Summary: @public Infer previously did not work correctly when a function returns the result of a skip function:
```
retUndef() {
x = undefined();
return x;
}
derefUndef() {
y = retUndef();
y.doSomething(); // Symexec_memory_error here, prevents spec inference
}
```
The problem is that angelic mode did not know to add the return value of `retUndef()` to the footprint.
This diff fixes the problem by adding return values marked with the `Aundef` attribute to the footprint.
This is done lazily (e.g., a value only gets added to the footprint when you try to deref it).
Reviewed By: @jvillard
Differential Revision: D2444929
Summary:
`get_resource_or_undef` attribute is weird and was causing problems for me in another diff.
This diff refactors the attribute categories to make resource and undef separate.
Summary:
There's a lot of overlap between the representation of a proc desc and a spec summary. This diff moves all the data in common to the single record proc_attributes defined in Sil.
This gives a unified way of accessing most of the data carried by a procedure, whether it is contained in a proc desc or a spec. Also, it ensures that there is a single flow of information from proc desc to spec in the back-end, making sure that the information represented stays consistent.
Summary:
The symbolic execution was not stopping in case an unitialized dangling pointer was
passed to a function and then dereferenced inside the callee.
What would happen is that a wrong footprint would be added to the unititialized pointer
at the end of the function call in the caller proposition.
This checks that if we do:
frame * new_footprint
checks that we do not add heap predicates to the frame into uninitialized local variables.
If we can identify the variable then we raise a danglind pointer dereference. If instead
we cannot give a good explanation we give an internal error.
The latter case should be temporary. We should find a general way to raise dangling pointer
deref instead of the internal error.
I also fixed the model of getc that was the way I found the problem.
Summary:
This commit is the result of
`find infer/src -name '*.ml' -or -name '*.mli' -exec ocp-indent -i \{\} \;`
and
`INFER_CHECK_COPYRIGHT=1 InferPrint`
Summary:
the name of the return variable of a procedure only depends on the name of that procedure. This simplifies the need for the procedure description in a couple of places