<div class="__aliyun_email_body_block"><div style="clear:both;"><span style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">Hi,</span></div><div style="clear:both;"><span style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;"><br ></span></div><div style="clear:both;"><span style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">Sorry for disturbing. I find that I made a mistake after I revert </span><span style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;"></span><span style="caret-color:#000000;color:#000000;font-family:monospace;font-size:medium;white-space:pre-wrap;">e08f205f / D70350. I only recompile the clang instead of the lld. However, I met this problem within ThinLTO : (. Finally, the workaround to revert e08f205f/D70350 works for my case. Thanks a lot!</span></div><div style="clear:both;"><span style="caret-color:#000000;color:#000000;font-family:monospace;font-size:medium;white-space:pre-wrap;"><br ></span></div><div style="clear:both;"><span style="caret-color:#000000;color:#000000;font-family:monospace;font-size:medium;white-space:pre-wrap;">Thanks,</span></div><div style="clear:both;"><span style="caret-color:#000000;color:#000000;font-family:monospace;font-size:medium;white-space:pre-wrap;">Chuanqi</span></div><blockquote style="margin-right:0;margin-top:0;margin-bottom:0;"><div style="clear:both;"><span style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">------------------------------------------------------------------</span></div><div style="clear:both;"><span style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">From:chuanqi.xcq <yedeng.yd@linux.alibaba.com></span></div><div style="clear:both;"><span style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">Send Time:2021年5月28日(星期五) 11:23</span></div><div style="clear:both;"><span style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">To:Jeremy Morse <jeremy.morse.llvm@gmail.com>; David Blaikie <dblaikie@gmail.com></span></div><div style="clear:both;"><span style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">Cc:llvm-dev@lists.llvm.org <llvm-dev@lists.llvm.org>; aprantl <aprantl@apple.com></span></div><div style="clear:both;"><span style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">Subject:Re: How to handle DWARF Missing due to function elimination?</span></div><div style="clear:both;"><span style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;"><br /></span></div><div style="clear:both;"> Hi,</div><div style="clear:both;"><br ></div><div style="clear:both;">Although it looks like the same problem within the link (I met this within ThinLTO and bug 48790 met in LTO), it can't help after I revert <span style="font-family:monospace;font-size:medium;">e08f205f. (You mentioned <span class=" __aliyun_node_has_color __aliyun_node_has_bgcolor" style="caret-color:#000000;color:#000000;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;font-style:normal;font-variant-caps:normal;font-weight:normal;text-align:start;text-indent:.0px;text-transform:none;background-color:#ffffff;text-decoration:none;float:none;display:inline;">93592b726c7 but I believe it shouldn't be true</span>).</span></div><div style="clear:both;">I met this in a complex production code. I would try to give an minimal repro if possible.</div><div style="clear:both;"><br ></div><div style="clear:both;">Thanks,</div><div style="clear:both;">Chuanqi</div><div style="clear:both;"><span class=" __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;"><br ></span></div><div style="clear:both;"><span class=" __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">------------------------------------------------------------------</span></div><div style="clear:both;"><span class=" __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">From:David Blaikie <dblaikie@gmail.com></span></div><div style="clear:both;"><span class=" __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">Send Time:2021年5月28日(星期五) 02:01</span></div><div style="clear:both;"><span class=" __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">To:Jeremy Morse <jeremy.morse.llvm@gmail.com></span></div><div style="clear:both;"><span class=" __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">Cc:chuanqi.xcq <yedeng.yd@linux.alibaba.com>; llvm-dev@lists.llvm.org <llvm-dev@lists.llvm.org>; aprantl <aprantl@apple.com></span></div><div style="clear:both;"><span class=" __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">Subject:Re: How to handle DWARF Missing due to function elimination?</span></div><div style="clear:both;"><span class=" __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;"><br ></span></div><div >Yeah - would be good to know what the examples are - generally that is not expected (even with linker GC or other cases of symbol removal) & so is most likely something to be fixed in LLVM - but yeah, if the debugger is actually /crashing/ that's also not good, and it shouldn't do that (but lesser problem, because it also shouldn't encounter debug info like this, generally).</div><br ><div class="gmail_quote"><div class="gmail_attr">On Thu, May 27, 2021 at 4:47 AM Jeremy Morse <<a href="mailto:jeremy.morse.llvm@gmail.com" target="_blank">jeremy.morse.llvm@gmail.com</a>> wrote:<br ></div>Hi Chuanqi,<br ><br >
On Thu, May 27, 2021 at 12:11 PM chuanqi.xcq<br >
<<a href="mailto:yedeng.yd@linux.alibaba.com" target="_blank">yedeng.yd@linux.alibaba.com</a>> wrote:<br >
> The gdb would blame when it finds 0x0123456 doesn't refer to any functions in dwarf format.<br ><br >
This is really interesting -- if you run "llvm-dwarfdump -verify" on<br >
the output file, does it too complain about an invalid DIE reference?<br ><br >
There's a known issue with very complicated LTO builds that causes<br >
something similar:<br ><br >
<a href="https://bugs.llvm.org/show_bug.cgi?id=48790" target="_blank">https://bugs.llvm.org/show_bug.cgi?id=48790</a><br ><br >
Reverting 93592b726c7 locally will tell you whether it's that or not.<br ><br >
--<br >
Thanks,<br >
Jeremy<br ></div><div ><br ></div></blockquote></div>