PR c/23113
* stmt.c (warn_if_unused_value): Check TREE_NO_WARNING at start.
Don't handle NOP_EXPR, CONVERT_EXPR and NON_LVALUE_EXPR
specially. Check for side effects only for COND_EXPR.
* c-typeck.c (c_finish_stmt_expr): Mark statement expression
return with TREE_NO_WARNING.
testsuite:
* gcc.dg/Wunused-value-1.c: New test.
From-SVN: r102805
Joseph Myers