Re: [PATCH] package.py: warn if target is not a valid ELF file in dwarfsrcfiles

["mark.yang" <mark.yang@lge.com>]

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My error report is as follows.
https://errors.yoctoproject.org/Errors/Details/892988/

I am using only the openembedded-core layer, with nodistro.
local.conf

> 
> PREFERRED_TOOLCHAIN_TARGET = "clang"
> DISTRO_FEATURES:append = " ld-is-lld"
> require conf/distro/include/lto.inc
> DISTRO_FEATURES:append = " lto"
> # The settings below were taken from meta-clang.
> LTO:toolchain-clang:class-target =
> "${@bb.utils.contains('DISTRO_FEATURES', 'thin-lto', '-flto=thin', '-flto
> -fuse-ld=lld', d)}"
> LTO:toolchain-clang:class-nativesdk =
> "${@bb.utils.contains('DISTRO_FEATURES', 'thin-lto', '-flto=thin', '-flto
> -fuse-ld=lld', d)}"
> 

dwarfsrcfiles checks .a files during the package process.
Whether using LTO or not, DWARF information is extracted by iterating through .o files inside .a files.
However, they must be ELF objects.

To summarize, it is as follows.
The problem is that when using clang + LTO, the .o files are not ELF but LLVM IR bitcode.

On Sat, Dec 27, 2025 at 03:31 AM, Alexander Kanavin wrote:

> 
> Can you please provide a way to reproduce and observe the issue? I'm
> somewhat confused as to what the original issue is: is dwarfsrcfiles
> called on an .a file? That is not an ELF file regardless of whether
> clang-with-lto is enabled, so why does it work in one case but not in
> the other?
> 
> Alex
> On Fri, 26 Dec 2025 at 08:36, mark.yang via lists.openembedded.org
> <mark.yang=lge.com@lists.openembedded.org> wrote:
> 
>> 
>> From: "mark.yang" <mark.yang@lge.com>
>> 
>> When using the Clang toolchain with LTO, intermediate .o files are
>> generated as
>> LLVM bitcode files instead of ELF files. While .so libraries are
>> ultimately
>> ELF, .a files are not. In this case, dwarfsrcfiles always fails.
>> 
>> Adding the -ffat-lto-objects option allows the Clang toolchain to produce
>> .o
>> files that are recognized as ELF, but this is not always a suitable
>> solution
>> as it causes issues when used in conjunction with -fsanitize=cfi.
>> 
>> Therefore, we need to handle cases where dwarfsrcfiles encounters a file
>> that
>> is not a valid ELF. Change the behavior from a fatal error to a warning to
>> 
>> notify the user.
>> 
>> Signed-off-by: mark.yang <mark.yang@lge.com>
>> ---
>> meta/lib/oe/package.py | 8 ++++++--
>> 1 file changed, 6 insertions(+), 2 deletions(-)
>> 
>> diff --git a/meta/lib/oe/package.py b/meta/lib/oe/package.py
>> index baaa0cba02..56b9bcd546 100644
>> --- a/meta/lib/oe/package.py
>> +++ b/meta/lib/oe/package.py
>> @@ -782,8 +782,12 @@ def source_info(file, d, fatal=True):
>> if retval != 0 and retval != 255:
>> msg = "dwarfsrcfiles failed with exit code %s (cmd was %s)%s" % (retval,
>> cmd, ":\n%s" % output if output else "")
>> if fatal:
>> - bb.fatal(msg)
>> - bb.note(msg)
>> + if "not a valid ELF file" in output:
>> + bb.warn(msg)
>> + else:
>> + bb.fatal(msg)
>> + else:
>> + bb.note(msg)
>> 
>> debugsources = parse_debugsources_from_dwarfsrcfiles_output(output)
>> 
>> 
>> 
>> 
> 
>

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