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

Wed Apr 16 13:43:49 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `flang-aarch64-rel-assert` running on `linaro-flang-aarch64-rel-assert` while building `llvm` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/29/builds/13130

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
42.390 [5174/26/1834] Building CXX object lib/ExecutionEngine/Orc/CMakeFiles/LLVMOrcJIT.dir/IRPartitionLayer.cpp.o
42.392 [5174/25/1835] Building CXX object lib/ExecutionEngine/Orc/CMakeFiles/LLVMOrcJIT.dir/EPCDebugObjectRegistrar.cpp.o
42.401 [5174/24/1836] Building CXX object lib/ExecutionEngine/Orc/CMakeFiles/LLVMOrcJIT.dir/JITTargetMachineBuilder.cpp.o
42.407 [5174/23/1837] Building CXX object lib/ExecutionEngine/Orc/CMakeFiles/LLVMOrcJIT.dir/JITLinkReentryTrampolines.cpp.o
42.410 [5174/22/1838] Building CXX object lib/ExecutionEngine/Orc/CMakeFiles/LLVMOrcJIT.dir/LazyObjectLinkingLayer.cpp.o
42.569 [5174/21/1839] Building AArch64GenCallingConv.inc...
42.591 [5174/20/1840] Building AArch64GenMCPseudoLowering.inc...
42.796 [5174/19/1841] Building AArch64GenO0PreLegalizeGICombiner.inc...
42.860 [5174/18/1842] Building AArch64GenPostLegalizeGICombiner.inc...
42.987 [5174/17/1843] Building AArch64GenDisassemblerTables.inc...
FAILED: lib/Target/AArch64/AArch64GenDisassemblerTables.inc /home/tcwg-buildbot/worker/flang-aarch64-rel-assert/build/lib/Target/AArch64/AArch64GenDisassemblerTables.inc 
cd /home/tcwg-buildbot/worker/flang-aarch64-rel-assert/build && /home/tcwg-buildbot/worker/flang-aarch64-rel-assert/build/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /home/tcwg-buildbot/worker/flang-aarch64-rel-assert/llvm-project/llvm/lib/Target/AArch64 -I/home/tcwg-buildbot/worker/flang-aarch64-rel-assert/build/include -I/home/tcwg-buildbot/worker/flang-aarch64-rel-assert/llvm-project/llvm/include -I /home/tcwg-buildbot/worker/flang-aarch64-rel-assert/llvm-project/llvm/lib/Target /home/tcwg-buildbot/worker/flang-aarch64-rel-assert/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: ../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/tcwg-buildbot/worker/flang-aarch64-rel-assert/build/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /home/tcwg-buildbot/worker/flang-aarch64-rel-assert/llvm-project/llvm/lib/Target/AArch64 -I/home/tcwg-buildbot/worker/flang-aarch64-rel-assert/build/include -I/home/tcwg-buildbot/worker/flang-aarch64-rel-assert/llvm-project/llvm/include -I /home/tcwg-buildbot/worker/flang-aarch64-rel-assert/llvm-project/llvm/lib/Target /home/tcwg-buildbot/worker/flang-aarch64-rel-assert/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 0x0000abeb519bce94 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/tcwg-buildbot/worker/flang-aarch64-rel-assert/build/bin/llvm-tblgen+0x32ce94)
 #1 0x0000abeb519bae94 llvm::sys::RunSignalHandlers() (/home/tcwg-buildbot/worker/flang-aarch64-rel-assert/build/bin/llvm-tblgen+0x32ae94)
 #2 0x0000abeb519bd59c SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #3 0x0000f89fad6a18f8 (linux-vdso.so.1+0x8f8)
 #4 0x0000f89fad0cf1f0 __pthread_kill_implementation ./nptl/./nptl/pthread_kill.c:44:76
 #5 0x0000f89fad08a67c gsignal ./signal/../sysdeps/posix/raise.c:27:6
 #6 0x0000f89fad077130 abort ./stdlib/./stdlib/abort.c:81:7
 #7 0x0000f89fad083fd4 __assert_fail_base ./assert/./assert/assert.c:91:7
 #8 0x0000f89fad08404c (/lib/aarch64-linux-gnu/libc.so.6+0x3404c)
 #9 0x0000abeb518587fc (anonymous namespace)::FilterChooser::emitTableEntries((anonymous namespace)::DecoderTableInfo&) const DecoderEmitter.cpp:0:0
#10 0x0000abeb51858668 (anonymous namespace)::FilterChooser::emitTableEntries((anonymous namespace)::DecoderTableInfo&) const DecoderEmitter.cpp:0:0
#11 0x0000abeb5185491c (anonymous namespace)::DecoderEmitter::run(llvm::raw_ostream&) DecoderEmitter.cpp:0:0
#12 0x0000abeb51850498 llvm::EmitDecoder(llvm::RecordKeeper const&, llvm::raw_ostream&, llvm::StringRef) (/home/tcwg-buildbot/worker/flang-aarch64-rel-assert/build/bin/llvm-tblgen+0x1c0498)
#13 0x0000abeb5186f724 emitDisassembler(llvm::RecordKeeper const&, llvm::raw_ostream&) DisassemblerEmitter.cpp:0:0
#14 0x0000abeb519f0954 llvm::TableGen::Emitter::ApplyCallback(llvm::RecordKeeper const&, llvm::raw_ostream&) (/home/tcwg-buildbot/worker/flang-aarch64-rel-assert/build/bin/llvm-tblgen+0x360954)
#15 0x0000abeb519cbd74 llvm::TableGenMain(char const*, std::function<bool (llvm::raw_ostream&, llvm::RecordKeeper const&)>) (/home/tcwg-buildbot/worker/flang-aarch64-rel-assert/build/bin/llvm-tblgen+0x33bd74)
#16 0x0000abeb516e719c tblgen_main(int, char**) (/home/tcwg-buildbot/worker/flang-aarch64-rel-assert/build/bin/llvm-tblgen+0x5719c)
#17 0x0000f89fad0773fc __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3
#18 0x0000f89fad0774cc call_init ./csu/../csu/libc-start.c:128:20
#19 0x0000f89fad0774cc __libc_start_main ./csu/../csu/libc-start.c:379:5
#20 0x0000abeb516b0d30 _start (/home/tcwg-buildbot/worker/flang-aarch64-rel-assert/build/bin/llvm-tblgen+0x20d30)
Aborted
42.989 [5174/16/1844] Building AArch64GenPostLegalizeGILowering.inc...
43.046 [5174/15/1845] Building AArch64GenAsmWriter1.inc...
43.064 [5174/14/1846] Building AArch64GenMCCodeEmitter.inc...
43.104 [5174/13/1847] Building AArch64GenAsmWriter.inc...
43.118 [5174/12/1848] Building AArch64GenSystemOperands.inc...
43.171 [5174/11/1849] Building AArch64GenRegisterBank.inc...
43.242 [5174/10/1850] Building AArch64GenExegesis.inc...
43.382 [5174/9/1851] Building AArch64GenPreLegalizeGICombiner.inc...
43.464 [5174/8/1852] Building AArch64GenAsmMatcher.inc...
43.611 [5174/7/1853] Building AArch64GenRegisterInfo.inc...
44.353 [5174/6/1854] Building AArch64GenFastISel.inc...

```

</details>

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