firefox does not build on -current: clang++ core dumps

[Thomas Klausner <tk%giga.or.at@localhost>]

Hi!

I've tried multiple times in from-scratch bulk builds (i.e., no old
packages) on freshly updated NetBSD-current systems (currently
9.99.63/amd64), but I can't get firefox 76.0.1 to build.

I thought it might be because I have clang in base, so I finally
installed a NetBSD without llvm in base, but it still doesn't build.

I get three clang++ core dumps (repeatably):

# find work/ -name *.core
work/build/layout/style/clang++.core
work/build/layout/generic/clang++.core
work/build/layout/painting/clang++.core

They have the following backtrace:

Core was generated by `clang++'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x00007d69ff59008d in llvm::SmallVectorImpl<llvm::MachineInstr*>::operator= (this=0x7f7fff4ef2a0, RHS=...)
    at /scratch/lang/llvm/work/llvm-10.0.0.src/include/llvm/ADT/SmallVector.h:706
706     /scratch/lang/llvm/work/llvm-10.0.0.src/include/llvm/ADT/SmallVector.h: No such file or directory.
(gdb) bt
#0  0x00007d69ff59008d in llvm::SmallVectorImpl<llvm::MachineInstr*>::operator= (this=0x7f7fff4ef2a0, RHS=...)
    at /scratch/lang/llvm/work/llvm-10.0.0.src/include/llvm/ADT/SmallVector.h:706
#1  0x00007d6a018083a4 in llvm::SmallVector<llvm::MachineInstr*, 4u>::SmallVector (RHS=..., this=0x7f7fff4ef2a0)
    at /scratch/lang/llvm/work/llvm-10.0.0.src/include/llvm/ADT/SmallVector.h:68
#2  (anonymous namespace)::X86CallFrameOptimization::CallContext::CallContext (this=0x7f7fff4ef280)
    at /scratch/lang/llvm/work/llvm-10.0.0.src/lib/Target/X86/X86CallFrameOptimization.cpp:70
#3  (anonymous namespace)::X86CallFrameOptimization::isProfitable (this=0x7d69df7eec80, this=0x7d69df7eec80, CallSeqVector=..., MF=...)
    at /scratch/lang/llvm/work/llvm-10.0.0.src/lib/Target/X86/X86CallFrameOptimization.cpp:205
#4  (anonymous namespace)::X86CallFrameOptimization::runOnMachineFunction (this=<optimized out>, MF=...)
    at /scratch/lang/llvm/work/llvm-10.0.0.src/lib/Target/X86/X86CallFrameOptimization.cpp:265
#5  0x00007d69ff5c410e in llvm::MachineFunctionPass::runOnFunction (this=0x7d69df7eec80, F=...)
    at /scratch/lang/llvm/work/llvm-10.0.0.src/lib/CodeGen/MachineFunctionPass.cpp:73
#6  0x00007d69ff3a0d19 in llvm::FPPassManager::runOnFunction (this=this@entry=0x7d69e33be840, F=...)
    at /scratch/lang/llvm/work/llvm-10.0.0.src/lib/IR/LegacyPassManager.cpp:1481
#7  0x00007d69ff3a1452 in llvm::FPPassManager::runOnModule (this=0x7d69e33be840, M=...)
    at /scratch/lang/llvm/work/llvm-10.0.0.src/lib/IR/LegacyPassManager.cpp:1517
#8  0x00007d69ff3a17cd in (anonymous namespace)::MPPassManager::runOnModule (M=..., this=0x7d69f80bee00)
    at /scratch/lang/llvm/work/llvm-10.0.0.src/lib/IR/LegacyPassManager.cpp:1582
#9  llvm::legacy::PassManagerImpl::run (this=0x7d69f4b9be00, M=...)
    at /scratch/lang/llvm/work/llvm-10.0.0.src/lib/IR/LegacyPassManager.cpp:1694
#10 0x00007d69ff3a1a5d in llvm::legacy::PassManager::run (this=this@entry=0x7f7fff8e6700, M=...)
    at /scratch/lang/llvm/work/llvm-10.0.0.src/lib/IR/LegacyPassManager.cpp:1725
#11 0x00007d6a050b05da in (anonymous namespace)::EmitAssemblyHelper::EmitAssemblyWithNewPassManager (this=<optimized out>, 
    Action=<optimized out>, OS=...) at /scratch/lang/clang/work/clang-10.0.0.src/lib/CodeGen/BackendUtil.cpp:1329
#12 0x00007d6a050b3f88 in clang::EmitBackendOutput (Diags=..., HeaderOpts=..., CGOpts=..., TOpts=..., LOpts=..., TDesc=..., M=0x7d6a0671b600, 
    Action=Action@entry=clang::Backend_EmitObj, OS=...) at /usr/include/g++/bits/unique_ptr.h:366
#13 0x00007d6a053a6f39 in clang::BackendConsumer::HandleTranslationUnit (this=0x7d6a06753a80, C=...) at /usr/include/g++/bits/unique_ptr.h:345
#14 0x00007d6a0436f61a in clang::ParseAST (S=..., PrintStats=<optimized out>, SkipFunctionBodies=<optimized out>)
    at /scratch/lang/clang/work/.buildlink/include/llvm/ADT/StringRef.h:143
#15 0x00007d6a0589b14e in clang::FrontendAction::Execute (this=this@entry=0x7d6a06750540)
    at /scratch/lang/clang/work/clang-10.0.0.src/lib/Frontend/FrontendAction.cpp:936
#16 0x00007d6a05857109 in clang::CompilerInstance::ExecuteAction (this=this@entry=0x7d6a06753600, Act=...)
    at /scratch/lang/clang/work/clang-10.0.0.src/lib/Frontend/CompilerInstance.cpp:965
#17 0x00007d6a059215e5 in clang::ExecuteCompilerInvocation (Clang=Clang@entry=0x7d6a06753600)
    at /scratch/lang/clang/work/clang-10.0.0.src/lib/FrontendTool/ExecuteCompilerInvocation.cpp:290
#18 0x0000000000414f92 in cc1_main (Argv=..., Argv0=<optimized out>, 
    MainAddr=MainAddr@entry=0x4139c0 <GetExecutablePath[abi:cxx11](char const*, bool)>)
    at /scratch/lang/clang/work/clang-10.0.0.src/tools/driver/cc1_main.cpp:240
#19 0x0000000000412b95 in ExecuteCC1Tool (ArgV=...) at /scratch/lang/clang/work/.buildlink/include/llvm/ADT/ArrayRef.h:188
#20 0x00007d6a055a1612 in clang::driver::CC1Command::<lambda()>::operator() (__closure=0x7d6a06788400)
    at /scratch/lang/clang/work/clang-10.0.0.src/lib/Driver/Job.cpp:417
#21 llvm::function_ref<void()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef> >, std::__cxx11::
string*, bool*) const::<lambda()> >(intptr_t) (callable=callable@entry=140187725104624)
    at /scratch/lang/clang/work/.buildlink/include/llvm/ADT/STLExtras.h:108
#22 0x00007d69ff1ab733 in llvm::function_ref<void ()>::operator()() const (this=<synthetic pointer>, this=<synthetic pointer>)
    at /scratch/lang/llvm/work/llvm-10.0.0.src/include/llvm/ADT/STLExtras.h:124
#23 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (this=this@entry=0x7f7fff8e85d0, Fn=...)
    at /scratch/lang/llvm/work/llvm-10.0.0.src/lib/Support/CrashRecoveryContext.cpp:417
#24 0x00007d6a055a5923 in clang::driver::CC1Command::Execute (this=0x7d6a06735280, Redirects=..., ErrMsg=<optimized out>, 
    ExecutionFailed=<optimized out>) at /scratch/lang/clang/work/.buildlink/include/llvm/ADT/STLExtras.h:117
#25 0x00007d6a0557a48f in clang::driver::Compilation::ExecuteCommand (this=this@entry=0x7d6a066ab200, C=..., 
    FailingCommand=@0x7f7fff8e8750: 0x0) at /usr/include/g++/bits/stl_vector.h:1059
#26 0x00007d6a0557ad10 in clang::driver::Compilation::ExecuteJobs (this=this@entry=0x7d6a066ab200, Jobs=..., FailingCommands=...)
    at /scratch/lang/clang/work/clang-10.0.0.src/lib/Driver/Compilation.cpp:233
#27 0x00007d6a05589dd5 in clang::driver::Driver::ExecuteCompilation (this=this@entry=0x7f7fff8e8888, C=..., FailingCommands=...)
    at /scratch/lang/clang/work/clang-10.0.0.src/include/clang/Driver/Compilation.h:202
#28 0x00000000004113c9 in main (argc_=<optimized out>, argv_=<optimized out>)
    at /scratch/lang/clang/work/clang-10.0.0.src/tools/driver/driver.cpp:498

I last built firefox successfully on April 23 (version 75.0nb1).

Fixes very appreciated.
 Thomas