[cfe-dev] Expr::isIntegerConstantExpr() gives bogus results with sizeof()

[Ted Kremenek]

That worked for me over the weekend, but now there are other build  
issues.  Building a fresh checkout of LLVM now fails on Leopard:

llvm[2]: Linking Debug executable llvm-as
llvm[2]: Compiling GraphPrinters.cpp for Debug build
llvm[2]: Linking Debug executable llvm-dis
llvm[2]: Compiling PrintSCC.cpp for Debug build
llvm[2]: Compiling UpgradeLexer.cpp for Debug build
Undefined symbols:
   "llvm::PointerType::get(llvm::Type const*)", referenced from:
       llvm::BitcodeReader::ParseTypeTable()      in  
libLLVMBitReader.a(BitcodeReader.o)
       llvm::BitcodeReader::ParseFunctionBody(llvm::Function*)    in  
libLLVMBitReader.a(BitcodeReader.o)
        
llvm 
::GetElementPtrInst::GetElementPtrInst<llvm::Value**>(llvm::Value*,  
llvm::Value**, llvm::Value**, std::basic_string<char,  
std::char_traits<char>, std::allocator<char> > const&,  
llvm::Instruction*)in libLLVMBitReader.a(BitcodeReader.o)
   "llvm::Pass::getPassName() const", referenced from:
       vtable for llvm::PrintModulePassin llvm-dis.o
   "llvm::FreeInst::FreeInst(llvm::Value*, llvm::Instruction*)",  
referenced from:
       llvm::BitcodeReader::ParseFunctionBody(llvm::Function*)    in  
libLLVMBitReader.a(BitcodeReader.o)
   "vtable for llvm::InvokeInst", referenced from:
...

On Nov 26, 2007, at 9:43 AM, Devang Patel wrote:

> Remove /Volumes/sandbox/llvm/lib/AsmParser/Lexer.cpp file and redo  
> make.
>
> -
> Devang
>
> On Nov 26, 2007, at 9:40 AM, Fariborz Jahanian wrote:
>
>> I am not sure this is the right forum for reporting LLVM build
>> problems. But here it is. After a recent update, I get this build
>> error building llvm:
>>
>> llvm[2]: Compiling Lexer.cpp for Debug build
>> /Volumes/sandbox/llvm/lib/AsmParser/Lexer.l: In function ‘int
>> llvmAsmlex()’:
>> /Volumes/sandbox/llvm/lib/AsmParser/Lexer.l:278: error: ‘PURE’ was
>> not declared in this scope
>> /Volumes/sandbox/llvm/lib/AsmParser/Lexer.l:279: error: ‘CONST’ was
>> not declared in this scope
>> Lexer.cpp: In function ‘int yy_get_next_buffer()’:
>> Lexer.cpp:2543: warning: comparison between signed and unsigned
>> integer expressions
>> make[2]: *** [/Volumes/sandbox/llvm/lib/AsmParser/Debug/Lexer.o]
>> Error 1
>> make[1]: *** [AsmParser/.makeall] Error 2
>> make: *** [all] Error 1
>>
>>
>> - Fariborz
>>
>> On Nov 26, 2007, at 8:40 AM, Ted Kremenek wrote:
>>
>>>
>>> On Nov 25, 2007, at 10:06 PM, Chris Lattner wrote:
>>>
>>>>>>> So it seems that sizeof() is being computed in bits, but then  
>>>>>>> the
>>>>>>> operations aren't consistent. (in fact it should be computed in
>>>>>>> bytes,
>>>>>>> as that's the value of that operator in C/C++)
>>>>>>
>>>>>> Yep, you're right, applied, thanks!
>>>>>>
>>>>>> -Chris
>>>>>
>>>>> Should the fix instead go in the body of getTypeSize() instead of
>>>>> within isConstantExpr()?  Should getTypeSize() ever return the
>>>>> number of bits instead of the number of bytes?  Does this have
>>>>> something to do with bitfields?
>>>>
>>>> This is the right solution.  We want getTypeSize to be unambiguous
>>>> as to units, and bits are the most constant thing there are.
>>>> Various strange things like bitfields, non-8-bit-bytes, and
>>>> datatypes that are not even multiples of byte sizes all conspire to
>>>> wanting to have a simple and unambiguous unit to represent things
>>>> in, bits is the right way to go.
>>>
>>> Okay.  Seems like a valid reason to me.
>>>
>>>> sizeof, on the other hand, is determined in units of sizeof(char).
>>>> To be fully general, it shouldn't divide by 8, it should divide by
>>>> TargetInfo.getCharSize().
>>>
>>> Should we go ahead and do this?
>>>
>>> Nuno:  Thanks again for finding this bug.
>>> _______________________________________________
>>> cfe-dev mailing list
>>> cfe-dev at cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev
>>
>
> -
> Devang
>
>
>
>
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