Issue 29288. Resynthesize Import/Export/PartElement for every directive.

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

Index: pkg/analyzer/lib/src/dart/analysis/library_analyzer.dart
diff --git a/pkg/analyzer/lib/src/dart/analysis/library_analyzer.dart b/pkg/analyzer/lib/src/dart/analysis/library_analyzer.dart
index aa9d56ba7426d3f152e0ed86c878f507289804cd..9222dd196ccd931538df70d2908e5539bbe9edf5 100644
--- a/pkg/analyzer/lib/src/dart/analysis/library_analyzer.dart
+++ b/pkg/analyzer/lib/src/dart/analysis/library_analyzer.dart
@@ -158,6 +158,10 @@ class LibraryAnalyzer {
   }
 
   void _computeHints(FileState file, CompilationUnit unit) {
+    if (file.source == null) {
+      return;
+    }
+
     AnalysisErrorListener errorListener = _getErrorListener(file);
     ErrorReporter errorReporter = _getErrorReporter(file);
 
@@ -209,6 +213,10 @@ class LibraryAnalyzer {
   }
 
   void _computeLints(FileState file, CompilationUnit unit) {
+    if (file.source == null) {
+      return;
+    }
+
     ErrorReporter errorReporter = _getErrorReporter(file);
 
     List<AstVisitor> visitors = <AstVisitor>[];
@@ -239,6 +247,10 @@ class LibraryAnalyzer {
   }
 
   void _computeVerifyErrors(FileState file, CompilationUnit unit) {
+    if (file.source == null) {
+      return;
+    }
+
     RecordingErrorListener errorListener = _getErrorListener(file);
 
     if (_analysisOptions.strongMode) {
@@ -377,24 +389,14 @@ class LibraryAnalyzer {
 
   void _resolveDirectives(Map<FileState, CompilationUnit> units) {
     CompilationUnit definingCompilationUnit = units[_library];
-
-    var uriToElement = <Uri, CompilationUnitElement>{};
-    for (CompilationUnitElement partElement in _libraryElement.units) {
-      uriToElement[partElement.source.uri] = partElement;
-    }
-
-    var sourceToUnit = <Source, CompilationUnit>{};
-    units.forEach((file, unit) {
-      Source source = file.source;
-      unit.element = uriToElement[source.uri];
-      sourceToUnit[source] = unit;
-    });
+    definingCompilationUnit.element = _libraryElement.definingCompilationUnit;
 
     ErrorReporter libraryErrorReporter = _getErrorReporter(_library);
     LibraryIdentifier libraryNameNode = null;
     bool hasPartDirective = false;
     var seenPartSources = new Set<Source>();
     var directivesToResolve = <Directive>[];
+    int partIndex = 0;
     for (Directive directive in definingCompilationUnit.directives) {
       if (directive is LibraryDirective) {
         libraryNameNode = directive.name;
@@ -403,7 +405,8 @@ class LibraryAnalyzer {
         for (ImportElement importElement in _libraryElement.imports) {
           if (importElement.nameOffset == directive.offset) {
             directive.element = importElement;
-            if (!_isLibrarySource(importElement.importedLibrary.source)) {
+            Source source = importElement.importedLibrary?.source;
+            if (source != null && !_isLibrarySource(source)) {
               ErrorCode errorCode = importElement.isDeferred
                   ? StaticWarningCode.IMPORT_OF_NON_LIBRARY
                   : CompileTimeErrorCode.IMPORT_OF_NON_LIBRARY;
@@ -416,7 +419,8 @@ class LibraryAnalyzer {
         for (ExportElement exportElement in _libraryElement.exports) {
           if (exportElement.nameOffset == directive.offset) {
             directive.element = exportElement;
-            if (!_isLibrarySource(exportElement.exportedLibrary.source)) {
+            Source source = exportElement.exportedLibrary?.source;
+            if (source != null && !_isLibrarySource(source)) {
               libraryErrorReporter.reportErrorForNode(
                   CompileTimeErrorCode.EXPORT_OF_NON_LIBRARY,
                   directive.uri,
@@ -427,46 +431,55 @@ class LibraryAnalyzer {
       } else if (directive is PartDirective) {
         hasPartDirective = true;
         StringLiteral partUri = directive.uri;
+
+        FileState partFile = _library.partedFiles[partIndex];
+        CompilationUnit partUnit = units[partFile];
+        CompilationUnitElement partElement = _libraryElement.parts[partIndex];
+        partUnit.element = partElement;
+        directive.element = partElement;
+        partIndex++;
+
         Source partSource = directive.uriSource;
-        CompilationUnit partUnit = sourceToUnit[partSource];
-        if (partUnit != null) {
-          directive.element = partUnit.element;
-          //
-          // Validate that the part source is unique in the library.
-          //
-          if (!seenPartSources.add(partSource)) {
+        if (partSource == null) {
+          continue;
+        }
+
+        //
+        // Validate that the part source is unique in the library.
+        //
+        if (!seenPartSources.add(partSource)) {
+          libraryErrorReporter.reportErrorForNode(
+              CompileTimeErrorCode.DUPLICATE_PART, partUri, [partSource.uri]);
+        }
+
+        //
+        // Validate that the part contains a part-of directive with the same
+        // name as the library.

[Brian Wilkerson, 2017/04/09 16:01:24]

"name" --> "name or uri"

+        //
+        if (_context.exists(partSource)) {
+          _NameOrSource nameOrSource = _getPartLibraryNameOrUri(
+              partSource, partUnit, directivesToResolve);
+          if (nameOrSource == null) {
             libraryErrorReporter.reportErrorForNode(
-                CompileTimeErrorCode.DUPLICATE_PART, partUri, [partSource.uri]);
-          }
-          //
-          // Validate that the part contains a part-of directive with the same
-          // name as the library.
-          //
-          if (_context.exists(partSource)) {
-            _NameOrSource nameOrSource = _getPartLibraryNameOrUri(
-                partSource, partUnit, directivesToResolve);
-            if (nameOrSource == null) {
-              libraryErrorReporter.reportErrorForNode(
-                  CompileTimeErrorCode.PART_OF_NON_PART,
-                  partUri,
-                  [partUri.toSource()]);
+                CompileTimeErrorCode.PART_OF_NON_PART,
+                partUri,
+                [partUri.toSource()]);
+          } else {
+            String name = nameOrSource.name;
+            if (name != null) {
+              if (libraryNameNode != null && libraryNameNode.name != name) {
+                libraryErrorReporter.reportErrorForNode(
+                    StaticWarningCode.PART_OF_DIFFERENT_LIBRARY,
+                    partUri,
+                    [libraryNameNode.name, name]);
+              }
             } else {
-              String name = nameOrSource.name;
-              if (name != null) {
-                if (libraryNameNode != null && libraryNameNode.name != name) {
-                  libraryErrorReporter.reportErrorForNode(
-                      StaticWarningCode.PART_OF_DIFFERENT_LIBRARY,
-                      partUri,
-                      [libraryNameNode.name, name]);
-                }
-              } else {
-                Source source = nameOrSource.source;
-                if (source != _library.source) {
-                  libraryErrorReporter.reportErrorForNode(
-                      StaticWarningCode.PART_OF_DIFFERENT_LIBRARY,
-                      partUri,
-                      [_library.uriStr, source.uri]);
-                }
+              Source source = nameOrSource.source;
+              if (source != _library.source) {
+                libraryErrorReporter.reportErrorForNode(
+                    StaticWarningCode.PART_OF_DIFFERENT_LIBRARY,
+                    partUri,
+                    [_library.uriStr, source.uri]);
               }
             }
           }
@@ -492,10 +505,14 @@ class LibraryAnalyzer {
   }
 
   void _resolveFile(FileState file, CompilationUnit unit) {
+    Source source = file.source;
+    if (source == null) {
+      return;
+    }
+
     RecordingErrorListener errorListener = _getErrorListener(file);
 
     CompilationUnitElement unitElement = unit.element;
-    Source source = file.source;
 
     // TODO(scheglov) Hack: set types for top-level variables
     // Otherwise TypeResolverVisitor will set declared types, and because we