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/Support/Debug.h"
12#include "llvm/Support/raw_ostream.h"
13#include "llvm/IR/User.h"
14#include "gtest/gtest.h"
15#include <cstdlib>
16
17namespace llvm {
18// Used to test illegal cast. If a cast doesn't match any of the "real" ones,
19// it will match this one.
20struct IllegalCast;
21template <typename T> IllegalCast *cast(...) { return 0; }
22
23// set up two example classes
24// with conversion facility
25//
26struct bar {
27  bar() {}
28  struct foo *baz();
29  struct foo *caz();
30  struct foo *daz();
31  struct foo *naz();
32private:
33  bar(const bar &);
34};
35struct foo {
36  void ext() const;
37  /*  static bool classof(const bar *X) {
38    cerr << "Classof: " << X << "\n";
39    return true;
40    }*/
41};
42
43template <> struct isa_impl<foo, bar> {
44  static inline bool doit(const bar &Val) {
45    dbgs() << "Classof: " << &Val << "\n";
46    return true;
47  }
48};
49
50foo *bar::baz() {
51    return cast<foo>(this);
52}
53
54foo *bar::caz() {
55    return cast_or_null<foo>(this);
56}
57
58foo *bar::daz() {
59    return dyn_cast<foo>(this);
60}
61
62foo *bar::naz() {
63    return dyn_cast_or_null<foo>(this);
64}
65
66
67bar *fub();
68
69template <> struct simplify_type<foo> {
70  typedef int SimpleType;
71  static SimpleType getSimplifiedValue(foo &Val) { return 0; }
72};
73
74} // End llvm namespace
75
76using namespace llvm;
77
78
79// Test the peculiar behavior of Use in simplify_type.
80int Check1[is_same<simplify_type<Use>::SimpleType, Value *>::value ? 1 : -1];
81int Check2[is_same<simplify_type<Use *>::SimpleType, Value *>::value ? 1 : -1];
82
83// Test that a regular class behaves as expected.
84int Check3[is_same<simplify_type<foo>::SimpleType, int>::value ? 1 : -1];
85int Check4[is_same<simplify_type<foo *>::SimpleType, foo *>::value ? 1 : -1];
86
87namespace {
88
89const foo *null_foo = NULL;
90
91bar B;
92extern bar &B1;
93bar &B1 = B;
94extern const bar *B2;
95// test various configurations of const
96const bar &B3 = B1;
97const bar *const B4 = B2;
98
99TEST(CastingTest, isa) {
100  EXPECT_TRUE(isa<foo>(B1));
101  EXPECT_TRUE(isa<foo>(B2));
102  EXPECT_TRUE(isa<foo>(B3));
103  EXPECT_TRUE(isa<foo>(B4));
104}
105
106TEST(CastingTest, cast) {
107  foo &F1 = cast<foo>(B1);
108  EXPECT_NE(&F1, null_foo);
109  const foo *F3 = cast<foo>(B2);
110  EXPECT_NE(F3, null_foo);
111  const foo *F4 = cast<foo>(B2);
112  EXPECT_NE(F4, null_foo);
113  const foo &F5 = cast<foo>(B3);
114  EXPECT_NE(&F5, null_foo);
115  const foo *F6 = cast<foo>(B4);
116  EXPECT_NE(F6, null_foo);
117  // Can't pass null pointer to cast<>.
118  // foo *F7 = cast<foo>(fub());
119  // EXPECT_EQ(F7, null_foo);
120  foo *F8 = B1.baz();
121  EXPECT_NE(F8, null_foo);
122}
123
124TEST(CastingTest, cast_or_null) {
125  const foo *F11 = cast_or_null<foo>(B2);
126  EXPECT_NE(F11, null_foo);
127  const foo *F12 = cast_or_null<foo>(B2);
128  EXPECT_NE(F12, null_foo);
129  const foo *F13 = cast_or_null<foo>(B4);
130  EXPECT_NE(F13, null_foo);
131  const foo *F14 = cast_or_null<foo>(fub());  // Shouldn't print.
132  EXPECT_EQ(F14, null_foo);
133  foo *F15 = B1.caz();
134  EXPECT_NE(F15, null_foo);
135}
136
137TEST(CastingTest, dyn_cast) {
138  const foo *F1 = dyn_cast<foo>(B2);
139  EXPECT_NE(F1, null_foo);
140  const foo *F2 = dyn_cast<foo>(B2);
141  EXPECT_NE(F2, null_foo);
142  const foo *F3 = dyn_cast<foo>(B4);
143  EXPECT_NE(F3, null_foo);
144  // Can't pass null pointer to dyn_cast<>.
145  // foo *F4 = dyn_cast<foo>(fub());
146  // EXPECT_EQ(F4, null_foo);
147  foo *F5 = B1.daz();
148  EXPECT_NE(F5, null_foo);
149}
150
151TEST(CastingTest, dyn_cast_or_null) {
152  const foo *F1 = dyn_cast_or_null<foo>(B2);
153  EXPECT_NE(F1, null_foo);
154  const foo *F2 = dyn_cast_or_null<foo>(B2);
155  EXPECT_NE(F2, null_foo);
156  const foo *F3 = dyn_cast_or_null<foo>(B4);
157  EXPECT_NE(F3, null_foo);
158  foo *F4 = dyn_cast_or_null<foo>(fub());
159  EXPECT_EQ(F4, null_foo);
160  foo *F5 = B1.naz();
161  EXPECT_NE(F5, null_foo);
162}
163
164// These lines are errors...
165//foo *F20 = cast<foo>(B2);  // Yields const foo*
166//foo &F21 = cast<foo>(B3);  // Yields const foo&
167//foo *F22 = cast<foo>(B4);  // Yields const foo*
168//foo &F23 = cast_or_null<foo>(B1);
169//const foo &F24 = cast_or_null<foo>(B3);
170
171const bar *B2 = &B;
172}  // anonymous namespace
173
174bar *llvm::fub() { return 0; }
175
176namespace {
177namespace inferred_upcasting {
178// This test case verifies correct behavior of inferred upcasts when the
179// types are statically known to be OK to upcast. This is the case when,
180// for example, Derived inherits from Base, and we do `isa<Base>(Derived)`.
181
182// Note: This test will actually fail to compile without inferred
183// upcasting.
184
185class Base {
186public:
187  // No classof. We are testing that the upcast is inferred.
188  Base() {}
189};
190
191class Derived : public Base {
192public:
193  Derived() {}
194};
195
196// Even with no explicit classof() in Base, we should still be able to cast
197// Derived to its base class.
198TEST(CastingTest, UpcastIsInferred) {
199  Derived D;
200  EXPECT_TRUE(isa<Base>(D));
201  Base *BP = dyn_cast<Base>(&D);
202  EXPECT_TRUE(BP != NULL);
203}
204
205
206// This test verifies that the inferred upcast takes precedence over an
207// explicitly written one. This is important because it verifies that the
208// dynamic check gets optimized away.
209class UseInferredUpcast {
210public:
211  int Dummy;
212  static bool classof(const UseInferredUpcast *) {
213    return false;
214  }
215};
216
217TEST(CastingTest, InferredUpcastTakesPrecedence) {
218  UseInferredUpcast UIU;
219  // Since the explicit classof() returns false, this will fail if the
220  // explicit one is used.
221  EXPECT_TRUE(isa<UseInferredUpcast>(&UIU));
222}
223
224} // end namespace inferred_upcasting
225} // end anonymous namespace
226// Test that we reject casts of temporaries (and so the illegal cast gets used).
227namespace TemporaryCast {
228struct pod {};
229IllegalCast *testIllegalCast() { return cast<foo>(pod()); }
230}
231