[LLVMdev] bytecode reader assertion failure

[Ryan M. Lefever]

I have further diagnosed the problem and submitted a bug report, which 
can be found at http://llvm.org/bugs/show_bug.cgi?id=1223  My diagnosis 
is included in the bug report, if you're interested.

Thanks,
Ryan


Ryan M. Lefever wrote:
> I am still diagnosing the cause of the assertion failure and will submit 
> a bug when I better understand the problem.
> 
> Reid Spencer wrote:
> 
>>Ryan,
>>
>>This looks like a bug. Could you file it, please?
>>
>>Reid.
>>
>>On Thu, 2007-02-22 at 19:47 -0600, Ryan M. Lefever wrote:
>>
>>
>>>I have a compiler transform that I have been working on that produces 
>>>bytecode that passes the verifier.  However, when I try to read that 
>>>bytecode back in, I get the assertion failure below.
>>>
>>>llvm::BytecodeReader::ParseConstantPoolValue(unsigned int):
>>>Assertion `(!isa<Constant>(Result) || 
>>>!cast<Constant>(Result)->isNullValue()) || !hasImplicitNull(TypeID) && 
>>>"Cannot read null values from bytecode!"' failed.
>>>
>>>So, I ran gdb on opt.  I was able to get the following information from opt:
>>>
>>>(gdb) print Result
>>>$7 = (class llvm::Constant *) 0x96ad9d0
>>>(gdb) call Result->dump()
>>> [41 x sbyte *] zeroinitializer
>>>(gdb) print hasImplicitNull(TypeID)
>>>$5 = true
>>>
>>>Does anyone have any insight into what the problem is or how to go about 
>>> fixing it?  It seems diffcult to get context for what is going on, 
>>>since the bytecode has not yet been fully read.  Any help would be 
>>>greatly appreciated!
>>>
>>>The full output of the assertion failure is given below:
>>>
>>>opt -simplifycfg -deadargelim -globaldce -verify -f -o /dev/null tmp.bc
>>>opt: Reader.cpp:1978: llvm::Value* 
>>>llvm::BytecodeReader::ParseConstantPoolValue(unsigned int): Assertion 
>>>`(!isa<Constant>(Result) || !cast<Constant>(Result)->isNullValue()) || 
>>>!hasImplicitNull(TypeID) && "Cannot read null values from bytecode!"' 
>>>failed.
>>>opt((anonymous namespace)::PrintStackTrace()+0x1a)[0x8645bae]
>>>opt((anonymous namespace)::SignalHandler(int)+0x112)[0x8645e74]
>>>[0xb87420]
>>>/lib/libc.so.6(abort+0x101)[0x4cab64f1]
>>>/lib/libc.so.6(__assert_fail+0xfd)[0x4caae859]
>>>opt(llvm::BytecodeReader::ParseConstantPoolValue(unsigned 
>>>int)+0x1b31)[0x856e825]
>>>opt(llvm::BytecodeReader::ParseConstantPool(std::vector<llvm::BytecodeReader::ValueList*, 
>>>std::allocator<llvm::BytecodeReader::ValueList*> >&, 
>>>std::vector<llvm::PATypeHolder, std::allocator<llvm::PATypeHolder> >&, 
>>>bool)+0x147)[0x856e985]
>>>opt(llvm::BytecodeReader::ParseModule()+0x188)[0x856edfe]
>>>opt(llvm::BytecodeReader::ParseBytecode(unsigned char const*, unsigned 
>>>int, std::basic_string<char, std::char_traits<char>, 
>>>std::allocator<char> > const&, std::basic_string<char, 
>>>std::char_traits<char>, std::allocator<char> >*)+0x539)[0x856f6c1]
>>>opt((anonymous 
>>>namespace)::BytecodeFileReader::read(std::basic_string<char, 
>>>std::char_traits<char>, std::allocator<char> >*)+0xeb)[0x855b569]
>>>opt(llvm::getBytecodeModuleProvider(std::basic_string<char, 
>>>std::char_traits<char>, std::allocator<char> > const&, 
>>>std::basic_string<char, std::char_traits<char>, std::allocator<char> >*, 
>>>llvm::BytecodeHandler*)+0x93)[0x855b60b]
>>>opt(llvm::ParseBytecodeFile(std::basic_string<char, 
>>>std::char_traits<char>, std::allocator<char> > const&, 
>>>std::basic_string<char, std::char_traits<char>, std::allocator<char> 
>>>
>>>>*)+0x20)[0x855b88e]
>>>
>>>opt(main+0x7e)[0x8378c90]
>>>/lib/libc.so.6(__libc_start_main+0xdc)[0x4caa24e4]
>>>opt(__gxx_personality_v0+0x149)[0x836bac1]
>>>
>>>
>>>Regards,
>>>Ryan
>>>_______________________________________________
>>>LLVM Developers mailing list
>>>LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>>>http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
>>
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> 
> 

-- 
Ryan M. Lefever  [http://www.ews.uiuc.edu/~lefever]