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// RUN: %clangxx_scudo %s -lstdc++ -o %t
// RUN: %run %t pointers 2>&1
// RUN: %run %t contents 2>&1
// RUN: %run %t usablesize 2>&1
// Tests that our reallocation function returns the same pointer when the
// requested size can fit into the previously allocated chunk. Also tests that
// a new chunk is returned if the size is greater, and that the contents of the
// chunk are left unchanged. Finally, checks that realloc copies the usable
// size of the old chunk to the new one (as opposed to the requested size).
#include <assert.h>
#include <malloc.h>
#include <string.h>
#include <vector>
int main(int argc, char **argv)
{
void *p, *old_p;
// Those sizes will exercise both allocators (Primary & Secondary).
std::vector<size_t> sizes{1, 16, 1024, 32768, 1 << 16, 1 << 17, 1 << 20};
assert(argc == 2);
if (!strcmp(argv[1], "usablesize")) {
// This tests a sketchy behavior inherited from poorly written libraries
// that have become somewhat standard. When realloc'ing a chunk, the
// copied contents should span the usable size of the chunk, not the
// requested size.
size_t size = 496, usable_size;
p = nullptr;
// Make sure we get a chunk with a usable size actually larger than size.
do {
if (p) free(p);
size += 16;
p = malloc(size);
usable_size = malloc_usable_size(p);
assert(usable_size >= size);
} while (usable_size == size);
for (int i = 0; i < usable_size; i++)
reinterpret_cast<char *>(p)[i] = 'A';
old_p = p;
// Make sure we get a different chunk so that the data is actually copied.
do {
size *= 2;
p = realloc(p, size);
assert(p);
} while (p == old_p);
// The contents of the new chunk must match the old one up to usable_size.
for (int i = 0; i < usable_size; i++)
assert(reinterpret_cast<char *>(p)[i] == 'A');
free(p);
} else {
for (size_t size : sizes) {
if (!strcmp(argv[1], "pointers")) {
old_p = p = realloc(nullptr, size);
assert(p);
size = malloc_usable_size(p);
// Our realloc implementation will return the same pointer if the size
// requested is lower than or equal to the usable size of the associated
// chunk.
p = realloc(p, size - 1);
assert(p == old_p);
p = realloc(p, size);
assert(p == old_p);
// And a new one if the size is greater.
p = realloc(p, size + 1);
assert(p != old_p);
// A size of 0 will free the chunk and return nullptr.
p = realloc(p, 0);
assert(!p);
old_p = nullptr;
}
if (!strcmp(argv[1], "contents")) {
p = realloc(nullptr, size);
assert(p);
for (int i = 0; i < size; i++)
reinterpret_cast<char *>(p)[i] = 'A';
p = realloc(p, size + 1);
// The contents of the reallocated chunk must match the original one.
for (int i = 0; i < size; i++)
assert(reinterpret_cast<char *>(p)[i] == 'A');
}
}
}
return 0;
}
// CHECK: ERROR: invalid chunk type when reallocating address
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