[llvm] [TableGen] Introduce MatcherList to manage a linked list of Matchers. NFC (PR #177875)

Fri Feb 13 17:59:47 PST 2026

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `cross-project-tests-sie-ubuntu` running on `doug-worker-1a` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/181/builds/37142

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
14.455 [401/8/53] Building X86GenDisassemblerTables.inc...
15.453 [400/8/54] Building X86GenFoldTables.inc...
17.153 [399/8/55] Building X86GenFastISel.inc...
17.541 [398/8/56] Building X86GenInstrMapping.inc...
18.456 [397/8/57] Building X86GenMnemonicTables.inc...
18.466 [396/8/58] Building Options.inc...
18.475 [393/8/59] Building Options.inc...
18.621 [390/8/60] Building Options.inc...
18.658 [285/8/61] Generating VCSVersion.inc
18.796 [284/8/62] Building X86GenDAGISel.inc...
FAILED: lib/Target/X86/X86GenDAGISel.inc /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/lib/Target/X86/X86GenDAGISel.inc 
cd /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/lib/Target/X86 && /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/bin/llvm-tblgen -gen-dag-isel -I/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/lib/Target/X86 -I/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/include -I/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/include -I /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/lib/Target -omit-comments /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/lib/Target/X86/X86.td --write-if-changed -o X86GenDAGISel.inc -d X86GenDAGISel.inc.d && /usr/bin/cmake/bin/cmake -E cmake_transform_depfile Ninja gccdepfile /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/lib/Target/X86 /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/lib/Target/X86 /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/lib/Target/X86/X86GenDAGISel.inc.d /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/CMakeFiles/d/412f3d6c12df01f7bfaceb66c5210be656feb1d9868b0ebbefcdc7e929649e44.d
llvm-tblgen: /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/include/llvm/Support/Casting.h:109: static bool llvm::isa_impl_cl<To, const From*>::doit(const From*) [with To = llvm::ScopeMatcher; From = llvm::Matcher]: Assertion `Val && "isa<> used on a null pointer"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug.
Stack dump:
0.	Program arguments: /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/bin/llvm-tblgen -gen-dag-isel -I/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/lib/Target/X86 -I/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/include -I/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/include -I /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/lib/Target -omit-comments /home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/llvm-project/llvm/lib/Target/X86/X86.td --write-if-changed -o X86GenDAGISel.inc -d X86GenDAGISel.inc.d
 #0 0x0000648bc8f9ad7f llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/bin/llvm-tblgen+0x3a1d7f)
 #1 0x0000648bc8f97d14 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #2 0x00007dbb76564420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
 #3 0x00007dbb7604f00b raise /build/glibc-B3wQXB/glibc-2.31/signal/../sysdeps/unix/sysv/linux/raise.c:51:1
 #4 0x00007dbb7602e859 abort /build/glibc-B3wQXB/glibc-2.31/stdlib/abort.c:81:7
 #5 0x00007dbb7602e729 get_sysdep_segment_value /build/glibc-B3wQXB/glibc-2.31/intl/loadmsgcat.c:509:8
 #6 0x00007dbb7602e729 _nl_load_domain /build/glibc-B3wQXB/glibc-2.31/intl/loadmsgcat.c:970:34
 #7 0x00007dbb7603ffd6 (/lib/x86_64-linux-gnu/libc.so.6+0x33fd6)
 #8 0x0000648bc8e04735 (/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/bin/llvm-tblgen+0x20b735)
 #9 0x0000648bc8e06f91 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#10 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#11 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#12 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#13 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#14 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#15 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#16 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#17 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#18 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#19 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#20 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#21 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#22 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#23 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#24 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#25 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#26 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#27 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#28 0x0000648bc8e06398 FactorScope(llvm::MatcherList&, llvm::MatcherList::iterator_impl<false>) DAGISelMatcherOpt.cpp:0:0
#29 0x0000648bc8dddc14 llvm::TableGen::Emitter::OptClass<(anonymous namespace)::DAGISelEmitter>::run(llvm::StringRef, llvm::RecordKeeper const&) DAGISelEmitter.cpp:0:0
#30 0x0000648bc8fd6a11 llvm::TableGen::Emitter::ApplyCallback(llvm::RecordKeeper const&, llvm::TableGenOutputFiles&, llvm::StringRef) (/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/bin/llvm-tblgen+0x3dda11)
#31 0x0000648bc8fa55fb llvm::TableGenMain(char const*, llvm::function_ref<bool (llvm::TableGenOutputFiles&, llvm::RecordKeeper const&)>) (/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/bin/llvm-tblgen+0x3ac5fb)
#32 0x0000648bc8c66c05 tblgen_main(int, char**) (/home/buildbot/buildbot-root/cross-project-tests-sie-ubuntu/build/bin/llvm-tblgen+0x6dc05)

```

</details>

https://github.com/llvm/llvm-project/pull/177875