public inbox for gcc-prs@sourceware.org help / color / mirror / Atom feed
From: jody@ifi.unizh.ch To: gcc-gnats@gcc.gnu.org Subject: c++/6006: problem with pure virtual functions and destructord Date: Tue, 19 Mar 2002 10:06:00 -0000 [thread overview] Message-ID: <20020319175836.8358.qmail@sources.redhat.com> (raw) >Number: 6006 >Category: c++ >Synopsis: problem with pure virtual functions and destructord >Confidential: no >Severity: non-critical >Priority: medium >Responsible: unassigned >State: open >Class: sw-bug >Submitter-Id: net >Arrival-Date: Tue Mar 19 10:06:00 PST 2002 >Closed-Date: >Last-Modified: >Originator: jody weissmann >Release: gcc version 2.95.2 19991024 (release) >Organization: >Environment: sparc-sun-solaris2.8 >Description: A pure virtual method f() of a class A CANNOT be called from within the destructor ~A of the class A. However, it can be called from within a normal method g() of A. But strangely enough, g() can be called from within the destructor ~A of A. The error message created when f9) is called from within ~A: Undefined first referenced symbol in file A::f(void) BugProg.o ld: fatal: Symbol referencing errors. No output written to BugProg collect2: ld returned 1 exit status >How-To-Repeat: The error appears when the program below is compiled: g++ -o BugProg BugProg.cpp Here comes the source of BugProg.cpp //------------------------------------- // BugProg.cpp // //------------------------------------- //------------------------------------- // declaration of A // class A { public: A(void); ~A(void); virtual void f(void)=0; void g(void); }; //------------------------------------- // implementation of B // class B : public A { public: B(void); virtual void f(void); }; //------------------------------------- // implementation of A // A::A(void) { } A::~A(void) { f(); // this doesn't work g(); // but this works } void A::g(void) { f(); } //------------------------------------- // implementation of B // B::B(void) : A() { } void B::f(void) { } //------------------------------------- // main // void main(void) { B *pB = new B(); delete pB; } >Fix: Workaround: if a normal method g() of A calls the pure virtual method f() of A, then g() can be called from within the destructor >Release-Note: >Audit-Trail: >Unformatted: ----gnatsweb-attachment---- Content-Type: application/octet-stream; name="BugProg.ii" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="BugProg.ii" IyAxICJCdWdQcm9nLmNwcCIKIAogCiAKY2xhc3MgQSB7CnB1YmxpYzoKICBBKHZvaWQpOwogfkEo dm9pZCk7CiAKICB2aXJ0dWFsIHZvaWQgZih2b2lkKT0wOwogIHZvaWQgZyh2b2lkKTsKfTsKCgog CiAKIApjbGFzcyBCIDogcHVibGljIEEgewpwdWJsaWM6CiAgQih2b2lkKTsKIAogIHZpcnR1YWwg dm9pZCBmKHZvaWQpOwp9OwoKCiAKIAogCkE6OkEodm9pZCkgewp9CgpBOjp+QSh2b2lkKSB7CiAg ZigpOyAgICAgCiAgZygpOyAgICAgIAp9Cgp2b2lkIEE6Omcodm9pZCkgewogIGYoKTsKfSAgCgoK IAogCiAKQjo6Qih2b2lkKSAKICA6IEEoKSB7Cn0KCnZvaWQgQjo6Zih2b2lkKSB7Cn0KCgogCiAK IAp2b2lkIG1haW4odm9pZCkgewogIEIgKnBCID0gbmV3IEIoKTsKICBkZWxldGUgcEI7Cn0K
next reply other threads:[~2002-03-19 18:06 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2002-03-19 10:06 jody [this message] 2002-05-14 8:46 lerdsuwa 2002-05-15 1:46 jody 2002-05-15 3:16 Nathan Sidwell
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20020319175836.8358.qmail@sources.redhat.com \ --to=jody@ifi.unizh.ch \ --cc=gcc-gnats@gcc.gnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).