[PATCH] Testsuite, LTO: silence warning to make test pass on Darwin

[PATCH] Testsuite, LTO: silence warning to make test pass on Darwin

[FX Coudert]

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Hi,

On darwin (both x86_64-apple-darwin and aarch64-apple-darwin) we see the following test failure:

FAIL: gcc.dg/lto/20091013-1 c_lto_20091013-1_2.o assemble, -fPIC -r -nostdlib -O2 -flto

which is due to this extra warning:

In function 'fontcmp',
    inlined from 'find_in_cache' at /tmp/gcc-darwin-arm64/gcc/testsuite/gcc.dg/lto/20091013-1_2.c:140:13,
    inlined from 'WineEngCreateFontInstance' at /tmp/gcc-darwin-arm64/gcc/testsuite/gcc.dg/lto/20091013-1_2.c:160:15:
/tmp/gcc-darwin-arm64/gcc/testsuite/gcc.dg/lto/20091013-1_2.c:107:8: warning: 'memcmp' specified bound 4 exceeds source size 0 [-Wst
ringop-overread]
/tmp/gcc-darwin-arm64/gcc/testsuite/gcc.dg/lto/20091013-1_2.c: In function 'WineEngCreateFontInstance':
/tmp/gcc-darwin-arm64/gcc/testsuite/gcc.dg/lto/20091013-1_2.c:66:20: note: source object allocated here

Now, the main file for the test has:

/* { dg-extra-ld-options "-flinker-output=nolto-rel -Wno-stringop-overread" } */

and I believe the intent of -Wno-stringop-overread is to silence this warning, but that only applies to the linker, and the warning on darwin is produced by the compiler (in addition to the linker). Adding the flag to the compilation of the source file makes the test pass on darwin.

OK to commit?
FX



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From 4aa64187fa35dcb9a23d66ef875cf1bab4937c55 Mon Sep 17 00:00:00 2001
From: Francois-Xavier Coudert <fxcoudert@gmail.com>
Date: Sun, 20 Aug 2023 12:17:50 +0200
Subject: [PATCH] Testsuite, LTO: silence warning to make test pass on Darwin

gcc/testsuite/ChangeLog:

	* gcc.dg/lto/20091013-1_2.c: Add -Wno-stringop-overread.
---
 gcc/testsuite/gcc.dg/lto/20091013-1_2.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/gcc/testsuite/gcc.dg/lto/20091013-1_2.c b/gcc/testsuite/gcc.dg/lto/20091013-1_2.c
index 1af49aa97b6..89caea868e6 100644
--- a/gcc/testsuite/gcc.dg/lto/20091013-1_2.c
+++ b/gcc/testsuite/gcc.dg/lto/20091013-1_2.c
@@ -1,3 +1,5 @@
+/* { dg-options "-Wno-stringop-overread" } */
+
 typedef struct HDC__ { int unused; } *HDC;
 typedef struct HFONT__ { int unused; } *HFONT;
 
-- 
2.39.2 (Apple Git-143)

Re: [PATCH] Testsuite, LTO: silence warning to make test pass on Darwin

[Richard Biener]

On Sun, Aug 20, 2023 at 12:24 PM FX Coudert via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Hi,
>
> On darwin (both x86_64-apple-darwin and aarch64-apple-darwin) we see the following test failure:
>
> FAIL: gcc.dg/lto/20091013-1 c_lto_20091013-1_2.o assemble, -fPIC -r -nostdlib -O2 -flto
>
> which is due to this extra warning:
>
> In function 'fontcmp',
>     inlined from 'find_in_cache' at /tmp/gcc-darwin-arm64/gcc/testsuite/gcc.dg/lto/20091013-1_2.c:140:13,
>     inlined from 'WineEngCreateFontInstance' at /tmp/gcc-darwin-arm64/gcc/testsuite/gcc.dg/lto/20091013-1_2.c:160:15:
> /tmp/gcc-darwin-arm64/gcc/testsuite/gcc.dg/lto/20091013-1_2.c:107:8: warning: 'memcmp' specified bound 4 exceeds source size 0 [-Wst
> ringop-overread]
> /tmp/gcc-darwin-arm64/gcc/testsuite/gcc.dg/lto/20091013-1_2.c: In function 'WineEngCreateFontInstance':
> /tmp/gcc-darwin-arm64/gcc/testsuite/gcc.dg/lto/20091013-1_2.c:66:20: note: source object allocated here
>
> Now, the main file for the test has:
>
> /* { dg-extra-ld-options "-flinker-output=nolto-rel -Wno-stringop-overread" } */
>
> and I believe the intent of -Wno-stringop-overread is to silence this warning, but that only applies to the linker, and the warning on darwin is produced by the compiler (in addition to the linker). Adding the flag to the compilation of the source file makes the test pass on darwin.

In the end this is because darwin is -ffat-lto-objects and not using
the linker plugin(?)

> OK to commit?

OK.

Thanks,
Richard.

> FX
>
>