[PATCH] D152504: [clang][ThreadSafety] Analyze cleanup functions

[Timm Bäder via Phabricator via cfe-commits]

tbaeder added inline comments.


================
Comment at: clang/lib/Analysis/ThreadSafety.cpp:2436
+                                    CF.getVarDecl()->getLocation());
+          break;
+        }
----------------
tbaeder wrote:
> tbaeder wrote:
> > aaronpuchert wrote:
> > > aaronpuchert wrote:
> > > > tbaeder wrote:
> > > > > This handles the function call, but without the instance parameter. I was wondering how to best do that.
> > > > Should you not simply pass `SxBuilder.createVariable(CF.getVarDecl())` as third parameter in analogy with the `AutomaticObjectDtor` case? It might also make sense to copy the attribute check.
> > > Can you write a test case that relies on passing the variable? Here is an idea:
> > > ```
> > > void unlock_scope(Mutex **mu) __attribute__((release_capability(*mu))) {
> > >   mutex_exclusive_unlock(*mu);
> > > }
> > > 
> > > Mutex* const CLEANUP(unlock_scope) scope = &mu1;
> > > mutex_exclusive_lock(*scope);
> > > // Unlock should happen automatically.
> > > ```
> > > I think this is mildly more interesting than the cleanup function with an unused parameter.
> > > 
> > > Unfortunately this is not quite as powerful as a scoped lock in C++, as we don't track the identity `scope == &mu1`. So `guarded_by` won't work with this. But we can at least see warnings on balanced locking/unlocking.
> > > 
> > > As for proper scoped locking, we could treat some variable initializations like construction of a C++ scoped lock. But let's discuss this separately.
> > Yeah, it doesn't find the lock; I assume that's because the first parameter here is not an _actual_ this parameter; I'd have to handle the var decl as a regular parameter.
> @aaronpuchert Can you explain how that would work? One goal from before was to avoid creating new fake AST nodes, would I'd have to insert the instance parameter as a new `DeclRefExpr` in the CFG, wouldn't I?
Ping


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D152504/new/

https://reviews.llvm.org/D152504