Building an Import Library and Export File


For the latest documentation on Visual Studio 2017 RC, see Visual Studio 2017 RC Documentation.

To build an import library and export file, use the following syntax:

LIB /DEF[:deffile] [options] [objfiles] [libraries]  

When /DEF is specified, LIB creates the output files from export specifications that are passed in the LIB command. There are three methods for specifying exports, listed in recommended order of use:

  1. A __declspec(dllexport) definition in one of the objfiles or libraries

  2. A specification of /EXPORT:name on the LIB command line

  3. A definition in an EXPORTS statement in a deffile

These are the same methods you use to specify exports when linking an exporting program. A program can use more than one method. You can specify parts of the LIB command (such as multiple objfiles or /EXPORT specifications) in a command file in the LIB command, just as you can in a LINK command.

The following options apply to building an import library and export file:

/OUT: import
Overrides the default output file name for the import library being created. When /OUT is not specified, the default name is the base name of the first object file or library in the LIB command and the extension .lib. The export file is given the same base name as the import library and the extension .exp.

/EXPORT: entryname[= internalname][,@ ordinal[, NONAME]][, DATA]
Exports a function from your program to allow other programs to call the function. You can also export data (using the DATA keyword). Exports are usually defined in a DLL.

The entryname is the name of the function or data item as it is to be used by the calling program. Optionally, you can specify the internalname as the function known in the defining program; by default, internalname is the same as entryname. The ordinal specifies an index into the export table in the range 1 through 65,535; if you do not specify ordinal, LIB assigns one. The NONAME keyword exports the function only as an ordinal, without an entryname. The DATA keyword is used to export data-only objects.

/INCLUDE: symbol
Adds the specified symbol to the symbol table. This option is useful for forcing the use of a library object that otherwise would not be included.

Note that if you create your import library in a preliminary step, before creating your .dll, you must pass the same set of object files when building the .dll, as you passed when building the import library.

Working with Import Libraries and Export Files