On Fri, 29 Oct 2021, Jakub Jelinek wrote:
> Hi!
>
> As mentioned yesterday, gimple_fold_builtin_memset doesn't preserve
> locus which means e.g. the -Wstringop-overflow warnings are emitted as:
> In function 'test_max':
> cc1: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
> The function emits up to 2 new statements, but the latter (asgn) is added
> through gsi_replace and therefore the locus is copied over from the call.
> But store is emitted before the call and optionally the call removed
> afterwards, so locus needs to be copied over manually.
>
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
> trunk?
OK.
Thanks,
Richard.
> 2021-10-29 Jakub Jelinek <ja...@redhat.com>
>
> * gimple-fold.c (gimple_fold_builtin_memset): Copy over location from
> call to store.
>
> * gcc.dg/Wstringop-overflow-62.c: Adjust expected diagnostics.
>
> --- gcc/gimple-fold.c.jj 2021-10-12 09:36:57.728450483 +0200
> +++ gcc/gimple-fold.c 2021-10-28 12:42:07.638741783 +0200
> @@ -1505,6 +1505,7 @@ gimple_fold_builtin_memset (gimple_stmt_
> var = fold_build2 (MEM_REF, etype, dest, build_int_cst (ptr_type_node, 0));
> gimple *store = gimple_build_assign (var, build_int_cst_type (etype,
> cval));
> gimple_move_vops (store, stmt);
> + gimple_set_location (store, gimple_location (stmt));
> gsi_insert_before (gsi, store, GSI_SAME_STMT);
> if (gimple_call_lhs (stmt))
> {
> --- gcc/testsuite/gcc.dg/Wstringop-overflow-62.c.jj 2021-10-28
> 12:24:21.909780099 +0200
> +++ gcc/testsuite/gcc.dg/Wstringop-overflow-62.c 2021-10-28
> 12:43:52.023273297 +0200
> @@ -223,7 +223,7 @@ void test_max (void)
>
> char *q = MAX (pi, pj);
>
> - memset (q, 0, 1); // { dg-warning "writing 1 byte into a region
> of size 0 " "" { target *-*-* } 0 }
> + memset (q, 0, 1); // { dg-warning "writing 1 byte into a region
> of size 0 " }
> memset (q, 0, 2); // { dg-warning "writing 2 bytes into a region
> of size 0 " }
> }
>
> @@ -345,7 +345,7 @@ void test_max (void)
> not reflected in the determaxed offset). */
> char *q = MAX (p1, p2);
>
> - memset (q, 0, 1);
> + memset (q, 0, 1); // { dg-warning "writing 1 byte into a region
> of size 0 " }
> }
>
> {
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
