[llvm] [LLVM][TableGen] Parameterize NumToSkip in DecoderEmitter (PR #135882)

Wed Apr 16 14:24:38 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-ppc64le-linux-multistage` running on `ppc64le-clang-multistage-test` while building `llvm` at step 4 "build stage 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/76/builds/8802

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

```
Step 4 (build stage 1) failure: 'ninja' (failure)
...
[4806/6368] Building CXX object lib/Target/NVPTX/CMakeFiles/LLVMNVPTXCodeGen.dir/NVPTXTargetMachine.cpp.o
[4807/6368] Building CXX object lib/Target/NVPTX/CMakeFiles/LLVMNVPTXCodeGen.dir/NVPTXTargetTransformInfo.cpp.o
[4808/6368] Building CXX object lib/Target/NVPTX/CMakeFiles/LLVMNVPTXCodeGen.dir/NVPTXUtilities.cpp.o
[4809/6368] Building CXX object lib/Target/NVPTX/CMakeFiles/LLVMNVPTXCodeGen.dir/NVVMIntrRange.cpp.o
[4810/6368] Building CXX object lib/Target/NVPTX/CMakeFiles/LLVMNVPTXCodeGen.dir/NVVMReflect.cpp.o
[4811/6368] Building CXX object lib/Target/NVPTX/CMakeFiles/LLVMNVPTXCodeGen.dir/NVPTXProxyRegErasure.cpp.o
[4812/6368] Building CXX object lib/Target/NVPTX/CMakeFiles/LLVMNVPTXCodeGen.dir/NVPTXCtorDtorLowering.cpp.o
[4813/6368] Linking CXX shared library lib/libLLVMLoongArchInfo.so.21.0git
[4814/6368] Building AArch64GenAsmMatcher.inc...
[4815/6368] Building AArch64GenDisassemblerTables.inc...
FAILED: lib/Target/AArch64/AArch64GenDisassemblerTables.inc /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/lib/Target/AArch64/AArch64GenDisassemblerTables.inc 
cd /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1 && /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/lib/Target/AArch64 -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/include -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/include -I /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/lib/Target /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/lib/Target/AArch64/AArch64.td --write-if-changed -o lib/Target/AArch64/AArch64GenDisassemblerTables.inc -d lib/Target/AArch64/AArch64GenDisassemblerTables.inc.d
llvm-tblgen: /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/utils/TableGen/DecoderEmitter.cpp:151: void {anonymous}::DecoderTable::patchNumToSkip(size_t, uint32_t): Assertion `DestIdx > FixupIdx + NumToSkipSizeInBytes && "Expecting a forward jump in the decoding table"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/lib/Target/AArch64 -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/include -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/include -I /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/lib/Target /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/llvm/llvm/lib/Target/AArch64/AArch64.td --write-if-changed -o lib/Target/AArch64/AArch64GenDisassemblerTables.inc -d lib/Target/AArch64/AArch64GenDisassemblerTables.inc.d
 #0 0x00007fff908b3f60 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/../lib/libLLVMSupport.so.21.0git+0x253f60)
 #1 0x00007fff908b0ca4 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #2 0x00007fff90b204d8 (linux-vdso64.so.1+0x4d8)
 #3 0x00007fff900da4c8 raise (/lib64/libc.so.6+0x4a4c8)
 #4 0x00007fff900b4a54 abort (/lib64/libc.so.6+0x24a54)
 #5 0x00007fff900cdcb0 __assert_fail_base (/lib64/libc.so.6+0x3dcb0)
 #6 0x00007fff900cdd54 __assert_fail (/lib64/libc.so.6+0x3dd54)
 #7 0x00000000101fadfc (anonymous namespace)::DecoderTable::patchNumToSkip(unsigned long, unsigned int) DecoderEmitter.cpp:0:0
 #8 0x0000000010205fb0 (anonymous namespace)::FilterChooser::emitTableEntries((anonymous namespace)::DecoderTableInfo&) const DecoderEmitter.cpp:0:0
 #9 0x0000000010205a2c (anonymous namespace)::FilterChooser::emitTableEntries((anonymous namespace)::DecoderTableInfo&) const DecoderEmitter.cpp:0:0
#10 0x00000000102078d8 llvm::EmitDecoder(llvm::RecordKeeper const&, llvm::raw_ostream&, llvm::StringRef) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/llvm-tblgen+0x102078d8)
#11 0x000000001021e780 emitDisassembler(llvm::RecordKeeper const&, llvm::raw_ostream&) DisassemblerEmitter.cpp:0:0
#12 0x0000000010010fdc void llvm::function_ref<void (llvm::RecordKeeper const&, llvm::raw_ostream&)>::callback_fn<void (llvm::RecordKeeper const&, llvm::raw_ostream&)>(long, llvm::RecordKeeper const&, llvm::raw_ostream&) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/llvm-tblgen+0x10010fdc)
#13 0x00007fff90a73258 llvm::TableGen::Emitter::ApplyCallback(llvm::RecordKeeper const&, llvm::raw_ostream&) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/../lib/libLLVMTableGen.so.21.0git+0x63258)
#14 0x00007fff90a33f68 llvm::TableGenMain(char const*, std::function<bool (llvm::raw_ostream&, llvm::RecordKeeper const&)>) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/../lib/libLLVMTableGen.so.21.0git+0x23f68)
#15 0x000000001004b3cc tblgen_main(int, char**) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/llvm-tblgen+0x1004b3cc)
#16 0x000000001000fe48 main (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-multistage-test/clang-ppc64le-multistage/stage1/bin/llvm-tblgen+0x1000fe48)
#17 0x00007fff900ba9ec generic_start_main.isra.0 (/lib64/libc.so.6+0x2a9ec)
#18 0x00007fff900bab84 __libc_start_main (/lib64/libc.so.6+0x2ab84)
[4816/6368] Building RISCVGenRegisterBank.inc...
[4817/6368] Building CXX object tools/clang/tools/extra/clang-tidy/modernize/CMakeFiles/obj.clangTidyModernizeModule.dir/DeprecatedHeadersCheck.cpp.o
[4818/6368] Building CXX object tools/clang/tools/extra/clang-tidy/modernize/CMakeFiles/obj.clangTidyModernizeModule.dir/ReplaceAutoPtrCheck.cpp.o
[4819/6368] Building CXX object tools/clang/tools/extra/clang-tidy/llvm/CMakeFiles/obj.clangTidyLLVMModule.dir/HeaderGuardCheck.cpp.o
[4820/6368] Building CXX object tools/clang/tools/extra/clang-tidy/llvm/CMakeFiles/obj.clangTidyLLVMModule.dir/IncludeOrderCheck.cpp.o
[4821/6368] Building CXX object tools/clang/tools/extra/clang-tidy/mpi/CMakeFiles/obj.clangTidyMPIModule.dir/MPITidyModule.cpp.o
[4822/6368] Building CXX object tools/clang/tools/extra/clang-doc/CMakeFiles/obj.clangDoc.dir/Generators.cpp.o
[4823/6368] Building CXX object tools/clang/tools/clang-import-test/CMakeFiles/clang-import-test.dir/clang-import-test.cpp.o
[4824/6368] Building CXX object tools/clang/tools/clang-refactor/CMakeFiles/clang-refactor.dir/ClangRefactor.cpp.o
[4825/6368] Linking CXX shared library lib/libLLVMMipsInfo.so.21.0git
[4826/6368] Linking CXX shared library lib/libLLVMSystemZInfo.so.21.0git
[4827/6368] Linking CXX shared library lib/libLLVMVEInfo.so.21.0git
[4828/6368] Creating library symlink lib/libLLVMLanaiInfo.so
[4829/6368] Creating library symlink lib/libLLVMWebAssemblyInfo.so

```

</details>

https://github.com/llvm/llvm-project/pull/135882