internal compiler error: in cp_build_indirect_ref, at cp/typeck.c:2786

[David Kastrup]

DEPENDENCIES_OUTPUT="./out/part-combine-iterator.dep ./out/part-combine-iterator.o" g++ -c -Woverloaded-virtual -I/usr/include/python2.7 -I/usr/include/python2.7 -fno-strict-aliasing -g -fwrapv -g -fstack-protector --param=ssp-buffer-size=4 -DHAVE_CONFIG_H -I./include -I./out -I../flower/include -I../flower/./out -I../flower/include -g -pipe -fno-optimize-sibling-calls -pthread -I/usr/include/freetype2 -pthread -I/usr/include/pango-1.0 -I/usr/include/freetype2 -I/usr/include/glib-2.0 -I/usr/lib/i386-linux-gnu/glib-2.0/include -Wno-pmf-conversions -W -Wall -Wconversion -o out/part-combine-iterator.o part-combine-iterator.cc
part-combine-iterator.cc: In member function ‘virtual void Part_combine_iterator::derived_mark() const’:
part-combine-iterator.cc:173:40: internal compiler error: in cp_build_indirect_ref, at cp/typeck.c:2786
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.6/README.Bugs> for instructions.
Preprocessed source stored into /tmp/cc6YKx3d.out file, please attach this to your bugreport.

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: g++-4.6 4.6.3-1ubuntu5
ProcVersionSignature: Ubuntu 3.2.0-23.36-generic 3.2.14
Uname: Linux 3.2.0-23-generic i686
ApportVersion: 2.0.1-0ubuntu4
Architecture: i386
Date: Wed Apr 18 07:38:40 2012
ExecutablePath: /usr/lib/gcc/i686-linux-gnu/4.6/cc1plus
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111011)
SourcePackage: gcc-4.6
UpgradeStatus: Upgraded to precise on 2012-04-11 (6 days ago)

[Doko-v (doko-v)]

Created attachment 27203
preprocessed source

seen with 4.6 and 4.7 branches, and trunk on i686-linux-gnu

$ gcc -c -g part-combine-iterator.ii
part-combine-iterator.cc: In member function 'virtual void Part_combine_iterator::derived_mark() const':
part-combine-iterator.cc:173:40: internal compiler error: in cp_build_indirect_ref, at cp/typeck.c:2836
Please submit a full bug report,
with preprocessed source if appropriate.

[Matthias Klose (doko)]

seen with 4.6, 4.7 and trunk

[Rguenth (rguenth)]

Created attachment 27204
unincluded testcase

4.4 rejects it:

part-combine-iterator.cc: In member function 'virtual void Part_combine_iterator::derived_mark() const':
part-combine-iterator.cc:173: error: invalid use of '' on pointer to member

4.5 also ICEs the same way.

[David Kastrup (dak)]

Just for the record: the source code triggering the error is invalid C++. It is just that an internal compiler error is a somewhat intimidating diagnostic.

[Marc-glisse (marc-glisse)]

A brutal application of delta gives this short but non-sensical code:

void f () ;
struct A A :: * p ;
int i = p ->* f ;

[Glisse-6 (glisse-6)]

Created attachment 27390
patch 1

ice.cc:2:15: error: pointer to member must be on the right side of '->*'
 int i = p ->* p ;
               ^

so the caret is on the wrong side of the operator.

[Paolo-carlini (paolo-carlini)]

If the patch otherwise works fine, I would encourage you to submit it anyway even if the caret isn't accurate: AFAICS, for all the errors emitted by that function the caret is at the end of the expression and fixing that may be conceptually simple but I don't think boils down to 10 or 20 lines, it seems a separate issue really.

[Manu-gcc (manu-gcc)]

Sorry, I think your message is not easily understandable. I think you are trying to say that "the right hand side must be a pointer-to-member", but this is not actually what your proposed message says.

I like more clang's message:

/tmp/webcompile/_28618_0.cc:4:11: error: right hand operand to ->* has non pointer-to-member type 'void ()'
int i = p ->* f ;
          ^ ~

I am not saying that you need to print the type or fix the location (it would be nice but I understand it is quite extra work, and could be done later). But the text could say: "type of right-side operand of %<->*%> is not pointer-to-member", or "right-side operand of %<->*%> has non pointer-to-member type" or "right-side operand of %<->*%> must have pointer-to-member type".

[Paolo-carlini (paolo-carlini)]

As long as we avoid the ICE and the message is fine I'm happy. Then I'll take care of the column number asap.

[Glisse-6 (glisse-6)]

Note: this is very old, I barely remember it.

(In reply to comment #6)
> Sorry, I think your message is not easily understandable. I think you are
> trying to say that "the right hand side must be a pointer-to-member",

No, I think I am saying: hello, this is the left hand side of a ->* operator, and you are feeding me a pointer to member, which obviously should be on the right hand side.

> I like more clang's message:
>
> /tmp/webcompile/_28618_0.cc:4:11: error: right hand operand to ->* has non
> pointer-to-member type 'void ()'
> int i = p ->* f ;
> ^ ~

The testcase in the patch has p ->* p, and clang says:

test.cc:2:11: error: left hand operand to ->* must be a pointer to class
      compatible with the right hand operand, but is 'struct A::*'
int i = p ->* p ; // { dg-error "" }
          ^~~
          .*

(not sure what that .* is doing there)

> I am not saying that you need to print the type or fix the location (it would
> be nice but I understand it is quite extra work, and could be done later). But
> the text could say: "type of right-side operand of %<->*%> is not
> pointer-to-member", or "right-side operand of %<->*%> has non pointer-to-member
> type" or "right-side operand of %<->*%> must have pointer-to-member type".

IIRC (and I could be wrong), this test is really about the lhs. Which doesn't mean that the error message is good...

[Manu-gcc (manu-gcc)]

(In reply to comment #8)
> Note: this is very old, I barely remember it.
>
> (In reply to comment #6)
> > Sorry, I think your message is not easily understandable. I think you are
> > trying to say that "the right hand side must be a pointer-to-member",
>
> No, I think I am saying: hello, this is the left hand side of a ->* operator,
> and you are feeding me a pointer to member, which obviously should be on the
> right hand side.

Ah! I was looking at the testcase here and I got confused.

> test.cc:2:11: error: left hand operand to ->* must be a pointer to class
> compatible with the right hand operand, but is 'struct A::*'
> int i = p ->* p ; // { dg-error "" }
> ^~~
> .*
>
> (not sure what that .* is doing there)

Me neither, but clang's text is clearer in my humble opinion. I will be happy with the text changed to "left-side operand of %<->*%> must a pointer to class compatible with the right-side operand", and everything the same as your current patch. Please submit that!

[Glisse-6 (glisse-6)]

Author: glisse
Date: Fri Oct 12 14:14:37 2012
New Revision: 192401

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=192401
Log:
2012-10-12 Marc Glisse <email address hidden>

 PR c++/53055

gcc/c-family/
 * c-common.h (enum ref_operator) [RO_ARROW_STAR]: New.

gcc/cp/
 * call.c (build_new_op_1): Pass RO_ARROW_STAR to cp_build_indirect_ref.
 * typeck.c (cp_build_indirect_ref): Handle RO_ARROW_STAR.

gcc/testsuite/
 * g++.dg/pr53055.C: New testcase.

Added:
    trunk/gcc/testsuite/g++.dg/pr53055.C (with props)
Modified:
    trunk/gcc/c-family/ChangeLog
    trunk/gcc/c-family/c-common.h
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/call.c
    trunk/gcc/cp/typeck.c
    trunk/gcc/testsuite/ChangeLog

Propchange: trunk/gcc/testsuite/g++.dg/pr53055.C
            ('svn:eol-style' added)

Propchange: trunk/gcc/testsuite/g++.dg/pr53055.C
            ('svn:keywords' added)

[Glisse-6 (glisse-6)]

(In reply to comment #7)
> Then I'll take care of the column number asap.

Ok, your turn ;-)

(In reply to comment #9)
> I will be happy
> with the text changed to "left-side operand of %<->*%> must a pointer to class
> compatible with the right-side operand",

I went with: "left hand operand of ->* must be a pointer to class, but is a pointer to member of type ...", the bit about the RHS didn't seem relevant to this particular error. But you still have a chance to convince Paolo for the follow-up patch...

[Paolo-carlini (paolo-carlini)]

Great. This is fixed anyway.