Article: Q40784
Product(s): Microsoft Programming Utilities
Version(s): 2.2,3.0,3.11,3.12,3.14,3.5,4.0,4.01,4.05,4.1
Operating System(s):
Keyword(s): kb16bitonly
Last Modified: 26-JUN-2001
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The information in this article applies to:
- Microsoft CodeView for MS-DOS, versions 2.2, 3.0, 3.11, 3.14, 4.0, 4.01, 4.05, 4.1
- Microsoft CodeView for OS/2, versions 2.2, 3.0, 3.11, 3.12, 3.5
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Using the Microsoft Macro Assembler (MASM), it is possible to
associate various segments into a group; DGROUP is an example of this
technique. Grouped data or stack segments do not affect CodeView but
CodeView does not recognize grouped code segments. The program will
run correctly under CodeView but none of the CodeView functions will
be available on the second and subsequent segments in the code group.
The sample code below illustrates this behavior. Once the program
executes into the _TEXTB segment, all CodeView functionality is lost.
You cannot set any breakpoints or single step through the _TEXTB code.
Any attempt to single trace into _TEXTB will result in CodeView
running all the code in _TEXTB as if you had specified a go or a step
Sample Code
-----------
; Assembler options needed: /Zi
DOSSEG
_TEXT GROUP _TEXTA, _TEXTB ; Code group _TEXT
_DATA SEGMENT WORD PUBLIC 'DATA'
msg DB "Hello, world.", 13, 10, "$"
_DATA ENDS
_TEXTA SEGMENT WORD PUBLIC 'CODE' ; First code segment - this
ASSUME cs:_TEXT,ds:_DATA ; code may be traced as
start: mov ax, _DATA ; expected.
mov ds, ax
call FAR PTR SayHi
mov ax, 4C00h
int 21h
_TEXTA ENDS
_TEXTB SEGMENT WORD PUBLIC 'CODE' ; You cannot trace through
SayHi PROC ; this code.
mov ah, 9h
mov dx, OFFSET msg
int 21h
ret
SayHi ENDP
_TEXTB ENDS
END start
Additional query words: kbinf 2.20 3.00 3.50 4.10
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Keywords : kb16bitonly
Technology : kbAudDeveloper kbCodeView kbZNotKeyword3 kbCodeView220DOS kbCodeView300DOS kbCodeView311DOS kbCodeView314DOS kbCodeView400DOS kbCodeView401DOS kbCodeView405DOS kbCodeView410DOS kbCodeView220OS2 kbCodeView300OS2 kbCodeView311OS2 kbCodeView312OS2 kbCodeView350OS2
Version : :2.2,3.0,3.11,3.12,3.14,3.5,4.0,4.01,4.05,4.1
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