On 20 Sep 2012, at 08:51, "Zhenqiang Chen" <zhenqiang.c...@linaro.org> wrote:
> Hi,
>
> PR 50970 is a general c++ front-end issue for targets which define
> TARGET_PTRMEMFUNC_VBIT_LOCATION ptrmemfunc_vbit_in_delta, although the
> reporter had issues only on ARM.
>
> Root cause: It misses a check for side effects when generating pfn and
> delta related expressions.
>
> In the failed case, op0 is a function call. pfn0 and delta0 are
> expressions based on the return value of op0. Without the check, the
> function will be called twice.
>
> The patch is to add the check for op0.
>
> No make check regression on ARM.
>
> Is it OK for trunk?
>
> Thanks!
> -Zhenqiang
>
> cp/ChangeLog:
> 2012-09-20 Zhenqiang Chen <zhenqiang.c...@linaro.org>
>
> PR c++/50970
> * typeck.c (cp_build_binary_op): Check side effects before generating
> pfn and delta related expressions.
>
Ok.
R.
> diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
> index ad4b090..884f7d0 100644
> --- a/gcc/cp/typeck.c
> +++ b/gcc/cp/typeck.c
> @@ -4159,18 +4159,23 @@ cp_build_binary_op (location_t location,
> if (TARGET_PTRMEMFUNC_VBIT_LOCATION
> == ptrmemfunc_vbit_in_delta)
> {
> - tree pfn0 = pfn_from_ptrmemfunc (op0);
> - tree delta0 = delta_from_ptrmemfunc (op0);
> - tree e1 = cp_build_binary_op (location,
> - EQ_EXPR,
> - pfn0,
> - build_zero_cst (TREE_TYPE (pfn0)),
> - complain);
> - tree e2 = cp_build_binary_op (location,
> - BIT_AND_EXPR,
> - delta0,
> - integer_one_node,
> - complain);
> + tree pfn0, delta0, e1, e2;
> +
> + if (TREE_SIDE_EFFECTS (op0))
> + op0 = save_expr (op0);
> +
> + pfn0 = pfn_from_ptrmemfunc (op0);
> + delta0 = delta_from_ptrmemfunc (op0);
> + e1 = cp_build_binary_op (location,
> + EQ_EXPR,
> + pfn0,
> + build_zero_cst (TREE_TYPE (pfn0)),
> + complain);
> + e2 = cp_build_binary_op (location,
> + BIT_AND_EXPR,
> + delta0,
> + integer_one_node,
> + complain);
>
> if ((complain & tf_warning)
> && c_inhibit_evaluation_warnings == 0
>
