• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 //===---------- llvm/unittest/Support/Casting.cpp - Casting tests ---------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm/Support/Casting.h"
11 #include "llvm/IR/User.h"
12 #include "llvm/Support/Debug.h"
13 #include "llvm/Support/raw_ostream.h"
14 #include "gtest/gtest.h"
15 #include <cstdlib>
16 
17 namespace llvm {
18 // Used to test illegal cast. If a cast doesn't match any of the "real" ones,
19 // it will match this one.
20 struct IllegalCast;
cast(...)21 template <typename T> IllegalCast *cast(...) { return nullptr; }
22 
23 // set up two example classes
24 // with conversion facility
25 //
26 struct bar {
barllvm::bar27   bar() {}
28   struct foo *baz();
29   struct foo *caz();
30   struct foo *daz();
31   struct foo *naz();
32 private:
33   bar(const bar &);
34 };
35 struct foo {
36   void ext() const;
37   /*  static bool classof(const bar *X) {
38     cerr << "Classof: " << X << "\n";
39     return true;
40     }*/
41 };
42 
43 struct base {
~basellvm::base44   virtual ~base() {}
45 };
46 
47 struct derived : public base {
classofllvm::derived48   static bool classof(const base *B) { return true; }
49 };
50 
51 template <> struct isa_impl<foo, bar> {
doitllvm::isa_impl52   static inline bool doit(const bar &Val) {
53     dbgs() << "Classof: " << &Val << "\n";
54     return true;
55   }
56 };
57 
58 template <typename T> struct isa_impl<foo, T> {
doitllvm::isa_impl59   static inline bool doit(const T &Val) { return false; }
60 };
61 
baz()62 foo *bar::baz() {
63     return cast<foo>(this);
64 }
65 
caz()66 foo *bar::caz() {
67     return cast_or_null<foo>(this);
68 }
69 
daz()70 foo *bar::daz() {
71     return dyn_cast<foo>(this);
72 }
73 
naz()74 foo *bar::naz() {
75     return dyn_cast_or_null<foo>(this);
76 }
77 
78 
79 bar *fub();
80 
81 template <> struct simplify_type<foo> {
82   typedef int SimpleType;
getSimplifiedValuellvm::simplify_type83   static SimpleType getSimplifiedValue(foo &Val) { return 0; }
84 };
85 
86 } // End llvm namespace
87 
88 using namespace llvm;
89 
90 
91 // Test the peculiar behavior of Use in simplify_type.
92 static_assert(std::is_same<simplify_type<Use>::SimpleType, Value *>::value,
93               "Use doesn't simplify correctly!");
94 static_assert(std::is_same<simplify_type<Use *>::SimpleType, Value *>::value,
95               "Use doesn't simplify correctly!");
96 
97 // Test that a regular class behaves as expected.
98 static_assert(std::is_same<simplify_type<foo>::SimpleType, int>::value,
99               "Unexpected simplify_type result!");
100 static_assert(std::is_same<simplify_type<foo *>::SimpleType, foo *>::value,
101               "Unexpected simplify_type result!");
102 
103 namespace {
104 
105 const foo *null_foo = nullptr;
106 
107 bar B;
108 extern bar &B1;
109 bar &B1 = B;
110 extern const bar *B2;
111 // test various configurations of const
112 const bar &B3 = B1;
113 const bar *const B4 = B2;
114 
TEST(CastingTest,isa)115 TEST(CastingTest, isa) {
116   EXPECT_TRUE(isa<foo>(B1));
117   EXPECT_TRUE(isa<foo>(B2));
118   EXPECT_TRUE(isa<foo>(B3));
119   EXPECT_TRUE(isa<foo>(B4));
120 }
121 
TEST(CastingTest,cast)122 TEST(CastingTest, cast) {
123   foo &F1 = cast<foo>(B1);
124   EXPECT_NE(&F1, null_foo);
125   const foo *F3 = cast<foo>(B2);
126   EXPECT_NE(F3, null_foo);
127   const foo *F4 = cast<foo>(B2);
128   EXPECT_NE(F4, null_foo);
129   const foo &F5 = cast<foo>(B3);
130   EXPECT_NE(&F5, null_foo);
131   const foo *F6 = cast<foo>(B4);
132   EXPECT_NE(F6, null_foo);
133   // Can't pass null pointer to cast<>.
134   // foo *F7 = cast<foo>(fub());
135   // EXPECT_EQ(F7, null_foo);
136   foo *F8 = B1.baz();
137   EXPECT_NE(F8, null_foo);
138 
139   std::unique_ptr<const bar> BP(B2);
140   auto FP = cast<foo>(std::move(BP));
141   static_assert(std::is_same<std::unique_ptr<const foo>, decltype(FP)>::value,
142                 "Incorrect deduced return type!");
143   EXPECT_NE(FP.get(), null_foo);
144   FP.release();
145 }
146 
TEST(CastingTest,cast_or_null)147 TEST(CastingTest, cast_or_null) {
148   const foo *F11 = cast_or_null<foo>(B2);
149   EXPECT_NE(F11, null_foo);
150   const foo *F12 = cast_or_null<foo>(B2);
151   EXPECT_NE(F12, null_foo);
152   const foo *F13 = cast_or_null<foo>(B4);
153   EXPECT_NE(F13, null_foo);
154   const foo *F14 = cast_or_null<foo>(fub());  // Shouldn't print.
155   EXPECT_EQ(F14, null_foo);
156   foo *F15 = B1.caz();
157   EXPECT_NE(F15, null_foo);
158 
159   std::unique_ptr<const bar> BP(fub());
160   auto FP = cast_or_null<foo>(std::move(BP));
161   EXPECT_EQ(FP.get(), null_foo);
162 }
163 
TEST(CastingTest,dyn_cast)164 TEST(CastingTest, dyn_cast) {
165   const foo *F1 = dyn_cast<foo>(B2);
166   EXPECT_NE(F1, null_foo);
167   const foo *F2 = dyn_cast<foo>(B2);
168   EXPECT_NE(F2, null_foo);
169   const foo *F3 = dyn_cast<foo>(B4);
170   EXPECT_NE(F3, null_foo);
171   // Can't pass null pointer to dyn_cast<>.
172   // foo *F4 = dyn_cast<foo>(fub());
173   // EXPECT_EQ(F4, null_foo);
174   foo *F5 = B1.daz();
175   EXPECT_NE(F5, null_foo);
176 }
177 
TEST(CastingTest,dyn_cast_or_null)178 TEST(CastingTest, dyn_cast_or_null) {
179   const foo *F1 = dyn_cast_or_null<foo>(B2);
180   EXPECT_NE(F1, null_foo);
181   const foo *F2 = dyn_cast_or_null<foo>(B2);
182   EXPECT_NE(F2, null_foo);
183   const foo *F3 = dyn_cast_or_null<foo>(B4);
184   EXPECT_NE(F3, null_foo);
185   foo *F4 = dyn_cast_or_null<foo>(fub());
186   EXPECT_EQ(F4, null_foo);
187   foo *F5 = B1.naz();
188   EXPECT_NE(F5, null_foo);
189 }
190 
newd()191 std::unique_ptr<derived> newd() { return llvm::make_unique<derived>(); }
newb()192 std::unique_ptr<base> newb() { return llvm::make_unique<derived>(); }
193 
TEST(CastingTest,unique_dyn_cast)194 TEST(CastingTest, unique_dyn_cast) {
195   derived *OrigD = nullptr;
196   auto D = llvm::make_unique<derived>();
197   OrigD = D.get();
198 
199   // Converting from D to itself is valid, it should return a new unique_ptr
200   // and the old one should become nullptr.
201   auto NewD = unique_dyn_cast<derived>(D);
202   ASSERT_EQ(OrigD, NewD.get());
203   ASSERT_EQ(nullptr, D);
204 
205   // Converting from D to B is valid, B should have a value and D should be
206   // nullptr.
207   auto B = unique_dyn_cast<base>(NewD);
208   ASSERT_EQ(OrigD, B.get());
209   ASSERT_EQ(nullptr, NewD);
210 
211   // Converting from B to itself is valid, it should return a new unique_ptr
212   // and the old one should become nullptr.
213   auto NewB = unique_dyn_cast<base>(B);
214   ASSERT_EQ(OrigD, NewB.get());
215   ASSERT_EQ(nullptr, B);
216 
217   // Converting from B to D is valid, D should have a value and B should be
218   // nullptr;
219   D = unique_dyn_cast<derived>(NewB);
220   ASSERT_EQ(OrigD, D.get());
221   ASSERT_EQ(nullptr, NewB);
222 
223   // Converting between unrelated types should fail.  The original value should
224   // remain unchanged and it should return nullptr.
225   auto F = unique_dyn_cast<foo>(D);
226   ASSERT_EQ(nullptr, F);
227   ASSERT_EQ(OrigD, D.get());
228 
229   // All of the above should also hold for temporaries.
230   auto D2 = unique_dyn_cast<derived>(newd());
231   EXPECT_NE(nullptr, D2);
232 
233   auto B2 = unique_dyn_cast<derived>(newb());
234   EXPECT_NE(nullptr, B2);
235 
236   auto B3 = unique_dyn_cast<base>(newb());
237   EXPECT_NE(nullptr, B3);
238 
239   auto F2 = unique_dyn_cast<foo>(newb());
240   EXPECT_EQ(nullptr, F2);
241 }
242 
243 // These lines are errors...
244 //foo *F20 = cast<foo>(B2);  // Yields const foo*
245 //foo &F21 = cast<foo>(B3);  // Yields const foo&
246 //foo *F22 = cast<foo>(B4);  // Yields const foo*
247 //foo &F23 = cast_or_null<foo>(B1);
248 //const foo &F24 = cast_or_null<foo>(B3);
249 
250 const bar *B2 = &B;
251 }  // anonymous namespace
252 
fub()253 bar *llvm::fub() { return nullptr; }
254 
255 namespace {
256 namespace inferred_upcasting {
257 // This test case verifies correct behavior of inferred upcasts when the
258 // types are statically known to be OK to upcast. This is the case when,
259 // for example, Derived inherits from Base, and we do `isa<Base>(Derived)`.
260 
261 // Note: This test will actually fail to compile without inferred
262 // upcasting.
263 
264 class Base {
265 public:
266   // No classof. We are testing that the upcast is inferred.
Base()267   Base() {}
268 };
269 
270 class Derived : public Base {
271 public:
Derived()272   Derived() {}
273 };
274 
275 // Even with no explicit classof() in Base, we should still be able to cast
276 // Derived to its base class.
TEST(CastingTest,UpcastIsInferred)277 TEST(CastingTest, UpcastIsInferred) {
278   Derived D;
279   EXPECT_TRUE(isa<Base>(D));
280   Base *BP = dyn_cast<Base>(&D);
281   EXPECT_TRUE(BP != nullptr);
282 }
283 
284 
285 // This test verifies that the inferred upcast takes precedence over an
286 // explicitly written one. This is important because it verifies that the
287 // dynamic check gets optimized away.
288 class UseInferredUpcast {
289 public:
290   int Dummy;
classof(const UseInferredUpcast *)291   static bool classof(const UseInferredUpcast *) {
292     return false;
293   }
294 };
295 
TEST(CastingTest,InferredUpcastTakesPrecedence)296 TEST(CastingTest, InferredUpcastTakesPrecedence) {
297   UseInferredUpcast UIU;
298   // Since the explicit classof() returns false, this will fail if the
299   // explicit one is used.
300   EXPECT_TRUE(isa<UseInferredUpcast>(&UIU));
301 }
302 
303 } // end namespace inferred_upcasting
304 } // end anonymous namespace
305 // Test that we reject casts of temporaries (and so the illegal cast gets used).
306 namespace TemporaryCast {
307 struct pod {};
testIllegalCast()308 IllegalCast *testIllegalCast() { return cast<foo>(pod()); }
309 }
310 
311 namespace {
312 namespace pointer_wrappers {
313 
314 struct Base {
315   bool IsDerived;
Base__anonfc5f95040311::pointer_wrappers::Base316   Base(bool IsDerived = false) : IsDerived(IsDerived) {}
317 };
318 
319 struct Derived : Base {
Derived__anonfc5f95040311::pointer_wrappers::Derived320   Derived() : Base(true) {}
classof__anonfc5f95040311::pointer_wrappers::Derived321   static bool classof(const Base *B) { return B->IsDerived; }
322 };
323 
324 class PTy {
325   Base *B;
326 public:
PTy(Base * B)327   PTy(Base *B) : B(B) {}
operator bool() const328   explicit operator bool() const { return get(); }
get() const329   Base *get() const { return B; }
330 };
331 
332 } // end namespace pointer_wrappers
333 } // end namespace
334 
335 namespace llvm {
336 
337 template <> struct simplify_type<pointer_wrappers::PTy> {
338   typedef pointer_wrappers::Base *SimpleType;
getSimplifiedValuellvm::simplify_type339   static SimpleType getSimplifiedValue(pointer_wrappers::PTy &P) {
340     return P.get();
341   }
342 };
343 template <> struct simplify_type<const pointer_wrappers::PTy> {
344   typedef pointer_wrappers::Base *SimpleType;
getSimplifiedValuellvm::simplify_type345   static SimpleType getSimplifiedValue(const pointer_wrappers::PTy &P) {
346     return P.get();
347   }
348 };
349 
350 } // end namespace llvm
351 
352 namespace {
353 namespace pointer_wrappers {
354 
355 // Some objects.
356 pointer_wrappers::Base B;
357 pointer_wrappers::Derived D;
358 
359 // Mutable "smart" pointers.
360 pointer_wrappers::PTy MN(nullptr);
361 pointer_wrappers::PTy MB(&B);
362 pointer_wrappers::PTy MD(&D);
363 
364 // Const "smart" pointers.
365 const pointer_wrappers::PTy CN(nullptr);
366 const pointer_wrappers::PTy CB(&B);
367 const pointer_wrappers::PTy CD(&D);
368 
TEST(CastingTest,smart_isa)369 TEST(CastingTest, smart_isa) {
370   EXPECT_TRUE(!isa<pointer_wrappers::Derived>(MB));
371   EXPECT_TRUE(!isa<pointer_wrappers::Derived>(CB));
372   EXPECT_TRUE(isa<pointer_wrappers::Derived>(MD));
373   EXPECT_TRUE(isa<pointer_wrappers::Derived>(CD));
374 }
375 
TEST(CastingTest,smart_cast)376 TEST(CastingTest, smart_cast) {
377   EXPECT_TRUE(cast<pointer_wrappers::Derived>(MD) == &D);
378   EXPECT_TRUE(cast<pointer_wrappers::Derived>(CD) == &D);
379 }
380 
TEST(CastingTest,smart_cast_or_null)381 TEST(CastingTest, smart_cast_or_null) {
382   EXPECT_TRUE(cast_or_null<pointer_wrappers::Derived>(MN) == nullptr);
383   EXPECT_TRUE(cast_or_null<pointer_wrappers::Derived>(CN) == nullptr);
384   EXPECT_TRUE(cast_or_null<pointer_wrappers::Derived>(MD) == &D);
385   EXPECT_TRUE(cast_or_null<pointer_wrappers::Derived>(CD) == &D);
386 }
387 
TEST(CastingTest,smart_dyn_cast)388 TEST(CastingTest, smart_dyn_cast) {
389   EXPECT_TRUE(dyn_cast<pointer_wrappers::Derived>(MB) == nullptr);
390   EXPECT_TRUE(dyn_cast<pointer_wrappers::Derived>(CB) == nullptr);
391   EXPECT_TRUE(dyn_cast<pointer_wrappers::Derived>(MD) == &D);
392   EXPECT_TRUE(dyn_cast<pointer_wrappers::Derived>(CD) == &D);
393 }
394 
TEST(CastingTest,smart_dyn_cast_or_null)395 TEST(CastingTest, smart_dyn_cast_or_null) {
396   EXPECT_TRUE(dyn_cast_or_null<pointer_wrappers::Derived>(MN) == nullptr);
397   EXPECT_TRUE(dyn_cast_or_null<pointer_wrappers::Derived>(CN) == nullptr);
398   EXPECT_TRUE(dyn_cast_or_null<pointer_wrappers::Derived>(MB) == nullptr);
399   EXPECT_TRUE(dyn_cast_or_null<pointer_wrappers::Derived>(CB) == nullptr);
400   EXPECT_TRUE(dyn_cast_or_null<pointer_wrappers::Derived>(MD) == &D);
401   EXPECT_TRUE(dyn_cast_or_null<pointer_wrappers::Derived>(CD) == &D);
402 }
403 
404 } // end namespace pointer_wrappers
405 } // end namespace
406