1 // Copyright 2007, Google Inc.
2 // All rights reserved.
3 //
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5 // modification, are permitted provided that the following conditions are
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7 //
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17 //
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28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29
30
31 // Google Mock - a framework for writing C++ mock classes.
32 //
33 // This file implements some commonly used actions.
34
35 // GOOGLETEST_CM0002 DO NOT DELETE
36
37 #ifndef GMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_
38 #define GMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_
39
40 #ifndef _WIN32_WCE
41 # include <errno.h>
42 #endif
43
44 #include <algorithm>
45 #include <string>
46
47 #include "gmock/internal/gmock-internal-utils.h"
48 #include "gmock/internal/gmock-port.h"
49
50 #if GTEST_LANG_CXX11 // Defined by gtest-port.h via gmock-port.h.
51 #include <functional>
52 #include <type_traits>
53 #endif // GTEST_LANG_CXX11
54
55 namespace testing {
56
57 // To implement an action Foo, define:
58 // 1. a class FooAction that implements the ActionInterface interface, and
59 // 2. a factory function that creates an Action object from a
60 // const FooAction*.
61 //
62 // The two-level delegation design follows that of Matcher, providing
63 // consistency for extension developers. It also eases ownership
64 // management as Action objects can now be copied like plain values.
65
66 namespace internal {
67
68 template <typename F1, typename F2>
69 class ActionAdaptor;
70
71 // BuiltInDefaultValueGetter<T, true>::Get() returns a
72 // default-constructed T value. BuiltInDefaultValueGetter<T,
73 // false>::Get() crashes with an error.
74 //
75 // This primary template is used when kDefaultConstructible is true.
76 template <typename T, bool kDefaultConstructible>
77 struct BuiltInDefaultValueGetter {
78 static T Get() { return T(); }
79 };
80 template <typename T>
81 struct BuiltInDefaultValueGetter<T, false> {
82 static T Get() {
83 Assert(false, __FILE__, __LINE__,
84 "Default action undefined for the function return type.");
85 return internal::Invalid<T>();
86 // The above statement will never be reached, but is required in
87 // order for this function to compile.
88 }
89 };
90
91 // BuiltInDefaultValue<T>::Get() returns the "built-in" default value
92 // for type T, which is NULL when T is a raw pointer type, 0 when T is
93 // a numeric type, false when T is bool, or "" when T is string or
94 // std::string. In addition, in C++11 and above, it turns a
95 // default-constructed T value if T is default constructible. For any
96 // other type T, the built-in default T value is undefined, and the
97 // function will abort the process.
98 template <typename T>
99 class BuiltInDefaultValue {
100 public:
101 #if GTEST_LANG_CXX11
102 // This function returns true iff type T has a built-in default value.
103 static bool Exists() {
104 return ::std::is_default_constructible<T>::value;
105 }
106
107 static T Get() {
108 return BuiltInDefaultValueGetter<
109 T, ::std::is_default_constructible<T>::value>::Get();
110 }
111
112 #else // GTEST_LANG_CXX11
113 // This function returns true iff type T has a built-in default value.
114 static bool Exists() {
115 return false;
116 }
117
118 static T Get() {
119 return BuiltInDefaultValueGetter<T, false>::Get();
120 }
121
122 #endif // GTEST_LANG_CXX11
123 };
124
125 // This partial specialization says that we use the same built-in
126 // default value for T and const T.
127 template <typename T>
128 class BuiltInDefaultValue<const T> {
129 public:
130 static bool Exists() { return BuiltInDefaultValue<T>::Exists(); }
131 static T Get() { return BuiltInDefaultValue<T>::Get(); }
132 };
133
134 // This partial specialization defines the default values for pointer
135 // types.
136 template <typename T>
137 class BuiltInDefaultValue<T*> {
138 public:
139 static bool Exists() { return true; }
140 static T* Get() { return NULL; }
141 };
142
143 // The following specializations define the default values for
144 // specific types we care about.
145 #define GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(type, value) \
146 template <> \
147 class BuiltInDefaultValue<type> { \
148 public: \
149 static bool Exists() { return true; } \
150 static type Get() { return value; } \
151 }
152
153 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(void, ); // NOLINT
154 #if GTEST_HAS_GLOBAL_STRING
155 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(::string, "");
156 #endif // GTEST_HAS_GLOBAL_STRING
157 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(::std::string, "");
158 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(bool, false);
159 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned char, '\0');
160 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed char, '\0');
161 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(char, '\0');
162
163 // There's no need for a default action for signed wchar_t, as that
164 // type is the same as wchar_t for gcc, and invalid for MSVC.
165 //
166 // There's also no need for a default action for unsigned wchar_t, as
167 // that type is the same as unsigned int for gcc, and invalid for
168 // MSVC.
169 #if GMOCK_WCHAR_T_IS_NATIVE_
170 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(wchar_t, 0U); // NOLINT
171 #endif
172
173 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned short, 0U); // NOLINT
174 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed short, 0); // NOLINT
175 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned int, 0U);
176 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed int, 0);
177 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(unsigned long, 0UL); // NOLINT
178 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(signed long, 0L); // NOLINT
179 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(UInt64, 0);
180 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(Int64, 0);
181 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(float, 0);
182 GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_(double, 0);
183
184 #undef GMOCK_DEFINE_DEFAULT_ACTION_FOR_RETURN_TYPE_
185
186 } // namespace internal
187
188 // When an unexpected function call is encountered, Google Mock will
189 // let it return a default value if the user has specified one for its
190 // return type, or if the return type has a built-in default value;
191 // otherwise Google Mock won't know what value to return and will have
192 // to abort the process.
193 //
194 // The DefaultValue<T> class allows a user to specify the
195 // default value for a type T that is both copyable and publicly
196 // destructible (i.e. anything that can be used as a function return
197 // type). The usage is:
198 //
199 // // Sets the default value for type T to be foo.
200 // DefaultValue<T>::Set(foo);
201 template <typename T>
202 class DefaultValue {
203 public:
204 // Sets the default value for type T; requires T to be
205 // copy-constructable and have a public destructor.
206 static void Set(T x) {
207 delete producer_;
208 producer_ = new FixedValueProducer(x);
209 }
210
211 // Provides a factory function to be called to generate the default value.
212 // This method can be used even if T is only move-constructible, but it is not
213 // limited to that case.
214 typedef T (*FactoryFunction)();
215 static void SetFactory(FactoryFunction factory) {
216 delete producer_;
217 producer_ = new FactoryValueProducer(factory);
218 }
219
220 // Unsets the default value for type T.
221 static void Clear() {
222 delete producer_;
223 producer_ = NULL;
224 }
225
226 // Returns true iff the user has set the default value for type T.
227 static bool IsSet() { return producer_ != NULL; }
228
229 // Returns true if T has a default return value set by the user or there
230 // exists a built-in default value.
231 static bool Exists() {
232 return IsSet() || internal::BuiltInDefaultValue<T>::Exists();
233 }
234
235 // Returns the default value for type T if the user has set one;
236 // otherwise returns the built-in default value. Requires that Exists()
237 // is true, which ensures that the return value is well-defined.
238 static T Get() {
239 return producer_ == NULL ?
240 internal::BuiltInDefaultValue<T>::Get() : producer_->Produce();
241 }
242
243 private:
244 class ValueProducer {
245 public:
246 virtual ~ValueProducer() {}
247 virtual T Produce() = 0;
248 };
249
250 class FixedValueProducer : public ValueProducer {
251 public:
252 explicit FixedValueProducer(T value) : value_(value) {}
253 virtual T Produce() { return value_; }
254
255 private:
256 const T value_;
257 GTEST_DISALLOW_COPY_AND_ASSIGN_(FixedValueProducer);
258 };
259
260 class FactoryValueProducer : public ValueProducer {
261 public:
262 explicit FactoryValueProducer(FactoryFunction factory)
263 : factory_(factory) {}
264 virtual T Produce() { return factory_(); }
265
266 private:
267 const FactoryFunction factory_;
268 GTEST_DISALLOW_COPY_AND_ASSIGN_(FactoryValueProducer);
269 };
270
271 static ValueProducer* producer_;
272 };
273
274 // This partial specialization allows a user to set default values for
275 // reference types.
276 template <typename T>
277 class DefaultValue<T&> {
278 public:
279 // Sets the default value for type T&.
280 static void Set(T& x) { // NOLINT
281 address_ = &x;
282 }
283
284 // Unsets the default value for type T&.
285 static void Clear() {
286 address_ = NULL;
287 }
288
289 // Returns true iff the user has set the default value for type T&.
290 static bool IsSet() { return address_ != NULL; }
291
292 // Returns true if T has a default return value set by the user or there
293 // exists a built-in default value.
294 static bool Exists() {
295 return IsSet() || internal::BuiltInDefaultValue<T&>::Exists();
296 }
297
298 // Returns the default value for type T& if the user has set one;
299 // otherwise returns the built-in default value if there is one;
300 // otherwise aborts the process.
301 static T& Get() {
302 return address_ == NULL ?
303 internal::BuiltInDefaultValue<T&>::Get() : *address_;
304 }
305
306 private:
307 static T* address_;
308 };
309
310 // This specialization allows DefaultValue<void>::Get() to
311 // compile.
312 template <>
313 class DefaultValue<void> {
314 public:
315 static bool Exists() { return true; }
316 static void Get() {}
317 };
318
319 // Points to the user-set default value for type T.
320 template <typename T>
321 typename DefaultValue<T>::ValueProducer* DefaultValue<T>::producer_ = NULL;
322
323 // Points to the user-set default value for type T&.
324 template <typename T>
325 T* DefaultValue<T&>::address_ = NULL;
326
327 // Implement this interface to define an action for function type F.
328 template <typename F>
329 class ActionInterface {
330 public:
331 typedef typename internal::Function<F>::Result Result;
332 typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;
333
334 ActionInterface() {}
335 virtual ~ActionInterface() {}
336
337 // Performs the action. This method is not const, as in general an
338 // action can have side effects and be stateful. For example, a
339 // get-the-next-element-from-the-collection action will need to
340 // remember the current element.
341 virtual Result Perform(const ArgumentTuple& args) = 0;
342
343 private:
344 GTEST_DISALLOW_COPY_AND_ASSIGN_(ActionInterface);
345 };
346
347 // An Action<F> is a copyable and IMMUTABLE (except by assignment)
348 // object that represents an action to be taken when a mock function
349 // of type F is called. The implementation of Action<T> is just a
350 // linked_ptr to const ActionInterface<T>, so copying is fairly cheap.
351 // Don't inherit from Action!
352 //
353 // You can view an object implementing ActionInterface<F> as a
354 // concrete action (including its current state), and an Action<F>
355 // object as a handle to it.
356 template <typename F>
357 class Action {
358 public:
359 typedef typename internal::Function<F>::Result Result;
360 typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;
361
362 // Constructs a null Action. Needed for storing Action objects in
363 // STL containers.
364 Action() {}
365
366 #if GTEST_LANG_CXX11
367 // Construct an Action from a specified callable.
368 // This cannot take std::function directly, because then Action would not be
369 // directly constructible from lambda (it would require two conversions).
370 template <typename G,
371 typename = typename ::std::enable_if<
372 ::std::is_constructible<::std::function<F>, G>::value>::type>
373 Action(G&& fun) : fun_(::std::forward<G>(fun)) {} // NOLINT
374 #endif
375
376 // Constructs an Action from its implementation.
377 explicit Action(ActionInterface<F>* impl) : impl_(impl) {}
378
379 // This constructor allows us to turn an Action<Func> object into an
380 // Action<F>, as long as F's arguments can be implicitly converted
381 // to Func's and Func's return type can be implicitly converted to
382 // F's.
383 template <typename Func>
384 explicit Action(const Action<Func>& action);
385
386 // Returns true iff this is the DoDefault() action.
387 bool IsDoDefault() const {
388 #if GTEST_LANG_CXX11
389 return impl_ == nullptr && fun_ == nullptr;
390 #else
391 return impl_ == NULL;
392 #endif
393 }
394
395 // Performs the action. Note that this method is const even though
396 // the corresponding method in ActionInterface is not. The reason
397 // is that a const Action<F> means that it cannot be re-bound to
398 // another concrete action, not that the concrete action it binds to
399 // cannot change state. (Think of the difference between a const
400 // pointer and a pointer to const.)
401 Result Perform(ArgumentTuple args) const {
402 if (IsDoDefault()) {
403 internal::IllegalDoDefault(__FILE__, __LINE__);
404 }
405 #if GTEST_LANG_CXX11
406 if (fun_ != nullptr) {
407 return internal::Apply(fun_, ::std::move(args));
408 }
409 #endif
410 return impl_->Perform(args);
411 }
412
413 private:
414 template <typename F1, typename F2>
415 friend class internal::ActionAdaptor;
416
417 template <typename G>
418 friend class Action;
419
420 // In C++11, Action can be implemented either as a generic functor (through
421 // std::function), or legacy ActionInterface. In C++98, only ActionInterface
422 // is available. The invariants are as follows:
423 // * in C++98, impl_ is null iff this is the default action
424 // * in C++11, at most one of fun_ & impl_ may be nonnull; both are null iff
425 // this is the default action
426 #if GTEST_LANG_CXX11
427 ::std::function<F> fun_;
428 #endif
429 internal::linked_ptr<ActionInterface<F> > impl_;
430 };
431
432 // The PolymorphicAction class template makes it easy to implement a
433 // polymorphic action (i.e. an action that can be used in mock
434 // functions of than one type, e.g. Return()).
435 //
436 // To define a polymorphic action, a user first provides a COPYABLE
437 // implementation class that has a Perform() method template:
438 //
439 // class FooAction {
440 // public:
441 // template <typename Result, typename ArgumentTuple>
442 // Result Perform(const ArgumentTuple& args) const {
443 // // Processes the arguments and returns a result, using
444 // // tr1::get<N>(args) to get the N-th (0-based) argument in the tuple.
445 // }
446 // ...
447 // };
448 //
449 // Then the user creates the polymorphic action using
450 // MakePolymorphicAction(object) where object has type FooAction. See
451 // the definition of Return(void) and SetArgumentPointee<N>(value) for
452 // complete examples.
453 template <typename Impl>
454 class PolymorphicAction {
455 public:
456 explicit PolymorphicAction(const Impl& impl) : impl_(impl) {}
457
458 template <typename F>
459 operator Action<F>() const {
460 return Action<F>(new MonomorphicImpl<F>(impl_));
461 }
462
463 private:
464 template <typename F>
465 class MonomorphicImpl : public ActionInterface<F> {
466 public:
467 typedef typename internal::Function<F>::Result Result;
468 typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;
469
470 explicit MonomorphicImpl(const Impl& impl) : impl_(impl) {}
471
472 virtual Result Perform(const ArgumentTuple& args) {
473 return impl_.template Perform<Result>(args);
474 }
475
476 private:
477 Impl impl_;
478
479 GTEST_DISALLOW_ASSIGN_(MonomorphicImpl);
480 };
481
482 Impl impl_;
483
484 GTEST_DISALLOW_ASSIGN_(PolymorphicAction);
485 };
486
487 // Creates an Action from its implementation and returns it. The
488 // created Action object owns the implementation.
489 template <typename F>
490 Action<F> MakeAction(ActionInterface<F>* impl) {
491 return Action<F>(impl);
492 }
493
494 // Creates a polymorphic action from its implementation. This is
495 // easier to use than the PolymorphicAction<Impl> constructor as it
496 // doesn't require you to explicitly write the template argument, e.g.
497 //
498 // MakePolymorphicAction(foo);
499 // vs
500 // PolymorphicAction<TypeOfFoo>(foo);
501 template <typename Impl>
502 inline PolymorphicAction<Impl> MakePolymorphicAction(const Impl& impl) {
503 return PolymorphicAction<Impl>(impl);
504 }
505
506 namespace internal {
507
508 // Allows an Action<F2> object to pose as an Action<F1>, as long as F2
509 // and F1 are compatible.
510 template <typename F1, typename F2>
511 class ActionAdaptor : public ActionInterface<F1> {
512 public:
513 typedef typename internal::Function<F1>::Result Result;
514 typedef typename internal::Function<F1>::ArgumentTuple ArgumentTuple;
515
516 explicit ActionAdaptor(const Action<F2>& from) : impl_(from.impl_) {}
517
518 virtual Result Perform(const ArgumentTuple& args) {
519 return impl_->Perform(args);
520 }
521
522 private:
523 const internal::linked_ptr<ActionInterface<F2> > impl_;
524
525 GTEST_DISALLOW_ASSIGN_(ActionAdaptor);
526 };
527
528 // Helper struct to specialize ReturnAction to execute a move instead of a copy
529 // on return. Useful for move-only types, but could be used on any type.
530 template <typename T>
531 struct ByMoveWrapper {
532 explicit ByMoveWrapper(T value) : payload(internal::move(value)) {}
533 T payload;
534 };
535
536 // Implements the polymorphic Return(x) action, which can be used in
537 // any function that returns the type of x, regardless of the argument
538 // types.
539 //
540 // Note: The value passed into Return must be converted into
541 // Function<F>::Result when this action is cast to Action<F> rather than
542 // when that action is performed. This is important in scenarios like
543 //
544 // MOCK_METHOD1(Method, T(U));
545 // ...
546 // {
547 // Foo foo;
548 // X x(&foo);
549 // EXPECT_CALL(mock, Method(_)).WillOnce(Return(x));
550 // }
551 //
552 // In the example above the variable x holds reference to foo which leaves
553 // scope and gets destroyed. If copying X just copies a reference to foo,
554 // that copy will be left with a hanging reference. If conversion to T
555 // makes a copy of foo, the above code is safe. To support that scenario, we
556 // need to make sure that the type conversion happens inside the EXPECT_CALL
557 // statement, and conversion of the result of Return to Action<T(U)> is a
558 // good place for that.
559 //
560 // The real life example of the above scenario happens when an invocation
561 // of gtl::Container() is passed into Return.
562 //
563 template <typename R>
564 class ReturnAction {
565 public:
566 // Constructs a ReturnAction object from the value to be returned.
567 // 'value' is passed by value instead of by const reference in order
568 // to allow Return("string literal") to compile.
569 explicit ReturnAction(R value) : value_(new R(internal::move(value))) {}
570
571 // This template type conversion operator allows Return(x) to be
572 // used in ANY function that returns x's type.
573 template <typename F>
574 operator Action<F>() const {
575 // Assert statement belongs here because this is the best place to verify
576 // conditions on F. It produces the clearest error messages
577 // in most compilers.
578 // Impl really belongs in this scope as a local class but can't
579 // because MSVC produces duplicate symbols in different translation units
580 // in this case. Until MS fixes that bug we put Impl into the class scope
581 // and put the typedef both here (for use in assert statement) and
582 // in the Impl class. But both definitions must be the same.
583 typedef typename Function<F>::Result Result;
584 GTEST_COMPILE_ASSERT_(
585 !is_reference<Result>::value,
586 use_ReturnRef_instead_of_Return_to_return_a_reference);
587 return Action<F>(new Impl<R, F>(value_));
588 }
589
590 private:
591 // Implements the Return(x) action for a particular function type F.
592 template <typename R_, typename F>
593 class Impl : public ActionInterface<F> {
594 public:
595 typedef typename Function<F>::Result Result;
596 typedef typename Function<F>::ArgumentTuple ArgumentTuple;
597
598 // The implicit cast is necessary when Result has more than one
599 // single-argument constructor (e.g. Result is std::vector<int>) and R
600 // has a type conversion operator template. In that case, value_(value)
601 // won't compile as the compiler doesn't known which constructor of
602 // Result to call. ImplicitCast_ forces the compiler to convert R to
603 // Result without considering explicit constructors, thus resolving the
604 // ambiguity. value_ is then initialized using its copy constructor.
605 explicit Impl(const linked_ptr<R>& value)
606 : value_before_cast_(*value),
607 value_(ImplicitCast_<Result>(value_before_cast_)) {}
608
609 virtual Result Perform(const ArgumentTuple&) { return value_; }
610
611 private:
612 GTEST_COMPILE_ASSERT_(!is_reference<Result>::value,
613 Result_cannot_be_a_reference_type);
614 // We save the value before casting just in case it is being cast to a
615 // wrapper type.
616 R value_before_cast_;
617 Result value_;
618
619 GTEST_DISALLOW_COPY_AND_ASSIGN_(Impl);
620 };
621
622 // Partially specialize for ByMoveWrapper. This version of ReturnAction will
623 // move its contents instead.
624 template <typename R_, typename F>
625 class Impl<ByMoveWrapper<R_>, F> : public ActionInterface<F> {
626 public:
627 typedef typename Function<F>::Result Result;
628 typedef typename Function<F>::ArgumentTuple ArgumentTuple;
629
630 explicit Impl(const linked_ptr<R>& wrapper)
631 : performed_(false), wrapper_(wrapper) {}
632
633 virtual Result Perform(const ArgumentTuple&) {
634 GTEST_CHECK_(!performed_)
635 << "A ByMove() action should only be performed once.";
636 performed_ = true;
637 return internal::move(wrapper_->payload);
638 }
639
640 private:
641 bool performed_;
642 const linked_ptr<R> wrapper_;
643
644 GTEST_DISALLOW_ASSIGN_(Impl);
645 };
646
647 const linked_ptr<R> value_;
648
649 GTEST_DISALLOW_ASSIGN_(ReturnAction);
650 };
651
652 // Implements the ReturnNull() action.
653 class ReturnNullAction {
654 public:
655 // Allows ReturnNull() to be used in any pointer-returning function. In C++11
656 // this is enforced by returning nullptr, and in non-C++11 by asserting a
657 // pointer type on compile time.
658 template <typename Result, typename ArgumentTuple>
659 static Result Perform(const ArgumentTuple&) {
660 #if GTEST_LANG_CXX11
661 return nullptr;
662 #else
663 GTEST_COMPILE_ASSERT_(internal::is_pointer<Result>::value,
664 ReturnNull_can_be_used_to_return_a_pointer_only);
665 return NULL;
666 #endif // GTEST_LANG_CXX11
667 }
668 };
669
670 // Implements the Return() action.
671 class ReturnVoidAction {
672 public:
673 // Allows Return() to be used in any void-returning function.
674 template <typename Result, typename ArgumentTuple>
675 static void Perform(const ArgumentTuple&) {
676 CompileAssertTypesEqual<void, Result>();
677 }
678 };
679
680 // Implements the polymorphic ReturnRef(x) action, which can be used
681 // in any function that returns a reference to the type of x,
682 // regardless of the argument types.
683 template <typename T>
684 class ReturnRefAction {
685 public:
686 // Constructs a ReturnRefAction object from the reference to be returned.
687 explicit ReturnRefAction(T& ref) : ref_(ref) {} // NOLINT
688
689 // This template type conversion operator allows ReturnRef(x) to be
690 // used in ANY function that returns a reference to x's type.
691 template <typename F>
692 operator Action<F>() const {
693 typedef typename Function<F>::Result Result;
694 // Asserts that the function return type is a reference. This
695 // catches the user error of using ReturnRef(x) when Return(x)
696 // should be used, and generates some helpful error message.
697 GTEST_COMPILE_ASSERT_(internal::is_reference<Result>::value,
698 use_Return_instead_of_ReturnRef_to_return_a_value);
699 return Action<F>(new Impl<F>(ref_));
700 }
701
702 private:
703 // Implements the ReturnRef(x) action for a particular function type F.
704 template <typename F>
705 class Impl : public ActionInterface<F> {
706 public:
707 typedef typename Function<F>::Result Result;
708 typedef typename Function<F>::ArgumentTuple ArgumentTuple;
709
710 explicit Impl(T& ref) : ref_(ref) {} // NOLINT
711
712 virtual Result Perform(const ArgumentTuple&) {
713 return ref_;
714 }
715
716 private:
717 T& ref_;
718
719 GTEST_DISALLOW_ASSIGN_(Impl);
720 };
721
722 T& ref_;
723
724 GTEST_DISALLOW_ASSIGN_(ReturnRefAction);
725 };
726
727 // Implements the polymorphic ReturnRefOfCopy(x) action, which can be
728 // used in any function that returns a reference to the type of x,
729 // regardless of the argument types.
730 template <typename T>
731 class ReturnRefOfCopyAction {
732 public:
733 // Constructs a ReturnRefOfCopyAction object from the reference to
734 // be returned.
735 explicit ReturnRefOfCopyAction(const T& value) : value_(value) {} // NOLINT
736
737 // This template type conversion operator allows ReturnRefOfCopy(x) to be
738 // used in ANY function that returns a reference to x's type.
739 template <typename F>
740 operator Action<F>() const {
741 typedef typename Function<F>::Result Result;
742 // Asserts that the function return type is a reference. This
743 // catches the user error of using ReturnRefOfCopy(x) when Return(x)
744 // should be used, and generates some helpful error message.
745 GTEST_COMPILE_ASSERT_(
746 internal::is_reference<Result>::value,
747 use_Return_instead_of_ReturnRefOfCopy_to_return_a_value);
748 return Action<F>(new Impl<F>(value_));
749 }
750
751 private:
752 // Implements the ReturnRefOfCopy(x) action for a particular function type F.
753 template <typename F>
754 class Impl : public ActionInterface<F> {
755 public:
756 typedef typename Function<F>::Result Result;
757 typedef typename Function<F>::ArgumentTuple ArgumentTuple;
758
759 explicit Impl(const T& value) : value_(value) {} // NOLINT
760
761 virtual Result Perform(const ArgumentTuple&) {
762 return value_;
763 }
764
765 private:
766 T value_;
767
768 GTEST_DISALLOW_ASSIGN_(Impl);
769 };
770
771 const T value_;
772
773 GTEST_DISALLOW_ASSIGN_(ReturnRefOfCopyAction);
774 };
775
776 // Implements the polymorphic DoDefault() action.
777 class DoDefaultAction {
778 public:
779 // This template type conversion operator allows DoDefault() to be
780 // used in any function.
781 template <typename F>
782 operator Action<F>() const { return Action<F>(); } // NOLINT
783 };
784
785 // Implements the Assign action to set a given pointer referent to a
786 // particular value.
787 template <typename T1, typename T2>
788 class AssignAction {
789 public:
790 AssignAction(T1* ptr, T2 value) : ptr_(ptr), value_(value) {}
791
792 template <typename Result, typename ArgumentTuple>
793 void Perform(const ArgumentTuple& /* args */) const {
794 *ptr_ = value_;
795 }
796
797 private:
798 T1* const ptr_;
799 const T2 value_;
800
801 GTEST_DISALLOW_ASSIGN_(AssignAction);
802 };
803
804 #if !GTEST_OS_WINDOWS_MOBILE
805
806 // Implements the SetErrnoAndReturn action to simulate return from
807 // various system calls and libc functions.
808 template <typename T>
809 class SetErrnoAndReturnAction {
810 public:
811 SetErrnoAndReturnAction(int errno_value, T result)
812 : errno_(errno_value),
813 result_(result) {}
814 template <typename Result, typename ArgumentTuple>
815 Result Perform(const ArgumentTuple& /* args */) const {
816 errno = errno_;
817 return result_;
818 }
819
820 private:
821 const int errno_;
822 const T result_;
823
824 GTEST_DISALLOW_ASSIGN_(SetErrnoAndReturnAction);
825 };
826
827 #endif // !GTEST_OS_WINDOWS_MOBILE
828
829 // Implements the SetArgumentPointee<N>(x) action for any function
830 // whose N-th argument (0-based) is a pointer to x's type. The
831 // template parameter kIsProto is true iff type A is ProtocolMessage,
832 // proto2::Message, or a sub-class of those.
833 template <size_t N, typename A, bool kIsProto>
834 class SetArgumentPointeeAction {
835 public:
836 // Constructs an action that sets the variable pointed to by the
837 // N-th function argument to 'value'.
838 explicit SetArgumentPointeeAction(const A& value) : value_(value) {}
839
840 template <typename Result, typename ArgumentTuple>
841 void Perform(const ArgumentTuple& args) const {
842 CompileAssertTypesEqual<void, Result>();
843 *::testing::get<N>(args) = value_;
844 }
845
846 private:
847 const A value_;
848
849 GTEST_DISALLOW_ASSIGN_(SetArgumentPointeeAction);
850 };
851
852 template <size_t N, typename Proto>
853 class SetArgumentPointeeAction<N, Proto, true> {
854 public:
855 // Constructs an action that sets the variable pointed to by the
856 // N-th function argument to 'proto'. Both ProtocolMessage and
857 // proto2::Message have the CopyFrom() method, so the same
858 // implementation works for both.
859 explicit SetArgumentPointeeAction(const Proto& proto) : proto_(new Proto) {
860 proto_->CopyFrom(proto);
861 }
862
863 template <typename Result, typename ArgumentTuple>
864 void Perform(const ArgumentTuple& args) const {
865 CompileAssertTypesEqual<void, Result>();
866 ::testing::get<N>(args)->CopyFrom(*proto_);
867 }
868
869 private:
870 const internal::linked_ptr<Proto> proto_;
871
872 GTEST_DISALLOW_ASSIGN_(SetArgumentPointeeAction);
873 };
874
875 // Implements the InvokeWithoutArgs(f) action. The template argument
876 // FunctionImpl is the implementation type of f, which can be either a
877 // function pointer or a functor. InvokeWithoutArgs(f) can be used as an
878 // Action<F> as long as f's type is compatible with F (i.e. f can be
879 // assigned to a tr1::function<F>).
880 template <typename FunctionImpl>
881 class InvokeWithoutArgsAction {
882 public:
883 // The c'tor makes a copy of function_impl (either a function
884 // pointer or a functor).
885 explicit InvokeWithoutArgsAction(FunctionImpl function_impl)
886 : function_impl_(function_impl) {}
887
888 // Allows InvokeWithoutArgs(f) to be used as any action whose type is
889 // compatible with f.
890 template <typename Result, typename ArgumentTuple>
891 Result Perform(const ArgumentTuple&) { return function_impl_(); }
892
893 private:
894 FunctionImpl function_impl_;
895
896 GTEST_DISALLOW_ASSIGN_(InvokeWithoutArgsAction);
897 };
898
899 // Implements the InvokeWithoutArgs(object_ptr, &Class::Method) action.
900 template <class Class, typename MethodPtr>
901 class InvokeMethodWithoutArgsAction {
902 public:
903 InvokeMethodWithoutArgsAction(Class* obj_ptr, MethodPtr method_ptr)
904 : obj_ptr_(obj_ptr), method_ptr_(method_ptr) {}
905
906 template <typename Result, typename ArgumentTuple>
907 Result Perform(const ArgumentTuple&) const {
908 return (obj_ptr_->*method_ptr_)();
909 }
910
911 private:
912 Class* const obj_ptr_;
913 const MethodPtr method_ptr_;
914
915 GTEST_DISALLOW_ASSIGN_(InvokeMethodWithoutArgsAction);
916 };
917
918 // Implements the InvokeWithoutArgs(callback) action.
919 template <typename CallbackType>
920 class InvokeCallbackWithoutArgsAction {
921 public:
922 // The c'tor takes ownership of the callback.
923 explicit InvokeCallbackWithoutArgsAction(CallbackType* callback)
924 : callback_(callback) {
925 callback->CheckIsRepeatable(); // Makes sure the callback is permanent.
926 }
927
928 // This type conversion operator template allows Invoke(callback) to
929 // be used wherever the callback's return type can be implicitly
930 // converted to that of the mock function.
931 template <typename Result, typename ArgumentTuple>
932 Result Perform(const ArgumentTuple&) const { return callback_->Run(); }
933
934 private:
935 const internal::linked_ptr<CallbackType> callback_;
936
937 GTEST_DISALLOW_ASSIGN_(InvokeCallbackWithoutArgsAction);
938 };
939
940 // Implements the IgnoreResult(action) action.
941 template <typename A>
942 class IgnoreResultAction {
943 public:
944 explicit IgnoreResultAction(const A& action) : action_(action) {}
945
946 template <typename F>
947 operator Action<F>() const {
948 // Assert statement belongs here because this is the best place to verify
949 // conditions on F. It produces the clearest error messages
950 // in most compilers.
951 // Impl really belongs in this scope as a local class but can't
952 // because MSVC produces duplicate symbols in different translation units
953 // in this case. Until MS fixes that bug we put Impl into the class scope
954 // and put the typedef both here (for use in assert statement) and
955 // in the Impl class. But both definitions must be the same.
956 typedef typename internal::Function<F>::Result Result;
957
958 // Asserts at compile time that F returns void.
959 CompileAssertTypesEqual<void, Result>();
960
961 return Action<F>(new Impl<F>(action_));
962 }
963
964 private:
965 template <typename F>
966 class Impl : public ActionInterface<F> {
967 public:
968 typedef typename internal::Function<F>::Result Result;
969 typedef typename internal::Function<F>::ArgumentTuple ArgumentTuple;
970
971 explicit Impl(const A& action) : action_(action) {}
972
973 virtual void Perform(const ArgumentTuple& args) {
974 // Performs the action and ignores its result.
975 action_.Perform(args);
976 }
977
978 private:
979 // Type OriginalFunction is the same as F except that its return
980 // type is IgnoredValue.
981 typedef typename internal::Function<F>::MakeResultIgnoredValue
982 OriginalFunction;
983
984 const Action<OriginalFunction> action_;
985
986 GTEST_DISALLOW_ASSIGN_(Impl);
987 };
988
989 const A action_;
990
991 GTEST_DISALLOW_ASSIGN_(IgnoreResultAction);
992 };
993
994 // A ReferenceWrapper<T> object represents a reference to type T,
995 // which can be either const or not. It can be explicitly converted
996 // from, and implicitly converted to, a T&. Unlike a reference,
997 // ReferenceWrapper<T> can be copied and can survive template type
998 // inference. This is used to support by-reference arguments in the
999 // InvokeArgument<N>(...) action. The idea was from "reference
1000 // wrappers" in tr1, which we don't have in our source tree yet.
1001 template <typename T>
1002 class ReferenceWrapper {
1003 public:
1004 // Constructs a ReferenceWrapper<T> object from a T&.
1005 explicit ReferenceWrapper(T& l_value) : pointer_(&l_value) {} // NOLINT
1006
1007 // Allows a ReferenceWrapper<T> object to be implicitly converted to
1008 // a T&.
1009 operator T&() const { return *pointer_; }
1010 private:
1011 T* pointer_;
1012 };
1013
1014 // Allows the expression ByRef(x) to be printed as a reference to x.
1015 template <typename T>
1016 void PrintTo(const ReferenceWrapper<T>& ref, ::std::ostream* os) {
1017 T& value = ref;
1018 UniversalPrinter<T&>::Print(value, os);
1019 }
1020
1021 // Does two actions sequentially. Used for implementing the DoAll(a1,
1022 // a2, ...) action.
1023 template <typename Action1, typename Action2>
1024 class DoBothAction {
1025 public:
1026 DoBothAction(Action1 action1, Action2 action2)
1027 : action1_(action1), action2_(action2) {}
1028
1029 // This template type conversion operator allows DoAll(a1, ..., a_n)
1030 // to be used in ANY function of compatible type.
1031 template <typename F>
1032 operator Action<F>() const {
1033 return Action<F>(new Impl<F>(action1_, action2_));
1034 }
1035
1036 private:
1037 // Implements the DoAll(...) action for a particular function type F.
1038 template <typename F>
1039 class Impl : public ActionInterface<F> {
1040 public:
1041 typedef typename Function<F>::Result Result;
1042 typedef typename Function<F>::ArgumentTuple ArgumentTuple;
1043 typedef typename Function<F>::MakeResultVoid VoidResult;
1044
1045 Impl(const Action<VoidResult>& action1, const Action<F>& action2)
1046 : action1_(action1), action2_(action2) {}
1047
1048 virtual Result Perform(const ArgumentTuple& args) {
1049 action1_.Perform(args);
1050 return action2_.Perform(args);
1051 }
1052
1053 private:
1054 const Action<VoidResult> action1_;
1055 const Action<F> action2_;
1056
1057 GTEST_DISALLOW_ASSIGN_(Impl);
1058 };
1059
1060 Action1 action1_;
1061 Action2 action2_;
1062
1063 GTEST_DISALLOW_ASSIGN_(DoBothAction);
1064 };
1065
1066 } // namespace internal
1067
1068 // An Unused object can be implicitly constructed from ANY value.
1069 // This is handy when defining actions that ignore some or all of the
1070 // mock function arguments. For example, given
1071 //
1072 // MOCK_METHOD3(Foo, double(const string& label, double x, double y));
1073 // MOCK_METHOD3(Bar, double(int index, double x, double y));
1074 //
1075 // instead of
1076 //
1077 // double DistanceToOriginWithLabel(const string& label, double x, double y) {
1078 // return sqrt(x*x + y*y);
1079 // }
1080 // double DistanceToOriginWithIndex(int index, double x, double y) {
1081 // return sqrt(x*x + y*y);
1082 // }
1083 // ...
1084 // EXPECT_CALL(mock, Foo("abc", _, _))
1085 // .WillOnce(Invoke(DistanceToOriginWithLabel));
1086 // EXPECT_CALL(mock, Bar(5, _, _))
1087 // .WillOnce(Invoke(DistanceToOriginWithIndex));
1088 //
1089 // you could write
1090 //
1091 // // We can declare any uninteresting argument as Unused.
1092 // double DistanceToOrigin(Unused, double x, double y) {
1093 // return sqrt(x*x + y*y);
1094 // }
1095 // ...
1096 // EXPECT_CALL(mock, Foo("abc", _, _)).WillOnce(Invoke(DistanceToOrigin));
1097 // EXPECT_CALL(mock, Bar(5, _, _)).WillOnce(Invoke(DistanceToOrigin));
1098 typedef internal::IgnoredValue Unused;
1099
1100 // This constructor allows us to turn an Action<From> object into an
1101 // Action<To>, as long as To's arguments can be implicitly converted
1102 // to From's and From's return type cann be implicitly converted to
1103 // To's.
1104 template <typename To>
1105 template <typename From>
1106 Action<To>::Action(const Action<From>& from)
1107 :
1108 #if GTEST_LANG_CXX11
1109 fun_(from.fun_),
1110 #endif
1111 impl_(from.impl_ == NULL ? NULL
1112 : new internal::ActionAdaptor<To, From>(from)) {
1113 }
1114
1115 // Creates an action that returns 'value'. 'value' is passed by value
1116 // instead of const reference - otherwise Return("string literal")
1117 // will trigger a compiler error about using array as initializer.
1118 template <typename R>
1119 internal::ReturnAction<R> Return(R value) {
1120 return internal::ReturnAction<R>(internal::move(value));
1121 }
1122
1123 // Creates an action that returns NULL.
1124 inline PolymorphicAction<internal::ReturnNullAction> ReturnNull() {
1125 return MakePolymorphicAction(internal::ReturnNullAction());
1126 }
1127
1128 // Creates an action that returns from a void function.
1129 inline PolymorphicAction<internal::ReturnVoidAction> Return() {
1130 return MakePolymorphicAction(internal::ReturnVoidAction());
1131 }
1132
1133 // Creates an action that returns the reference to a variable.
1134 template <typename R>
1135 inline internal::ReturnRefAction<R> ReturnRef(R& x) { // NOLINT
1136 return internal::ReturnRefAction<R>(x);
1137 }
1138
1139 // Creates an action that returns the reference to a copy of the
1140 // argument. The copy is created when the action is constructed and
1141 // lives as long as the action.
1142 template <typename R>
1143 inline internal::ReturnRefOfCopyAction<R> ReturnRefOfCopy(const R& x) {
1144 return internal::ReturnRefOfCopyAction<R>(x);
1145 }
1146
1147 // Modifies the parent action (a Return() action) to perform a move of the
1148 // argument instead of a copy.
1149 // Return(ByMove()) actions can only be executed once and will assert this
1150 // invariant.
1151 template <typename R>
1152 internal::ByMoveWrapper<R> ByMove(R x) {
1153 return internal::ByMoveWrapper<R>(internal::move(x));
1154 }
1155
1156 // Creates an action that does the default action for the give mock function.
1157 inline internal::DoDefaultAction DoDefault() {
1158 return internal::DoDefaultAction();
1159 }
1160
1161 // Creates an action that sets the variable pointed by the N-th
1162 // (0-based) function argument to 'value'.
1163 template <size_t N, typename T>
1164 PolymorphicAction<
1165 internal::SetArgumentPointeeAction<
1166 N, T, internal::IsAProtocolMessage<T>::value> >
1167 SetArgPointee(const T& x) {
1168 return MakePolymorphicAction(internal::SetArgumentPointeeAction<
1169 N, T, internal::IsAProtocolMessage<T>::value>(x));
1170 }
1171
1172 #if !((GTEST_GCC_VER_ && GTEST_GCC_VER_ < 40000) || GTEST_OS_SYMBIAN)
1173 // This overload allows SetArgPointee() to accept a string literal.
1174 // GCC prior to the version 4.0 and Symbian C++ compiler cannot distinguish
1175 // this overload from the templated version and emit a compile error.
1176 template <size_t N>
1177 PolymorphicAction<
1178 internal::SetArgumentPointeeAction<N, const char*, false> >
1179 SetArgPointee(const char* p) {
1180 return MakePolymorphicAction(internal::SetArgumentPointeeAction<
1181 N, const char*, false>(p));
1182 }
1183
1184 template <size_t N>
1185 PolymorphicAction<
1186 internal::SetArgumentPointeeAction<N, const wchar_t*, false> >
1187 SetArgPointee(const wchar_t* p) {
1188 return MakePolymorphicAction(internal::SetArgumentPointeeAction<
1189 N, const wchar_t*, false>(p));
1190 }
1191 #endif
1192
1193 // The following version is DEPRECATED.
1194 template <size_t N, typename T>
1195 PolymorphicAction<
1196 internal::SetArgumentPointeeAction<
1197 N, T, internal::IsAProtocolMessage<T>::value> >
1198 SetArgumentPointee(const T& x) {
1199 return MakePolymorphicAction(internal::SetArgumentPointeeAction<
1200 N, T, internal::IsAProtocolMessage<T>::value>(x));
1201 }
1202
1203 // Creates an action that sets a pointer referent to a given value.
1204 template <typename T1, typename T2>
1205 PolymorphicAction<internal::AssignAction<T1, T2> > Assign(T1* ptr, T2 val) {
1206 return MakePolymorphicAction(internal::AssignAction<T1, T2>(ptr, val));
1207 }
1208
1209 #if !GTEST_OS_WINDOWS_MOBILE
1210
1211 // Creates an action that sets errno and returns the appropriate error.
1212 template <typename T>
1213 PolymorphicAction<internal::SetErrnoAndReturnAction<T> >
1214 SetErrnoAndReturn(int errval, T result) {
1215 return MakePolymorphicAction(
1216 internal::SetErrnoAndReturnAction<T>(errval, result));
1217 }
1218
1219 #endif // !GTEST_OS_WINDOWS_MOBILE
1220
1221 // Various overloads for InvokeWithoutArgs().
1222
1223 // Creates an action that invokes 'function_impl' with no argument.
1224 template <typename FunctionImpl>
1225 PolymorphicAction<internal::InvokeWithoutArgsAction<FunctionImpl> >
1226 InvokeWithoutArgs(FunctionImpl function_impl) {
1227 return MakePolymorphicAction(
1228 internal::InvokeWithoutArgsAction<FunctionImpl>(function_impl));
1229 }
1230
1231 // Creates an action that invokes the given method on the given object
1232 // with no argument.
1233 template <class Class, typename MethodPtr>
1234 PolymorphicAction<internal::InvokeMethodWithoutArgsAction<Class, MethodPtr> >
1235 InvokeWithoutArgs(Class* obj_ptr, MethodPtr method_ptr) {
1236 return MakePolymorphicAction(
1237 internal::InvokeMethodWithoutArgsAction<Class, MethodPtr>(
1238 obj_ptr, method_ptr));
1239 }
1240
1241 // Creates an action that performs an_action and throws away its
1242 // result. In other words, it changes the return type of an_action to
1243 // void. an_action MUST NOT return void, or the code won't compile.
1244 template <typename A>
1245 inline internal::IgnoreResultAction<A> IgnoreResult(const A& an_action) {
1246 return internal::IgnoreResultAction<A>(an_action);
1247 }
1248
1249 // Creates a reference wrapper for the given L-value. If necessary,
1250 // you can explicitly specify the type of the reference. For example,
1251 // suppose 'derived' is an object of type Derived, ByRef(derived)
1252 // would wrap a Derived&. If you want to wrap a const Base& instead,
1253 // where Base is a base class of Derived, just write:
1254 //
1255 // ByRef<const Base>(derived)
1256 template <typename T>
1257 inline internal::ReferenceWrapper<T> ByRef(T& l_value) { // NOLINT
1258 return internal::ReferenceWrapper<T>(l_value);
1259 }
1260
1261 } // namespace testing
1262
1263 #endif // GMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_