mirror of
https://github.com/Zenithsiz/ftmemsim-valgrind.git
synced 2026-02-03 01:51:29 +00:00
50bded71b2
Adds a new warning to memcheck when realloc is used with a size of 0. For a long time this has been "implementation defined" and so non-portable. With C23 it will become UB. Also adds a switch to turn off the error generation and a second switch to select between the most common "implementation" behaviours. The defaults for this second switch are baked in at build time.
42 lines
841 B
C++
42 lines
841 B
C++
#include <iostream>
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#include <cstdlib>
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#include <cerrno>
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using std::realloc;
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using std::cout;
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using std::perror;
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int main(void)
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{
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char* p = new char[1024];
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p[0] = '\0';
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errno = 0;
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// mismatch
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p = static_cast<char *>(realloc(p, 0));
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if (p) {
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cout << "p not nullptr after realloc 0\n";
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} else {
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cout << "p is nullptr after realloc 0\n";
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}
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if (errno) {
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perror("realloc(something, 0):");
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}
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// mismatch again
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delete [] p;
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errno = 0;
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volatile void *ptr = NULL;
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volatile size_t size = 0U;
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char *p2 = static_cast<char *>(realloc(const_cast<void*>(ptr), size));
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if (p2) {
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cout << "p2 not nullptr after realloc 0\n";
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} else {
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cout << "p2 is nullptr after realloc 0\n";
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}
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if (errno) {
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perror("realloc(NULL, 0):");
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}
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// mismatch
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delete [] p2;
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}
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