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Date: Thu, 23 Feb 2023 21:24:09 +0000
From: Joseph Myers <joseph@codesourcery.com>
To: Qing Zhao <qing.zhao@oracle.com>
CC: Richard Biener <rguenther@suse.de>, Siddhesh Poyarekar
	<siddhesh@gotplt.org>, Kees Cook <keescook@chromium.org>, Gcc Patches
	<gcc-patches@gcc.gnu.org>
Subject: Re: Fwd: [v3][PATCH 2/2] Update documentation to clarify a GCC
 extension (PR77650)
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Message-ID: <68c735b-90cc-14ef-be83-db1b754ad0f4@codesourcery.com>
References: <20230211005013.789161-3-qing.zhao@oracle.com> <89D4C326-54FD-4403-8E54-6CE5B21AA411@oracle.com>
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On Thu, 23 Feb 2023, Qing Zhao via Gcc-patches wrote:

> +@item
> +The structure with a C99 flexible array member is the field of
> +another union, for example:
> +
> +@smallexample
> +struct flex1  @{ int length1; char data1[]; @}
> +struct flex2  @{ int length2; char data2[]; @}
> +
> +union out_flex @{ struct flex1 flex_data1; struct flex2 flex_data2; @}

I don't think this is an extension; structures with flexible array members 
are OK in unions in standard C.

-- 
Joseph S. Myers
joseph@codesourcery.com