Обсуждение: failed to compile a C++ SPI function

Just for fun I changed the extension of my SPI function and trigger
source file from .c to .C and tried to compile it:

> g++ -g -Wall -I /usr/include/postgresql -fPIC -pedantic    -c -o bid_control.o bid_control.C
> In file included from /usr/include/postgresql/nodes/relation.h:18,
>                  from /usr/include/postgresql/executor/spi.h:18,
>                  from bid_control.h:31,
>                  from bid_control.C:21:
> /usr/include/postgresql/nodes/parsenodes.h:871: parse error before `typename'

It seems the "typename" word used in the following structure is a
reserved word in C++. (and is appears colored like a type in Vim)

> /*
>  * ParamNo - specifies a parameter reference
>  */
> typedef struct ParamNo
> {
>     NodeTag     type;
>     int         number;         /* the number of the parameter */
>     TypeName   *typename;       /* the typecast */                 ^^^^^^^^^
>     List       *indirection;    /* array references */
> } ParamNo;

Is it totally unreasonable try C++ in SPI programming?

Cheers,


-- 
Louis-David Mitterrand - ldm@apartia.org - http://www.apartia.org

Isn't vi that text editor with two modes... one that beeps and one
that corrupts your file?" -- Dan Jocabson, on comp.os.linux.advocacy

I am willing to change it to typname.  Any comments?

> Just for fun I changed the extension of my SPI function and trigger
> source file from .c to .C and tried to compile it:
> 
> > g++ -g -Wall -I /usr/include/postgresql -fPIC -pedantic    -c -o bid_control.o bid_control.C
> > In file included from /usr/include/postgresql/nodes/relation.h:18,
> >                  from /usr/include/postgresql/executor/spi.h:18,
> >                  from bid_control.h:31,
> >                  from bid_control.C:21:
> > /usr/include/postgresql/nodes/parsenodes.h:871: parse error before `typename'
> 
> It seems the "typename" word used in the following structure is a
> reserved word in C++. (and is appears colored like a type in Vim)
> 
> > /*
> >  * ParamNo - specifies a parameter reference
> >  */
> > typedef struct ParamNo
> > {
> >     NodeTag     type;
> >     int         number;         /* the number of the parameter */
> >     TypeName   *typename;       /* the typecast */
>                   ^^^^^^^^^
> >     List       *indirection;    /* array references */
> > } ParamNo;
> 
> Is it totally unreasonable try C++ in SPI programming?
> 
> Cheers,
> 
> 
> -- 
> Louis-David Mitterrand - ldm@apartia.org - http://www.apartia.org
> 
> Isn't vi that text editor with two modes... one that beeps and one
> that corrupts your file?" -- Dan Jocabson, on comp.os.linux.advocacy
> 


--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
853-3000+  If your life is a hard drive,     |  830 Blythe Avenue +  Christ can be your backup.        |  Drexel Hill,
Pennsylvania19026
 

Bruce Momjian <pgman@candle.pha.pa.us> writes:
> I am willing to change it to typname.  Any comments?

That's hardly the only change you will have to make to get the headers
to pass through a C++ compiler without complaint.  How many existing
applications do you want to risk breaking?

ParamNo probably isn't a widely used node type, but there are four
structs with fields named 'typename' and one with a field named 'class'
just in parsenodes.h.

I think that before we start making changes with C++ cleanness as a
goal, we should try to get a precise idea of the extent of the changes
that would be needed, and then estimate how much user code might
reference the fields we'd need to rename.
        regards, tom lane

> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > I am willing to change it to typname.  Any comments?
> 
> That's hardly the only change you will have to make to get the headers
> to pass through a C++ compiler without complaint.  How many existing
> applications do you want to risk breaking?
> 
> ParamNo probably isn't a widely used node type, but there are four
> structs with fields named 'typename' and one with a field named 'class'
> just in parsenodes.h.
> 
> I think that before we start making changes with C++ cleanness as a
> goal, we should try to get a precise idea of the extent of the changes
> that would be needed, and then estimate how much user code might
> reference the fields we'd need to rename.

Agreed.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
853-3000+  If your life is a hard drive,     |  830 Blythe Avenue +  Christ can be your backup.        |  Drexel Hill,
Pennsylvania19026