src/libcompiler_builtins/compiler-rt/test/scudo/realloc.cpp

   1 // RUN: %clangxx_scudo %s -lstdc++ -o %t
   2 // RUN: %run %t pointers 2>&1
   3 // RUN: %run %t contents 2>&1
   4 // RUN: %run %t usablesize 2>&1
   5
   6 // Tests that our reallocation function returns the same pointer when the
   7 // requested size can fit into the previously allocated chunk. Also tests that
   8 // a new chunk is returned if the size is greater, and that the contents of the
   9 // chunk are left unchanged. Finally, checks that realloc copies the usable
  10 // size of the old chunk to the new one (as opposed to the requested size).
  11
  12 #include <assert.h>
  13 #include <malloc.h>
  14 #include <string.h>
  15
  16 #include <vector>
  17
  18 int main(int argc, char **argv)
  19 {
  20   void *p, *old_p;
  21   // Those sizes will exercise both allocators (Primary & Secondary).
  22   std::vector<size_t> sizes{1, 16, 1024, 32768, 1 << 16, 1 << 17, 1 << 20};
  23
  24   assert(argc == 2);
  25
  26   if (!strcmp(argv[1], "usablesize")) {
  27     // This tests a sketchy behavior inherited from poorly written libraries
  28     // that have become somewhat standard. When realloc'ing a chunk, the
  29     // copied contents should span the usable size of the chunk, not the
  30     // requested size.
  31     size_t size = 496, usable_size;
  32     p = nullptr;
  33     // Make sure we get a chunk with a usable size actually larger than size.
  34     do {
  35       if (p) free(p);
  36       size += 16;
  37       p = malloc(size);
  38       usable_size = malloc_usable_size(p);
  39       assert(usable_size >= size);
  40     } while (usable_size == size);
  41     for (int i = 0; i < usable_size; i++)
  42       reinterpret_cast<char *>(p)[i] = 'A';
  43     old_p = p;
  44     // Make sure we get a different chunk so that the data is actually copied.
  45     do {
  46       size *= 2;
  47       p = realloc(p, size);
  48       assert(p);
  49     } while (p == old_p);
  50     // The contents of the new chunk must match the old one up to usable_size.
  51     for (int i = 0; i < usable_size; i++)
  52       assert(reinterpret_cast<char *>(p)[i] == 'A');
  53     free(p);
  54   } else {
  55     for (size_t size : sizes) {
  56       if (!strcmp(argv[1], "pointers")) {
  57         old_p = p = realloc(nullptr, size);
  58         assert(p);
  59         size = malloc_usable_size(p);
  60         // Our realloc implementation will return the same pointer if the size
  61         // requested is lower than or equal to the usable size of the associated
  62         // chunk.
  63         p = realloc(p, size - 1);
  64         assert(p == old_p);
  65         p = realloc(p, size);
  66         assert(p == old_p);
  67         // And a new one if the size is greater.
  68         p = realloc(p, size + 1);
  69         assert(p != old_p);
  70         // A size of 0 will free the chunk and return nullptr.
  71         p = realloc(p, 0);
  72         assert(!p);
  73         old_p = nullptr;
  74       }
  75       if (!strcmp(argv[1], "contents")) {
  76         p = realloc(nullptr, size);
  77         assert(p);
  78         for (int i = 0; i < size; i++)
  79           reinterpret_cast<char *>(p)[i] = 'A';
  80         p = realloc(p, size + 1);
  81         // The contents of the reallocated chunk must match the original one.
  82         for (int i = 0; i < size; i++)
  83           assert(reinterpret_cast<char *>(p)[i] == 'A');
  84       }
  85     }
  86   }
  87   return 0;
  88 }
  89
  90 // CHECK: ERROR: invalid chunk type when reallocating address