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

Wed Apr 16 15:10:10 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-ppc64le-rhel` running on `ppc64le-clang-rhel-test` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/145/builds/6406

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
31.570 [3213/192/3100] Building CXX object lib/Target/Mips/CMakeFiles/LLVMMipsCodeGen.dir/MipsTargetTransformInfo.cpp.o
31.580 [3212/192/3101] Building CXX object lib/Target/Mips/CMakeFiles/LLVMMipsCodeGen.dir/MipsMulMulBugPass.cpp.o
31.588 [3211/192/3102] Building CXX object lib/Target/Mips/AsmParser/CMakeFiles/LLVMMipsAsmParser.dir/MipsAsmParser.cpp.o
31.609 [3210/192/3103] Building CXX object lib/Target/Mips/MCTargetDesc/CMakeFiles/LLVMMipsDesc.dir/MipsNaClELFStreamer.cpp.o
31.624 [3209/192/3104] Building CXX object lib/Target/XCore/CMakeFiles/LLVMXCoreCodeGen.dir/XCoreFrameLowering.cpp.o
31.630 [3208/192/3105] Building CXX object lib/Target/XCore/CMakeFiles/LLVMXCoreCodeGen.dir/XCoreInstrInfo.cpp.o
31.634 [3207/192/3106] Building CXX object lib/Target/XCore/CMakeFiles/LLVMXCoreCodeGen.dir/XCoreLowerThreadLocal.cpp.o
31.641 [3206/192/3107] Building CXX object lib/Target/XCore/CMakeFiles/LLVMXCoreCodeGen.dir/XCoreMachineFunctionInfo.cpp.o
31.649 [3205/192/3108] Building CXX object lib/Target/WebAssembly/CMakeFiles/LLVMWebAssemblyCodeGen.dir/WebAssemblyAddMissingPrototypes.cpp.o
31.658 [3204/192/3109] Building AArch64GenDisassemblerTables.inc...
FAILED: lib/Target/AArch64/AArch64GenDisassemblerTables.inc /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/lib/Target/AArch64/AArch64GenDisassemblerTables.inc 
cd /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build && /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/lib/Target/AArch64 -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/include -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/include -I /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/lib/Target /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/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-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/utils/TableGen/DecoderEmitter.cpp:151: void (anonymous namespace)::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-rhel-test/clang-ppc64le-rhel/build/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/lib/Target/AArch64 -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/include -I/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/include -I /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/lib/Target /home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/llvm/lib/Target/AArch64/AArch64.td --write-if-changed -o lib/Target/AArch64/AArch64GenDisassemblerTables.inc -d lib/Target/AArch64/AArch64GenDisassemblerTables.inc.d
 #0 0x00007ae60234d88c llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/bin/../lib/libLLVMSupport.so.21.0git+0x29d88c)
 #1 0x00007ae60234dfe4 PrintStackTraceSignalHandler(void*) Signals.cpp:0:0
 #2 0x00007ae60234a9a0 llvm::sys::RunSignalHandlers() (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/bin/../lib/libLLVMSupport.so.21.0git+0x29a9a0)
 #3 0x00007ae60234e2bc SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #4 0x00007ae6025404c8 (linux-vdso64.so.1+0x4c8)
 #5 0x00007ae601b2a448 raise (/lib64/libc.so.6+0x4a448)
 #6 0x00007ae601b04a54 abort (/lib64/libc.so.6+0x24a54)
 #7 0x00007ae601b1dc30 __assert_fail_base (/lib64/libc.so.6+0x3dc30)
 #8 0x00007ae601b1dcd4 __assert_fail (/lib64/libc.so.6+0x3dcd4)
 #9 0x000007f54925973c (anonymous namespace)::DecoderTable::patchNumToSkip(unsigned long, unsigned int) DecoderEmitter.cpp:0:0
#10 0x000007f54924f0b0 (anonymous namespace)::FilterChooser::emitTableEntries((anonymous namespace)::DecoderTableInfo&) const DecoderEmitter.cpp:0:0
#11 0x000007f54924f9d4 (anonymous namespace)::FilterChooser::emitTableEntries((anonymous namespace)::DecoderTableInfo&) const DecoderEmitter.cpp:0:0
#12 0x000007f54924b098 (anonymous namespace)::DecoderEmitter::run(llvm::raw_ostream&) DecoderEmitter.cpp:0:0
#13 0x000007f54924631c llvm::EmitDecoder(llvm::RecordKeeper const&, llvm::raw_ostream&, llvm::StringRef) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/bin/llvm-tblgen+0x32631c)
#14 0x000007f54926daec emitDisassembler(llvm::RecordKeeper const&, llvm::raw_ostream&) DisassemblerEmitter.cpp:0:0
#15 0x000007f5490449cc 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&) ARMTargetDefEmitter.cpp:0:0
#16 0x00007ae6024a63d4 llvm::TableGen::Emitter::ApplyCallback(llvm::RecordKeeper const&, llvm::raw_ostream&) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/bin/../lib/libLLVMTableGen.so.21.0git+0x863d4)
#17 0x00007ae60246c1b8 llvm::TableGenMain(char const*, std::function<bool (llvm::raw_ostream&, llvm::RecordKeeper const&)>) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/bin/../lib/libLLVMTableGen.so.21.0git+0x4c1b8)
#18 0x000007f54907b1a8 tblgen_main(int, char**) (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/bin/llvm-tblgen+0x15b1a8)
#19 0x000007f549301ff8 main (/home/buildbots/llvm-external-buildbots/workers/ppc64le-clang-rhel-test/clang-ppc64le-rhel/build/bin/llvm-tblgen+0x3e1ff8)
#20 0x00007ae601b0a96c generic_start_main.isra.0 (/lib64/libc.so.6+0x2a96c)
#21 0x00007ae601b0ab04 __libc_start_main (/lib64/libc.so.6+0x2ab04)
31.660 [3204/191/3110] Building ARMGenSubtargetInfo.inc...
31.664 [3204/190/3111] Building CXX object lib/Target/Mips/CMakeFiles/LLVMMipsCodeGen.dir/MipsTargetMachine.cpp.o
31.670 [3204/189/3112] Building CXX object lib/Target/XCore/CMakeFiles/LLVMXCoreCodeGen.dir/XCoreISelDAGToDAG.cpp.o
31.676 [3204/188/3113] Building CXX object lib/Target/XCore/CMakeFiles/LLVMXCoreCodeGen.dir/XCoreISelLowering.cpp.o
31.680 [3204/187/3114] Building CXX object lib/Target/XCore/CMakeFiles/LLVMXCoreCodeGen.dir/XCoreMCInstLower.cpp.o
31.683 [3204/186/3115] Building CXX object lib/Target/XCore/CMakeFiles/LLVMXCoreCodeGen.dir/XCoreSubtarget.cpp.o
31.687 [3204/185/3116] Building CXX object lib/Target/WebAssembly/CMakeFiles/LLVMWebAssemblyCodeGen.dir/WebAssemblyArgumentMove.cpp.o
31.691 [3204/184/3117] Building CXX object lib/Target/WebAssembly/CMakeFiles/LLVMWebAssemblyCodeGen.dir/WebAssemblyCFGSort.cpp.o
31.694 [3204/183/3118] Building CXX object lib/Target/WebAssembly/CMakeFiles/LLVMWebAssemblyCodeGen.dir/WebAssemblyDebugValueManager.cpp.o
31.697 [3204/182/3119] Building CXX object lib/Target/WebAssembly/CMakeFiles/LLVMWebAssemblyCodeGen.dir/WebAssemblyFixFunctionBitcasts.cpp.o
31.699 [3204/181/3120] Linking CXX shared library lib/libLLVMMSP430Desc.so.21.0git

```

</details>

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