ubsan_handlers.cc revision eda8bd0fc07df35c9ad7de5b698bb717b063e7af 
1//===-- ubsan_handlers.cc -------------------------------------------------===//
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// Error logging entry points for the UBSan runtime.
11//
12//===----------------------------------------------------------------------===//
13
14#include "ubsan_handlers.h"
15#include "ubsan_diag.h"
16
17#include "sanitizer_common/sanitizer_common.h"
18
19using namespace __sanitizer;
20using namespace __ubsan;
21
22NORETURN void __sanitizer::Die() {
23  __builtin_trap();
24}
25
26NORETURN void __sanitizer::CheckFailed(const char *File, int Line,
27                                       const char *Cond, u64 V1, u64 V2) {
28  Diag(SourceLocation(File, Line, 0),
29       "CHECK failed: %0 (with values %1 and %2)")
30    << Cond << V1 << V2;
31  Die();
32}
33
34namespace __ubsan {
35  const char *TypeCheckKinds[] = {
36    "load of", "store to", "reference binding to", "member access within",
37    "member call on", "constructor call on"
38  };
39}
40
41void __ubsan::__ubsan_handle_type_mismatch(TypeMismatchData *Data,
42                                           ValueHandle Pointer) {
43  if (!Pointer)
44    Diag(Data->Loc, "%0 null pointer of type %1")
45      << TypeCheckKinds[Data->TypeCheckKind] << Data->Type;
46  else if (Data->Alignment && (Pointer & (Data->Alignment - 1)))
47    Diag(Data->Loc, "%0 misaligned address %1 for type %3, "
48                    "which requires %2 byte alignment")
49      << TypeCheckKinds[Data->TypeCheckKind] << (void*)Pointer
50      << Data->Alignment << Data->Type;
51  else
52    Diag(Data->Loc, "%0 address %1 with insufficient space "
53                    "for an object of type %2")
54      << TypeCheckKinds[Data->TypeCheckKind] << (void*)Pointer << Data->Type;
55  Die();
56}
57
58/// \brief Common diagnostic emission for various forms of signed overflow.
59template<typename T> static void HandleSignedOverflow(OverflowData *Data,
60                                                      ValueHandle LHS,
61                                                      const char *Operator,
62                                                      T RHS) {
63  Diag(Data->Loc, "signed integer overflow: "
64                  "%0 %1 %2 cannot be represented in type %3")
65    << Value(Data->Type, LHS) << Operator << RHS << Data->Type;
66  Die();
67}
68
69void __ubsan::__ubsan_handle_add_overflow(OverflowData *Data,
70                                          ValueHandle LHS, ValueHandle RHS) {
71  HandleSignedOverflow(Data, LHS, "+", Value(Data->Type, RHS));
72}
73
74void __ubsan::__ubsan_handle_sub_overflow(OverflowData *Data,
75                                          ValueHandle LHS, ValueHandle RHS) {
76  HandleSignedOverflow(Data, LHS, "-", Value(Data->Type, RHS));
77}
78
79void __ubsan::__ubsan_handle_mul_overflow(OverflowData *Data,
80                                          ValueHandle LHS, ValueHandle RHS) {
81  HandleSignedOverflow(Data, LHS, "*", Value(Data->Type, RHS));
82}
83
84void __ubsan::__ubsan_handle_negate_overflow(OverflowData *Data,
85                                             ValueHandle OldVal) {
86  Diag(Data->Loc, "negation of %0 cannot be represented in type %1; "
87                  "cast to an unsigned type to negate this value to itself")
88    << Value(Data->Type, OldVal) << Data->Type;
89  Die();
90}
91
92void __ubsan::__ubsan_handle_divrem_overflow(OverflowData *Data,
93                                             ValueHandle LHS, ValueHandle RHS) {
94  Value LHSVal(Data->Type, LHS);
95  Value RHSVal(Data->Type, RHS);
96  if (RHSVal.isMinusOne())
97    Diag(Data->Loc, "division of %0 by -1 cannot be represented in type %1")
98      << LHSVal << Data->Type;
99  else
100    Diag(Data->Loc, "division by zero");
101  Die();
102}
103
104void __ubsan::__ubsan_handle_shift_out_of_bounds(ShiftOutOfBoundsData *Data,
105                                                 ValueHandle LHS,
106                                                 ValueHandle RHS) {
107  Value LHSVal(Data->LHSType, LHS);
108  Value RHSVal(Data->RHSType, RHS);
109  if (RHSVal.isNegative())
110    Diag(Data->Loc, "shift exponent %0 is negative") << RHSVal;
111  else if (RHSVal.getPositiveIntValue() >= Data->LHSType.getIntegerBitWidth())
112    Diag(Data->Loc, "shift exponent %0 is too large for %1-bit type %2")
113      << RHSVal << Data->LHSType.getIntegerBitWidth() << Data->LHSType;
114  else if (LHSVal.isNegative())
115    Diag(Data->Loc, "left shift of negative value %0") << LHSVal;
116  else
117    Diag(Data->Loc, "left shift of %0 by %1 places cannot be represented "
118                    "in type %2") << LHSVal << RHSVal << Data->LHSType;
119  Die();
120}
121
122void __ubsan::__ubsan_handle_builtin_unreachable(UnreachableData *Data) {
123  Diag(Data->Loc, "execution reached a __builtin_unreachable() call");
124  Die();
125}
126
127void __ubsan::__ubsan_handle_missing_return(UnreachableData *Data) {
128  Diag(Data->Loc, "execution reached the end of a value-returning function "
129                  "without returning a value");
130  Die();
131}
132
133void __ubsan::__ubsan_handle_vla_bound_not_positive(VLABoundData *Data,
134                                                    ValueHandle Bound) {
135  Diag(Data->Loc, "variable length array bound evaluates to "
136                  "non-positive value %0")
137    << Value(Data->Type, Bound);
138  Die();
139}
140
141void __ubsan::__ubsan_handle_float_cast_overflow(FloatCastOverflowData *Data,
142                                                 ValueHandle From) {
143  Diag(SourceLocation(), "value %0 is outside the range of representable "
144                         "values of type %2")
145    << Value(Data->FromType, From) << Data->FromType << Data->ToType;
146  Die();
147}
148