[omniORB] BUG: macro expansion problem

[Alex Hornby]

Colin Caughie writes:
 > > -----Original Message-----
 > > From: Alex Hornby [mailto:alex@anvil.co.uk]
 > > Sent: Friday, 7 May 1999 12:47
 > > To: omniorb-list@uk.research.att.com
 > > Subject: [omniORB] BUG: macro expansion problem
 > > 
 > > 
 > > Dear all,
 > > 
 > > Macro expansion is not being done properly, as the ## is left in.
 > > I know macros are nasty, but one of our developers is very 
 > > attached to 
 > > them.
 > > 
 > > ...
 > >
 > > #define EV_TAG(tag) \
 > > 	struct evtag_ ## tag { \
 > > 		tag value; \
 > > 		string errortext; \
 > > 	}
 > 
 > 
 > Have you tried removing the spaces on either side of the ##?
 > 
 > Just a thought,
 > 
 > Colin Caughie (A macro fan!)

Yes, it makes little difference:

Cheers,
Alex.

-- Modified IDL
#pragma prefix "anvil.co.uk"

#define EV_TAG(tag) \
	struct evtag_##tag { \
		tag value; \
		string errortext; \
	}

module example {
    EV_TAG(short);
    EV_TAG(string);
    EV_TAG(long);
    EV_TAG(float);
    EV_TAG(double);
    EV_TAG(Date);
    EV_TAG(DateTime);
    EV_TAG(Currency);
    EV_TAG(Instrument);
    EV_TAG(Agency);
    EV_TAG(Counterparty);
    EV_TAG(Book);
};

-- omniidl2 output
# 1 "/tmp/idli_0gcSQZ.cc" 
#pragma prefix "anvil.co.uk"







module example {
    struct evtag_##short { short value; string errortext; };
    struct evtag_##string { string value; string errortext; };
    struct evtag_##long { long value; string errortext; };
    struct evtag_##float { float value; string errortext; };
    struct evtag_##double { double value; string errortext; };
    struct evtag_##Date { Date value; string errortext; };
    struct evtag_##DateTime { DateTime value; string errortext; };
    struct evtag_##Currency { Currency value; string errortext; };
    struct evtag_##Instrument { Instrument value; string errortext; };
    struct evtag_##Agency { Agency value; string errortext; };
    struct evtag_##Counterparty { Counterparty value; string errortext; };
    struct evtag_##Book { Book value; string errortext; };
};

-- output of cc -E
#pragma	prefix "anvil.co.uk"
# 2 "macro_probem.idl"

# 8

module example {
     struct evtag_short { short value ; string errortext ; };
     struct evtag_string { string value ; string errortext ; };
     struct evtag_long { long value ; string errortext ; };
     struct evtag_float { float value ; string errortext ; };
     struct evtag_double { double value ; string errortext ; };
     struct evtag_Date { Date value ; string errortext ; };
     struct evtag_DateTime { DateTime value ; string errortext ; };
     struct evtag_Currency { Currency value ; string errortext ; };
     struct evtag_Instrument { Instrument value ; string errortext ; };
     struct evtag_Agency { Agency value ; string errortext ; };
     struct evtag_Counterparty { Counterparty value ; string errortext ; };
     struct evtag_Book { Book value ; string errortext ; };
};
#ident "acomp: WorkShop Compilers 4.2 30 Oct 1996 C 4.2"