From ea5fc1e6b74132df717aa0a1f1cbfd87643ab234 Mon Sep 17 00:00:00 2001 From: Richard Smith Date: Wed, 15 Feb 2017 19:57:10 +0000 Subject: [PATCH] PR24440: Do not silently discard a fold-expression appearing as the operand of a cast-expression. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@295224 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Parse/ParseExpr.cpp | 2 +- lib/Sema/SemaTemplateVariadic.cpp | 7 +++++++ test/Parser/cxx1z-fold-expressions.cpp | 9 +++++++++ 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/lib/Parse/ParseExpr.cpp b/lib/Parse/ParseExpr.cpp index 0c09614547..56c7685d93 100644 --- a/lib/Parse/ParseExpr.cpp +++ b/lib/Parse/ParseExpr.cpp @@ -2409,7 +2409,7 @@ Parser::ParseParenExpression(ParenParseOption &ExprType, bool stopIfCastExpr, // fold-expressions, we'll need to allow multiple ArgExprs here. if (ArgExprs.size() == 1 && isFoldOperator(Tok.getKind()) && NextToken().is(tok::ellipsis)) - return ParseFoldExpression(Result, T); + return ParseFoldExpression(ArgExprs[0], T); ExprType = SimpleExpr; Result = Actions.ActOnParenListExpr(OpenLoc, Tok.getLocation(), diff --git a/lib/Sema/SemaTemplateVariadic.cpp b/lib/Sema/SemaTemplateVariadic.cpp index 4ea04ac143..9f572007d8 100644 --- a/lib/Sema/SemaTemplateVariadic.cpp +++ b/lib/Sema/SemaTemplateVariadic.cpp @@ -1015,6 +1015,11 @@ ExprResult Sema::ActOnCXXFoldExpr(SourceLocation LParenLoc, Expr *LHS, CheckFoldOperand(*this, LHS); CheckFoldOperand(*this, RHS); + auto DiscardOperands = [&] { + CorrectDelayedTyposInExpr(LHS); + CorrectDelayedTyposInExpr(RHS); + }; + // [expr.prim.fold]p3: // In a binary fold, op1 and op2 shall be the same fold-operator, and // either e1 shall contain an unexpanded parameter pack or e2 shall contain @@ -1022,6 +1027,7 @@ ExprResult Sema::ActOnCXXFoldExpr(SourceLocation LParenLoc, Expr *LHS, if (LHS && RHS && LHS->containsUnexpandedParameterPack() == RHS->containsUnexpandedParameterPack()) { + DiscardOperands(); return Diag(EllipsisLoc, LHS->containsUnexpandedParameterPack() ? diag::err_fold_expression_packs_both_sides @@ -1035,6 +1041,7 @@ ExprResult Sema::ActOnCXXFoldExpr(SourceLocation LParenLoc, Expr *LHS, if (!LHS || !RHS) { Expr *Pack = LHS ? LHS : RHS; assert(Pack && "fold expression with neither LHS nor RHS"); + DiscardOperands(); if (!Pack->containsUnexpandedParameterPack()) return Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs) << Pack->getSourceRange(); diff --git a/test/Parser/cxx1z-fold-expressions.cpp b/test/Parser/cxx1z-fold-expressions.cpp index 0306385832..b1f7318e41 100644 --- a/test/Parser/cxx1z-fold-expressions.cpp +++ b/test/Parser/cxx1z-fold-expressions.cpp @@ -34,3 +34,12 @@ template int bad9() { return (3 + ... * N); } // expected-error {{oper template int bad10() { return (3 ? ... : N); } // expected-error +{{}} expected-note {{to match}} template int bad11() { return (N + ... 0); } // expected-error {{expected a foldable binary operator}} expected-error {{expected expression}} template int bad12() { return (... N); } // expected-error {{expected expression}} + +template void as_operand_of_cast(int a, T ...t) { + return + (int)(a + ... + undeclared_junk) + // expected-error {{undeclared}} expected-error {{does not contain any unexpanded}} + (int)(t + ... + undeclared_junk) + // expected-error {{undeclared}} + (int)(... + undeclared_junk) + // expected-error {{undeclared}} expected-error {{does not contain any unexpanded}} + (int)(undeclared_junk + ...) + // expected-error {{undeclared}} + (int)(a + ...); // expected-error {{does not contain any unexpanded}} +} -- 2.40.0