clang: error: clang frontend command failed due to signal

[rajpreet123]

I encountered a segmentation error while generating the AST.
The error occurs in line 95 of eventloop.h.
I was unable to reduce the code, so I am attaching libpurple.tar along with the incomplete JSON file.
I hope these files will help in resolving the issue.

Stack dump:
0.      Program arguments: clang -Xclang -ast-dump=json -fsyntax-only purple.h
1.      <eof> parser at end of file
Exception Code: 0xC0000005

 #0 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x3bb1063 C:\Program Files\LLVM\bin\clang.exe 0x3bb096c
 #1 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x3bb06f2 C:\Program Files\LLVM\bin\clang.exe 0x3bb3ed0
 #2 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x32188a2 C:\Program Files\LLVM\bin\clang.exe 0x31ff7de
 #3 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x320f2a4 C:\Program Files\LLVM\bin\clang.exe 0x31ff597
 #4 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x320020a C:\Program Files\LLVM\bin\clang.exe 0x31ff85c
 #5 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x320f2a4 C:\Program Files\LLVM\bin\clang.exe 0x31ff597
 #6 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x320020a C:\Program Files\LLVM\bin\clang.exe 0x31ff85c
 #7 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x31ff32b C:\Program Files\LLVM\bin\clang.exe 0x31f4f4f
 #8 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x3619d05 C:\Program Files\LLVM\bin\clang.exe 0x2340013
 #9 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x30497 C:\Program Files\LLVM\bin\clang.exe 0x2ff37
#10 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x2c82d C:\Program Files\LLVM\bin\clang.exe 0x2b306
#11 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x29afe C:\Program Files\LLVM\bin\clang.exe 0x1271fed
#12 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x724f15 C:\Program Files\LLVM\bin\clang.exe 0x724d18
#13 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x137258 C:\Program Files\LLVM\bin\clang.exe 0x136c0c
#14 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x136727 C:\Program Files\LLVM\bin\clang.exe 0x12fb20
#15 0x00007ff73de21063 C:\Program Files\LLVM\bin\clang.exe 0x12edb1 C:\Program Files\LLVM\bin\clang.exe 0x23c68b0
#16 0x00007ff73de21063 (C:\Program Files\LLVM\bin\clang.exe+0x3bb1063)
#17 0x00007ff73de2096c (C:\Program Files\LLVM\bin\clang.exe+0x3bb096c)
0x00007FF73DE21063, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x3BB1063 byte(s)
0x00007FF73DE2096C, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x3BB096C byte(s)
0x00007FF73DE206F2, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x3BB06F2 byte(s)
0x00007FF73DE23ED0, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x3BB3ED0 byte(s)
0x00007FF73D4888A2, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x32188A2 byte(s)
0x00007FF73D46F7DE, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x31FF7DE byte(s)
0x00007FF73D47F2A4, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x320F2A4 byte(s)
0x00007FF73D46F597, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x31FF597 byte(s)
0x00007FF73D47020A, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x320020A byte(s)
0x00007FF73D46F85C, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x31FF85C byte(s)
0x00007FF73D47F2A4, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x320F2A4 byte(s)
0x00007FF73D46F597, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x31FF597 byte(s)
0x00007FF73D47020A, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x320020A byte(s)
0x00007FF73D46F85C, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x31FF85C byte(s)
0x00007FF73D46F32B, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x31FF32B byte(s)
0x00007FF73D464F4F, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x31F4F4F byte(s)
0x00007FF73D889D05, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x3619D05 byte(s)
0x00007FF73C5B0013, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x2340013 byte(s)
0x00007FF73A2A0497, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x30497 byte(s)
0x00007FF73A29FF37, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x2FF37 byte(s)
0x00007FF73A29C82D, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x2C82D byte(s)
0x00007FF73A29B306, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x2B306 byte(s)
0x00007FF73A299AFE, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x29AFE byte(s)
0x00007FF73B4E1FED, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x1271FED byte(s)
0x00007FF73A994F15, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x724F15 byte(s)
0x00007FF73A994D18, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x724D18 byte(s)
0x00007FF73A3A7258, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x137258 byte(s)
0x00007FF73A3A6C0C, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x136C0C byte(s)
0x00007FF73A3A6727, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x136727 byte(s)
0x00007FF73A39FB20, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x12FB20 byte(s)
0x00007FF73A39EDB1, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x12EDB1 byte(s)
0x00007FF73C6368B0, C:\Program Files\LLVM\bin\clang.exe(0x00007FF73A270000) + 0x23C68B0 byte(s)
0x00007FFDA979257D, C:\Windows\System32\KERNEL32.DLL(0x00007FFDA9780000) + 0x1257D byte(s), BaseThreadInitThunk() + 0x1D byte(s)
0x00007FFDAB4AAF08, C:\Windows\SYSTEM32\ntdll.dll(0x00007FFDAB450000) + 0x5AF08 byte(s), RtlUserThreadStart() + 0x28 byte(s)
clang: error: clang frontend command failed due to signal (use -v to see invocation)
clang version 17.0.5
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: C:\Program Files\LLVM\bin
clang: note: diagnostic msg: Error generating preprocessed source(s).

libpurple.zip
purple.h_output.zip

[Endilll]

We'd appreciate if you preprocess your input (purple.h) and check that it reproduces using latest release (19) or trunk (20).
We need a self-contained reproducer.

[rajpreet123]

The error occurs on line 95 of eventloop.h. However, the crash does not occur when a standalone piece of code from this file is extracted and compiled separately. Seems that the issue is influenced by the compilation order of various files. Hence, it is challenging for me to isolate minimal code that reliably reproduces the crash.

The crash is also present in the latest release, version 19.1.4

Stack dump:
0.      Program arguments: clang -Xclang -ast-dump -fsyntax-only C:\\libpurple\\purple.h
1.      <eof> parser at end of file
Exception Code: 0xC0000005
 #0 0x00007ff7d84375c3 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x37275c3)
 #1 0x00007ff7d8436d7d (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x3726d7d)
 #2 0x00007ff7d8436ad2 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x3726ad2)
 #3 0x00007ff7d843ac07 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x372ac07)
 #4 0x00007ff7d78c0d62 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x2bb0d62)
 #5 0x00007ff7d7901c86 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x2bf1c86)
 #6 0x00007ff7d7908206 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x2bf8206)
 #7 0x00007ff7d7901aba (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x2bf1aba)
 #8 0x00007ff7d79027d5 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x2bf27d5)
 #9 0x00007ff7d7901d00 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x2bf1d00)
#10 0x00007ff7d7908206 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x2bf8206)
#11 0x00007ff7d7901aba (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x2bf1aba)
#12 0x00007ff7d79027d5 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x2bf27d5)
#13 0x00007ff7d7901d00 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x2bf1d00)
#14 0x00007ff7d790192d (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x2bf192d)
#15 0x00007ff7d79013c9 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x2bf13c9)
#16 0x00007ff7d7d912a5 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x30812a5)
#17 0x00007ff7d6873968 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x1b63968)
#18 0x00007ff7d52d2f31 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x5c2f31)
#19 0x00007ff7d52d2ac2 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x5c2ac2)
#20 0x00007ff7d52cf836 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x5bf836)
#21 0x00007ff7d52cc7f5 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x5bc7f5)
#22 0x00007ff7d52cb18e (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x5bb18e)
#23 0x00007ff7d59e4aed (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0xcd4aed)
#24 0x00007ff7d5454de5 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x744de5)
#25 0x00007ff7d5454bd8 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x744bd8)
#26 0x00007ff7d515ba48 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x44ba48)
#27 0x00007ff7d515adce (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x44adce)
#28 0x00007ff7d515a947 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x44a947)
#29 0x00007ff7d51520d6 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x4420d6)
#30 0x00007ff7d514f853 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x43f853)
#31 0x00007ff7d6913bd8 (C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin\clang.exe+0x1c03bd8)
#32 0x00007ffda979257d (C:\Windows\System32\KERNEL32.DLL+0x1257d)
#33 0x00007ffdab4aaf08 (C:\Windows\SYSTEM32\ntdll.dll+0x5af08)
clang: error: clang frontend command failed due to signal (use -v to see invocation)
clang version 19.1.4
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: C:\clang+llvm-19.1.4-x86_64-pc-windows-msvc\bin
clang: note: diagnostic msg: Error generating preprocessed source(s).

[rajpreet123]

Hi @AaronBallman, @Endilll
Refer attached docker file and code file to replicate the issue at your end.
DockerFile: https://gist.github.com/rajpreet123/caca353aeb593b3c599f323783dcde8c

Thanks,

libpurple.zip

[Endilll]

However, the crash does not occur when a standalone piece of code from this file is extracted and compiled separately.

Does it occur if you first create a preprocessed source using -E flag, and then compile it?

[rajpreet123]

Hi @Endilll,

No, It doesn't crash if we first create preprocessed source.

[rajpreet123]

Hi @Endilll,
Is there any estimated timeline for a fix ?
Thanks,

[AaronBallman]

Hi @Endilll, Is there any estimated timeline for a fix ? Thanks,

Sorry, but there isn't. I suspect folks don't have time to try to further reduce the issue to narrow down the problem to something more tractable, which is basically what prevents anyone from trying to fix it. Anything you can do to try to help narrow the issue down would be really appreciated (otherwise, I suspect this bug will languish). If it depends on compilation order, even getting it down to "compile x.cpp y.cpp and it crashes, but compile y.cpp x.cpp and it doesn't" would help. Probably not the answer you're hoping for, but we don't have any dedicated QA resources to help with this sort of thing.

[Endilll]

I can confirm that a reproducer that requires me to deal with Docker gets a lower priority than a reproducer from Compiler Explorer. Given the number of open issues we have, in practical terms it means that issue can remain open for years until someone really interested in this comes by and puts the effort, or it accidentally gets fixed while fixing something else, but no one notices, and the issue remains open.