Add the ability to summarize inferred types based on function-typed parameters.

pkg/analyzer/tool/summary/idl.dart

 // Copyright (c) 2015, 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.
 
 /**
  * This file is an "idl" style description of the summary format.  It is not
  * executed directly; instead it is parsed and transformed into code that
  * implements the summary format.
  *
  * The code generation process introduces the following non-typical semantics:
@@ skipping 90 matching lines @@
    *
    * Then [paramReference] values of 1, 2, 3, and 4 represent W, V, U, and T,
    * respectively.
    *
    * If the type being referred to is not a type parameter, [paramReference] is
    * zero.
    */
   int paramReference;
 
   /**
+   * If this is a reference to a function type implicitly defined by a
+   * function-typed parameter, a list of zero-based indices indicating the path
+   * from the entity referred to by [reference] to the appropriate type
+   * parameter.  Otherwise the empty list.
+   *
+   * If there are N indices in this list, then the entity being referred to is
+   * the function type implicitly defined by a function-typed parameter of a
+   * function-typed parameter, to N levels of nesting.  The first index in the
+   * list refers to the outermost level of nesting; for example if [reference]
+   * refers to the entity defined by:
+   *
+   *     void f(x, void g(y, z, int h(String w))) { ... }
+   *
+   * Then to refer to the function type implicitly defined by parameter `h`
+   * (which is parameter 2 of parameter 1 of `f`), then
+   * [implicitFunctionTypeIndices] should be [1, 2].
+   *
+   * Note that if the entity being referred to is a generic method inside a
+   * generic class, then the type arguments in [typeArguments] are applied
+   * first to the class and then to the method.
+   */
+  List<int> implicitFunctionTypeIndices;
+
+  /**
    * If this is an instantiation of a generic type or generic executable, the
    * type arguments used to instantiate it.  Trailing type arguments of type
    * `dynamic` are omitted.
    */
   List<EntityRef> typeArguments;
 }
 
 /**
  * Information about a dependency that exists between one library and another
  * due to an "import" declaration.
@@ skipping 100 matching lines @@
   int numPrelinkedDependencies;
 }
 
 /**
  * Information about the resolution of an [UnlinkedReference].
  */
 class LinkedReference {
   /**
    * Index into [LinkedLibrary.dependencies] indicating which imported library
    * declares the entity being referred to.
+   *
+   * Zero if this entity is contained within another entity (e.g. a class
+   * member).
    */
   int dependency;
 
   /**
    * The kind of the entity being referred to.  For the pseudo-types `dynamic`
    * and `void`, the kind is [ReferenceKind.classOrEnum].
    */
   ReferenceKind kind;
 
   /**
    * Integer index indicating which unit in the imported library contains the
    * definition of the entity.  As with indices into [LinkedLibrary.units],
    * zero represents the defining compilation unit, and nonzero values
    * represent parts in the order of the corresponding `part` declarations.
+   *
+   * Zero if this entity is contained within another entity (e.g. a class
+   * member).
    */
   int unit;
 
   /**
    * If the entity being referred to is generic, the number of type parameters
    * it accepts.  Otherwise zero.
    */
   int numTypeParameters;
 
   /**
    * If this [LinkedReference] doesn't have an associated [UnlinkedReference],
    * name of the entity being referred to.  For the pseudo-type `dynamic`, the
    * string is "dynamic".  For the pseudo-type `void`, the string is "void".
    */
   String name;
+
+  /**
+   * If this [LinkedReference] doesn't have an associated [UnlinkedReference],
+   * and the entity being referred to is contained within another entity, index
+   * of the containing entity.  This behaves similarly to
+   * [UnlinkedReference.prefixReference], however it is only used for class
+   * members, not for prefixed imports.
+   *
+   * Containing references must always point backward; that is, for all i, if
+   * LinkedUnit.references[i].containingReference != 0, then
+   * LinkedUnit.references[i].containingReference < i.
+   */
+  int containingReference;
 }
 
 /**
  * Linked summary of a compilation unit.
  */
 class LinkedUnit {
   /**
    * Information about the resolution of references within the compilation
    * unit.  Each element of [UnlinkedUnit.references] has a corresponding
    * element in this list (at the same index).  If this list has additional
@@ skipping 1189 matching lines @@
   int propagatedTypeSlot;
 
   /**
    * If this variable is inferrable, nonzero slot id identifying which entry in
    * [LinkedLibrary.types] contains the inferred type for this variable.  If
    * there is no matching entry in [LinkedLibrary.types], then no type was
    * inferred for this variable, so its static type is `dynamic`.
    */
   int inferredTypeSlot;
 }