<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Issue</th>
<td>
<a href=https://github.com/llvm/llvm-project/issues/62998>62998</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>
clang: error: unable to execute command: Segmentation fault
</td>
</tr>
<tr>
<th>Labels</th>
<td>
new issue
</td>
</tr>
<tr>
<th>Assignees</th>
<td>
</td>
</tr>
<tr>
<th>Reporter</th>
<td>
zxcuiop
</td>
</tr>
</table>
<pre>
```
#include <stdlib.h>
__attribute__ ((noinline))
void foo (float **a, float *c, int m, int l)
{
int n = 0;
float ** b = 0;
int i,j,k;
float s;
for (i=0; i<l; )
for (j=0; 0<n; j++)
for (k=0; k<m; )
c[i] += a[i][k] * b[k][0];
}
int main()
{
const int N = 32;
float **ar1, **ar2;
float *res;
int i, j;
ar1 = (float **)malloc (N * sizeof (float*));
ar2 = (float **)malloc (N * sizeof (float*));
res = (float *)malloc( N * sizeof (float));
for (i=0; i<N; i++)
{
ar1[i] = (float*)(0);
ar2[i] = (float*)malloc (N * sizeof (float));
}
for (i=0; i<N; i++)
{
for (j=0; j<N; j++)
{
ar1[i][j] = 2.0f;
ar2[i][j] = 1.5f;
}
res[i] = 0.0f;
}
foo (ar1, res, N, N);
for (i=0; i<N; i++)
if (res[i] != 3072.0f)
abort();
for (i=0; i<=N; i++)
res[i] = 0.0f;
foo (ar1, res, 0, N);
for (i=0; i<N; i++)
{
res[i] != 0.0f;
abort();
}
return 0;
}
```
When compile the above code with clang, clang outputs:
```
$ clang -O2 small.c
small.c:47:12: warning: inequality comparison result unused [-Wunused-comparison]
res[i] != 0.0f;
~~~~~~~^~~~~~~
small.c:47:12: note: use '|=' to turn this inequality comparison into an or-assignment
res[i] != 0.0f;
^~
|=
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0. Program arguments: /usr/lib/llvm-14/bin/clang -cc1 -triple x86_64-pc-linux-gnu -emit-obj --mrelax-relocations -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name small.c -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -mllvm -treat-scalable-fixed-error-as-warning -debugger-tuning=gdb -fcoverage-compilation-dir=/home/xfou/bugs/9 -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/bin/../lib/gcc/x86_64-linux-gnu/12/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/home/xfou/bugs/9 -ferror-limit 19 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/small-5d9742.o -x c small.c
1. <eof> parser at end of file
2. Optimizer
#0 0x00007ff0a2960d01 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0xe3fd01)
#1 0x00007ff0a295ea3e llvm::sys::RunSignalHandlers() (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0xe3da3e)
#2 0x00007ff0a2961236 (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0xe40236)
#3 0x00007ff0a160a520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
#4 0x00007ff0a29b1510 llvm::BasicBlock::isEntryBlock() const (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0xe90510)
#5 0x00007ff0a3c22acc llvm::isPotentiallyReachable(llvm::BasicBlock const*, llvm::BasicBlock const*, llvm::SmallPtrSetImpl<llvm::BasicBlock*> const*, llvm::DominatorTree const*, llvm::LoopInfo const*) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x2101acc)
#6 0x00007ff0a3c22ccc llvm::isPotentiallyReachable(llvm::Instruction const*, llvm::Instruction const*, llvm::SmallPtrSetImpl<llvm::BasicBlock*> const*, llvm::DominatorTree const*, llvm::LoopInfo const*) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x2101ccc)
#7 0x00007ff0a3bfbcd4 llvm::EarliestEscapeInfo::isNotCapturedBeforeOrAt(llvm::Value const*, llvm::Instruction const*) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x20dacd4)
#8 0x00007ff0a3bfe929 llvm::BasicAAResult::getModRefInfo(llvm::CallBase const*, llvm::MemoryLocation const&, llvm::AAQueryInfo&) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x20dd929)
#9 0x00007ff0a3be6348 llvm::AAResults::getModRefInfo(llvm::CallBase const*, llvm::MemoryLocation const&, llvm::AAQueryInfo&) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x20c5348)
#10 0x00007ff0a3be922b llvm::AAResults::getModRefInfo(llvm::Instruction const*, llvm::Optional<llvm::MemoryLocation> const&, llvm::AAQueryInfo&) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x20c822b)
#11 0x00007ff0a371a44c (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x1bf944c)
#12 0x00007ff0a37143b8 (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x1bf33b8)
#13 0x00007ff0a37105c5 llvm::DSEPass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x1bef5c5)
#14 0x00007ff0a54777dd (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x39567dd)
#15 0x00007ff0a2acfa3e llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function> >::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0xfaea3e)
#16 0x00007ff0a46ba27d (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x2b9927d)
#17 0x00007ff0a3c4113f llvm::CGSCCToFunctionPassAdaptor::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x212013f)
#18 0x00007ff0a46bbbad (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x2b9abad)
#19 0x00007ff0a3c3d628 llvm::PassManager<llvm::LazyCallGraph::SCC, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x211c628)
#20 0x00007ff0a39efccd (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x1ececcd)
#21 0x00007ff0a3c3f7f6 llvm::DevirtSCCRepeatedPass::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x211e7f6)
#22 0x00007ff0a39f03ad (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x1ecf3ad)
#23 0x00007ff0a3c3eba3 llvm::ModuleToPostOrderCGSCCPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x211dba3)
#24 0x00007ff0a39f01cd (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x1ecf1cd)
#25 0x00007ff0a2ace63e llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module> >::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0xfad63e)
#26 0x00007ff0a39eb273 llvm::ModuleInlinerWrapperPass::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x1eca273)
#27 0x00007ff0a546c1ad (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0x394b1ad)
#28 0x00007ff0a2ace63e llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module> >::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/lib/x86_64-linux-gnu/libLLVM-14.so.1+0xfad63e)
#29 0x00007ff0a9c55b9b (/lib/x86_64-linux-gnu/libclang-cpp.so.14+0x1862b9b)
#30 0x00007ff0a9c49a52 clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::StringRef, llvm::Module*, clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream> >) (/lib/x86_64-linux-gnu/libclang-cpp.so.14+0x1856a52)
#31 0x00007ff0a9f6f855 (/lib/x86_64-linux-gnu/libclang-cpp.so.14+0x1b7c855)
#32 0x00007ff0a8df7834 clang::ParseAST(clang::Sema&, bool, bool) (/lib/x86_64-linux-gnu/libclang-cpp.so.14+0xa04834)
#33 0x00007ff0a9f6bb71 clang::CodeGenAction::ExecuteAction() (/lib/x86_64-linux-gnu/libclang-cpp.so.14+0x1b78b71)
#34 0x00007ff0aa907b57 clang::FrontendAction::Execute() (/lib/x86_64-linux-gnu/libclang-cpp.so.14+0x2514b57)
#35 0x00007ff0aa85f3a6 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/lib/x86_64-linux-gnu/libclang-cpp.so.14+0x246c3a6)
#36 0x00007ff0aa98145b clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/lib/x86_64-linux-gnu/libclang-cpp.so.14+0x258e45b)
#37 0x000000000041328b cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/usr/lib/llvm-14/bin/clang+0x41328b)
#38 0x00000000004114bc (/usr/lib/llvm-14/bin/clang+0x4114bc)
#39 0x0000000000411307 main (/usr/lib/llvm-14/bin/clang+0x411307)
#40 0x00007ff0a15f1d90 __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:58:16
#41 0x00007ff0a15f1e40 call_init ./csu/../csu/libc-start.c:128:20
#42 0x00007ff0a15f1e40 __libc_start_main ./csu/../csu/libc-start.c:379:5
#43 0x000000000040e3b5 _start (/usr/lib/llvm-14/bin/clang+0x40e3b5)
clang: error: unable to execute command: Segmentation fault
clang: error: clang frontend command failed due to signal (use -v to see invocation)
Ubuntu clang version 14.0.0-1ubuntu1
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
clang: note: diagnostic msg:
********************
PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang: note: diagnostic msg: /tmp/small-da9778.c
clang: note: diagnostic msg: /tmp/small-da9778.sh
clang: note: diagnostic msg:
********************
```
My clang version is:
```
Ubuntu clang version 14.0.0-1ubuntu1
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzsW91u2z6yfxrlhpAhkfqwLnLh2HFbIG1zmuy_lwZFjRy2MqklqTTpxXn2A1KyLTp2m7i72F3sCQxboobDmd98cCRNqNZ8LQAug_QqSBcXtDMPUl3-fGIdl-1FKavnyyCLhk-0CKJZgAkXrOkqQAGZa1M1vJw8BOS6v7xaUWMULzsDqxUK8DTAUyG5aLiAABf24-geJa9QLaUlqRtJDQrwLMAzGuA5QrsR5k65MGhjj-xBs-MR5Ff9QU8hUEAWKArIbnTMGJUvLttJPMDzbwGef38xTY9HpLKC8oAsLAPEAzJv7MFOFoR2VN-2VFFA5sIefAvwlfuMiHfk37fk3wMy33hMg6hgQXrFg3SB7HyyQHQ4D9Kr7_3wDJXDSZBeRfZnK3eQL7Z87LdDkXLhjPISQiaFNg6TTw4pgk8gSVVsbbE9OUqmQB8BGn0bDVIVu3UOHCDAxYY2jWT2wienn-Y_QdY7wp7IfsbM8D-OmQJ9hNnAKcBTdILTAZtjTvOpP3jpDntDWHi3Nh8JsRV0Gvmr2D9rhJNTfgtAcchw5zdn64COhcO37dzDcAiiYjc1iAo0giBIr75t1cKTqN77dk-Hj9DFk9Sj26tjvXKEUzRm-EJxl5oGX3cz7e8n-_3pD-zMHfJjQXDsoi3KnX5-iqClVGaI118vGJDFyTV_rfYJTaM_1dTzhpcKvwR_r_dxtcf22Yeq6ZQYZfV9zjvYttz31wcQiMlNyxtA5gHsSo-AmKwA_eDmAbGGirXV3B0g2Zm2Mzogs-NMcTIQhp8x0jbSJqy_tD0hsyQPyCzGAZmhH1QJLtb2kAv4e0cbbp6dPFRxLYWFqWsM6kSnoUJBehV-7Y_DPZH19rfg-r_9X5BeDwen5RPSgP3tNKAA50Fu3SrAOTISOZzNA9cnROfCSEQFkirsq4oNCPN6Qa14Y89Hvb2dAG749uZ6dneNdFduuEEUld0aKWilMla6B2NaZya8DPByzc1DV06Y3AR42TSP25-wVfIbMBPgJde6s56-RFRUaFvRWJdgiuoHVFL23SjKwDpDq6BVkoG2VtGyU_2wnUm1loxTAxVSnUCaKd6aSS_ynaHsO6q6TbtzoGiCbpVcK7pBVK07i5EVGwV42WllxeTlVtg4CfCytPv1cnAyxmIUGsXbBtDTNFtlSdiysOGiewrXokMhbLgJZfkNheFGQUOfQgWNZNRwKTQKK65p2UBYKwAUsgaoNZYJS6ilgtDqDKLa0zkxHkHxmoNyw4yqKnykTQehoBvQKLQVRVjzph_YBgFy6w8rhxtZQYNazlDYchY28AgNwv0J12HLAYWbWtENhK3kwoAKyEJIASisN9Q8hKCUkCis6zZkUli7mIAspEBhLWSoZCcqLtahpUXhxlUyqmPG-mLDqbZy1p34wUUVGquZDsgCo9BQtQYTsrazcIZZgkLTCXADaxCgrMQbi4KFHagJNaNNDyF_gsrK5fw9HCIbhRWU3XoNyjJyob5YVyUKayYfQdE1hH326XGpuHIBtnyQGwjw8qmWnbV5t7aeWaBQQe9tlvK0j_TnQ-paxskkmkQodDgK2oRcP2sDm7fNtyEyBMWvOElGm9eR9o48mezWWzNmVe7deOfDVgC8JTz4OkL7cmF4sgfspQAD6RE-v5799iXcbhDWzhXeZu-6d6iG2xwX24G16JgNQc2lCMgimeBJ7NypkSqsOF0LqQ1nGoWPYB2e_4SwkbL1BnTTorCmVaU0X6NwsVq9m89X72d_Xa8WX2dflng1X35Yze4-BmQRo9DWA0uzaQO8dOEcplWRJ3giUfiEmL_PxZMhVZM5yDog16ilSoNC1CCbS2SNbHLoifFA_Lk1fMN_gtomf0wiFD1FURTldR1RXGRRFcXIpW4yC8hMP-v-4FZxYVxive-z83RPpOiPldQ2UDcBzob7xQAX_W3o4HZHnKjh5c3NXx_DOJloOYkDfBU9AamrKN4XNAEmsS9iCpTAMRG_dOKOrwVt3lNRNaB0X8mcJ0VFCXhS4AOgYkyys1gnESaZx5qMWcdZRFMcvYI1s0wzxzTBKY48nokvbhmncTQC7Ypqzq4ayb7351xfC6Oe-5Eetv6-9BwNiyiNfWnSsTSEYUwZG0nD9a00IAynTfP8BSh7sLne87G9wL1g7h5rflSjEwR3NnxujboD82HTNgGZH4UDz2wwHWexkBsuqJHq3m7kx2lupGw_iFqOLp_lgjiOYmpT9QjG7BBG9lYYPww7NJfihPy_p_gPBJIdAJl7QJZ1yapktPQ1VQ0Hba41oy1YIbYAf5JmTlvTKaiuXPH2Wc2Mh_Bftkh7E7bnaRVVlFWJp9X0QCsocHEYIbPZF3ev0w-twXyU1ReonY5jNea0aa6oPqXJR9hI9XwzFJpboswnms3-pwP13PPOzle0KkYPMK2iha8oZCSZeuv2Our_ICVZSpLR40FM4uhAyQLj8hwlfx_QtiyQgvqR7Cs_CuV_kv5TjEtPf2_bJ3lMk4Sdwzsu6yJJmMcbH_BOSDk9kzchpW83csA7Slk6Tn1317dUD1ZTnfBsteyEM9RLlAVtnjXXH6mga3ubNj8yiVyfb4G4hDplqaeJV0OkSZ7nVXUOb1KkWV5VHm-vIsCU1X5RZyH6pa7noIMsQv9muNcUxpWmhcbb5ZOspDg_C3ZcFgXOfdj9jY8lcUzqkbrzd3fz-b3camatMKtoa6Q6jtsN_flsk-g7RduHoTqYz9-E4ikWXing0eBsi_gvabyrTrG_tRU1MOx_5-eqGEcxqT1YpwcmK0t6rsloSX2T-ZsdI1WGp6-IlNfg-k-xyx8a5VSI_ne6Wswy7G0v2C8LCqgZO8vVYmDAmOdqOD5wtTqvs_HWBY9cmbv5_Au0QA1Upzey_1JrQV5nHqJ-oVHUETkvMcTAauInBkwOrAUlJePqVVZdA_fyVmrzWVWgnKq_Ten9tDdZapjyJ9sgjuOqpMTTLznELj7b0-v4wNMPyw_IXlV-bMF5MzKnS49_Dd41rTK_7MDZQWIpcf7SnT64hhL1VdG2BXU6_v81WsXAKM59L8r9IjZj8XkRSIqkjA8icPr_XnToRV61UrA0LYvyNc8yGyrWIWtbxzzprTnNcFl4N4X-4-qCJQVN8fDyuH9ys-Hmqn-d9tm9Qw7wdHR5sX9wfy3WrjUq27117kneA61A3QFV7KG_Mdbene-IdC4reAfiN1T37mXXb4huqFgfIxk9dTOKi_UXqA-eUQyGnx0wHECY7e6WtKn6K53gf-9g1RrfHRT9sWp_KG5gtX2UP5pUQU27xqwqaMDAbyYOjvoqnzpu-DSjKfYM75UmRZ3V0zQ9l32Zs2nq3er6T_enVZ1PSTKG85YqDbO7e9-d7mBDB0OVUjb733M1p1EyJYknGTlQvCzz-IgTDobug-AJWGdga_tXvgQ5AdW0zGNPIG9bpkWUl2k-FmippDB71xtL9Eey4DROyjT3ZPG2cTpNa0IzHxzXcqI-CG2oYHAcn9PCvzYzHpU3yRihXjnoP8CnxTRO0tJLX71ke7Eft8_fPClfqPXax8jHcZ1Ckvppdrtp9n9JTPC0RIzFq6GPcbTDKEWfbVYic_ZA1f4JY38r6I_hOXqUvPLE_W37Rf-Cy4ngyTg9kDFOSvZGnnaKx7M45Emi3PVuvpUxiTxHTbx9K07ruCoitFpZk6y0ocqsGG0aBy-aWGa6275918-6glYHeCla0wx2PJw0sXdI6TQgszjbrxofrgpJhNwcLrg5XKg_tNxDx911KcXYMsX7JuQEH2PqqXJMi6PMSV5Ysfe8iY9_BKRMUc_1bRZwM3cW2IYOcq_5XaeVoGUDyEgEfcghJjcbKux2h-5gvQFh-qf-bt87xabvD6qHpLHlgWrKG6hQ1bkVtHspbeXvNKDw0Y0BID6K7kHQv5WdMN3Adug-QH1jSBh37mLcU_ZVhZXhSEPSQPKggFbINQFZwlZq_tRfcomjaaBacOW1QVkgfV23vWn7nge00S4PDVb7g8-oQ3BoM5vd38_m79H9-2u0_Hxz8_nrh0_v0PLDzfUduv_shq_-9g59ub79_OV-J8PtsTaxqbY55mSr2I5AAXL9UlAhanYsf6_-Ya9GRYs8n27bM86erx_eiP8_ygrH2jY_Ph-4Ij_Zkvnv47k7wS6qS1IVpKAXcBln0zSJI5JHFw-XSV3meYJJFmdTnNXlNEljgnOAKIGERvkFv8QRJlFKoigmOI0mEWS0jlkKpCYlK8ogiWBDeTOxKWgi1frC9TVeZrgophcNLaHR7n87MBbwA7mLAcZBurhQly5tud6jJGq4NnrPxXDTwOUfp6uLTjWX57dmOi3-LwAA__-e78pD">