From: Nick Alcock <nick.alcock@oracle.com>
To: Alan Modra <amodra@gmail.com>
Cc: Nick Alcock <nick.alcock@oracle.com>,
binutils@sourceware.org,
Indu Bhagat <gitlab@linux-git.oraclecorp.com>
Subject: Re: [PATCH 4/4] libctf: get the offsets of fields of unnamed structs/unions right
Date: Mon, 27 Mar 2023 11:27:40 +0100 [thread overview]
Message-ID: <87y1nilc9v.fsf@esperi.org.uk> (raw)
In-Reply-To: <ZB6Ptl1/1lJ6tX2E@squeak.grove.modra.org> (Alan Modra's message of "Sat, 25 Mar 2023 16:37:50 +1030")
On 25 Mar 2023, Alan Modra verbalised:
> On Fri, Mar 24, 2023 at 01:36:25PM +0000, Nick Alcock via Binutils wrote:
>> * testsuite/libctf-lookup/unnamed-field-info*: New test.
>
> arm-linux-gnueabi +FAIL: /home/alan/src/binutils-gdb/libctf/testsuite/libctf-lookup/unnamed-field-info.c
> hppa-linux-gnu +FAIL: /home/alan/src/binutils-gdb/libctf/testsuite/libctf-lookup/unnamed-field-info.c
> m68k-linux-gnu +FAIL: /home/alan/src/binutils-gdb/libctf/testsuite/libctf-lookup/unnamed-field-info.c
> microblaze-linux-gnu +FAIL: /home/alan/src/binutils-gdb/libctf/testsuite/libctf-lookup/unnamed-field-info.c
> mips-linux-gnu +FAIL: /home/alan/src/binutils-gdb/libctf/testsuite/libctf-lookup/unnamed-field-info.c
> powerpc-linux-gnu +FAIL: /home/alan/src/binutils-gdb/libctf/testsuite/libctf-lookup/unnamed-field-info.c
> s390-linux-gnu +FAIL: /home/alan/src/binutils-gdb/libctf/testsuite/libctf-lookup/unnamed-field-info.c
> sh4-linux-gnu +FAIL: /home/alan/src/binutils-gdb/libctf/testsuite/libctf-lookup/unnamed-field-info.c
Weird. I tested on two of those! (arm and powerpc).
Are they all 32-bit platforms? It looks like it.
> The fails look like:
> field b inconsistency: offsetof() says 64 bits, CTF says 32
> field one inconsistency: offsetof() says 128 bits, CTF says 64
> field two inconsistency: offsetof() says 192 bits, CTF says 96
> field three inconsistency: offsetof() says 256 bits, CTF says 128
> field four inconsistency: offsetof() says 320 bits, CTF says 160
> field x inconsistency: offsetof() says 384 bits, CTF says 192
> field y inconsistency: offsetof() says 448 bits, CTF says 256
> field z inconsistency: offsetof() says 384 bits, CTF says 192
> field aleph inconsistency: offsetof() says 448 bits, CTF says 224
All failing platforms are 32-bit, and they're all out by a factor of
two. Just a coincidence, perhaps. (Definitely no more than a vague
hunch.)
I'll take a look. Maybe I can just make the test less picky -- all we're
actually interested in for this bug is "CTF says 0". But this is worthy
of investigation regardless. It's just as likely to be a compiler bug
as a bug in libctf, I'd guess.
--
NULL && (void)
next prev parent reply other threads:[~2023-03-27 10:27 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-24 13:36 [PATCH 1/4] libctf: fix assertion failure with no system qsort_r Nick Alcock
2023-03-24 13:36 ` [PATCH 2/4] libctf: work around an uninitialized variable warning Nick Alcock
2023-03-24 13:36 ` [PATCH 3/4] libctf: fix a comment typo Nick Alcock
2023-03-24 13:36 ` [PATCH 4/4] libctf: get the offsets of fields of unnamed structs/unions right Nick Alcock
2023-03-25 6:07 ` Alan Modra
2023-03-27 10:27 ` Nick Alcock [this message]
2023-03-27 11:22 ` Alan Modra
2023-03-27 12:38 ` Nick Alcock
2023-04-06 11:46 ` Nick Alcock
2023-04-08 15:50 ` Nick Alcock
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