DOCERR: Guide to Programming LIBENTRY.ASM
ID: Q69894
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The information in this article applies to:
-
Microsoft Windows Software Development Kit (SDK) versions 3.0, 3.1
SYMPTOMS
Pages 20-22 and 20-23 of the "Microsoft Windows Software Development
Kit Guide to Programming" for versions 3.0 and 3.1 include incorrect
code for the Windows dynamic-link library (DLL) entry routine,
LIBENTRY.ASM.
RESOLUTION
The following is the correct code:
PAGE,132
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
; LIBENTRY.ASM
;
; Windows dynamic-link library entry routine
;
; This module generates a code segment called INIT_TEXT.
; It initializes the local heap if one exists and then calls
; the C routine LibMain which should have the form:
; BOOL FAR PASCAL LibMain(HANDLE hInstance,
; WORD wDataSeg,
; WORD cbHeap,
; LPSTR lpszCmdLine);
;
; The result of the call to LibMain is returned to Windows.
; The C routine should return TRUE if it completes initialization
; successfully, FALSE if some error occurs.
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
include cmacros.inc
externFP <LibMain> ; the C routine to be called
createSeg INIT_TEXT, INIT_TEXT, BYTE, PUBLIC, CODE
sBegin INIT_TEXT
assumes CS,INIT_TEXT
?PLM=0 ; 'C'naming
externA <_acrtused> ; ensures that Win DLL startup code
; is linked
?PLM=1 ; 'PASCAL' naming
externFP <LocalInit> ; Windows heap init routine
cProc LibEntry, <PUBLIC,FAR> ; entry point into DLL
cBegin
push di ; handle of the module instance
push ds ; library data segment
push cx ; heap size
push es ; command line segment
push si ; command line offset
; if we have some heap then initialize it
jcxz callc ; jump if no heap specified
; call the Windows function LocalInit to set up the heap
; LocalInit((LPSTR)start, WORD cbHeap);
xor ax,ax
cCall LocalInit <ds, ax, cx>
or ax,ax ; did it do it ok ?
jz error ; quit if it failed
; invoke the C routine to do any special initialization
callc:
call LibMain ; invoke the 'C' routine
; (result in AX)
jmp short exit ; LibMain is responsible for
; stack clean up
error:
pop si ; clean up stack on a LocalInit error
pop es
pop cx
pop ds
pop di
exit:
cEnd
sEnd INIT_TEXT
end LibEntry
Additional query words:
3.00 3.10 docerr
Keywords : kb16bitonly
Version : WINDOWS:3.0,3.1
Platform : WINDOWS
Issue type :