[IMPALA-6435] Codegen crash when UNIONing CHAR(n) literals

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: Impala 2.8.0, Impala 2.9.0, Impala 2.10.0, Impala 2.11.0
• Fix Version/s: Impala 2.12.0
• Component/s: Backend
• Labels: codegen crash
• Target Version: Impala 2.12.0
• Epic Color: ghx-label-8
• Assignee: Anuj Phadke
• Reporter: Balazs Jeszenszky
• Created: 23/Jan/18 10:45
• Updated: 30/Aug/18 18:20
• Resolved: 24/Jan/18 07:36

Description

A simple repro:

create table test (c1 int);
select cast ('a' as char(30)) as m from test
union all
select cast ('a' as char(30)) as m from test
;

Stack trace:

#0  0x00007fb0085275e5 in raise () from /lib64/libc.so.6
#1  0x00007fb008528dc5 in abort () from /lib64/libc.so.6
#2  0x00007fb00a663a55 in os::abort(bool) () from /usr/java/jdk1.7.0_67-cloudera/jre/lib/amd64/server/libjvm.so
#3  0x00007fb00a7e3f87 in VMError::report_and_die() ()
   from /usr/java/jdk1.7.0_67-cloudera/jre/lib/amd64/server/libjvm.so
#4  0x00007fb00a66896f in JVM_handle_linux_signal ()
   from /usr/java/jdk1.7.0_67-cloudera/jre/lib/amd64/server/libjvm.so
#5  <signal handler called>
#6  0x0000000001a9042d in llvm::FunctionType::get(llvm::Type*, llvm::ArrayRef<llvm::Type*>, bool) ()
#7  0x0000000000c2b62f in impala::LlvmCodeGen::FnPrototype::GeneratePrototype(impala::LlvmBuilder*, llvm::Value**, bool) ()
#8  0x0000000000846617 in impala::Expr::CreateIrFunctionPrototype(impala::LlvmCodeGen*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, llvm::Value* (*) [2]) ()
#9  0x000000000085960c in impala::Literal::GetCodegendComputeFn(impala::LlvmCodeGen*, llvm::Function**) ()
#10 0x0000000000a78467 in impala::Tuple::CodegenMaterializeExprs(impala::LlvmCodeGen*, bool, impala::TupleDescriptor const&, std::vector<impala::ExprContext*, std::allocator<impala::ExprContext*> > const&, bool, llvm::Function**) ()
#11 0x0000000000d11df8 in impala::UnionNode::Codegen(impala::RuntimeState*) ()
#12 0x0000000000a7dd4e in impala::FragmentInstanceState::Prepare() ()
#13 0x0000000000a7e311 in impala::FragmentInstanceState::Exec() ()
#14 0x0000000000a6a2f6 in impala::QueryState::ExecFInstance(impala::FragmentInstanceState*) ()

A debug build will fail a bit differently, hitting the DCHECK in codegen-anyval.cc.

Issue Links

• is broken by: IMPALA-1788 Consider replacing constant exprs with literal equivalents
• is related to: IMPALA-7032 Codegen crash when UNIONing NULL and CHAR(N)