The MSDN documentation on dllexport contains the following enigmatic paragraph, or at least did at the time I wrote this article:
dllexport of a C++ function will expose the function with C++ name mangling. If C++ name mangling is not desired, either use a .def file (EXPORTS keyword) or declare the function as extern "C".
I've seen this sentence misinterpreted as follows:
dllexport of a C++ function will expose the function with C++ name mangling. To disable name mangling either use a .def file (EXPORTS keyword) or declare the function as extern "C".
This is an understandable misinterpretation, but it is still a misinterpretation.
The root cause of the misinterpretation is that the author of this documentation was wearing C++-colored glasses. In the author's mind, there are only two interesting cases:
- C++ name mangling, where all the cool people are, and
- everything else, for all the lamers.
Here is a precise formulation of the paragraph:
dllexport of a C++ function will expose the function with C++ name mangling. If C++ name mangling is not desired, either use a .def file (EXPORTS keyword), which will expose the name without mangling, or declare the function as extern "C", which will expose the name with C mangling.
Here's a version of the paragraph that tries to take away the C++-colored glasses.
dllexport exposes the function as it is decorated by the compiler.
For example,
if the function is a C++ function, it will be exposed with C++ name
mangling.
If the function is a C function, or has been declared as
extern "C",
it will be exposed with C name mangling.
To expose the function under its unmangled name (or to expose it
via an alternate name), use
use a .def file (EXPORTS keyword).
Behind the scenes:
To forestall nitpickers, I had to go back to my copy of the C++
standard to make sure I filled in the blank in
"The extern "C" _________" correctly.
Officially, extern "C" is a storage class specifier.