Include referenced declared variables and their values into the linked bundle hash.

pkg/analyzer/lib/src/summary/pub_summary.dart

Index: pkg/analyzer/lib/src/summary/pub_summary.dart
diff --git a/pkg/analyzer/lib/src/summary/pub_summary.dart b/pkg/analyzer/lib/src/summary/pub_summary.dart
index 589118361ebeaf0a3c81b3eae9d4183ad6ace9e4..2f1d2a79d87cfe13076fc83643af9ced0a7640b3 100644
--- a/pkg/analyzer/lib/src/summary/pub_summary.dart
+++ b/pkg/analyzer/lib/src/summary/pub_summary.dart
@@ -33,6 +33,12 @@ import 'package:meta/meta.dart';
 import 'package:path/path.dart' as pathos;
 
 /**
+ * Return the raw string value of the variable with the given [name],
+ * or `null` of the variable is not defined.
+ */
+typedef String _GetDeclaredVariable(String name);
+
+/**
  * Unlinked and linked information about a [PubPackage].
  */
 class LinkedPubPackage {
@@ -84,6 +90,12 @@ class PubSummaryManager {
   static const UNLINKED_SPEC_NAME = 'unlinked_spec.ds';
 
   /**
+   * If `true` (by default), then linking new bundles is allowed.
+   * Otherwise only using existing cached bundles can be used.
+   */
+  final bool allowLinking;
+
+  /**
    * See [PackageBundleAssembler.currentMajorVersion].
    */
   final int majorVersion;
@@ -126,7 +138,8 @@ class PubSummaryManager {
   Completer _onUnlinkedCompleteCompleter;
 
   PubSummaryManager(this.resourceProvider, this.tempFileName,
-      {@visibleForTesting this.majorVersion:
+      {@visibleForTesting this.allowLinking: true,
+      @visibleForTesting this.majorVersion:
           PackageBundleAssembler.currentMajorVersion});
 
   /**
@@ -196,7 +209,12 @@ class PubSummaryManager {
     Map<String, _LinkedNode> packageToNode = <String, _LinkedNode>{};
     unlinkedBundles.forEach((package, unlinked) {
       _LinkedNode node = new _LinkedNode(
-          sdkBundle, listedPackages, package, unlinked, packageToNode);
+          sdkBundle,
+          context.declaredVariables.get,
+          listedPackages,
+          package,
+          unlinked,
+          packageToNode);
       nodes.add(node);
       packageToNode[package.name] = node;
     });
@@ -211,28 +229,31 @@ class PubSummaryManager {
       _readLinked(node, strong);
     }
 
-    // Fill the store with bundles.
-    // Append the linked SDK bundle.
-    // Append unlinked and (if read from a cache) linked package bundles.
-    SummaryDataStore store = new SummaryDataStore(const <String>[]);
-    store.addBundle(null, sdkBundle);
-    for (_LinkedNode node in nodes) {
-      store.addBundle(null, node.unlinked);
-      if (node.linked != null) {
-        store.addBundle(null, node.linked);
+    // Link new bundles, if allowed.
+    if (allowLinking) {
+      // Fill the store with bundles.
+      // Append the linked SDK bundle.
+      // Append unlinked and (if read from a cache) linked package bundles.
+      SummaryDataStore store = new SummaryDataStore(const <String>[]);
+      store.addBundle(null, sdkBundle);
+      for (_LinkedNode node in nodes) {
+        store.addBundle(null, node.unlinked);
+        if (node.linked != null) {
+          store.addBundle(null, node.linked);
+        }
       }
-    }
 
-    // Link each package node.
-    for (_LinkedNode node in nodes) {
-      if (!node.isEvaluated) {
-        new _LinkedWalker(listedPackages, store, strong).walk(node);
+      // Link each package node.
+      for (_LinkedNode node in nodes) {
+        if (!node.isEvaluated) {
+          new _LinkedWalker(listedPackages, store, strong).walk(node);
+        }
       }
-    }
 
-    // Write newly linked bundles.
-    for (_LinkedNode node in nodes) {
-      _writeLinked(node, strong);
+      // Write newly linked bundles.
+      for (_LinkedNode node in nodes) {
+        _writeLinked(node, strong);
+      }
     }
 
     // Create successfully linked packages.
@@ -240,7 +261,7 @@ class PubSummaryManager {
     for (_LinkedNode node in nodes) {
       if (node.linked != null) {
         linkedPackages.add(new LinkedPubPackage(
-            node.package, node.unlinked, node.linked, node._linkedHash));
+            node.package, node.unlinked, node.linked, node.linkedHash));
       }
     }
 
@@ -604,6 +625,7 @@ class PubSummaryManager {
  */
 class _LinkedNode extends Node<_LinkedNode> {
   final PackageBundle sdkBundle;
+  final _GetDeclaredVariable getDeclaredVariable;
   final _ListedPackages listedPackages;
   final PubPackage package;
   final PackageBundle unlinked;
@@ -616,30 +638,31 @@ class _LinkedNode extends Node<_LinkedNode> {
   List<int> linkedNewBytes;
   PackageBundle linked;
 
-  _LinkedNode(this.sdkBundle, this.listedPackages, this.package, this.unlinked,
-      this.packageToNode);
+  _LinkedNode(this.sdkBundle, this.getDeclaredVariable, this.listedPackages,
+      this.package, this.unlinked, this.packageToNode);
 
   @override
   bool get isEvaluated => linked != null || failed;
 
   /**
    * Return the hash string that corresponds to this linked bundle in the
-   * context of its [sdkBundles] and transitive dependencies.  Return `null` if
+   * context of its [sdkBundle] and transitive dependencies.  Return `null` if
    * the hash computation fails, because for example the full transitive
    * dependencies cannot computed.
    */
   String get linkedHash {
     if (_linkedHash == null && transitiveDependencies != null) {
-      // Collect all unlinked API signatures.
+      ApiSignature signature = new ApiSignature();
+      // Add all unlinked API signatures.
       List<String> signatures = <String>[];
       signatures.add(sdkBundle.apiSignature);
       transitiveDependencies
           .map((node) => node.unlinked.apiSignature)
           .forEach(signatures.add);
       signatures.sort();
-      // Combine sorted unlinked API signatures into a single hash.
-      ApiSignature signature = new ApiSignature();
       signatures.forEach(signature.addString);
+      // Combine into a single hash.
+      _appendDeclaredVariables(signature);
       _linkedHash = signature.toHex();
     }
     return _linkedHash;
@@ -709,6 +732,32 @@ class _LinkedNode extends Node<_LinkedNode> {
 
   @override
   String toString() => package.toString();
+
+  /**
+   * Append names and values of all referenced declared variables (even the
+   * ones without actually declared values) to the given [signature].
+   */
+  void _appendDeclaredVariables(ApiSignature signature) {
+    Set<String> names = new Set<String>();
+    for (_LinkedNode node in transitiveDependencies) {
+      for (UnlinkedUnit unit in node.unlinked.unlinkedUnits) {
+        for (UnlinkedImport import in unit.imports) {
+          for (UnlinkedConfiguration configuration in import.configurations) {
+            names.add(configuration.name);
+          }
+        }
+        for (UnlinkedExportPublic export in unit.publicNamespace.exports) {
+          for (UnlinkedConfiguration configuration in export.configurations) {
+            names.add(configuration.name);
+          }
+        }
+      }
+    }
+    for (String name in names) {

[Paul Berry, 2016/09/21 19:47:22]

Before the for loop, add:

signature.addInt(names.length);

(Otherwise there's a small risk of hash collisions).

Also, can we sort the names before adding them to the signature?  That would
reduce the risk of an unnecessary mismatch if the set iteration order changes.

[scheglov, 2016/09/21 20:34:49]

Done.

+      signature.addString(name);
+      signature.addString(getDeclaredVariable(name) ?? '');
+    }
+  }
 }
 
 /**