Re: [Boost-Users] boost::signals build and C++Builder 6 Pro in 1.29.0

From: Peter Dimov (pdimov_at_[hidden])
Date: 2003-03-05 05:46:33

Russell Hind wrote:
> I have built the boost::signals library with C++Builder 6 Pro Update 4
> and am running into problems:

[...]

> b)  If I do use quad word alignment, then the object constructs
> correctly, but when I connect a method to it with
>
> void VoidFunc(void)
> {
> }
>
> int main(int argc, char* argv[])
> {
> boost::signal0<void> s;
>      s.connect(&VoidFunc);
> }
>
> the program hangs.  Turning on CodeGuard shows a similar problem to
> that
> above.  The object was allocated with a size of 12 bytes, but code is
> trying to access byte 16 in the object (I guess this is a similar
> alignment problem).  The callstack is
>
> 0041E44E boost::counted_base::dispose(this=:00C04360)

counted_base::dispose() is an empty function, so this looks like a CodeGuard
false alarm.

One possible reason for the real problem is runtime library mismatch between
the signals library and your executable. counted_base contains a mutex in
multithreaded builds.

> Do (or should) all the bost headers force alignment before all
> structures/classes and then restore the alignment afterwards?

No. The compiler options used to build the application and the libraries it
depends on must match. The headers cannot magically fix the (general)
problem for you; even if we focus on one particular compiler/platform - and
we shouldn't - some of the options are global.

> Currently, I have to link directly with the signals source code to get
> use the library.

This is what I'd do, too. The other alternative is to build several .lib
files that match the options specified in your various project
configurations (Debug, Debug MT, Release, Release MT, or however their
canonical names are in BCB).