Redo "Information about which functions require other functions is gathered in the enqueuer."

sdk/lib/_internal/compiler/implementation/compilation_info.dart

Index: sdk/lib/_internal/compiler/implementation/compilation_info.dart
diff --git a/sdk/lib/_internal/compiler/implementation/compilation_info.dart b/sdk/lib/_internal/compiler/implementation/compilation_info.dart
new file mode 100644
index 0000000000000000000000000000000000000000..befa90f294cf71081c28b712960195944ccea95e
--- /dev/null
+++ b/sdk/lib/_internal/compiler/implementation/compilation_info.dart
@@ -0,0 +1,63 @@
+library dart2js.compilation_info;
+
+import 'dart2jslib.dart';
+import 'elements/elements.dart';
+import 'tree/tree.dart';
+
+
+class CompilationInformation {
+  static const DUMP_COMPILATION_INFO_DATABASE = true;
+
+  CompilationInformation._internal();
+
+  factory CompilationInformation(Enqueuer enqueuer) {
+    if (DUMP_COMPILATION_INFO_DATABASE) {
+      return new _CompilationInformation(enqueuer);
+    } else {
+      return new CompilationInformation._internal();
+    }
+  }
+
+
+  Map<String, Map<dynamic, Set>> relations = {};
+
+  void enqueues(Element function, Element source) {}
+  void addsToWorkList(Element context, Element element) {}
+  void registerCallSite(TreeElements context, Send node) {}
+}
+
+
+class _CompilationInformation implements CompilationInformation {
+  final String prefix;
+
+  Map<String, Map<dynamic, Set>> relations = {};
+
+  _CompilationInformation(Enqueuer enqueuer)
+    : prefix = enqueuer.isResolutionQueue ? 'resolution' : 'codegen';
+
+  Set<CallSite> callSites = new Set<CallSite>();
+
+  put(String relation, target, source) {
+    relations.putIfAbsent(relation, () => {})
+      .putIfAbsent(target, () => new Set())
+      .add(source);
+  }
+
+  enqueues(Element function, Element source) {
+    put('enqueues', function, source);
+  }
+
+  addsToWorkList(Element context, Element element) {
+    put('addsToWorklist', context, element);
+  }
+
+  registerCallSite(TreeElements context, Send node) {
+    callSites.add(new CallSite(context, node));
+  }
+}
+
+class CallSite {
+  final TreeElements context;
+  final Send node;
+  CallSite(this.context, this.node);
+}