EIC code displayed by LXR master/​include/​clang/​Analysis/​FlowSensitive/​Arena.h	Source navigation Diff markup Identifier search General search
	Version: master test Revert   Change

File indexing completed on 2026-05-10 08:36:24

 //===-- Arena.h -------------------------------*- 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_ANALYSIS_FLOWSENSITIVE__ARENA_H
 #define LLVM_CLANG_ANALYSIS_FLOWSENSITIVE__ARENA_H
 
 #include "clang/Analysis/FlowSensitive/Formula.h"
 #include "clang/Analysis/FlowSensitive/StorageLocation.h"
 #include "clang/Analysis/FlowSensitive/Value.h"
 #include "llvm/ADT/StringRef.h"
 #include <vector>
 
 namespace clang::dataflow {
 
 /// The Arena owns the objects that model data within an analysis.
 /// For example, `Value`, `StorageLocation`, `Atom`, and `Formula`.
 class Arena {
 public:
   Arena()
       : True(Formula::create(Alloc, Formula::Literal, {}, 1)),
         False(Formula::create(Alloc, Formula::Literal, {}, 0)) {}
   Arena(const Arena &) = delete;
   Arena &operator=(const Arena &) = delete;
 
   /// Creates a `T` (some subclass of `StorageLocation`), forwarding `args` to
   /// the constructor, and returns a reference to it.
   ///
   /// The `Arena` takes ownership of the created object. The object will be
   /// destroyed when the `Arena` is destroyed.
   template <typename T, typename... Args>
   std::enable_if_t<std::is_base_of<StorageLocation, T>::value, T &>
   create(Args &&...args) {
     // Note: If allocation of individual `StorageLocation`s turns out to be
     // costly, consider creating specializations of `create<T>` for commonly
     // used `StorageLocation` subclasses and make them use a `BumpPtrAllocator`.
     return *cast<T>(
         Locs.emplace_back(std::make_unique<T>(std::forward<Args>(args)...))
             .get());
   }
 
   /// Creates a `T` (some subclass of `Value`), forwarding `args` to the
   /// constructor, and returns a reference to it.
   ///
   /// The `Arena` takes ownership of the created object. The object will be
   /// destroyed when the `Arena` is destroyed.
   template <typename T, typename... Args>
   std::enable_if_t<std::is_base_of<Value, T>::value, T &>
   create(Args &&...args) {
     // Note: If allocation of individual `Value`s turns out to be costly,
     // consider creating specializations of `create<T>` for commonly used
     // `Value` subclasses and make them use a `BumpPtrAllocator`.
     return *cast<T>(
         Vals.emplace_back(std::make_unique<T>(std::forward<Args>(args)...))
             .get());
   }
 
   /// Creates a BoolValue wrapping a particular formula.
   ///
   /// Passing in the same formula will result in the same BoolValue.
   /// FIXME: Interning BoolValues but not other Values is inconsistent.
   ///        Decide whether we want Value interning or not.
   BoolValue &makeBoolValue(const Formula &);
 
   /// Creates a fresh atom and wraps in in an AtomicBoolValue.
   /// FIXME: For now, identical-address AtomicBoolValue <=> identical atom.
   ///        Stop relying on pointer identity and remove this guarantee.
   AtomicBoolValue &makeAtomValue() {
     return cast<AtomicBoolValue>(makeBoolValue(makeAtomRef(makeAtom())));
   }
 
   /// Creates a fresh Top boolean value.
   TopBoolValue &makeTopValue() {
     // No need for deduplicating: there's no way to create aliasing Tops.
     return create<TopBoolValue>(makeAtomRef(makeAtom()));
   }
 
   /// Returns a symbolic integer value that models an integer literal equal to
   /// `Value`. These literals are the same every time.
   /// Integer literals are not typed; the type is determined by the `Expr` that
   /// an integer literal is associated with.
   IntegerValue &makeIntLiteral(llvm::APInt Value);
 
   // Factories for boolean formulas.
   // Formulas are interned: passing the same arguments return the same result.
   // For commutative operations like And/Or, interning ignores order.
   // Simplifications are applied: makeOr(X, X) => X, etc.
 
   /// Returns a formula for the conjunction of `LHS` and `RHS`.
   const Formula &makeAnd(const Formula &LHS, const Formula &RHS);
 
   /// Returns a formula for the disjunction of `LHS` and `RHS`.
   const Formula &makeOr(const Formula &LHS, const Formula &RHS);
 
   /// Returns a formula for the negation of `Val`.
   const Formula &makeNot(const Formula &Val);
 
   /// Returns a formula for `LHS => RHS`.
   const Formula &makeImplies(const Formula &LHS, const Formula &RHS);
 
   /// Returns a formula for `LHS <=> RHS`.
   const Formula &makeEquals(const Formula &LHS, const Formula &RHS);
 
   /// Returns a formula for the variable A.
   const Formula &makeAtomRef(Atom A);
 
   /// Returns a formula for a literal true/false.
   const Formula &makeLiteral(bool Value) { return Value ? True : False; }
 
   // Parses a formula from its textual representation.
   // This may refer to atoms that were not produced by makeAtom() yet!
   llvm::Expected<const Formula &> parseFormula(llvm::StringRef);
 
   /// Returns a new atomic boolean variable, distinct from any other.
   Atom makeAtom() { return static_cast<Atom>(NextAtom++); };
 
   /// Creates a fresh flow condition and returns a token that identifies it. The
   /// token can be used to perform various operations on the flow condition such
   /// as adding constraints to it, forking it, joining it with another flow
   /// condition, or checking implications.
   Atom makeFlowConditionToken() { return makeAtom(); }
 
 private:
   llvm::BumpPtrAllocator Alloc;
 
   // Storage for the state of a program.
   std::vector<std::unique_ptr<StorageLocation>> Locs;
   std::vector<std::unique_ptr<Value>> Vals;
 
   // Indices that are used to avoid recreating the same integer literals and
   // composite boolean values.
   llvm::DenseMap<llvm::APInt, IntegerValue *> IntegerLiterals;
   using FormulaPair = std::pair<const Formula *, const Formula *>;
   llvm::DenseMap<FormulaPair, const Formula *> Ands;
   llvm::DenseMap<FormulaPair, const Formula *> Ors;
   llvm::DenseMap<const Formula *, const Formula *> Nots;
   llvm::DenseMap<FormulaPair, const Formula *> Implies;
   llvm::DenseMap<FormulaPair, const Formula *> Equals;
   llvm::DenseMap<Atom, const Formula *> AtomRefs;
 
   llvm::DenseMap<const Formula *, BoolValue *> FormulaValues;
   unsigned NextAtom = 0;
 
   const Formula &True, &False;
 };
 
 } // namespace clang::dataflow
 
 #endif // LLVM_CLANG_ANALYSIS_FLOWSENSITIVE__ARENA_H

This page was automatically generated by the 2.3.7 LXR engine. The LXR team