Move js library back into compiler directory.

sdk/lib/_internal/lib/foreign_helper.dart

Index: sdk/lib/_internal/lib/foreign_helper.dart
diff --git a/sdk/lib/_internal/lib/foreign_helper.dart b/sdk/lib/_internal/lib/foreign_helper.dart
deleted file mode 100644
index febc75fa8dbe82d4a1ff4f34d91720bf8133c7b4..0000000000000000000000000000000000000000
--- a/sdk/lib/_internal/lib/foreign_helper.dart
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@@ -1,290 +0,0 @@
-// Copyright (c) 2012, 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.
-
-library _foreign_helper;
-
-/**
- * Emits a JavaScript code fragment parameterized by arguments.
- *
- * Hash characters `#` in the [codeTemplate] are replaced in left-to-right order
- * with expressions that contain the values of, or evaluate to, the arguments.
- * The number of hash marks must match the number or arguments.  Although
- * declared with arguments [arg0] through [arg2], the form actually has no limit
- * on the number of arguments.
- *
- * The [typeDescription] argument is interpreted as a description of the
- * behavior of the JavaScript code.  Currently it describes the types that may
- * be returned by the expression, with the additional behavior that the returned
- * values may be fresh instances of the types.  The type information must be
- * correct as it is trusted by the compiler in optimizations, and it must be
- * precise as possible since it is used for native live type analysis to
- * tree-shake large parts of the DOM libraries.  If poorly written, the
- * [typeDescription] will cause unnecessarily bloated programs.  (You can check
- * for this by compiling with `--verbose`; there is an info message describing
- * the number of native (DOM) types that can be removed, which usually should be
- * greater than zero.)
- *
- * The [typeDescription] is a [String] which contains a union of types separated
- * by vertical bar `|` symbols, e.g.  `"num|String"` describes the union of
- * numbers and Strings.  There is no type in Dart that is this precise.  The
- * Dart alternative would be `Object` or `dynamic`, but these types imply that
- * the JS-code might also be creating instances of all the DOM types.  If `null`
- * is possible, it must be specified explicitly, e.g. `"String|Null"`.
- * [typeDescription] has several extensions to help describe the behavior more
- * accurately.  In addition to the union type already described:
- *
- *  + `=Object` is a plain JavaScript object.  Some DOM methods return instances
- *     that have no corresponing Dart type (e.g. cross-frame documents),
- *     `=Object` can be used to describe these untyped' values.
- *
- *  + `var` (or empty string).  If the entire [typeDescription] is `var` (or
- *    empty string) then the type is `dynamic` but the code is known to not
- *    create any instances.
- *
- * Examples:
- *
- *     // Parent window might be an opaque cross-frame window.
- *     var thing = JS('=Object|Window', '#.parent', myWindow);
- *
- * Guidelines:
- *
- *  + Do not use any parameter, local, method or field names in the
- *    [codeTemplate].  These names are all subject to arbitrary renaming by the
- *    compiler.  Pass the values in via `#` substition, and test with the
- *    `--minify` dart2js command-line option.
- *
- *  + The substituted expressions are values, not locations.
- *
- *        JS('void', '# += "x"', this.field);
- *
- *    `this.field` might not be a substituted as a reference to the field.  The
- *    generated code might accidentally work as intended, but it also might be
- *
- *        var t1 = this.field;
- *        t1 += "x";
- *
- *    or
- *
- *        this.get$field() += "x";
- *
- *    The remedy in this case is to expand the `+=` operator, leaving all
- *    references to the Dart field as Dart code:
- *
- *        this.field = JS('String', '# + "x"', this.field);
- *
- *  + Never use `#` in function bodies.
- *
- *    This is a variation on the previous guideline.  Since `#` is replaced with
- *    an *expression* and the expression is only valid in the immediate context,
- *    `#` should never appear in a function body.  Doing so might defer the
- *    evaluation of the expression, and its side effects, until the function is
- *    called.
- *
- *    For example,
- *
- *        var value = foo();
- *        var f = JS('', 'function(){return #}', value)
- *
- *    might result in no immediate call to `foo` and a call to `foo` on every
- *    call to the JavaScript function bound to `f`.  This is better:
- *
- *        var f = JS('',
- *            '(function(val) { return function(){return val}; })(#)', value);
- *
- *    Since `#` occurs in the immediately evaluated expression, the expression
- *    is immediately evaluated and bound to `val` in the immediate call.
- *
- *
- * Additional notes.
- *
- * In the future we may extend [typeDescription] to include other aspects of the
- * behavior, for example, separating the returned types from the instantiated
- * types, or including effects to allow the compiler to perform more
- * optimizations around the code.  This might be an extension of [JS] or a new
- * function similar to [JS] with additional arguments for the new information.
- */
-// Add additional optional arguments if needed. The method is treated internally
-// as a variable argument method.
-JS(String typeDescription, String codeTemplate,
-    [arg0, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11])
-{}
-
-/**
- * Returns the isolate in which this code is running.
- */
-IsolateContext JS_CURRENT_ISOLATE_CONTEXT() {}
-
-abstract class IsolateContext {
-  /// Holds a (native) JavaScript instance of Isolate, see
-  /// finishIsolateConstructorFunction in emitter.dart.
-  get isolateStatics;
-}
-
-/**
- * Invokes [function] in the context of [isolate].
- */
-JS_CALL_IN_ISOLATE(isolate, Function function) {}
-
-/**
- * Converts the Dart closure [function] into a JavaScript closure.
- *
- * Warning: This is no different from [RAW_DART_FUNCTION_REF] which means care
- * must be taken to store the current isolate.
- */
-DART_CLOSURE_TO_JS(Function function) {}
-
-/**
- * Returns a raw reference to the JavaScript function which implements
- * [function].
- *
- * Warning: this is dangerous, you should probably use
- * [DART_CLOSURE_TO_JS] instead. The returned object is not a valid
- * Dart closure, does not store the isolate context or arity.
- *
- * A valid example of where this can be used is as the second argument
- * to V8's Error.captureStackTrace. See
- * https://code.google.com/p/v8/wiki/JavaScriptStackTraceApi.
- */
-RAW_DART_FUNCTION_REF(Function function) {}
-
-/**
- * Sets the current isolate to [isolate].
- */
-void JS_SET_CURRENT_ISOLATE(isolate) {}
-
-/**
- * Creates an isolate and returns it.
- */
-JS_CREATE_ISOLATE() {}
-
-/**
- * Returns the JavaScript constructor function for Dart's Object class.
- * This can be used for type tests, as in
- *
- *     if (JS('bool', '# instanceof #', obj, JS_DART_OBJECT_CONSTRUCTOR()))
- *       ...
- */
-JS_DART_OBJECT_CONSTRUCTOR() {}
-
-/**
- * Returns the interceptor for class [type].  The interceptor is the type's
- * constructor's `prototype` property.  [type] will typically be the class, not
- * an interface, e.g. `JS_INTERCEPTOR_CONSTANT(JSInt)`, not
- * `JS_INTERCEPTOR_CONSTANT(int)`.
- */
-JS_INTERCEPTOR_CONSTANT(Type type) {}
-
-/**
- * Returns the prefix used for generated is checks on classes.
- */
-String JS_OPERATOR_IS_PREFIX() {}
-
-/**
- * Returns the prefix used for generated type argument substitutions on classes.
- */
-String JS_OPERATOR_AS_PREFIX() {}
-
-/// Returns the name of the class `Object` in the generated code.
-String JS_OBJECT_CLASS_NAME() {}
-
-/// Returns the name of the class `Null` in the generated code.
-String JS_NULL_CLASS_NAME() {}
-
-/// Returns the name of the class `Function` in the generated code.
-String JS_FUNCTION_CLASS_NAME() {}
-
-/**
- * Returns the field name used for determining if an object or its
- * interceptor has JavaScript indexing behavior.
- */
-String JS_IS_INDEXABLE_FIELD_NAME() {}
-
-/**
- * Returns the object corresponding to Namer.CURRENT_ISOLATE.
- */
-JS_CURRENT_ISOLATE() {}
-
-/// Returns the name used for generated function types on classes and methods.
-String JS_SIGNATURE_NAME() {}
-
-/// Returns the name used to tag function type representations in JavaScript.
-String JS_FUNCTION_TYPE_TAG() {}
-
-/**
- * Returns the name used to tag void return in function type representations
- * in JavaScript.
- */
-String JS_FUNCTION_TYPE_VOID_RETURN_TAG() {}
-
-/**
- * Returns the name used to tag return types in function type representations
- * in JavaScript.
- */
-String JS_FUNCTION_TYPE_RETURN_TYPE_TAG() {}
-
-/**
- * Returns the name used to tag required parameters in function type
- * representations in JavaScript.
- */
-String JS_FUNCTION_TYPE_REQUIRED_PARAMETERS_TAG() {}
-
-/**
- * Returns the name used to tag optional parameters in function type
- * representations in JavaScript.
- */
-String JS_FUNCTION_TYPE_OPTIONAL_PARAMETERS_TAG() {}
-
-/**
- * Returns the name used to tag named parameters in function type
- * representations in JavaScript.
- */
-String JS_FUNCTION_TYPE_NAMED_PARAMETERS_TAG() {}
-
-/**
- * Obtain [name] from Namer.
- */
-String JS_GET_NAME(String name) {}
-
-/// Returns the state of a flag that is determined by the state of the compiler
-/// when the program has been analyzed.
-bool JS_GET_FLAG(String name) {}
-
-/**
- * Pretend [code] is executed.  Generates no executable code.  This is used to
- * model effects at some other point in external code.  For example, the
- * following models an assignment to foo with an unknown value.
- *
- *     var foo;
- *
- *     main() {
- *       JS_EFFECT((_){ foo = _; })
- *     }
- *
- * TODO(sra): Replace this hack with something to mark the volatile or
- * externally initialized elements.
- */
-void JS_EFFECT(Function code) { code(null); }
-
-/**
- * Use this class for creating constants that hold JavaScript code.
- * For example:
- *
- * const constant = JS_CONST('typeof window != "undefined");
- *
- * This code will generate:
- * $.JS_CONST_1 = typeof window != "undefined";
- */
-class JS_CONST {
-  final String code;
-  const JS_CONST(this.code);
-}
-
-/**
- * JavaScript string concatenation. Inputs must be Strings.  Corresponds to the
- * HStringConcat SSA instruction and may be constant-folded.
- */
-String JS_STRING_CONCAT(String a, String b) {
-  // This body is unused, only here for type analysis.
-  return JS('String', '# + #', a, b);
-}