Implement C++0x user-defined string literals.

The extra data stored on user-defined literal Tokens is stored in extra
allocated memory, which is managed by the PreprocessorLexer because there isn't
a better place to put it that makes sure it gets deallocated, but only after
it's used up. My testing has shown no significant slowdown as a result, but
independent testing would be appreciated.

llvm-svn: 112458

1 files changed, 58 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 5720d931b66..344196cc6ff 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -3057,3 +3057,61 @@ ExprResult Sema::ActOnFinishFullExpr(Expr *FullExpr) {
   if (!FullExpr) return ExprError();
   return MaybeCreateCXXExprWithTemporaries(FullExpr);
 }
+
+ExprResult Sema::BuildUDStringLiteralExpr(Scope *S, StringLiteral *SL,
+                                          unsigned L, IdentifierInfo *II) {
+  DeclarationName DN = Context.DeclarationNames.getCXXLiteralOperatorName(II);
+
+  LookupResult R(*this, DN, SL->getLocStart(),  LookupOrdinaryName);
+  LookupName(R, S);
+
+  llvm::APInt APL(Context.getTypeSize(Context.getSizeType()), L);
+
+  Expr *Args[2];
+  Args[0] = SL;
+  Args[1] = new (Context) IntegerLiteral(Context, APL, Context.getSizeType(),
+                                         SourceLocation());
+
+  OverloadCandidateSet CandidateSet(SL->getLocStart());
+  AddFunctionCandidates(R.asUnresolvedSet(), Args, 2, CandidateSet);
+  OverloadCandidateSet::iterator Best;
+  switch (CandidateSet.BestViableFunction(*this, SL->getLocStart(), Best)) {
+    case OR_Ambiguous:
+      llvm_unreachable("UD literals should not have ambiguous overloads");
+      return ExprError();
+    case OR_No_Viable_Function:
+      Diag(SL->getLocStart(), diag::err_literal_operator_overload)
+        << SL->getSourceRange() << II->getName();
+      return ExprError();
+    case OR_Deleted:
+      Diag(SL->getLocStart(), diag::err_literal_operator_deleted)
+        << SL->getSourceRange() << II->getName();
+      //FIXME: Note the deleted function
+      return ExprError();
+    case OR_Success:
+      break;
+  }
+
+  assert(Best->Function && "Literal operator function not a real function");
+  FunctionDecl *FD = Best->Function;
+
+  ExprResult InputInit
+    = PerformCopyInitialization(InitializedEntity::InitializeParameter(
+                                                   FD->getParamDecl(0)),
+                                SourceLocation(), Owned(SL));
+  if (InputInit.isInvalid())
+    return ExprError();
+  Args[0] = InputInit.takeAs<Expr>();
+
+  QualType ResultTy = FD->getResultType().getNonReferenceType();
+  Expr *Fn = new (Context) DeclRefExpr(FD, FD->getType(), SourceLocation());
+  UsualUnaryConversions(Fn);
+
+  UDLiteralExpr *E = new (Context) UDLiteralExpr(Context, SL, Fn, Args, 2,
+                                                     ResultTy);
+
+  if (CheckCallReturnType(FD->getResultType(), SL->getLocStart(), E, FD))
+    return ExprError();
+
+  return MaybeBindToTemporary(E);
+}