clang/test/SemaCXX/warn-unsafe-buffer-usage-fixits-local-var-span.cpp

   1 // RUN: %clang_cc1 -std=c++20 -Wunsafe-buffer-usage \
   2 // RUN:            -fsafe-buffer-usage-suggestions \
   3 // RUN:            -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s
   4 typedef int * Int_ptr_t;
   5 typedef int Int_t;
   6
   7 void local_array_subscript_simple() {
   8   int tmp;
   9   int *p = new int[10];
  10   // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:11}:"std::span<int> p"
  11   // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:12-[[@LINE-2]]:12}:"{"
  12   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:23-[[@LINE-3]]:23}:", 10}"
  13   const int *q = new int[10];
  14   // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:17}:"std::span<int const> q"
  15   // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:18-[[@LINE-2]]:18}:"{"
  16   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:29-[[@LINE-3]]:29}:", 10}"
  17   tmp = p[5];
  18   tmp = q[5];
  19
  20   // We do not fix the following declaration. Because if the
  21   // definition of `Int_ptr_t` gets changed, the fixed code becomes
  22   // incorrect and may NOT be noticed.
  23   // FIXME: Fix with std::span<std::remove_pointer_t<Int_ptr_t>>?
  24   Int_ptr_t x = new int[10];
  25   // CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-1]]
  26   Int_t * z = new int[10];
  27   // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:14}:"std::span<Int_t> z"
  28   // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:15-[[@LINE-2]]:15}:"{"
  29   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:26-[[@LINE-3]]:26}:", 10}"
  30   Int_t * w = new Int_t[10];
  31   // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:14}:"std::span<Int_t> w"
  32   // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:15-[[@LINE-2]]:15}:"{"
  33   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:28-[[@LINE-3]]:28}:", 10}"
  34
  35   tmp = x[5];
  36   tmp = z[5];
  37   tmp = w[5];
  38 }
  39
  40 void local_array_subscript_auto() {
  41   int tmp;
  42   // We do not fix the following declaration because
  43   // that'd cause us to hardcode the element type.
  44   // FIXME: Can we use the C++17 class template argument deduction
  45   // to avoid spelling out the element type?
  46   auto p = new int[10];
  47   // CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-1]]
  48   tmp = p[5];
  49 }
  50
  51 void local_variable_qualifiers_specifiers() {
  52   int a[10];
  53   const int * p = a;
  54   // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:18}:"std::span<int const> p"
  55   // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:19-[[@LINE-2]]:19}:"{"
  56   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:20-[[@LINE-3]]:20}:", 10}"
  57   const int * const q = a;
  58   // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:24}:"std::span<int const> const q"
  59   // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:25-[[@LINE-2]]:25}:"{"
  60   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:26-[[@LINE-3]]:26}:", 10}"
  61   int tmp;
  62   tmp = p[5];
  63   tmp = q[5];
  64 }
  65
  66
  67 void local_array_subscript_variable_extent() {
  68   int n = 10;
  69   int tmp;
  70   int *p = new int[n];
  71   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:11}:"std::span<int> p"
  72   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-2]]:12-[[@LINE-2]]:12}:"{"
  73   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-3]]:22-[[@LINE-3]]:22}:", n}"
  74   // If the extent expression does not have a constant value, we cannot fill the extent for users...
  75   int *q = new int[n++];
  76   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:11}:"std::span<int> q"
  77   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-2]]:12-[[@LINE-2]]:12}:"{"
  78   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-3]]:24-[[@LINE-3]]:24}:", <# placeholder #>}"
  79   tmp = p[5];
  80   tmp = q[5];
  81 }
  82
  83
  84 void local_ptr_to_array() {
  85   int tmp;
  86   int n = 10;
  87   int a[10];
  88   int b[n];  // If the extent expression does not have a constant value, we cannot fill the extent for users...
  89   int *p = a;
  90   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:11}:"std::span<int> p"
  91   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-2]]:12-[[@LINE-2]]:12}:"{"
  92   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-3]]:13-[[@LINE-3]]:13}:", 10}"
  93   int *q = b;
  94   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:11}:"std::span<int> q"
  95   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-2]]:12-[[@LINE-2]]:12}:"{"
  96   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-3]]:13-[[@LINE-3]]:13}:", <# placeholder #>}"
  97   // No way to know if `n` is ever mutated since `int b[n];`, so no way to figure out the extent
  98   tmp = p[5];
  99   tmp = q[5];
 100 }
 101
 102 void local_ptr_addrof_init() {
 103   int var;
 104   int * q = &var;
 105   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:12}:"std::span<int> q"
 106   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-2]]:13-[[@LINE-2]]:13}:"{"
 107   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-3]]:17-[[@LINE-3]]:17}:", 1}"
 108   // This expression involves unsafe buffer accesses, which will crash
 109   // at runtime after applying the fix-it,
 110   var = q[5];
 111 }
 112
 113 void decl_without_init() {
 114   int tmp;
 115   int * p;
 116   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:10}:"std::span<int> p"
 117   // CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-2]]:{{^3}}
 118   Int_t * q;
 119   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:12}:"std::span<Int_t> q"
 120   // CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-2]]:{{^3}}
 121   tmp = p[5];
 122   tmp = q[5];
 123 }
 124
 125 // Explicit casts are required in the following cases. No way to
 126 // figure out span extent for them automatically.
 127 void explict_cast() {
 128   int tmp;
 129   int * p = (int*) new int[10][10];
 130   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:12}:"std::span<int> p"
 131   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-2]]:13-[[@LINE-2]]:13}:"{"
 132   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-3]]:35-[[@LINE-3]]:35}:", <# placeholder #>}"
 133   tmp = p[5];
 134
 135   int a;
 136   char * q = (char *)&a;
 137   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:13}:"std::span<char> q"
 138   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-2]]:14-[[@LINE-2]]:14}:"{"
 139   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-3]]:24-[[@LINE-3]]:24}:", <# placeholder #>}"
 140   tmp = (int) q[5];
 141
 142   void * r = &a;
 143   char * s = (char *) r;
 144   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:13}:"std::span<char> s"
 145   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-2]]:14-[[@LINE-2]]:14}:"{"
 146   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-3]]:24-[[@LINE-3]]:24}:", <# placeholder #>}"
 147   tmp = (int) s[5];
 148 }
 149
 150 void null_init() {
 151 #define NULL 0
 152   int tmp;
 153   int * my_null = 0;
 154   int * p = 0;
 155   // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:12}:"std::span<int> p"
 156   // CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-2]]:{{^3}}
 157   int * g = NULL; // cannot handle fix-its involving macros for now
 158   // CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-1]]:
 159   int * f = nullptr;
 160   // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:12}:"std::span<int> f"
 161   // CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-2]]:{{^3}}
 162
 163   // In case of value dependencies, we give up
 164   int * q = my_null;
 165   // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:12}:"std::span<int> q"
 166   // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:13-[[@LINE-2]]:13}:"{"
 167   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:20-[[@LINE-3]]:20}:", <# placeholder #>}"
 168   int * r = my_null + 0;
 169   // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:12}:"std::span<int> r"
 170   // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:13-[[@LINE-2]]:13}:"{"
 171   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:24-[[@LINE-3]]:24}:", <# placeholder #>}"
 172
 173   tmp = p[5]; // `p[5]` will cause crash after `p` being transformed to be a `std::span`
 174   tmp = q[5]; // Similar for the rests.
 175   tmp = r[5];
 176   tmp = g[5];
 177   tmp = f[5];
 178 #undef NULL
 179 }
 180
 181
 182 void unsupported_multi_decl(int * x) {
 183   int * p = x, * q = new int[10];
 184   // CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-1]]
 185   *p = q[5];
 186 }
 187
 188 void macroVariableIdentifier() {
 189 #define MY_NAME p
 190 #define MY_NAME_ARG(x) q
 191
 192   // Although fix-its include macros, the macros do not overlap with
 193   // the bounds of the source range of these fix-its. So these fix-its
 194   // are valid.
 195
 196   int * MY_NAME = new int[10];
 197   // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:18}:"std::span<int> MY_NAME"
 198   // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:19-[[@LINE-2]]:19}:"{"
 199   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:30-[[@LINE-3]]:30}:", 10}"
 200   int * MY_NAME_ARG( 'x' ) = new int[10];
 201   // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:29}:"std::span<int> MY_NAME_ARG( 'x' )"
 202   // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:30-[[@LINE-2]]:30}:"{"
 203   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:41-[[@LINE-3]]:41}:", 10}"
 204   p[5] = 5;
 205   q[5] = 5;
 206 #undef MY_NAME
 207 #undef MY_NAME_ARG
 208 }
 209
 210 void unsupported_fixit_overlapping_macro(int * x) {
 211   int tmp;
 212   // In the case below, a tentative fix-it replaces `MY_INT * p =` with `std::span<MY_INT> p `.
 213   // The bounds of the source range of the fix-it overlap with the use of the macro
 214   // `MY_INT`.  The fix-it is discarded then.
 215
 216   // FIXME: we do not have to discard a fix-it if its begin location
 217   // overlaps with the begin location of a macro. Similar for end
 218   // locations.
 219
 220 #define MY_INT int
 221   MY_INT * p = new int[10];
 222   // CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-1]]
 223   tmp = p[5];
 224
 225 #define MY_VAR(name) int * name
 226   MY_VAR(q) = new int[10];
 227   // CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-1]]
 228   tmp = q[5];
 229
 230   // In cases where fix-its do not change the original code where
 231   // macros are used, those fix-its will be emitted.  For example,
 232   // fixits are inserted before and after `new MY_INT[MY_TEN]` below.
 233 #define MY_TEN 10
 234   int * g = new MY_INT[MY_TEN];
 235   // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:12}:"std::span<int> g"
 236   // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:13-[[@LINE-2]]:13}:"{"
 237   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:31-[[@LINE-3]]:31}:", MY_TEN}"
 238   tmp = g[5];
 239
 240 #undef MY_INT
 241 #undef MY_VAR
 242 #undef MY_TEN
 243 }
 244
 245 void unsupported_subscript_negative(int i, unsigned j, unsigned long k) {
 246   int tmp;
 247   int * p = new int[10];
 248   // CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-1]]
 249
 250   tmp = p[-1]; // If `p` is made a span, this `[]` operation is wrong,
 251          // so no fix-it emitted.
 252
 253   int * q = new int[10];
 254   // CHECK-NOT: fix-it:"{{.*}}":{[[@LINE-1]]
 255
 256   tmp = q[5];
 257   tmp = q[i];  // If `q` is made a span, this `[]` operation may be
 258          // wrong as we do not know if `i` is non-negative, so
 259          // no fix-it emitted.
 260
 261   int * r = new int[10];
 262   // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:12}:"std::span<int> r"
 263   // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:13-[[@LINE-2]]:13}:"{"
 264   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:24-[[@LINE-3]]:24}:", 10}"
 265
 266   tmp = r[j] + r[k]; // both `j` and `k` are unsigned so they must be non-negative
 267   tmp = r[(unsigned int)-1]; // a cast-to-unsigned-expression is also non-negative
 268 }
 269
 270 #define DEFINE_PTR(X) int* ptr = (X);
 271
 272 void all_vars_in_macro() {
 273   int* local;
 274   DEFINE_PTR(local)
 275   ptr[1] = 0;
 276 }
 277
 278 void few_vars_in_macro() {
 279   int* local;
 280   DEFINE_PTR(local)
 281   ptr[1] = 0;
 282   int tmp;
 283   ptr[2] = 30;
 284   int * p = new int[10];
 285   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:3-[[@LINE-1]]:12}:"std::span<int> p"
 286   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-2]]:13-[[@LINE-2]]:13}:"{"
 287   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-3]]:24-[[@LINE-3]]:24}:", 10}"
 288   tmp = p[5];
 289   int val = *p;
 290   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:13-[[@LINE-1]]:14}:""
 291   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-2]]:15-[[@LINE-2]]:15}:"[0]"
 292   val = *p + 30;
 293   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-1]]:9-[[@LINE-1]]:10}:""
 294   // CHECK-DAG: fix-it:"{{.*}}":{[[@LINE-2]]:11-[[@LINE-2]]:11}:"[0]"
 295 }