[clang] [analyzer] Add aggregate value tracking to the LifetimeModeling checker (PR #214823)

[Benedek Kaibas via cfe-commits]

================
@@ -105,6 +105,68 @@ std::string lifetime_modeling::getRegionName(const MemRegion *Reg) {
   return "the region";
 }
 
+namespace clang::ento::lifetime_modeling {
+
+static SmallVector<const MemRegion *, 4>
+getRegionsFromAggrVal(nonloc::LazyCompoundVal LCV, CheckerContext &C) {
+  SmallVector<const MemRegion *, 4> Reg;
+
+  const TypedValueRegion *LCVRegion = LCV.getRegion();
+  QualType T = LCVRegion->getValueType();
+  MemRegionManager &MemMgr = C.getSValBuilder().getRegionManager();
+  StoreManager &StoreMgr = C.getState()->getStateManager().getStoreManager();
+
+  // FIXME: getAsRecordDecl() also includes unions which need different
+  // handling. Reading a binding for every member of a union may produce regions
+  // that are not actually live.
+  if (const RecordDecl *RD = T->getAsRecordDecl()) {
----------------
benedekaibas wrote:

Array aggregates are not yet handled since `getAsRecordDecl` returns null in case of array aggregates. There is already a `FIXME` comment in the test file for the array field case. I have also added a FIXME comment in the function body, in this commit: [24bf85a](https://github.com/llvm/llvm-project/pull/214823/commits/24bf85a76ad73ec791534259fa4d7ebb5b0cc9bb)

https://github.com/llvm/llvm-project/pull/214823