[PATCH] D50713: [AST] Pack the unsigned of SubstTemplateTypeParmPackType into Type

[Bruno Ricci via Phabricator via cfe-commits]

riccibruno created this revision.
riccibruno added reviewers: rsmith, rjmccall, erichkeane.
riccibruno added a project: clang.
Herald added a reviewer: javed.absar.
Herald added subscribers: cfe-commits, chrib, kristof.beyls.

The bit-fields of `Type` have enough space for the member
`unsigned NumArgs` of SubstTemplateTypeParmPackType.


Repository:
  rC Clang

https://reviews.llvm.org/D50713

Files:
  include/clang/AST/Type.h
  lib/AST/Type.cpp


Index: lib/AST/Type.cpp
===================================================================
--- lib/AST/Type.cpp
+++ lib/AST/Type.cpp
@@ -3285,11 +3285,12 @@
                               QualType Canon,
                               const TemplateArgument &ArgPack)
     : Type(SubstTemplateTypeParmPack, Canon, true, true, false, true),
-      Replaced(Param),
-      Arguments(ArgPack.pack_begin()), NumArguments(ArgPack.pack_size()) {}
+      Replaced(Param), Arguments(ArgPack.pack_begin()) {
+  SubstTemplateTypeParmPackTypeBits.NumArgs = ArgPack.pack_size();
+}
 
 TemplateArgument SubstTemplateTypeParmPackType::getArgumentPack() const {
-  return TemplateArgument(llvm::makeArrayRef(Arguments, NumArguments));
+  return TemplateArgument(llvm::makeArrayRef(Arguments, getNumArgs()));
 }
 
 void SubstTemplateTypeParmPackType::Profile(llvm::FoldingSetNodeID &ID) {
Index: include/clang/AST/Type.h
===================================================================
--- include/clang/AST/Type.h
+++ include/clang/AST/Type.h
@@ -1626,6 +1626,16 @@
     unsigned Keyword : 2;
   };
 
+  class SubstTemplateTypeParmPackTypeBitfields {
+    friend class SubstTemplateTypeParmPackType;
+
+    unsigned : NumTypeBits;
+
+    /// The number of template arguments in \c Arguments.
+    /// Intentionally not a bitfield since we have plenty of space left.
+    unsigned NumArgs;
+  };
+
   class TemplateSpecializationTypeBitfields {
     friend class TemplateSpecializationType;
 
@@ -1678,6 +1688,7 @@
     ReferenceTypeBitfields ReferenceTypeBits;
     TypeWithKeywordBitfields TypeWithKeywordBits;
     VectorTypeBitfields VectorTypeBits;
+    SubstTemplateTypeParmPackTypeBitfields SubstTemplateTypeParmPackTypeBits;
     TemplateSpecializationTypeBitfields TemplateSpecializationTypeBits;
     DependentTemplateSpecializationTypeBitfields
       DependentTemplateSpecializationTypeBits;
@@ -1703,6 +1714,9 @@
                   "TypeWithKeywordBitfields is larger than 8 bytes!");
     static_assert(sizeof(VectorTypeBitfields) <= 8,
                   "VectorTypeBitfields is larger than 8 bytes!");
+    static_assert(sizeof(SubstTemplateTypeParmPackTypeBitfields) <= 8,
+                  "SubstTemplateTypeParmPackTypeBitfields is larger"
+                  " than 8 bytes!");
     static_assert(sizeof(TemplateSpecializationTypeBitfields) <= 8,
                   "TemplateSpecializationTypeBitfields is larger"
                   " than 8 bytes!");
@@ -4543,9 +4557,6 @@
   /// parameter pack is instantiated with.
   const TemplateArgument *Arguments;
 
-  /// The number of template arguments in \c Arguments.
-  unsigned NumArguments;
-
   SubstTemplateTypeParmPackType(const TemplateTypeParmType *Param,
                                 QualType Canon,
                                 const TemplateArgument &ArgPack);
@@ -4558,6 +4569,10 @@
     return Replaced;
   }
 
+  unsigned getNumArgs() const {
+    return SubstTemplateTypeParmPackTypeBits.NumArgs;
+  }
+
   bool isSugared() const { return false; }
   QualType desugar() const { return QualType(this, 0); }
 


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