[clang][dataflow] Enable use of synthetic properties on all Value instances.

[wyt]

Summary

This patch moves the implementation of synthetic properties from the StructValue class into the Value base class so that it can be used across all Value instances.

[ymandel]

Thanks!

[sgatev]

clang/include/clang/Analysis/FlowSensitive/Value.h

29

I'm not sure I understand what is meant by "separately allocated" and "stored by pointer". Could you please clarify?

[gribozavr2]

clang/include/clang/Analysis/FlowSensitive/Value.h

29–30

[wyt]

Remove cast to StructValues since get/setProperty can be used directly on Values now

[wyt]

clang/include/clang/Analysis/FlowSensitive/Value.h

29

(See suggested fix by Dmitri)
When we create a new Value instance, we let DataflowAnalysisCtx take ownership of the value and refer to it by pointer.

[gribozavr2]

clang/include/clang/Analysis/FlowSensitive/Value.h

28–30

Please add a blank line between the short description and the rest.

clang/include/clang/Analysis/FlowSensitive/Value.h

 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
 #include <cassert>
 #include <utility>
 
 namespace clang {
 namespace dataflow {
 
 /// Base class for all values computed by abstract interpretation.
+/// All Value instances should be separately allocated and stored by pointer
+/// for pointer stability.
 class Value {
 public:
   enum class Kind {
     Integer,
     Reference,
     Pointer,
     Struct,
 
     // Synthetic boolean values are either atomic values or composites that
     // represent conjunctions, disjunctions, and negations.
     AtomicBool,
     Conjunction,
     Disjunction,
     Negation
   };
 
   explicit Value(Kind ValKind) : ValKind(ValKind) {}
 
   virtual ~Value() = default;
 
   Kind getKind() const { return ValKind; }
 
+  /// Returns the value of the synthetic property with the given `Name` or null
+  /// if the property isn't assigned a value.
+  Value *getProperty(llvm::StringRef Name) const {
+    auto It = Properties.find(Name);
+    return It == Properties.end() ? nullptr : It->second;
+  }
+
+  /// Assigns `Val` as the value of the synthetic property with the given
+  /// `Name`.
+  void setProperty(llvm::StringRef Name, Value &Val) {
+    Properties.insert_or_assign(Name, &Val);
+  }
+
 private:
   Kind ValKind;
+  llvm::StringMap<Value *> Properties;
 };
 
 /// Models a boolean.
 class BoolValue : public Value {
 public:
   explicit BoolValue(Kind ValueKind) : Value(ValueKind) {}
 
   static bool classof(const Value *Val) {
Value *getChild(const ValueDecl &D) const {
     if (It == Children.end())
       return nullptr;
     return It->second;
   }
 
   /// Assigns `Val` as the child value for `D`.
   void setChild(const ValueDecl &D, Value &Val) { Children[&D] = &Val; }
 
-  /// Returns the value of the synthetic property with the given `Name` or null
-  /// if the property isn't assigned a value.
-  Value *getProperty(llvm::StringRef Name) const {
-    auto It = Properties.find(Name);
-    return It == Properties.end() ? nullptr : It->second;
-  }
-
-  /// Assigns `Val` as the value of the synthetic property with the given
-  /// `Name`.
-  void setProperty(llvm::StringRef Name, Value &Val) {
-    Properties.insert_or_assign(Name, &Val);
-  }
-
 private:
   llvm::DenseMap<const ValueDecl *, Value *> Children;
-  llvm::StringMap<Value *> Properties;
 };
 
 } // namespace dataflow
 } // namespace clang
 
 #endif // LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_VALUE_H