[clang] [clang][dataflow] Fix an issue with `Environment::getResultObjectLocation()`. (PR #75483)

[Yitzhak Mandelbaum via cfe-commits]

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@@ -726,27 +726,69 @@ void Environment::setStorageLocation(const Expr &E, StorageLocation &Loc) {
   // so allow these as an exception.
   assert(E.isGLValue() ||
          E.getType()->isSpecificBuiltinType(BuiltinType::BuiltinFn));
-  setStorageLocationInternal(E, Loc);
+  const Expr &CanonE = ignoreCFGOmittedNodes(E);
+  assert(!ExprToLoc.contains(&CanonE));
+  ExprToLoc[&CanonE] = &Loc;
 }
 
 StorageLocation *Environment::getStorageLocation(const Expr &E) const {
   // See comment in `setStorageLocation()`.
   assert(E.isGLValue() ||
          E.getType()->isSpecificBuiltinType(BuiltinType::BuiltinFn));
-  return getStorageLocationInternal(E);
+  auto It = ExprToLoc.find(&ignoreCFGOmittedNodes(E));
+  return It == ExprToLoc.end() ? nullptr : &*It->second;
+}
+
+// Returns whether a prvalue of record type is the one that originally
+// constructs the object (i.e. it doesn't propagate it from one of its
+// children).
+static bool isOriginalRecordConstructor(const Expr &RecordPRValue) {
+  if (auto *Init = dyn_cast<InitListExpr>(&RecordPRValue))
+    return !Init->isSemanticForm() || !Init->isTransparent();
+  return isa<CXXConstructExpr>(RecordPRValue) || isa<CallExpr>(RecordPRValue) ||
+         isa<LambdaExpr>(RecordPRValue) ||
+         // The framework currently does not propagate the objects created in
+         // the two branches of a `ConditionalOperator` because there is no way
+         // to reconcile their storage locations, which are different. We
+         // therefore claim that the `ConditionalOperator` is the expression
+         // that originally constructs the object.
+         // Ultimately, this will be fixed by propagating locations down from
+         // the result object, rather than up from the original constructor as
+         // we do now.
+         isa<ConditionalOperator>(RecordPRValue);
 }
 
 RecordStorageLocation &
-Environment::getResultObjectLocation(const Expr &RecordPRValue) {
+Environment::getResultObjectLocation(const Expr &RecordPRValue) const {
   assert(RecordPRValue.getType()->isRecordType());
   assert(RecordPRValue.isPRValue());
 
-  if (StorageLocation *ExistingLoc = getStorageLocationInternal(RecordPRValue))
-    return *cast<RecordStorageLocation>(ExistingLoc);
-  auto &Loc = cast<RecordStorageLocation>(
-      DACtx->getStableStorageLocation(RecordPRValue));
-  setStorageLocationInternal(RecordPRValue, Loc);
-  return Loc;
+  // Returns a storage location that we can use if assertions fail.
+  auto FallbackForAssertFailure =
+      [this, &RecordPRValue]() -> RecordStorageLocation & {
+    return cast<RecordStorageLocation>(
+        DACtx->getStableStorageLocation(RecordPRValue));
+  };
+
----------------
ymand wrote:

Why the special handling of assertion failures? We don't typically do this, IIUC?

https://github.com/llvm/llvm-project/pull/75483