NoQ added a comment.
I don't think you actually need active support for invoking exit handlers
path-sensitively at the end of `main()` in order to implement your checker. You
can still find out in a path-insensitive manner whether any given function acts
as an exit handler, like you already do. Then during path-sensitive analysis of
that function you can warn at any invocation of exit().
I do believe that you want to implement this check as a path-sensitive check as
long as you want any sort of interprocedural analysis (i.e., warn when an exit
handler calls a function that calls a function ... that calls a function that
calls `exit()` - and you do already have such tests). This is because of the
following potential situation:
void foo(bool already_exiting) {
if (!already_exiting)
exit();
}
void bar() {
foo(true);
}
void baz() {
foo(false);
}
int main() {
atexit(bar);
return 0;
}
In this case `bar()` is an exit handler that calls `foo()` that calls `exit()`.
However the code is correct and no warning should be emitted, because `foo()`
would never call `exit()` //when called from// `bar()` //specifically//.
Precise reasoning about such problems requires path-sensitive analysis. Of
course it's up to you to decide what to do with these false positives - whether
you'll be ok with having them, or choose to suppress with an imprecise
heuristic - but that's one of the possible reasons to consider reimplementing
the checker via path sensitive analysis that the static analyzer provides.
We've had a similar problem with the checker that warns on calling pure virtual
functions in constructors/destructors (which is undefined behavior). Such
checker had to be path sensitive in order to be interprocedural for the exact
same unobvious reason. We've decided to re-implement it with path-sensitive
analysis and now we're pretty happy about that decision.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D83717/new/
https://reviews.llvm.org/D83717
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