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				https://sourceware.org/git/glibc.git
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	X32 has 32-bit long and pointer with 64-bit off_t. Since x32 psABI requires that pointers passed in registers must be zero-extended to 64bit, x32 can share many syscall interfaces with LP64. When a LP64 syscall with long and unsigned long int arguments is used for x32, these arguments must be properly extended to 64-bit. Otherwise if the upper 32 bits of the register have undefined value, such a syscall will be rejected by kernel. For syscalls implemented in assembly codes, 'U' is added to syscall signature key letters for unsigned long, which is zero-extended to 64-bit types. SYSCALL_ULONG_ARG_1 and SYSCALL_ULONG_ARG_2 are passed to syscall-template.S for the first and the second unsigned long int arguments if PSEUDOS_HAVE_ULONG_INDICES is defined. They are used by x32 to zero-extend 32-bit arguments to 64 bits. Tested on i386, x86-64 and x32 as well as with build-many-glibcs.py.
		
			
				
	
	
		
			296 lines
		
	
	
		
			8.6 KiB
		
	
	
	
		
			Bash
		
	
	
	
	
	
			
		
		
	
	
			296 lines
		
	
	
		
			8.6 KiB
		
	
	
	
		
			Bash
		
	
	
	
	
	
#!/bin/sh
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# Usage: make-syscalls.sh ../sysdeps/unix/common
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# Expects $sysdirs in environment.
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##############################################################################
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#
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# This script is used to process the syscall data encoded in the various
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# syscalls.list files to produce thin assembly syscall wrappers around the
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# appropriate OS syscall. See syscall-template.S for more details on the
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# actual wrapper.
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#
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# Syscall Signature Prefixes:
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#
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# E: errno and return value are not set by the call
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# V: errno is not set, but errno or zero (success) is returned from the call
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#
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# Syscall Signature Key Letters:
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#
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# a: unchecked address (e.g., 1st arg to mmap)
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# b: non-NULL buffer (e.g., 2nd arg to read; return value from mmap)
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# B: optionally-NULL buffer (e.g., 4th arg to getsockopt)
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# f: buffer of 2 ints (e.g., 4th arg to socketpair)
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# F: 3rd arg to fcntl
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# i: scalar (any signedness & size: int, long, long long, enum, whatever)
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# I: 3rd arg to ioctl
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# n: scalar buffer length (e.g., 3rd arg to read)
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# N: pointer to value/return scalar buffer length (e.g., 6th arg to recvfrom)
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# p: non-NULL pointer to typed object (e.g., any non-void* arg)
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# P: optionally-NULL pointer to typed object (e.g., 3rd argument to sigaction)
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# s: non-NULL string (e.g., 1st arg to open)
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# S: optionally-NULL string (e.g., 1st arg to acct)
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# U: unsigned long int (32-bit types are zero-extended to 64-bit types)
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# v: vararg scalar (e.g., optional 3rd arg to open)
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# V: byte-per-page vector (3rd arg to mincore)
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# W: wait status, optionally-NULL pointer to int (e.g., 2nd arg of wait4)
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#
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##############################################################################
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thisdir=$1; shift
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echo ''
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echo \#### DIRECTORY = $thisdir
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# Check each sysdep dir with higher priority than this one,
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# and remove from $calls all the functions found in other dirs.
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# Punt when we reach the directory defining these syscalls.
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sysdirs=`for dir in $sysdirs; do
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	 test $dir = $thisdir && break; echo $dir; done`
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echo \#### SYSDIRS = $sysdirs
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# Get the list of system calls for this directory.
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calls=`sed 's/#.*$//
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/^[ 	]*$/d' $thisdir/syscalls.list`
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calls=`echo "$calls" |
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while read file caller rest; do
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  # Remove each syscall that is implemented by a file in $dir.
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  # If a syscall specified a "caller", then only compile that syscall
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  # if the caller function is also implemented in this directory.
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  srcfile=-;
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  for dir in $sysdirs; do
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     { test -f $dir/$file.c && srcfile=$dir/$file.c; } ||
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     { test -f $dir/$file.S && srcfile=$dir/$file.S; } ||
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     { test x$caller != x- &&
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	{ { test -f $dir/$caller.c && srcfile=$dir/$caller.c; } ||
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	  { test -f $dir/$caller.S && srcfile=$dir/$caller.S; }; }; } && break;
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  done;
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  echo $file $srcfile $caller $rest;
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done`
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# Any calls left?
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test -n "$calls" || exit 0
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# This uses variables $weak, $strong, and $any_versioned.
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emit_weak_aliases()
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{
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  # A shortcoming in the current gas is that it will only allow one
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  # version-alias per symbol.  So we create new strong aliases as needed.
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  vcount=""
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  # We use the <shlib-compat.h> macros to generate the versioned aliases
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  # so that the version sets can be mapped to the configuration's
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  # minimum version set as per shlib-versions DEFAULT lines.  If an
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  # entry point is specified in the form NAME@VERSION:OBSOLETED, a
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  # SHLIB_COMPAT conditional is generated.
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  if [ $any_versioned = t ]; then
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    echo "	 echo '#include <shlib-compat.h>'; \\"
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  fi
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  for name in $weak; do
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    case $name in
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      *@@*)
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	base=`echo $name | sed 's/@@.*//'`
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	ver=`echo $name | sed 's/.*@@//;s/\./_/g'`
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	echo "	 echo '#if IS_IN (libc)'; \\"
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	if test -z "$vcount" ; then
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	  source=$strong
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	  vcount=1
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	else
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	  source="${strong}_${vcount}"
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	  vcount=`expr $vcount + 1`
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	  echo "	 echo 'strong_alias ($strong, $source)'; \\"
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	fi
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	echo "	 echo 'versioned_symbol (libc, $source, $base, $ver)'; \\"
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	echo "	 echo '#else'; \\"
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	echo "	 echo 'weak_alias ($strong, $base)'; \\"
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	echo "	 echo '#endif'; \\"
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	;;
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      *@*)
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	base=`echo $name | sed 's/@.*//'`
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	ver=`echo $name | sed 's/.*@//;s/\./_/g'`
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	case $ver in
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	  *:*)
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	    compat_ver=${ver#*:}
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	    ver=${ver%%:*}
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	    compat_cond=" && SHLIB_COMPAT (libc, $ver, $compat_ver)"
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	    ;;
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	  *)
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	    compat_cond=
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	    ;;
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	esac
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	echo "	 echo '#if defined SHARED && IS_IN (libc)$compat_cond'; \\"
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	if test -z "$vcount" ; then
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	  source=$strong
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	  vcount=1
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	else
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	  source="${strong}_${vcount}"
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	  vcount=`expr $vcount + 1`
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	  echo "	 echo 'strong_alias ($strong, $source)'; \\"
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	fi
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	echo "	 echo 'compat_symbol (libc, $source, $base, $ver)'; \\"
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	echo "	 echo '#endif'; \\"
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	;;
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      !*)
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	name=`echo $name | sed 's/.//'`
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	echo "	 echo 'strong_alias ($strong, $name)'; \\"
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	echo "	 echo 'hidden_def ($name)'; \\"
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	;;
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      *)
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	echo "	 echo 'weak_alias ($strong, $name)'; \\"
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	echo "	 echo 'hidden_weak ($name)'; \\"
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	;;
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    esac
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  done
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}
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# Emit rules to compile the syscalls remaining in $calls.
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echo "$calls" |
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while read file srcfile caller syscall args strong weak; do
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  case x"$syscall" in
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  x-) callnum=_ ;;
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  *)
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  # Figure out if $syscall is defined with a number in syscall.h.
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  callnum=-
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  eval `{ echo "#include <sysdep.h>";
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	echo "callnum=SYS_ify ($syscall)"; } |
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	  $asm_CPP -D__OPTIMIZE__ - |
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	  sed -n -e "/^callnum=.*$syscall/d" \
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		 -e "/^\(callnum=\)[ 	]*\(.*\)/s//\1'\2'/p"`
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  ;;
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  esac
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  noerrno=0
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  errval=0
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  case $args in
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  E*) noerrno=1; args=`echo $args | sed 's/E:\?//'`;;
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  V*) errval=1; args=`echo $args | sed 's/V:\?//'`;;
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  esac
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  # Derive the number of arguments from the argument signature
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  case $args in
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  [0-9]) nargs=$args;;
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  ?:) nargs=0;;
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  ?:?) nargs=1;;
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  ?:??) nargs=2;;
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  ?:???) nargs=3;;
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  ?:????) nargs=4;;
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  ?:?????) nargs=5;;
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  ?:??????) nargs=6;;
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  ?:???????) nargs=7;;
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  ?:????????) nargs=8;;
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  ?:?????????) nargs=9;;
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  esac
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  # Derive the unsigned long int arguments from the argument signature
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  ulong_arg_1=0
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  ulong_arg_2=0
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  ulong_count=0
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  for U in $(echo $args | sed -e "s/.*:/:/" | grep -ob U)
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  do
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    ulong_count=$(expr $ulong_count + 1)
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    ulong_arg=$(echo $U | sed -e "s/:U//")
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    case $ulong_count in
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    1)
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      ulong_arg_1=$ulong_arg
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      ;;
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    2)
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      ulong_arg_2=$ulong_arg
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      ;;
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    *)
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      echo >&2 "$0: Too many unsigned long int arguments for syscall ($strong $weak)"
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      exit 2
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    esac
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  done
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  # Make sure only the first syscall rule is used, if multiple dirs
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  # define the same syscall.
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  echo ''
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  echo "#### CALL=$file NUMBER=$callnum ARGS=$args SOURCE=$srcfile"
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  # If there are versioned aliases the entry is only generated for the
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  # shared library, unless it is a default version.
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  any_versioned=f
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  shared_only=f
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  case $weak in
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    *@@*) any_versioned=t ;;
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    *@*) any_versioned=t shared_only=t ;;
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  esac
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 case x$srcfile"$callnum" in
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 x--)
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  # Undefined callnum for an extra syscall.
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  if [ x$caller != x- ]; then
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    if [ $noerrno != 0 ]; then
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      echo >&2 "$0: no number for $fileno, no-error syscall ($strong $weak)"
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      exit 2
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    fi
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    echo "unix-stub-syscalls += $strong $weak"
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  fi
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  ;;
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 x*-) ;; ### Do nothing for undefined callnum
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 x-*)
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  echo "ifeq (,\$(filter $file,\$(unix-syscalls)))"
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  if test $shared_only = t; then
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    # The versioned symbols are only in the shared library.
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    echo "ifneq (,\$(filter .os,\$(object-suffixes)))"
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  fi
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  # Accumulate the list of syscall files for this directory.
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  echo "unix-syscalls += $file"
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  test x$caller = x- || echo "unix-extra-syscalls += $file"
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  # Emit a compilation rule for this syscall.
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  if test $shared_only = t; then
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    # The versioned symbols are only in the shared library.
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    echo "shared-only-routines += $file"
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    echo "\$(objpfx)${file}.os: \\"
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  else
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    object_suffixes='$(object-suffixes)'
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    echo "\
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\$(foreach p,\$(sysd-rules-targets),\
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\$(foreach o,${object_suffixes},\$(objpfx)\$(patsubst %,\$p,$file)\$o)): \\"
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  fi
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  echo "		\$(..)sysdeps/unix/make-syscalls.sh"
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  case x"$callnum" in
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  x_)
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  echo "\
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	\$(make-target-directory)
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	(echo '/* Dummy module requested by syscalls.list */'; \\"
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  ;;
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  x*)
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  echo "\
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	\$(make-target-directory)
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	(echo '#define SYSCALL_NAME $syscall'; \\
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	 echo '#define SYSCALL_NARGS $nargs'; \\
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	 echo '#define SYSCALL_ULONG_ARG_1 $ulong_arg_1'; \\
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	 echo '#define SYSCALL_ULONG_ARG_2 $ulong_arg_2'; \\
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	 echo '#define SYSCALL_SYMBOL $strong'; \\
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	 echo '#define SYSCALL_NOERRNO $noerrno'; \\
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	 echo '#define SYSCALL_ERRVAL $errval'; \\
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	 echo '#include <syscall-template.S>'; \\"
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  ;;
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  esac
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  # Append any weak aliases or versions defined for this syscall function.
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  emit_weak_aliases
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  # And finally, pipe this all into the compiler.
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  echo '	) | $(compile-syscall) '"\
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\$(foreach p,\$(patsubst %$file,%,\$(basename \$(@F))),\$(\$(p)CPPFLAGS))"
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  if test $shared_only = t; then
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    # The versioned symbols are only in the shared library.
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    echo endif
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  fi
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  echo endif
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 ;;
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 esac
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done
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