Revert "[Clang] Make the SizeType, SignedSizeType and PtrdiffType be named sugar types instead of built-in types (llvm#143653)"

This reverts commit c27e283.

A builbot failure has been reported:
https://lab.llvm.org/buildbot/#/builders/186/builds/10819/steps/10/logs/stdio

I'm also getting a large number of warnings related to %zu and %zx.

Author: kazutakahirata

clang-tools-extra/clangd/unittests/FindTargetTests.cpp

@@ -838,7 +838,7 @@ TEST_F(TargetDeclTest, OverloadExpr) {
   )cpp";
   // Sized deallocation is enabled by default in C++14 onwards.
   EXPECT_DECLS("CXXDeleteExpr",
-               "void operator delete(void *, __size_t) noexcept");
+               "void operator delete(void *, unsigned long) noexcept");
 }
 
 TEST_F(TargetDeclTest, DependentExprs) {

clang-tools-extra/clangd/unittests/HoverTests.cpp

@@ -2794,7 +2794,7 @@ TEST(Hover, All) {
           })cpp",
           [](HoverInfo &HI) {
             HI.Name = "expression";
-            HI.Type = {"__size_t", "unsigned long"};
+            HI.Type = "unsigned long";
             HI.Value = "1";
           }},
       {
@@ -2804,7 +2804,7 @@ TEST(Hover, All) {
           })cpp",
           [](HoverInfo &HI) {
             HI.Name = "expression";
-            HI.Type = {"__size_t", "unsigned long"};
+            HI.Type = "unsigned long";
             HI.Value = "1";
           }},
       {

clang/docs/ReleaseNotes.rst

@@ -46,7 +46,6 @@ Potentially Breaking Changes
   ``endbr64`` instruction at the labels named as possible branch
   destinations, so it is not safe to use a register-controlled branch
   instruction to branch to one. (In line with gcc.)
-- Added a sugar type `PredefinedSugarType` to improve diagnostic messages. (#GH143653)
 
 C/C++ Language Potentially Breaking Changes
 -------------------------------------------

clang/include/clang/AST/ASTContext.h

@@ -277,11 +277,6 @@ class ASTContext : public RefCountedBase<ASTContext> {
   mutable llvm::ContextualFoldingSet<ArrayParameterType, ASTContext &>
       ArrayParameterTypes;
 
-  /// Store the unique Type corresponding to each Kind.
-  mutable std::array<Type *,
-                     llvm::to_underlying(PredefinedSugarType::Kind::Last) + 1>
-      PredefinedSugarTypes{};
-
   /// The set of nested name specifiers.
   ///
   /// This set is managed by the NestedNameSpecifier class.
@@ -1572,8 +1567,6 @@ class ASTContext : public RefCountedBase<ASTContext> {
   /// and bit count.
   QualType getDependentBitIntType(bool Unsigned, Expr *BitsExpr) const;
 
-  QualType getPredefinedSugarType(PredefinedSugarType::Kind KD) const;
-
   /// Gets the struct used to keep track of the extended descriptor for
   /// pointer to blocks.
   QualType getBlockDescriptorExtendedType() const;
@@ -2006,13 +1999,11 @@ class ASTContext : public RefCountedBase<ASTContext> {
   /// <stddef.h>.
   ///
   /// The sizeof operator requires this (C99 6.5.3.4p4).
-  QualType getSizeType() const;
-
-  CanQualType getCanonicalSizeType() const;
+  CanQualType getSizeType() const;
 
   /// Return the unique signed counterpart of
   /// the integer type corresponding to size_t.
-  QualType getSignedSizeType() const;
+  CanQualType getSignedSizeType() const;
 
   /// Return the unique type for "intmax_t" (C99 7.18.1.5), defined in
   /// <stdint.h>.

clang/include/clang/AST/FormatString.h

@@ -489,8 +489,7 @@ class FormatSpecifier {
 
   /// For a TypedefType QT, if it is a named integer type such as size_t,
   /// assign the appropriate value to LM and return true.
-  static bool namedTypeToLengthModifier(ASTContext &Ctx, QualType QT,
-                                        LengthModifier &LM);
+  static bool namedTypeToLengthModifier(QualType QT, LengthModifier &LM);
 };
 
 } // end analyze_format_string namespace

clang/include/clang/AST/RecursiveASTVisitor.h

@@ -1208,8 +1208,6 @@ DEF_TRAVERSE_TYPE(BitIntType, {})
 DEF_TRAVERSE_TYPE(DependentBitIntType,
                   { TRY_TO(TraverseStmt(T->getNumBitsExpr())); })
 
-DEF_TRAVERSE_TYPE(PredefinedSugarType, {})
-
 #undef DEF_TRAVERSE_TYPE
 
 // ----------------- TypeLoc traversal -----------------
@@ -1526,8 +1524,6 @@ DEF_TRAVERSE_TYPELOC(DependentBitIntType, {
   TRY_TO(TraverseStmt(TL.getTypePtr()->getNumBitsExpr()));
 })
 
-DEF_TRAVERSE_TYPELOC(PredefinedSugarType, {})
-
 #undef DEF_TRAVERSE_TYPELOC
 
 // ----------------- Decl traversal -----------------

clang/include/clang/AST/Type.h

@@ -2258,30 +2258,6 @@ class alignas(TypeAlignment) Type : public ExtQualsTypeCommonBase {
     unsigned NumExpansions;
   };
 
-  enum class PredefinedSugarKind {
-    /// The "size_t" type.
-    SizeT,
-
-    /// The signed integer type corresponding to "size_t".
-    SignedSizeT,
-
-    /// The "ptrdiff_t" type.
-    PtrdiffT,
-
-    // Indicates how many items the enum has.
-    Last = PtrdiffT
-  };
-
-  class PresefinedSugarTypeBitfields {
-    friend class PredefinedSugarType;
-
-    LLVM_PREFERRED_TYPE(TypeBitfields)
-    unsigned : NumTypeBits;
-
-    LLVM_PREFERRED_TYPE(PredefinedSugarKind)
-    unsigned Kind : 8;
-  };
-
   class CountAttributedTypeBitfields {
     friend class CountAttributedType;
 
@@ -2321,7 +2297,6 @@ class alignas(TypeAlignment) Type : public ExtQualsTypeCommonBase {
       DependentTemplateSpecializationTypeBits;
     PackExpansionTypeBitfields PackExpansionTypeBits;
     CountAttributedTypeBitfields CountAttributedTypeBits;
-    PresefinedSugarTypeBitfields PredefinedSugarTypeBits;
   };
 
 private:
@@ -8063,37 +8038,6 @@ class DependentBitIntType final : public Type, public llvm::FoldingSetNode {
   }
 };
 
-class PredefinedSugarType final : public Type {
-public:
-  friend class ASTContext;
-  using Kind = PredefinedSugarKind;
-
-private:
-  PredefinedSugarType(Kind KD, const IdentifierInfo *IdentName,
-                      QualType CanonicalType)
-      : Type(PredefinedSugar, CanonicalType, TypeDependence::None),
-        Name(IdentName) {
-    PredefinedSugarTypeBits.Kind = llvm::to_underlying(KD);
-  }
-
-  static StringRef getName(Kind KD);
-
-  const IdentifierInfo *Name;
-
-public:
-  bool isSugared() const { return true; }
-
-  QualType desugar() const { return getCanonicalTypeInternal(); }
-
-  Kind getKind() const { return Kind(PredefinedSugarTypeBits.Kind); }
-
-  const IdentifierInfo *getIdentifier() const { return Name; }
-
-  static bool classof(const Type *T) {
-    return T->getTypeClass() == PredefinedSugar;
-  }
-};
-
 /// A qualifier set is used to build a set of qualifiers.
 class QualifierCollector : public Qualifiers {
 public:

clang/include/clang/AST/TypeLoc.h

@@ -2783,16 +2783,6 @@ class ObjCProtocolLoc {
   }
 };
 
-struct PredefinedSugarTypeLocInfo {}; // Nothing.
-
-class PredefinedSugarTypeLoc final
-    : public ConcreteTypeLoc<UnqualTypeLoc, PredefinedSugarTypeLoc,
-                             PredefinedSugarType, PredefinedSugarTypeLocInfo> {
-public:
-  void initializeLocal(ASTContext &Context, SourceLocation loc) {}
-  SourceRange getLocalSourceRange() const { return {}; }
-};
-
 } // namespace clang
 
 #endif // LLVM_CLANG_AST_TYPELOC_H

clang/include/clang/AST/TypeProperties.td

@@ -1028,12 +1028,3 @@ let Class = DependentBitIntType in {
     return ctx.getDependentBitIntType(isUnsigned, numBitsExpr);
   }]>;
 }
-
-let Class = PredefinedSugarType in {
-  def : Property<"kind", UInt32> {
-    let Read = [{ static_cast<uint32_t>(node->getKind()) }];
-  }
-  def : Creator<[{
-    return ctx.getPredefinedSugarType(static_cast<PredefinedSugarType::Kind>(kind));
-  }]>;
-}

clang/include/clang/Basic/TypeNodes.td

@@ -117,4 +117,3 @@ def PipeType : TypeNode<Type>;
 def AtomicType : TypeNode<Type>;
 def BitIntType : TypeNode<Type>;
 def DependentBitIntType : TypeNode<Type>, AlwaysDependent;
-def PredefinedSugarType : TypeNode<Type>, NeverCanonical;