Can a Visual Studio produced static library, be stripped of symbols?

I'll divide this questions in 3 parts:

1. I would like to produce a static library and strip off its symbols. (Debug info is already not included) Similar to the strip command in linux. Can it be done?

2. Is there an equivalent tool in windows env, to the nm tool in linux?

3. When creating a static library using VS2008. Is it possible to define a script that will exclude some of the produced .obj files out of the build and out of the static lib?

   Can it be dynamic? I mean I'd define a compilation mode in the script and this would result 开发者_StackOverflow社区in specific object files being excluded from the build

If anything is visible that you feel should not be, try declaring it with the "static" keyword. This tells the compiler that it is accessible only to the current module.

There are cases where it would be convenient to be able to strip out all but a small number of "exported" public symbols, but it's not really feasible.

A static library is little more than a collection of .obj files. The internal dependencies haven't been resolved yet, and they won't be resolved until link time.

For example, if your .lib consists of foo.obj and bar.obj, and there's a call in foo.obj to a function defined in bar.obj, then that symbol must be available at link time, even if nothing outside of the library should be able to see it.

For that reason, you cannot strip the symbols (with the possible exception of file-scope static symbols). Even class methods that are protected or private (in the C++-sense) will exist in the symbol table, since the enforcement of the visibility is a compile-time issue, not a link-time one.

In contrast, a dynamic library is a standalone binary that has already been linked. References from foo.obj to bar.obj have already been resolved. Thus a DLL can be stripped of symbols except for the ones that must be exported (and even those can be renamed or replaced by ordinals).

If your DLL exposes a simple C API, then you're all set. But if you want to expose a C++ class, you're probably going to end up exporting all of its methods, even the protected and private ones (since inlining in the external application might result in direct calls to private methods).

1. No, how do you think the users of the static library would link to it without knowing where are the symbols they use defined?
2. Yes, try the DUMPBIN utility.
3. Well, yes. You can run the LIB utility with /REMOVE:foo.

That said, I think you are doing something that either is not worth doing or could be done a lot simpler than with removing library members.

I kept finding the names of certain (but not all) static functions in .obj files produced by VS2010. Interestingly, they were visible in my Release .obj files but not the Debug .obj files. I just used cygwin strings to perform the search:

$ strings myObjectFile.obj | grep myStaticFunctionName

I tracked it down to the "Whole Program Optimization = Yes" setting ("/GL"). When I switched this to "No" the function names no longer appear.

Update: As a followup test I opened the "cleansed" myObjectFile.obj in vim and I can still find them (with either :set encoding=utf-8 or :set encoding=latin1). I'm not sure why strings was missing the matches. Oh well.