90366 - xpidl-generated code produces preprocessor warnings

Status: VERIFIED FIXED

(Core :: XPCOM, defect)

Description

[Andrew Chatham]

When xpidl generates the _FORWARD macros, it uses preprocessor concatenation to
join _to and the actual method call. On newer versions of gcc (at least the
version with Red Hat 7.1), the preprocessor spits out a warning, since joining
the two doesn't produce a valid token. Removing all occurrences of ## in xpidl.c
fixes this, and everything still builds fine, but I don't know what it would do
on other compilers, since it leaves a space between the first part and the
method name. I believe that inserting a space, as in "MyClass:: MyMethod()" or
"myobject-> MyMethod()" is just as valid C++ as without the space, but I'm not
sure. This isn't that big a deal, but warnings are annoying, particularly when
they're in autogenerated code.

Comment 1

[David Bradley]

Honestly I don't know why the ## operator was used here. AFAICT it's not needed.
My fear is that some compiler out there, choked without it. McCabe put it in
back in version 1.61. Unfortunately he only stated he put it in and not why.

I'm adding shaver and jband in case they might recall why it was needed.

Comment 2

[David Bradley]

Attachment: Removes ## from xpidl_header.c

Comment 3

[John Bandhauer]

You should say how you've tested this. I assume you've done a full clobber build 
on NT and everything was fine. That would indicate that this is more likely than 
not to work everywhere. Assuming you tested, then r/sr=jband. It looks right to 
me.

Comment 4

[David Bradley]

Yes, I did clobber builds on Win2k and Linux and all was fine.

Comment 5

[Patrick C. Beard]

I'll check this on the Mac build.

Comment 6

[David Bradley]

Moving out.

Comment 7

[Patrick C. Beard]

The Mac build works fine with this patch in place.

Comment 8

[Scott Collins]

sr=scc

Comment 9

[Johnny Stenback (:jst)]

r=jst

Comment 10

[David Bradley]

patch checked in

Comment 11

[Phil Schwartau]

Marking Verified -