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

Thu Apr 17 01:46:46 PDT 2025

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-expensive-checks-win` running on `as-worker-93` while building `llvm` at step 6 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/14/builds/3066

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

```
Step 6 (build-unified-tree) failure: build (failure)
...
[463/4054] Building R600GenDFAPacketizer.inc...
[464/4054] Building R600GenCallingConv.inc...
[465/4054] Building R600GenSubtargetInfo.inc...
[466/4054] Building R600GenAsmWriter.inc...
[467/4054] Building R600GenMCCodeEmitter.inc...
[468/4054] Building R600GenInstrInfo.inc...
[469/4054] Building R600GenDAGISel.inc...
[470/4054] Building AArch64GenCallingConv.inc...
[471/4054] Building AArch64GenMCCodeEmitter.inc...
[472/4054] Building AArch64GenDisassemblerTables.inc...
FAILED: lib/Target/AArch64/AArch64GenDisassemblerTables.inc C:/a/llvm-clang-x86_64-expensive-checks-win/build/lib/Target/AArch64/AArch64GenDisassemblerTables.inc 
C:\WINDOWS\system32\cmd.exe /C "cd /D C:\a\llvm-clang-x86_64-expensive-checks-win\build && C:\a\llvm-clang-x86_64-expensive-checks-win\build\bin\llvm-tblgen.exe -gen-disassembler --num-to-skip-size=3 -I C:/a/llvm-clang-x86_64-expensive-checks-win/llvm-project/llvm/lib/Target/AArch64 -IC:/a/llvm-clang-x86_64-expensive-checks-win/build/include -IC:/a/llvm-clang-x86_64-expensive-checks-win/llvm-project/llvm/include -I C:/a/llvm-clang-x86_64-expensive-checks-win/llvm-project/llvm/lib/Target --long-string-literals=0 C:/a/llvm-clang-x86_64-expensive-checks-win/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:\a\llvm-clang-x86_64-expensive-checks-win\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:\\a\\llvm-clang-x86_64-expensive-checks-win\\build\\bin\\llvm-tblgen.exe -gen-disassembler --num-to-skip-size=3 -I C:/a/llvm-clang-x86_64-expensive-checks-win/llvm-project/llvm/lib/Target/AArch64 -IC:/a/llvm-clang-x86_64-expensive-checks-win/build/include -IC:/a/llvm-clang-x86_64-expensive-checks-win/llvm-project/llvm/include -I C:/a/llvm-clang-x86_64-expensive-checks-win/llvm-project/llvm/lib/Target --long-string-literals=0 C:/a/llvm-clang-x86_64-expensive-checks-win/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 0x00007ff6b0d66ffc HandleAbort C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\lib\Support\Windows\Signals.inc:429:0
 #1 0x00007ff8f7cc90ed (C:\WINDOWS\SYSTEM32\ucrtbased.dll+0xa90ed)
 #2 0x00007ff8f7ccae49 (C:\WINDOWS\SYSTEM32\ucrtbased.dll+0xaae49)
 #3 0x00007ff8f7cd0c6f (C:\WINDOWS\SYSTEM32\ucrtbased.dll+0xb0c6f)
 #4 0x00007ff8f7cceba1 (C:\WINDOWS\SYSTEM32\ucrtbased.dll+0xaeba1)
 #5 0x00007ff8f7cd18af (C:\WINDOWS\SYSTEM32\ucrtbased.dll+0xb18af)
 #6 0x00007ff6b0973283 `anonymous namespace'::DecoderTable::patchNumToSkip C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\utils\TableGen\DecoderEmitter.cpp:150:0
 #7 0x00007ff6b097fe28 resolveTableFixups C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\utils\TableGen\DecoderEmitter.cpp:721:0
 #8 0x00007ff6b097de7c `anonymous namespace'::FilterChooser::emitSingletonTableEntry C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\utils\TableGen\DecoderEmitter.cpp:1475:0
 #9 0x00007ff6b097f6b3 `anonymous namespace'::FilterChooser::emitTableEntries C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\utils\TableGen\DecoderEmitter.cpp:1769:0
#10 0x00007ff6b097a7dd `anonymous namespace'::Filter::emitTableEntry C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\utils\TableGen\DecoderEmitter.cpp:775:0
#11 0x00007ff6b097f6c8 `anonymous namespace'::FilterChooser::emitTableEntries C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\utils\TableGen\DecoderEmitter.cpp:1771:0
#12 0x00007ff6b0976bfd `anonymous namespace'::DecoderEmitter::run C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\utils\TableGen\DecoderEmitter.cpp:2552:0
#13 0x00007ff6b0971b1b llvm::EmitDecoder(class llvm::RecordKeeper const &, class llvm::raw_ostream &, class llvm::StringRef) C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\utils\TableGen\DecoderEmitter.cpp:2584:0
#14 0x00007ff6b09ea36f emitDisassembler C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\utils\TableGen\DisassemblerEmitter.cpp:131:0
#15 0x00007ff6b04e813c llvm::function_ref<(class llvm::RecordKeeper const &, class llvm::raw_ostream &)>::callback_fn<(class llvm::RecordKeeper const &, class llvm::raw_ostream &)>(__int64, class llvm::RecordKeeper const &, class llvm::raw_ostream &) C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\include\llvm\ADT\STLFunctionalExtras.h:46:0
#16 0x00007ff6b0e549e8 llvm::function_ref<(class llvm::RecordKeeper const &, class llvm::raw_ostream &)>::operator()(class llvm::RecordKeeper const &, class llvm::raw_ostream &) const C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\include\llvm\ADT\STLFunctionalExtras.h:69:0
#17 0x00007ff6b0e5257b llvm::TableGen::Emitter::ApplyCallback(class llvm::RecordKeeper const &, class llvm::raw_ostream &) C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\lib\TableGen\TableGenBackend.cpp:69:0
#18 0x00007ff6b0e58946 llvm::TableGenMain(char const *, class std::function<(class llvm::raw_ostream &, class llvm::RecordKeeper const &)>) C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\lib\TableGen\Main.cpp:152:0
#19 0x00007ff6b0576f92 tblgen_main(int, char **) C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\utils\TableGen\Basic\TableGen.cpp:74:0
#20 0x00007ff6b0b150ac main C:\a\llvm-clang-x86_64-expensive-checks-win\llvm-project\llvm\utils\TableGen\llvm-tblgen.cpp:18:0
#21 0x00007ff6b0eedd59 invoke_main D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:79:0
#22 0x00007ff6b0eedc42 __scrt_common_main_seh D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288:0

#23 0x00007ff6b0eedafe __scrt_common_main D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:331:0

#24 0x00007ff6b0eeddee mainCRTStartup D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_main.cpp:17:0

#25 0x00007ff90f397374 (C:\WINDOWS\System32\KERNEL32.DLL+0x17374)

#26 0x00007ff90fa5cc91 (C:\WINDOWS\SYSTEM32\ntdll.dll+0x4cc91)

```

</details>

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