CodeView: Difference between revisions

Revision as of 21:32, 8 January 2020

Revision as of 22:07, 8 January 2020

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{{Short description|Full-screen debugger for DOS by Microsoft}}

[[File:Dosbox 001.png|thumb|right|MS DOS's ''DEBUG'' command is line-oriented, whereas CodeView is full-screen oriented]]

{{Use dmy dates|date=January 2020|cs1-dates=y}}

'''CodeView''' is a standalone [[debugger]] created by [[David Norris (Microsoft)|David Norris]] at [[Microsoft]] in 1985 as part of its development toolset.<ref name=CV3x>{{cite magazine |magazine=[[WinWorld]]

[[File:Dosbox 001.png|thumb|right|MS DOS's ''[[DEBUG (DOS command)|DEBUG]]'' command is line-oriented, whereas CodeView is full-screen oriented]]

|title=WinWorld: CodeView 3.x

'''CodeView''' is a standalone [[debugger]] created by [[David Norris (Microsoft)|url=https://winworldpcDavid Norris]] at [[Microsoft]] in 1985 as part of its development toolset.com/product/codeview/3x}}</ref name="CV3x"/> It originally shipped with Microsoft C 4.0 and later. It also shipped with [[Visual Basic]] for [[MS-DOS]], [[Microsoft BasicBASIC PDS]], and a number of other Microsoft language products.<ref name="CV87"/>{{cite bookIt was one of the first debuggers on the [[DOS]] platform that was full-screen oriented, rather than line-oriented (as Microsoft's predecessors [[DEBUG (DOS command)|DEBUG]] and [[SYMDEB]] or [[Digital Research]]'s [[Symbolic Instruction Debugger|SID]]).

|title=[[Microsoft Macro Assembler]] 5.1 - Microsoft CodeView and Utilities

|date=1987

|quote=Document No. 4108-40010-500-R03-1287 |publisher=Microsoft Corporation}}</ref> It was one of the first debuggers on the MS-DOS platform that was full-screen oriented, rather than line oriented (like its predecessors [[DEBUG (DOS Command)|DEBUG.COM]] and [[#Symdeb|Symdeb]].

==Overview==

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* Watch window - a contextual display of variables by name.

* Locals window - a contextual display of variables local to the current function.

* Command window - user commands (using the same or similar syntax as DEBUG.COM and [[symdeb]]SYMDEB) could be entered here.

* Assembly window - the assembly (machine code) was displayed, allowing for single-stepping through functions.

* Register window - to visualize the 80x86 register contents, including segments, flags and the FPU (CodeView existed before MMX and other SIMD extensions).

* Output window - a window showing startup operations and debugging information relating to breakpoints,<ref name="CV87"/>{{rp|p. 157}} hardware breaks (interrupt 0 and 3), etc.

===featuresFeatures===

* 386 mode - 8086, 80286 and 80386 and later processors. 386 enhanced mode is activated by a menu option, allowing for 32-bit registers and disassembly.

* Monochrome monitor support - allows debugging on either a single color (CGA, EGA or VGA) monitor with page/memory swapping between the user application and the CodeView screen, or using a separate monochrome monitor. The monochrome monitor exists in memory address space 0xb0000, while the color monitor exists at 0xb8000 for text and 0xa0000 for graphics. Use of the monochrome monitor with its separate memory address space allows debugging graphics applications without affecting the display, as well as all text modes. Monochrome monitors are limited to 25 lines, whereas color monitors allow 25, 43 or 50 line mode, allowing for more information on the screen at the same time.

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CodeView handles all program models, including TINY, SMALL, COMPACT, MEDIUM, LARGE and HUGE, with TINY (DOS-based .COM files) having their symbolic debugger information stored in a separate file, with all of the other .EXE formats containing the symbolic information directly inside the executable. This often introduced a notable size increase, and it therefore became desirable for some developers to use #pragma switches within their C (and later C++) source code to prevent the majority of the application from having symbolic output, and instead limiting that output to only those portions which required it for current debugging.

CodeView version 3.x and 4.x introduced various transport layers, which removed some of the memory space limitations to this form of symbolic debugging. Typically the debugger runs in the lower 640KB memory space alongside the application being debugged, which greatly decreases the amount of memory available to the application being debugged. The transport layer allows only a stub to exist in main memory, while the bulk of the debugger code resides in EMS or XMS (memory above the 1MB1&nbsp;MB barrier, or outside of the normal 0KB0&nbsp;KB - 640KB640&nbsp;KB address space typically used by DOS programs). CodeView also came with a CVPACK command-line utility, which can reduce the size of the CodeView-generated information internally, while still retaining full symbolic access to data.

==Visual C++ support==

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==Symdeb==

<!-- Header linked by redirects -->

Another debugging product available from Microsoft in the mid-1980s was ''symdebSYMDEB''.<ref>{{cite webname="SYMDEB"/>

|url=https://www.pcjs.org/blog/2018/02/25

|title=A Short History of SYMDEB

|date=February 25, 2018 |author=Jeff Par |accessdate=May 19, 2019}}</ref>

It had over 30 commands, and was described by [[PC Magazine]] as "a step up from ''Debug''DEBUG.<ref name="PCW_1986"/>{{cite magazineCodeview in |magazineturn was described as "a fullscreen SYMDEB."<ref name=[[PC"PCMag_1986"/><ref World]]name="MSC4"/>

|date=October 14, 1986 |page=296

|title=SYMDEB: A step up from Debug

|url=https://books.google.com/books?id=nuXmVNll5JEC}}</ref> Codeview was described as "a fullscreen SYMDEB."<ref>{{cite magazine |magazine=[[PC Magazine]] |title=SYMDEB

|date=September 30, 1986 |page=38}}</ref><ref>{{cite web

|title=MS C 4.0 Documentation Added |website=OS2museum.com

|url=http://www.os2museum.com/wp/ms-c-4-0-documentation-added}}</ref>

==See also==

* [[Borland Turbo Debugger]]

* [[DEBUG (DOS command)|DEBUG]]

* [[Symbolic Instruction Debugger]] (SID, ZSID, SID86, GEMSID)<!-- link with possibilities -->

* [[Dynamic Debugging Tool]] (DDT)

* [[SoftICE]]

* [[Intel Memory Model]]

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==References==

{{Reflist}}|refs=

<ref name="CV3x">{{cite magazine |magazine=WinWorld |title=CodeView 3.x |url=https://winworldpc.com/product/codeview/3x}}</ref>

<ref name="CV87">{{cite book |title=Microsoft Macro Assembler 5.1 - Microsoft CodeView and Utilities |title-link=Microsoft Macro Assembler |date=1987 |id=Document No. 4108-40010-500-R03-1287 |publisher=[[Microsoft Corporation]] |page=157}}</ref>

<ref name="SYMDEB">{{cite web |url=https://www.pcjs.org/blog/2018/02/25 |work=PCjs Machines |title=A Short History of SYMDEB |date=2018-02-25 |author-first=Jeff |author-last=Par |access-date=2019-05-19}}</ref>

<ref name="PCW_1986">{{cite magazine |magazine=[[PC World]] |date=1986-10-14 |page=296 |title=SYMDEB: A step up from Debug |url=https://books.google.com/books?id=nuXmVNll5JEC}}</ref>

<ref name="PCMag_1986">{{cite magazine |magazine=[[PC Magazine]] |title=SYMDEB |date=1986-09-30 |page=38 |volume=5 |number=17 |issn=0888-8507 |publisher=[[Ziff Davis, Inc.]]}}</ref>

<ref name="MSC4">{{cite web |title=MS C 4.0 Documentation Added |website=OS2museum.com |url=http://www.os2museum.com/wp/ms-c-4-0-documentation-added}}</ref>

}}

==Further reading==

*{{cite book |author=Charles Petzold |authorlink=Charles Petzold |year=1990

* {{cite book |author-first=Charles |author-last=Petzold |author-link=Charles Petzold |date=1990 |title=Programming Windows: the Microsoft Guide to Writing Applications for Windows 3 |url=https://archive.org/details/programmingwindo0000petz |url-access=registration }}

* {{cite book |authorlinkpublisher=[[Microsoft Corporation ]] |yeardate=1993 |title=CodeView Debugger User's Guide}}

{{DEFAULTSORT:Codeview}}