CBMC contracts crash when dynamic allocation is not in the harness. about cbmc HOT 5 OPEN

I am sorry, I don't understand how to reproduce this. Where can I find that let _ = std::boxed::Box::new(0_usize); that needs to be removed in order to observe the problem?

from cbmc.

Contracts instrumentation attempts to load free from the CPROVER library no matter what the GOTO model contains

CF here:

The contracts instrumentation assumes that if an entry for a library function like free is found in the symbol table then the body of the function is present too, and it doesn't attempt to force-load the function. So the only way contracts would not load the free function into the model is if the symbol table produced by Kani contains an entry for the free function but does not contain the body of the function.

from cbmc.

The output mentioning builtin-library-free suggests it is loaded, so I’m quite confused what is actually going on here. Needs details to reproduce and debug.

from cbmc.

This is an extract of kani_lib.c

// Declare functions instead of importing more headers in order to avoid conflicting definitions.
// See https://github.com/model-checking/kani/issues/1774 for more details.
void  free(void *ptr);
void *memcpy(void *dst, const void *src, size_t n);
void *calloc(size_t nmemb, size_t size);

Could these declarations result in an entry being present for free in the symbol table but the value of the symbol being absent ? or the entry being present but the GOTO function being pruned if its not actually used before contracts instrumentation is applied ?

from cbmc.

file <builtin-library-free> really suggests that we are reading (using?) the definition from CBMC's library, though admittedly this is part of a warning, so it could be that we don't actually link in the implementation. So, still, we need a way to actually reproduce this.

from cbmc.