Bug in g++ 2.95.4 (Pointer to member functions)

[Paul Marquis]

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I think your public methods for the class Class should be static.

On Tuesday 29 April 2003 10:38 am, Simon Barner wrote:
> Hi,
>
> I think I have discovered a bug in FreeBSD 4.8-STABLE's system C++
> compiler:
>
> % gcc -v
> % Using builtin specs.
> % gcc version 2.95.4 20020320 [FreeBSD]
>
> Here is a stripped down example that can be used to reproduce the
> bug:
>
> // ----------- begin bug.cpp -----------
> #include <iostream>
> class Class {
> 	public:
> 		void M1 (void) { cout << "M1" << endl; };
> 		void M2 (void) { cout << "M2" << endl; };
> 		void M3 (void) { cout << "M3" << endl; };
> };
>
> typedef  void (Class::*ClassMemberFn)(void);
> #define callMemberFunction(object,ptrToMember) 
> ((object).*(ptrToMember))
>
> int main (int argc, char* argv[]) {
> 	Class obj;
>
> 	// This works fine: Array size == 2
> 	ClassMemberFn a[2] = { &Class::M1, &Class::M2};
> 	for (unsigned int i=0; i<2; ++i) {
> 		callMemberFunction (obj, a[i]) ();
> 	}
>
>
> 	// This will cause the internal compiler error: Array size > 2
> 	ClassMemberFn b[3] = { &Class::M1, &Class::M2,&Class::M3};
> 	for (unsigned int i=0; i<3; ++i) {
> 		callMemberFunction (obj, b[i]) ();
> 	}
> 	return 0;
> }
>
> // ----------- end bug.cpp -----------
>
>
> This is how you can reproduce the internal compiler error:
> % gcc -c bug.cpp
> % bug.cpp: In function `int main(int, char **)':
> % bug.cpp:20: Internal compiler error in `const_hash', at
> varasm.c:2373 % Please submit a full bug report.
> % See <URL:http://www.gnu.org/software/gcc/bugs.html> for
> instructions.
>
> I have tested the same source (which is an adoption from the C++
> FAQ-lite,
> http://www.parashift.com/c++-faq-lite/pointers-to-members.html) an
> the following systems:
>
> Success:
>    GCC 2.9.2, SunOS 5.8 Generic_108528-19 sun4u sparc SUNW,Ultra-60
>    GCC 3.2.2, SunOS 5.8 Generic_108528-19 sun4u sparc SUNW,Ultra-60
>    GCC 2.9.6 (redhat) , Linux athalle1 2.4.18-27.7.xsmp #1 SMP
>
> Same compiler error:
>    GCC 2.9.2, Linux athalle1 2.4.18-27.7.xsmp #1 SMP
>
> My conclusion is, that this bug is i386 specific, and that it has
> been fixed in g++ 3.x and Redhat's 2.96 proprietary version.
>
> What should I do (apart from using gcc 3.x from the ports
> collection)?
>
> Should I file a bug at the GCC gnats site, but I think they do not
> maintain GCC 2.9.4 any longer (I have seen according comments at
> the end of closed bug reports)?
>
> Or should I send a PR? Is there any chance that this bug will be
> fixed?
>
> I also had a look at the gcc source file from that error message,
> but it's not very helpful as it's the location of an abort () call
> only...
>
> Cheers,
>  Simon

- -- 
Paul Marquis
pmarquis at pobox.com
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