Revert "[LifetimeSafety] Reorganize code into modular components (llvm#162474)"

This reverts commit 2eb8c47 since it completely breaks dylib build.

Author: shiltian

.github/new-prs-labeler.yml

@@ -1096,8 +1096,8 @@ clang:openmp:
   - llvm/test/Transforms/OpenMP/**
 
 clang:temporal-safety:
-  - clang/include/clang/Analysis/Analyses/LifetimeSafety/**
-  - clang/lib/Analysis/LifetimeSafety/**
+  - clang/include/clang/Analysis/Analyses/LifetimeSafety*
+  - clang/lib/Analysis/LifetimeSafety*
   - clang/unittests/Analysis/LifetimeSafety*
   - clang/test/Sema/*lifetime-safety*
   - clang/test/Sema/*lifetime-analysis*

clang/include/clang/Analysis/Analyses/LifetimeSafety/LifetimeAnnotations.h renamed to clang/include/clang/Analysis/Analyses/LifetimeAnnotations.h

@@ -12,7 +12,8 @@
 
 #include "clang/AST/DeclCXX.h"
 
-namespace clang ::lifetimes {
+namespace clang {
+namespace lifetimes {
 
 /// Returns the most recent declaration of the method to ensure all
 /// lifetime-bound attributes from redeclarations are considered.
@@ -37,7 +38,7 @@ bool isAssignmentOperatorLifetimeBound(const CXXMethodDecl *CMD);
 /// lifetimebound, either due to an explicit lifetimebound attribute on the
 /// method or because it's a normal assignment operator.
 bool implicitObjectParamIsLifetimeBound(const FunctionDecl *FD);
-
-} // namespace clang::lifetimes
+} // namespace lifetimes
+} // namespace clang
 
 #endif // LLVM_CLANG_ANALYSIS_ANALYSES_LIFETIMEANNOTATIONS_H

clang/include/clang/Analysis/Analyses/LifetimeSafety.h

@@ -0,0 +1,183 @@
+//===- LifetimeSafety.h - C++ Lifetime Safety Analysis -*----------- 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 defines the entry point for a dataflow-based static analysis
+// that checks for C++ lifetime violations.
+//
+// The analysis is based on the concepts of "origins" and "loans" to track
+// pointer lifetimes and detect issues like use-after-free and dangling
+// pointers. See the RFC for more details:
+// https://discourse.llvm.org/t/rfc-intra-procedural-lifetime-analysis-in-clang/86291
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_CLANG_ANALYSIS_ANALYSES_LIFETIMESAFETY_H
+#define LLVM_CLANG_ANALYSIS_ANALYSES_LIFETIMESAFETY_H
+#include "clang/Analysis/AnalysisDeclContext.h"
+#include "clang/Analysis/CFG.h"
+#include "clang/Basic/SourceLocation.h"
+#include "llvm/ADT/DenseMapInfo.h"
+#include "llvm/ADT/ImmutableMap.h"
+#include "llvm/ADT/ImmutableSet.h"
+#include "llvm/ADT/StringMap.h"
+#include <memory>
+
+namespace clang::lifetimes {
+
+/// Enum to track the confidence level of a potential error.
+enum class Confidence : uint8_t {
+  None,
+  Maybe,   // Reported as a potential error (-Wlifetime-safety-strict)
+  Definite // Reported as a definite error (-Wlifetime-safety-permissive)
+};
+
+enum class LivenessKind : uint8_t {
+  Dead,  // Not alive
+  Maybe, // Live on some path but not all paths (may-be-live)
+  Must   // Live on all paths (must-be-live)
+};
+
+class LifetimeSafetyReporter {
+public:
+  LifetimeSafetyReporter() = default;
+  virtual ~LifetimeSafetyReporter() = default;
+
+  virtual void reportUseAfterFree(const Expr *IssueExpr, const Expr *UseExpr,
+                                  SourceLocation FreeLoc,
+                                  Confidence Confidence) {}
+};
+
+/// The main entry point for the analysis.
+void runLifetimeSafetyAnalysis(AnalysisDeclContext &AC,
+                               LifetimeSafetyReporter *Reporter);
+
+namespace internal {
+// Forward declarations of internal types.
+class Fact;
+class FactManager;
+class LoanPropagationAnalysis;
+class ExpiredLoansAnalysis;
+class LiveOriginAnalysis;
+struct LifetimeFactory;
+
+/// A generic, type-safe wrapper for an ID, distinguished by its `Tag` type.
+/// Used for giving ID to loans and origins.
+template <typename Tag> struct ID {
+  uint32_t Value = 0;
+
+  bool operator==(const ID<Tag> &Other) const { return Value == Other.Value; }
+  bool operator!=(const ID<Tag> &Other) const { return !(*this == Other); }
+  bool operator<(const ID<Tag> &Other) const { return Value < Other.Value; }
+  ID<Tag> operator++(int) {
+    ID<Tag> Tmp = *this;
+    ++Value;
+    return Tmp;
+  }
+  void Profile(llvm::FoldingSetNodeID &IDBuilder) const {
+    IDBuilder.AddInteger(Value);
+  }
+};
+
+using LoanID = ID<struct LoanTag>;
+using OriginID = ID<struct OriginTag>;
+inline llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, LoanID ID) {
+  return OS << ID.Value;
+}
+inline llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, OriginID ID) {
+  return OS << ID.Value;
+}
+
+// Using LLVM's immutable collections is efficient for dataflow analysis
+// as it avoids deep copies during state transitions.
+// TODO(opt): Consider using a bitset to represent the set of loans.
+using LoanSet = llvm::ImmutableSet<LoanID>;
+using OriginSet = llvm::ImmutableSet<OriginID>;
+using OriginLoanMap = llvm::ImmutableMap<OriginID, LoanSet>;
+
+/// A `ProgramPoint` identifies a location in the CFG by pointing to a specific
+/// `Fact`. identified by a lifetime-related event (`Fact`).
+///
+/// A `ProgramPoint` has "after" semantics: it represents the location
+/// immediately after its corresponding `Fact`.
+using ProgramPoint = const Fact *;
+
+/// Running the lifetime safety analysis and querying its results. It
+/// encapsulates the various dataflow analyses.
+class LifetimeSafetyAnalysis {
+public:
+  LifetimeSafetyAnalysis(AnalysisDeclContext &AC,
+                         LifetimeSafetyReporter *Reporter);
+  ~LifetimeSafetyAnalysis();
+
+  void run();
+
+  /// Returns the set of loans an origin holds at a specific program point.
+  LoanSet getLoansAtPoint(OriginID OID, ProgramPoint PP) const;
+
+  /// Returns the set of origins that are live at a specific program point,
+  /// along with the confidence level of their liveness.
+  ///
+  /// An origin is considered live if there are potential future uses of that
+  /// origin after the given program point. The confidence level indicates
+  /// whether the origin is definitely live (Definite) due to being domintated
+  /// by a set of uses or only possibly live (Maybe) only on some but not all
+  /// control flow paths.
+  std::vector<std::pair<OriginID, LivenessKind>>
+  getLiveOriginsAtPoint(ProgramPoint PP) const;
+
+  /// Finds the OriginID for a given declaration.
+  /// Returns a null optional if not found.
+  std::optional<OriginID> getOriginIDForDecl(const ValueDecl *D) const;
+
+  /// Finds the LoanID's for the loan created with the specific variable as
+  /// their Path.
+  std::vector<LoanID> getLoanIDForVar(const VarDecl *VD) const;
+
+  /// Retrieves program points that were specially marked in the source code
+  /// for testing.
+  ///
+  /// The analysis recognizes special function calls of the form
+  /// `void("__lifetime_test_point_<name>")` as test points. This method returns
+  /// a map from the annotation string (<name>) to the corresponding
+  /// `ProgramPoint`. This allows test harnesses to query the analysis state at
+  /// user-defined locations in the code.
+  /// \note This is intended for testing only.
+  llvm::StringMap<ProgramPoint> getTestPoints() const;
+
+private:
+  AnalysisDeclContext &AC;
+  LifetimeSafetyReporter *Reporter;
+  std::unique_ptr<LifetimeFactory> Factory;
+  std::unique_ptr<FactManager> FactMgr;
+  std::unique_ptr<LoanPropagationAnalysis> LoanPropagation;
+  std::unique_ptr<LiveOriginAnalysis> LiveOrigins;
+};
+} // namespace internal
+} // namespace clang::lifetimes
+
+namespace llvm {
+template <typename Tag>
+struct DenseMapInfo<clang::lifetimes::internal::ID<Tag>> {
+  using ID = clang::lifetimes::internal::ID<Tag>;
+
+  static inline ID getEmptyKey() {
+    return {DenseMapInfo<uint32_t>::getEmptyKey()};
+  }
+
+  static inline ID getTombstoneKey() {
+    return {DenseMapInfo<uint32_t>::getTombstoneKey()};
+  }
+
+  static unsigned getHashValue(const ID &Val) {
+    return DenseMapInfo<uint32_t>::getHashValue(Val.Value);
+  }
+
+  static bool isEqual(const ID &LHS, const ID &RHS) { return LHS == RHS; }
+};
+} // namespace llvm
+
+#endif // LLVM_CLANG_ANALYSIS_ANALYSES_LIFETIMESAFETY_H