Issue 27044. Summarize configurations of imports and exports, AST based.

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

Index: pkg/analyzer/lib/src/summary/idl.dart
diff --git a/pkg/analyzer/lib/src/summary/idl.dart b/pkg/analyzer/lib/src/summary/idl.dart
index 3cd65626fcc405d53ee3580ef1fbb6a269ac0726..74d63f1801a8d3b324c7bfe2087af11eac4fad2a 100644
--- a/pkg/analyzer/lib/src/summary/idl.dart
+++ b/pkg/analyzer/lib/src/summary/idl.dart
@@ -1130,6 +1130,31 @@ abstract class UnlinkedCombinator extends base.SummaryClass {
 }
 
 /**
+ * Unlinked summary information about a single import or export configuration.
+ */
+abstract class UnlinkedConfiguration extends base.SummaryClass {
+  /**
+   * The name of the declared variable whose value is being used in the
+   * condition.
+   */
+  @Id(0)
+  String get name;
+
+  /**
+   * The URI of the implementation library to be used if the condition is true.
+   */
+  @Id(2)
+  String get uri;
+
+  /**
+   * The value to which the value of the declared variable will be compared,
+   * an empty string if the condition does not include an equality test.

[Paul Berry, 2016/09/15 17:02:38]

It seems like this will make it impossible to distinguish between conditions

if (foo == '') 'bar.dart'

and

if (foo) 'bar.dart'

Is that a problem?

[scheglov, 2016/09/15 17:42:46]

Yes, it is.
We should implicitly use 'true', not the empty string.
Fixed.

+   */
+  @Id(1)
+  String get value;
+}
+
+/**
  * Unlinked summary information about a compile-time constant expression, or a
  * potentially constant expression.
  *
@@ -2063,12 +2088,19 @@ abstract class UnlinkedExportNonPublic extends base.SummaryClass {
  */
 abstract class UnlinkedExportPublic extends base.SummaryClass {
   /**
-   * Combinators contained in this import declaration.
+   * Combinators contained in this export declaration.
    */
   @Id(1)
   List<UnlinkedCombinator> get combinators;
 
   /**
+   * Configurations used to control which library will actually be loaded at
+   * run-time.
+   */
+  @Id(2)
+  List<UnlinkedConfiguration> get configurations;
+
+  /**
    * URI used in the source code to reference the exported library.
    */
   @Id(0)
@@ -2186,6 +2218,13 @@ abstract class UnlinkedImport extends base.SummaryClass {
   List<UnlinkedCombinator> get combinators;
 
   /**
+   * Configurations used to control which library will actually be loaded at
+   * run-time.
+   */
+  @Id(10)
+  List<UnlinkedConfiguration> get configurations;
+
+  /**
    * Indicates whether the import declaration uses the `deferred` keyword.
    */
   @Id(9)