ilist.h fails cpluspluscheck

Peter Eisentraut <peter_e@gmx.net> writes:

In file included from ./src/include/utils/catcache.h:25:0,
from /tmp/cpluspluscheck.bt8VZr/test.cpp:3:
src/include/lib/ilist.h: In function ‘dlist_node* dlist_head_node(dlist_head*)’:
src/include/lib/ilist.h:470:39: error: invalid conversion from ‘void*’ to ‘dlist_node*’ [-fpermissive]

Maybe some ifndef __cplusplus would help.

Or maybe we need to recommend use of -fpermissive? If C++ thinks
casting void * to something else is illegitimate, it's basically not
going to cope with most things we might try to inline in Postgres.
And I don't think that saying "you don't get to call these fundamental
support functions from C++" is likely to fly, so just hiding the
functions won't help much.

regards, tom lane

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On 2012-11-27 01:14:27 -0500, Tom Lane wrote:

Peter Eisentraut <peter_e@gmx.net> writes:

In file included from ./src/include/utils/catcache.h:25:0,
from /tmp/cpluspluscheck.bt8VZr/test.cpp:3:
src/include/lib/ilist.h: In function ‘dlist_node* dlist_head_node(dlist_head*)’:
src/include/lib/ilist.h:470:39: error: invalid conversion from ‘void*’ to ‘dlist_node*’ [-fpermissive]

Maybe some ifndef __cplusplus would help.

Or maybe we need to recommend use of -fpermissive? If C++ thinks
casting void * to something else is illegitimate, it's basically not
going to cope with most things we might try to inline in Postgres.
And I don't think that saying "you don't get to call these fundamental
support functions from C++" is likely to fly, so just hiding the
functions won't help much.

Its rather easy to fix in the ilist code at least - the cases it points
out are those where I took a slightly ugly shortcut to reduce some very
minor code duplication...

Some casts fix it, alternatively the

Assert(!dlist_is_empty());
return head->head.next
could be moved into [ds]list_(head|tail)_node instead of relying on the
*_elemen_off support functions.

Greetings,

Andres

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Andres Freund http://www.2ndQuadrant.com/
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Andres Freund <andres@2ndquadrant.com> writes:

On 2012-11-27 01:14:27 -0500, Tom Lane wrote:

Peter Eisentraut <peter_e@gmx.net> writes:

Maybe some ifndef __cplusplus would help.

Its rather easy to fix in the ilist code at least - the cases it points
out are those where I took a slightly ugly shortcut to reduce some very
minor code duplication...

Some casts fix it,

Seems reasonable, committed.

I wonder if we could get a buildfarm member or two running
cpluspluscheck.

regards, tom lane

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