[clang] [clang][dataflow] Rewrite `getReferencedDecls()` with a `RecursiveASTVisitor`. (PR #93461)

[Yitzhak Mandelbaum via cfe-commits]

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@@ -188,90 +188,97 @@ static MemberExpr *getMemberForAccessor(const CXXMemberCallExpr &C) {
   return nullptr;
 }
 
-static void getReferencedDecls(const Decl &D, ReferencedDecls &Referenced) {
-  insertIfGlobal(D, Referenced.Globals);
-  insertIfFunction(D, Referenced.Functions);
-  if (const auto *Decomp = dyn_cast<DecompositionDecl>(&D))
-    for (const auto *B : Decomp->bindings())
-      if (auto *ME = dyn_cast_or_null<MemberExpr>(B->getBinding()))
-        // FIXME: should we be using `E->getFoundDecl()`?
-        if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
-          Referenced.Fields.insert(FD);
-}
+class ReferencedDeclsVisitor
+    : public AnalysisASTVisitor<ReferencedDeclsVisitor> {
+public:
+  ReferencedDeclsVisitor(ReferencedDecls &Referenced)
+      : Referenced(Referenced) {}
+
+  void TraverseConstructorInits(const CXXConstructorDecl *Ctor) {
+    for (const CXXCtorInitializer *Init : Ctor->inits()) {
+      if (Init->isMemberInitializer()) {
+        Referenced.Fields.insert(Init->getMember());
+      } else if (Init->isIndirectMemberInitializer()) {
+        for (const auto *I : Init->getIndirectMember()->chain())
+          Referenced.Fields.insert(cast<FieldDecl>(I));
+      }
+
+      Expr *InitExpr = Init->getInit();
+
+      // Ensure that any result objects within `InitExpr` (e.g. temporaries)
+      // are also propagated to the prvalues that initialize them.
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ymand wrote:

Here and below: this comment seems out of place for this visitor -- it's just collecting names, not doing any propagating (I thought)?

https://github.com/llvm/llvm-project/pull/93461