[PATCH] D137348: -Wunsafe-buffer-usage: Introduce an abstraction for fixable code patterns.

[Artem Dergachev via Phabricator via cfe-commits]

NoQ created this revision.
NoQ added reviewers: aaron.ballman, gribozavr2, xazax.hun, jkorous, t-rasmud, ziqingluo-90, malavikasamak.
Herald added subscribers: steakhal, martong, rnkovacs.
Herald added a project: All.
NoQ requested review of this revision.

This patch introduces a hierarchy of `Gadget` classes, which are going to be the core concept in our fixit machine.

A //gadget// is a rigid code pattern that constitutes an operation that the fixit machine "understands" well enough to work with. A gadget may be "unsafe" (i.e., constitute a raw buffer access) or "safe" (constitute a use of a pointer or array variable that isn't unsafe per se, but may need fixing if the participating variable changes type to a safe container/view).

By "rigid" I mean something like "matchable with a sequence of nested if-dyncast-statements or an ASTMatcher without `forEachDescendant()` or other non-trivial traversal, except maybe `ignoringParenImpCasts()` and such. The point is to make it very clear what the semantics of that code is.

We'll be able to make decisions about how to fix the code depending on the set of gadgets that we've enumerated. Basically, in order to fix a type of a variable, each use of that variable has to participate in a gadget, and each such gadget has to consent to fixing itself according to the variable's new type. More on that in follow-up patches!


Repository:
  rC Clang

https://reviews.llvm.org/D137348

Files:
  clang/include/clang/Analysis/Analyses/UnsafeBufferUsageGadgets.def
  clang/lib/Analysis/UnsafeBufferUsage.cpp

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D137348.472990.patch
Type: text/x-patch
Size: 9079 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20221103/25504f4d/attachment-0001.bin>