catch-undef-behavior.cpp revision 5956bcc31ad0b1f570e04f7e19e817112f7274c5 
1// RUN: %clang_cc1 -fsanitize=signed-integer-overflow,integer-divide-by-zero,float-divide-by-zero,shift,unreachable,return,vla-bound,alignment,null,vptr,object-size,float-cast-overflow,bool,enum,bounds -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s
2
3struct S {
4  double d;
5  int a, b;
6  virtual int f();
7};
8
9struct T : S {};
10
11// CHECK: @_Z17reference_binding
12void reference_binding(int *p, S *q) {
13  // C++ core issue 453: If an lvalue to which a reference is directly bound
14  // designates neither an existing object or function of an appropriate type,
15  // nor a region of storage of suitable size and alignment to contain an object
16  // of the reference's type, the behavior is undefined.
17
18  // CHECK: icmp ne {{.*}}, null
19
20  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64
21  // CHECK-NEXT: icmp uge i64 %[[SIZE]], 4
22
23  // CHECK: %[[PTRINT:.*]] = ptrtoint
24  // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 3
25  // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0
26  int &r = *p;
27
28  // A reference is not required to refer to an object within its lifetime.
29  // CHECK-NOT: __ubsan_handle_dynamic_type_cache_miss
30  S &r2 = *q;
31}
32
33// CHECK: @_Z13member_access
34void member_access(S *p) {
35  // (1a) Check 'p' is appropriately sized and aligned for member access.
36
37  // CHECK: icmp ne {{.*}}, null
38
39  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64
40  // CHECK-NEXT: icmp uge i64 %[[SIZE]], 24
41
42  // CHECK: %[[PTRINT:.*]] = ptrtoint
43  // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 7
44  // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0
45
46  // (1b) Check that 'p' actually points to an 'S'.
47
48  // CHECK: %[[VPTRADDR:.*]] = bitcast {{.*}} to i64*
49  // CHECK-NEXT: %[[VPTR:.*]] = load i64* %[[VPTRADDR]]
50  //
51  // hash_16_bytes:
52  //
53  // If this number changes, it indicates that either the mangled name of ::S
54  // has changed, or that LLVM's hashing function has changed. The latter case
55  // is OK if the hashing function is still stable.
56  //
57  // The two hash values are for 64- and 32-bit Clang binaries, respectively.
58  // FIXME: We should produce a 64-bit value either way.
59  //
60  // CHECK-NEXT: xor i64 {{-4030275160588942838|2562089159}}, %[[VPTR]]
61  // CHECK-NEXT: mul i64 {{.*}}, -7070675565921424023
62  // CHECK-NEXT: lshr i64 {{.*}}, 47
63  // CHECK-NEXT: xor i64
64  // CHECK-NEXT: xor i64 %[[VPTR]]
65  // CHECK-NEXT: mul i64 {{.*}}, -7070675565921424023
66  // CHECK-NEXT: lshr i64 {{.*}}, 47
67  // CHECK-NEXT: xor i64
68  // CHECK-NEXT: %[[HASH:.*]] = mul i64 {{.*}}, -7070675565921424023
69  //
70  // Check the hash against the table:
71  //
72  // CHECK-NEXT: %[[IDX:.*]] = and i64 %{{.*}}, 127
73  // CHECK-NEXT: getelementptr inbounds [128 x i64]* @__ubsan_vptr_type_cache, i32 0, i64 %[[IDX]]
74  // CHECK-NEXT: %[[CACHEVAL:.*]] = load i64*
75  // CHECK-NEXT: icmp eq i64 %[[CACHEVAL]], %[[HASH]]
76  // CHECK-NEXT: br i1
77
78  // CHECK: call void @__ubsan_handle_dynamic_type_cache_miss({{.*}}, i64 %{{.*}}, i64 %[[HASH]])
79  // CHECK-NOT: unreachable
80  // CHECK: {{.*}}:
81
82  // (2) Check 'p->b' is appropriately sized and aligned for a load.
83
84  // FIXME: Suppress this in the trivial case of a member access, because we
85  // know we've just checked the member access expression itself.
86
87  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64
88  // CHECK-NEXT: icmp uge i64 %[[SIZE]], 4
89
90  // CHECK: %[[PTRINT:.*]] = ptrtoint
91  // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 3
92  // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0
93  int k = p->b;
94
95  // (3a) Check 'p' is appropriately sized and aligned for member function call.
96
97  // CHECK: icmp ne {{.*}}, null
98
99  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64
100  // CHECK-NEXT: icmp uge i64 %[[SIZE]], 24
101
102  // CHECK: %[[PTRINT:.*]] = ptrtoint
103  // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 7
104  // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0
105
106  // (3b) Check that 'p' actually points to an 'S'
107
108  // CHECK: load i64*
109  // CHECK-NEXT: xor i64 {{-4030275160588942838|2562089159}},
110  // [...]
111  // CHECK: getelementptr inbounds [128 x i64]* @__ubsan_vptr_type_cache, i32 0, i64 %
112  // CHECK: br i1
113  // CHECK: call void @__ubsan_handle_dynamic_type_cache_miss({{.*}}, i64 %{{.*}}, i64 %{{.*}})
114  // CHECK-NOT: unreachable
115  // CHECK: {{.*}}:
116
117  k = p->f();
118}
119
120// CHECK: @_Z12lsh_overflow
121int lsh_overflow(int a, int b) {
122  // CHECK: %[[INBOUNDS:.*]] = icmp ule i32 %[[RHS:.*]], 31
123  // CHECK-NEXT: br i1 %[[INBOUNDS]]
124
125  // CHECK: %[[SHIFTED_OUT_WIDTH:.*]] = sub nuw nsw i32 31, %[[RHS]]
126  // CHECK-NEXT: %[[SHIFTED_OUT:.*]] = lshr i32 %[[LHS:.*]], %[[SHIFTED_OUT_WIDTH]]
127
128  // This is present for C++11 but not for C: C++ core issue 1457 allows a '1'
129  // to be shifted into the sign bit, but not out of it.
130  // CHECK-NEXT: %[[SHIFTED_OUT_NOT_SIGN:.*]] = lshr i32 %[[SHIFTED_OUT]], 1
131
132  // CHECK-NEXT: %[[NO_OVERFLOW:.*]] = icmp eq i32 %[[SHIFTED_OUT_NOT_SIGN]], 0
133  // CHECK-NEXT: br i1 %[[NO_OVERFLOW]]
134
135  // CHECK: %[[RET:.*]] = shl i32 %[[LHS]], %[[RHS]]
136  // CHECK-NEXT: ret i32 %[[RET]]
137  return a << b;
138}
139
140// CHECK: @_Z9no_return
141int no_return() {
142  // CHECK:      call void @__ubsan_handle_missing_return(i8* bitcast ({{.*}}* @{{.*}} to i8*)) [[NR_NUW:#[0-9]+]]
143  // CHECK-NEXT: unreachable
144}
145
146// CHECK: @_Z9sour_bool
147bool sour_bool(bool *p) {
148  // CHECK: %[[OK:.*]] = icmp ule i8 {{.*}}, 1
149  // CHECK: br i1 %[[OK]]
150  // CHECK: call void @__ubsan_handle_load_invalid_value(i8* bitcast ({{.*}}), i64 {{.*}})
151  return *p;
152}
153
154enum E1 { e1a = 0, e1b = 127 } e1;
155enum E2 { e2a = -1, e2b = 64 } e2;
156enum E3 { e3a = (1u << 31) - 1 } e3;
157
158// CHECK: @_Z14bad_enum_value
159int bad_enum_value() {
160  // CHECK: %[[E1:.*]] = icmp ule i32 {{.*}}, 127
161  // CHECK: br i1 %[[E1]]
162  // CHECK: call void @__ubsan_handle_load_invalid_value(
163  int a = e1;
164
165  // CHECK: %[[E2HI:.*]] = icmp sle i32 {{.*}}, 127
166  // CHECK: %[[E2LO:.*]] = icmp sge i32 {{.*}}, -128
167  // CHECK: %[[E2:.*]] = and i1 %[[E2HI]], %[[E2LO]]
168  // CHECK: br i1 %[[E2]]
169  // CHECK: call void @__ubsan_handle_load_invalid_value(
170  int b = e2;
171
172  // CHECK: %[[E3:.*]] = icmp ule i32 {{.*}}, 2147483647
173  // CHECK: br i1 %[[E3]]
174  // CHECK: call void @__ubsan_handle_load_invalid_value(
175  int c = e3;
176  return a + b + c;
177}
178
179// CHECK: @_Z20bad_downcast_pointer
180void bad_downcast_pointer(S *p) {
181  // CHECK: %[[NONNULL:.*]] = icmp ne {{.*}}, null
182  // CHECK: br i1 %[[NONNULL]],
183
184  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64(
185  // CHECK: %[[E1:.*]] = icmp uge i64 %[[SIZE]], 24
186  // CHECK: %[[MISALIGN:.*]] = and i64 %{{.*}}, 7
187  // CHECK: %[[E2:.*]] = icmp eq i64 %[[MISALIGN]], 0
188  // CHECK: %[[E12:.*]] = and i1 %[[E1]], %[[E2]]
189  // CHECK: br i1 %[[E12]],
190
191  // CHECK: call void @__ubsan_handle_type_mismatch
192  // CHECK: br label
193
194  // CHECK: br i1 %{{.*}},
195
196  // CHECK: call void @__ubsan_handle_dynamic_type_cache_miss
197  // CHECK: br label
198  (void) static_cast<T*>(p);
199}
200
201// CHECK: @_Z22bad_downcast_reference
202void bad_downcast_reference(S &p) {
203  // CHECK: %[[E1:.*]] = icmp ne {{.*}}, null
204  // CHECK-NOT: br i1
205  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64(
206  // CHECK: %[[E2:.*]] = icmp uge i64 %[[SIZE]], 24
207  // CHECK: %[[E12:.*]] = and i1 %[[E1]], %[[E2]]
208  // CHECK: %[[MISALIGN:.*]] = and i64 %{{.*}}, 7
209  // CHECK: %[[E3:.*]] = icmp eq i64 %[[MISALIGN]], 0
210  // CHECK: %[[E123:.*]] = and i1 %[[E12]], %[[E3]]
211  // CHECK: br i1 %[[E123]],
212
213  // CHECK: call void @__ubsan_handle_type_mismatch
214  // CHECK: br label
215
216  // CHECK: br i1 %{{.*}},
217
218  // CHECK: call void @__ubsan_handle_dynamic_type_cache_miss
219  // CHECK: br label
220  (void) static_cast<T&>(p);
221}
222
223// CHECK: @_Z11array_index
224int array_index(const int (&a)[4], int n) {
225  // CHECK: %[[K1_OK:.*]] = icmp ult i64 %{{.*}}, 4
226  // CHECK: br i1 %[[K1_OK]]
227  // CHECK: call void @__ubsan_handle_out_of_bounds(
228  int k1 = a[n];
229
230  // CHECK: %[[R1_OK:.*]] = icmp ule i64 %{{.*}}, 4
231  // CHECK: br i1 %[[R1_OK]]
232  // CHECK: call void @__ubsan_handle_out_of_bounds(
233  const int *r1 = &a[n];
234
235  // CHECK: %[[K2_OK:.*]] = icmp ult i64 %{{.*}}, 8
236  // CHECK: br i1 %[[K2_OK]]
237  // CHECK: call void @__ubsan_handle_out_of_bounds(
238  int k2 = ((const int(&)[8])a)[n];
239
240  // CHECK: %[[K3_OK:.*]] = icmp ult i64 %{{.*}}, 4
241  // CHECK: br i1 %[[K3_OK]]
242  // CHECK: call void @__ubsan_handle_out_of_bounds(
243  int k3 = n[a];
244
245  return k1 + *r1 + k2;
246}
247
248// CHECK: @_Z17multi_array_index
249int multi_array_index(int n, int m) {
250  int arr[4][6];
251
252  // CHECK: %[[IDX2_OK:.*]] = icmp ult i64 %{{.*}}, 6
253  // CHECK: br i1 %[[IDX2_OK]]
254  // CHECK: call void @__ubsan_handle_out_of_bounds(
255
256  // CHECK: %[[IDX1_OK:.*]] = icmp ult i64 %{{.*}}, 4
257  // CHECK: br i1 %[[IDX1_OK]]
258  // CHECK: call void @__ubsan_handle_out_of_bounds(
259  return arr[n][m];
260}
261
262// CHECK: @_Z11array_arith
263int array_arith(const int (&a)[4], int n) {
264  // CHECK: %[[K1_OK:.*]] = icmp ule i64 %{{.*}}, 4
265  // CHECK: br i1 %[[K1_OK]]
266  // CHECK: call void @__ubsan_handle_out_of_bounds(
267  const int *k1 = a + n;
268
269  // CHECK: %[[K2_OK:.*]] = icmp ule i64 %{{.*}}, 8
270  // CHECK: br i1 %[[K2_OK]]
271  // CHECK: call void @__ubsan_handle_out_of_bounds(
272  const int *k2 = (const int(&)[8])a + n;
273
274  return *k1 + *k2;
275}
276
277struct ArrayMembers {
278  int a1[5];
279  int a2[1];
280};
281// CHECK: @_Z18struct_array_index
282int struct_array_index(ArrayMembers *p, int n) {
283  // CHECK: %[[IDX_OK:.*]] = icmp ult i64 %{{.*}}, 5
284  // CHECK: br i1 %[[IDX_OK]]
285  // CHECK: call void @__ubsan_handle_out_of_bounds(
286  return p->a1[n];
287}
288
289// CHECK: @_Z16flex_array_index
290int flex_array_index(ArrayMembers *p, int n) {
291  // CHECK-NOT: call void @__ubsan_handle_out_of_bounds(
292  return p->a2[n];
293}
294
295extern int incomplete[];
296// CHECK: @_Z22incomplete_array_index
297int incomplete_array_index(int n) {
298  // CHECK-NOT: call void @__ubsan_handle_out_of_bounds(
299  return incomplete[n];
300}
301
302typedef __attribute__((ext_vector_type(4))) int V4I;
303// CHECK: @_Z12vector_index
304int vector_index(V4I v, int n) {
305  // CHECK: %[[IDX_OK:.*]] = icmp ult i64 %{{.*}}, 4
306  // CHECK: br i1 %[[IDX_OK]]
307  // CHECK: call void @__ubsan_handle_out_of_bounds(
308  return v[n];
309}
310
311// CHECK: @_Z12string_index
312char string_index(int n) {
313  // CHECK: %[[IDX_OK:.*]] = icmp ult i64 %{{.*}}, 6
314  // CHECK: br i1 %[[IDX_OK]]
315  // CHECK: call void @__ubsan_handle_out_of_bounds(
316  return "Hello"[n];
317}
318
319// CHECK: attributes [[NR_NUW]] = { noreturn nounwind }
320