Use summary IDL file for interface classes.

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:
- * - Fields of type List are never null, and have a default value of the empty
- *   list.
- * - Fields of type int are unsigned 32-bit integers, never null, and have a
- *   default value of zero.
- * - Fields of type String are never null, and have a default value of ''.
- * - Fields of type bool are never null, and have a default value of false.
- * - Fields whose type is an enum are never null, and have a default value of
- *   the first value declared in the enum.
- *
- * Terminology used in this document:
- * - "Unlinked" refers to information that can be determined from reading a
- *   single .dart file in isolation.
- * - "Prelinked" refers to information that can be determined from the defining
- *   compilation unit of a library, plus direct imports, plus the transitive
- *   closure of exports reachable from those libraries, plus all part files
- *   constituting those libraries.
- * - "Linked" refers to all other information; in theory, this information may
- *   depend on all files in the transitive import/export closure.  However, in
- *   practice we expect that the number of additional dependencies will usually
- *   be small, since the additional dependencies only need to be consulted for
- *   type propagation, type inference, and constant evaluation, which typically
- *   have short dependency chains.
- *
- * Since we expect "linked" and "prelinked" dependencies to be similar, we only
- * rarely distinguish between them; most information is that is not "unlinked"
- * is typically considered "linked" for simplicity.
- *
- * Except as otherwise noted, synthetic elements are not stored in the summary;
- * they are re-synthesized at the time the summary is read.
- */
-library analyzer.tool.summary.idl;
-
-/**
- * Annotation describing information which is not part of Dart semantics; in
- * other words, if this information (or any information it refers to) changes,
- * static analysis and runtime behavior of the library are unaffected.
- *
- * TODO(paulberry): some informative information is currently missing from the
- * summary format.
- */
-const informative = null;
-
-/**
- * Annotation describing information which is not part of the public API to a
- * library; in other words, if this information (or any information it refers
- * to) changes, libraries outside this one are unaffected.
- *
- * TODO(paulberry): currently the summary format does not contain private
- * information.
- */
-const private = null;
-
-/**
- * Annotation describing a class which can be the top level object in an
- * encoded summary.
- */
-const topLevel = null;
-
-/**
- * Summary information about a reference to a an entity such as a type, top
- * level executable, or executable within a class.
- */
-class EntityRef {
-  /**
-   * If this [EntityRef] is contained within [LinkedUnit.types], slot id (which
-   * is unique within the compilation unit) identifying the target of type
-   * propagation or type inference with which this [EntityRef] is associated.
-   *
-   * Otherwise zero.
-   */
-  int slot;
-
-  /**
-   * Index into [UnlinkedUnit.references] for the entity being referred to, or
-   * zero if this is a reference to a type parameter.
-   */
-  int reference;
-
-  /**
-   * If this is a reference to a type parameter, one-based index into the list
-   * of [UnlinkedTypeParam]s currently in effect.  Indexing is done using De
-   * Bruijn index conventions; that is, innermost parameters come first, and
-   * if a class or method has multiple parameters, they are indexed from right
-   * to left.  So for instance, if the enclosing declaration is
-   *
-   *     class C<T,U> {
-   *       m<V,W> {
-   *         ...
-   *       }
-   *     }
-   *
-   * 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.
- */
-class LinkedDependency {
-  /**
-   * The relative URI of the dependent library.  This URI is relative to the
-   * importing library, even if there are intervening `export` declarations.
-   * So, for example, if `a.dart` imports `b/c.dart` and `b/c.dart` exports
-   * `d/e.dart`, the URI listed for `a.dart`'s dependency on `e.dart` will be
-   * `b/d/e.dart`.
-   */
-  String uri;
-
-  /**
-   * URI for the compilation units listed in the library's `part` declarations.
-   * These URIs are relative to the importing library.
-   */
-  List<String> parts;
-}
-
-/**
- * Information about a single name in the export namespace of the library that
- * is not in the public namespace.
- */
-class LinkedExportName {
-  /**
-   * Name of the exported entity.  For an exported setter, this name includes
-   * the trailing '='.
-   */
-  String name;
-
-  /**
-   * Index into [LinkedLibrary.dependencies] for the library in which the
-   * entity is defined.
-   */
-  int dependency;
-
-  /**
-   * Integer index indicating which unit in the exported 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.
-   */
-  int unit;
-
-  /**
-   * The kind of the entity being referred to.
-   */
-  ReferenceKind kind;
-}
-
-/**
- * Linked summary of a library.
- */
-@topLevel
-class LinkedLibrary {
-  /**
-   * The linked summary of all the compilation units constituting the
-   * library.  The summary of the defining compilation unit is listed first,
-   * followed by the summary of each part, in the order of the `part`
-   * declarations in the defining compilation unit.
-   */
-  List<LinkedUnit> units;
-
-  /**
-   * The libraries that this library depends on (either via an explicit import
-   * statement or via the implicit dependencies on `dart:core` and
-   * `dart:async`).  The first element of this array is a pseudo-dependency
-   * representing the library itself (it is also used for `dynamic` and
-   * `void`).  This is followed by elements representing "prelinked"
-   * dependencies (direct imports and the transitive closure of exports).
-   * After the prelinked dependencies are elements representing "linked"
-   * dependencies.
-   *
-   * A library is only included as a "linked" dependency if it is a true
-   * dependency (e.g. a propagated or inferred type or constant value
-   * implicitly refers to an element declared in the library) or
-   * anti-dependency (e.g. the result of type propagation or type inference
-   * depends on the lack of a certain declaration in the library).
-   */
-  List<LinkedDependency> dependencies;
-
-  /**
-   * For each import in [UnlinkedUnit.imports], an index into [dependencies]
-   * of the library being imported.
-   */
-  List<int> importDependencies;
-
-  /**
-   * Information about entities in the export namespace of the library that are
-   * not in the public namespace of the library (that is, entities that are
-   * brought into the namespace via `export` directives).
-   *
-   * Sorted by name.
-   */
-  List<LinkedExportName> exportNames;
-
-  /**
-   * The number of elements in [dependencies] which are not "linked"
-   * dependencies (that is, the number of libraries in the direct imports plus
-   * the transitive closure of exports, plus the library itself).
-   */
-  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
-   * elements beyond the number of elements in [UnlinkedUnit.references], those
-   * additional elements are references that are only referred to implicitly
-   * (e.g. elements involved in inferred or propagated types).
-   */
-  List<LinkedReference> references;
-
-  /**
-   * List associating slot ids found inside the unlinked summary for the
-   * compilation unit with propagated and inferred types.
-   */
-  List<EntityRef> types;
-}
-
-/**
- * Enum used to indicate the kind of entity referred to by a
- * [LinkedReference].
- */
-enum ReferenceKind {
-  /**
-   * The entity is a class or enum.
-   */
-  classOrEnum,
-
-  /**
-   * The entity is a constructor.
-   */
-  constructor,
-
-  /**
-   * The entity is a getter or setter inside a class.  Note: this is used in
-   * the case where a constant refers to a static const declared inside a
-   * class.
-   */
-  propertyAccessor,
-
-  /**
-   * The entity is a method.
-   */
-  method,
-
-  /**
-   * The `length` property access.
-   */
-  length,
-
-  /**
-   * The entity is a typedef.
-   */
-  typedef,
-
-  /**
-   * The entity is a top level function.
-   */
-  topLevelFunction,
-
-  /**
-   * The entity is a top level getter or setter.
-   */
-  topLevelPropertyAccessor,
-
-  /**
-   * The entity is a prefix.
-   */
-  prefix,
-
-  /**
-   * The entity being referred to does not exist.
-   */
-  unresolved
-}
-
-/**
- * Information about SDK.
- */
-@topLevel
-class SdkBundle {
-  /**
-   * The list of URIs of items in [linkedLibraries], e.g. `dart:core`.
-   */
-  List<String> linkedLibraryUris;
-
-  /**
-   * Linked libraries.
-   */
-  List<LinkedLibrary> linkedLibraries;
-
-  /**
-   * The list of URIs of items in [unlinkedUnits], e.g. `dart:core/bool.dart`.
-   */
-  List<String> unlinkedUnitUris;
-
-  /**
-   * Unlinked information for the compilation units constituting the SDK.
-   */
-  List<UnlinkedUnit> unlinkedUnits;
-}
-
-/**
- * Unlinked summary information about a class declaration.
- */
-class UnlinkedClass {
-  /**
-   * Name of the class.
-   */
-  String name;
-
-  /**
-   * Offset of the class name relative to the beginning of the file.
-   */
-  @informative
-  int nameOffset;
-
-  /**
-   * Documentation comment for the class, or `null` if there is no
-   * documentation comment.
-   */
-  @informative
-  UnlinkedDocumentationComment documentationComment;
-
-  /**
-   * Type parameters of the class, if any.
-   */
-  List<UnlinkedTypeParam> typeParameters;
-
-  /**
-   * Supertype of the class, or `null` if either (a) the class doesn't
-   * explicitly declare a supertype (and hence has supertype `Object`), or (b)
-   * the class *is* `Object` (and hence has no supertype).
-   */
-  EntityRef supertype;
-
-  /**
-   * Mixins appearing in a `with` clause, if any.
-   */
-  List<EntityRef> mixins;
-
-  /**
-   * Interfaces appearing in an `implements` clause, if any.
-   */
-  List<EntityRef> interfaces;
-
-  /**
-   * Field declarations contained in the class.
-   */
-  List<UnlinkedVariable> fields;
-
-  /**
-   * Executable objects (methods, getters, and setters) contained in the class.
-   */
-  List<UnlinkedExecutable> executables;
-
-  /**
-   * Indicates whether the class is declared with the `abstract` keyword.
-   */
-  bool isAbstract;
-
-  /**
-   * Indicates whether the class is declared using mixin application syntax.
-   */
-  bool isMixinApplication;
-
-  /**
-   * Indicates whether this class is the core "Object" class (and hence has no
-   * supertype)
-   */
-  bool hasNoSupertype;
-}
-
-/**
- * Unlinked summary information about a `show` or `hide` combinator in an
- * import or export declaration.
- */
-class UnlinkedCombinator {
-  /**
-   * List of names which are shown.  Empty if this is a `hide` combinator.
-   */
-  List<String> shows;
-
-  /**
-   * List of names which are hidden.  Empty if this is a `show` combinator.
-   */
-  List<String> hides;
-}
-
-/**
- * Unlinked summary information about a compile-time constant expression, or a
- * potentially constant expression.
- *
- * Constant expressions are represented using a simple stack-based language
- * where [operations] is a sequence of operations to execute starting with an
- * empty stack.  Once all operations have been executed, the stack should
- * contain a single value which is the value of the constant.  Note that some
- * operations consume additional data from the other fields of this class.
- */
-class UnlinkedConst {
-  /**
-   * Sequence of operations to execute (starting with an empty stack) to form
-   * the constant value.
-   */
-  List<UnlinkedConstOperation> operations;
-
-  /**
-   * Sequence of unsigned 32-bit integers consumed by the operations
-   * `pushArgument`, `pushInt`, `shiftOr`, `concatenate`, `invokeConstructor`,
-   * `makeList`, and `makeMap`.
-   */
-  List<int> ints;
-
-  /**
-   * Sequence of 64-bit doubles consumed by the operation `pushDouble`.
-   */
-  List<double> doubles;
-
-  /**
-   * Sequence of strings consumed by the operations `pushString` and
-   * `invokeConstructor`.
-   */
-  List<String> strings;
-
-  /**
-   * Sequence of language constructs consumed by the operations
-   * `pushReference`, `invokeConstructor`, `makeList`, and `makeMap`.  Note
-   * that in the case of `pushReference` (and sometimes `invokeConstructor` the
-   * actual entity being referred to may be something other than a type.
-   */
-  List<EntityRef> references;
-}
-
-/**
- * Enum representing the various kinds of operations which may be performed to
- * produce a constant value.  These options are assumed to execute in the
- * context of a stack which is initially empty.
- */
-enum UnlinkedConstOperation {
-  /**
-   * Push the next value from [UnlinkedConst.ints] (a 32-bit unsigned integer)
-   * onto the stack.
-   *
-   * Note that Dart supports integers larger than 32 bits; these are
-   * represented by composing 32-bit values using the [pushLongInt] operation.
-   */
-  pushInt,
-
-  /**
-   * Get the number of components from [UnlinkedConst.ints], then do this number
-   * of times the following operations: multiple the current value by 2^32, "or"
-   * it with the next value in [UnlinkedConst.ints]. The initial value is zero.
-   * Push the result into the stack.
-   */
-  pushLongInt,
-
-  /**
-   * Push the next value from [UnlinkedConst.doubles] (a double precision
-   * floating point value) onto the stack.
-   */
-  pushDouble,
-
-  /**
-   * Push the constant `true` onto the stack.
-   */
-  pushTrue,
-
-  /**
-   * Push the constant `false` onto the stack.
-   */
-  pushFalse,
-
-  /**
-   * Push the next value from [UnlinkedConst.strings] onto the stack.
-   */
-  pushString,
-
-  /**
-   * Pop the top n values from the stack (where n is obtained from
-   * [UnlinkedConst.ints]), convert them to strings (if they aren't already),
-   * concatenate them into a single string, and push it back onto the stack.
-   *
-   * This operation is used to represent constants whose value is a literal
-   * string containing string interpolations.
-   */
-  concatenate,
-
-  /**
-   * Get the next value from [UnlinkedConst.strings], convert it to a symbol,
-   * and push it onto the stack.
-   */
-  makeSymbol,
-
-  /**
-   * Push the constant `null` onto the stack.
-   */
-  pushNull,
-
-  /**
-   * Evaluate a (potentially qualified) identifier expression and push the
-   * resulting value onto the stack.  The identifier to be evaluated is
-   * obtained from [UnlinkedConst.references].
-   *
-   * This operation is used to represent the following kinds of constants
-   * (which are indistinguishable from an unresolved AST alone):
-   *
-   * - A qualified reference to a static constant variable (e.g. `C.v`, where
-   *   C is a class and `v` is a constant static variable in `C`).
-   * - An identifier expression referring to a constant variable.
-   * - A simple or qualified identifier denoting a class or type alias.
-   * - A simple or qualified identifier denoting a top-level function or a
-   *   static method.
-   */
-  pushReference,
-
-  /**
-   * Pop the top `n` values from the stack (where `n` is obtained from
-   * [UnlinkedConst.ints]) into a list (filled from the end) and take the next
-   * `n` values from [UnlinkedConst.strings] and use the lists of names and
-   * values to create named arguments.  Then pop the top `m` values from the
-   * stack (where `m` is obtained from [UnlinkedConst.ints]) into a list (filled
-   * from the end) and use them as positional arguments.  Use the lists of
-   * positional and names arguments to invoke a constant constructor obtained
-   * from [UnlinkedConst.references], and push the resulting value back onto the
-   * stack.
-   *
-   * Note that for an invocation of the form `const a.b(...)` (where no type
-   * arguments are specified), it is impossible to tell from the unresolved AST
-   * alone whether `a` is a class name and `b` is a constructor name, or `a` is
-   * a prefix name and `b` is a class name.  For consistency between AST based
-   * and elements based summaries, references to default constructors are always
-   * recorded as references to corresponding classes.
-   */
-  invokeConstructor,
-
-  /**
-   * Pop the top n values from the stack (where n is obtained from
-   * [UnlinkedConst.ints]), place them in a [List], and push the result back
-   * onto the stack.  The type parameter for the [List] is implicitly `dynamic`.
-   */
-  makeUntypedList,
-
-  /**
-   * Pop the top 2*n values from the stack (where n is obtained from
-   * [UnlinkedConst.ints]), interpret them as key/value pairs, place them in a
-   * [Map], and push the result back onto the stack.  The two type parameters
-   * for the [Map] are implicitly `dynamic`.
-   */
-  makeUntypedMap,
-
-  /**
-   * Pop the top n values from the stack (where n is obtained from
-   * [UnlinkedConst.ints]), place them in a [List], and push the result back
-   * onto the stack.  The type parameter for the [List] is obtained from
-   * [UnlinkedConst.references].
-   */
-  makeTypedList,
-
-  /**
-   * Pop the top 2*n values from the stack (where n is obtained from
-   * [UnlinkedConst.ints]), interpret them as key/value pairs, place them in a
-   * [Map], and push the result back onto the stack.  The two type parameters for
-   * the [Map] are obtained from [UnlinkedConst.references].
-   */
-  makeTypedMap,
-
-  /**
-   * Pop the top 2 values from the stack, pass them to the predefined Dart
-   * function `identical`, and push the result back onto the stack.
-   */
-  identical,
-
-  /**
-   * Pop the top 2 values from the stack, evaluate `v1 == v2`, and push the
-   * result back onto the stack.
-   */
-  equal,
-
-  /**
-   * Pop the top 2 values from the stack, evaluate `v1 != v2`, and push the
-   * result back onto the stack.
-   */
-  notEqual,
-
-  /**
-   * Pop the top value from the stack, compute its boolean negation, and push
-   * the result back onto the stack.
-   */
-  not,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 && v2`, and push the
-   * result back onto the stack.
-   */
-  and,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 || v2`, and push the
-   * result back onto the stack.
-   */
-  or,
-
-  /**
-   * Pop the top value from the stack, compute its integer complement, and push
-   * the result back onto the stack.
-   */
-  complement,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 ^ v2`, and push the
-   * result back onto the stack.
-   */
-  bitXor,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 & v2`, and push the
-   * result back onto the stack.
-   */
-  bitAnd,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 | v2`, and push the
-   * result back onto the stack.
-   */
-  bitOr,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 >> v2`, and push the
-   * result back onto the stack.
-   */
-  bitShiftRight,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 << v2`, and push the
-   * result back onto the stack.
-   */
-  bitShiftLeft,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 + v2`, and push the
-   * result back onto the stack.
-   */
-  add,
-
-  /**
-   * Pop the top value from the stack, compute its integer negation, and push
-   * the result back onto the stack.
-   */
-  negate,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 - v2`, and push the
-   * result back onto the stack.
-   */
-  subtract,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 * v2`, and push the
-   * result back onto the stack.
-   */
-  multiply,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 / v2`, and push the
-   * result back onto the stack.
-   */
-  divide,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 ~/ v2`, and push the
-   * result back onto the stack.
-   */
-  floorDivide,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 > v2`, and push the
-   * result back onto the stack.
-   */
-  greater,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 < v2`, and push the
-   * result back onto the stack.
-   */
-  less,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 >= v2`, and push the
-   * result back onto the stack.
-   */
-  greaterEqual,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 <= v2`, and push the
-   * result back onto the stack.
-   */
-  lessEqual,
-
-  /**
-   * Pop the top 2 values from the stack, compute `v1 % v2`, and push the
-   * result back onto the stack.
-   */
-  modulo,
-
-  /**
-   * Pop the top 3 values from the stack, compute `v1 ? v2 : v3`, and push the
-   * result back onto the stack.
-   */
-  conditional,
-
-  /**
-   * Pop the top value from the stack, evaluate `v.length`, and push the result
-   * back onto the stack.
-   */
-  length,
-}
-
-/**
- * Unlinked summary information about a documentation comment.
- */
-class UnlinkedDocumentationComment {
-  /**
-   * Text of the documentation comment, with '\r\n' replaced by '\n'.
-   *
-   * References appearing within the doc comment in square brackets are not
-   * specially encoded.
-   */
-  String text;
-
-  /**
-   * Offset of the beginning of the documentation comment relative to the
-   * beginning of the file.
-   */
-  int offset;
-
-  /**
-   * Length of the documentation comment (prior to replacing '\r\n' with '\n').
-   */
-  int length;
-}
-
-/**
- * Unlinked summary information about an enum declaration.
- */
-class UnlinkedEnum {
-  /**
-   * Name of the enum type.
-   */
-  String name;
-
-  /**
-   * Offset of the enum name relative to the beginning of the file.
-   */
-  @informative
-  int nameOffset;
-
-  /**
-   * Documentation comment for the enum, or `null` if there is no documentation
-   * comment.
-   */
-  @informative
-  UnlinkedDocumentationComment documentationComment;
-
-  /**
-   * Values listed in the enum declaration, in declaration order.
-   */
-  List<UnlinkedEnumValue> values;
-}
-
-/**
- * Unlinked summary information about a single enumerated value in an enum
- * declaration.
- */
-class UnlinkedEnumValue {
-  /**
-   * Name of the enumerated value.
-   */
-  String name;
-
-  /**
-   * Offset of the enum value name relative to the beginning of the file.
-   */
-  @informative
-  int nameOffset;
-
-  /**
-   * Documentation comment for the enum value, or `null` if there is no
-   * documentation comment.
-   */
-  @informative
-  UnlinkedDocumentationComment documentationComment;
-}
-
-/**
- * Unlinked summary information about a function, method, getter, or setter
- * declaration.
- */
-class UnlinkedExecutable {
-  /**
-   * Name of the executable.  For setters, this includes the trailing "=".  For
-   * named constructors, this excludes the class name and excludes the ".".
-   * For unnamed constructors, this is the empty string.
-   */
-  String name;
-
-  /**
-   * Offset of the executable name relative to the beginning of the file.  For
-   * named constructors, this excludes the class name and excludes the ".".
-   * For unnamed constructors, this is the offset of the class name (i.e. the
-   * offset of the second "C" in "class C { C(); }").
-   */
-  @informative
-  int nameOffset;
-
-  /**
-   * Documentation comment for the executable, or `null` if there is no
-   * documentation comment.
-   */
-  @informative
-  UnlinkedDocumentationComment documentationComment;
-
-  /**
-   * Type parameters of the executable, if any.  Empty if support for generic
-   * method syntax is disabled.
-   */
-  List<UnlinkedTypeParam> typeParameters;
-
-  /**
-   * Declared return type of the executable.  Absent if the executable is a
-   * constructor or the return type is implicit.
-   */
-  EntityRef returnType;
-
-  /**
-   * Parameters of the executable, if any.  Note that getters have no
-   * parameters (hence this will be the empty list), and setters have a single
-   * parameter.
-   */
-  List<UnlinkedParam> parameters;
-
-  /**
-   * The kind of the executable (function/method, getter, setter, or
-   * constructor).
-   */
-  UnlinkedExecutableKind kind;
-
-  /**
-   * Indicates whether the executable is declared using the `abstract` keyword.
-   */
-  bool isAbstract;
-
-  /**
-   * Indicates whether the executable is declared using the `static` keyword.
-   *
-   * Note that for top level executables, this flag is false, since they are
-   * not declared using the `static` keyword (even though they are considered
-   * static for semantic purposes).
-   */
-  bool isStatic;
-
-  /**
-   * Indicates whether the executable is declared using the `const` keyword.
-   */
-  bool isConst;
-
-  /**
-   * Indicates whether the executable is declared using the `factory` keyword.
-   */
-  bool isFactory;
-
-  /**
-   * Indicates whether the executable is declared using the `external` keyword.
-   */
-  bool isExternal;
-
-  /**
-   * If this executable's return type is inferrable, nonzero slot id
-   * identifying which entry in [LinkedLibrary.types] contains the inferred
-   * return type.  If there is no matching entry in [LinkedLibrary.types], then
-   * no return type was inferred for this variable, so its static type is
-   * `dynamic`.
-   */
-  int inferredReturnTypeSlot;
-}
-
-/**
- * Enum used to indicate the kind of an executable.
- */
-enum UnlinkedExecutableKind {
-  /**
-   * Executable is a function or method.
-   */
-  functionOrMethod,
-
-  /**
-   * Executable is a getter.
-   */
-  getter,
-
-  /**
-   * Executable is a setter.
-   */
-  setter,
-
-  /**
-   * Executable is a constructor.
-   */
-  constructor
-}
-
-/**
- * Unlinked summary information about an export declaration (stored outside
- * [UnlinkedPublicNamespace]).
- */
-class UnlinkedExportNonPublic {
-  /**
-   * Offset of the "export" keyword.
-   */
-  @informative
-  int offset;
-
-  /**
-   * Offset of the URI string (including quotes) relative to the beginning of
-   * the file.
-   */
-  @informative
-  int uriOffset;
-
-  /**
-   * End of the URI string (including quotes) relative to the beginning of the
-   * file.
-   */
-  @informative
-  int uriEnd;
-}
-
-/**
- * Unlinked summary information about an export declaration (stored inside
- * [UnlinkedPublicNamespace]).
- */
-class UnlinkedExportPublic {
-  /**
-   * URI used in the source code to reference the exported library.
-   */
-  String uri;
-
-  /**
-   * Combinators contained in this import declaration.
-   */
-  List<UnlinkedCombinator> combinators;
-}
-
-/**
- * Unlinked summary information about an import declaration.
- */
-class UnlinkedImport {
-  /**
-   * URI used in the source code to reference the imported library.
-   */
-  String uri;
-
-  /**
-   * If [isImplicit] is false, offset of the "import" keyword.  If [isImplicit]
-   * is true, zero.
-   */
-  @informative
-  int offset;
-
-  /**
-   * Index into [UnlinkedUnit.references] of the prefix declared by this
-   * import declaration, or zero if this import declaration declares no prefix.
-   *
-   * Note that multiple imports can declare the same prefix.
-   */
-  int prefixReference;
-
-  /**
-   * Combinators contained in this import declaration.
-   */
-  List<UnlinkedCombinator> combinators;
-
-  /**
-   * Indicates whether the import declaration uses the `deferred` keyword.
-   */
-  bool isDeferred;
-
-  /**
-   * Indicates whether the import declaration is implicit.
-   */
-  bool isImplicit;
-
-  /**
-   * Offset of the URI string (including quotes) relative to the beginning of
-   * the file.  If [isImplicit] is true, zero.
-   */
-  @informative
-  int uriOffset;
-
-  /**
-   * End of the URI string (including quotes) relative to the beginning of the
-   * file.  If [isImplicit] is true, zero.
-   */
-  @informative
-  int uriEnd;
-
-  /**
-   * Offset of the prefix name relative to the beginning of the file, or zero
-   * if there is no prefix.
-   */
-  @informative
-  int prefixOffset;
-}
-
-/**
- * Unlinked summary information about a function parameter.
- */
-class UnlinkedParam {
-  /**
-   * Name of the parameter.
-   */
-  String name;
-
-  /**
-   * Offset of the parameter name relative to the beginning of the file.
-   */
-  @informative
-  int nameOffset;
-
-  /**
-   * If [isFunctionTyped] is `true`, the declared return type.  If
-   * [isFunctionTyped] is `false`, the declared type.  Absent if the type is
-   * implicit.
-   */
-  EntityRef type;
-
-  /**
-   * If [isFunctionTyped] is `true`, the parameters of the function type.
-   */
-  List<UnlinkedParam> parameters;
-
-  /**
-   * Kind of the parameter.
-   */
-  UnlinkedParamKind kind;
-
-  /**
-   * Indicates whether this is a function-typed parameter.
-   */
-  bool isFunctionTyped;
-
-  /**
-   * Indicates whether this is an initializing formal parameter (i.e. it is
-   * declared using `this.` syntax).
-   */
-  bool isInitializingFormal;
-
-  /**
-   * If this parameter's type is inferrable, nonzero slot id identifying which
-   * entry in [LinkedLibrary.types] contains the inferred type.  If there is no
-   * matching entry in [LinkedLibrary.types], then no type was inferred for
-   * this variable, so its static type is `dynamic`.
-   *
-   * Note that although strong mode considers initializing formals to be
-   * inferrable, they are not marked as such in the summary; if their type is
-   * not specified, they always inherit the static type of the corresponding
-   * field.
-   */
-  int inferredTypeSlot;
-}
-
-/**
- * Enum used to indicate the kind of a parameter.
- */
-enum UnlinkedParamKind {
-  /**
-   * Parameter is required.
-   */
-  required,
-
-  /**
-   * Parameter is positional optional (enclosed in `[]`)
-   */
-  positional,
-
-  /**
-   * Parameter is named optional (enclosed in `{}`)
-   */
-  named
-}
-
-/**
- * Unlinked summary information about a part declaration.
- */
-class UnlinkedPart {
-  /**
-   * Offset of the URI string (including quotes) relative to the beginning of
-   * the file.
-   */
-  @informative
-  int uriOffset;
-
-  /**
-   * End of the URI string (including quotes) relative to the beginning of the
-   * file.
-   */
-  @informative
-  int uriEnd;
-}
-
-/**
- * Unlinked summary information about a specific name contributed by a
- * compilation unit to a library's public namespace.
- *
- * TODO(paulberry): some of this information is redundant with information
- * elsewhere in the summary.  Consider reducing the redundancy to reduce
- * summary size.
- */
-class UnlinkedPublicName {
-  /**
-   * The name itself.
-   */
-  String name;
-
-  /**
-   * The kind of object referred to by the name.
-   */
-  ReferenceKind kind;
-
-  /**
-   * If the entity being referred to is generic, the number of type parameters
-   * it accepts.  Otherwise zero.
-   */
-  int numTypeParameters;
-
-  /**
-   * If this [UnlinkedPublicName] is a class, the list of members which can be
-   * referenced from constants - static constant fields, static methods, and
-   * constructors.  Otherwise empty.
-   */
-  List<UnlinkedPublicName> constMembers;
-}
-
-/**
- * Unlinked summary information about what a compilation unit contributes to a
- * library's public namespace.  This is the subset of [UnlinkedUnit] that is
- * required from dependent libraries in order to perform prelinking.
- */
-@topLevel
-class UnlinkedPublicNamespace {
-  /**
-   * Public names defined in the compilation unit.
-   *
-   * TODO(paulberry): consider sorting these names to reduce unnecessary
-   * relinking.
-   */
-  List<UnlinkedPublicName> names;
-
-  /**
-   * Export declarations in the compilation unit.
-   */
-  List<UnlinkedExportPublic> exports;
-
-  /**
-   * URIs referenced by part declarations in the compilation unit.
-   */
-  List<String> parts;
-}
-
-/**
- * Unlinked summary information about a name referred to in one library that
- * might be defined in another.
- */
-class 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;
-
-  /**
-   * Prefix used to refer to the entity, or zero if no prefix is used.  This is
-   * an index into [UnlinkedUnit.references].
-   *
-   * Prefix references must always point backward; that is, for all i, if
-   * UnlinkedUnit.references[i].prefixReference != 0, then
-   * UnlinkedUnit.references[i].prefixReference < i.
-   */
-  int prefixReference;
-}
-
-/**
- * Unlinked summary information about a typedef declaration.
- */
-class UnlinkedTypedef {
-  /**
-   * Name of the typedef.
-   */
-  String name;
-
-  /**
-   * Offset of the typedef name relative to the beginning of the file.
-   */
-  @informative
-  int nameOffset;
-
-  /**
-   * Documentation comment for the typedef, or `null` if there is no
-   * documentation comment.
-   */
-  @informative
-  UnlinkedDocumentationComment documentationComment;
-
-  /**
-   * Type parameters of the typedef, if any.
-   */
-  List<UnlinkedTypeParam> typeParameters;
-
-  /**
-   * Return type of the typedef.
-   */
-  EntityRef returnType;
-
-  /**
-   * Parameters of the executable, if any.
-   */
-  List<UnlinkedParam> parameters;
-}
-
-/**
- * Unlinked summary information about a type parameter declaration.
- */
-class UnlinkedTypeParam {
-  /**
-   * Name of the type parameter.
-   */
-  String name;
-
-  /**
-   * Offset of the type parameter name relative to the beginning of the file.
-   */
-  @informative
-  int nameOffset;
-
-  /**
-   * Bound of the type parameter, if a bound is explicitly declared.  Otherwise
-   * null.
-   */
-  EntityRef bound;
-}
-
-/**
- * Unlinked summary information about a compilation unit ("part file").
- */
-@topLevel
-class UnlinkedUnit {
-  /**
-   * Name of the library (from a "library" declaration, if present).
-   */
-  String libraryName;
-
-  /**
-   * Offset of the library name relative to the beginning of the file (or 0 if
-   * the library has no name).
-   */
-  @informative
-  int libraryNameOffset;
-
-  /**
-   * Length of the library name as it appears in the source code (or 0 if the
-   * library has no name).
-   */
-  @informative
-  int libraryNameLength;
-
-  /**
-   * Documentation comment for the library, or `null` if there is no
-   * documentation comment.
-   */
-  @informative
-  UnlinkedDocumentationComment libraryDocumentationComment;
-
-  /**
-   * Unlinked public namespace of this compilation unit.
-   */
-  UnlinkedPublicNamespace publicNamespace;
-
-  /**
-   * Top level and prefixed names referred to by this compilation unit.  The
-   * zeroth element of this array is always populated and is used to represent
-   * the absence of a reference in places where a reference is optional (for
-   * example [UnlinkedReference.prefixReference or
-   * UnlinkedImport.prefixReference]).
-   */
-  List<UnlinkedReference> references;
-
-  /**
-   * Classes declared in the compilation unit.
-   */
-  List<UnlinkedClass> classes;
-
-  /**
-   * Enums declared in the compilation unit.
-   */
-  List<UnlinkedEnum> enums;
-
-  /**
-   * Top level executable objects (functions, getters, and setters) declared in
-   * the compilation unit.
-   */
-  List<UnlinkedExecutable> executables;
-
-  /**
-   * Export declarations in the compilation unit.
-   */
-  List<UnlinkedExportNonPublic> exports;
-
-  /**
-   * Import declarations in the compilation unit.
-   */
-  List<UnlinkedImport> imports;
-
-  /**
-   * Part declarations in the compilation unit.
-   */
-  List<UnlinkedPart> parts;
-
-  /**
-   * Typedefs declared in the compilation unit.
-   */
-  List<UnlinkedTypedef> typedefs;
-
-  /**
-   * Top level variables declared in the compilation unit.
-   */
-  List<UnlinkedVariable> variables;
-}
-
-/**
- * Unlinked summary information about a top level variable, local variable, or
- * a field.
- */
-class UnlinkedVariable {
-  /**
-   * Name of the variable.
-   */
-  String name;
-
-  /**
-   * Offset of the variable name relative to the beginning of the file.
-   */
-  @informative
-  int nameOffset;
-
-  /**
-   * Documentation comment for the variable, or `null` if there is no
-   * documentation comment.
-   */
-  @informative
-  UnlinkedDocumentationComment documentationComment;
-
-  /**
-   * Declared type of the variable.  Absent if the type is implicit.
-   */
-  EntityRef type;
-
-  /**
-   * If [isConst] is true, and the variable has an initializer, the constant
-   * expression in the initializer.
-   */
-  UnlinkedConst constExpr;
-
-  /**
-   * Indicates whether the variable is declared using the `static` keyword.
-   *
-   * Note that for top level variables, this flag is false, since they are not
-   * declared using the `static` keyword (even though they are considered
-   * static for semantic purposes).
-   */
-  bool isStatic;
-
-  /**
-   * Indicates whether the variable is declared using the `final` keyword.
-   */
-  bool isFinal;
-
-  /**
-   * Indicates whether the variable is declared using the `const` keyword.
-   */
-  bool isConst;
-
-  /**
-   * If this variable is propagable, nonzero slot id identifying which entry in
-   * [LinkedLibrary.types] contains the propagated type for this variable.  If
-   * there is no matching entry in [LinkedLibrary.types], then this variable's
-   * propagated type is the same as its declared type.
-   *
-   * Non-propagable variables have a [propagatedTypeSlot] of zero.
-   */
-  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;
-}