[clang] [analyzer] Modernize, improve and promote chroot checker (PR #117791)

[via cfe-commits]

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@@ -104,15 +146,35 @@ void ChrootChecker::evalChdir(const CallEvent &Call, CheckerContext &C) const {
     R = R->StripCasts();
     if (const StringRegion* StrRegion= dyn_cast<StringRegion>(R)) {
       const StringLiteral* Str = StrRegion->getStringLiteral();
-      if (Str->getString() == "/")
-        state = Mgr.addGDM(state, ChrootChecker::getTag(),
-                           (void*) JAIL_ENTERED);
+      if (Str->getString() == "/") {
+        state = state->set<ChrootState>(JAIL_ENTERED);
+      }
     }
   }
 
   C.addTransition(state);
 }
 
+const ExplodedNode *ChrootChecker::getAcquisitionSite(const ExplodedNode *N,
+                                                      CheckerContext &C) {
+  ProgramStateRef State = N->getState();
+  // When bug type is resource leak, exploded node N may not have state info
+  // for leaked file descriptor, but predecessor should have it.
+  if (!State->get<ChrootCall>())
+    N = N->getFirstPred();
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vabridgers wrote:

Your comments have inspired different thoughts about how to address the problem I'm wanting to solve. Basically, when the checker detects an unexpected use of chdir() I need information about where chroot() was use prior for a detailed and useful warning message. You probably recognize, but I reused design/use patterns from the stream checker that seemed close to what I want. The solution can evolve of course. Thanks for your comments.

https://github.com/llvm/llvm-project/pull/117791