musl - Question about flexible array

Follow @Openwall on Twitter for new release announcements and other news

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <1d4aed0c.7c9e.190243604d7.Coremail.fanpeng@loongson.cn>
Date: Mon, 17 Jun 2024 11:20:38 +0800 (GMT+08:00)
From: 樊鹏 <fanpeng@...ngson.cn>
To: "Rich Felker" <dalias@...c.org>
Cc: "musl@...ts.openwall.com" <musl@...ts.openwall.com>
Subject: Question about flexible array

hi,

In arch/loongarch64/bits/signal.h, I got some compiling errors about flexible array:

In file included from /usr/include/signal.h:48,
                 from /usr/include/ucontext.h:9,
                 from /home/alpine/aports/community/onetbb/src/oneTBB-2021.12.0/python/rml/../../src/tbb/co_context.h:52,
                 from /home/alpine/aports/community/onetbb/src/oneTBB-2021.12.0/python/rml/../../src/tbb/scheduler_common.h:27,
                 from /home/alpine/aports/community/onetbb/src/oneTBB-2021.12.0/python/rml/ipc_server.cpp:23:
/usr/include/bits/signal.h:35:23: error: flexible array member 'mcontext_t::__extcontext' not at end of 'struct tbb::detail::r1::coroutine_type'
   35 |         unsigned long __extcontext[] __attribute__((__aligned__(16)));
      |                       ^~~~~~~~~~~~
compilation terminated due to -Wfatal-errors.
ninja: subcommand failed
>>> ERROR: onetbb: build failed

The reason is a difference between gcc and g++:

Flexible array members are not officially part of C++.
Flexible array members were officially standardized in C99.

If *.cpp includes this header file, it may result in an error. I suggest to change it to size-zero array format.

Meanwhile, you can also consider the patch I attached.
Your opinions are welcome.

Thanks.

本邮件及其附件含有龙芯中科的商业秘密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制或散发）本邮件及其附件中的信息。如果您错收本邮件，请您立即电话或邮件通知发件人并删除本邮件。 
This email and its attachments contain confidential information from Loongson Technology , which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this email in error, please notify the sender by phone or email immediately and delete it. 
Download attachment "LoongArch-change-flexible-array-format.diff" of type "application/octet-stream" (717 bytes)

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.