[LLVMdev] diffs for vc7.1

[Jeff Cohen]

On Wed, 15 Sep 2004 07:39:23 -0700
Reid Spencer <reid at x10sys.com> wrote:

> Yes, in fact I'd be daring enough to suggest that it be the standard.
> We'll have fewer compilation problems with VC++ 2005 because it is
> (supposedly) more standards compliant than previous versions. Please use
> this download:

While this may be true, it's not a realistic request.  Even among
commercial developers with MSDN subscriptions, it is common to delay
upgrading to the lastest VC++ for a year or two or even three.  I've
personally been involved with two such upgrades, from 5 to 6 and 6 to
7.1 and it's a pain.  The project files are not converted correctly.
Code that compiled before no longer does.  Code that does compile no
longer runs correctly.  You depend on some third-party library that
hasn't itself upgraded to the latest VC++ (still a problem with 7.1). 
And don't even think of doing this near the end of a release cycle for
your product.  The mere thought of using a /beta/ version of a Microsoft
product...

And for those without an MSDN subscription, the cost of purchasing the
latest Visual Studio is enough disincentive.

If the LLVM code base doesn't want to compile with VC++ 6 because it's
not sufficiently ANSI compliant, that's a good enough reason to not
support it.  I know that template support wasn't very compliant with 6
(though still better than most non-g++ Unix compilers even today) and
LLVM uses templates a lot.  While 6 is still common, by now most are
switching to 7.1.  As it seems to work well enough with 7.1, I don't
think standardizing on an unreleased version that won't become dominant
for four years or so is constructive.  And that assumes it actually
ships in 2005 :)