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

Wed Apr 16 13:19:05 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `lldb-remote-linux-win` running on `as-builder-10` while building `llvm` at step 8 "build-default".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/197/builds/4102

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

```
Step 8 (build-default) failure: cmake (failure)
...
12.302 [2461/130/2837]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaLoongArch.cpp.obj
12.309 [2460/130/2838]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaOpenCL.cpp.obj
12.317 [2459/130/2839]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaLambda.cpp.obj
12.326 [2458/130/2840]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaNVPTX.cpp.obj
12.330 [2457/130/2841]Building AArch64GenSystemOperands.inc...
12.338 [2456/130/2842]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaInit.cpp.obj
12.360 [2455/130/2843]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaOpenACC.cpp.obj
12.366 [2454/130/2844]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaPPC.cpp.obj
12.372 [2453/130/2845]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaOverload.cpp.obj
12.384 [2452/130/2846]Building AArch64GenDisassemblerTables.inc...
FAILED: lib/Target/AArch64/AArch64GenDisassemblerTables.inc C:/buildbot/as-builder-10/lldb-x-aarch64/build/lib/Target/AArch64/AArch64GenDisassemblerTables.inc 
cmd.exe /C "cd /D C:\buildbot\as-builder-10\lldb-x-aarch64\build && C:\buildbot\as-builder-10\lldb-x-aarch64\build\bin\llvm-tblgen.exe -gen-disassembler --num-to-skip-size=3 -I C:/buildbot/as-builder-10/lldb-x-aarch64/llvm-project/llvm/lib/Target/AArch64 -IC:/buildbot/as-builder-10/lldb-x-aarch64/build/include -IC:/buildbot/as-builder-10/lldb-x-aarch64/llvm-project/llvm/include -I C:/buildbot/as-builder-10/lldb-x-aarch64/llvm-project/llvm/lib/Target --long-string-literals=0 C:/buildbot/as-builder-10/lldb-x-aarch64/llvm-project/llvm/lib/Target/AArch64/AArch64.td --write-if-changed -o lib/Target/AArch64/AArch64GenDisassemblerTables.inc -d lib/Target/AArch64/AArch64GenDisassemblerTables.inc.d"
Assertion failed: DestIdx > FixupIdx + NumToSkipSizeInBytes && "Expecting a forward jump in the decoding table", file C:\buildbot\as-builder-10\lldb-x-aarch64\llvm-project\llvm\utils\TableGen\DecoderEmitter.cpp, line 151
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: C:\\buildbot\\as-builder-10\\lldb-x-aarch64\\build\\bin\\llvm-tblgen.exe -gen-disassembler --num-to-skip-size=3 -I C:/buildbot/as-builder-10/lldb-x-aarch64/llvm-project/llvm/lib/Target/AArch64 -IC:/buildbot/as-builder-10/lldb-x-aarch64/build/include -IC:/buildbot/as-builder-10/lldb-x-aarch64/llvm-project/llvm/include -I C:/buildbot/as-builder-10/lldb-x-aarch64/llvm-project/llvm/lib/Target --long-string-literals=0 C:/buildbot/as-builder-10/lldb-x-aarch64/llvm-project/llvm/lib/Target/AArch64/AArch64.td --write-if-changed -o lib/Target/AArch64/AArch64GenDisassemblerTables.inc -d lib/Target/AArch64/AArch64GenDisassemblerTables.inc.d
Exception Code: 0x80000003
 #0 0x00007ff7aeb2c5d5 (C:\buildbot\as-builder-10\lldb-x-aarch64\build\bin\llvm-tblgen.exe+0x2ec5d5)
 #1 0x00007ffb08a0bb04 (C:\Windows\System32\ucrtbase.dll+0x7bb04)
 #2 0x00007ffb08a0cad1 (C:\Windows\System32\ucrtbase.dll+0x7cad1)
 #3 0x00007ffb08a0e4a1 (C:\Windows\System32\ucrtbase.dll+0x7e4a1)
 #4 0x00007ffb08a0e6e1 (C:\Windows\System32\ucrtbase.dll+0x7e6e1)
 #5 0x00007ff7ae9ecf07 (C:\buildbot\as-builder-10\lldb-x-aarch64\build\bin\llvm-tblgen.exe+0x1acf07)
 #6 0x00007ff7ae9e7b32 (C:\buildbot\as-builder-10\lldb-x-aarch64\build\bin\llvm-tblgen.exe+0x1a7b32)
 #7 0x00007ff7ae9e834f (C:\buildbot\as-builder-10\lldb-x-aarch64\build\bin\llvm-tblgen.exe+0x1a834f)
 #8 0x00007ff7ae9ee210 (C:\buildbot\as-builder-10\lldb-x-aarch64\build\bin\llvm-tblgen.exe+0x1ae210)
 #9 0x00007ff7ae9e1871 (C:\buildbot\as-builder-10\lldb-x-aarch64\build\bin\llvm-tblgen.exe+0x1a1871)
#10 0x00007ff7ae9fb7e4 (C:\buildbot\as-builder-10\lldb-x-aarch64\build\bin\llvm-tblgen.exe+0x1bb7e4)
#11 0x00007ff7aeb61927 (C:\buildbot\as-builder-10\lldb-x-aarch64\build\bin\llvm-tblgen.exe+0x321927)
#12 0x00007ff7aeb65703 (C:\buildbot\as-builder-10\lldb-x-aarch64\build\bin\llvm-tblgen.exe+0x325703)
#13 0x00007ff7ae87f895 (C:\buildbot\as-builder-10\lldb-x-aarch64\build\bin\llvm-tblgen.exe+0x3f895)

#14 0x00007ff7aeb91e64 (C:\buildbot\as-builder-10\lldb-x-aarch64\build\bin\llvm-tblgen.exe+0x351e64)

#15 0x00007ffb09f84cb0 (C:\Windows\System32\KERNEL32.DLL+0x14cb0)

#16 0x00007ffb0abfedcb (C:\Windows\SYSTEM32\ntdll.dll+0x7edcb)

12.390 [2452/129/2847]Building AArch64GenO0PreLegalizeGICombiner.inc...
12.393 [2452/128/2848]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\TypeLocBuilder.cpp.obj
12.395 [2452/127/2849]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaStmtAttr.cpp.obj
12.401 [2452/126/2850]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaSwift.cpp.obj
12.414 [2452/125/2851]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaSPIRV.cpp.obj
12.427 [2452/124/2852]Building AArch64GenAsmWriter1.inc...
12.442 [2452/123/2853]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaTemplateVariadic.cpp.obj
12.446 [2452/122/2854]Building AArch64GenPreLegalizeGICombiner.inc...
12.459 [2452/121/2855]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaSystemZ.cpp.obj
12.482 [2452/120/2856]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaX86.cpp.obj
12.508 [2452/119/2857]Building CXX object tools\clang\lib\Sema\CMakeFiles\obj.clangSema.dir\SemaWasm.cpp.obj

```

</details>

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