https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107534
Bug ID: 107534
Summary: Analyzer should flag shallow copies of resources
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: analyzer
Assignee: dmalcolm at gcc dot gnu.org
Reporter: redi at gcc dot gnu.org
Blocks: 97110
Target Milestone: ---
As shown in PR 94355 comment 11, this code reports a use-after-free (and a
spurious leak and spurious null deref):
struct S {
S() { p = new int(); }
~S() { delete p; }
int* p = nullptr;
};
int main() {
S s;
S ss = s;
}
Ideally the copy construction of 'ss' would flag that we end up with two owners
of the heap pointer. The new object should either make a deep copy (allocate a
new object as a copy of *s.p) or should clear the source so it's left empty
(which would require a move constructor, not just the trivial copy constructor
that makes the shallow copy here).
In other words, rather than flagging three symptoms, flag the cause. The type
manages dynamic resources but doesn't have a user-provided copy or move
constructor and so manages them unsafely.
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97110
[Bug 97110] [meta-bug] tracker bug for supporting C++ in -fanalyzer
