1 files changed, 28 insertions, 73 deletions

diff --git a/include/clang/AST/TemplateBase.h b/include/clang/AST/TemplateBase.h
index 65f5460..54c9f2c 100644
--- a/include/clang/AST/TemplateBase.h
+++ b/include/clang/AST/TemplateBase.h
@@ -73,7 +73,15 @@ private:
   union {
     uintptr_t TypeOrValue;
     struct {
-      char Value[sizeof(llvm::APSInt)];
+      // We store a decomposed APSInt with the data allocated by ASTContext if
+      // BitWidth > 64. The memory may be shared between multiple
+      // TemplateArgument instances.
+      union {
+        uint64_t VAL;          ///< Used to store the <= 64 bits integer value.
+        const uint64_t *pVal;  ///< Used to store the >64 bits integer value.
+      };
+      unsigned BitWidth : 31;
+      unsigned IsUnsigned : 1;
       void *Type;
     } Integer;
     struct {
@@ -104,11 +112,15 @@ public:
     TypeOrValue = reinterpret_cast<uintptr_t>(D);
   }
 
-  /// \brief Construct an integral constant template argument.
-  TemplateArgument(const llvm::APSInt &Value, QualType Type) : Kind(Integral) {
-    // FIXME: Large integral values will get leaked. Do something
-    // similar to what we did with IntegerLiteral.
-    new (Integer.Value) llvm::APSInt(Value);
+  /// \brief Construct an integral constant template argument. The memory to
+  /// store the value is allocated with Ctx.
+  TemplateArgument(ASTContext &Ctx, const llvm::APSInt &Value, QualType Type);
+
+  /// \brief Construct an integral constant template argument with the same
+  /// value as Other but a different type.
+  TemplateArgument(const TemplateArgument &Other, QualType Type)
+    : Kind(Integral) {
+    Integer = Other.Integer;
     Integer.Type = Type.getAsOpaquePtr();
   }
 
@@ -165,62 +177,6 @@ public:
     this->Args.NumArgs = NumArgs;
   }
 
-  /// \brief Copy constructor for a template argument.
-  TemplateArgument(const TemplateArgument &Other) : Kind(Other.Kind) {
-    // FIXME: Large integral values will get leaked. Do something
-    // similar to what we did with IntegerLiteral.
-    if (Kind == Integral) {
-      new (Integer.Value) llvm::APSInt(*Other.getAsIntegral());
-      Integer.Type = Other.Integer.Type;
-    } else if (Kind == Pack) {
-      Args.NumArgs = Other.Args.NumArgs;
-      Args.Args = Other.Args.Args;
-    } else if (Kind == Template || Kind == TemplateExpansion) {
-      TemplateArg.Name = Other.TemplateArg.Name;
-      TemplateArg.NumExpansions = Other.TemplateArg.NumExpansions;
-    } else
-      TypeOrValue = Other.TypeOrValue;
-  }
-
-  TemplateArgument& operator=(const TemplateArgument& Other) {
-    using llvm::APSInt;
-
-    if (Kind == Other.Kind && Kind == Integral) {
-      // Copy integral values.
-      *this->getAsIntegral() = *Other.getAsIntegral();
-      Integer.Type = Other.Integer.Type;
-      return *this;
-    } 
-
-    // Destroy the current integral value, if that's what we're holding.
-    if (Kind == Integral)
-      getAsIntegral()->~APSInt();
-
-    Kind = Other.Kind;
-
-    if (Other.Kind == Integral) {
-      new (Integer.Value) llvm::APSInt(*Other.getAsIntegral());
-      Integer.Type = Other.Integer.Type;
-    } else if (Other.Kind == Pack) {
-      Args.NumArgs = Other.Args.NumArgs;
-      Args.Args = Other.Args.Args;
-    } else if (Kind == Template || Kind == TemplateExpansion) {
-      TemplateArg.Name = Other.TemplateArg.Name;
-      TemplateArg.NumExpansions = Other.TemplateArg.NumExpansions;
-    } else {
-      TypeOrValue = Other.TypeOrValue;
-    }
-
-    return *this;
-  }
-
-  ~TemplateArgument() {
-    using llvm::APSInt;
-
-    if (Kind == Integral)
-      getAsIntegral()->~APSInt();
-  }
-
   /// \brief Create a new template argument pack by copying the given set of
   /// template arguments.
   static TemplateArgument CreatePackCopy(ASTContext &Context,
@@ -286,14 +242,15 @@ public:
   llvm::Optional<unsigned> getNumTemplateExpansions() const;
   
   /// \brief Retrieve the template argument as an integral value.
-  llvm::APSInt *getAsIntegral() {
-    if (Kind != Integral)
-      return 0;
-    return reinterpret_cast<llvm::APSInt*>(&Integer.Value[0]);
-  }
+  // FIXME: Provide a way to read the integral data without copying the value.
+  llvm::APSInt getAsIntegral() const {
+    using namespace llvm;
+    if (Integer.BitWidth <= 64)
+      return APSInt(APInt(Integer.BitWidth, Integer.VAL), Integer.IsUnsigned);
 
-  const llvm::APSInt *getAsIntegral() const {
-    return const_cast<TemplateArgument*>(this)->getAsIntegral();
+    unsigned NumWords = APInt::getNumWords(Integer.BitWidth);
+    return APSInt(APInt(Integer.BitWidth, makeArrayRef(Integer.pVal, NumWords)),
+                  Integer.IsUnsigned);
   }
 
   /// \brief Retrieve the type of the integral value.
@@ -342,14 +299,12 @@ public:
     return Args.NumArgs;
   }
 
-  /// Determines whether two template arguments are superficially the
+  /// \brief Determines whether two template arguments are superficially the
   /// same.
   bool structurallyEquals(const TemplateArgument &Other) const;
 
-  /// \brief When the template argument is a pack expansion, returns 
+  /// \brief When the template argument is a pack expansion, returns
   /// the pattern of the pack expansion.
-  ///
-  /// \param Ellipsis Will be set to the location of the ellipsis.
   TemplateArgument getPackExpansionPattern() const;
 
   /// \brief Print this template argument to the given output stream.