From 6d31563422387be311f5fd2794fc67c5e9f11d66 Mon Sep 17 00:00:00 2001 From: Nathan Huckleberry Date: Wed, 19 Jun 2019 18:37:01 +0000 Subject: [PATCH] [AST] Fixed extraneous warnings for binary conditional operator Summary: Binary conditional operator gave warnings where ternary operators did not. They have been fixed to warn similarly to ternary operators. Link: https://bugs.llvm.org/show_bug.cgi?id=42239 Reviewers: rsmith, aaron.ballman, nickdesaulniers Reviewed By: rsmith, nickdesaulniers Subscribers: srhines, cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D63369 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@363857 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/AST/Expr.cpp | 13 +++++++------ .../warn-binary-conditional-expression-unused.c | 15 +++++++++++++++ 2 files changed, 22 insertions(+), 6 deletions(-) create mode 100644 test/Sema/warn-binary-conditional-expression-unused.c diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp index f5714d9378..cc92689cb9 100644 --- a/lib/AST/Expr.cpp +++ b/lib/AST/Expr.cpp @@ -2453,12 +2453,13 @@ bool Expr::isUnusedResultAWarning(const Expr *&WarnE, SourceLocation &Loc, // If only one of the LHS or RHS is a warning, the operator might // be being used for control flow. Only warn if both the LHS and // RHS are warnings. - const ConditionalOperator *Exp = cast(this); - if (!Exp->getRHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx)) - return false; - if (!Exp->getLHS()) - return true; - return Exp->getLHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx); + const auto *Exp = cast(this); + return Exp->getLHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx) && + Exp->getRHS()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx); + } + case BinaryConditionalOperatorClass: { + const auto *Exp = cast(this); + return Exp->getFalseExpr()->isUnusedResultAWarning(WarnE, Loc, R1, R2, Ctx); } case MemberExprClass: diff --git a/test/Sema/warn-binary-conditional-expression-unused.c b/test/Sema/warn-binary-conditional-expression-unused.c new file mode 100644 index 0000000000..982d66df6d --- /dev/null +++ b/test/Sema/warn-binary-conditional-expression-unused.c @@ -0,0 +1,15 @@ +// RUN: %clang_cc1 -fsyntax-only -Wunused-value -verify %s +int main() { + int a; + int b; + a ? : b; //expected-warning{{expression result unused}} + a ? a : b; //expected-warning{{expression result unused}} + a ? : ++b; + a ? a : ++b; + ++a ? : b; //expected-warning{{expression result unused}} + ++a ? a : b; //expected-warning{{expression result unused}} + ++a ? : ++b; + ++a ? a : ++b; + return 0; +}; + -- 2.40.0