On Thu, Mar 20, 2014 at 12:45 PM, Marek Polacek <pola...@redhat.com> wrote:
> On Thu, Mar 20, 2014 at 12:10:35PM +0100, Richard Biener wrote:
>> On Thu, Mar 20, 2014 at 12:07 PM, Marek Polacek <pola...@redhat.com> wrote:
>> > We should warn if someone wants to use both always_inline and noinline
>> > attributes.
>> >
>> > Regtested/bootstrapped on x86_64-linux. This is hardly 4.9 material,
>> > so ok for 5.0?
>>
>> Shouldn't the warning state that the attribute will be ignored? That is,
>> the common warning is
>>
>> warning (OPT_Wattributes, "%qE attribute ignored", name);
>>
>> which could be amended with " due to conflict with ....".
>
> Dunno. I did what we do wrt conflicting cold/hot attributes. But
> here's a patch with what you suggest (with some Extra Quotes).
That works for me, please let Joseph some time to comment.
The "%qE attribute conflicts with attribute %s" way leaves me out in
the dark on what attribute will be in effect for the decl - it could be
either or none as far as I read it. Or even both, with unspecified
behavior.
Richard.
> 2014-03-20 Marek Polacek <pola...@redhat.com>
>
> PR c/18079
> c-family/
> * c-common.c (handle_noinline_attribute): Warn if the attribute
> conflicts with always_inline attribute.
> (handle_always_inline_attribute): Warn if the attribute conflicts
> with noinline attribute.
> testsuite/
> * gcc.dg/pr18079.c: New test.
>
> diff --git gcc/c-family/c-common.c gcc/c-family/c-common.c
> index abd96fb..5258e52 100644
> --- gcc/c-family/c-common.c
> +++ gcc/c-family/c-common.c
> @@ -6666,7 +6666,16 @@ handle_noinline_attribute (tree *node, tree name,
> int ARG_UNUSED (flags), bool *no_add_attrs)
> {
> if (TREE_CODE (*node) == FUNCTION_DECL)
> - DECL_UNINLINABLE (*node) = 1;
> + {
> + if (lookup_attribute ("always_inline", DECL_ATTRIBUTES (*node)))
> + {
> + warning (OPT_Wattributes, "%qE attribute ignored due to conflict "
> + "with %<always_inline%> attribute", name);
> + *no_add_attrs = true;
> + }
> + else
> + DECL_UNINLINABLE (*node) = 1;
> + }
> else
> {
> warning (OPT_Wattributes, "%qE attribute ignored", name);
> @@ -6704,9 +6713,16 @@ handle_always_inline_attribute (tree *node, tree name,
> {
> if (TREE_CODE (*node) == FUNCTION_DECL)
> {
> - /* Set the attribute and mark it for disregarding inline
> - limits. */
> - DECL_DISREGARD_INLINE_LIMITS (*node) = 1;
> + if (lookup_attribute ("noinline", DECL_ATTRIBUTES (*node)))
> + {
> + warning (OPT_Wattributes, "%qE attribute ignored due to conflict "
> + "with %<noinline%> attribute", name);
> + *no_add_attrs = true;
> + }
> + else
> + /* Set the attribute and mark it for disregarding inline
> + limits. */
> + DECL_DISREGARD_INLINE_LIMITS (*node) = 1;
> }
> else
> {
> diff --git gcc/testsuite/gcc.dg/pr18079.c gcc/testsuite/gcc.dg/pr18079.c
> index e69de29..b84cdeb 100644
> --- gcc/testsuite/gcc.dg/pr18079.c
> +++ gcc/testsuite/gcc.dg/pr18079.c
> @@ -0,0 +1,33 @@
> +/* PR c/18079 */
> +/* { dg-do compile } */
> +/* { dg-options "-Wall" } */
> +
> +__attribute__ ((noinline))
> +__attribute__ ((always_inline))
> +int
> +fn1 (int r)
> +{ /* { dg-warning "attribute ignored due to conflict" } */
> + return r & 4;
> +}
> +
> +__attribute__ ((noinline, always_inline))
> +int
> +fn2 (int r)
> +{ /* { dg-warning "attribute ignored due to conflict" } */
> + return r & 4;
> +}
> +
> +__attribute__ ((always_inline))
> +__attribute__ ((noinline))
> +inline int
> +fn3 (int r)
> +{ /* { dg-warning "attribute ignored due to conflict" } */
> + return r & 8;
> +}
> +
> +__attribute__ ((always_inline, noinline))
> +inline int
> +fn4 (int r)
> +{ /* { dg-warning "attribute ignored due to conflict" } */
> + return r & 8;
> +}
>
> Marek
