llvm dev - Nov 2010 - [LLVMdev] llvm-gcc not compatible with gcc on a small case?

I found a case which gcc can compile while llvm-gcc can not. I'm using the
gcc4.1 and  the most recent llvm-gcc.

Here is the case:

template <int N>
class T {
public:
  int V;
};

T<4> test(T<4> a[4][8]) {
  return a[3][3];
}



llvm-gcc dumped:

fail.cpp: In function \u2018T<4> test(T<4> (*)[8])\u2019:
fail.cpp:7: error: invalid use of incomplete type \u2018class T<4>\u2019
fail.cpp:2: error: declaration of \u2018class T<4>\u2019

Guys, any idea for this issue?
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Whoops, forgot to CC: the list.
>
>----- Forwarded Message ----
>From: Samuel Crow <samuraileumas at yahoo.com>
>To: Sheng Zhou <zhousheng00 at gmail.com>
>Sent: Tue, November 9, 2010 9:26:51 PM
>Subject: Re: [LLVMdev]  llvm-gcc not compatible with gcc on a small case?
>
>
>Hi Sheng Zhou,
>
>
>It shouldn't compile.  You have the method declared inside the templated
class
>thus indicating infinite recursion.  It should be outside the template
shouldn't
>it?  What was the command line you used to compile it under both GCC and 
>LLVM-GCC?
>
>
>--Sam Crow
>
>>
>>From: Sheng Zhou <zhousheng00 at gmail.com>
>>To: llvmdev at cs.uiuc.edu
>>Sent: Tue, November 9, 2010 9:07:46 PM
>>Subject: [LLVMdev]  llvm-gcc not compatible with gcc on a small case?
>>
>>I found a case which gcc can compile while llvm-gcc can not. I'm
using the
>>gcc4.1 and  the most recent llvm-gcc.
>>
>>Here is the case:
>>
>>template <int N>
>>class T { 
>>public:
>>  int V;
>>};
>>
>>T<4> test(T<4> a[4][8]) {
>>  return a[3][3];
>>}
>>
>>
>>
>>llvm-gcc dumped:
>>
>>fail.cpp: In function \u2018T<4> test(T<4> (*)[8])\u2019:
>>fail.cpp:7: error: invalid use of incomplete type \u2018class
T<4>\u2019
>>fail.cpp:2: error: declaration of \u2018class T<4>\u2019
>>
>>Guys, any idea for this issue?
>>
>

      
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On 11/09/10 22:27, Samuel Crow wrote:
>> It shouldn't compile.  You have the method declared inside the
templated class
>> thus indicating infinite recursion.
No, the method is not in the class.  It is a function that returns a 
T<4> and takes (approximately) a reference to a multidimensional array 
of T<4>s.  In fact it compiles fine for me, with no warnings, under both
g++ -Wall -c thing.cpp  # version 4.5.1
clang++ -Wall -c thing.cpp  # version 2.8

Perhaps gcc-4.2 (the base GCC version of llvm-gcc, unless you have a 
really old one, check llvm-gcc --version ?) gets confused about that 
code, or such?

-Isaac