Re: c++/8660: template overloading ICE in tsubst_expr, at cp/pt.c:7644

Re: c++/8660: template overloading ICE in tsubst_expr, at cp/pt.c:7644

[bangerth]

Synopsis: template overloading ICE in tsubst_expr, at cp/pt.c:7644

State-Changed-From-To: open->analyzed
State-Changed-By: bangerth
State-Changed-When: Wed Nov 20 11:05:57 2002
State-Changed-Why:
    Confirmed. At least one case has been fixed on mainline
    in the meantime (but is still present in 3.2.1), namely the
    last one you mention (with parentheses, declarations swapped):
    struct BadgerBuf
    {
        template<class B>
        void ReadPod();
        void ReadPod();
    };
    
    void BadgerBuf::ReadPod ()
    { (ReadPod<int>) (); }
    
    However, the other ICEs still exist.
    
    I can reproduce all these ICEs with 2.95, so it is not a
    regression, although I would love to see this fixed soon
    anyway since it seems like a not so uncommon idiom.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8660

Re: c++/8660: template overloading ICE in tsubst_expr, at cp/pt.c:7644

[Volker Reichelt]

The following reply was made to PR c++/8660; it has been noted by GNATS.

From: Volker Reichelt <reichelt@igpm.rwth-aachen.de>
To: gcc-gnats@gcc.gnu.org, martin.dorey@bluearc.com, gcc-bugs@gcc.gnu.org
Cc:  
Subject: Re: c++/8660: template overloading ICE in tsubst_expr, at cp/pt.c:7644
Date: Wed, 22 Jan 2003 12:08:47 +0100

 Two bugs (the one with the parentheses, and the one with the additional
 template) have been fixed in 3.3 branch and mainline.
 
 That leaves us with the first ICE. This, however is a regression, since
 gcc 3.0.x did compile the code (gcc issued an ICE, though).
 
 Regards,
 Volker
 
 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8660
 
 

c++/8660: template overloading ICE in tsubst_expr, at cp/pt.c:7644

[martin.dorey]

>Number:         8660
>Category:       c++
>Synopsis:       template overloading ICE in tsubst_expr, at cp/pt.c:7644
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Nov 20 10:46:03 PST 2002
>Closed-Date:
>Last-Modified:
>Originator:     Martin Dorey
>Release:        GNU C++ version 3.2.1 20021111 (Debian prerelease) (i386-linux)
>Organization:
>Environment:
Linux trevithick 2.4.16 #2 Mon Dec 10 15:54:50 GMT 2001 i686 unknown unknown GNU/Linux
>Description:
trevithick:~/stingray/test/data_structures$ gcc-3.2 -v -c -W -Wall -pedantic --save-temps bug0.cpp 
Reading specs from /usr/lib/gcc-lib/i386-linux/3.2.1/specs
Configured with: /home/packages/gcc/3.2/gcc-3.2-3.2.1ds5/src/configure -v --enable-languages=c,c++,java,f77,proto,objc,ada --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-gxx-include-dir=/usr/include/c++/3.2 --enable-shared --with-system-zlib --enable-nls --without-included-gettext --enable-__cxa_atexit --enable-clocale=gnu --enable-java-gc=boehm --enable-objc-gc i386-linux
Thread model: posix
gcc version 3.2.1 20021111 (Debian prerelease)
 /usr/lib/gcc-lib/i386-linux/3.2.1/cpp0 -lang-c++ -D__GNUG__=3 -D__DEPRECATED -D__EXCEPTIONS -v -D__GNUC__=3 -D__GNUC_MINOR__=2 -D__GNUC_PATCHLEVEL__=1 -D__GXX_ABI_VERSION=102 -D__ELF__ -Dunix -D__gnu_linux__ -Dlinux -D__ELF__ -D__unix__ -D__gnu_linux__ -D__linux__ -D__unix -D__linux -Asystem=posix -D__NO_INLINE__ -D__STDC_HOSTED__=1 -D_GNU_SOURCE -Acpu=i386 -Amachine=i386 -Di386 -D__i386 -D__i386__ -D__tune_i386__ bug0.cpp -W -Wall -pedantic bug0.ii
GNU CPP version 3.2.1 20021111 (Debian prerelease) (cpplib) (i386 Linux/ELF)
ignoring nonexistent directory "/usr/i386-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c++/3.2
 /usr/include/c++/3.2/i386-linux
 /usr/include/c++/3.2/backward
 /usr/local/include
 /usr/lib/gcc-lib/i386-linux/3.2.1/include
 /usr/include
End of search list.
 /usr/lib/gcc-lib/i386-linux/3.2.1/cc1plus -fpreprocessed bug0.ii -quiet -dumpbase bug0.cpp -W -Wall -pedantic -version -o bug0.s
GNU CPP version 3.2.1 20021111 (Debian prerelease) (cpplib) (i386 Linux/ELF)
GNU C++ version 3.2.1 20021111 (Debian prerelease) (i386-linux)
        compiled by GNU C version 3.2.1 20021111 (Debian prerelease).
bug0.cpp: In member function `void BadgerBuf::ReadPod() [with B = int]':
bug0.cpp:10:   instantiated from here
bug0.cpp:10: Internal compiler error in tsubst_expr, at cp/pt.c:7644
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://www.gnu.org/software/gcc/bugs.html> for instructions.
>How-To-Repeat:
Source is:

struct BadgerBuf
{
  void ReadPod();
  template<class B>
  void ReadPod();
};

void BadgerBuf::ReadPod ()
  { ReadPod<int> (); }

Adding this-> to the call to ReadPod<int> doesn't change the behaviour.  Nor does "this->template ".  Putting brackets round the (ReadPod<int>) part causes a different error:

bug0.cpp: In member function `void BadgerBuf::ReadPod()':
bug0.cpp:10: internal error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://www.gnu.org/software/gcc/bugs.html> for instructions.

Swapping the order of the declarations avoids the problem.  Unless you've left the brackets around (ReadPod<int>) in which case it still segfaults.

If you leave the declarations swapped but add another template between the class definition and the function definition, like so:

struct BadgerBuf
{
  template<class B>
  void ReadPod();
  void ReadPod();
};

template <class T>
struct Predicate 
  {};

void BadgerBuf::ReadPod ()
  { ReadPod<int> (); }

Then you get different behaviour again:

bug0.cpp: In member function `void BadgerBuf::ReadPod()':
bug0.cpp:14: parse error before `>' token

Perhaps I should have submitted these as separate bugs - but I can always do that later if they turn out to be unrelated.
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: