"Richard Earnshaw (lists)" <richard.earns...@arm.com> writes:
> On 27/12/2024 21:47, Thiago Jung Bauermann wrote:
>> In 32-bit Arm assembly, the @ character is the start of a comment so
>> the section type needs to use the % character instead.
>>
>> configure.ac attempts to account for this difference by doing a second
>> try when checking the assembler for section merging support.
>> Unfortunately there is a bug: because the gcc_GAS_CHECK_FEATURE macro
>> has a call to AC_CACHE_CHECK, it will actually skip the second try
>> because the gcc_cv_as_shf_merge variable has already been set:
>>
>> checking assembler for section merging support... no
>> checking assembler for section merging support... (cached) no
>>
>> Fix by using a separate variable for the second try, as is done in the
>> check for COMDAT group support.
>>
>> This problem was noticed because the recent binutils commit
>> d5cbf916be4a ("gas/ELF: also reject merge entity size being zero") caused
>> gas to be stricter about mergeable sections without an entity size:
>>
>> configure:27013: checking assembler for section merging support
>> configure:27022: /path/to/as --fatal-warnings -o conftest.o conftest.s >&5
>> conftest.s: Assembler messages:
>> conftest.s:1: Warning: invalid merge / string entity size
>> conftest.s: Error: 1 warning, treating warnings as errors
>> configure:27025: $? = 1
>> configure: failed program was
>> .section .rodata.str, "aMS", @progbits, 1
>> configure:27036: result: no
>>
>> In previous versions of gas the conftest.s program above was accepted
>> and configure detected support for section merging.
>>
>> See also:
>> https://linaro.atlassian.net/browse/GNU-1427
>> https://sourceware.org/bugzilla/show_bug.cgi?id=32491
>>
>> Tested on armv8l-linux-gnueabihf.
>>
>> gcc/ChangeLog:
>> * configure.ac: Fix check for HAVE_GAS_SHF_MERGE on Arm targets.
>> * configure: Regenerate.
>
> OK.
>
> R.
Thank you! Pushed as commit 36eee5a74eb6.
Is it ok if I also push it to the supported branches releases/gcc-12,
releases/gcc-13 and releases/gcc-14?
--
Thiago
