Re: [lmi] fixing "type attributes are honored only at type definition" warning

[Greg Chicares]

On 2008-03-07 21:33Z, Vaclav Slavik wrote:
> 
> now that wx-2.8.7 is used for MSW builds, can we change forward
> declarations of wx classes to use WXDLLIMPEXP_FWD_CORE instead
> of WXDLLEXPORT? It will fix gcc4's "type attributes are honored
> only at type definition" warning in code using forward declaration
> of wx classes.

Committed 20080309T1213Z, following your exact instructions.

> The change is probably better described by a sed script than a patch:

Yes, good idea. [script snipped]

> Additionally, -Wno-attributes is no longer needed and can be removed from
> workhorse.make

I applied your 'workhorse.make' patch at the same time.

> (assuming there are no forgotten places in wx headers
> themselves that would cause problems in 2.8.7 -- I couldn't test it, I don't
> know how to setup MSW makefiles to use gcc 4.2

It should be as easy as changing a Cygwin mount. Here's what we
use for production (MinGW gcc-3.4.4):
  mount -f -s -b "C:/MinGW-20050827" "/MinGW_"
This would use Cygwin's own gcc (with '-mno-cygwin') instead:
  mount -f -s -b "C:/cygwin" "/MinGW_"
I actually built lmi that way, and it seems to run, though IIRC
it would use Cygwin's filesystem, which would be a problem for
our end users. This (depending on where you install it):
  mount -f -s -b "C:/cygwin/MinGW-20070825-sjlj" "/MinGW_"
would use MinGW gcc-4.x; it finds issues with boost (which you
might be able to override with
  treat_warnings_as_errors='' make any_lmi_target
but I didn't try that), and of course it requires building wx
with the same compiler (which I didn't do). I'm not putting any
time into moving to MinGW gcc-4.x myself because
 - some boost issues would need to be fixed
 - I'm not sure its shared libstdc++ really works
 - IIRC, its '-dw2' version doesn't handle C++ exceptions thrown
   across dll boundaries (but the '-sjlj' version should)
 - I don't have a compelling need to stop using gcc-3.x
but you're welcome to try.