Re: [TRACKING] gcc 12 build failures

[oreo639 <oreo639@users.noreply.github.com>]

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New comment by oreo639 on void-packages repository

https://github.com/void-linux/void-packages/issues/39809#issuecomment-1336554579

Comment:
The ldc build failure seems to be a segfault in ldc2.
Even after updating it still crashes.
The crash location I got was:
https://github.com/ldc-developers/ldc/blob/master/gen/target.cpp#L180
```
Program received signal SIGSEGV, Segmentation fault.
Target::_init (this=0xbc7d78 <target>, params=...) at /builddir/ldc-1.30.0/gen/target.cpp:180
180	    RealProperties.min_10_exp = -4931;
(gdb) 
(gdb) bt
#0  Target::_init (this=0xbc7d78 <target>, params=...)
    at /builddir/ldc-1.30.0/gen/target.cpp:180
#1  0x000000000081acfd in mars_mainBody(Param&, Array<char const*>&, Array<char const*>&) (params=..., files=..., libmodules=...)
    at /builddir/ldc-1.30.0/dmd/mars.d:336
#2  0x00000000009d1f0e in cppmain ()
    at /builddir/ldc-1.30.0/driver/main.cpp:1148
#3  0x000000000091a04d in _Dmain (_param_0=...)
    at /builddir/ldc-1.30.0/driver/main.d:27
```
Here is a snippet of the disas:
```
...
   0x000000000095e6ca <+1402>:	xor    %esi,%esi
   0x000000000095e6cc <+1404>:	mov    $0xaaf859,%edi
   0x000000000095e6d1 <+1409>:	fstpt  0x180(%rbx)
   0x000000000095e6d7 <+1415>:	call   0x913210 <_ZN7CTFloat5parseEPKcPb>
   0x000000000095e6dc <+1420>:	xor    %esi,%esi
   0x000000000095e6de <+1422>:	mov    $0xaaf864,%edi
   0x000000000095e6e3 <+1427>:	fstpt  0x190(%rbx)
   0x000000000095e6e9 <+1433>:	call   0x913210 <_ZN7CTFloat5parseEPKcPb>
   0x000000000095e6ee <+1438>:	movdqa 0x15138a(%rip),%xmm0        # 0xaafa80
   0x000000000095e6f6 <+1446>:	fstpt  0x1c0(%rbx)
=> 0x000000000095e6fc <+1452>:	movaps %xmm0,0x1d0(%rbx)
```

I assume this has to do with LLVM and libstdc++, alpine uses LLVM 14 although even after updating to that the crash still occurs (albeit in a slightly different place, but still in `Target::_init()`). I can also confirm that updating musl and using the gcc git  snapshot alpine uses doesn't fix the crash either. The build failure also occurs with clang/clang++ and libstdc++ although when I try to build it with libc++ I get a bunch of undefined references to LLVM.

Also, sidenote but libexecinfo is broken on musl:
https://github.com/alpinelinux/aports/commit/50795a14dee639ce2dcc836e2b2baca9bad4a1b1
Although removing it/stubbing it out didn't fix the issue it did stop libexecinfo from messing up the gdb backtrace.

EDIT 1: compiling ldc without using dmd works fine.