c++: wrong error with constexpr COMPOUND_EXPR [PR105321]
Here we issue a bogus error for the first assert in the test. Therein
we have
<retval> = (void) (VIEW_CONVERT_EXPR<bool>(yes) || handle_error ());, VIEW_CONVERT_EXPR<int>(value);
which has a COMPOUND_EXPR, so we get to cxx_eval_constant_expression
<case COMPOUND_EXPR>. The problem here is that we call
7044 /* Check that the LHS is constant and then discard it. */
7045 cxx_eval_constant_expression (ctx, op0,
7046 true, non_constant_p, overflow_p,
7047 jump_target);
where lval is always true, so the PARM_DECL 'yes' is not evaluated into
its value.
Fixed by always passing false for 'lval' in cxx_eval_logical_expression;
there's no case where we actually expect an lvalue from a TRUTH_*.
PR c++/105321
gcc/cp/ChangeLog:
* constexpr.cc (cxx_eval_logical_expression): Always pass false for lval
to cxx_eval_constant_expression.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/constexpr-105321.C: New test.