V22.0201.002, Machine Organization I; Professor Yap
Fall 1997

NOTES ON TURBO LIBRARY

The following notes are taken directly from the Turbo Assembler 5.0 distribution. The part that is most relevant to us is the second half, concerning TLIB. The Microsoft version of TLIB is called LIB and is discussed in the text, chapter 14. There are many similarities between TLIB and LIB, of course.

We recommend that you skip the first part, and go directly to TLIB below. You may be able to immediately use TLIB just by looking at the examples below!

/*************************************************************************/
                                 TLIB.TXT
                              TURBO ASSEMBLER

This file contains details on using TLIB with TASM.

--------------------------------------------------------------------
                        TABLE OF CONTENTS
                        - - - - - - - - -
   Using IMPLIB: The import librarian
   Using IMPDEF: The module-definition file manager
      Classes in a DLL
      Functions in a DLL
   Using TLIB: the Turbo Librarian
      Why use object module libraries?
      The TLIB command line
         Using response files
         Using case-sensitive symbols: The /C option
         Creating an extended dictionary: The /E option
         Setting the page size: The /P option
         Removing comment records: The /0 option
         The operation list
      Examples

--------------------------------------------------------------------

This chapter describes several tools that let you work with library
files.

  o  IMPLIB creates import libraries, and IMPDEF creates module
     definition files (.DEF files). Import libraries and module
     definition files provide information to the linker about
     functions imported from dynamic-link libraries (DLLs).

  o  TLIB is a utility that manages libraries of individual .OBJ
     (object module) files. A library is a convenient tool for
     dealing with a collection of object modules as a single unit.


Using IMPLIB: The import librarian
==================================
The IMPLIB utility creates import libraries. IMPLIB takes as input
DLLs, module definition files, or both, and produces an import library
as output. When you add a DLL as a target, the project manager
compiles and links the DLL's dependent files to create the .DLL file,
then runs IMPLIB to create a .LIB file.

Import libraries contain records. Each record contains the name of a
DLL, and specifies where in the DLL the imported functions reside.
These records are bound to the application by TLINK or the IDE linker,
and provide Windows with the information necessary to resolve DLL
function calls. An import library can be substituted for part or all
of the IMPORTS section of a module definition file.

If you've created a Windows application, you've already used at least
one import library, IMPORT.LIB, the import library for the standard
Windows DLLs.

An import library lists some or all of the exported functions for one
or more DLLs. IMPLIB creates an import library directly from DLLs or
from module definition files for DLLs (or a combination of the two).

To create an import library for a DLL, type

	IMPLIB Options LibName [DefFiles...|DLLs...]

where 'Options' is an optional list of one or more IMPLIB options,
'LibName' is the name for the new import library, 'DefFiles' is a list
of one or more existing module definition files for one or more DLLs,
and 'DLLs' is a list of one or more existing DLLs. You must specify at
least one DLL or module definition file.

A DLL can also have an extension of .EXE or .DRV, not just .DLL.

Options must be lowercase and preceded by either a hyphen or a slash.

Option		Description
------		-----------
-c		Accepts case-sensitive symbols. If you have two symbols
		that differ only in case (like MYSYM and mysym) and you
		don't use -c, IMPLIB uses the first symbol and treats
		the second one as a duplicate.

-i		Tells IMPLIB to ignore WEP, the Windows exit procedure
		required to end a DLL. Use this option if you are
		specifying more than one DLL on the IMPLIB command line.

-w		No warnings.


Using IMPDEF: The module-definition file manager
================================================
IMPDEF takes as input a DLL name, and produces as output a module
definition file with an export section containing the names of
functions exported by the DLL. The syntax is

	IMPDEF DestName.DEF SourceName.DLL

This creates a module definition file named 'DestName'.DEF from the
file 'SourceName'.DLL. The resulting module definition file would look
something like this:

	LIBRARY     FileName

	DESCRIPTION 'Description'

	EXPORTS
		ExportFuncName      @Ordinal
		ExportFuncName      @Ordinal

where 'FileName' is the DLL's root file name, 'Description' is the
value of the DESCRIPTION statement if the DLL was previously linked
with a module definition file that included a DESCRIPTION statement,
'ExportFuncName' names an exported function, and 'Ordinal' is that
function's ordinal value (an integer).


Classes in a DLL
----------------
IMPDEF is useful for a DLL that uses C++ classes. If you use the
_export keyword when defining a class, all of the non-inline member
functions and static data members for that class are exported. It's
easier to let IMPDEF make a module definition file for you because it
lists all the exported functions, and automatically includes the
member functions and static data members.

Since the names of these functions are mangled, it would be tedious to
list them all in the EXPORTS section of a module definition file
simply to create an import library from the module definition file. If
you use IMPDEF to create the module definition file, it includes the
ordinal value for each exported function. If the exported name is
mangled, IMPDEF also includes that function's unmangled, original name
as a comment following the function entry. So, for instance, the
module definition file created by IMPDEF for a DLL that used C++
classes would look something like this:

	LIBRARY     FileName

	DESCRIPTION 'Description'

	EXPORTS
		MangledExportFuncName  @Ordinal ; ExportFuncName
		MangledExportFuncName  @Ordinal ; ExportFuncName

where 'FileName' is the DLL's root file name, 'Description' is the
value of the DESCRIPTION statement if the DLL was previously linked
with a module definition file that included a DESCRIPTION statement,
'MangledExportFuncName' provides the mangled name, 'Ordinal' is that
function's ordinal value (an integer), and 'ExportFuncName' gives the
function's original name.


Functions in a DLL
------------------
IMPDEF creates an editable source file that lists all the exported
functions in the DLL. You can edit this .DEF file to contain only
those functions that you want to make available to a particular
application, then run IMPLIB on the edited .DEF file. This results in
an import library that contains import information for a specific
subset of a DLL's export functions.

Suppose you're distributing a DLL that provides functions to be used
by several applications. Every export function in the DLL is defined
with _export. Now, if all the applications used all the DLL's exports,
then you could use IMPLIB to make one import library for the DLL. You
could deliver that import library with the DLL, and it would provide
import information for all of the DLL's exports. The import library
could be linked to any application, thus eliminating the need for the
particular application to list every DLL function it uses in the
IMPORTS section of its module definition file.

But let's say you want to give only a few of the DLL's exports to a
particular application. Ideally, you want a customized import library
to be linked to that application--an import library that provides
import information only for the subset of functions that the
application uses. All of the other export functions in the DLL are
hidden to that client application.

To create an import library that satisfies these conditions, run
IMPDEF on the compiled and linked DLL. IMPDEF produces a module
definition file that contains an EXPORT section listing all of the
DLL's export functions. You can edit that module definition file,
remove the EXPORTS section entries for those functions you don't want
in the customized import library, and then run IMPLIB on the module
definition file. The result is an import library that contains import
information for only those export functions listed in the EXPORTS
section of the module definition file.


Using TLIB: the Turbo Librarian

=============================== When it modifies an existing library, TLIB always creates a copy of the original library with a .BAK extension. You can use TLIB to build and modify your own libraries, libraries furnished by other programmers, or commercial libraries you've purchased. You can also use TLIB to: o Create a new library from a group of object modules. o Add object modules or other libraries to an existing library. o Remove object modules from an existing library. o Replace object modules from an existing library. o Extract object modules from an existing library. o List the contents of a new or existing library. Why use object module libraries? -------------------------------- When you program, you often create a collection of useful functions. With modular programming, you are likely to split those functions into many separately compiled source files. Any particular program might use only a subset of functions from the entire collection. An object module library manages a collection of functions and classes. When you link your program with a library, the linker scans the library and automatically selects only those modules needed for the current program. The TLIB command line --------------------- The TLIB command line takes the following general form, where items listed in square brackets are optional: tlib [@respfile] [option] libname [operations] [, listfile] Option Description ------ ----------- @respfile The path and name of the response file you want to include. You can specify more than one response file. libname The DOS path name of the library you want to create or manage. Every TLIB command must be given a libname. Wildcards are not allowed. TLIB assumes an extension of .LIB if none is given. (It's best to use only the .LIB extension.) NOTE: If the named library does not exist and there are 'add' operations, TLIB creates the library. /C The case-sensitive flag. This option is not normally used. /E Creates Extended Dictionary. /Psize Sets the library page size to 'size'. /0 Removes comment records from the library. operations The list of operations TLIB performs. Operations can appear in any order. If you only want to examine the contents of the library, don't give any operations. listfile The name of the file that lists library contents. It must be preceded by a comma. No listing is produced if you don't give a file name. The listing is an alphabetical list of each module. The entry for each module contains an alphabetical list of each public symbol defined in that module. The default extension for the 'listfile' is .LST. You can direct the listing to the screen by using the 'listfile' name CON, or to the printer by using the name PRN. Using response files - - - - - - - - - - - When you use a large number of operations, or if you find yourself repeating certain sets of operations over and over, you will probably want to use response files. A response file is an ASCII text file that contains all or part of a TLIB command. Using response files, you can build TLIB commands larger than would fit on one command line. Response files can: o Contain more than one line of text; use the ampersand character (&) at the end of a line to indicate that another line follows. o Include a partial list of commands. You can combine options from the command line with options in a response file. o Be used with other response files in a single TLIB command line. Using case-sensitive symbols: The /C option - - - - - - - - - - - - - - - - - - - - - - TLIB maintains a dictionary of all public symbols defined in the modules of the library. When you add a module to a library, its symbol must be unique. If you try to add a module to the library that duplicates a symbol, TLIB displays an error message and doesn't add the module. NOTE: Don't use /C if you plan to use the library with other linkers or let other people use the library. Because some linkers aren't case-sensitive, TLIB rejects symbols that differ only in case (for example, the symbols 'lookup' and 'LOOKUP' are treated as duplicates). TLINK, however, can distinguish case, so if you use your library only with TLINK, you can use the TLIB /C option to add a module to a library that includes symbols differing only in case. Creating an extended dictionary: The /E option - - - - - - - - - - - - - - - - - - - - - - - - To increase the linker's capacity for large links, you can use TLIB to create an extended dictionary and append it to the library file. This dictionary contains, in a compact form, information that is not included in the standard library dictionary and that lets the linker (TLINK) preprocess library files so that any unnecessary modules are not preprocessed. To create an extended dictionary for a library that you're modifying, use the /E option when you start TLIB to add, remove, or replace modules in the library. You can also use the /E option to create an extended dictionary for an existing library that you don't want to modify. For example, if you type "TLIB /E mylib" the linker appends an extended dictionary to the specified library. If you use /E to add a library module containing a C++ class with a virtual function, you'll get the error message "Library contains COMDEF records--extended dictionary not created". Setting the page size: The /P option - - - - - - - - - - - - - - - - - - Every DOS library file contains a dictionary that appears at the end of the .LIB file, following all of the object modules. For each module in the library, the dictionary contains a 16-bit address of that particular module within the .LIB file; this address is given in terms of the library page size (it defaults to 16 bytes). The library page size determines the maximum combined size of all object modules in the library, which cannot exceed 65,536 pages. The default (and minimum) page size of 16 bytes allows a library of about 1 MB in size. To create a larger library, use the /P option to increase the page size. The page size must be a power of 2, and it cannot be smaller than 16 or larger than 32,768. All modules in the library must start on a page boundary. For example, in a library with a page size of 32 (the lowest possible page size higher than the default 16), an average of 16 bytes is lost per object module in padding. If you attempt to create a library that is too large for the given page size, TLIB issues an error message and suggests that you use /P with the next available higher page size. Removing comment records: The /0 option - - - - - - - - - - - - - - - - - - - - Use the /0 option to remove comment records, which reduces the size of a library. For example, you might have debugging or browsing information in a library, but you no longer need to use that information; the /0 option removes that information. The operation list - - - - - - - - - - The operation list describes what actions you want TLIB to do. It consists of a sequence of operations given one after the other. Each operation consists of a one- or two-character action symbol followed by a file or module name. You can put whitespace around either the action symbol or the file or module name but not in the middle of a two-character action or in a name. You can put as many operations as you like on the command line, up to 126 characters. The order of the operations is not important. TLIB always applies the operations in a specific order: 1) All extract operations are done first. 2) All remove operations are done next. 3) All add operations are done last. TLIB finds the name of a module by stripping any drive, path, and extension information from the given file name. TLIB always assumes reasonable defaults. For example, to add a module that has an .OBJ extension from the current directory, you need to supply only the module name, not the path and .OBJ extension. TLIB recognizes three action symbols (-, +, *), which you can use singly or combined in pairs for a total of five distinct operations. The action symbols and what they do are listed here: Symbol Name Description ------ ---- ----------- + Add TLIB adds the named file to the library. If the file has no extension, TLIB assumes an extension of .OBJ. If the file is itself a library (with a .LIB extension), then the operation adds all of the modules in the named library to the target library. If a module being added already exists, TLIB displays a message and does not add the new module. - Remove TLIB removes the named module from the library. If the module does not exist in the library, TLIB displays a message. A remove operation needs only a module name. TLIB lets you enter a full path name with drive and extension included, but ignores everything except the module name. * Extract TLIB creates the named file by copying the corresponding module from the library to the file. If the module does not exist, TLIB displays a message and does not create a file. If the named file already exists, it is overwritten. -* Extract & TLIB copies the named module to the corresponding file name and then removes it from the library. -+ Replace TLIB replaces the named module with the corresponding file.

Examples

-------- These examples demonstrate some of the things you can do with TLIB: o To create a library named MYLIB.LIB with modules X.OBJ, Y.OBJ, and Z.OBJ, type "tlib mylib +x +y +z". o To create a library named MYLIB.LIB and get a listing in MYLIB.LST too, type "tlib mylib +x +y +z, mylib.lst". o To replace module X.OBJ with a new copy, add A.OBJ and delete Z.OBJ from MYLIB.LIB, type "tlib mylib -+x +a -z". o To create a new library (ALPHA) with modules A.OBJ, B.OBJ...G.OBJ using a response file: First create a text file, ALPHA.RSP, with @^+a.obj +b.obj +c.obj & +d.obj +e.obj +f.obj & +g.obj Then use the TLIB command, which produces a listing file named ALPHA.LST: "tlib alpha @alpha.rsp, alpha.lst". NOTE: You can't directly rename modules in a library. To rename a module, extract and remove it, rename the file just created, then add it back into the library. /**************************** END OF FILE ********************************/


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