Revert old implementation sans tests

Author: Erich Keane

clang/docs/LanguageExtensions.rst

@@ -1794,7 +1794,7 @@ correctly in any circumstances. It can be used if:
   metaprogramming algorithms to be able to specify/detect types generically.
 
 - the generated kernel binary does not contain indirect calls because they
-  are eliminated using compiler optimizations e.g. devirtualization. 
+  are eliminated using compiler optimizations e.g. devirtualization.
 
 - the selected target supports the function pointer like functionality e.g.
   most CPU targets.
@@ -2404,30 +2404,6 @@ argument.
   int *pb =__builtin_preserve_access_index(&v->c[3].b);
   __builtin_preserve_access_index(v->j);
 
-``__builtin_unique_stable_name``
---------------------------------
-
-``__builtin_unique_stable_name()`` is a builtin that takes a type or expression and
-produces a string literal containing a unique name for the type (or type of the
-expression) that is stable across split compilations.
-
-In cases where the split compilation needs to share a unique token for a type
-across the boundary (such as in an offloading situation), this name can be used
-for lookup purposes.
-
-This builtin is superior to RTTI for this purpose for two reasons.  First, this
-value is computed entirely at compile time, so it can be used in constant
-expressions. Second, this value encodes lambda functions based on line-number
-rather than the order in which it appears in a function. This is valuable
-because it is stable in cases where an unrelated lambda is introduced
-conditionally in the same function.
-
-The current implementation of this builtin uses a slightly modified Itanium
-Mangler to produce the unique name. The lambda ordinal is replaced with one or
-more line/column pairs in the format ``LINE->COL``, separated with a ``~``
-character. Typically, only one pair will be included, however in the case of
-macro expansions the entire macro expansion stack is expressed.
-
 Multiprecision Arithmetic Builtins
 ----------------------------------
 
@@ -2622,7 +2598,7 @@ Guaranteed inlined copy
 ``__builtin_memcpy_inline`` has been designed as a building block for efficient
 ``memcpy`` implementations. It is identical to ``__builtin_memcpy`` but also
 guarantees not to call any external functions. See LLVM IR `llvm.memcpy.inline
-<https://llvm.org/docs/LangRef.html#llvm-memcpy-inline-intrinsic>`_ intrinsic 
+<https://llvm.org/docs/LangRef.html#llvm-memcpy-inline-intrinsic>`_ intrinsic
 for more information.
 
 This is useful to implement a custom version of ``memcpy``, implement a

clang/include/clang/AST/Expr.h

@@ -1948,17 +1948,13 @@ class StringLiteral final
 /// [C99 6.4.2.2] - A predefined identifier such as __func__.
 class PredefinedExpr final
     : public Expr,
-      private llvm::TrailingObjects<PredefinedExpr, Stmt *, Expr *,
-                                    TypeSourceInfo *> {
+      private llvm::TrailingObjects<PredefinedExpr, Stmt *> {
   friend class ASTStmtReader;
   friend TrailingObjects;
 
   // PredefinedExpr is optionally followed by a single trailing
   // "Stmt *" for the predefined identifier. It is present if and only if
   // hasFunctionName() is true and is always a "StringLiteral *".
-  // It can also be followed by a Expr* in the case of a
-  // __builtin_unique_stable_name with an expression, or TypeSourceInfo * if
-  // __builtin_unique_stable_name with a type.
 
 public:
   enum IdentKind {
@@ -1971,18 +1967,12 @@ class PredefinedExpr final
     PrettyFunction,
     /// The same as PrettyFunction, except that the
     /// 'virtual' keyword is omitted for virtual member functions.
-    PrettyFunctionNoVirtual,
-    UniqueStableNameType,
-    UniqueStableNameExpr,
+    PrettyFunctionNoVirtual
   };
 
 private:
   PredefinedExpr(SourceLocation L, QualType FNTy, IdentKind IK,
                  StringLiteral *SL);
-  PredefinedExpr(SourceLocation L, QualType FNTy, IdentKind IK,
-                 TypeSourceInfo *Info);
-  PredefinedExpr(SourceLocation L, QualType FNTy, IdentKind IK,
-                 Expr *E);
 
   explicit PredefinedExpr(EmptyShell Empty, bool HasFunctionName);
 
@@ -1995,39 +1985,10 @@ class PredefinedExpr final
     *getTrailingObjects<Stmt *>() = SL;
   }
 
-  void setTypeSourceInfo(TypeSourceInfo *Info) {
-    assert(!hasFunctionName() && getIdentKind() == UniqueStableNameType &&
-           "TypeSourceInfo only valid for UniqueStableName of a Type");
-    *getTrailingObjects<TypeSourceInfo *>() = Info;
-  }
-
-  void setExpr(Expr *E) {
-    assert(!hasFunctionName() && getIdentKind() == UniqueStableNameExpr &&
-           "TypeSourceInfo only valid for UniqueStableName of n Expression.");
-    *getTrailingObjects<Expr *>() = E;
-  }
-
-  size_t numTrailingObjects(OverloadToken<Stmt *>) const {
-    return hasFunctionName();
-  }
-
-  size_t numTrailingObjects(OverloadToken<TypeSourceInfo *>) const {
-    return getIdentKind() == UniqueStableNameType && !hasFunctionName();
-  }
-  size_t numTrailingObjects(OverloadToken<Expr *>) const {
-    return getIdentKind() == UniqueStableNameExpr && !hasFunctionName();
-  }
-
 public:
   /// Create a PredefinedExpr.
   static PredefinedExpr *Create(const ASTContext &Ctx, SourceLocation L,
                                 QualType FNTy, IdentKind IK, StringLiteral *SL);
-  static PredefinedExpr *Create(const ASTContext &Ctx, SourceLocation L,
-                                QualType FNTy, IdentKind IK, StringLiteral *SL,
-                                TypeSourceInfo *Info);
-  static PredefinedExpr *Create(const ASTContext &Ctx, SourceLocation L,
-                                QualType FNTy, IdentKind IK, StringLiteral *SL,
-                                Expr *E);
 
   /// Create an empty PredefinedExpr.
   static PredefinedExpr *CreateEmpty(const ASTContext &Ctx,
@@ -2052,38 +2013,12 @@ class PredefinedExpr final
                : nullptr;
   }
 
-  TypeSourceInfo *getTypeSourceInfo() {
-    assert(!hasFunctionName() && getIdentKind() == UniqueStableNameType &&
-           "TypeSourceInfo only valid for UniqueStableName of a Type");
-    return *getTrailingObjects<TypeSourceInfo *>();
-  }
-
-  const TypeSourceInfo *getTypeSourceInfo() const {
-    assert(!hasFunctionName() && getIdentKind() == UniqueStableNameType &&
-           "TypeSourceInfo only valid for UniqueStableName of a Type");
-    return *getTrailingObjects<TypeSourceInfo *>();
-  }
-
-  Expr *getExpr() {
-    assert(!hasFunctionName() && getIdentKind() == UniqueStableNameExpr &&
-           "TypeSourceInfo only valid for UniqueStableName of n Expression.");
-    return *getTrailingObjects<Expr *>();
-  }
-
-  const Expr *getExpr() const {
-    assert(!hasFunctionName() && getIdentKind() == UniqueStableNameExpr &&
-           "TypeSourceInfo only valid for UniqueStableName of n Expression.");
-    return *getTrailingObjects<Expr *>();
-  }
-
   static StringRef getIdentKindName(IdentKind IK);
   StringRef getIdentKindName() const {
     return getIdentKindName(getIdentKind());
   }
 
   static std::string ComputeName(IdentKind IK, const Decl *CurrentDecl);
-  static std::string ComputeName(ASTContext &Context, IdentKind IK,
-                                 const QualType Ty);
 
   SourceLocation getBeginLoc() const { return getLocation(); }
   SourceLocation getEndLoc() const { return getLocation(); }

clang/include/clang/AST/Mangle.h

@@ -172,14 +172,9 @@ class MangleContext {
 };
 
 class ItaniumMangleContext : public MangleContext {
-  bool IsUniqueNameMangler = false;
 public:
   explicit ItaniumMangleContext(ASTContext &C, DiagnosticsEngine &D)
       : MangleContext(C, D, MK_Itanium) {}
-  explicit ItaniumMangleContext(ASTContext &C, DiagnosticsEngine &D,
-                                bool IsUniqueNameMangler)
-      : MangleContext(C, D, MK_Itanium),
-        IsUniqueNameMangler(IsUniqueNameMangler) {}
 
   virtual void mangleCXXVTable(const CXXRecordDecl *RD, raw_ostream &) = 0;
   virtual void mangleCXXVTT(const CXXRecordDecl *RD, raw_ostream &) = 0;
@@ -200,15 +195,12 @@ class ItaniumMangleContext : public MangleContext {
 
   virtual void mangleDynamicStermFinalizer(const VarDecl *D, raw_ostream &) = 0;
 
-  bool isUniqueNameMangler() { return IsUniqueNameMangler; }
-
   static bool classof(const MangleContext *C) {
     return C->getKind() == MK_Itanium;
   }
 
   static ItaniumMangleContext *create(ASTContext &Context,
-                                      DiagnosticsEngine &Diags,
-                                      bool IsUniqueNameMangler = false);
+                                      DiagnosticsEngine &Diags);
 };
 
 class MicrosoftMangleContext : public MangleContext {

clang/include/clang/Basic/TokenKinds.def

@@ -695,12 +695,11 @@ ALIAS("_declspec"        , __declspec , KEYMS)
 ALIAS("_pascal"      , __pascal   , KEYBORLAND)
 
 // Clang Extensions.
-KEYWORD(__builtin_convertvector     , KEYALL)
-ALIAS("__char16_t"   , char16_t     , KEYCXX)
-ALIAS("__char32_t"   , char32_t     , KEYCXX)
-KEYWORD(__builtin_bit_cast          , KEYALL)
-KEYWORD(__builtin_available         , KEYALL)
-KEYWORD(__builtin_unique_stable_name, KEYALL)
+KEYWORD(__builtin_convertvector   , KEYALL)
+ALIAS("__char16_t"   , char16_t   , KEYCXX)
+ALIAS("__char32_t"   , char32_t   , KEYCXX)
+KEYWORD(__builtin_bit_cast        , KEYALL)
+KEYWORD(__builtin_available       , KEYALL)
 
 // Clang-specific keywords enabled only in testing.
 TESTING_KEYWORD(__unknown_anytype , KEYALL)

clang/include/clang/Parse/Parser.h

@@ -1800,7 +1800,6 @@ class Parser : public CodeCompletionHandler {
   ExprResult ParsePostfixExpressionSuffix(ExprResult LHS);
   ExprResult ParseUnaryExprOrTypeTraitExpression();
   ExprResult ParseBuiltinPrimaryExpression();
-  ExprResult ParseUniqueStableNameExpression();
 
   ExprResult ParseExprAfterUnaryExprOrTypeTrait(const Token &OpTok,
                                                      bool &isCastExpr,

clang/include/clang/Sema/Sema.h

@@ -5420,15 +5420,6 @@ class Sema final {
   ExprResult ActOnPredefinedExpr(SourceLocation Loc, tok::TokenKind Kind);
   ExprResult ActOnIntegerConstant(SourceLocation Loc, uint64_t Val);
 
-  ExprResult BuildUniqueStableName(SourceLocation Loc, TypeSourceInfo *Operand);
-  ExprResult BuildUniqueStableName(SourceLocation Loc, Expr *E);
-  ExprResult ActOnUniqueStableNameExpr(SourceLocation OpLoc,
-                                       SourceLocation LParen,
-                                       SourceLocation RParen, ParsedType Ty);
-  ExprResult ActOnUniqueStableNameExpr(SourceLocation OpLoc,
-                                       SourceLocation LParen,
-                                       SourceLocation RParen, Expr *E);
-
   bool CheckLoopHintExpr(Expr *E, SourceLocation Loc);
 
   ExprResult ActOnNumericConstant(const Token &Tok, Scope *UDLScope = nullptr);

clang/lib/AST/Expr.cpp

@@ -518,34 +518,6 @@ PredefinedExpr::PredefinedExpr(SourceLocation L, QualType FNTy, IdentKind IK,
   setDependence(computeDependence(this));
 }
 
-PredefinedExpr::PredefinedExpr(SourceLocation L, QualType FnTy, IdentKind IK,
-                               TypeSourceInfo *Info)
-    : Expr(PredefinedExprClass, FnTy, VK_LValue, OK_Ordinary) {
-  PredefinedExprBits.Kind = IK;
-  assert((getIdentKind() == IK) &&
-         "IdentKind do not fit in PredefinedExprBitFields!");
-  assert(IK == UniqueStableNameType &&
-         "Constructor only valid with UniqueStableNameType");
-  PredefinedExprBits.HasFunctionName = false;
-  PredefinedExprBits.Loc = L;
-  setTypeSourceInfo(Info);
-  setDependence(computeDependence(this));
-}
-
-PredefinedExpr::PredefinedExpr(SourceLocation L, QualType FnTy, IdentKind IK,
-                               Expr *E)
-    : Expr(PredefinedExprClass, FnTy, VK_LValue, OK_Ordinary) {
-  PredefinedExprBits.Kind = IK;
-  assert((getIdentKind() == IK) &&
-         "IdentKind do not fit in PredefinedExprBitFields!");
-  assert(IK == UniqueStableNameExpr &&
-         "Constructor only valid with UniqueStableNameExpr");
-  PredefinedExprBits.HasFunctionName = false;
-  PredefinedExprBits.Loc = L;
-  setExpr(E);
-  setDependence(computeDependence(this));
-}
-
 PredefinedExpr::PredefinedExpr(EmptyShell Empty, bool HasFunctionName)
     : Expr(PredefinedExprClass, Empty) {
   PredefinedExprBits.HasFunctionName = HasFunctionName;
@@ -555,44 +527,15 @@ PredefinedExpr *PredefinedExpr::Create(const ASTContext &Ctx, SourceLocation L,
                                        QualType FNTy, IdentKind IK,
                                        StringLiteral *SL) {
   bool HasFunctionName = SL != nullptr;
-  void *Mem = Ctx.Allocate(
-      totalSizeToAlloc<Stmt *, Expr *, TypeSourceInfo *>(HasFunctionName, 0, 0),
-      alignof(PredefinedExpr));
-  return new (Mem) PredefinedExpr(L, FNTy, IK, SL);
-}
-
-PredefinedExpr *PredefinedExpr::Create(const ASTContext &Ctx, SourceLocation L,
-                                       QualType FNTy, IdentKind IK,
-                                       StringLiteral *SL,
-                                       TypeSourceInfo *Info) {
-  assert(IK == UniqueStableNameType && "Only valid with UniqueStableNameType");
-  bool HasFunctionName = SL != nullptr;
-  void *Mem = Ctx.Allocate(totalSizeToAlloc<Stmt *, Expr *, TypeSourceInfo *>(
-                               HasFunctionName, 0, !HasFunctionName),
-                           alignof(PredefinedExpr));
-  if (HasFunctionName)
-    return new (Mem) PredefinedExpr(L, FNTy, IK, SL);
-  return new (Mem) PredefinedExpr(L, FNTy, IK, Info);
-}
-
-PredefinedExpr *PredefinedExpr::Create(const ASTContext &Ctx, SourceLocation L,
-                                       QualType FNTy, IdentKind IK,
-                                       StringLiteral *SL, Expr *E) {
-  assert(IK == UniqueStableNameExpr && "Only valid with UniqueStableNameExpr");
-  bool HasFunctionName = SL != nullptr;
-  void *Mem = Ctx.Allocate(totalSizeToAlloc<Stmt *, Expr *, TypeSourceInfo *>(
-                               HasFunctionName, !HasFunctionName, 0),
+  void *Mem = Ctx.Allocate(totalSizeToAlloc<Stmt *>(HasFunctionName),
                            alignof(PredefinedExpr));
-  if (HasFunctionName)
-    return new (Mem) PredefinedExpr(L, FNTy, IK, SL);
-  return new (Mem) PredefinedExpr(L, FNTy, IK, E);
+  return new (Mem) PredefinedExpr(L, FNTy, IK, SL);
 }
 
 PredefinedExpr *PredefinedExpr::CreateEmpty(const ASTContext &Ctx,
                                             bool HasFunctionName) {
-  void *Mem = Ctx.Allocate(
-      totalSizeToAlloc<Stmt *, Expr *, TypeSourceInfo *>(HasFunctionName, 0, 0),
-      alignof(PredefinedExpr));
+  void *Mem = Ctx.Allocate(totalSizeToAlloc<Stmt *>(HasFunctionName),
+                           alignof(PredefinedExpr));
   return new (Mem) PredefinedExpr(EmptyShell(), HasFunctionName);
 }
 
@@ -612,28 +555,12 @@ StringRef PredefinedExpr::getIdentKindName(PredefinedExpr::IdentKind IK) {
     return "__FUNCSIG__";
   case LFuncSig:
     return "L__FUNCSIG__";
-  case UniqueStableNameType:
-  case UniqueStableNameExpr:
-    return "__builtin_unique_stable_name";
   case PrettyFunctionNoVirtual:
     break;
   }
   llvm_unreachable("Unknown ident kind for PredefinedExpr");
 }
 
-std::string PredefinedExpr::ComputeName(ASTContext &Context, IdentKind IK,
-                                        QualType Ty) {
-  std::unique_ptr<MangleContext> Ctx{ItaniumMangleContext::create(
-      Context, Context.getDiagnostics(), /*IsUniqueNameMangler*/ true)};
-
-  Ty = Ty.getCanonicalType();
-
-  SmallString<256> Buffer;
-  llvm::raw_svector_ostream Out(Buffer);
-  Ctx->mangleTypeName(Ty, Out);
-  return std::string(Buffer.str());
-}
-
 // FIXME: Maybe this should use DeclPrinter with a special "print predefined
 // expr" policy instead.
 std::string PredefinedExpr::ComputeName(IdentKind IK, const Decl *CurrentDecl) {