FreeBSD/Linux Kernel Cross Reference
sys/kern/vnode_if.sh

     #!/bin/sh -
     #
     # Copyright (c) 1992, 1993
     #       The Regents of the University of California.  All rights reserved.
     #
     # Redistribution and use in source and binary forms, with or without
     # modification, are permitted provided that the following conditions
     # are met:
     # 1. Redistributions of source code must retain the above copyright
    #    notice, this list of conditions and the following disclaimer.
    # 2. Redistributions in binary form must reproduce the above copyright
    #    notice, this list of conditions and the following disclaimer in the
    #    documentation and/or other materials provided with the distribution.
    # 3. All advertising materials mentioning features or use of this software
    #    must display the following acknowledgement:
    #       This product includes software developed by the University of
    #       California, Berkeley and its contributors.
    # 4. Neither the name of the University nor the names of its contributors
    #    may be used to endorse or promote products derived from this software
    #    without specific prior written permission.
    #
    # THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
    # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    # ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
    # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
    # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
    # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    # SUCH DAMAGE.
    #
    #       @(#)vnode_if.sh 8.1 (Berkeley) 6/10/93
    # $FreeBSD: src/sys/kern/vnode_if.sh,v 1.9.4.2 1999/09/05 08:15:48 peter Exp $
    #
    
    # Script to produce VFS front-end sugar.
    #
    # usage: vnode_if.sh srcfile
    #       (where srcfile is currently /sys/kern/vnode_if.src)
    #
    # These awk scripts are not particularly well written, specifically they
    # don't use arrays well and figure out the same information repeatedly.
    # Please rewrite them if you actually understand how to use awk.  Note,
    # they use nawk extensions and gawk's toupper.
    
    if [ $# -ne 1 ] ; then
            echo 'usage: vnode_if.sh srcfile'
            exit 1
    fi
    
    # Name of the source file.
    SRC=$1
    
    # Names of the created files.
    CFILE=vnode_if.c
    HEADER=vnode_if.h
    
    # Awk program (must support nawk extensions and gawk's "toupper")
    # Use "awk" at Berkeley, "gawk" elsewhere.
    AWK=awk
    
    # Print out header information for vnode_if.h.
    cat << END_OF_LEADING_COMMENT > $HEADER
    /*
     * This file is produced automatically.
     * Do not modify anything in here by hand.
     *
     * Created from @(#)vnode_if.sh 8.1 (Berkeley) 6/10/93
     */
    
    extern struct vnodeop_desc vop_default_desc;
    END_OF_LEADING_COMMENT
    
    # Awk script to take vnode_if.src and turn it into vnode_if.h.
    $AWK '
            NF == 0 || $0 ~ "^#" {
                    next;
            }
            {
                    # Get the function name.
                    name = $1;
                    uname = toupper(name);
    
                    # Get the function arguments.
                    for (c1 = 0;; ++c1) {
                            if (getline <= 0)
                                    exit
                            if ($0 ~ "^};")
                                    break;
                            a[c1] = $0;
                    }
    
                    # Print out the vop_F_args structure.
                    printf("struct %s_args {\n\tstruct vnodeop_desc *a_desc;\n",
                        name);
                    for (c2 = 0; c2 < c1; ++c2) {
                            c3 = split(a[c2], t);
                           printf("\t");
                           if (t[2] ~ "WILLRELE")
                                   c4 = 3;
                           else 
                                   c4 = 2;
                           for (; c4 < c3; ++c4)
                                   printf("%s ", t[c4]);
                           beg = match(t[c3], "[^*]");
                           printf("%sa_%s\n",
                               substr(t[c4], 0, beg - 1), substr(t[c4], beg));
                   }
                   printf("};\n");
   
                   # Print out extern declaration.
                   printf("extern struct vnodeop_desc %s_desc;\n", name);
   
                   # Print out prototype.
                   printf("static int %s __P((\n", uname);
                   sep = ",\n";
                   for (c2 = 0; c2 < c1; ++c2) {
                           if (c2 == c1 - 1)
                                   sep = "));\n";
                           c3 = split(a[c2], t);
                           printf("\t");
                           if (t[2] ~ "WILLRELE")
                                   c4 = 3;
                           else
                                   c4 = 2;
                           for (; c4 < c3; ++c4)
                                   printf("%s ", t[c4]);
                           beg = match(t[c3], "[^*]");
                           end = match(t[c3], ";");
                           printf("%s%s%s",
                               substr(t[c4], 0, beg - 1),
                               substr(t[c4], beg, end - beg), sep);
                   }
   
                   # Print out inline struct.
                   printf("static __inline int %s(", uname);
                   sep = ", ";
                   for (c2 = 0; c2 < c1; ++c2) {
                           if (c2 == c1 - 1)
                                   sep = ")\n";
                           c3 = split(a[c2], t);
                           beg = match(t[c3], "[^*]");
                           end = match(t[c3], ";");
                           printf("%s%s", substr(t[c3], beg, end - beg), sep);
                   }
                   for (c2 = 0; c2 < c1; ++c2) {
                           c3 = split(a[c2], t);
                           printf("\t");
                           if (t[2] ~ "WILLRELE")
                                   c4 = 3;
                           else
                                   c4 = 2;
                           for (; c4 < c3; ++c4)
                                   printf("%s ", t[c4]);
                           beg = match(t[c3], "[^*]");
                           printf("%s%s\n",
                               substr(t[c4], 0, beg - 1), substr(t[c4], beg));
                   }
                   printf("{\n\tstruct %s_args a;\n\n", name);
                   printf("\ta.a_desc = VDESC(%s);\n", name);
                   for (c2 = 0; c2 < c1; ++c2) {
                           c3 = split(a[c2], t);
                           printf("\t");
                           beg = match(t[c3], "[^*]");
                           end = match(t[c3], ";");
                           printf("a.a_%s = %s\n",
                               substr(t[c3], beg, end - beg), substr(t[c3], beg));
                   }
                   c1 = split(a[0], t);
                   beg = match(t[c1], "[^*]");
                   end = match(t[c1], ";");
                   printf("\treturn (VCALL(%s, VOFFSET(%s), &a));\n}\n",
                       substr(t[c1], beg, end - beg), name);
           }' < $SRC >> $HEADER
   
   # Print out header information for vnode_if.c.
   cat << END_OF_LEADING_COMMENT > $CFILE
   /*
    * This file is produced automatically.
    * Do not modify anything in here by hand.
    *
    * Created from @(#)vnode_if.sh 8.1 (Berkeley) 6/10/93
    */
   
   #include <sys/param.h>
   #include <sys/mount.h>
   #include <sys/vnode.h>
   
   struct vnodeop_desc vop_default_desc = {
           0,
           "default",
           0,
           NULL,
           VDESC_NO_OFFSET,
           VDESC_NO_OFFSET,
           VDESC_NO_OFFSET,
           VDESC_NO_OFFSET,
           NULL,
   };
   
   END_OF_LEADING_COMMENT
   
   # Awk script to take vnode_if.src and turn it into vnode_if.c.
   $AWK 'function kill_surrounding_ws (s) {
                   sub (/^[ \t]*/, "", s);
                   sub (/[ \t]*$/, "", s);
                   return s;
           }
   
           function read_args() {
                   numargs = 0;
                   while (getline ln) {
                           if (ln ~ /}/) {
                                   break;
                           };
           
                           # Delete comments, if any.
                           gsub (/\/\*.*\*\//, "", ln);
                           
                           # Delete leading/trailing space.
                           ln = kill_surrounding_ws(ln);
           
                           # Pick off direction.
                           if (1 == sub(/^INOUT[ \t]+/, "", ln))
                                   dir = "INOUT";
                           else if (1 == sub(/^IN[ \t]+/, "", ln))
                                   dir = "IN";
                           else if (1 == sub(/^OUT[ \t]+/, "", ln))
                                   dir = "OUT";
                           else
                                   bail("No IN/OUT direction for \"" ln "\".");
   
                           # check for "WILLRELE"
                           if (1 == sub(/^WILLRELE[ \t]+/, "", ln)) {
                                   rele = "WILLRELE";
                           } else {
                                   rele = "WONTRELE";
                           };
           
                           # kill trailing ;
                           if (1 != sub (/;$/, "", ln)) {
                                   bail("Missing end-of-line ; in \"" ln "\".");
                           };
           
                           # pick off variable name
                           if (!(i = match(ln, /[A-Za-z0-9_]+$/))) {
                                   bail("Missing var name \"a_foo\" in \"" ln "\".");
                           };
                           arg = substr (ln, i);
                           # Want to <<substr(ln, i) = "";>>, but nawk cannot.
                           # Hack around this.
                           ln = substr(ln, 1, i-1);
           
                           # what is left must be type
                           # (put clean it up some)
                           type = ln;
                           gsub (/[ \t]+/, " ", type);   # condense whitespace
                           type = kill_surrounding_ws(type);
           
                           # (boy this was easier in Perl)
           
                           numargs++;
                           dirs[numargs] = dir;
                           reles[numargs] = rele;
                           types[numargs] = type;
                           args[numargs] = arg;
                   };
           }
   
           function generate_operation_vp_offsets() {
                   printf ("static int %s_vp_offsets[] = {\n", name);
                   # as a side effect, figure out the releflags
                   releflags = "";
                   vpnum = 0;
                   for (i=1; i<=numargs; i++) {
                           if (types[i] == "struct vnode *") {
                                   printf ("\tVOPARG_OFFSETOF(struct %s_args,a_%s),\n",
                                           name, args[i]);
                                   if (reles[i] == "WILLRELE") {
                                           releflags = releflags "|VDESC_VP" vpnum "_WILLRELE";
                                   };
                                   vpnum++;
                           };
                   };
                   sub (/^\|/, "", releflags);
                   print "\tVDESC_NO_OFFSET";
                   print "};";
           }
           
           function find_arg_with_type (type) {
                   for (i=1; i<=numargs; i++) {
                           if (types[i] == type) {
                                   return "VOPARG_OFFSETOF(struct " name "_args,a_" args[i] ")";
                           };
                   };
                   return "VDESC_NO_OFFSET";
           }
           
           function generate_operation_desc() {
                   printf ("struct vnodeop_desc %s_desc = {\n", name);
                   # offset
                   printf ("\t0,\n");
                   # printable name
                   printf ("\t\"%s\",\n", name);
                   # flags
                   vppwillrele = "";
                   for (i=1; i<=numargs; i++) {
                           if (types[i] == "struct vnode **" &&
                                   (reles[i] == "WILLRELE")) {
                                   vppwillrele = "|VDESC_VPP_WILLRELE";
                           };
                   };
                   if (releflags == "") {
                           printf ("\t0%s,\n", vppwillrele);
                   } else {
                           printf ("\t%s%s,\n", releflags, vppwillrele);
                   };
                   # vp offsets
                   printf ("\t%s_vp_offsets,\n", name);
                   # vpp (if any)
                   printf ("\t%s,\n", find_arg_with_type("struct vnode **"));
                   # cred (if any)
                   printf ("\t%s,\n", find_arg_with_type("struct ucred *"));
                   # proc (if any)
                   printf ("\t%s,\n", find_arg_with_type("struct proc *"));
                   # componentname
                   printf ("\t%s,\n", find_arg_with_type("struct componentname *"));
                   # transport layer information
                   printf ("\tNULL,\n};\n");
           }
   
           NF == 0 || $0 ~ "^#" {
                   next;
           }
           {
                   # get the function name
                   name = $1;
   
                   # get the function arguments
                   read_args();
   
                   # Print out the vop_F_vp_offsets structure.  This all depends
                   # on naming conventions and nothing else.
                   generate_operation_vp_offsets();
   
                   # Print out the vnodeop_desc structure.
                   generate_operation_desc();
   
                   printf "\n";
   
           }' < $SRC >> $CFILE
   # THINGS THAT DON'T WORK RIGHT YET.
   # 
   # Two existing BSD vnodeops (bwrite and strategy) don't take any vnodes as
   # arguments.  This means that these operations can't function successfully
   # through a bypass routine.
   #
   # Bwrite and strategy will be replaced when the VM page/buffer cache
   # integration happens.
   #
   # To get around this problem for now we handle these ops as special cases.
   
   cat << END_OF_SPECIAL_CASES >> $HEADER
   #include <sys/buf.h>
   struct vop_strategy_args {
           struct vnodeop_desc *a_desc;
           struct buf *a_bp;
   };
   extern struct vnodeop_desc vop_strategy_desc;
   static int VOP_STRATEGY __P((
           struct buf *bp));
   static __inline int VOP_STRATEGY(bp)
           struct buf *bp;
   {
           struct vop_strategy_args a;
   
           a.a_desc = VDESC(vop_strategy);
           a.a_bp = bp;
           return (VCALL((bp)->b_vp, VOFFSET(vop_strategy), &a));
   }
   
   struct vop_bwrite_args {
           struct vnodeop_desc *a_desc;
           struct buf *a_bp;
   };
   extern struct vnodeop_desc vop_bwrite_desc;
   static int VOP_BWRITE __P((
           struct buf *bp));
   static __inline int VOP_BWRITE(bp)
           struct buf *bp;
   {
           struct vop_bwrite_args a;
   
           a.a_desc = VDESC(vop_bwrite);
           a.a_bp = bp;
           return (VCALL((bp)->b_vp, VOFFSET(vop_bwrite), &a));
   }
   END_OF_SPECIAL_CASES
   
   cat << END_OF_SPECIAL_CASES >> $CFILE
   static int vop_strategy_vp_offsets[] = {
           VDESC_NO_OFFSET
   };
   struct vnodeop_desc vop_strategy_desc = {
           0,
           "vop_strategy",
           0,
           vop_strategy_vp_offsets,
           VDESC_NO_OFFSET,
           VDESC_NO_OFFSET,
           VDESC_NO_OFFSET,
           VDESC_NO_OFFSET,
           NULL,
   };
   static int vop_bwrite_vp_offsets[] = {
           VDESC_NO_OFFSET
   };
   struct vnodeop_desc vop_bwrite_desc = {
           0,
           "vop_bwrite",
           0,
           vop_bwrite_vp_offsets,
           VDESC_NO_OFFSET,
           VDESC_NO_OFFSET,
           VDESC_NO_OFFSET,
           VDESC_NO_OFFSET,
           NULL,
   };
   END_OF_SPECIAL_CASES
   
   # Add the vfs_op_descs array to the C file.
   $AWK '
           BEGIN {
                   printf("\nstruct vnodeop_desc *vfs_op_descs[] = {\n");
                   printf("\t&vop_default_desc,    /* MUST BE FIRST */\n");
                   printf("\t&vop_strategy_desc,   /* XXX: SPECIAL CASE */\n");
                   printf("\t&vop_bwrite_desc,     /* XXX: SPECIAL CASE */\n");
           }
           END {
                   printf("\tNULL\n};\n");
           }
           NF == 0 || $0 ~ "^#" {
                   next;
           }
           {
                   # Get the function name.
                   printf("\t&%s_desc,\n", $1);
   
                   # Skip the function arguments.
                   for (;;) {
                           if (getline <= 0)
                                   exit
                           if ($0 ~ "^};")
                                   break;
                   }
           }' < $SRC >> $CFILE
   

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