sysdeps/unix/make-syscalls.sh - nest-cam/v366/glibc - Git at Google

 #! /bin/sh

 # Usage: make-syscalls.sh ../sysdeps/unix/common
 # Expects $sysdirs in environment.

 ##############################################################################

 # Syscall Signature Key Letters for BP Thunks:
 #
 # a: unchecked address (e.g., 1st arg to mmap)
 # b: non-NULL buffer (e.g., 2nd arg to read; return value from mmap)
 # B: optionally-NULL buffer (e.g., 4th arg to getsockopt)
 # f: buffer of 2 ints (e.g., 4th arg to socketpair)
 # F: 3rd arg to fcntl
 # i: scalar (any signedness & size: int, long, long long, enum, whatever)
 # I: 3rd arg to ioctl
 # n: scalar buffer length (e.g., 3rd arg to read)
 # N: pointer to value/return scalar buffer length (e.g., 6th arg to recvfrom)
 # p: non-NULL pointer to typed object (e.g., any non-void* arg)
 # P: optionally-NULL pointer to typed object (e.g., 2nd argument to gettimeofday)
 # s: non-NULL string (e.g., 1st arg to open)
 # S: optionally-NULL string (e.g., 1st arg to acct)
 # v: vararg scalar (e.g., optional 3rd arg to open)
 # V: byte-per-page vector (3rd arg to mincore)
 # W: wait status, optionally-NULL pointer to int (e.g., 2nd arg of wait4)

 ptr='[abBfFINpPsSWV]'	# all pointer keyletters
 int='[inv]'		# all scalar keyletters
 typ='[ifnNpP]'		# typed-arg keyletters: we capture type for use in thunk

 ##############################################################################

 thisdir=$1; shift

 echo ''
 echo \#### DIRECTORY = $thisdir
 # Check each sysdep dir with higher priority than this one,
 # and remove from $calls all the functions found in other dirs.
 # Punt when we reach the directory defining these syscalls.
 sysdirs=`for dir in $sysdirs; do
 	 test $dir = $thisdir && break; echo $dir; done`
 echo \#### SYSDIRS = $sysdirs

 # Get the list of system calls for this directory.
 calls=`sed 's/#.*$//
 /^[ 	]*$/d' $thisdir/syscalls.list`

 calls=`echo "$calls" |
 while read file caller rest; do
   # Remove each syscall that is implemented by a file in $dir.
   # If a syscall specified a "caller", then only compile that syscall
   # if the caller function is also implemented in this directory.
   srcfile=-;
   for dir in $sysdirs; do
      { test -f $dir/$file.c && srcfile=$dir/$file.c; } ||
      { test -f $dir/$file.S && srcfile=$dir/$file.S; } ||
      { test -f $dir/$file.s && srcfile=$dir/$file.s; } ||
      { test x$caller != x- &&
 	{ { test -f $dir/$caller.c && srcfile=$dir/$caller.c; } ||
 	  { test -f $dir/$caller.S && srcfile=$dir/$caller.S; } ||
 	  { test -f $dir/$caller.s && srcfile=$dir/$caller.s; }; }; } && break;
   done;
   echo $file $srcfile $caller $rest;
 done`

 # Any calls left?
 test -n "$calls" || exit 0

 # Emit rules to compile the syscalls remaining in $calls.
 echo "$calls" |
 while read file srcfile caller syscall args strong weak; do

   case x"$syscall" in
   x-) callnum=_ ;;
   *)
   # Figure out if $syscall is defined with a number in syscall.h.
   callnum=-
   eval `{ echo "#include <sysdep.h>";
 	echo "callnum=SYS_ify ($syscall)"; } |
 	  $asm_CPP -D__OPTIMIZE__ - |
 	  sed -n -e "/^callnum=.*$syscall/d" \
 		 -e "/^\(callnum=\)[ 	]*\(.*\)/s//\1'\2'/p"`
   ;;
   esac

   cancellable=0
   noerrno=0
   errval=0
   case $args in
   C*) cancellable=1; args=`echo $args | sed 's/C:\?//'`;;
   E*) noerrno=1; args=`echo $args | sed 's/E:\?//'`;;
   V*) errval=1; args=`echo $args | sed 's/V:\?//'`;;
   esac

   # Derive the number of arguments from the argument signature
   case $args in
   [0-9]) nargs=$args;;
   ?:) nargs=0;;
   ?:?) nargs=1;;
   ?:??) nargs=2;;
   ?:???) nargs=3;;
   ?:????) nargs=4;;
   ?:?????) nargs=5;;
   ?:??????) nargs=6;;
   ?:???????) nargs=7;;
   ?:????????) nargs=8;;
   ?:?????????) nargs=9;;
   esac

   # Make sure only the first syscall rule is used, if multiple dirs
   # define the same syscall.
   echo ''
   echo "#### CALL=$file NUMBER=$callnum ARGS=$args SOURCE=$srcfile"

  case x$srcfile"$callnum" in
  x--)
   # Undefined callnum for an extra syscall.
   if [ x$caller != x- ]; then
     if [ $noerrno != 0 ]; then
       echo >&2 "$0: no number for $fileno, no-error syscall ($strong $weak)"
       exit 2
     fi
     echo "unix-stub-syscalls += $strong $weak"
   fi
   ;;
  x*-) ;; ### Do nothing for undefined callnum
  x-*)
   echo "ifeq (,\$(filter $file,\$(unix-syscalls)))"

   case $weak in
   *@*)
     # The versioned symbols are only in the shared library.
     echo "ifneq (,\$(filter .os,\$(object-suffixes)))"
     ;;
   esac
   # Accumulate the list of syscall files for this directory.
   echo "unix-syscalls += $file"
   test x$caller = x- || echo "unix-extra-syscalls += $file"

   # Emit a compilation rule for this syscall.
   case $weak in
   *@*)
     # The versioned symbols are only in the shared library.
     echo "\
 shared-only-routines += $file
 \$(objpfx)${file}.os: \\"
     ;;
   *)
     echo "\
 \$(foreach p,\$(sysd-rules-targets),\
 \$(foreach o,\$(object-suffixes),\$(objpfx)\$(patsubst %,\$p,$file)\$o)): \\"
     ;;
   esac

   echo "		\$(..)sysdeps/unix/make-syscalls.sh"
   case x"$callnum" in
   x_)
   echo "\
 	\$(make-target-directory)
 	(echo '/* Dummy module requested by syscalls.list */'; \\"
   ;;
   x*)
   echo "\
 	\$(make-target-directory)
 	(echo '#define SYSCALL_NAME $syscall'; \\
 	 echo '#define SYSCALL_NARGS $nargs'; \\
 	 echo '#define SYSCALL_SYMBOL $strong'; \\"
   [ $cancellable = 0 ] || echo "\
 	 echo '#define SYSCALL_CANCELLABLE 1'; \\"
   [ $noerrno = 0 ] || echo "\
 	 echo '#define SYSCALL_NOERRNO 1'; \\"
   [ $errval = 0 ] || echo "\
 	 echo '#define SYSCALL_ERRVAL 1'; \\"
   echo "\
 	 echo '#include <syscall-template.S>'; \\"
   ;;
   esac

   # Append any weak aliases or versions defined for this syscall function.

   # A shortcoming in the current gas is that it will only allow one
   # version-alias per symbol.  So we create new strong aliases as needed.
   vcount=""

   for name in $weak; do
     case $name in
       *@@*)
 	base=`echo $name | sed 's/@@.*//'`
 	ver=`echo $name | sed 's/.*@@//'`
 	if test -z "$vcount" ; then
 	  source=$strong
 	  vcount=1
 	else
 	  source="${strong}_${vcount}"
 	  vcount=`expr $vcount + 1`
 	  echo "	 echo 'strong_alias ($strong, $source)'; \\"
 	fi
 	echo "	 echo 'default_symbol_version($source, $base, $ver)'; \\"
 	;;
       *@*)
 	base=`echo $name | sed 's/@.*//'`
 	ver=`echo $name | sed 's/.*@//'`
 	if test -z "$vcount" ; then
 	  source=$strong
 	  vcount=1
 	else
 	  source="${strong}_${vcount}"
 	  vcount=`expr $vcount + 1`
 	  echo "	 echo 'strong_alias ($strong, $source)'; \\"
 	fi
 	echo "	 echo 'symbol_version ($source, $base, $ver)'; \\"
 	;;
       !*)
 	name=`echo $name | sed 's/.//'`
 	echo "	 echo 'strong_alias ($strong, $name)'; \\"
 	echo "	 echo 'libc_hidden_def ($name)'; \\"
 	;;
       *)
 	echo "	 echo 'weak_alias ($strong, $name)'; \\"
 	echo "	 echo 'libc_hidden_weak ($name)'; \\"
 	;;
     esac
   done

   # And finally, pipe this all into the compiler.
   echo '	) | $(compile-syscall) '"\
 \$(foreach p,\$(patsubst %$file,%,\$(basename \$(@F))),\$(\$(p)CPPFLAGS))"

   case $weak in
   *@*)
     # The versioned symbols are only in the shared library.
     echo endif
     ;;
   esac

   echo endif
  ;;
  esac

   case x"$callnum",$srcfile,$args in
   x[_-],-,* | x*,*.[sS],*V*) ;;
   x*,-,*$ptr* | x*,*.[sS],*$ptr*)

     nv_weak=`for name in $weak; do
 		case $name in
 		*@*) ;;
 		*) echo $name;;
 	        esac; done`

     # choose the name with the fewest leading underscores, preferably none
     set `echo $strong $nv_weak |tr '@ \t' ' \n\n' |sort -r`
     callname=$1

     # convert signature string to individual numbered arg names
     # e.g., i:ipbN -> i0 i1 p2 b3 N4
     set `echo $args |
 	sed -e 's/^\(.\):\(.*\)/\2 <\10>/' \
 	    -e 's/^\([^ ]\)\(.*\)/\2 <\11>/' \
 	    -e 's/^\([^ ]\)\(.*\)/\2 <\12>/' \
 	    -e 's/^\([^ ]\)\(.*\)/\2 <\13>/' \
 	    -e 's/^\([^ ]\)\(.*\)/\2 <\14>/' \
 	    -e 's/^\([^ ]\)\(.*\)/\2 <\15>/' \
 	    -e 's/^\([^ ]\)\(.*\)/\2 <\16>/' \
 	    -e 's/^\([^ ]\)\(.*\)/\2 <\17>/' \
 	    -e 's/^\([^ ]\)\(.*\)/\2 <\18>/' \
 	    -e 's/^\([^ ]\)\(.*\)/\2 <\19>/'`
     rtn=$1; shift
     args=$*
     arglist=`echo $* |sed 's/ /, /g'`

     # The best way to understand what's going on here is to examine
     # the output in BUILDDIR/sysd-syscalls.

     # generate makefile envelope & rule head
     echo "ifeq (,\$(filter $file,\$(bp-thunks)))"
     echo "bp-thunks += $file"
     echo "\$(objpfx)\$(bppfx)$file.ob: \$(common-objpfx)s-proto-bp.d"

     # generate macro head
     echo "	(echo '#define $callname(`echo $arglist | \
 	    sed -e 's/[<>]//g'`) `echo $rtn | \
 	    sed -e 's/<\('$typ'0\)>/\1v;/g' \
 		-e 's/<\(b0\)>/x0; extern char \1v;/g'` \\'; \\"

     # generate extern decls of dummy variables for each arg
     echo "	 echo '`echo $args | \
 	    sed -e 's/<\('$typ'[1-9]\)>/extern \1, \1v;/g' \
 		-e 's/<\([abBFIsSV][1-9]\)>/extern char \1v;/g' \
 		-e 's/<\([Wv][1-9]\)>/extern int \1v;/g'` \\'; \\"

     # generate bounded-pointer thunk declarator
     echo "	 echo '`echo $rtn | \
 	    sed -e 's/<\('$ptr'0\)>/__typeof (\1v) *__bounded/g' \
 		-e 's/<\('$int'0\)>/__typeof (\1v)/g'` BP_SYM ($strong) (`echo $arglist | \
 	    sed -e 's/<\('$ptr'[1-9]\)>/__typeof (\1v) *__bounded \1a/g' \
 		-e 's/<\('$int'[1-9]\)>/__typeof (\1v) \1a/g'`) { \\'; \\"

     # generate extern primitive syscall declaration
     echo "	 echo '  extern `echo $rtn | \
 	    sed -e 's/<\('$ptr'0\)>/__typeof (\1v) *__unbounded/g' \
 		-e 's/<\('$int'0\)>/__typeof (\1v)/g'` ($callname) (`echo $arglist | \
 	    sed -e 's/<\('$ptr'[1-9]\)>/__typeof (\1v) *__unbounded/g' \
 		-e 's/<\('$int'[1-9]\)>/__typeof (\1v)/g'`); \\'; \\"

     # generate call the primtive system call, optionally wrapping bounds
     # around the result if the signature's return keyletter is `b'.
     echo "	 echo '  return `echo $rtn |
 	    sed -e 's/<b0>/BOUNDED_N (/' \
 		-e 's/<.0>//'`($callname) (`echo $arglist | \
 	    sed -e 's/<\(a[1-9]\)>/__ptrvalue (\1a)/g' \
 		-e 's/<\(n[1-9]\)>, <\(V[1-9]\)>/\1a, CHECK_N_PAGES (\2a, \1a)/g' \
 		-e 's/<\(b[1-9]\)>, <\(n[1-9]\)>/CHECK_N (\1a, \2a), \2a/g' \
 		-e 's/<\(b[1-9]\)>, <\(N[1-9]\)>/CHECK_N (\1a, *CHECK_1 (\2a)), __ptrvalue (\2a)/g' \
 		-e 's/<\(B[1-9]\)>, <\(n[1-9]\)>/CHECK_N_NULL_OK (\1a, \2a), \2a/g' \
 		-e 's/<\(B[1-9]\)>, <\(N[1-9]\)>/CHECK_N_NULL_OK (\1a, *CHECK_1 (\2a)), __ptrvalue (\2a)/g' \
 		-e 's/<\(f[1-9]\)>/CHECK_N (\1a, 2)/g' \
 		-e 's/<\(i[1-9]\)>, <\(F[1-9]\)>/\1a, CHECK_FCNTL (\2a, \1a)/g' \
 		-e 's/<\(i[1-9]\)>, <\(I[1-9]\)>/\1a, CHECK_IOCTL (\2a, \1a)/g' \
 		-e 's/<\(p[1-9]\)>/CHECK_1 (\1a)/g' \
 		-e 's/<\([PW][1-9]\)>/CHECK_1_NULL_OK (\1a)/g' \
 		-e 's/<\(s[1-9]\)>/CHECK_STRING (\1a)/g' \
 		-e 's/<\(S[1-9]\)>/CHECK_STRING_NULL_OK (\1a)/g' \
 		-e 's/<\([ivn][1-9]\)>/\1a/g'`)`echo $rtn $args |
 	    sed -e 's/<b0>.*<\(n[1-9]\)>.*/, \1a)/' \
 		-e 's/<.0>.*//'`; \\'; \\"

     echo "	 echo '} \\'; \\"

     echo "	 echo 'libc_hidden_def (BP_SYM ($strong)) \\'; \\"

     # generate thunk aliases
     for name in $nv_weak; do
       echo "	 echo 'weak_alias (BP_SYM ($strong), BP_SYM ($name)) \\'; \\"
       echo "	 echo 'libc_hidden_weak (BP_SYM ($name)) \\'; \\"
     done

     # wrap up
     echo "\
 	 echo ''; \\
 	 echo '#include <bp-thunks.h>'; \\
 	) | \$(COMPILE.c) -x c -o \$@ -"
 ### Use this for debugging intermediate output:
 ### 	) >\$(@:.ob=.c)
 ### 	\$(subst -c,-E,\$(COMPILE.c)) -o \$(@:.ob=.ib) \$(@:.ob=.c)
 ### 	\$(COMPILE.c) -x cpp-output -o \$@ \$(@:.ob=.ib)"
     echo endif
     ;;
   esac

 done
	#! /bin/sh

	# Usage: make-syscalls.sh ../sysdeps/unix/common
	# Expects $sysdirs in environment.

	##############################################################################

	# Syscall Signature Key Letters for BP Thunks:
	#
	# a: unchecked address (e.g., 1st arg to mmap)
	# b: non-NULL buffer (e.g., 2nd arg to read; return value from mmap)
	# B: optionally-NULL buffer (e.g., 4th arg to getsockopt)
	# f: buffer of 2 ints (e.g., 4th arg to socketpair)
	# F: 3rd arg to fcntl
	# i: scalar (any signedness & size: int, long, long long, enum, whatever)
	# I: 3rd arg to ioctl
	# n: scalar buffer length (e.g., 3rd arg to read)
	# N: pointer to value/return scalar buffer length (e.g., 6th arg to recvfrom)
	# p: non-NULL pointer to typed object (e.g., any non-void* arg)
	# P: optionally-NULL pointer to typed object (e.g., 2nd argument to gettimeofday)
	# s: non-NULL string (e.g., 1st arg to open)
	# S: optionally-NULL string (e.g., 1st arg to acct)
	# v: vararg scalar (e.g., optional 3rd arg to open)
	# V: byte-per-page vector (3rd arg to mincore)
	# W: wait status, optionally-NULL pointer to int (e.g., 2nd arg of wait4)

	ptr='[abBfFINpPsSWV]' # all pointer keyletters
	int='[inv]' # all scalar keyletters
	typ='[ifnNpP]' # typed-arg keyletters: we capture type for use in thunk

	##############################################################################

	thisdir=$1; shift

	echo ''
	echo \#### DIRECTORY = $thisdir
	# Check each sysdep dir with higher priority than this one,
	# and remove from $calls all the functions found in other dirs.
	# Punt when we reach the directory defining these syscalls.
	sysdirs=`for dir in $sysdirs; do
	test $dir = $thisdir && break; echo $dir; done`
	echo \#### SYSDIRS = $sysdirs

	# Get the list of system calls for this directory.
	calls=`sed 's/#.*$//
	/^[ ]*$/d' $thisdir/syscalls.list`

	calls=`echo "$calls" \|
	while read file caller rest; do
	# Remove each syscall that is implemented by a file in $dir.
	# If a syscall specified a "caller", then only compile that syscall
	# if the caller function is also implemented in this directory.
	srcfile=-;
	for dir in $sysdirs; do
	{ test -f $dir/$file.c && srcfile=$dir/$file.c; } \|\|
	{ test -f $dir/$file.S && srcfile=$dir/$file.S; } \|\|
	{ test -f $dir/$file.s && srcfile=$dir/$file.s; } \|\|
	{ test x$caller != x- &&
	{ { test -f $dir/$caller.c && srcfile=$dir/$caller.c; } \|\|
	{ test -f $dir/$caller.S && srcfile=$dir/$caller.S; } \|\|
	{ test -f $dir/$caller.s && srcfile=$dir/$caller.s; }; }; } && break;
	done;
	echo $file $srcfile $caller $rest;
	done`

	# Any calls left?
	test -n "$calls" \|\| exit 0

	# Emit rules to compile the syscalls remaining in $calls.
	echo "$calls" \|
	while read file srcfile caller syscall args strong weak; do

	case x"$syscall" in
	x-) callnum=_ ;;
	*)
	# Figure out if $syscall is defined with a number in syscall.h.
	callnum=-
	eval `{ echo "#include <sysdep.h>";
	echo "callnum=SYS_ify ($syscall)"; } \|
	$asm_CPP -D__OPTIMIZE__ - \|
	sed -n -e "/^callnum=.*$syscall/d" \
	-e "/^\(callnum=\)[ ]\(.\)/s//\1'\2'/p"`
	;;
	esac

	cancellable=0
	noerrno=0
	errval=0
	case $args in
	C*) cancellable=1; args=`echo $args \| sed 's/C:\?//'`;;
	E*) noerrno=1; args=`echo $args \| sed 's/E:\?//'`;;
	V*) errval=1; args=`echo $args \| sed 's/V:\?//'`;;
	esac

	# Derive the number of arguments from the argument signature
	case $args in
	[0-9]) nargs=$args;;
	?:) nargs=0;;
	?:?) nargs=1;;
	?:??) nargs=2;;
	?:???) nargs=3;;
	?:????) nargs=4;;
	?:?????) nargs=5;;
	?:??????) nargs=6;;
	?:???????) nargs=7;;
	?:????????) nargs=8;;
	?:?????????) nargs=9;;
	esac

	# Make sure only the first syscall rule is used, if multiple dirs
	# define the same syscall.
	echo ''
	echo "#### CALL=$file NUMBER=$callnum ARGS=$args SOURCE=$srcfile"

	case x$srcfile"$callnum" in
	x--)
	# Undefined callnum for an extra syscall.
	if [ x$caller != x- ]; then
	if [ $noerrno != 0 ]; then
	echo >&2 "$0: no number for $fileno, no-error syscall ($strong $weak)"
	exit 2
	fi
	echo "unix-stub-syscalls += $strong $weak"
	fi
	;;
	x*-) ;; ### Do nothing for undefined callnum
	x-*)
	echo "ifeq (,\$(filter $file,\$(unix-syscalls)))"

	case $weak in
	@)
	# The versioned symbols are only in the shared library.
	echo "ifneq (,\$(filter .os,\$(object-suffixes)))"
	;;
	esac
	# Accumulate the list of syscall files for this directory.
	echo "unix-syscalls += $file"
	test x$caller = x- \|\| echo "unix-extra-syscalls += $file"

	# Emit a compilation rule for this syscall.
	case $weak in
	@)
	# The versioned symbols are only in the shared library.
	echo "\
	shared-only-routines += $file
	\$(objpfx)${file}.os: \\"
	;;
	*)
	echo "\
	\$(foreach p,\$(sysd-rules-targets),\
	\$(foreach o,\$(object-suffixes),\$(objpfx)\$(patsubst %,\$p,$file)\$o)): \\"
	;;
	esac

	echo " \$(..)sysdeps/unix/make-syscalls.sh"
	case x"$callnum" in
	x_)
	echo "\
	\$(make-target-directory)
	(echo '/* Dummy module requested by syscalls.list */'; \\"
	;;
	x*)
	echo "\
	\$(make-target-directory)
	(echo '#define SYSCALL_NAME $syscall'; \\
	echo '#define SYSCALL_NARGS $nargs'; \\
	echo '#define SYSCALL_SYMBOL $strong'; \\"
	[ $cancellable = 0 ] \|\| echo "\
	echo '#define SYSCALL_CANCELLABLE 1'; \\"
	[ $noerrno = 0 ] \|\| echo "\
	echo '#define SYSCALL_NOERRNO 1'; \\"
	[ $errval = 0 ] \|\| echo "\
	echo '#define SYSCALL_ERRVAL 1'; \\"
	echo "\
	echo '#include <syscall-template.S>'; \\"
	;;
	esac

	# Append any weak aliases or versions defined for this syscall function.

	# A shortcoming in the current gas is that it will only allow one
	# version-alias per symbol. So we create new strong aliases as needed.
	vcount=""

	for name in $weak; do
	case $name in
	@@)
	base=`echo $name \| sed 's/@@.*//'`
	ver=`echo $name \| sed 's/.*@@//'`
	if test -z "$vcount" ; then
	source=$strong
	vcount=1
	else
	source="${strong}_${vcount}"
	vcount=`expr $vcount + 1`
	echo " echo 'strong_alias ($strong, $source)'; \\"
	fi
	echo " echo 'default_symbol_version($source, $base, $ver)'; \\"
	;;
	@)
	base=`echo $name \| sed 's/@.*//'`
	ver=`echo $name \| sed 's/.*@//'`
	if test -z "$vcount" ; then
	source=$strong
	vcount=1
	else
	source="${strong}_${vcount}"
	vcount=`expr $vcount + 1`
	echo " echo 'strong_alias ($strong, $source)'; \\"
	fi
	echo " echo 'symbol_version ($source, $base, $ver)'; \\"
	;;
	!*)
	name=`echo $name \| sed 's/.//'`
	echo " echo 'strong_alias ($strong, $name)'; \\"
	echo " echo 'libc_hidden_def ($name)'; \\"
	;;
	*)
	echo " echo 'weak_alias ($strong, $name)'; \\"
	echo " echo 'libc_hidden_weak ($name)'; \\"
	;;
	esac
	done

	# And finally, pipe this all into the compiler.
	echo ' ) \| $(compile-syscall) '"\
	\$(foreach p,\$(patsubst %$file,%,\$(basename \$(@F))),\$(\$(p)CPPFLAGS))"

	case $weak in
	@)
	# The versioned symbols are only in the shared library.
	echo endif
	;;
	esac

	echo endif
	;;
	esac

	case x"$callnum",$srcfile,$args in
	x[_-],-,* \| x,.[sS],V) ;;
	x,-,$ptr* \| x,.[sS],$ptr)

	nv_weak=`for name in $weak; do
	case $name in
	@) ;;
	*) echo $name;;
	esac; done`

	# choose the name with the fewest leading underscores, preferably none
	set `echo $strong $nv_weak \|tr '@ \t' ' \n\n' \|sort -r`
	callname=$1

	# convert signature string to individual numbered arg names
	# e.g., i:ipbN -> i0 i1 p2 b3 N4
	set `echo $args \|
	sed -e 's/^\(.\):\(.*\)/\2 <\10>/' \
	-e 's/^\([^ ]\)\(.*\)/\2 <\11>/' \
	-e 's/^\([^ ]\)\(.*\)/\2 <\12>/' \
	-e 's/^\([^ ]\)\(.*\)/\2 <\13>/' \
	-e 's/^\([^ ]\)\(.*\)/\2 <\14>/' \
	-e 's/^\([^ ]\)\(.*\)/\2 <\15>/' \
	-e 's/^\([^ ]\)\(.*\)/\2 <\16>/' \
	-e 's/^\([^ ]\)\(.*\)/\2 <\17>/' \
	-e 's/^\([^ ]\)\(.*\)/\2 <\18>/' \
	-e 's/^\([^ ]\)\(.*\)/\2 <\19>/'`
	rtn=$1; shift
	args=$*
	arglist=`echo $* \|sed 's/ /, /g'`

	# The best way to understand what's going on here is to examine
	# the output in BUILDDIR/sysd-syscalls.

	# generate makefile envelope & rule head
	echo "ifeq (,\$(filter $file,\$(bp-thunks)))"
	echo "bp-thunks += $file"
	echo "\$(objpfx)\$(bppfx)$file.ob: \$(common-objpfx)s-proto-bp.d"

	# generate macro head
	echo " (echo '#define $callname(`echo $arglist \| \
	sed -e 's/[<>]//g'`) `echo $rtn \| \
	sed -e 's/<\('$typ'0\)>/\1v;/g' \
	-e 's/<\(b0\)>/x0; extern char \1v;/g'` \\'; \\"

	# generate extern decls of dummy variables for each arg
	echo " echo '`echo $args \| \
	sed -e 's/<\('$typ'[1-9]\)>/extern \1, \1v;/g' \
	-e 's/<\([abBFIsSV][1-9]\)>/extern char \1v;/g' \
	-e 's/<\([Wv][1-9]\)>/extern int \1v;/g'` \\'; \\"

	# generate bounded-pointer thunk declarator
	echo " echo '`echo $rtn \| \
	sed -e 's/<\('$ptr'0\)>/__typeof (\1v) *__bounded/g' \
	-e 's/<\('$int'0\)>/__typeof (\1v)/g'` BP_SYM ($strong) (`echo $arglist \| \
	sed -e 's/<\('$ptr'[1-9]\)>/__typeof (\1v) *__bounded \1a/g' \
	-e 's/<\('$int'[1-9]\)>/__typeof (\1v) \1a/g'`) { \\'; \\"

	# generate extern primitive syscall declaration
	echo " echo ' extern `echo $rtn \| \
	sed -e 's/<\('$ptr'0\)>/__typeof (\1v) *__unbounded/g' \
	-e 's/<\('$int'0\)>/__typeof (\1v)/g'` ($callname) (`echo $arglist \| \
	sed -e 's/<\('$ptr'[1-9]\)>/__typeof (\1v) *__unbounded/g' \
	-e 's/<\('$int'[1-9]\)>/__typeof (\1v)/g'`); \\'; \\"

	# generate call the primtive system call, optionally wrapping bounds
	# around the result if the signature's return keyletter is `b'.
	echo " echo ' return `echo $rtn \|
	sed -e 's/<b0>/BOUNDED_N (/' \
	-e 's/<.0>//'`($callname) (`echo $arglist \| \
	sed -e 's/<\(a[1-9]\)>/__ptrvalue (\1a)/g' \
	-e 's/<\(n[1-9]\)>, <\(V[1-9]\)>/\1a, CHECK_N_PAGES (\2a, \1a)/g' \
	-e 's/<\(b[1-9]\)>, <\(n[1-9]\)>/CHECK_N (\1a, \2a), \2a/g' \
	-e 's/<\(b[1-9]\)>, <\(N[1-9]\)>/CHECK_N (\1a, *CHECK_1 (\2a)), __ptrvalue (\2a)/g' \
	-e 's/<\(B[1-9]\)>, <\(n[1-9]\)>/CHECK_N_NULL_OK (\1a, \2a), \2a/g' \
	-e 's/<\(B[1-9]\)>, <\(N[1-9]\)>/CHECK_N_NULL_OK (\1a, *CHECK_1 (\2a)), __ptrvalue (\2a)/g' \
	-e 's/<\(f[1-9]\)>/CHECK_N (\1a, 2)/g' \
	-e 's/<\(i[1-9]\)>, <\(F[1-9]\)>/\1a, CHECK_FCNTL (\2a, \1a)/g' \
	-e 's/<\(i[1-9]\)>, <\(I[1-9]\)>/\1a, CHECK_IOCTL (\2a, \1a)/g' \
	-e 's/<\(p[1-9]\)>/CHECK_1 (\1a)/g' \
	-e 's/<\([PW][1-9]\)>/CHECK_1_NULL_OK (\1a)/g' \
	-e 's/<\(s[1-9]\)>/CHECK_STRING (\1a)/g' \
	-e 's/<\(S[1-9]\)>/CHECK_STRING_NULL_OK (\1a)/g' \
	-e 's/<\([ivn][1-9]\)>/\1a/g'`)`echo $rtn $args \|
	sed -e 's/<b0>.<\(n[1-9]\)>./, \1a)/' \
	-e 's/<.0>.*//'`; \\'; \\"

	echo " echo '} \\'; \\"

	echo " echo 'libc_hidden_def (BP_SYM ($strong)) \\'; \\"

	# generate thunk aliases
	for name in $nv_weak; do
	echo " echo 'weak_alias (BP_SYM ($strong), BP_SYM ($name)) \\'; \\"
	echo " echo 'libc_hidden_weak (BP_SYM ($name)) \\'; \\"
	done

	# wrap up
	echo "\
	echo ''; \\
	echo '#include <bp-thunks.h>'; \\
	) \| \$(COMPILE.c) -x c -o \$@ -"
	### Use this for debugging intermediate output:
	### ) >\$(@:.ob=.c)
	### \$(subst -c,-E,\$(COMPILE.c)) -o \$(@:.ob=.ib) \$(@:.ob=.c)
	### \$(COMPILE.c) -x cpp-output -o \$@ \$(@:.ob=.ib)"
	echo endif
	;;
	esac

	done