[clang] [LifetimeSafety] Trace assignment history for use-after-scope errors (PR #188467)

[Gábor Horváth via cfe-commits]

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@@ -0,0 +1,72 @@
+//===- AssignmentQuery.cpp - C++ Lifetime Safety Checker --------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the LifetimeChecker, which detects use-after-free
+// errors by checking if live origins hold loans that have expired.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_ANALYSIS_ANALYSES_ASSIGNMENTQUERY_H
+#define LLVM_CLANG_ANALYSIS_ANALYSES_ASSIGNMENTQUERY_H
+
+#include "clang/AST/Decl.h"
+#include "clang/Analysis/Analyses/LifetimeSafety/Facts.h"
+#include "clang/Analysis/Analyses/LifetimeSafety/LiveOrigins.h"
+#include "clang/Analysis/Analyses/LifetimeSafety/LoanPropagation.h"
+#include "clang/Analysis/Analyses/LifetimeSafety/MovedLoans.h"
+#include "clang/Analysis/Analyses/LifetimeSafety/Origins.h"
+#include "clang/Analysis/AnalysisDeclContext.h"
+
+namespace clang::lifetimes {
+
+using OriginDestExpr =
+    llvm::PointerUnion<const DeclRefExpr *, const ValueDecl *,
+                       const MemberExpr *>;
+using LoanEntity = llvm::PointerUnion<const Expr *, const ParmVarDecl *,
+                                      const CXXMethodDecl *>;
+
+using AssignmentPair = std::pair<OriginDestExpr, const Expr *>;
+
+struct ExprPrintingResult {
+  llvm::StringRef Str;
+  const Expr *CurrExpr;
+};
+
+void FormatLoanEntityForSema(LoanEntity IssueEntity,
+                             llvm::SmallVectorImpl<char> &IssueMsg);
+void FormatSrcExprForSema(
+    const Expr *SrcExpr, llvm::SmallVectorImpl<ExprPrintingResult> &SrcMsgList);
+} // namespace clang::lifetimes
+
+namespace clang::lifetimes::internal {
+
+struct AliasAssignmentSearchResult {
+  bool SearchComplete;
+  const std::optional<OriginDestExpr> LastDestDecl;
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Xazax-hun wrote:

Is the `const` intentional here?

https://github.com/llvm/llvm-project/pull/188467