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

Wed Apr 16 14:13:42 PDT 2025

llvm-ci wrote:

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

Full details are available at: https://lab.llvm.org/buildbot/#/builders/130/builds/12480

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
149.077 [5460/22/1913] Building AArch64GenExegesis.inc...
149.103 [5460/21/1914] Building AArch64GenMCPseudoLowering.inc...
149.307 [5460/20/1915] Building AArch64GenPreLegalizeGICombiner.inc...
149.307 [5460/19/1916] Building AArch64GenO0PreLegalizeGICombiner.inc...
149.308 [5460/18/1917] Building AArch64GenPostLegalizeGILowering.inc...
149.309 [5460/17/1918] Building AArch64GenPostLegalizeGICombiner.inc...
149.379 [5460/16/1919] Building AArch64GenSystemOperands.inc...
149.445 [5460/15/1920] Building AArch64GenMCCodeEmitter.inc...
149.548 [5460/14/1921] Building AArch64GenAsmWriter1.inc...
149.572 [5460/13/1922] Building AArch64GenDisassemblerTables.inc...
FAILED: lib/Target/AArch64/AArch64GenDisassemblerTables.inc /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build/lib/Target/AArch64/AArch64GenDisassemblerTables.inc 
cd /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build && /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/llvm-project/llvm/lib/Target/AArch64 -I/home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build/include -I/home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/llvm-project/llvm/include -I /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/llvm-project/llvm/lib/Target /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/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:150: 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/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/llvm-project/llvm/lib/Target/AArch64 -I/home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build/include -I/home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/llvm-project/llvm/include -I /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/llvm-project/llvm/lib/Target /home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/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 0x0000fc3b9a5d07d4 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build/bin/../lib/libLLVMSupport.so.21.0git+0x1d07d4)
 #1 0x0000fc3b9a5cdf40 llvm::sys::RunSignalHandlers() (/home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build/bin/../lib/libLLVMSupport.so.21.0git+0x1cdf40)
 #2 0x0000fc3b9a5ce0a0 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #3 0x0000fc3b9a8a88f8 (linux-vdso.so.1+0x8f8)
 #4 0x0000fc3b99ecf1f0 __pthread_kill_implementation ./nptl/./nptl/pthread_kill.c:44:76
 #5 0x0000fc3b99e8a67c gsignal ./signal/../sysdeps/posix/raise.c:27:6
 #6 0x0000fc3b99e77130 abort ./stdlib/./stdlib/abort.c:81:7
 #7 0x0000fc3b99e83fd4 __assert_fail_base ./assert/./assert/assert.c:91:7
 #8 0x0000fc3b99e8404c (/lib/aarch64-linux-gnu/libc.so.6+0x3404c)
 #9 0x0000c5ee2c5b1534 (anonymous namespace)::DecoderTable::patchNumToSkip(unsigned long, unsigned int) DecoderEmitter.cpp:0:0
#10 0x0000c5ee2c5bbcf0 (anonymous namespace)::FilterChooser::emitTableEntries((anonymous namespace)::DecoderTableInfo&) const DecoderEmitter.cpp:0:0
#11 0x0000c5ee2c5bb6a0 (anonymous namespace)::FilterChooser::emitTableEntries((anonymous namespace)::DecoderTableInfo&) const DecoderEmitter.cpp:0:0
#12 0x0000c5ee2c5bca58 llvm::EmitDecoder(llvm::RecordKeeper const&, llvm::raw_ostream&, llvm::StringRef) (/home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build/bin/llvm-tblgen+0x1bca58)
#13 0x0000c5ee2c5d0664 emitDisassembler(llvm::RecordKeeper const&, llvm::raw_ostream&) DisassemblerEmitter.cpp:0:0
#14 0x0000fc3b9a813fd8 llvm::TableGen::Emitter::ApplyCallback(llvm::RecordKeeper const&, llvm::raw_ostream&) (/home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build/bin/../lib/libLLVMTableGen.so.21.0git+0x53fd8)
#15 0x0000fc3b9a7de0d8 llvm::TableGenMain(char const*, std::function<bool (llvm::raw_ostream&, llvm::RecordKeeper const&)>) (/home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build/bin/../lib/libLLVMTableGen.so.21.0git+0x1e0d8)
#16 0x0000c5ee2c446c64 tblgen_main(int, char**) (/home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build/bin/llvm-tblgen+0x46c64)
#17 0x0000fc3b99e773fc __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3
#18 0x0000fc3b99e774cc call_init ./csu/../csu/libc-start.c:128:20
#19 0x0000fc3b99e774cc __libc_start_main ./csu/../csu/libc-start.c:379:5
#20 0x0000c5ee2c417230 _start (/home/tcwg-buildbot/worker/flang-aarch64-latest-gcc/build/bin/llvm-tblgen+0x17230)
Aborted
149.710 [5460/12/1923] Building AArch64GenRegisterBank.inc...
149.788 [5460/11/1924] Building AArch64GenAsmWriter.inc...
150.118 [5460/10/1925] Building AArch64GenAsmMatcher.inc...
150.187 [5460/9/1926] Building AArch64GenRegisterInfo.inc...
150.884 [5460/8/1927] Building AArch64GenFastISel.inc...
151.638 [5460/7/1928] Building AArch64GenGlobalISel.inc...
153.132 [5460/6/1929] Building CXX object lib/Object/CMakeFiles/LLVMObject.dir/IRSymtab.cpp.o
154.249 [5460/5/1930] Building AArch64GenDAGISel.inc...
160.925 [5460/4/1931] Building CXX object lib/MC/MCParser/CMakeFiles/LLVMMCParser.dir/AsmParser.cpp.o
162.517 [5460/3/1932] Building AArch64GenInstrInfo.inc...
164.111 [5460/2/1933] Building AArch64GenSubtargetInfo.inc...

```

</details>

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