https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67650
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |link-failure
--- Comment #29 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Vincent from comment #27)
> Sorry for the silly check, are you sure you are trying with -O3 or
> -fdevirtualize -O2?
I've tried both. I'm using x86_64-pc-linux-gnu though.
> You can try this with 8.1:
>
> void *v;
>
> template <typename T>
> struct LK: public BLKC
> {
> void rb(){((T*)v)->ax();}
> static T* st;
> };
>
> As a replacement to the call to null, and the missing definition problem is
> reported.
OK now I can reproduce it with trunk.
(In reply to Vincent from comment #28)
> Other silly check, did you try with my code or your reduced code ?
Yours.
Here's the reduced form that gives a link-error with trunk:
#include <string>
template <typename T>
struct RE
{
virtual void rp()=0;
void ax(){rp();}
};
struct EN : RE<int>
{
EN(::std::string = ""){}
void rp(){}
};
template <typename OC>
struct AN : RE<OC>
{
void rp(){}
};
template <typename T>
struct LK
{
T* p = nullptr;
virtual void rb(){p->ax();}
};
template <const char* K>
struct LR
{
virtual ~LR(){}
struct LLC { virtual ~LLC(){} };
LK<AN<LLC>> l;
};
constexpr char ET[]="";
struct I : EN
{
LR<ET> _e;
};
int main(){new I();}
$ ~/gcc/8.1.0/bin/g++ -Wall -O1 -fdevirtualize main.cc
main.cc:19:8: warning: ‘void AN<OC>::rp() [with OC = LR<(& ET)>::LLC]’ used but
never defined
void rp(){}
^~
/tmp/cc4IHAPf.o: In function `LK<AN<LR<&ET>::LLC> >::rb()':
main.cc:(.text+0x37): undefined reference to `AN<LR<&ET>::LLC>::rp()'
collect2: error: ld returned 1 exit status
