On Mon, 4 Mar 2019, Jakub Jelinek wrote:
> Hi!
>
> Before PR87041 changes sprintf_dom_walker::handle_gimple_call
> would punt if gimple_call_builtin_p (which did all the needed call argument
> checking) failed, but it doesn't fail anymore because it wants to handle
> format attribute. That is fine, but if gimple_call_builtin_p failed, we
> shouldn't handle them as builtins, just possibly as format string argument
> functions. Note, info.func might be even backend or FE builtin and
> DECL_FUNCTION_CODE in those cases means something completely different
> anyway.
>
> So, the following patch makes sure to only set info.fncode if
> gimple_call_builtin_p succeeds, and for format attribute does at least
> minimal verification, that the call actually has an argument at idx_format
> position which also has a pointer-ish type, and that idx_args isn't out of
> bounds either (that one can be equal to number of arguments, that represents
> zero varargs arguments).
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
Richard.
> 2019-03-04 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/89566
> * gimple-ssa-sprintf.c (sprintf_dom_walker::handle_gimple_call):
> Set info.fncode to BUILT_IN_NONE if gimple_call_builtin_p failed.
> Punt if get_user_idx_format succeeds, but idx_format argument is
> not provided or doesn't have pointer type, or if idx_args is above
> number of provided arguments.
>
> * c-c++-common/pr89566.c: New test.
>
> --- gcc/gimple-ssa-sprintf.c.jj 2019-02-24 20:18:01.348754080 +0100
> +++ gcc/gimple-ssa-sprintf.c 2019-03-04 10:52:32.867295908 +0100
> @@ -3858,16 +3858,21 @@ sprintf_dom_walker::handle_gimple_call (
> if (!info.func)
> return false;
>
> - info.fncode = DECL_FUNCTION_CODE (info.func);
> -
> /* Format string argument number (valid for all functions). */
> unsigned idx_format = UINT_MAX;
> - if (!gimple_call_builtin_p (info.callstmt, BUILT_IN_NORMAL))
> + if (gimple_call_builtin_p (info.callstmt, BUILT_IN_NORMAL))
> + info.fncode = DECL_FUNCTION_CODE (info.func);
> + else
> {
> unsigned idx_args;
> idx_format = get_user_idx_format (info.func, &idx_args);
> - if (idx_format == UINT_MAX)
> + if (idx_format == UINT_MAX
> + || idx_format >= gimple_call_num_args (info.callstmt)
> + || idx_args > gimple_call_num_args (info.callstmt)
> + || !POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (info.callstmt,
> + idx_format))))
> return false;
> + info.fncode = BUILT_IN_NONE;
> info.argidx = idx_args;
> }
>
> --- gcc/testsuite/c-c++-common/pr89566.c.jj 2019-03-04 10:56:10.060730886
> +0100
> +++ gcc/testsuite/c-c++-common/pr89566.c 2019-03-04 10:55:54.334989014
> +0100
> @@ -0,0 +1,15 @@
> +/* PR tree-optimization/89566 */
> +/* { dg-do compile } */
> +
> +typedef struct FILE { int i; } FILE;
> +#ifdef __cplusplus
> +extern "C"
> +#endif
> +int fprintf (FILE *, const char *, ...);
> +
> +int
> +main ()
> +{
> + ((void (*)()) fprintf) (); // { dg-warning "function called through a
> non-compatible type" "" { target c } }
> + return 0;
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
