
         _currentHolder.addMethod(element);
         methodName.staticElement = element;
       } else {
         SimpleIdentifier propertyNameNode = node.name;
         String propertyName = propertyNameNode.name;
-        FieldElementImpl field =
-            _currentHolder.getField(propertyName, synthetic: true) as FieldElementImpl;
+        FieldElementImpl field = _currentHolder.getField(propertyName,
+            synthetic: true) as FieldElementImpl;
         if (field == null) {
           field = new FieldElementImpl(node.name.name, -1);
           field.final2 = true;
           field.static = isStatic;
           field.synthetic = true;
           _currentHolder.addField(field);
         }
         if (node.isGetter) {
           PropertyAccessorElementImpl getter =
               new PropertyAccessorElementImpl.forNode(propertyNameNode);
@@ skipping 467 matching lines @@
     return null;
   }
 
   /**
    * Return the lexical identifiers associated with the given [identifiers].
    */
   static List<String> _getIdentifiers(NodeList<SimpleIdentifier> identifiers) {
     return identifiers.map((identifier) => identifier.name).toList();
   }
 }