sysdeps/unix/make-syscalls.sh

   1 #!/bin/sh
   2
   3 # Usage: make-syscalls.sh ../sysdeps/unix/common
   4 # Expects $sysdirs in environment.
   5
   6 ##############################################################################
   7 #
   8 # This script is used to process the syscall data encoded in the various
   9 # syscalls.list files to produce thin assembly syscall wrappers around the
  10 # appropriate OS syscall. See syscall-template.S for more details on the
  11 # actual wrapper.
  12 #
  13 # Syscall Signature Prefixes:
  14 #
  15 # E: errno and return value are not set by the call
  16 # V: errno is not set, but errno or zero (success) is returned from the call
  17 #
  18 # Syscall Signature Key Letters:
  19 #
  20 # a: unchecked address (e.g., 1st arg to mmap)
  21 # b: non-NULL buffer (e.g., 2nd arg to read; return value from mmap)
  22 # B: optionally-NULL buffer (e.g., 4th arg to getsockopt)
  23 # f: buffer of 2 ints (e.g., 4th arg to socketpair)
  24 # F: 3rd arg to fcntl
  25 # i: scalar (any signedness & size: int, long, long long, enum, whatever)
  26 # I: 3rd arg to ioctl
  27 # n: scalar buffer length (e.g., 3rd arg to read)
  28 # N: pointer to value/return scalar buffer length (e.g., 6th arg to recvfrom)
  29 # p: non-NULL pointer to typed object (e.g., any non-void* arg)
  30 # P: optionally-NULL pointer to typed object (e.g., 3rd argument to sigaction)
  31 # s: non-NULL string (e.g., 1st arg to open)
  32 # S: optionally-NULL string (e.g., 1st arg to acct)
  33 # U: unsigned long int (32-bit types are zero-extended to 64-bit types)
  34 # v: vararg scalar (e.g., optional 3rd arg to open)
  35 # V: byte-per-page vector (3rd arg to mincore)
  36 # W: wait status, optionally-NULL pointer to int (e.g., 2nd arg of wait4)
  37 #
  38
  39 ##############################################################################
  40
  41 thisdir=$1; shift
  42
  43 echo ''
  44 echo \#### DIRECTORY = $thisdir
  45 # Check each sysdep dir with higher priority than this one,
  46 # and remove from $calls all the functions found in other dirs.
  47 # Punt when we reach the directory defining these syscalls.
  48 sysdirs=`for dir in $sysdirs; do
  49          test $dir = $thisdir && break; echo $dir; done`
  50 echo \#### SYSDIRS = $sysdirs
  51
  52 # Get the list of system calls for this directory.
  53 calls=`sed 's/#.*$//
  54 /^[     ]*$/d' $thisdir/syscalls.list`
  55
  56 calls=`echo "$calls" |
  57 while read file caller rest; do
  58   # Remove each syscall that is implemented by a file in $dir.
  59   # If a syscall specified a "caller", then only compile that syscall
  60   # if the caller function is also implemented in this directory.
  61   srcfile=-;
  62   for dir in $sysdirs; do
  63      { test -f $dir/$file.c && srcfile=$dir/$file.c; } ||
  64      { test -f $dir/$file.S && srcfile=$dir/$file.S; } ||
  65      { test x$caller != x- &&
  66         { { test -f $dir/$caller.c && srcfile=$dir/$caller.c; } ||
  67           { test -f $dir/$caller.S && srcfile=$dir/$caller.S; }; }; } && break;
  68   done;
  69   echo $file $srcfile $caller $rest;
  70 done`
  71
  72 # Any calls left?
  73 test -n "$calls" || exit 0
  74
  75 # This uses variables $weak, $strong, and $any_versioned.
  76 emit_weak_aliases()
  77 {
  78   # A shortcoming in the current gas is that it will only allow one
  79   # version-alias per symbol.  So we create new strong aliases as needed.
  80   vcount=""
  81
  82   # We use the <shlib-compat.h> macros to generate the versioned aliases
  83   # so that the version sets can be mapped to the configuration's
  84   # minimum version set as per shlib-versions DEFAULT lines.  If an
  85   # entry point is specified in the form NAME@VERSION:OBSOLETED, a
  86   # SHLIB_COMPAT conditional is generated.
  87   if [ $any_versioned = t ]; then
  88     echo "       echo '#include <shlib-compat.h>'; \\"
  89   fi
  90
  91   for name in $weak; do
  92     case $name in
  93       *@@*)
  94         base=`echo $name | sed 's/@@.*//'`
  95         ver=`echo $name | sed 's/.*@@//;s/\./_/g'`
  96         echo "   echo '#if IS_IN (libc)'; \\"
  97         if test -z "$vcount" ; then
  98           source=$strong
  99           vcount=1
 100         else
 101           source="${strong}_${vcount}"
 102           vcount=`expr $vcount + 1`
 103           echo "         echo 'strong_alias ($strong, $source)'; \\"
 104         fi
 105         echo "   echo 'versioned_symbol (libc, $source, $base, $ver)'; \\"
 106         echo "   echo '#else'; \\"
 107         echo "   echo 'weak_alias ($strong, $base)'; \\"
 108         echo "   echo '#endif'; \\"
 109         ;;
 110       *@*)
 111         base=`echo $name | sed 's/@.*//'`
 112         ver=`echo $name | sed 's/.*@//;s/\./_/g'`
 113         case $ver in
 114           *:*)
 115             compat_ver=${ver#*:}
 116             ver=${ver%%:*}
 117             compat_cond=" && SHLIB_COMPAT (libc, $ver, $compat_ver)"
 118             ;;
 119           *)
 120             compat_cond=
 121             ;;
 122         esac
 123         echo "   echo '#if defined SHARED && IS_IN (libc)$compat_cond'; \\"
 124         if test -z "$vcount" ; then
 125           source=$strong
 126           vcount=1
 127         else
 128           source="${strong}_${vcount}"
 129           vcount=`expr $vcount + 1`
 130           echo "         echo 'strong_alias ($strong, $source)'; \\"
 131         fi
 132         echo "   echo 'compat_symbol (libc, $source, $base, $ver)'; \\"
 133         echo "   echo '#endif'; \\"
 134         ;;
 135       !*)
 136         name=`echo $name | sed 's/.//'`
 137         echo "   echo 'strong_alias ($strong, $name)'; \\"
 138         echo "   echo 'hidden_def ($name)'; \\"
 139         ;;
 140       *)
 141         echo "   echo 'weak_alias ($strong, $name)'; \\"
 142         echo "   echo 'hidden_weak ($name)'; \\"
 143         ;;
 144     esac
 145   done
 146 }
 147
 148
 149 # Emit rules to compile the syscalls remaining in $calls.
 150 echo "$calls" |
 151 while read file srcfile caller syscall args strong weak; do
 152
 153   case x"$syscall" in
 154   x-) callnum=_ ;;
 155   *)
 156   # Figure out if $syscall is defined with a number in syscall.h.
 157   callnum=-
 158   eval `{ echo "#include <sysdep.h>";
 159         echo "callnum=SYS_ify ($syscall)"; } |
 160           $asm_CPP -D__OPTIMIZE__ - |
 161           sed -n -e "/^callnum=.*$syscall/d" \
 162                  -e "/^\(callnum=\)[    ]*\(.*\)/s//\1'\2'/p"`
 163   ;;
 164   esac
 165
 166   noerrno=0
 167   errval=0
 168   case $args in
 169   E*) noerrno=1; args=`echo $args | sed 's/E:\?//'`;;
 170   V*) errval=1; args=`echo $args | sed 's/V:\?//'`;;
 171   esac
 172
 173   # Derive the number of arguments from the argument signature
 174   case $args in
 175   [0-9]) nargs=$args;;
 176   ?:) nargs=0;;
 177   ?:?) nargs=1;;
 178   ?:??) nargs=2;;
 179   ?:???) nargs=3;;
 180   ?:????) nargs=4;;
 181   ?:?????) nargs=5;;
 182   ?:??????) nargs=6;;
 183   ?:???????) nargs=7;;
 184   ?:????????) nargs=8;;
 185   ?:?????????) nargs=9;;
 186   esac
 187
 188   # Derive the unsigned long int arguments from the argument signature
 189   ulong_arg_1=0
 190   ulong_arg_2=0
 191   ulong_count=0
 192   for U in $(echo $args | sed -e "s/.*:/:/" | grep -ob U)
 193   do
 194     ulong_count=$(expr $ulong_count + 1)
 195     ulong_arg=$(echo $U | sed -e "s/:U//")
 196     case $ulong_count in
 197     1)
 198       ulong_arg_1=$ulong_arg
 199       ;;
 200     2)
 201       ulong_arg_2=$ulong_arg
 202       ;;
 203     *)
 204       echo >&2 "$0: Too many unsigned long int arguments for syscall ($strong $weak)"
 205       exit 2
 206     esac
 207   done
 208
 209   # Make sure only the first syscall rule is used, if multiple dirs
 210   # define the same syscall.
 211   echo ''
 212   echo "#### CALL=$file NUMBER=$callnum ARGS=$args SOURCE=$srcfile"
 213
 214   # If there are versioned aliases the entry is only generated for the
 215   # shared library, unless it is a default version.
 216   any_versioned=f
 217   shared_only=f
 218   case $weak in
 219     *@@*) any_versioned=t ;;
 220     *@*) any_versioned=t shared_only=t ;;
 221   esac
 222
 223  case x$srcfile"$callnum" in
 224  x--)
 225   # Undefined callnum for an extra syscall.
 226   if [ x$caller != x- ]; then
 227     if [ $noerrno != 0 ]; then
 228       echo >&2 "$0: no number for $fileno, no-error syscall ($strong $weak)"
 229       exit 2
 230     fi
 231     echo "unix-stub-syscalls += $strong $weak"
 232   fi
 233   ;;
 234  x*-) ;; ### Do nothing for undefined callnum
 235  x-*)
 236   echo "ifeq (,\$(filter $file,\$(unix-syscalls)))"
 237
 238   if test $shared_only = t; then
 239     # The versioned symbols are only in the shared library.
 240     echo "ifneq (,\$(filter .os,\$(object-suffixes)))"
 241   fi
 242   # Accumulate the list of syscall files for this directory.
 243   echo "unix-syscalls += $file"
 244   test x$caller = x- || echo "unix-extra-syscalls += $file"
 245
 246   # Emit a compilation rule for this syscall.
 247   if test $shared_only = t; then
 248     # The versioned symbols are only in the shared library.
 249     echo "shared-only-routines += $file"
 250     echo "\$(objpfx)${file}.os: \\"
 251   else
 252     object_suffixes='$(object-suffixes)'
 253     echo "\
 254 \$(foreach p,\$(sysd-rules-targets),\
 255 \$(foreach o,${object_suffixes},\$(objpfx)\$(patsubst %,\$p,$file)\$o)): \\"
 256   fi
 257
 258   echo "                \$(..)sysdeps/unix/make-syscalls.sh"
 259   case x"$callnum" in
 260   x_)
 261   echo "\
 262         \$(make-target-directory)
 263         (echo '/* Dummy module requested by syscalls.list */'; \\"
 264   ;;
 265   x*)
 266   echo "\
 267         \$(make-target-directory)
 268         (echo '#define SYSCALL_NAME $syscall'; \\
 269          echo '#define SYSCALL_NARGS $nargs'; \\
 270          echo '#define SYSCALL_ULONG_ARG_1 $ulong_arg_1'; \\
 271          echo '#define SYSCALL_ULONG_ARG_2 $ulong_arg_2'; \\
 272          echo '#define SYSCALL_SYMBOL $strong'; \\
 273          echo '#define SYSCALL_NOERRNO $noerrno'; \\
 274          echo '#define SYSCALL_ERRVAL $errval'; \\
 275          echo '#include <syscall-template.S>'; \\"
 276   ;;
 277   esac
 278
 279   # Append any weak aliases or versions defined for this syscall function.
 280   emit_weak_aliases
 281
 282   # And finally, pipe this all into the compiler.
 283   echo '        ) | $(compile-syscall) '"\
 284 \$(foreach p,\$(patsubst %$file,%,\$(basename \$(@F))),\$(\$(p)CPPFLAGS))"
 285
 286   if test $shared_only = t; then
 287     # The versioned symbols are only in the shared library.
 288     echo endif
 289   fi
 290
 291   echo endif
 292  ;;
 293  esac
 294
 295 done