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

Wed Apr 16 13:24:36 PDT 2025

llvm-ci wrote:

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

Full details are available at: https://lab.llvm.org/buildbot/#/builders/50/builds/12867

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
29.873 [3370/37/3444] Building CXX object tools/clang/lib/Parse/CMakeFiles/obj.clangParse.dir/ParseOpenACC.cpp.o
29.874 [3370/36/3445] Building CXX object tools/clang/lib/Parse/CMakeFiles/obj.clangParse.dir/ParseDecl.cpp.o
29.875 [3370/35/3446] Building CXX object tools/clang/lib/Parse/CMakeFiles/obj.clangParse.dir/ParseTemplate.cpp.o
29.886 [3370/34/3447] Building CXX object tools/clang/lib/Parse/CMakeFiles/obj.clangParse.dir/ParseStmt.cpp.o
29.890 [3370/33/3448] Building VCIXOps.cpp.inc...
29.890 [3370/32/3449] Building VCIXOpsDialect.cpp.inc...
29.891 [3370/31/3450] Building VCIXOps.h.inc...
29.891 [3370/30/3451] Building VCIXOpsDialect.h.inc...
29.891 [3370/29/3452] Building VCIXOpsTypes.cpp.inc...
29.893 [3369/29/3453] Building AArch64GenDisassemblerTables.inc...
FAILED: lib/Target/AArch64/AArch64GenDisassemblerTables.inc /home/tcwg-buildbot/worker/flang-aarch64-dylib/build/lib/Target/AArch64/AArch64GenDisassemblerTables.inc 
cd /home/tcwg-buildbot/worker/flang-aarch64-dylib/build && /home/tcwg-buildbot/worker/flang-aarch64-dylib/build/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/llvm/lib/Target/AArch64 -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/include -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/llvm/include -I /home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/llvm/lib/Target /home/tcwg-buildbot/worker/flang-aarch64-dylib/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-dylib/build/bin/llvm-tblgen -gen-disassembler --num-to-skip-size=3 -I /home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/llvm/lib/Target/AArch64 -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/include -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/llvm/include -I /home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/llvm/lib/Target /home/tcwg-buildbot/worker/flang-aarch64-dylib/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 0x0000bf0b6f78ce94 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/bin/llvm-tblgen+0x32ce94)
 #1 0x0000bf0b6f78ae94 llvm::sys::RunSignalHandlers() (/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/bin/llvm-tblgen+0x32ae94)
 #2 0x0000bf0b6f78d59c SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #3 0x0000fc9edae088f8 (linux-vdso.so.1+0x8f8)
 #4 0x0000fc9eda8cf1f0 __pthread_kill_implementation ./nptl/./nptl/pthread_kill.c:44:76
 #5 0x0000fc9eda88a67c gsignal ./signal/../sysdeps/posix/raise.c:27:6
 #6 0x0000fc9eda877130 abort ./stdlib/./stdlib/abort.c:81:7
 #7 0x0000fc9eda883fd4 __assert_fail_base ./assert/./assert/assert.c:91:7
 #8 0x0000fc9eda88404c (/lib/aarch64-linux-gnu/libc.so.6+0x3404c)
 #9 0x0000bf0b6f6287fc (anonymous namespace)::FilterChooser::emitTableEntries((anonymous namespace)::DecoderTableInfo&) const DecoderEmitter.cpp:0:0
#10 0x0000bf0b6f628668 (anonymous namespace)::FilterChooser::emitTableEntries((anonymous namespace)::DecoderTableInfo&) const DecoderEmitter.cpp:0:0
#11 0x0000bf0b6f62491c (anonymous namespace)::DecoderEmitter::run(llvm::raw_ostream&) DecoderEmitter.cpp:0:0
#12 0x0000bf0b6f620498 llvm::EmitDecoder(llvm::RecordKeeper const&, llvm::raw_ostream&, llvm::StringRef) (/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/bin/llvm-tblgen+0x1c0498)
#13 0x0000bf0b6f63f724 emitDisassembler(llvm::RecordKeeper const&, llvm::raw_ostream&) DisassemblerEmitter.cpp:0:0
#14 0x0000bf0b6f7c0954 llvm::TableGen::Emitter::ApplyCallback(llvm::RecordKeeper const&, llvm::raw_ostream&) (/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/bin/llvm-tblgen+0x360954)
#15 0x0000bf0b6f79bd74 llvm::TableGenMain(char const*, std::function<bool (llvm::raw_ostream&, llvm::RecordKeeper const&)>) (/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/bin/llvm-tblgen+0x33bd74)
#16 0x0000bf0b6f4b719c tblgen_main(int, char**) (/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/bin/llvm-tblgen+0x5719c)
#17 0x0000fc9eda8773fc __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3
#18 0x0000fc9eda8774cc call_init ./csu/../csu/libc-start.c:128:20
#19 0x0000fc9eda8774cc __libc_start_main ./csu/../csu/libc-start.c:379:5
#20 0x0000bf0b6f480d30 _start (/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/bin/llvm-tblgen+0x20d30)
Aborted
29.893 [3369/28/3454] Building VCIXOpsTypes.h.inc...
29.894 [3369/27/3455] Building VCIXConversions.inc...
29.894 [3369/26/3456] Building VCIXOpsAttributes.cpp.inc...
29.896 [3369/25/3457] Building VCIXOpsAttributes.h.inc...
29.904 [3369/24/3458] Building BuiltinDialectBytecode.cpp.inc...
29.915 [3369/23/3459] Building CXX object tools/clang/lib/Parse/CMakeFiles/obj.clangParse.dir/ParseStmtAsm.cpp.o
29.940 [3369/22/3460] Building AArch64GenAsmWriter1.inc...
29.943 [3369/21/3461] Building CXX object tools/clang/lib/CodeGen/CMakeFiles/obj.clangCodeGen.dir/MacroPPCallbacks.cpp.o
29.960 [3369/20/3462] Building CXX object tools/clang/lib/Basic/CMakeFiles/obj.clangBasic.dir/Warnings.cpp.o
29.973 [3369/19/3463] Building CXX object tools/clang/lib/CodeGen/CMakeFiles/obj.clangCodeGen.dir/LinkInModulesPass.cpp.o
30.031 [3369/18/3464] Building CXX object tools/clang/lib/CodeGen/CMakeFiles/obj.clangCodeGen.dir/BackendUtil.cpp.o

```

</details>

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