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From: "Ludovic Courtès via Libc-alpha" <libc-alpha@sourceware.org>
To: Vineet Gupta <vineetg@rivosinc.com>
Cc: libc-alpha@sourceware.org,  Carlos O'Donell <carlos@redhat.com>,
	Fangrui Song <maskray@google.com>,
	 nelson Chu <nelson@rivosinc.com>,
	palmer@rivosinc.com,  gnu-toolchain@rivosinc.com
Subject: Re: [PATCH] Revert "Correctly determine libc.so 'OUTPUT_FORMAT' when cross-compiling."
Date: Sat, 26 Nov 2022 15:57:42 +0100	[thread overview]
Message-ID: <87lenx9315.fsf@gnu.org> (raw)
In-Reply-To: <20221123025932.473655-1-vineetg@rivosinc.com> (Vineet Gupta's message of "Tue, 22 Nov 2022 18:59:32 -0800")

Hi,

Vineet Gupta <vineetg@rivosinc.com> skribis:

> This reverts commit 361d6454c034a920f2c96517c277990d390b9652.
>
> This trips up riscv gnu toolchain builds [1]
>
> riscv ld segfaults when linking libgcc because libc.so linker script
> contains `OUTPUT_FORMAT(elf32-little)` vs. `OUTPUT_FORMAT(elf32-littleriscv)`.
>
> This patch causes builds to lookup riscv32* prefixed objdump and failing
> to find it falls back to host objdump which is the root of the issue.
> The host objdump in turn generates `OUTPUT_FORMAT(elf32-little)`
>
> riscv glibc multilib builds lack riscv32 prefix binaries. They have a
> single set of "riscv64" prefixed binaries supporting both 32 and 64-bit
> abis: ilp32/ilp32d/lp64/lp64d using -march/-mabi.
>
> FWIW I'm not sure how this patch fixed a real problem to begin with.

The rationale was described in the context of cross-compilation to
aarch64-linux-gnu:

  https://sourceware.org/pipermail/libc-alpha/2021-July/128333.html

We observed a similar issue with objcopy when cross-compiling to
powerpc64le-linux-gnu:

  https://issues.guix.gnu.org/49417

Maybe we should see, in your case, why “riscv32-linux-gnu-objdump -f”
reports “elf32-little” instead of “elf32-littleriscv”?

HTH,
Ludo’.

  reply	other threads:[~2022-11-26 14:58 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-23  2:59 [PATCH] Revert "Correctly determine libc.so 'OUTPUT_FORMAT' when cross-compiling." Vineet Gupta
2022-11-26 14:57 ` Ludovic Courtès via Libc-alpha [this message]
2022-11-28  2:24   ` Vineet Gupta
2022-11-28 15:37     ` Ludovic Courtès via Libc-alpha
2022-11-28 19:04       ` Vineet Gupta
2022-11-28 23:25 ` Palmer Dabbelt
2022-11-30 12:39   ` Adhemerval Zanella Netto via Libc-alpha
2022-12-01  0:45     ` Vineet Gupta

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