gcc/testsuite/gcc.dg/tree-ssa/builtin-sprintf-warn-23.c

   1 /* PR tree-optimization/35503 - Warning about restricted pointers?
   2    { dg-do compile }
   3    { dg-options "-O2 -Wno-format-overflow -Wrestrict -ftrack-macro-expansion=0" }
   4 */
   5
   6 void sink (int);
   7
   8 #define S10 "0123456789"
   9
  10 extern char a2[2][22];
  11
  12 #define T(d, ...) do {                                  \
  13     char a[22] = S10;                                   \
  14     sink (__builtin_sprintf ((d), __VA_ARGS__));        \
  15   } while (0)
  16
  17 void test_ptr (char *d, int i)
  18 {
  19   T (d, "%s", d);       /* { dg-warning "argument 3 overlaps destination object 'd'" } */
  20   T (d, "%s", d + 0);   /* { dg-warning "overlaps" } */
  21
  22   /* The following only overlaps if d[1] is non-zero.  */
  23   T (d, "%s", d + 1);   /* { dg-warning "may overlap" } */
  24   T (d, "%s", d + 2);   /* { dg-warning "may overlap" } */
  25   T (d, "%s", d + i);   /* { dg-warning "may overlap" } */
  26
  27   T (d, "%s", &d[0]);   /* { dg-warning "overlaps" } */
  28   T (d, "%s", &d[1]);   /* { dg-warning "may overlap" } */
  29   T (d, "%s", &d[2]);   /* { dg-warning "may overlap" } */
  30   T (d, "%s", &d[i]);   /* { dg-warning "may overlap" } */
  31
  32   T (d + 0, "%s", d);   /* { dg-warning "overlaps" } */
  33   T (d + 1, "%s", d);   /* { dg-warning "may overlap" } */
  34   T (d + 2, "%s", d);   /* { dg-warning "may overlap" } */
  35   T (d + i, "%s", d);   /* { dg-warning "may overlap" } */
  36
  37   T (&d[0], "%s", d);   /* { dg-warning "overlaps" } */
  38   T (&d[1], "%s", d);   /* { dg-warning "may overlap" } */
  39   T (&d[2], "%s", d);   /* { dg-warning "may overlap" } */
  40   T (&d[i], "%s", d);   /* { dg-warning "may overlap" } */
  41
  42   const char *s = d;
  43
  44   T (d, "%s", s);       /* { dg-warning "overlaps" } */
  45   T (d, "%s", s + 1);   /* { dg-warning "may overlap" } */
  46   T (d, "%s", s + 2);   /* { dg-warning "may overlap" } */
  47   T (d, "%s", s + i);   /* { dg-warning "may overlap" } */
  48 }
  49
  50 void test_ptr_plus (char *d, int i)
  51 {
  52   const char *s = d;
  53
  54   T (d, "%s", s++);     /* { dg-warning "overlaps" } */
  55   T (d, "%s", s++);     /* { dg-warning "may overlap" } */
  56   T (d, "%s", s++);     /* { dg-warning "may overlap" } */
  57   T (d, "%s", s++);     /* { dg-warning "may overlap" } */
  58
  59   s += i;
  60   T (d, "%s", s);       /* { dg-warning "may overlap" } */
  61 }
  62
  63 void test_array_1_dim (int i)
  64 {
  65   T (a, "%s", a);       /* { dg-warning "overlaps" } */
  66   T (a, "%s", a + 0);   /* { dg-warning "overlaps" } */
  67   T (a, "%s", a + 1);   /* { dg-warning "overlaps" } */
  68   T (a, "%s", a + 2);   /* { dg-warning "overlaps" } */
  69   T (a, "%s", a + i);   /* { dg-warning "may overlap" } */
  70
  71   T (a, "%s", &a[0]);   /* { dg-warning "overlaps" } */
  72   T (a, "%s", &a[1]);   /* { dg-warning "overlaps" } */
  73   T (a, "%s", &a[2]);   /* { dg-warning "overlaps" } */
  74   T (a, "%s", &a[i]);   /* { dg-warning "may overlap" } */
  75
  76   T (a + 0, "%s", a);   /* { dg-warning "overlaps" } */
  77   T (a + 1, "%s", a);   /* { dg-warning "overlaps" } */
  78   T (a + 2, "%s", a);   /* { dg-warning "overlaps" } */
  79   T (a + i, "%s", a);   /* { dg-warning "may overlap" } */
  80
  81   T (&a[0], "%s", a);   /* { dg-warning "overlaps" } */
  82   T (&a[1], "%s", a);   /* { dg-warning "overlaps" } */
  83   T (&a[2], "%s", a);   /* { dg-warning "overlaps" } */
  84   T (&a[i], "%s", a);   /* { dg-warning "may overlap" } */
  85 }
  86
  87
  88 void test_array_2_dim (int i)
  89 {
  90   T (a2[0], "%s", a2[0]);       /* { dg-warning "overlaps" } */
  91   T (a2[0], "%s", a2[0] + 0);   /* { dg-warning "overlaps" } */
  92   T (a2[0], "%s", a2[0] + 1);   /* { dg-warning "may overlap" } */
  93   T (a2[0], "%s", a2[0] + 2);   /* { dg-warning "may overlap" } */
  94   T (a2[0], "%s", a2[0] + i);   /* { dg-warning "may overlap" } */
  95
  96   T (a2[0], "%s", &a2[0][0]);   /* { dg-warning "overlaps" } */
  97   T (a2[0], "%s", &a2[0][1]);   /* { dg-warning "may overlap" } */
  98   T (a2[0], "%s", &a2[0][2]);   /* { dg-warning "may overlap" } */
  99   T (a2[0], "%s", &a2[0][i]);   /* { dg-warning "may overlap" } */
 100
 101   T (a2[0] + 0, "%s", a2[0]);   /* { dg-warning "overlaps" } */
 102   T (a2[0] + 1, "%s", a2[0]);   /* { dg-warning "may overlap" } */
 103   T (a2[0] + 2, "%s", a2[0]);   /* { dg-warning "may overlap" } */
 104   T (a2[0] + i, "%s", a2[0]);   /* { dg-warning "may overlap" } */
 105
 106   T (&a2[0][0], "%s", a2[0]);   /* { dg-warning "overlaps" } */
 107   T (&a2[0][1], "%s", a2[0]);   /* { dg-warning "may overlap" } */
 108   T (&a2[0][2], "%s", a2[0]);   /* { dg-warning "may overlap" } */
 109   T (&a2[0][i], "%s", a2[0]);   /* { dg-warning "may overlap" } */
 110
 111
 112   T (a2[0], "%s", a2[1]);
 113   T (a2[0], "%s", a2[1] + 0);
 114   T (a2[0], "%s", a2[1] + 1);
 115   T (a2[0], "%s", a2[1] + 2);
 116   T (a2[0], "%s", a2[1] + i);
 117
 118   T (a2[0], "%s", &a2[1][0]);
 119   T (a2[0], "%s", &a2[1][1]);
 120   T (a2[0], "%s", &a2[1][2]);
 121
 122   /* a2[0] is represented as &a in Gimple, and &a2[1][i] as &a + _2,
 123      with _1 defined to something like 10 + _1, and _1 to i.  That
 124      makes it virtually impossible to reliably determine that the
 125      two pointers refer to distinct sub-arrays of the same multi-
 126      dimensional array.  */
 127   T (a2[0], "%s", &a2[1][i]);   /* { dg-bogus "overlap" "" { xfail *-*-* } } */
 128
 129   T (a2[0] + 0, "%s", a2[1]);
 130   T (a2[0] + 1, "%s", a2[1]);
 131   T (a2[0] + 2, "%s", a2[1]);
 132   T (a2[0] + i, "%s", a2[1]);
 133
 134   T (&a2[0][0], "%s", a2[1]);
 135   T (&a2[0][1], "%s", a2[1]);
 136   T (&a2[0][2], "%s", a2[1]);
 137   T (&a2[0][i], "%s", a2[1]);
 138
 139
 140   T (a2[1], "%s", a2[0]);
 141   T (a2[1], "%s", a2[0] + 0);
 142   T (a2[1], "%s", a2[0] + 1);
 143   T (a2[1], "%s", a2[0] + 2);
 144   T (a2[1], "%s", a2[0] + i);
 145
 146   T (a2[1], "%s", &a2[0][0]);
 147   T (a2[1], "%s", &a2[0][1]);
 148   T (a2[1], "%s", &a2[0][2]);
 149   T (a2[1], "%s", &a2[0][i]);
 150
 151   T (a2[1] + 0, "%s", a2[0]);
 152   T (a2[1] + 1, "%s", a2[0]);
 153   T (a2[1] + 2, "%s", a2[0]);
 154   T (a2[1] + i, "%s", a2[0]);
 155
 156   T (&a2[1][0], "%s", a2[0]);
 157   T (&a2[1][1], "%s", a2[0]);
 158   T (&a2[1][2], "%s", a2[0]);
 159   T (&a2[1][i], "%s", a2[0]);   /* { dg-bogus "overlap" "" { xfail *-*-* } } */
 160
 161
 162   T (a2[1], "%s", a2[1]);       /* { dg-warning "overlaps" } */
 163   T (a2[1], "%s", a2[1] + 0);   /* { dg-warning "overlaps" } */
 164   T (a2[1], "%s", a2[1] + 1);   /* { dg-warning "may overlap" } */
 165   T (a2[1], "%s", a2[1] + 2);   /* { dg-warning "may overlap" } */
 166   T (a2[1], "%s", a2[1] + i);   /* { dg-warning "may overlap" } */
 167
 168   T (a2[1], "%s", &a2[1][0]);   /* { dg-warning "overlaps" } */
 169   T (a2[1], "%s", &a2[1][1]);   /* { dg-warning "may overlap" } */
 170   T (a2[1], "%s", &a2[1][2]);   /* { dg-warning "may overlap" } */
 171   T (a2[1], "%s", &a2[1][i]);   /* { dg-warning "may overlap" "" { xfail *-*-* } } */
 172
 173   T (a2[1] + 0, "%s", a2[1]);   /* { dg-warning "overlaps" } */
 174   T (a2[1] + 1, "%s", a2[1]);   /* { dg-warning "may overlap" } */
 175   T (a2[1] + 2, "%s", a2[1]);   /* { dg-warning "may overlap" } */
 176   T (a2[1] + i, "%s", a2[1]);   /* { dg-warning "may overlap" } */
 177
 178   T (&a2[1][0], "%s", a2[1]);   /* { dg-warning "overlaps" } */
 179   T (&a2[1][1], "%s", a2[1]);   /* { dg-warning "may overlap" } */
 180   T (&a2[1][2], "%s", a2[1]);   /* { dg-warning "may overlap" } */
 181   T (&a2[1][i], "%s", a2[1]);   /* { dg-warning "may overlap" "" { xfail *-*-* } } */
 182 }
 183
 184 struct S {
 185   char a[4];
 186   char b[4];
 187 };
 188
 189 struct S2 {
 190   struct S s_1;
 191   struct S s_2;
 192   struct S sa3[3];
 193 };
 194
 195 struct S3 {
 196   struct S2 s2_1;
 197   struct S2 s2_2;
 198
 199   struct {
 200     struct {
 201       struct {
 202         struct S sa_3[3];
 203       } a_1[3];
 204     } a_2[3][3];
 205   } a_3[3][3][3];
 206
 207   char fa[];
 208 };
 209
 210 void test_struct_member_array (struct S3 *s3, int i)
 211 {
 212   char *d = s3->s2_1.s_1.a;
 213
 214   T (d, "%s", d);       /* { dg-warning "overlaps" } */
 215   T (d, "%s", d + 0);   /* { dg-warning "overlaps" } */
 216   T (d, "%s", d + 1);   /* { dg-warning "may overlap" } */
 217   /* Since d below points to char[4], strlen(d + 2) must be at most 1
 218      and so the call cannot overlap. */
 219   T (d, "%s", d + 2);
 220   T (d, "%s", d + i);   /* { dg-warning "may overlap" } */
 221
 222   T (d, "%s", &d[0]);   /* { dg-warning "overlaps" } */
 223   T (d, "%s", &d[1]);   /* { dg-warning "may overlap" } */
 224   T (d, "%s", &d[2]);
 225   T (d, "%s", &d[i]);   /* { dg-warning "may overlap" } */
 226
 227   T (d + 0, "%s", d);   /* { dg-warning "overlaps" } */
 228   T (d + 1, "%s", d);   /* { dg-warning "may overlap" } */
 229   T (d + 2, "%s", d);   /* { dg-warning "may overlap" } */
 230   T (d + i, "%s", d);   /* { dg-warning "may overlap" } */
 231
 232   T (&d[0], "%s", d);   /* { dg-warning "overlaps" } */
 233   T (&d[1], "%s", d);   /* { dg-warning "may overlap" } */
 234   T (&d[2], "%s", d);   /* { dg-warning "may overlap" } */
 235   T (&d[i], "%s", d);   /* { dg-warning "may overlap" } */
 236
 237   const char *s = d;
 238
 239   T (d, "%s", s);       /* { dg-warning "overlaps" } */
 240   T (d, "%s", s + 1);   /* { dg-warning "may overlap" } */
 241   T (d, "%s", s + 2);
 242   T (d, "%s", s + i);   /* { dg-warning "may overlap" } */
 243
 244   s = s3->s2_1.s_1.b;
 245
 246   T (d, "%s", s);
 247   T (d, "%s", s + 1);
 248   T (d, "%s", s + 2);
 249   T (d, "%s", s + i);
 250
 251   s = s3->s2_1.s_2.a;
 252
 253   T (d, "%s", s);
 254   T (d, "%s", s + 1);
 255   T (d, "%s", s + 2);
 256   T (d, "%s", s + i);
 257
 258   s = s3->s2_1.s_2.b;
 259
 260   T (d, "%s", s);
 261   T (d, "%s", s + 1);
 262   T (d, "%s", s + 2);
 263   T (d, "%s", s + i);
 264
 265   d = s3->s2_1.s_1.b;
 266
 267   s = s3->s2_1.s_2.a;
 268
 269   T (d, "%s", s);
 270   T (d, "%s", s + 1);
 271   T (d, "%s", s + 2);
 272   T (d, "%s", s + i);
 273
 274   s = s3->s2_1.s_2.b;
 275
 276   T (d, "%s", s);
 277   T (d, "%s", s + 1);
 278   T (d, "%s", s + 2);
 279   T (d, "%s", s + i);
 280
 281   s = s3->s2_2.s_1.a;
 282
 283   T (d, "%s", s);
 284   T (d, "%s", s + 1);
 285   T (d, "%s", s + 2);
 286   T (d, "%s", s + i);
 287
 288   s = s3->s2_2.s_1.b;
 289
 290   T (d, "%s", s);
 291   T (d, "%s", s + 1);
 292   T (d, "%s", s + 2);
 293   T (d, "%s", s + i);
 294
 295   s = s3->s2_2.s_2.a;
 296
 297   T (d, "%s", s);
 298   T (d, "%s", s + 1);
 299   T (d, "%s", s + 2);
 300   T (d, "%s", s + i);
 301
 302   s = s3->s2_2.s_2.b;
 303
 304   T (d, "%s", s);
 305   T (d, "%s", s + 1);
 306   T (d, "%s", s + 2);
 307   T (d, "%s", s + i);
 308
 309   d = s3->s2_2.s_1.a;
 310
 311   s = s3->s2_1.s_1.a;
 312
 313   T (d, "%s", s);
 314   T (d, "%s", s + 1);
 315   T (d, "%s", s + 2);
 316   T (d, "%s", s + i);
 317
 318   s = s3->s2_1.s_1.b;
 319
 320   T (d, "%s", s);
 321   T (d, "%s", s + 1);
 322   T (d, "%s", s + 2);
 323   T (d, "%s", s + i);
 324
 325   s = s3->s2_2.s_1.a;
 326
 327   T (d, "%s", s);       /* { dg-warning "overlaps" } */
 328   T (d, "%s", s + 1);   /* { dg-warning "may overlap" } */
 329   T (d, "%s", s + 2);
 330   T (d, "%s", s + i);   /* { dg-warning "may overlap" } */
 331
 332   s = s3->s2_2.s_2.a;
 333
 334   T (d, "%s", s);
 335   T (d, "%s", s + 1);
 336   T (d, "%s", s + 2);
 337   T (d, "%s", s + i);
 338
 339   s = s3->s2_2.s_2.b;
 340
 341   T (d, "%s", s);
 342   T (d, "%s", s + 1);
 343   T (d, "%s", s + 2);
 344   T (d, "%s", s + i);
 345
 346   d = s3->s2_2.s_1.b;
 347
 348   s = s3->s2_1.s_1.a;
 349
 350   T (d, "%s", s);
 351   T (d, "%s", s + 1);
 352   T (d, "%s", s + 2);
 353   T (d, "%s", s + i);
 354
 355   s = s3->s2_1.s_1.b;
 356
 357   T (d, "%s", s);
 358   T (d, "%s", s + 1);
 359   T (d, "%s", s + 2);
 360   T (d, "%s", s + i);
 361
 362   s = s3->s2_2.s_1.a;
 363
 364   T (d, "%s", s);
 365   T (d, "%s", s + 1);
 366   T (d, "%s", s + 2);
 367   T (d, "%s", s + i);
 368
 369   s = s3->s2_2.s_1.b;
 370
 371   T (d, "%s", s);       /* { dg-warning "overlaps" } */
 372   T (d, "%s", s + 1);   /* { dg-warning "may overlap" } */
 373   T (d, "%s", s + 2);
 374   T (d, "%s", s + i);   /* { dg-warning "may overlap" } */
 375
 376   s = s3->s2_2.s_2.a;
 377
 378   T (d, "%s", s);
 379   T (d, "%s", s + 1);
 380   T (d, "%s", s + 2);
 381   T (d, "%s", s + i);
 382
 383   s = s3->s2_2.s_2.b;
 384
 385   T (d, "%s", s);
 386   T (d, "%s", s + 1);
 387   T (d, "%s", s + 2);
 388   T (d, "%s", s + i);
 389 }
 390
 391 void test_struct_member_array_array (struct S3 *s3, int i)
 392 {
 393   char *d = s3->s2_1.sa3[0].a;
 394   char *s = s3->s2_1.sa3[0].a;
 395
 396   T (d, "%s", s);       /* { dg-warning "overlaps" } */
 397   T (d, "%s", s + 0);   /* { dg-warning "overlaps" } */
 398   T (d, "%s", s + 1);   /* { dg-warning "may overlap" } */
 399   T (d, "%s", s + 2);
 400   T (d, "%s", s + i);   /* { dg-warning "may overlap" } */
 401
 402   T (d, "%s", &s[0]);   /* { dg-warning "overlaps" } */
 403   T (d, "%s", &s[1]);   /* { dg-warning "may overlap" } */
 404   T (d, "%s", &s[2]);
 405   T (d, "%s", &s[i]);   /* { dg-warning "may overlap" } */
 406
 407   T (d + 0, "%s", s);   /* { dg-warning "overlaps" } */
 408   T (d + 1, "%s", s);   /* { dg-warning "may overlap" } */
 409   T (d + 2, "%s", s);   /* { dg-warning "may overlap" } */
 410   T (d + i, "%s", s);   /* { dg-warning "may overlap" } */
 411
 412   T (&d[0], "%s", s);   /* { dg-warning "overlaps" } */
 413   T (&d[1], "%s", s);   /* { dg-warning "may overlap" } */
 414   T (&d[2], "%s", s);   /* { dg-warning "may overlap" } */
 415   T (&d[i], "%s", s);   /* { dg-warning "may overlap" } */
 416
 417   s = s3->s2_1.sa3[0].b;
 418
 419   T (d, "%s", s);
 420   T (d, "%s", s + 0);
 421   T (d, "%s", s + 1);
 422   T (d, "%s", s + 2);
 423   T (d, "%s", s + i);
 424
 425   T (d, "%s", &s[0]);
 426   T (d, "%s", &s[1]);
 427   T (d, "%s", &s[2]);
 428   T (d, "%s", &s[i]);
 429
 430   T (d + 0, "%s", s);
 431   T (d + 1, "%s", s);
 432   T (d + 2, "%s", s);
 433   T (d + i, "%s", s);
 434
 435   T (&d[0], "%s", s);
 436   T (&d[1], "%s", s);
 437   T (&d[2], "%s", s);
 438   T (&d[i], "%s", s);
 439 }
 440
 441 void test_struct_member_nested_array (struct S3 *s3, int i)
 442 {
 443 #define PFX(sfx) s3->a_3[i3_0][i3_1][i3_2]      \
 444     .a_2[i2_0][i2_1]                            \
 445     .a_1[i1_0].sfx
 446
 447 #define TT(d, s)                                \
 448   T (PFX (d), "%s", PFX (s));                   \
 449   T (PFX (d), "%s", &PFX (s)[0]);               \
 450   T (PFX (d), "%s", &PFX (s)[1]);               \
 451   T (PFX (d), "%s", &PFX (s)[2]);               \
 452   T (PFX (d), "%s", &PFX (s)[i])                \
 453
 454 #define T1(i0)  do                                              \
 455     {                                                           \
 456       enum {i1_0 = i0 };                                        \
 457                                                                 \
 458       TT (sa_3[0].a, sa_3[0].b); TT (sa_3[0].b, sa_3[0].a);     \
 459                                                                 \
 460       TT (sa_3[0].a, sa_3[1].a); TT (sa_3[0].a, sa_3[1].b);     \
 461       TT (sa_3[0].b, sa_3[1].a); TT (sa_3[0].b, sa_3[1].b);     \
 462                                                                 \
 463       TT (sa_3[0].a, sa_3[2].a); TT (sa_3[0].a, sa_3[2].b);     \
 464       TT (sa_3[0].b, sa_3[2].a); TT (sa_3[0].b, sa_3[2].b);     \
 465                                                                 \
 466       TT (sa_3[1].a, sa_3[0].a); TT (sa_3[1].a, sa_3[0].b);     \
 467       TT (sa_3[1].b, sa_3[0].a); TT (sa_3[1].b, sa_3[0].b);     \
 468                                                                 \
 469       TT (sa_3[1].a, sa_3[1].b); TT (sa_3[1].b, sa_3[1].a);     \
 470                                                                 \
 471       TT (sa_3[1].a, sa_3[2].a); TT (sa_3[1].a, sa_3[2].b);     \
 472       TT (sa_3[1].b, sa_3[2].a); TT (sa_3[1].b, sa_3[2].b);     \
 473     } while (0)
 474
 475 #define T2(i0, i1) do                           \
 476     {                                           \
 477       enum { i2_0 = i0, i2_1 = i1 };            \
 478       T1 (0); T1 (1); T1 (2);                   \
 479     } while (0)
 480
 481 #define T3(i0, i1, i2) do                       \
 482     {                                           \
 483       enum { i3_0 = i0, i3_1 = i1, i3_2 = i2 }; \
 484       T2 (0, 0); T2 (0, 1); T2 (0, 2);          \
 485       T2 (1, 0); T2 (1, 1); T2 (1, 2);          \
 486       T2 (2, 0); T2 (2, 1); T2 (2, 2);          \
 487     } while (0)
 488
 489 #if 0
 490   /* These tests take forever and a day to compile.  Enable them only
 491      during the development of this feature but leave them otherwise
 492      disabled to avoid slowing everything down for others.  */
 493   T3 (0, 0, 0); T3 (0, 0, 1); T3 (0, 0, 2);
 494   T3 (0, 1, 0); T3 (0, 1, 1); T3 (0, 1, 2);
 495   T3 (0, 2, 0); T3 (0, 2, 1); T3 (0, 2, 2);
 496
 497   T3 (1, 0, 0); T3 (1, 0, 1); T3 (1, 0, 2);
 498   T3 (1, 1, 0); T3 (1, 1, 1); T3 (1, 1, 2);
 499   T3 (1, 2, 0); T3 (1, 2, 1); T3 (1, 2, 2);
 500
 501   T3 (2, 0, 0); T3 (2, 0, 1); T3 (2, 0, 2);
 502   T3 (2, 1, 0); T3 (2, 1, 1); T3 (2, 1, 2);
 503   T3 (2, 2, 0); T3 (2, 2, 1); T3 (2, 2, 2);
 504 #endif
 505 }
 506
 507 void test_struct_member_flexarray (struct S3 *s3, int i, int j)
 508 {
 509   char *d = s3->fa;
 510   char *s = s3->fa;
 511
 512   T (d, "%s", s);       /* { dg-warning "overlaps" } */
 513   T (d, "%s", s + 0);   /* { dg-warning "overlaps" } */
 514   T (d, "%s", s + 1);   /* { dg-warning "may overlap" } */
 515   T (d, "%s", s + 2);   /* { dg-warning "may overlap" } */
 516   T (d, "%s", s + i);   /* { dg-warning "may overlap" } */
 517
 518   T (d, "%s", &s[0]);   /* { dg-warning "overlaps" } */
 519   T (d, "%s", &s[1]);   /* { dg-warning "may overlap" } */
 520   T (d, "%s", &s[2]);   /* { dg-warning "may overlap" } */
 521   T (d, "%s", &s[i]);   /* { dg-warning "may overlap" } */
 522
 523   T (d + 0, "%s", s);   /* { dg-warning "overlaps" } */
 524   T (d + 1, "%s", s);   /* { dg-warning "may overlap" } */
 525   T (d + 2, "%s", s);   /* { dg-warning "may overlap" } */
 526   T (d + i, "%s", s);   /* { dg-warning "may overlap" } */
 527
 528   T (&d[0], "%s", s);   /* { dg-warning "overlaps" } */
 529   T (&d[1], "%s", s);   /* { dg-warning "may overlap" } */
 530   T (&d[2], "%s", s);   /* { dg-warning "may overlap" } */
 531   T (&d[i], "%s", s);   /* { dg-warning "may overlap" } */
 532
 533   d = s3->fa + i;
 534   s = s3->fa + j;
 535
 536   T (d, "%s", s);       /* { dg-warning "may overlap" } */
 537   T (d, "%s", s + 0);   /* { dg-warning "may overlap" } */
 538   T (d, "%s", s + 1);   /* { dg-warning "may overlap" } */
 539   T (d, "%s", s + 2);   /* { dg-warning "may overlap" } */
 540   T (d, "%s", s + i);   /* { dg-warning "may overlap" } */
 541
 542   T (d, "%s", &s[0]);   /* { dg-warning "may overlap" } */
 543   T (d, "%s", &s[1]);   /* { dg-warning "may overlap" } */
 544   T (d, "%s", &s[2]);   /* { dg-warning "may overlap" } */
 545   T (d, "%s", &s[i]);   /* { dg-warning "may overlap" } */
 546
 547   T (d + 0, "%s", s);   /* { dg-warning "may overlap" } */
 548   T (d + 1, "%s", s);   /* { dg-warning "may overlap" } */
 549   T (d + 2, "%s", s);   /* { dg-warning "may overlap" } */
 550   T (d + j, "%s", s);   /* { dg-warning "may overlap" } */
 551
 552   T (&d[0], "%s", s);   /* { dg-warning "may overlap" } */
 553   T (&d[1], "%s", s);   /* { dg-warning "may overlap" } */
 554   T (&d[2], "%s", s);   /* { dg-warning "may overlap" } */
 555   T (&d[j], "%s", s);   /* { dg-warning "may overlap" } */
 556 }
 557
 558 union U
 559 {
 560   struct S2 s2_1;
 561   struct S2 s2_2;
 562 };
 563
 564 void test_union_member_array (union U *un, int i)
 565 {
 566   char *d = un->s2_1.s_1.a;
 567
 568   T (d, "%s", d);       /* { dg-warning "overlaps" } */
 569   T (d, "%s", d + 0);   /* { dg-warning "overlaps" } */
 570   T (d, "%s", d + 1);   /* { dg-warning "may overlap" } */
 571   T (d, "%s", d + 2);
 572   T (d, "%s", d + i);   /* { dg-warning "may overlap" } */
 573
 574   T (d, "%s", &d[0]);   /* { dg-warning "overlaps" } */
 575   T (d, "%s", &d[1]);   /* { dg-warning "may overlap" } */
 576   T (d, "%s", &d[2]);
 577   T (d, "%s", &d[i]);   /* { dg-warning "may overlap" } */
 578
 579   T (d + 0, "%s", d);   /* { dg-warning "overlaps" } */
 580   T (d + 1, "%s", d);   /* { dg-warning "may overlap" } */
 581   T (d + 2, "%s", d);   /* { dg-warning "may overlap" } */
 582   T (d + i, "%s", d);   /* { dg-warning "may overlap" } */
 583
 584   T (&d[0], "%s", d);   /* { dg-warning "overlaps" } */
 585   T (&d[1], "%s", d);   /* { dg-warning "may overlap" } */
 586   T (&d[2], "%s", d);   /* { dg-warning "may overlap" } */
 587   T (&d[i], "%s", d);   /* { dg-warning "may overlap" } */
 588
 589   const char *s = d;
 590
 591   T (d, "%s", s);       /* { dg-warning "overlaps" } */
 592   T (d, "%s", s + 1);   /* { dg-warning "may overlap" } */
 593   T (d, "%s", s + 2);
 594   T (d, "%s", s + i);   /* { dg-warning "may overlap" } */
 595
 596   s = un->s2_1.s_1.b;
 597
 598   T (d, "%s", s);
 599   T (d, "%s", s + 1);
 600   T (d, "%s", s + 2);
 601   T (d, "%s", s + i);
 602
 603   s = un->s2_1.s_2.a;
 604
 605   T (d, "%s", s);
 606   T (d, "%s", s + 1);
 607   T (d, "%s", s + 2);
 608   T (d, "%s", s + i);
 609
 610   s = un->s2_1.s_2.b;
 611
 612   T (d, "%s", s);
 613   T (d, "%s", s + 1);
 614   T (d, "%s", s + 2);
 615   T (d, "%s", s + i);
 616
 617   s = un->s2_2.s_1.a;
 618
 619   T (d, "%s", s);       /* { dg-warning "overlaps" } */
 620   T (d, "%s", s + 1);   /* { dg-warning "may overlap" } */
 621   T (d, "%s", s + 2);
 622   T (d, "%s", s + i);   /* { dg-warning "may overlap" } */
 623
 624   s = un->s2_2.s_1.b;
 625
 626   T (d, "%s", s);
 627   T (d, "%s", s + 1);
 628   T (d, "%s", s + 2);
 629   T (d, "%s", s + i);
 630 }
 631
 632 void test_multiple_overlap (int i)
 633 {
 634   {
 635     char a[3] = "";           /* { dg-message "declared here" } */
 636
 637     /* Both a3 and a4 definitely overlap the output even if the are
 638        empty because of the terminating nul.  */
 639     char *d = a;
 640     char *a3 = a + 0;
 641     char *a4 = a - 0;
 642
 643     T (d, "%s%s", a3, a4);    /* { dg-warning "arguments 3, 4 overlap destination object .a." }*/
 644   }
 645
 646   {
 647     char a[4];
 648
 649     /* There is no overlap here because the length of a3 is at most 1
 650        and a4 is necessarily the empty string.  */
 651     char *d = a;
 652     char *a3 = a + 2;
 653     char *a4 = a + 3;
 654
 655     T (d, "%s%s", a3, a4);
 656   }
 657
 658   {
 659     char a[5];                /* { dg-message "declared here" } */
 660
 661     /* a3 and a4 may overlap the output.  They will only not overlap
 662        it when a3 is empty, and a4 is at most 1 character long.  */
 663     char *d = a;
 664     char *a3 = a + 2;
 665     char *a4 = a + 3;
 666
 667     T (d, "%s%s", a3, a4);    /* { dg-warning "arguments 3, 4 may overlap destination object .a." }*/
 668   }
 669
 670   {
 671     char a[5];                /* { dg-message "declared here" } */
 672
 673     /* a3 certaibly overlaps the output, but a4 may or may not depending
 674        in the value of i.  */
 675     char *d = a;
 676     char *a3 = a + 0;
 677     char *a4 = a + i;
 678
 679     T (d, "%s%s", a3, a4);    /* { dg-warning "arguments 3 and maybe 4 overlap destination object .a." }*/
 680   }
 681 }
 682
 683 void test_overlap_with_precision (char *d, int i, int j)
 684 {
 685   /* None of the following is diagnosed because no copying takes place
 686      between the %s argument and the destination.  */
 687   T (d, "%.0s", d + 0);
 688   T (d, "%.0s", d + 1);
 689   T (d, "%.0s", d + 2);
 690   T (d, "%.0s", d + i);
 691
 692   T (d, "%.1s", d + 0);       /* { dg-warning "overlaps" } */
 693   /* Unlike the %.0s case the following deserves a warning because
 694      when d[1] isn't nul, it will be overwritten by the terminating
 695      nul added by sprintf.  */
 696   T (d, "%.1s", d + 1);       /* { dg-warning "may overlap" } */
 697   T (d, "%.1s", d + 2);
 698   T (d, "%.1s", d + i);       /* { dg-warning "may overlap" } */
 699
 700   T (d + 1, "%.0s", d);
 701   T (d + 2, "%.0s", d);
 702
 703   T (d + 1, "%.1s", d);       /* { dg-warning "may overlap" } */
 704   T (d + 2, "%.1s", d);
 705
 706   T (d + 2, "%.1s", d + 1);   /* { dg-warning "may overlap" } */
 707   T (d + 2, "%.1s", d + i);   /* { dg-warning "may overlap" } */
 708
 709   /* The following should be "overlaps" but tracking that the offset
 710      is the same variable doesn't seem worth the effort.  */
 711   T (d + i, "%.1s", d + i);   /* { dg-warning "overlap" } */
 712
 713   T (d + i, "%.1s", d + j);   /* { dg-warning "may overlap" } */
 714
 715   /* Exercise overlap with precison in the range [0, 1].  */
 716   if (i < 0 || 1 < i)
 717     i = 0;
 718
 719   T (d, "%.*s", i, d + 0);    /* { dg-warning "may overlap" } */
 720   T (d, "%.*s", i, d + 1);    /* { dg-warning "may overlap" } */
 721   T (d, "%.*s", i, d + 2);
 722   T (d, "%.*s", i, d + i);    /* { dg-warning "may overlap" } */
 723 }