testing/generate_gmock_mutant.py

   1 #!/usr/bin/env python
   2 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
   3 # Use of this source code is governed by a BSD-style license that can be
   4 # found in the LICENSE file.
   5
   6 import string
   7 import sys
   8
   9 HEADER = """\
  10 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
  11 // Use of this source code is governed by a BSD-style license that can be
  12 // found in the LICENSE file.
  13
  14 // This file automatically generated by testing/generate_gmock_mutant.py.
  15 // DO NOT EDIT.
  16
  17 #ifndef TESTING_GMOCK_MUTANT_H_
  18 #define TESTING_GMOCK_MUTANT_H_
  19
  20 // The intention of this file is to make possible using GMock actions in
  21 // all of its syntactic beauty. Classes and helper functions can be used as
  22 // more generic variants of Task and Callback classes (see base/task.h)
  23 // Mutant supports both pre-bound arguments (like Task) and call-time
  24 // arguments (like Callback) - hence the name. :-)
  25 //
  26 // DispatchToMethod/Function supports two sets of arguments: pre-bound (P) and
  27 // call-time (C). The arguments as well as the return type are templatized.
  28 // DispatchToMethod/Function will also try to call the selected method or
  29 // function even if provided pre-bound arguments does not match exactly with
  30 // the function signature hence the X1, X2 ... XN parameters in CreateFunctor.
  31 // DispatchToMethod will try to invoke method that may not belong to the
  32 // object's class itself but to the object's class base class.
  33 //
  34 // Additionally you can bind the object at calltime by binding a pointer to
  35 // pointer to the object at creation time - before including this file you
  36 // have to #define GMOCK_MUTANT_INCLUDE_LATE_OBJECT_BINDING.
  37 //
  38 // TODO(stoyan): It's yet not clear to me should we use T& and T&* instead
  39 // of T* and T** when we invoke CreateFunctor to match the EXPECT_CALL style.
  40 //
  41 //
  42 // Sample usage with gMock:
  43 //
  44 // struct Mock : public ObjectDelegate {
  45 //   MOCK_METHOD2(string, OnRequest(int n, const string& request));
  46 //   MOCK_METHOD1(void, OnQuit(int exit_code));
  47 //   MOCK_METHOD2(void, LogMessage(int level, const string& message));
  48 //
  49 //   string HandleFlowers(const string& reply, int n, const string& request) {
  50 //     string result = SStringPrintf("In request of %d %s ", n, request);
  51 //     for (int i = 0; i < n; ++i) result.append(reply)
  52 //     return result;
  53 //   }
  54 //
  55 //   void DoLogMessage(int level, const string& message) {
  56 //   }
  57 //
  58 //   void QuitMessageLoop(int seconds) {
  59 //     base::MessageLoop* loop = base::MessageLoop::current();
  60 //     loop->PostDelayedTask(FROM_HERE, base::MessageLoop::QuitClosure(),
  61 //                           1000 * seconds);
  62 //   }
  63 // };
  64 //
  65 // Mock mock;
  66 // // Will invoke mock.HandleFlowers("orchids", n, request)
  67 // // "orchids" is a pre-bound argument, and <n> and <request> are call-time
  68 // // arguments - they are not known until the OnRequest mock is invoked.
  69 // EXPECT_CALL(mock, OnRequest(Ge(5), StartsWith("flower"))
  70 //   .Times(1)
  71 //   .WillOnce(Invoke(CreateFunctor(&mock, &Mock::HandleFlowers,
  72 //       string("orchids"))));
  73 //
  74 //
  75 // // No pre-bound arguments, two call-time arguments passed
  76 // // directly to DoLogMessage
  77 // EXPECT_CALL(mock, OnLogMessage(_, _))
  78 //   .Times(AnyNumber())
  79 //   .WillAlways(Invoke(CreateFunctor, &mock, &Mock::DoLogMessage));
  80 //
  81 //
  82 // // In this case we have a single pre-bound argument - 3. We ignore
  83 // // all of the arguments of OnQuit.
  84 // EXCEPT_CALL(mock, OnQuit(_))
  85 //   .Times(1)
  86 //   .WillOnce(InvokeWithoutArgs(CreateFunctor(
  87 //       &mock, &Mock::QuitMessageLoop, 3)));
  88 //
  89 // MessageLoop loop;
  90 // loop.Run();
  91 //
  92 //
  93 //  // Here is another example of how we can set an action that invokes
  94 //  // method of an object that is not yet created.
  95 // struct Mock : public ObjectDelegate {
  96 //   MOCK_METHOD1(void, DemiurgeCreated(Demiurge*));
  97 //   MOCK_METHOD2(void, OnRequest(int count, const string&));
  98 //
  99 //   void StoreDemiurge(Demiurge* w) {
 100 //     demiurge_ = w;
 101 //   }
 102 //
 103 //   Demiurge* demiurge;
 104 // }
 105 //
 106 // EXPECT_CALL(mock, DemiurgeCreated(_)).Times(1)
 107 //    .WillOnce(Invoke(CreateFunctor(&mock, &Mock::StoreDemiurge)));
 108 //
 109 // EXPECT_CALL(mock, OnRequest(_, StrEq("Moby Dick")))
 110 //    .Times(AnyNumber())
 111 //    .WillAlways(WithArgs<0>(Invoke(
 112 //        CreateFunctor(&mock->demiurge_, &Demiurge::DecreaseMonsters))));
 113 //
 114
 115 #include "base/memory/linked_ptr.h"
 116 #include "base/tuple.h"  // for Tuple
 117
 118 namespace testing {"""
 119
 120 MUTANT = """\
 121
 122 // Interface that is exposed to the consumer, that does the actual calling
 123 // of the method.
 124 template <typename R, typename Params>
 125 class MutantRunner {
 126  public:
 127   virtual R RunWithParams(const Params& params) = 0;
 128   virtual ~MutantRunner() {}
 129 };
 130
 131 // Mutant holds pre-bound arguments (like Task). Like Callback
 132 // allows call-time arguments. You bind a pointer to the object
 133 // at creation time.
 134 template <typename R, typename T, typename Method,
 135           typename PreBound, typename Params>
 136 class Mutant : public MutantRunner<R, Params> {
 137  public:
 138   Mutant(T* obj, Method method, const PreBound& pb)
 139       : obj_(obj), method_(method), pb_(pb) {
 140   }
 141
 142   // MutantRunner implementation
 143   virtual R RunWithParams(const Params& params) {
 144     return DispatchToMethod<R>(this->obj_, this->method_, pb_, params);
 145   }
 146
 147   T* obj_;
 148   Method method_;
 149   PreBound pb_;
 150 };
 151
 152 template <typename R, typename Function, typename PreBound, typename Params>
 153 class MutantFunction : public MutantRunner<R, Params> {
 154  public:
 155   MutantFunction(Function function, const PreBound& pb)
 156       : function_(function), pb_(pb) {
 157   }
 158
 159   // MutantRunner implementation
 160   virtual R RunWithParams(const Params& params) {
 161     return DispatchToFunction<R>(function_, pb_, params);
 162   }
 163
 164   Function function_;
 165   PreBound pb_;
 166 };
 167
 168 #ifdef GMOCK_MUTANT_INCLUDE_LATE_OBJECT_BINDING
 169 // MutantLateBind is like Mutant, but you bind a pointer to a pointer
 170 // to the object. This way you can create actions for an object
 171 // that is not yet created (has only storage for a pointer to it).
 172 template <typename R, typename T, typename Method,
 173           typename PreBound, typename Params>
 174 class MutantLateObjectBind : public MutantRunner<R, Params> {
 175  public:
 176   MutantLateObjectBind(T** obj, Method method, const PreBound& pb)
 177       : obj_(obj), method_(method), pb_(pb) {
 178   }
 179
 180   // MutantRunner implementation.
 181   virtual R RunWithParams(const Params& params) {
 182     EXPECT_THAT(*this->obj_, testing::NotNull());
 183     if (NULL == *this->obj_)
 184       return R();
 185     return DispatchToMethod<R>( *this->obj_, this->method_, pb_, params);
 186   }
 187
 188   T** obj_;
 189   Method method_;
 190   PreBound pb_;
 191 };
 192 #endif
 193
 194 // Simple MutantRunner<> wrapper acting as a functor.
 195 // Redirects operator() to MutantRunner<Params>::Run()
 196 template <typename R, typename Params>
 197 struct MutantFunctor {
 198   explicit MutantFunctor(MutantRunner<R, Params>*  cb) : impl_(cb) {
 199   }
 200
 201   ~MutantFunctor() {
 202   }
 203
 204   inline R operator()() {
 205     return impl_->RunWithParams(Tuple<>());
 206   }
 207
 208   template <typename Arg1>
 209   inline R operator()(const Arg1& a) {
 210     return impl_->RunWithParams(Params(a));
 211   }
 212
 213   template <typename Arg1, typename Arg2>
 214   inline R operator()(const Arg1& a, const Arg2& b) {
 215     return impl_->RunWithParams(Params(a, b));
 216   }
 217
 218   template <typename Arg1, typename Arg2, typename Arg3>
 219   inline R operator()(const Arg1& a, const Arg2& b, const Arg3& c) {
 220     return impl_->RunWithParams(Params(a, b, c));
 221   }
 222
 223   template <typename Arg1, typename Arg2, typename Arg3, typename Arg4>
 224   inline R operator()(const Arg1& a, const Arg2& b, const Arg3& c,
 225                          const Arg4& d) {
 226     return impl_->RunWithParams(Params(a, b, c, d));
 227   }
 228
 229  private:
 230   // We need copy constructor since MutantFunctor is copied few times
 231   // inside GMock machinery, hence no DISALLOW_EVIL_CONTRUCTORS
 232   MutantFunctor();
 233   linked_ptr<MutantRunner<R, Params> > impl_;
 234 };
 235 """
 236
 237 FOOTER = """\
 238 }  // namespace testing
 239
 240 #endif  // TESTING_GMOCK_MUTANT_H_"""
 241
 242 # Templates for DispatchToMethod/DispatchToFunction functions.
 243 # template_params - typename P1, typename P2.. typename C1..
 244 # prebound - Tuple<P1, .. PN>
 245 # calltime - Tuple<C1, .. CN>
 246 # args - p.a, p.b.., c.a, c.b..
 247 DISPATCH_TO_METHOD_TEMPLATE = """\
 248 template <typename R, typename T, typename Method, %(template_params)s>
 249 inline R DispatchToMethod(T* obj, Method method,
 250                           const %(prebound)s& p,
 251                           const %(calltime)s& c) {
 252   return (obj->*method)(%(args)s);
 253 }
 254 """
 255
 256 DISPATCH_TO_FUNCTION_TEMPLATE = """\
 257 template <typename R, typename Function, %(template_params)s>
 258 inline R DispatchToFunction(Function function,
 259                             const %(prebound)s& p,
 260                             const %(calltime)s& c) {
 261   return (*function)(%(args)s);
 262 }
 263 """
 264
 265 # Templates for CreateFunctor functions.
 266 # template_params - typename P1, typename P2.. typename C1.. typename X1..
 267 # prebound - Tuple<P1, .. PN>
 268 # calltime - Tuple<A1, .. AN>
 269 # params - X1,.. , A1, ..
 270 # args - const P1& p1 ..
 271 # call_args - p1, p2, p3..
 272 CREATE_METHOD_FUNCTOR_TEMPLATE = """\
 273 template <typename R, typename T, typename U, %(template_params)s>
 274 inline MutantFunctor<R, %(calltime)s>
 275 CreateFunctor(T* obj, R (U::*method)(%(params)s), %(args)s) {
 276   MutantRunner<R, %(calltime)s>* t =
 277       new Mutant<R, T, R (U::*)(%(params)s),
 278                  %(prebound)s, %(calltime)s>
 279           (obj, method, MakeTuple(%(call_args)s));
 280   return MutantFunctor<R, %(calltime)s>(t);
 281 }
 282 """
 283
 284 CREATE_FUNCTION_FUNCTOR_TEMPLATE = """\
 285 template <typename R, %(template_params)s>
 286 inline MutantFunctor<R, %(calltime)s>
 287 CreateFunctor(R (*function)(%(params)s), %(args)s) {
 288   MutantRunner<R, %(calltime)s>* t =
 289       new MutantFunction<R, R (*)(%(params)s),
 290                          %(prebound)s, %(calltime)s>
 291           (function, MakeTuple(%(call_args)s));
 292   return MutantFunctor<R, %(calltime)s>(t);
 293 }
 294 """
 295
 296 def SplitLine(line, width):
 297   """Splits a single line at comma, at most |width| characters long."""
 298   if len(line) < width:
 299     return (line, None)
 300   n = 1 + line[:width].rfind(",")
 301   if n == 0:  # If comma cannot be found give up and return the entire line.
 302     return (line, None)
 303   # Assume there is a space after the comma
 304   assert line[n] == " "
 305   return (line[:n], line[n + 1:])
 306
 307
 308 def Wrap(s, width, subsequent_offset):
 309   """Wraps a single line |s| at commas so every line is at most |width|
 310      characters long.
 311   """
 312   w = []
 313   spaces = " " * subsequent_offset
 314   while s:
 315     (f, s) = SplitLine(s, width)
 316     w.append(f)
 317     if s:
 318       s = spaces  + s
 319   return "\n".join(w)
 320
 321
 322 def Clean(s):
 323   """Cleans artifacts from generated C++ code.
 324
 325   Our simple string formatting/concatenation may introduce extra commas.
 326   """
 327   s = s.replace(", >", ">")
 328   s = s.replace(", )", ")")
 329   return s
 330
 331
 332 def ExpandPattern(pattern, it):
 333   """Return list of expanded pattern strings.
 334
 335   Each string is created by replacing all '%' in |pattern| with element of |it|.
 336   """
 337   return [pattern.replace("%", x) for x in it]
 338
 339
 340 def Gen(pattern, n, start):
 341   """Expands pattern replacing '%' with sequential integers starting with start.
 342
 343   Expanded patterns will be joined with comma separator.
 344   Gen("X%", 3, 1) will return "X1, X2, X3".
 345   """
 346   it = string.hexdigits[start:n + start]
 347   return ", ".join(ExpandPattern(pattern, it))
 348
 349
 350 def Merge(a):
 351   return ", ".join(filter(len, a))
 352
 353
 354 def GenTuple(pattern, n):
 355   return Clean("Tuple<%s>" % (Gen(pattern, n, 1)))
 356
 357
 358 def FixCode(s):
 359   lines = Clean(s).splitlines()
 360   # Wrap sometimes very long 1st and 3rd line at 80th column.
 361   lines[0] = Wrap(lines[0], 80, 10)
 362   lines[2] = Wrap(lines[2], 80, 4)
 363   return "\n".join(lines)
 364
 365
 366 def GenerateDispatch(prebound, calltime):
 367   print "\n// %d - %d" % (prebound, calltime)
 368   args = {
 369       "template_params": Merge([Gen("typename P%", prebound, 1),
 370                                 Gen("typename C%", calltime, 1)]),
 371       "prebound": GenTuple("P%", prebound),
 372       "calltime": GenTuple("C%", calltime),
 373       "args": Merge([Gen("get<%>(p)", prebound, 0),
 374                      Gen("get<%>(c)", calltime, 0)]),
 375   }
 376
 377   print FixCode(DISPATCH_TO_METHOD_TEMPLATE % args)
 378   print FixCode(DISPATCH_TO_FUNCTION_TEMPLATE % args)
 379
 380
 381 def GenerateCreateFunctor(prebound, calltime):
 382   print "// %d - %d" % (prebound, calltime)
 383   args = {
 384       "calltime": GenTuple("A%", calltime),
 385       "prebound": GenTuple("P%", prebound),
 386       "params": Merge([Gen("X%", prebound, 1), Gen("A%", calltime, 1)]),
 387       "args": Gen("const P%& p%", prebound, 1),
 388       "call_args": Gen("p%", prebound, 1),
 389       "template_params": Merge([Gen("typename P%", prebound, 1),
 390                                 Gen("typename A%", calltime, 1),
 391                                 Gen("typename X%", prebound, 1)])
 392   }
 393
 394   mutant = FixCode(CREATE_METHOD_FUNCTOR_TEMPLATE % args)
 395   print mutant
 396
 397   # Slightly different version for free function call.
 398   print "\n", FixCode(CREATE_FUNCTION_FUNCTOR_TEMPLATE % args)
 399
 400   # Functor with pointer to a pointer of the object.
 401   print "\n#ifdef GMOCK_MUTANT_INCLUDE_LATE_OBJECT_BINDING"
 402   mutant2 = mutant.replace("CreateFunctor(T* obj,", "CreateFunctor(T** obj,")
 403   mutant2 = mutant2.replace("new Mutant", "new MutantLateObjectBind")
 404   mutant2 = mutant2.replace(" " * 17 + "Tuple", " " * 31 + "Tuple")
 405   print mutant2
 406   print "#endif  // GMOCK_MUTANT_INCLUDE_LATE_OBJECT_BINDING\n"
 407
 408   # OS_WIN specific. Same functors but with stdcall calling conventions.
 409   # These are not for WIN64 (x86_64) because there is only one calling
 410   # convention in WIN64.
 411   # Functor for method with __stdcall calling conventions.
 412   print "#if defined (OS_WIN) && !defined (ARCH_CPU_X86_64)"
 413   stdcall_method = CREATE_METHOD_FUNCTOR_TEMPLATE
 414   stdcall_method = stdcall_method.replace("U::", "__stdcall U::")
 415   stdcall_method = FixCode(stdcall_method % args)
 416   print stdcall_method
 417   # Functor for free function with __stdcall calling conventions.
 418   stdcall_function = CREATE_FUNCTION_FUNCTOR_TEMPLATE
 419   stdcall_function = stdcall_function.replace("R (*", "R (__stdcall *")
 420   print "\n", FixCode(stdcall_function % args)
 421
 422   print "#ifdef GMOCK_MUTANT_INCLUDE_LATE_OBJECT_BINDING"
 423   stdcall2 = stdcall_method
 424   stdcall2 = stdcall2.replace("CreateFunctor(T* obj,", "CreateFunctor(T** obj,")
 425   stdcall2 = stdcall2.replace("new Mutant", "new MutantLateObjectBind")
 426   stdcall2 = stdcall2.replace(" " * 17 + "Tuple", " " * 31 + "Tuple")
 427   print stdcall2
 428   print "#endif  // GMOCK_MUTANT_INCLUDE_LATE_OBJECT_BINDING"
 429   print "#endif  // defined (OS_WIN) && !defined (ARCH_CPU_X86_64)\n"
 430
 431
 432 def main():
 433   print HEADER
 434   for prebound in xrange(0, 6 + 1):
 435     for args in xrange(0, 6 + 1):
 436       GenerateDispatch(prebound, args)
 437   print MUTANT
 438   for prebound in xrange(0, 6 + 1):
 439     for args in xrange(0, 6 + 1):
 440       GenerateCreateFunctor(prebound, args)
 441   print FOOTER
 442   return 0
 443
 444
 445 if __name__ == "__main__":
 446   sys.exit(main())