crt0fp.asm

[随书类]Dos6.0源代码

	page	,132
	title	crt0fp - floating point not loaded trap
;***
;crt0fp.asm - floating point not loaded trap
;
;	Copyright (c) 1986-1988, Microsoft Corporation, All Rights Reserved
;
;Purpose:
;	To trap certain cases where certain necessary floating-point
;	software is not loaded.  Two specific cases are when 87.LIB
;	is linked in but no coprocessor is present, and when floating
;	point i/o conversions are done, but no floating-point variables
;	or expressions are used in the program.
;
;*******************************************************************************

?DF=	1			; this is special for c startup
include	version.inc
.xlist
include	cmacros.inc
.list

createSeg _TEXT, code,	word,	public, CODE,	<>


sBegin	code
assumes	cs,code

externNP _amsg_exit

page
;***
;_fptrap - trap for missing floating-point software
;
;Purpose:
;	Catches these cases of incomplete f.p. software linked into a program.
;
;	(1) 87.LIB chosen, but no coprocessor present;
;	    (i.e., emulator not linked)
;
;	(2) "%e", "%f", and "%g" i/o conversion formats specified, but
;	    not all conversion software has been linked in, because the
;	    program did not use any floating-point variables or expressions.
;
;Entry:
;	None.
;
;Exit:
;	None.
;
;Uses:
;	AX.
;
;Exceptions:
;	Transfers control to _amsg_exit which ...
; 	- Writes error message to standard error:  "floating point not loaded";
;	- Terminates the program by calling _exit().
;*******************************************************************************

labelNP <PUBLIC,_fptrap>


	mov	ax,2		; issue floating point not loaded
	jmp	_amsg_exit	;   and die

sEnd	code

	end