| Summary: | [3.2/3.3/3.4 regression] Total confusion about template/friend/virtual/abstract | ||
|---|---|---|---|
| Product: | gcc | Reporter: | vil |
| Component: | c++ | Assignee: | Kriang Lerdsuwanakij <lerdsuwa> |
| Status: | RESOLVED FIXED | ||
| Severity: | critical | CC: | gcc-bugs, lerdsuwa, vil |
| Priority: | P1 | Keywords: | rejects-valid |
| Version: | 3.2 | ||
| Target Milestone: | --- | ||
| Host: | Target: | ||
| Build: | Known to work: | ||
| Known to fail: | Last reconfirmed: | ||
|
Description
vil
2003-02-06 21:26:00 UTC
Fix: please State-Changed-From-To: open->feedback
State-Changed-Why: For some reason, the testcase didn't make it into the
report. Can you try to send it to me so that I can attach
it to the report?
Thanks
Wolfgang
From: Victor Isaac Lesk <vil@rccp.tsukuba.ac.jp> To: <bangerth@dealii.org>, <gcc-bugs@gcc.gnu.org>, <gcc-prs@gcc.gnu.org>, <nobody@gcc.gnu.org>, <vil@rccp.tsukuba.ac.jp>, <gcc-gnats@gcc.gnu.org> Cc: Subject: Re: c++/9602: falsely concludes that function defined within class body is virtual and abstract, therefore compiler fails to allow class instantiation with pure virtual function error. Date: Fri, 7 Feb 2003 11:22:12 +0900 (JST) On 6 Feb 2003 bangerth@dealii.org wrote: > Synopsis: falsely concludes that function defined within class body is virtual and abstract, therefore compiler fails to allow class instantiation with pure virtual function error. > > State-Changed-From-To: open->feedback > State-Changed-By: bangerth > State-Changed-When: Thu Feb 6 23:23:46 2003 > State-Changed-Why: > For some reason, the testcase didn't make it into the > report. Can you try to send it to me so that I can attach > it to the report? > > Thanks > Wolfgang > > http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=9602 > Here it is: ////////////// #include<iostream> #include<stdio.h> using namespace std; template<typename t> class Pair { private: protected: public: t first; t second; t&last; Pair(); Pair(t,t); Pair(const string); void set_Pair(const t,const t); void set(const t,const t); void set_First(const t); void set_Second(const t); void set_Last(const t); t get_First(void)const; t get_Second(void)const; t get_Last(void)const; bool contains(const t)const; bool includes(const t)const; void display(void)const; void operator=(const Pair<t>); template<typename l>operator class Pair<l>(void)const; friend ostream&operator<<(ostream&a,const class Pair<t>&r) { return a<<r.first<<SPC<<r.second; } friend istream&operator>>(istream&a,class Pair<t>&r) { return a>>r.first>>r.second; } }; template<typename t> ostream& operator<<(ostream&,const Pair<t>&); template<typename t> istream& operator>>(istream&,Pair<t>&); template<typename t> Pair<t>:: Pair(): last(second) { } template<typename t> Pair<t>:: Pair(const string s): last(second) { } template<typename t> Pair<t>:: Pair(t a,t b): last(second) { set_Pair(a,b); } template<typename t> t Pair<t>:: get_First(void)const { return first; } template<typename t> t Pair<t>:: get_Second(void)const { return second; } template<typename t> t Pair<t>:: get_Last(void)const { return last; } template<typename t> void Pair<t>:: set(t l,t h) { first=l;second=h; } template<typename t> void Pair<t>:: operator=(const Pair<t> pair) { set_First(pair.first); set_Second(pair.second); } template<typename t> void Pair<t>:: set_Pair(t l,t h) { set(l,h); } template<typename t> void Pair<t>:: set_First(const t a) { first=a; } template<typename t> void Pair<t>:: set_Second(const t a) { second=a; } template<typename t> bool Pair<t>:: contains(const t a)const { return (a==first || a==second); } template<typename t> bool Pair<t>:: includes(const t a)const { return contains(a); } template<typename t> void Pair<t>:: display(void)const { cout<<LPR<<first<<COM<<second<<RPR; } template<typename t>template<typename l> Pair<t>:: operator Pair<l>(void)const { return Pair<l>(l(first),l(second)); } int main(const int,const char*const*const) { Pair<int> pair1; return 0; } State-Changed-From-To: feedback->analyzed
State-Changed-Why: Confirmed. This is a smaller testcase:
---------------------------
template <typename T> struct X {
void foo (X);
friend void bar () {}
};
template <typename T>
void X<T>::foo (X x) {}
template struct X<int>;
-----------------------------
There seems to be profound confusion within the compiler
about something, since it says
tmp/g> /home/bangerth/bin/gcc-3.2/bin/gcc -c x.cc
x.cc:7: cannot declare parameter `x' to be of type `X<T>'
x.cc:7: because the following virtual functions are abstract:
x.cc:3: void bar()
This is, of course, entirely bogus.
It worked with 3.0, but is broken with present 3.2.2, 3.3
and 3.4 branches, so it's a regression. The testcase is
so simple that I can't believe that this is something
that hasn't come up yet. Hopefully it's simple to fix.
From playing around, it seems to have to do with the fact
that the friend function is not only declared, but also
defined inside the class; it is instantiated at the place
of first use, which is where the error is displayed.
W.
Responsible-Changed-From-To: unassigned->lerdsuwa Responsible-Changed-Why: Figured out what's wrong. From: Kriang Lerdsuwanakij <lerdsuwa@users.sourceforge.net> To: gcc-gnats@gcc.gnu.org, vil@rccp.tsukuba.ac.jp, gcc-bugs@gcc.gnu.org, lerdsuwa@gcc.gnu.org, gcc-prs@gcc.gnu.org Cc: Subject: Re: c++/9602: [3.2/3.3/3.4 regression] Total confusion about template/friend/virtual/abstract Date: Fri, 21 Feb 2003 21:53:35 +0700 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=9602 Patch submitted: http://gcc.gnu.org/ml/gcc-patches/2003-02/msg01805.html From: lerdsuwa@gcc.gnu.org To: gcc-gnats@gcc.gnu.org Cc: Subject: c++/9602 Date: 24 Feb 2003 15:08:22 -0000 CVSROOT: /cvs/gcc Module name: gcc Branch: gcc-3_3-branch Changes by: lerdsuwa@gcc.gnu.org 2003-02-24 15:08:22 Modified files: gcc/cp : ChangeLog typeck2.c gcc/testsuite : ChangeLog Added files: gcc/testsuite/g++.dg/template: friend16.C Log message: PR c++/9602 * typeck2.c (abstract_virtuals_error): Don't check when we are processing a template. * g++.dg/template/friend16.C: New test. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=1.3076.2.45&r2=1.3076.2.46 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/typeck2.c.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=1.132&r2=1.132.4.1 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=1.2261.2.62&r2=1.2261.2.63 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/template/friend16.C.diff?cvsroot=gcc&only_with_tag=gcc-3_3-branch&r1=NONE&r2=1.1.2.1 From: lerdsuwa@gcc.gnu.org To: gcc-gnats@gcc.gnu.org Cc: Subject: c++/9602 Date: 24 Feb 2003 15:29:29 -0000 CVSROOT: /cvs/gcc Module name: gcc Branch: gcc-3_2-branch Changes by: lerdsuwa@gcc.gnu.org 2003-02-24 15:29:29 Modified files: gcc/cp : ChangeLog typeck2.c gcc/testsuite : ChangeLog Added files: gcc/testsuite/g++.dg/template: friend16.C Log message: PR c++/9602 * typeck2.c (abstract_virtuals_error): Don't check when we are processing a template. * g++.dg/template/friend16.C: New test. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_2-branch&r1=1.2685.2.114.2.66&r2=1.2685.2.114.2.67 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/typeck2.c.diff?cvsroot=gcc&only_with_tag=gcc-3_2-branch&r1=1.117.2.2.2.2&r2=1.117.2.2.2.3 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_2-branch&r1=1.1672.2.166.2.99&r2=1.1672.2.166.2.100 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/template/friend16.C.diff?cvsroot=gcc&only_with_tag=gcc-3_2-branch&r1=NONE&r2=1.1.4.1 State-Changed-From-To: analyzed->closed State-Changed-Why: Fixed. From: lerdsuwa@gcc.gnu.org To: gcc-gnats@gcc.gnu.org Cc: Subject: c++/9602 Date: 24 Feb 2003 15:47:25 -0000 CVSROOT: /cvs/gcc Module name: gcc Changes by: lerdsuwa@gcc.gnu.org 2003-02-24 15:47:25 Modified files: gcc/cp : ChangeLog typeck2.c gcc/testsuite : ChangeLog Added files: gcc/testsuite/g++.dg/template: friend16.C Log message: PR c++/9602 * typeck2.c (abstract_virtuals_error): Don't check when TYPE is still template parameter dependent. * g++.dg/template/friend16.C: New test. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&r1=1.3212&r2=1.3213 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/typeck2.c.diff?cvsroot=gcc&r1=1.136&r2=1.137 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.2440&r2=1.2441 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/template/friend16.C.diff?cvsroot=gcc&r1=1.1&r2=1.2 |