Hardware Reference
In-Depth Information
where the file list consists of the name of the cross-reference file
generated by MASM followed by the name of the readable (ASCII format)
cross-reference file.
Library managers
A library manager allows the programmer to gather a number of object code
files (i.e. those with an OBJ extension) into a single library file (having an
LIB extension). This file will generally be used in the production of several
different programs and the object code modules collected by the library manager
may be special modules created by the programmer or modules taken from an
existing library. An optional library list usually can also be created by the library
manager.
The value of building a library is that the routines needed within a program
can be very easily linked into an executable object code file. Routines taken from
the library can be used to construct further libraries or combined, as necessary,
into executable programs by the linker.
The Microsoft library manager (LIB) is invoked by a command of the form:
LIB <library name><file list>
where the file list contains the names of the object code modules (each preceded
bya'
' and separated by a comma) which are to be added to the library. As an
example, the command line:
LIB graphics +fill, +shape
will add the object code modules fill.obj and shape.obj to the graphics library.
Symbolic debuggers
A symbolic debugger is an item of utility software that is designed to facilitate
interactive testing and debugging of programs. As a minimum, a debugger
should provide the user with commands which can be used to:
•
Examine and modify the contents of memory.
•
Examine and modify the content of the CPU registers.
•
Run a program (starting at a given address) with breakpoints at which
execution may be halted to permit examination of the CPU registers.
•
Single-step a program (starting at a given address) with a register dump at
the completion of each instruction.
•
Disassemble a block of memory into assembly language mnemonics.
•
Relocate a given block of memory.
•
Initialize a given block of memory with specified data.
•
Load or save blocks of memory from/to disk.
The debugger provided with the MS-DOS operating system (DEBUG) can
be used for simple debugging (see Chapter 3); however, the Microsoft macro
assembler provides a much enhanced debugger which is known as CodeView.
This package is a powerful window-oriented software tool which allows the
