test/CodeGenCXX/catch-undef-behavior.cpp

// 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

struct S {
  double d;
  int a, b;
  virtual int f();
};

struct T : S {};

// CHECK: @_Z17reference_binding
void reference_binding(int *p, S *q) {
  // C++ core issue 453: If an lvalue to which a reference is directly bound
  // designates neither an existing object or function of an appropriate type,
  // nor a region of storage of suitable size and alignment to contain an object
  // of the reference's type, the behavior is undefined.

  // CHECK: icmp ne {{.*}}, null

  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64
  // CHECK-NEXT: icmp uge i64 %[[SIZE]], 4

  // CHECK: %[[PTRINT:.*]] = ptrtoint
  // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 3
  // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0
  int &r = *p;

  // A reference is not required to refer to an object within its lifetime.
  // CHECK-NOT: __ubsan_handle_dynamic_type_cache_miss
  S &r2 = *q;
}

// CHECK: @_Z13member_access
void member_access(S *p) {
  // (1a) Check 'p' is appropriately sized and aligned for member access.

  // CHECK: icmp ne {{.*}}, null

  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64
  // CHECK-NEXT: icmp uge i64 %[[SIZE]], 24

  // CHECK: %[[PTRINT:.*]] = ptrtoint
  // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 7
  // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0

  // (1b) Check that 'p' actually points to an 'S'.

  // CHECK: %[[VPTRADDR:.*]] = bitcast {{.*}} to i64*
  // CHECK-NEXT: %[[VPTR:.*]] = load i64* %[[VPTRADDR]]
  //
  // hash_16_bytes:
  //
  // If this number changes, it indicates that either the mangled name of ::S
  // has changed, or that LLVM's hashing function has changed. The latter case
  // is OK if the hashing function is still stable.
  //
  // The two hash values are for 64- and 32-bit Clang binaries, respectively.
  // FIXME: We should produce a 64-bit value either way.
  //
  // CHECK-NEXT: xor i64 {{-4030275160588942838|2562089159}}, %[[VPTR]]
  // CHECK-NEXT: mul i64 {{.*}}, -7070675565921424023
  // CHECK-NEXT: lshr i64 {{.*}}, 47
  // CHECK-NEXT: xor i64
  // CHECK-NEXT: xor i64 %[[VPTR]]
  // CHECK-NEXT: mul i64 {{.*}}, -7070675565921424023
  // CHECK-NEXT: lshr i64 {{.*}}, 47
  // CHECK-NEXT: xor i64
  // CHECK-NEXT: %[[HASH:.*]] = mul i64 {{.*}}, -7070675565921424023
  //
  // Check the hash against the table:
  //
  // CHECK-NEXT: %[[IDX:.*]] = and i64 %{{.*}}, 127
  // CHECK-NEXT: getelementptr inbounds [128 x i64]* @__ubsan_vptr_type_cache, i32 0, i64 %[[IDX]]
  // CHECK-NEXT: %[[CACHEVAL:.*]] = load i64*
  // CHECK-NEXT: icmp eq i64 %[[CACHEVAL]], %[[HASH]]
  // CHECK-NEXT: br i1

  // CHECK: call void @__ubsan_handle_dynamic_type_cache_miss({{.*}}, i64 %{{.*}}, i64 %[[HASH]])
  // CHECK-NOT: unreachable
  // CHECK: {{.*}}:

  // (2) Check 'p->b' is appropriately sized and aligned for a load.

  // FIXME: Suppress this in the trivial case of a member access, because we
  // know we've just checked the member access expression itself.

  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64
  // CHECK-NEXT: icmp uge i64 %[[SIZE]], 4

  // CHECK: %[[PTRINT:.*]] = ptrtoint
  // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 3
  // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0
  int k = p->b;

  // (3a) Check 'p' is appropriately sized and aligned for member function call.

  // CHECK: icmp ne {{.*}}, null

  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64
  // CHECK-NEXT: icmp uge i64 %[[SIZE]], 24

  // CHECK: %[[PTRINT:.*]] = ptrtoint
  // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 7
  // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0

  // (3b) Check that 'p' actually points to an 'S'

  // CHECK: load i64*
  // CHECK-NEXT: xor i64 {{-4030275160588942838|2562089159}},
  // [...]
  // CHECK: getelementptr inbounds [128 x i64]* @__ubsan_vptr_type_cache, i32 0, i64 %
  // CHECK: br i1
  // CHECK: call void @__ubsan_handle_dynamic_type_cache_miss({{.*}}, i64 %{{.*}}, i64 %{{.*}})
  // CHECK-NOT: unreachable
  // CHECK: {{.*}}:

  k = p->f();
}

// CHECK: @_Z12lsh_overflow
int lsh_overflow(int a, int b) {
  // CHECK: %[[INBOUNDS:.*]] = icmp ule i32 %[[RHS:.*]], 31
  // CHECK-NEXT: br i1 %[[INBOUNDS]]

  // CHECK: %[[SHIFTED_OUT_WIDTH:.*]] = sub nuw nsw i32 31, %[[RHS]]
  // CHECK-NEXT: %[[SHIFTED_OUT:.*]] = lshr i32 %[[LHS:.*]], %[[SHIFTED_OUT_WIDTH]]

  // This is present for C++11 but not for C: C++ core issue 1457 allows a '1'
  // to be shifted into the sign bit, but not out of it.
  // CHECK-NEXT: %[[SHIFTED_OUT_NOT_SIGN:.*]] = lshr i32 %[[SHIFTED_OUT]], 1

  // CHECK-NEXT: %[[NO_OVERFLOW:.*]] = icmp eq i32 %[[SHIFTED_OUT_NOT_SIGN]], 0

  // CHECK: %[[VALID:.*]] = phi i1 [ %[[INBOUNDS]], {{.*}} ], [ %[[NO_OVERFLOW]], {{.*}} ]
  // CHECK-NEXT: br i1 %[[VALID]]

  // CHECK: call void @__ubsan_handle_shift_out_of_bounds
  // CHECK-NOT: call void @__ubsan_handle_shift_out_of_bounds

  // CHECK: %[[RET:.*]] = shl i32 %[[LHS]], %[[RHS]]
  // CHECK-NEXT: ret i32 %[[RET]]
  return a << b;
}

// CHECK: @_Z9no_return
int no_return() {
  // CHECK:      call void @__ubsan_handle_missing_return(i8* bitcast ({{.*}}* @{{.*}} to i8*)) [[NR_NUW:#[0-9]+]]
  // CHECK-NEXT: unreachable
}

// CHECK: @_Z9sour_bool
bool sour_bool(bool *p) {
  // CHECK: %[[OK:.*]] = icmp ule i8 {{.*}}, 1
  // CHECK: br i1 %[[OK]]
  // CHECK: call void @__ubsan_handle_load_invalid_value(i8* bitcast ({{.*}}), i64 {{.*}})
  return *p;
}

enum E1 { e1a = 0, e1b = 127 } e1;
enum E2 { e2a = -1, e2b = 64 } e2;
enum E3 { e3a = (1u << 31) - 1 } e3;

// CHECK: @_Z14bad_enum_value
int bad_enum_value() {
  // CHECK: %[[E1:.*]] = icmp ule i32 {{.*}}, 127
  // CHECK: br i1 %[[E1]]
  // CHECK: call void @__ubsan_handle_load_invalid_value(
  int a = e1;

  // CHECK: %[[E2HI:.*]] = icmp sle i32 {{.*}}, 127
  // CHECK: %[[E2LO:.*]] = icmp sge i32 {{.*}}, -128
  // CHECK: %[[E2:.*]] = and i1 %[[E2HI]], %[[E2LO]]
  // CHECK: br i1 %[[E2]]
  // CHECK: call void @__ubsan_handle_load_invalid_value(
  int b = e2;

  // CHECK: %[[E3:.*]] = icmp ule i32 {{.*}}, 2147483647
  // CHECK: br i1 %[[E3]]
  // CHECK: call void @__ubsan_handle_load_invalid_value(
  int c = e3;
  return a + b + c;
}

// CHECK: @_Z20bad_downcast_pointer
void bad_downcast_pointer(S *p) {
  // CHECK: %[[NONNULL:.*]] = icmp ne {{.*}}, null
  // CHECK: br i1 %[[NONNULL]],

  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64(
  // CHECK: %[[E1:.*]] = icmp uge i64 %[[SIZE]], 24
  // CHECK: %[[MISALIGN:.*]] = and i64 %{{.*}}, 7
  // CHECK: %[[E2:.*]] = icmp eq i64 %[[MISALIGN]], 0
  // CHECK: %[[E12:.*]] = and i1 %[[E1]], %[[E2]]
  // CHECK: br i1 %[[E12]],

  // CHECK: call void @__ubsan_handle_type_mismatch
  // CHECK: br label

  // CHECK: br i1 %{{.*}},

  // CHECK: call void @__ubsan_handle_dynamic_type_cache_miss
  // CHECK: br label
  (void) static_cast<T*>(p);
}

// CHECK: @_Z22bad_downcast_reference
void bad_downcast_reference(S &p) {
  // CHECK: %[[E1:.*]] = icmp ne {{.*}}, null
  // CHECK-NOT: br i1
  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64(
  // CHECK: %[[E2:.*]] = icmp uge i64 %[[SIZE]], 24
  // CHECK: %[[E12:.*]] = and i1 %[[E1]], %[[E2]]
  // CHECK: %[[MISALIGN:.*]] = and i64 %{{.*}}, 7
  // CHECK: %[[E3:.*]] = icmp eq i64 %[[MISALIGN]], 0
  // CHECK: %[[E123:.*]] = and i1 %[[E12]], %[[E3]]
  // CHECK: br i1 %[[E123]],

  // CHECK: call void @__ubsan_handle_type_mismatch
  // CHECK: br label

  // CHECK: br i1 %{{.*}},

  // CHECK: call void @__ubsan_handle_dynamic_type_cache_miss
  // CHECK: br label
  (void) static_cast<T&>(p);
}

// CHECK: @_Z11array_index
int array_index(const int (&a)[4], int n) {
  // CHECK: %[[K1_OK:.*]] = icmp ult i64 %{{.*}}, 4
  // CHECK: br i1 %[[K1_OK]]
  // CHECK: call void @__ubsan_handle_out_of_bounds(
  int k1 = a[n];

  // CHECK: %[[R1_OK:.*]] = icmp ule i64 %{{.*}}, 4
  // CHECK: br i1 %[[R1_OK]]
  // CHECK: call void @__ubsan_handle_out_of_bounds(
  const int *r1 = &a[n];

  // CHECK: %[[K2_OK:.*]] = icmp ult i64 %{{.*}}, 8
  // CHECK: br i1 %[[K2_OK]]
  // CHECK: call void @__ubsan_handle_out_of_bounds(
  int k2 = ((const int(&)[8])a)[n];

  // CHECK: %[[K3_OK:.*]] = icmp ult i64 %{{.*}}, 4
  // CHECK: br i1 %[[K3_OK]]
  // CHECK: call void @__ubsan_handle_out_of_bounds(
  int k3 = n[a];

  return k1 + *r1 + k2;
}

// CHECK: @_Z17multi_array_index
int multi_array_index(int n, int m) {
  int arr[4][6];

  // CHECK: %[[IDX2_OK:.*]] = icmp ult i64 %{{.*}}, 6
  // CHECK: br i1 %[[IDX2_OK]]
  // CHECK: call void @__ubsan_handle_out_of_bounds(

  // CHECK: %[[IDX1_OK:.*]] = icmp ult i64 %{{.*}}, 4
  // CHECK: br i1 %[[IDX1_OK]]
  // CHECK: call void @__ubsan_handle_out_of_bounds(
  return arr[n][m];
}

// CHECK: @_Z11array_arith
int array_arith(const int (&a)[4], int n) {
  // CHECK: %[[K1_OK:.*]] = icmp ule i64 %{{.*}}, 4
  // CHECK: br i1 %[[K1_OK]]
  // CHECK: call void @__ubsan_handle_out_of_bounds(
  const int *k1 = a + n;

  // CHECK: %[[K2_OK:.*]] = icmp ule i64 %{{.*}}, 8
  // CHECK: br i1 %[[K2_OK]]
  // CHECK: call void @__ubsan_handle_out_of_bounds(
  const int *k2 = (const int(&)[8])a + n;

  return *k1 + *k2;
}

struct ArrayMembers {
  int a1[5];
  int a2[1];
};
// CHECK: @_Z18struct_array_index
int struct_array_index(ArrayMembers *p, int n) {
  // CHECK: %[[IDX_OK:.*]] = icmp ult i64 %{{.*}}, 5
  // CHECK: br i1 %[[IDX_OK]]
  // CHECK: call void @__ubsan_handle_out_of_bounds(
  return p->a1[n];
}

// CHECK: @_Z16flex_array_index
int flex_array_index(ArrayMembers *p, int n) {
  // CHECK-NOT: call void @__ubsan_handle_out_of_bounds(
  return p->a2[n];
}

extern int incomplete[];
// CHECK: @_Z22incomplete_array_index
int incomplete_array_index(int n) {
  // CHECK-NOT: call void @__ubsan_handle_out_of_bounds(
  return incomplete[n];
}

typedef __attribute__((ext_vector_type(4))) int V4I;
// CHECK: @_Z12vector_index
int vector_index(V4I v, int n) {
  // CHECK: %[[IDX_OK:.*]] = icmp ult i64 %{{.*}}, 4
  // CHECK: br i1 %[[IDX_OK]]
  // CHECK: call void @__ubsan_handle_out_of_bounds(
  return v[n];
}

// CHECK: @_Z12string_index
char string_index(int n) {
  // CHECK: %[[IDX_OK:.*]] = icmp ult i64 %{{.*}}, 6
  // CHECK: br i1 %[[IDX_OK]]
  // CHECK: call void @__ubsan_handle_out_of_bounds(
  return "Hello"[n];
}

// CHECK: attributes [[NR_NUW]] = { noreturn nounwind }