melver wrote: > I'm very excited about this, as I have wanted it for many years for my C > codebase, and TSA is not super useful in C without this!
This PR is being superseded by https://github.com/llvm/llvm-project/pull/127396 (implementation changed completely) - we agreed to go with the more conservative approach, and at the same time also properly handle pt_guarded_by pointers. Wthread-safety-pointer is meant to be to pointer passing what Wthread-safety-reference is to C++ reference passing. I'm leaving this PR up to keep the history. > One thought --- you could consider an attribute that could be put on pointer > arguments to functions that says "yes, I dereference this and read or write > it". In a codebase that otherwise would have many false positives, you could > annotate at least core data structures without having to turn it on for all > address-of operations. > > E.g `void hashtable_insert(htbl_t* WRITES_POINTER table, ...)` > > In the C codebase I desperately want this for, an annotation like that > sprinkled in a couple key places would get you 80% of the benefit with much > lower risk of false positives. Perhaps if there are false positives this can be added. But initially I'd like to avoid it if at all possible. A similar precedent at least for passing references to functions exists with `Wthread-safety-reference` (for C++ references), so in a first iteration we have narrowed it down to effectively mirror Wthread-safety-reference but for pointers. FWIW, something similar to explicit marking can be achieved with something like this (but yes, it's ugly): ``` void __hashtable_insert(htbl_t* table, ...); #define hashtable_insert(table, ...) ({ (void)(*(table)); __hashtable_insert(table, ...); }) ``` Although we might need this patch too, to handle things like `*&var`: https://github.com/llvm/llvm-project/pull/127396/commits/a70f021becb2888d6c2a63b2d1e619393a996058 https://github.com/llvm/llvm-project/pull/123063 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
