[clang] [LifetimeSafety] Introduce buildOriginFlowChain for use-after-scope (PR #199345)

[Utkarsh Saxena via cfe-commits]

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@@ -54,14 +54,24 @@ inline bool IsLifetimeSafetyEnabled(Sema &S, const Decl *D) {
   return false;
 }
 
+inline StringRef formatExpr(const Expr *E) {
+  const Expr *PureExpr = E->IgnoreImpCasts();
+  if (const DeclRefExpr *DRExpr = dyn_cast<DeclRefExpr>(PureExpr))
+    return DRExpr->getDecl()->getName();
+
+  // TODO: Add support for more expression types.
+  return "";
+}
+
 class LifetimeSafetySemaHelperImpl : public LifetimeSafetySemaHelper {
 
 public:
   LifetimeSafetySemaHelperImpl(Sema &S) : S(S) {}
 
-  void reportUseAfterScope(const Expr *IssueExpr, const Expr *UseExpr,
-                           const Expr *MovedExpr,
-                           SourceLocation FreeLoc) override {
+  void reportUseAfterScope(
+      const Expr *IssueExpr, const Expr *UseExpr, const Expr *MovedExpr,
+      SourceLocation FreeLoc,
+      llvm::SmallVector<const Expr *> OriginExprChain) override {
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usx95 wrote:

Use `llvm::ArrayRef<const Expr *>` to avoid copying this.

https://github.com/llvm/llvm-project/pull/199345