diff options
| -rw-r--r-- | lib/AST/Expr.cpp | 12 | ||||
| -rw-r--r-- | test/Sema/warn-unused-value.c | 9 |
2 files changed, 16 insertions, 5 deletions
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp index 8e44c07368..930457c249 100644 --- a/lib/AST/Expr.cpp +++ b/lib/AST/Expr.cpp @@ -1404,13 +1404,15 @@ bool Expr::isUnusedResultAWarning(SourceLocation &Loc, SourceRange &R1, return false; case ConditionalOperatorClass: { - // The condition must be evaluated, but if either the LHS or RHS is a - // warning, warn about them. + // 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<ConditionalOperator>(this); - if (Exp->getLHS() && - Exp->getLHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx)) + if (!Exp->getRHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx)) + return false; + if (!Exp->getLHS()) return true; - return Exp->getRHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx); + return Exp->getLHS()->isUnusedResultAWarning(Loc, R1, R2, Ctx); } case MemberExprClass: diff --git a/test/Sema/warn-unused-value.c b/test/Sema/warn-unused-value.c index 876eb9e482..95cd8fb704 100644 --- a/test/Sema/warn-unused-value.c +++ b/test/Sema/warn-unused-value.c @@ -72,6 +72,15 @@ int test_logical_bar() { return x; } +// PR8282 +void conditional_for_control_flow(int cond, int x, int y) +{ + cond? y++ : x; // no-warning + cond? y : ++x; // no-warning + cond? (x |= y) : ++x; // no-warning + cond? y : x; // expected-warning {{expression result unused}} +} + struct s0 { int f0; }; void f0(int a); |