Re: Fix build of jit (was Re: [PATCH, RFC] Introduce -fsanitize=use-after-scope (v3))

[Jakub Jelinek <jakub@redhat.com>]

On Mon, Nov 07, 2016 at 11:07:13AM -0500, David Malcolm wrote:
> The patch (r241896) introduced an error in the build of the jit:
> 
> ../../src/gcc/jit/jit-builtins.c:62:1: error: invalid conversion from
> ‘int’ to ‘gcc::jit::built_in_attribute’ [-fpermissive]
>  };
>  ^
> 
> which seems to be due to the "0" for ATTRS in:
> 
> --- a/gcc/sanitizer.def
> +++ b/gcc/sanitizer.def
> @@ -165,6 +165,10 @@ DEF_SANITIZER_BUILTIN(BUILT_IN_ASAN_BEFORE_DYNAMIC_INIT,
>  DEF_SANITIZER_BUILTIN(BUILT_IN_ASAN_AFTER_DYNAMIC_INIT,
>  		      "__asan_after_dynamic_init",
>  		      BT_FN_VOID, ATTR_NOTHROW_LEAF_LIST)
> +DEF_SANITIZER_BUILTIN(BUILT_IN_ASAN_CLOBBER_N, "__asan_poison_stack_memory",
> +		      BT_FN_VOID_PTR_PTRMODE, 0)
> +DEF_SANITIZER_BUILTIN(BUILT_IN_ASAN_UNCLOBBER_N, "__asan_unpoison_stack_memory",
> +		      BT_FN_VOID_PTR_PTRMODE, 0)

I believe the 0 here is a bug, I'd think we should be using something like
ATTR_TMPURE_NOTHROW_LEAF_LIST that we are using __asan_load* - the functions
aren't going to throw, nor call anything in the current TU.  Not 100% sure
about the TMPURE, after all they do write/read memory (the shadow one).
So maybe ATTR_NOTHROW_LEAF_LIST instead for now?  Martin?

> Is the attached patch OK as a fix? (assuming testing passes)  Or should
> these builtins have other attrs?  (sorry, am not very familiar with the
> sanitizer code).

	Jakub