[CHERI_CSA] AllocationChecker: suppress for free

Author: eupharina

clang/lib/StaticAnalyzer/Checkers/CHERI/AllocationChecker.cpp

@@ -21,6 +21,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
+#include <clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h>
 
 using namespace clang;
 using namespace ento;
@@ -42,6 +43,10 @@ class AllocationChecker
   BugType BT_KnownReg{this, "Heap or static allocation partitioning",
                       "CHERI portability"};
 
+  const CallDescriptionSet IgnoreFnSet = {
+      {{CDM::SimpleFunc, {"free"}, 1}},
+  };
+
   class AllocPartitionBugVisitor : public BugReporterVisitor {
   public:
     AllocPartitionBugVisitor(const MemRegion *P, const MemRegion *A)
@@ -253,6 +258,9 @@ void AllocationChecker::checkPostStmt(const CastExpr *CE,
 
 void AllocationChecker::checkPreCall(const CallEvent &Call,
                                      CheckerContext &C) const {
+  if (IgnoreFnSet.contains(Call))
+    return;
+
   ProgramStateRef State = C.getState();
   ExplodedNode *N = nullptr;
   bool Updated = false;