From: Fangrui Song <i@maskray.me>
To: Jan Beulich <jbeulich@suse.com>
Cc: binutils@sourceware.org, Alan Modra <amodra@gmail.com>,
Nick Clifton <nickc@redhat.com>
Subject: Re: [PATCH] gas: copy st_size only if unset
Date: Thu, 31 Mar 2022 18:33:43 -0700 [thread overview]
Message-ID: <20220401013343.jeb5ptalaumk7cdq@gmail.com> (raw)
In-Reply-To: <2b2801ff-0bc4-2680-2526-74dd87be3ea0@suse.com>
On 2022-03-31, Jan Beulich wrote:
>On 31.03.2022 05:37, Fangrui Song wrote:
>> For
>> ```
>> .size foo1, 1
>> foo1:
>>
>> .set bar1, foo1
>> .size bar1, 2
>> .size bar2, 2
>> .set bar2, foo1
>>
>> .set bar3, foo2
>> .size bar3, 2
>> .size bar4, 2
>> .set bar4, foo2
>>
>> .size foo2, 1
>> foo2:
>> ```
>>
>> bar1's size is 2 while bar2, bar3, bar4's is 1. The behavior of bar1 makes sense
>> (generally directives on the new symbol should win) and is relied upon by glibc
>> stdio-common/errlist.c:
>
>But what about
>
>foo1:
> .size foo1, 1
>foo2:
> .size foo2, 2
> .set bar, foo1
> .set bar, foo2
>
>I would think bar's size should end up being 2 in this case, whereas I
>think it would end up being 1 with your change.
>
>Jan
bar's size is 2. The patch has no effect, because `dest` variables for the two
invocations are (surprisingly) different!
bar is a volatile symbol (created by .set instead of .equiv). The
second .set directive creates calls gas.c/read.c:3273 symbol_clone (symbolP, 1).
That said, I think it makes sense to add tests for this as well.
I'll use the following if this patch is accepted.
.text
.size foo1, 1
foo1:
.set bar1, foo1
.size bar1, 2
.size bar2, 2
.set bar2, foo1
.set bar3, foo2
.size bar3, 2
.size bar4, 2
.set bar4, foo2
.set bar5, foo1
.set bar6, foo2
.size foo2, 3
foo2:
.set bar7, foo1
.set bar7, foo2
next prev parent reply other threads:[~2022-04-01 1:33 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-31 3:37 Fangrui Song
2022-03-31 6:22 ` Jan Beulich
2022-04-01 1:33 ` Fangrui Song [this message]
2022-04-04 11:27 ` Jan Beulich
2022-04-08 7:42 ` Alan Modra
2022-04-08 21:26 ` Fangrui Song
2022-04-08 23:01 ` Fangrui Song
2022-04-08 23:06 ` Fangrui Song
2022-04-09 1:12 ` Alan Modra
2022-04-09 0:43 ` Alan Modra
2022-04-09 4:29 ` Jeff Law
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