CV.TXT File
Product Information for Microsoft(R) CodeView(TM), Version 4.01
Copyright (C) 1993, Microsoft Corporation. All rights reserved.
This document contains release notes for version 4.01 of Microsoft
CodeView for MS-DOS(R) and Microsoft Windows(TM) operating systems.
For more information on Microsoft CodeView, see Part 2, "The CodeView
Debugger," in the MASM Environment and Tools book.
Access to Function Code in Libraries
------------------------------------
The MASM CodeView debugger and linker do not guarantee that the
name of an .OBJ file is the same name the debugger or linker uses
to access the function code. To be certain of function access, use
the /f option when compiling. To avoid problems, do not put code in
include files. If you do put code into include files, specify the
function as inline.
Application I/O When Debugging Can Cause Screen Corruption
----------------------------------------------------------
If an application executes an I/O operation when the Flip/Swap
option is OFF, the screen may be corrupted.
.COM Files
----------
CodeView 4.01 does not show source code when debugging .COM files.
If you need to view source code, build your program as a small-model
.EXE for debugging purposes.
Debugging Applications that Use a Mouse
---------------------------------------
If you are using CV.EXE in a Windows MS-DOS session, and if you are
debugging an application that uses or alters the mouse, you must
specify the CodeView /M option to disable the mouse. This option is
necessary because the DPMI services provided by Windows 3.x in
enhanced mode do not allow for correctly saving and restoring the
mouse state.
Debugging Code that Uses 32-Bit Registers
-----------------------------------------
CodeView 4.01 does not support single-stepping through code that
uses 32-bit registers while a DPMI server is present. Windows 3.1
and 386-MAX are examples of DPMI servers. If you need to single-
step through 32-bit code, set breakpoints and use the F8 key for
single-stepping, or use an alternate debugger such as WDEB386
(available in the Microsoft Windows Software Development Kit).
Debugging Locally on an 80286
-----------------------------
To run CodeView with Windows and debug locally on an 80286 computer,
the following files must be installed on the host computer:
- CVW4.EXE (CodeView kernel)
- EEW0CXX.DLL (C++ expression evaluator)
- EEW0CAN.DLL (ANSI C expression evaluator)
- SHW0.DLL (symbol handler)
- EMW0W0.DLL (Windows-Windows execution model)
- TLW0LOC.DLL (local transport layer)
- TOOLHELP.DLL (Toolhelp)
Disable the Minimize On Use Option When Debugging
-------------------------------------------------
Running an application in CodeView for Windows can disable mouse and
keyboard control if the Minimize On Use option is set in the Windows
Program Manager. This behavior occurs if you run an application
using F5, restart from the Run menu, and begin to debug the
application. To recover from this problem, use CTRL+ALT+SysRq to
stop the application, issue the WKA command from within Codeview for
Windows, and choose Exit from the File menu to return to Windows.
MS-DOS Session Running in a Window Does Not Have Mouse Support
--------------------------------------------------------------
Running CodeView with the /2 option in an MS-DOS session window does
not have mouse support. If you want mouse support, change the
MS-DOS session to full screen.
Recovering from "Internal Debugger Error"
-----------------------------------------
If CodeView generates an "Internal debugger error," restart your
system.
Remote Debugging with CodeView
------------------------------
The required files needed on the host and the remote debugging
machine are operating-system dependent.
For running CodeView under MS-DOS, the following files must be
installed on the MS-DOS host. These files are needed for all
execution models:
- CV.EXE (CodeView kernel)
- SHD1.DLL (symbol handler)
- EED1CXX.DLL or EED1CAN.DLL (C++ expression evaluator or ANSI C
expression evaluator. Only one is needed, but EED1CXX.DLL
is required for programming with C++. EED1CXX.DLL is the only
expression evaluator provided with MASM.)
For remote debugging, you need to include the following statements in
the [RCVCOM] section of your TOOLS.INI file:
parameters: com1:9600
or specify the command line:
RCVCOM [-p com1:4800] [-r] [-?]
where [ ] represents an optional parameter. See page 370 in the
Environment and Tools book for a description of these parameters.
Remote debugging has three limitations:
- You must specify that the shell be exclusive.
- The recommended baud rate is 9600. If you experience any problems,
try decreasing the baud rate.
- The shell should be specified as full-screen.
Specify these settings in a .PIF file or in an MS-DOS session. Use
the Settings command to specify these settings in an MS-DOS shell.
If you install a CodeView DLL in a directory other than the one
in which Setup installs it, specify the path of the DLL with the
appropriate entry in your TOOLS.INI file. For example:
SYMBOLHANDLER:C:\CV4\SHD1.DLL
See also "Configuring CodeView with TOOLS.INI" on page 301, and
"Remote Debugging" on page 367, both in the Environment and Tools
book.
The following four sections describe additional files you need for
specific hosts and targets.
DOS-Hosted, DOS-Targeted Debugging: Host Computer
-------------------------------------------------
If you are not doing remote debugging, these additional files
must be installed on the host computer for DOS-hosted,
DOS-targeted debugging:
- EMD1D1.DLL (DOS host/DOS target execution model)
- TLD1LOC.DLL (local transport layer)
If you are doing remote debugging, these additional files must
be installed on the host computer for DOS-hosted, DOS-targeted
debugging:
- EMD1D1.DLL (DOS host/DOS target execution model)
- TLD1COM.DLL (COM port transport layer)
To specify these transport options, use the TRANSPORT statement
in your TOOLS.INI file. The path must be specified as follows:
TRANSPORT:C:\CV4\DLL\TLD1COM.DLL COM1:9600
If you do not specify COM#:baud_rate in the TRANSPORT statement,
CodeView prompts you for this information.
You must also add the Native entry to your TOOLS.INI file, giving
the execution model. The path is required:
NATIVE:C:\CV4\EMD1D1.DLL (for DOS host/DOS target execution model)
DOS-Hosted, DOS-Targeted Debugging: Target Computer
---------------------------------------------------
If you are doing remote DOS-hosted, DOS-targeted debugging, the
following file must be installed on the target computer:
- RCVCOM.EXE (remote CodeView for COM port)
DOS-Hosted, Windows-Targeted Debugging: Host Computer
-----------------------------------------------------
If you are doing remote debugging, these additional files must be
installed on the host computer for DOS-hosted, Windows-targeted
debugging:
- EMD1W0.DLL (DOS host/Windows target execution model)
- TLD1COM.DLL (COM port transport layer)
DOS-Hosted, Windows-Targeted Debugging: Target Computer
-------------------------------------------------------
If you are doing remote debugging, the following additional files
must be installed on the target computer for DOS-hosted, Windows-
targeted debugging:
- RCVWCOM.EXE (remote CodeView for COM port)
- DMW0.EXE (debug monitor on Windows target)
- TOOLHELP.DLL (Toolhelp)
Removing CodeView 3.07 from SDK Program Manager Group
-----------------------------------------------------
You can safely remove CodeView 3.07 from your SDK Program Manager
group to avoid confusion with the CodeView for Windows provided
with MASM or Microsoft C/C++.
Running CodeView on an 80286 Computer
-------------------------------------
To run CVW on an 80286 computer, delete CVW.EXE and rename CVW4.EXE as
CVW.EXE. Local debugging on an 80286 computer with an EGA adapter
requires a secondary monitor. Single-screen debugging is not supported.
Local debugging on an EGA system requires CodeView to be invoked with the
/2 command-line option.
Running Screen-Saver Programs While Debugging
---------------------------------------------
Do not run screen savers such as Idlewild or AfterDark while debugging;
their interactions with Windows can cause problems when debugging.
Setting the Scope of the Show Address Option in CodeView
--------------------------------------------------------
The printed documentation and Help incorrectly list the
syntax for setting the scope of the Show Address option in
the CodeView Command window (OL) as
OL[<scope>]
instead of
OL[[<scope>][+|-]].
The + and - switches can be used to turn other options on or
off, but will cause a syntax error if used to modify the scope
of the Show Address option.
You can choose several options for the OL command at the same time.
Each time you use the OL command, the scopes you specify will be
turned on and the scopes you don't specify will be turned off.
The OL command does not toggle the scopes. For example, the command
ollfg
turns on lexical, function, and global scope while it turns off module
and executable scope.
.STARTUP Code
-------------
When CodeView information is generated in mixed-mode assembly, it
is possible for CodeView .STARTUP code to be misplaced. For
example, from the source code
.MODEL SMALL, C
.STACK
.CODE
.STARTUP
mov ax,0
.EXIT
END
you would expect the following output:
1: .MODEL SMALL,C
2: .STACK
3: .CODE
4: .STARTUP
214F:0000 BA5021 MOV DX,2150
214F:0003 8EDA MOV DS,DX
214F:0005 8CD3 MOV BX,SS
214F:0007 2BDA SUB BX,DX
214F:0009 D1E3 SHL BX,1
214F:000B D1E3 SHL BX,1
214F:000D D1E3 SHL BX,1
214F:000F D1E3 SHL BX,1
214F:0011 FA CLI
214F:0012 8ED2 MOV SS,DX
214F:0014 03E3 ADD SP,BX
214F:0016 FB STI
5: mov ax,0
214F:0017 B80000 MOV AX,0000
6: .EXIT
However, you will see the following:
1: .MODEL SMALL,C
2: .STACK
3: .CODE
4: .STARTUP
5: mov ax,0
214F:0000 BA5021 MOV DX,2150
214F:0003 8EDA MOV DS,DX
214F:0005 8CD3 MOV BX,SS
214F:0007 2BDA SUB BX,DX
214F:0009 D1E3 SHL BX,1
214F:000B D1E3 SHL BX,1
214F:000D D1E3 SHL BX,1
214F:000F D1E3 SHL BX,1
214F:0011 FA CLI
214F:0012 8ED2 MOV SS,DX
214F:0014 03E3 ADD SP,BX
214F:0016 FB STI
214F:0017 B80000 MOV AX,0000
6: .EXIT
Note that line 5 has moved; however, the code will still run correctly.
Unloading DLLs When CodeView Terminates
---------------------------------------
You may have applications that use the LoadLibrary function to load
DLLs to be used by the application. When CVW.EXE terminates or
restarts such applications, Windows terminates the application without
unloading DLLs or decrementing the DLL usage count. As a result, DLLs
still exist in the system. To unload DLLs, you must either exit
Windows and restart, or use a utility.
Unsuccessful Connection to Remote Terminal
------------------------------------------
A remote monitor may appear to hang (the screen clears except for
the CodeView sign-on banner) when connecting to it from a host computer
that is running the debug kernel. In order to resolve this situation,
retry the connection when the debug kernel is not running on the
host computer.
===========================================================================
Microsoft, MS, MS-DOS, and CodeView are registered trademarks, and
Windows is a trademark of Microsoft Corporation. 386-MAX is a
trademark of Qualitas Corporation.
NOTE: Microsoft improves its languages documentation at the time of
reprinting, so some of the information in this file may already be
included in your manuals.
