[analyzer][NFC] Introduce APSIntPtr, a safe wrapper of APSInt (1/4)

steakhal · steakhal · commit eddf348e1e1b · 2024-12-18T16:13:16.000+01:00
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/APSIntPtr.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/APSIntPtr.h
@@ -0,0 +1,64 @@
+//== APSIntPtr.h - Wrapper for APSInt objects owned separately -*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_APSIntPtr_H
+#define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_APSIntPtr_H
+
+#include "llvm/ADT/APSInt.h"
+
+namespace clang::ento {
+class BasicValueFactory;
+
+/// A safe wrapper around APSInt objects allocated and owned by
+/// \c BasicValueFactory. This just wraps a common llvm::APSInt.
+class APSIntPtr {
+  using APSInt = llvm::APSInt;
+
+public:
+  APSIntPtr() = delete;
+  APSIntPtr(const APSIntPtr &) = default;
+  APSIntPtr &operator=(const APSIntPtr &) & = default;
+  ~APSIntPtr() = default;
+
+  /// You should not use this API.
+  /// If do, ensure that the \p Ptr not going to dangle.
+  /// Prefer using \c BasicValueFactory::getValue() to get an APSIntPtr object.
+  static APSIntPtr unsafeConstructor(const APSInt *Ptr) {
+    return APSIntPtr(Ptr);
+  }
+
+  const APSInt *get() const { return Ptr; }
+  /*implicit*/ operator const APSInt &() const { return *get(); }
+
+  APSInt operator-() const { return -*Ptr; }
+  APSInt operator~() const { return ~*Ptr; }
+
+#define DEFINE_OPERATOR(OP)                                                    \
+  bool operator OP(APSIntPtr Other) const { return (*Ptr)OP(*Other.Ptr); }
+  DEFINE_OPERATOR(>)
+  DEFINE_OPERATOR(>=)
+  DEFINE_OPERATOR(<)
+  DEFINE_OPERATOR(<=)
+  DEFINE_OPERATOR(==)
+  DEFINE_OPERATOR(!=)
+#undef DEFINE_OPERATOR
+
+  const APSInt &operator*() const { return *Ptr; }
+  const APSInt *operator->() const { return Ptr; }
+
+private:
+  friend class BasicValueFactory;
+  explicit APSIntPtr(const APSInt *Ptr) : Ptr(Ptr) {}
+
+  /// Owned by \c BasicValueFactory.
+  const APSInt *Ptr;
+};
+
+} // namespace clang::ento
+
+#endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_APSIntPtr_H
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h
@@ -18,10 +18,11 @@
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/Type.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/APSIntPtr.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/APSIntType.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/StoreRef.h"
-#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
 #include "llvm/ADT/APSInt.h"
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/ImmutableList.h"
@@ -129,7 +130,7 @@ class BasicValueFactory {
 
   // This is private because external clients should use the factory
   // method that takes a QualType.
-  const llvm::APSInt& getValue(uint64_t X, unsigned BitWidth, bool isUnsigned);
+  APSIntPtr getValue(uint64_t X, unsigned BitWidth, bool isUnsigned);
 
 public:
   BasicValueFactory(ASTContext &ctx, llvm::BumpPtrAllocator &Alloc)
@@ -140,9 +141,9 @@ class BasicValueFactory {
 
   ASTContext &getContext() const { return Ctx; }
 
-  const llvm::APSInt& getValue(const llvm::APSInt& X);
-  const llvm::APSInt& getValue(const llvm::APInt& X, bool isUnsigned);
-  const llvm::APSInt& getValue(uint64_t X, QualType T);
+  APSIntPtr getValue(const llvm::APSInt &X);
+  APSIntPtr getValue(const llvm::APInt &X, bool isUnsigned);
+  APSIntPtr getValue(uint64_t X, QualType T);
 
   /// Returns the type of the APSInt used to store values of the given QualType.
   APSIntType getAPSIntType(QualType T) const {
@@ -165,79 +166,70 @@ class BasicValueFactory {
 
   /// Convert - Create a new persistent APSInt with the same value as 'From'
   ///  but with the bitwidth and signedness of 'To'.
-  const llvm::APSInt &Convert(const llvm::APSInt& To,
-                              const llvm::APSInt& From) {
+  APSIntPtr Convert(const llvm::APSInt &To, const llvm::APSInt &From) {
     APSIntType TargetType(To);
     if (TargetType == APSIntType(From))
-      return From;
+      return APSIntPtr(&From);
 
     return getValue(TargetType.convert(From));
   }
 
-  const llvm::APSInt &Convert(QualType T, const llvm::APSInt &From) {
+  APSIntPtr Convert(QualType T, const llvm::APSInt &From) {
     APSIntType TargetType = getAPSIntType(T);
     return Convert(TargetType, From);
   }
 
-  const llvm::APSInt &Convert(APSIntType TargetType, const llvm::APSInt &From) {
+  APSIntPtr Convert(APSIntType TargetType, const llvm::APSInt &From) {
     if (TargetType == APSIntType(From))
-      return From;
+      return APSIntPtr(&From);
 
     return getValue(TargetType.convert(From));
   }
 
-  const llvm::APSInt &getIntValue(uint64_t X, bool isUnsigned) {
+  APSIntPtr getIntValue(uint64_t X, bool isUnsigned) {
     QualType T = isUnsigned ? Ctx.UnsignedIntTy : Ctx.IntTy;
     return getValue(X, T);
   }
 
-  const llvm::APSInt &getMaxValue(const llvm::APSInt &v) {
+  APSIntPtr getMaxValue(const llvm::APSInt &v) {
     return getValue(APSIntType(v).getMaxValue());
   }
 
-  const llvm::APSInt &getMinValue(const llvm::APSInt &v) {
+  APSIntPtr getMinValue(const llvm::APSInt &v) {
     return getValue(APSIntType(v).getMinValue());
   }
 
-  const llvm::APSInt &getMaxValue(QualType T) {
-    return getMaxValue(getAPSIntType(T));
-  }
+  APSIntPtr getMaxValue(QualType T) { return getMaxValue(getAPSIntType(T)); }
 
-  const llvm::APSInt &getMinValue(QualType T) {
-    return getMinValue(getAPSIntType(T));
-  }
+  APSIntPtr getMinValue(QualType T) { return getMinValue(getAPSIntType(T)); }
 
-  const llvm::APSInt &getMaxValue(APSIntType T) {
-    return getValue(T.getMaxValue());
-  }
+  APSIntPtr getMaxValue(APSIntType T) { return getValue(T.getMaxValue()); }
 
-  const llvm::APSInt &getMinValue(APSIntType T) {
-    return getValue(T.getMinValue());
-  }
+  APSIntPtr getMinValue(APSIntType T) { return getValue(T.getMinValue()); }
 
-  const llvm::APSInt &Add1(const llvm::APSInt &V) {
+  APSIntPtr Add1(const llvm::APSInt &V) {
     llvm::APSInt X = V;
     ++X;
     return getValue(X);
   }
 
-  const llvm::APSInt &Sub1(const llvm::APSInt &V) {
+  APSIntPtr Sub1(const llvm::APSInt &V) {
     llvm::APSInt X = V;
     --X;
     return getValue(X);
   }
 
-  const llvm::APSInt &getZeroWithTypeSize(QualType T) {
+  APSIntPtr getZeroWithTypeSize(QualType T) {
     assert(T->isScalarType());
     return getValue(0, Ctx.getTypeSize(T), true);
   }
 
-  const llvm::APSInt &getTruthValue(bool b, QualType T) {
+  APSIntPtr getTruthValue(bool b, QualType T) {
     return getValue(b ? 1 : 0, Ctx.getIntWidth(T),
                     T->isUnsignedIntegerOrEnumerationType());
   }
 
-  const llvm::APSInt &getTruthValue(bool b) {
+  APSIntPtr getTruthValue(bool b) {
     return getTruthValue(b, Ctx.getLogicalOperationType());
   }
 
@@ -273,9 +265,9 @@ class BasicValueFactory {
   accumCXXBase(llvm::iterator_range<CastExpr::path_const_iterator> PathRange,
                const nonloc::PointerToMember &PTM, const clang::CastKind &kind);
 
-  const llvm::APSInt* evalAPSInt(BinaryOperator::Opcode Op,
-                                     const llvm::APSInt& V1,
-                                     const llvm::APSInt& V2);
+  std::optional<APSIntPtr> evalAPSInt(BinaryOperator::Opcode Op,
+                                      const llvm::APSInt &V1,
+                                      const llvm::APSInt &V2);
 
   const std::pair<SVal, uintptr_t>&
   getPersistentSValWithData(const SVal& V, uintptr_t Data);
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h
@@ -70,7 +70,6 @@ template <typename T> struct ProgramStateTrait {
 ///  values will never change.
 class ProgramState : public llvm::FoldingSetNode {
 public:
-  typedef llvm::ImmutableSet<llvm::APSInt*>                IntSetTy;
   typedef llvm::ImmutableMap<void*, void*>                 GenericDataMap;
 
 private:
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConstraintManager.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConstraintManager.h
@@ -16,6 +16,7 @@
 
 #include "clang/Basic/JsonSupport.h"
 #include "clang/Basic/TargetInfo.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/RangedConstraintManager.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/SMTConv.h"
 #include <optional>
@@ -154,7 +155,7 @@ class SMTConstraintManager : public clang::ento::SimpleConstraintManager {
         return nullptr;
 
       // This is the only solution, store it
-      return &BVF.getValue(Value);
+      return BVF.getValue(Value).get();
     }
 
     if (const SymbolCast *SC = dyn_cast<SymbolCast>(Sym)) {
@@ -167,7 +168,7 @@ class SMTConstraintManager : public clang::ento::SimpleConstraintManager {
       const llvm::APSInt *Value;
       if (!(Value = getSymVal(State, CastSym)))
         return nullptr;
-      return &BVF.Convert(SC->getType(), *Value);
+      return BVF.Convert(SC->getType(), *Value).get();
     }
 
     if (const BinarySymExpr *BSE = dyn_cast<BinarySymExpr>(Sym)) {
@@ -195,7 +196,9 @@ class SMTConstraintManager : public clang::ento::SimpleConstraintManager {
       std::tie(ConvertedRHS, RTy) = SMTConv::fixAPSInt(Ctx, *RHS);
       SMTConv::doIntTypeConversion<llvm::APSInt, &SMTConv::castAPSInt>(
           Solver, Ctx, ConvertedLHS, LTy, ConvertedRHS, RTy);
-      return BVF.evalAPSInt(BSE->getOpcode(), ConvertedLHS, ConvertedRHS);
+      std::optional<APSIntPtr> Res =
+          BVF.evalAPSInt(BSE->getOpcode(), ConvertedLHS, ConvertedRHS);
+      return Res ? Res.value().get() : nullptr;
     }
 
     llvm_unreachable("Unsupported expression to get symbol value!");
diff --git a/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
@@ -1025,8 +1025,8 @@ SVal CStringChecker::getCStringLengthForRegion(CheckerContext &C,
       BasicValueFactory &BVF = svalBuilder.getBasicValueFactory();
       const llvm::APSInt &maxValInt = BVF.getMaxValue(sizeTy);
       llvm::APSInt fourInt = APSIntType(maxValInt).getValue(4);
-      const llvm::APSInt *maxLengthInt = BVF.evalAPSInt(BO_Div, maxValInt,
-                                                        fourInt);
+      std::optional<APSIntPtr> maxLengthInt =
+          BVF.evalAPSInt(BO_Div, maxValInt, fourInt);
       NonLoc maxLength = svalBuilder.makeIntVal(*maxLengthInt);
       SVal evalLength = svalBuilder.evalBinOpNN(state, BO_LE, *strLn, maxLength,
                                                 svalBuilder.getConditionType());
diff --git a/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
@@ -1643,7 +1643,7 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
   public:
     GetMaxValue(BasicValueFactory &BVF) : BVF(BVF) {}
     std::optional<RangeInt> operator()(QualType Ty) {
-      return BVF.getMaxValue(Ty).getLimitedValue();
+      return BVF.getMaxValue(Ty)->getLimitedValue();
     }
     std::optional<RangeInt> operator()(std::optional<QualType> Ty) {
       if (Ty) {
@@ -1687,11 +1687,11 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
   const QualType SizePtrTy = getPointerTy(SizeTy);
   const QualType SizePtrRestrictTy = getRestrictTy(SizePtrTy);
 
-  const RangeInt IntMax = BVF.getMaxValue(IntTy).getLimitedValue();
+  const RangeInt IntMax = BVF.getMaxValue(IntTy)->getLimitedValue();
   const RangeInt UnsignedIntMax =
-      BVF.getMaxValue(UnsignedIntTy).getLimitedValue();
-  const RangeInt LongMax = BVF.getMaxValue(LongTy).getLimitedValue();
-  const RangeInt SizeMax = BVF.getMaxValue(SizeTy).getLimitedValue();
+      BVF.getMaxValue(UnsignedIntTy)->getLimitedValue();
+  const RangeInt LongMax = BVF.getMaxValue(LongTy)->getLimitedValue();
+  const RangeInt SizeMax = BVF.getMaxValue(SizeTy)->getLimitedValue();
 
   // Set UCharRangeMax to min of int or uchar maximum value.
   // The C standard states that the arguments of functions like isalpha must
@@ -1700,7 +1700,7 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
   // to be true for commonly used and well tested instruction set
   // architectures, but not for others.
   const RangeInt UCharRangeMax =
-      std::min(BVF.getMaxValue(ACtx.UnsignedCharTy).getLimitedValue(), IntMax);
+      std::min(BVF.getMaxValue(ACtx.UnsignedCharTy)->getLimitedValue(), IntMax);
 
   // Get platform dependent values of some macros.
   // Try our best to parse this from the Preprocessor, otherwise fallback to a
@@ -3704,7 +3704,7 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
 
   // Functions for testing.
   if (AddTestFunctions) {
-    const RangeInt IntMin = BVF.getMinValue(IntTy).getLimitedValue();
+    const RangeInt IntMin = BVF.getMinValue(IntTy)->getLimitedValue();
 
     addToFunctionSummaryMap(
         "__not_null", Signature(ArgTypes{IntPtrTy}, RetType{IntTy}),
diff --git a/clang/lib/StaticAnalyzer/Checkers/VLASizeChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/VLASizeChecker.cpp
@@ -96,7 +96,7 @@ ProgramStateRef VLASizeChecker::checkVLA(CheckerContext &C,
   SValBuilder &SVB = C.getSValBuilder();
   CanQualType SizeTy = Ctx.getSizeType();
   uint64_t SizeMax =
-      SVB.getBasicValueFactory().getMaxValue(SizeTy).getZExtValue();
+      SVB.getBasicValueFactory().getMaxValue(SizeTy)->getZExtValue();
 
   // Get the element size.
   CharUnits EleSize = Ctx.getTypeSizeInChars(VLALast->getElementType());
diff --git a/clang/lib/StaticAnalyzer/Core/BasicValueFactory.cpp b/clang/lib/StaticAnalyzer/Core/BasicValueFactory.cpp
diff --git a/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp b/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
