[flang-commits] [flang] [flang] Fix crash when handling benign USE conflict (PR #121977)

[LLVM Continuous Integration via flang-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `premerge-monolithic-linux` running on `premerge-linux-1` while building `flang` at step 7 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/153/builds/19156

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 7 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: ExecutionEngine/JITLink/x86-64/ELF_perf.s' FAILED ********************
Exit Code: 134

Command Output (stderr):
--
RUN: at line 6: rm -rf /build/buildbot/premerge-monolithic-linux/build/test/ExecutionEngine/JITLink/x86-64/Output/ELF_perf.s.tmp && mkdir -p /build/buildbot/premerge-monolithic-linux/build/test/ExecutionEngine/JITLink/x86-64/Output/ELF_perf.s.tmp
+ rm -rf /build/buildbot/premerge-monolithic-linux/build/test/ExecutionEngine/JITLink/x86-64/Output/ELF_perf.s.tmp
+ mkdir -p /build/buildbot/premerge-monolithic-linux/build/test/ExecutionEngine/JITLink/x86-64/Output/ELF_perf.s.tmp
RUN: at line 7: /build/buildbot/premerge-monolithic-linux/build/bin/llvm-mc -triple=x86_64-unknown-linux -position-independent      -filetype=obj -o /build/buildbot/premerge-monolithic-linux/build/test/ExecutionEngine/JITLink/x86-64/Output/ELF_perf.s.tmp/ELF_x86-64_perf.o /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/ExecutionEngine/JITLink/x86-64/ELF_perf.s
+ /build/buildbot/premerge-monolithic-linux/build/bin/llvm-mc -triple=x86_64-unknown-linux -position-independent -filetype=obj -o /build/buildbot/premerge-monolithic-linux/build/test/ExecutionEngine/JITLink/x86-64/Output/ELF_perf.s.tmp/ELF_x86-64_perf.o /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/test/ExecutionEngine/JITLink/x86-64/ELF_perf.s
RUN: at line 9: env JITDUMPDIR="/build/buildbot/premerge-monolithic-linux/build/test/ExecutionEngine/JITLink/x86-64/Output/ELF_perf.s.tmp" /build/buildbot/premerge-monolithic-linux/build/bin/llvm-jitlink -perf-support      /build/buildbot/premerge-monolithic-linux/build/test/ExecutionEngine/JITLink/x86-64/Output/ELF_perf.s.tmp/ELF_x86-64_perf.o
+ env JITDUMPDIR=/build/buildbot/premerge-monolithic-linux/build/test/ExecutionEngine/JITLink/x86-64/Output/ELF_perf.s.tmp /build/buildbot/premerge-monolithic-linux/build/bin/llvm-jitlink -perf-support /build/buildbot/premerge-monolithic-linux/build/test/ExecutionEngine/JITLink/x86-64/Output/ELF_perf.s.tmp/ELF_x86-64_perf.o
Writing unwind record with unwind data size 104 and EH frame header size 12 and mapped size 0
llvm-jitlink: /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/include/llvm/ExecutionEngine/Orc/SymbolStringPool.h:285: llvm::orc::SymbolStringPool::~SymbolStringPool(): Assertion `Pool.empty() && "Dangling references at pool destruction time"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /build/buildbot/premerge-monolithic-linux/build/bin/llvm-jitlink -perf-support /build/buildbot/premerge-monolithic-linux/build/test/ExecutionEngine/JITLink/x86-64/Output/ELF_perf.s.tmp/ELF_x86-64_perf.o
 #0 0x00005a0e1d984308 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/Support/Unix/Signals.inc:723:13
 #1 0x00005a0e1d981ebe llvm::sys::RunSignalHandlers() /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/Support/Signals.cpp:106:18
 #2 0x00005a0e1d9849b8 SignalHandler(int) /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/Support/Unix/Signals.inc:413:1
 #3 0x00007861c9825520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x00007861c98799fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #5 0x00007861c9825476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #6 0x00007861c980b7f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #7 0x00007861c980b71b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #8 0x00007861c981ce96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #9 0x00005a0e1d2010ac (/build/buildbot/premerge-monolithic-linux/build/bin/llvm-jitlink+0x23080ac)
#10 0x00005a0e1d866868 __is_single_threaded /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/ext/atomicity.h:52:12
#11 0x00005a0e1d866868 __exchange_and_add_dispatch /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/ext/atomicity.h:98:9
#12 0x00005a0e1d866868 _M_release /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/shared_ptr_base.h:180:10
#13 0x00005a0e1d866868 ~__shared_count /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/shared_ptr_base.h:705:11
#14 0x00005a0e1d866868 ~__shared_ptr /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/shared_ptr_base.h:1154:31
#15 0x00005a0e1d866868 llvm::orc::ExecutorProcessControl::~ExecutorProcessControl() /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/ExecutionEngine/Orc/ExecutorProcessControl.cpp:27:49
#16 0x00005a0e1d867fbf llvm::orc::SelfExecutorProcessControl::~SelfExecutorProcessControl() /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/include/llvm/ExecutionEngine/Orc/ExecutorProcessControl.h:467:7
#17 0x00005a0e1d7893ff ~unique_ptr /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/unique_ptr.h:362:8
#18 0x00005a0e1d7893ff llvm::orc::ExecutionSession::~ExecutionSession() /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/lib/ExecutionEngine/Orc/Core.cpp:1600:1
#19 0x00005a0e1d1da4ed llvm::Session::~Session() /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/tools/llvm-jitlink/llvm-jitlink.cpp:1033:1
#20 0x00005a0e1d1e4c08 operator() /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/unique_ptr.h:85:2
#21 0x00005a0e1d1e4c08 reset /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/unique_ptr.h:182:4
#22 0x00005a0e1d1e4c08 reset /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/unique_ptr.h:456:7
#23 0x00005a0e1d1e4c08 main /build/buildbot/premerge-monolithic-linux/llvm-project/llvm/tools/llvm-jitlink/llvm-jitlink.cpp:2584:5
#24 0x00007861c980cd90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#25 0x00007861c980ce40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#26 0x00005a0e1d1d2b65 _start (/build/buildbot/premerge-monolithic-linux/build/bin/llvm-jitlink+0x22d9b65)
/build/buildbot/premerge-monolithic-linux/build/test/ExecutionEngine/JITLink/x86-64/Output/ELF_perf.s.script: line 4: 2582688 Aborted                 env JITDUMPDIR="/build/buildbot/premerge-monolithic-linux/build/test/ExecutionEngine/JITLink/x86-64/Output/ELF_perf.s.tmp" /build/buildbot/premerge-monolithic-linux/build/bin/llvm-jitlink -perf-support /build/buildbot/premerge-monolithic-linux/build/test/ExecutionEngine/JITLink/x86-64/Output/ELF_perf.s.tmp/ELF_x86-64_perf.o

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/121977