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

Wed Apr 16 15:53:00 PDT 2025

llvm-ci wrote:

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

Full details are available at: https://lab.llvm.org/buildbot/#/builders/20/builds/10916

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
260.442 [3717/1/3125] Building CXX object lib/Target/CMakeFiles/LLVMTarget.dir/Target.cpp.o
260.487 [3716/1/3126] Building CXX object lib/Target/CMakeFiles/LLVMTarget.dir/TargetLoweringObjectFile.cpp.o
260.535 [3715/1/3127] Building CXX object lib/Target/CMakeFiles/LLVMTarget.dir/TargetMachine.cpp.o
260.580 [3714/1/3128] Building CXX object lib/Target/CMakeFiles/LLVMTarget.dir/TargetMachineC.cpp.o
278.601 [3713/1/3129] Building AArch64GenAsmMatcher.inc...
291.890 [3712/1/3130] Building AArch64GenAsmWriter.inc...
304.154 [3711/1/3131] Building AArch64GenAsmWriter1.inc...
313.105 [3710/1/3132] Building AArch64GenCallingConv.inc...
359.555 [3709/1/3133] Building AArch64GenDAGISel.inc...
371.272 [3708/1/3134] Building AArch64GenDisassemblerTables.inc...
FAILED: lib/Target/AArch64/AArch64GenDisassemblerTables.inc /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/lib/Target/AArch64/AArch64GenDisassemblerTables.inc 
cd /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build && /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/llvm-project/llvm/lib/Target/AArch64 -I/home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/include -I/home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/llvm-project/llvm/include -I /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/llvm-project/llvm/lib/Target /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/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-debug-reverse-iteration/build/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/llvm-project/llvm/lib/Target/AArch64 -I/home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/include -I/home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/llvm-project/llvm/include -I /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/llvm-project/llvm/lib/Target /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/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 0x0000ad4c82b2e4f4 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/lib/Support/Unix/Signals.inc:804:11
 #1 0x0000ad4c82b2e9b4 PrintStackTraceSignalHandler(void*) /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/lib/Support/Unix/Signals.inc:880:1
 #2 0x0000ad4c82b2cc70 llvm::sys::RunSignalHandlers() /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/lib/Support/Signals.cpp:105:5
 #3 0x0000ad4c82b2f1ac SignalHandler(int, siginfo_t*, void*) /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/lib/Support/Unix/Signals.inc:418:7
 #4 0x0000fe4cf1c908f8 (linux-vdso.so.1+0x8f8)
 #5 0x0000fe4cf16cf1f0 __pthread_kill_implementation ./nptl/./nptl/pthread_kill.c:44:76
 #6 0x0000fe4cf168a67c gsignal ./signal/../sysdeps/posix/raise.c:27:6
 #7 0x0000fe4cf1677130 abort ./stdlib/./stdlib/abort.c:81:7
 #8 0x0000fe4cf1683fd4 __assert_fail_base ./assert/./assert/assert.c:91:7
 #9 0x0000fe4cf168404c (/lib/aarch64-linux-gnu/libc.so.6+0x3404c)
#10 0x0000ad4c8284ff68 (anonymous namespace)::DecoderTable::patchNumToSkip(unsigned long, unsigned int) /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/utils/TableGen/DecoderEmitter.cpp:152:22
#11 0x0000ad4c8283b378 resolveTableFixups((anonymous namespace)::DecoderTable&, std::vector<unsigned int, std::allocator<unsigned int> > const&, unsigned int) /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/utils/TableGen/DecoderEmitter.cpp:720:3
#12 0x0000ad4c8284d6c0 (anonymous namespace)::FilterChooser::emitSingletonTableEntry((anonymous namespace)::DecoderTableInfo&, (anonymous namespace)::Filter const&) const /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/utils/TableGen/DecoderEmitter.cpp:1475:3
#13 0x0000ad4c8283b1d0 (anonymous namespace)::FilterChooser::emitTableEntries((anonymous namespace)::DecoderTableInfo&) const /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/utils/TableGen/DecoderEmitter.cpp:1769:7
#14 0x0000ad4c8284d950 (anonymous namespace)::Filter::emitTableEntry((anonymous namespace)::DecoderTableInfo&) const /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/utils/TableGen/DecoderEmitter.cpp:779:9
#15 0x0000ad4c8283b1e0 (anonymous namespace)::FilterChooser::emitTableEntries((anonymous namespace)::DecoderTableInfo&) const /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/utils/TableGen/DecoderEmitter.cpp:1771:12
#16 0x0000ad4c82839460 (anonymous namespace)::DecoderEmitter::run(llvm::raw_ostream&) /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/utils/TableGen/DecoderEmitter.cpp:2549:8
#17 0x0000ad4c828389c0 llvm::EmitDecoder(llvm::RecordKeeper const&, llvm::raw_ostream&, llvm::StringRef) /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/utils/TableGen/DecoderEmitter.cpp:2584:42
#18 0x0000ad4c82882668 emitDisassembler(llvm::RecordKeeper const&, llvm::raw_ostream&) /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/utils/TableGen/DisassemblerEmitter.cpp:131:1
#19 0x0000ad4c8255534c 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&) /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/include/llvm/ADT/STLFunctionalExtras.h:46:5
#20 0x0000ad4c82b7ed84 llvm::function_ref<void (llvm::RecordKeeper const&, llvm::raw_ostream&)>::operator()(llvm::RecordKeeper const&, llvm::raw_ostream&) const /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/include/llvm/ADT/STLFunctionalExtras.h:69:5
#21 0x0000ad4c82b7e544 llvm::TableGen::Emitter::ApplyCallback(llvm::RecordKeeper const&, llvm::raw_ostream&) /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/lib/TableGen/TableGenBackend.cpp:68:3
#22 0x0000ad4c82b3c4f0 llvm::TableGenMain(char const*, std::function<bool (llvm::raw_ostream&, llvm::RecordKeeper const&)>) /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/lib/TableGen/Main.cpp:152:7
#23 0x0000ad4c825a7210 tblgen_main(int, char**) /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/utils/TableGen/Basic/TableGen.cpp:74:10
#24 0x0000ad4c8293cc28 main /home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/../llvm-project/llvm/utils/TableGen/llvm-tblgen.cpp:18:35
#25 0x0000fe4cf16773fc __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3
#26 0x0000fe4cf16774cc call_init ./csu/../csu/libc-start.c:128:20
#27 0x0000fe4cf16774cc __libc_start_main ./csu/../csu/libc-start.c:379:5
#28 0x0000ad4c82545d70 _start (/home/tcwg-buildbot/worker/flang-aarch64-debug-reverse-iteration/build/bin/llvm-tblgen+0x405d70)
Aborted
ninja: build stopped: subcommand failed.

```

</details>

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