Xenix/386 alloca()

[Chip Salzenberg]

Several persons have requested alloca() for Xenix/386.  Okay, here it is.
Written in Microsoft assembler, it works with the Xenix/386 C compiler.

#! /bin/sh
# This is a shell archive.  Remove anything before this line, then unpack
# it by saving it into a file and typing "sh file".  To overwrite existing
# files, type "sh file -c".  You can also feed this as standard input via
# unshar, or by typing "sh <file", e.g..  If this archive is complete, you
# will see the following message at the end:
#		"End of shell archive."
# Contents:  Makefile alloca.s
# Wrapped by chip at ateng on Mon Mar 27 12:39:18 1989
PATH=/bin:/usr/bin:/usr/ucb ; export PATH
if test -f 'Makefile' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'Makefile'\"
else
echo shar: Extracting \"'Makefile'\" \(236 characters\)
sed "s/^X//" >'Makefile' <<'END_OF_FILE'
X# Makefile for alloca
X
XTARGET=Sliballoc.a
XASFLAGS=-Mx $(LISTING)
X
Xall:    $(TARGET)
X
Xclean:
X	rm -f *.o ?liballoc.a
X
XSliballoc.a: alloca.s
X	$(AS) $(ASFLAGS) -DMODEL_$(MODEL) -oalloca.o alloca.s
X	ar ru $@ alloca.o
X	rm alloca.o
X	ranlib $@
END_OF_FILE
if test 236 -ne `wc -c <'Makefile'`; then
    echo shar: \"'Makefile'\" unpacked with wrong size!
fi
# end of 'Makefile'
fi
if test -f 'alloca.s' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'alloca.s'\"
else
echo shar: Extracting \"'alloca.s'\" \(1075 characters\)
sed "s/^X//" >'alloca.s' <<'END_OF_FILE'
X; alloca.s
X; Allocate from the stack from a Microsoft C program.
X
X	TITLE   $alloca386
X
X	.386
X
X_DATA   SEGMENT  DWORD USE32 PUBLIC 'DATA'
X_DATA	ENDS
XCONST   SEGMENT  DWORD USE32 PUBLIC 'CONST'
XCONST	ENDS
X_BSS    SEGMENT  DWORD USE32 PUBLIC 'BSS'
X_BSS	ENDS
XDGROUP	GROUP	CONST, _BSS, _DATA
X
X_TEXT	SEGMENT  DWORD USE32 PUBLIC 'CODE'
X_TEXT   ENDS
X
X	ASSUME  CS: _TEXT, DS: DGROUP, SS: DGROUP, ES: DGROUP
X_TEXT      SEGMENT
X
X	PUBLIC  _alloca
X
X_alloca PROC NEAR
X
X;; Pop return address into edx and size into eax
X	pop     edx
X	pop     eax
X
X;; Make sure that eax is greater than zero, and is a multiple of four.
X	cmp     eax,0
X	jg      short pos
X	mov     eax,4
Xpos:
X	add     eax,3
X	and     eax,not 3
X
X;; Remember old stack pointer
X	mov     ecx,esp
X
X;; Figure new stack pointer, our return value.
X	sub     esp,eax
X	mov     eax,esp
X
X;; Copy the (hypothetical) register variables.
X	push    [ecx+8]
X	push    [ecx+4]
X	push    [ecx+0]
X
X;; Put something on the stack so that our caller can pop it off.
X	push    eax
X
X;; Return to the the caller.
X	jmp     edx
X
X_alloca ENDP
X
X_TEXT   ENDS
X
X	END
END_OF_FILE
if test 1075 -ne `wc -c <'alloca.s'`; then
    echo shar: \"'alloca.s'\" unpacked with wrong size!
fi
# end of 'alloca.s'
fi
echo shar: End of shell archive.
exit 0
-- 
Chip Salzenberg             <chip at ateng.com> or <uunet!ateng!chip>
A T Engineering             Me?  Speak for my company?  Surely you jest!
	  "It's no good.  They're tapping the lines."