Implement template instantiation for the prefix unary operators. As

always, refactored the existing logic to tease apart the parser action
and the semantic analysis shared by the parser and template
instantiation.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@66987 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 149 insertions, 1 deletions

diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 865034707d..8943aa602e 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -3623,6 +3623,153 @@ FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee,
   return 0;
 }
 
+/// \brief Create a unary operation that may resolve to an overloaded
+/// operator.
+///
+/// \param OpLoc The location of the operator itself (e.g., '*').
+///
+/// \param OpcIn The UnaryOperator::Opcode that describes this
+/// operator.
+///
+/// \param Functions The set of non-member functions that will be
+/// considered by overload resolution. The caller needs to build this
+/// set based on the context using, e.g.,
+/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This
+/// set should not contain any member functions; those will be added
+/// by CreateOverloadedUnaryOp().
+///
+/// \param input The input argument.
+Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc,
+                                                     unsigned OpcIn,
+                                                     FunctionSet &Functions,
+                                                     ExprArg input) {  
+  UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn);
+  Expr *Input = (Expr *)input.get();
+
+  OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc);
+  assert(Op != OO_None && "Invalid opcode for overloaded unary operator");
+  DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
+
+  Expr *Args[2] = { Input, 0 };
+  unsigned NumArgs = 1;
+    
+  // For post-increment and post-decrement, add the implicit '0' as
+  // the second argument, so that we know this is a post-increment or
+  // post-decrement.
+  if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) {
+    llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false);
+    Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 
+                                           SourceLocation());
+    NumArgs = 2;
+  }
+
+  if (Input->isTypeDependent()) {
+    OverloadedFunctionDecl *Overloads 
+      = OverloadedFunctionDecl::Create(Context, CurContext, OpName);
+    for (FunctionSet::iterator Func = Functions.begin(), 
+                            FuncEnd = Functions.end();
+         Func != FuncEnd; ++Func)
+      Overloads->addOverload(*Func);
+
+    DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy,
+                                                OpLoc, false, false);
+    
+    input.release();
+    return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn,
+                                                   &Args[0], NumArgs,
+                                                   Context.DependentTy,
+                                                   OpLoc));
+  }
+
+  // Build an empty overload set.
+  OverloadCandidateSet CandidateSet;
+
+  // Add the candidates from the given function set.
+  AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false);
+
+  // Add operator candidates that are member functions.
+  AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet);
+
+  // Add builtin operator candidates.
+  AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet);
+
+  // Perform overload resolution.
+  OverloadCandidateSet::iterator Best;
+  switch (BestViableFunction(CandidateSet, Best)) {
+  case OR_Success: {
+    // We found a built-in operator or an overloaded operator.
+    FunctionDecl *FnDecl = Best->Function;
+    
+    if (FnDecl) {
+      // We matched an overloaded operator. Build a call to that
+      // operator.
+      
+      // Convert the arguments.
+      if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
+        if (PerformObjectArgumentInitialization(Input, Method))
+          return ExprError();
+      } else {
+        // Convert the arguments.
+        if (PerformCopyInitialization(Input,
+                                      FnDecl->getParamDecl(0)->getType(),
+                                      "passing"))
+          return ExprError();
+      }
+
+      // Determine the result type
+      QualType ResultTy
+        = FnDecl->getType()->getAsFunctionType()->getResultType();
+      ResultTy = ResultTy.getNonReferenceType();
+      
+      // Build the actual expression node.
+      Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(),
+                                               SourceLocation());
+      UsualUnaryConversions(FnExpr);
+      
+      input.release();
+      return Owned(new (Context) CXXOperatorCallExpr(Context, Op, FnExpr,
+                                                     &Input, 1, ResultTy, 
+                                                     OpLoc));
+    } else {
+      // We matched a built-in operator. Convert the arguments, then
+      // break out so that we will build the appropriate built-in
+      // operator node.
+        if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0],
+                                      Best->Conversions[0], "passing"))
+          return ExprError();
+
+        break;
+      }
+    }
+
+    case OR_No_Viable_Function:
+      // No viable function; fall through to handling this as a
+      // built-in operator, which will produce an error message for us.
+      break;
+
+    case OR_Ambiguous:
+      Diag(OpLoc,  diag::err_ovl_ambiguous_oper)
+          << UnaryOperator::getOpcodeStr(Opc)
+          << Input->getSourceRange();
+      PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true);
+      return ExprError();
+
+    case OR_Deleted:
+      Diag(OpLoc, diag::err_ovl_deleted_oper)
+        << Best->Function->isDeleted()
+        << UnaryOperator::getOpcodeStr(Opc)
+        << Input->getSourceRange();
+      PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true);
+      return ExprError();
+    }
+
+  // Either we found no viable overloaded operator or we matched a
+  // built-in operator. In either case, fall through to trying to
+  // build a built-in operation.
+  input.release();
+  return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input));
+}
+
 /// \brief Create a binary operation that may resolve to an overloaded
 /// operator.
 ///
@@ -3645,7 +3792,6 @@ Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
                             unsigned OpcIn, 
                             FunctionSet &Functions,
                             Expr *LHS, Expr *RHS) {
-  OverloadCandidateSet CandidateSet;
   Expr *Args[2] = { LHS, RHS };
 
   BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn);
@@ -3688,6 +3834,8 @@ Sema::CreateOverloadedBinOp(SourceLocation OpLoc,
       !LHS->getType()->isOverloadableType())
     return CreateBuiltinBinOp(OpLoc, Opc, LHS, RHS);
 
+  // Build an empty overload set.
+  OverloadCandidateSet CandidateSet;
 
   // Add the candidates from the given function set.
   AddFunctionCandidates(Functions, Args, 2, CandidateSet, false);