FreeBSD/Linux Kernel Cross Reference
sys/tools/makesyscalls.lua

     --
     -- SPDX-License-Identifier: BSD-2-Clause-FreeBSD
     --
     -- Copyright (c) 2019 Kyle Evans <kevans@FreeBSD.org>
     --
     -- 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.
    --
    -- THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
    --
    -- $FreeBSD$
    --
    
    
    -- We generally assume that this script will be run by flua, however we've
    -- carefully crafted modules for it that mimic interfaces provided by modules
    -- available in ports.  Currently, this script is compatible with lua from ports
    -- along with the compatible luafilesystem and lua-posix modules.
    local lfs = require("lfs")
    local unistd = require("posix.unistd")
    
    local savesyscall = -1
    local maxsyscall = -1
    local generated_tag = "@" .. "generated"
    
    -- Default configuration; any of these may get replaced by a configuration file
    -- optionally specified.
    local config = {
            os_id_keyword = "FreeBSD",
            abi_func_prefix = "",
            sysnames = "syscalls.c",
            sysproto = "../sys/sysproto.h",
            sysproto_h = "_SYS_SYSPROTO_H_",
            syshdr = "../sys/syscall.h",
            sysmk = "../sys/syscall.mk",
            syssw = "init_sysent.c",
            syscallprefix = "SYS_",
            switchname = "sysent",
            namesname = "syscallnames",
            systrace = "systrace_args.c",
            capabilities_conf = "capabilities.conf",
            capenabled = {},
            mincompat = 0,
            abi_type_suffix = "",
            abi_flags = "",
            abi_flags_mask = 0,
            ptr_intptr_t_cast = "intptr_t",
    }
    
    local config_modified = {}
    local cleantmp = true
    local tmpspace = "/tmp/sysent." .. unistd.getpid() .. "/"
    
    local output_files = {
            "sysnames",
            "syshdr",
            "sysmk",
            "syssw",
            "systrace",
            "sysproto",
    }
    
    -- These ones we'll create temporary files for; generation purposes.
    local temp_files = {
            "sysaue",
            "sysdcl",
            "syscompat",
            "syscompatdcl",
            "sysent",
            "sysinc",
            "sysarg",
            "sysprotoend",
            "systracetmp",
            "systraceret",
    }
    
    -- Opened files
    local files = {}
    
    local function cleanup()
            for _, v in pairs(files) do
                    assert(v:close())
            end
           if cleantmp then
                   if lfs.dir(tmpspace) then
                           for fname in lfs.dir(tmpspace) do
                                   if fname ~= "." and fname ~= ".." then
                                           assert(os.remove(tmpspace .. "/" ..
                                               fname))
                                   end
                           end
                   end
   
                   if lfs.attributes(tmpspace) and not lfs.rmdir(tmpspace) then
                           assert(io.stderr:write("Failed to clean up tmpdir: " ..
                               tmpspace .. "\n"))
                   end
           else
                   assert(io.stderr:write("Temp files left in " .. tmpspace ..
                       "\n"))
           end
   end
   
   local function abort(status, msg)
           assert(io.stderr:write(msg .. "\n"))
           cleanup()
           os.exit(status)
   end
   
   -- Each entry should have a value so we can represent abi flags as a bitmask
   -- for convenience.  One may also optionally provide an expr; this gets applied
   -- to each argument type to indicate whether this argument is subject to ABI
   -- change given the configured flags.
   local known_abi_flags = {
           long_size = {
                   value   = 0x00000001,
                   expr    = "_Contains[a-z_]*_long_",
           },
           time_t_size = {
                   value   = 0x00000002,
                   expr    = "_Contains[a-z_]*_timet_/",
           },
           pointer_args = {
                   value   = 0x00000004,
           },
           pointer_size = {
                   value   = 0x00000008,
                   expr    = "_Contains[a-z_]*_ptr_",
           },
   }
   
   local known_flags = {
           STD             = 0x00000001,
           OBSOL           = 0x00000002,
           RESERVED        = 0x00000004,
           UNIMPL          = 0x00000008,
           NODEF           = 0x00000010,
           NOARGS          = 0x00000020,
           NOPROTO         = 0x00000040,
           NOSTD           = 0x00000080,
           NOTSTATIC       = 0x00000100,
           CAPENABLED      = 0x00000200,
   
           -- Compat flags start from here.  We have plenty of space.
   }
   
   -- All compat_options entries should have five entries:
   --      definition: The preprocessor macro that will be set for this
   --      compatlevel: The level this compatibility should be included at.  This
   --          generally represents the version of FreeBSD that it is compatible
   --          with, but ultimately it's just the level of mincompat in which it's
   --          included.
   --      flag: The name of the flag in syscalls.master.
   --      prefix: The prefix to use for _args and syscall prototype.  This will be
   --          used as-is, without "_" or any other character appended.
   --      descr: The description of this compat option in init_sysent.c comments.
   -- The special "stdcompat" entry will cause the other five to be autogenerated.
   local compat_options = {
           {
                   definition = "COMPAT_43",
                   compatlevel = 3,
                   flag = "COMPAT",
                   prefix = "o",
                   descr = "old",
           },
           { stdcompat = "FREEBSD4" },
           { stdcompat = "FREEBSD6" },
           { stdcompat = "FREEBSD7" },
           { stdcompat = "FREEBSD10" },
           { stdcompat = "FREEBSD11" },
           { stdcompat = "FREEBSD12" },
   }
   
   local function trim(s, char)
           if s == nil then
                   return nil
           end
           if char == nil then
                   char = "%s"
           end
           return s:gsub("^" .. char .. "+", ""):gsub(char .. "+$", "")
   end
   
   -- We have to io.popen it, making sure it's properly escaped, and grab the
   -- output from the handle returned.
   local function exec(cmd)
           cmd = cmd:gsub('"', '\\"')
   
           local shcmd = "/bin/sh -c \"" .. cmd .. "\""
           local fh = io.popen(shcmd)
           local output = fh:read("a")
   
           fh:close()
           return output
   end
   
   -- config looks like a shell script; in fact, the previous makesyscalls.sh
   -- script actually sourced it in.  It had a pretty common format, so we should
   -- be fine to make various assumptions
   local function process_config(file)
           local cfg = {}
           local comment_line_expr = "^%s*#.*"
           -- We capture any whitespace padding here so we can easily advance to
           -- the end of the line as needed to check for any trailing bogus bits.
           -- Alternatively, we could drop the whitespace and instead try to
           -- use a pattern to strip out the meaty part of the line, but then we
           -- would need to sanitize the line for potentially special characters.
           local line_expr = "^([%w%p]+%s*)=(%s*[`\"]?[^\"`]+[`\"]?)"
   
           if not file then
                   return nil, "No file given"
           end
   
           local fh = assert(io.open(file))
   
           for nextline in fh:lines() do
                   -- Strip any whole-line comments
                   nextline = nextline:gsub(comment_line_expr, "")
                   -- Parse it into key, value pairs
                   local key, value = nextline:match(line_expr)
                   if key ~= nil and value ~= nil then
                           local kvp = key .. "=" .. value
                           key = trim(key)
                           value = trim(value)
                           local delim = value:sub(1,1)
                           if delim == '`' or delim == '"' then
                                   local trailing_context
                                   -- Strip off the key/value part
                                   trailing_context = nextline:sub(kvp:len() + 1)
                                   -- Strip off any trailing comment
                                   trailing_context = trailing_context:gsub("#.*$",
                                       "")
                                   -- Strip off leading/trailing whitespace
                                   trailing_context = trim(trailing_context)
                                   if trailing_context ~= "" then
                                           print(trailing_context)
                                           abort(1, "Malformed line: " .. nextline)
                                   end
                           end
                           if delim == '`' then
                                   -- Command substition may use $1 and $2 to mean
                                   -- the syscall definition file and itself
                                   -- respectively.  We'll go ahead and replace
                                   -- $[0-9] with respective arg in case we want to
                                   -- expand this in the future easily...
                                   value = trim(value, delim)
                                   for capture in value:gmatch("$([0-9]+)") do
                                           capture = tonumber(capture)
                                           if capture > #arg then
                                                   abort(1, "Not enough args: " ..
                                                       value)
                                           end
                                           value = value:gsub("$" .. capture,
                                               arg[capture])
                                   end
   
                                   value = exec(value)
                           elseif delim == '"' then
                                   value = trim(value, delim)
                           else
                                   -- Strip off potential comments
                                   value = value:gsub("#.*$", "")
                                   -- Strip off any padding whitespace
                                   value = trim(value)
                                   if value:match("%s") then
                                           abort(1, "Malformed config line: " ..
                                               nextline)
                                   end
                           end
                           cfg[key] = value
                   elseif not nextline:match("^%s*$") then
                           -- Make sure format violations don't get overlooked
                           -- here, but ignore blank lines.  Comments are already
                           -- stripped above.
                           abort(1, "Malformed config line: " .. nextline)
                   end
           end
   
           assert(io.close(fh))
           return cfg
   end
   
   local function grab_capenabled(file, open_fail_ok)
           local capentries = {}
           local commentExpr = "#.*"
   
           if file == nil then
                   print "No file"
                   return {}
           end
   
           local fh = io.open(file)
           if fh == nil then
                   if not open_fail_ok then
                           abort(1, "Failed to open " .. file)
                   end
                   return {}
           end
   
           for nextline in fh:lines() do
                   -- Strip any comments
                   nextline = nextline:gsub(commentExpr, "")
                   if nextline ~= "" then
                           capentries[nextline] = true
                   end
           end
   
           assert(io.close(fh))
           return capentries
   end
   
   local function process_compat()
           local nval = 0
           for _, v in pairs(known_flags) do
                   if v > nval then
                           nval = v
                   end
           end
   
           nval = nval << 1
           for _, v in pairs(compat_options) do
                   if v["stdcompat"] ~= nil then
                           local stdcompat = v["stdcompat"]
                           v["definition"] = "COMPAT_" .. stdcompat:upper()
                           v["compatlevel"] = tonumber(stdcompat:match("([0-9]+)$"))
                           v["flag"] = stdcompat:gsub("FREEBSD", "COMPAT")
                           v["prefix"] = stdcompat:lower() .. "_"
                           v["descr"] = stdcompat:lower()
                   end
   
                   local tmpname = "sys" .. v["flag"]:lower()
                   local dcltmpname = tmpname .. "dcl"
                   files[tmpname] = io.tmpfile()
                   files[dcltmpname] = io.tmpfile()
                   v["tmp"] = tmpname
                   v["dcltmp"] = dcltmpname
   
                   known_flags[v["flag"]] = nval
                   v["mask"] = nval
                   nval = nval << 1
   
                   v["count"] = 0
           end
   end
   
   local function process_abi_flags()
           local flags, mask = config["abi_flags"], 0
           for txtflag in flags:gmatch("([^|]+)") do
                   if known_abi_flags[txtflag] == nil then
                           abort(1, "Unknown abi_flag: " .. txtflag)
                   end
   
                   mask = mask | known_abi_flags[txtflag]["value"]
           end
   
           config["abi_flags_mask"] = mask
   end
   
   local function abi_changes(name)
           if known_abi_flags[name] == nil then
                   abort(1, "abi_changes: unknown flag: " .. name)
           end
   
           return config["abi_flags_mask"] & known_abi_flags[name]["value"] ~= 0
   end
   
   local function strip_abi_prefix(funcname)
           local abiprefix = config["abi_func_prefix"]
           local stripped_name
           if abiprefix ~= "" and funcname:find("^" .. abiprefix) then
                   stripped_name = funcname:gsub("^" .. abiprefix, "")
           else
                   stripped_name = funcname
           end
   
           return stripped_name
   end
   
   local function read_file(tmpfile)
           if files[tmpfile] == nil then
                   print("Not found: " .. tmpfile)
                   return
           end
   
           local fh = files[tmpfile]
           assert(fh:seek("set"))
           return assert(fh:read("a"))
   end
   
   local function write_line(tmpfile, line)
           if files[tmpfile] == nil then
                   print("Not found: " .. tmpfile)
                   return
           end
           assert(files[tmpfile]:write(line))
   end
   
   local function write_line_pfile(tmppat, line)
           for k in pairs(files) do
                   if k:match(tmppat) ~= nil then
                           assert(files[k]:write(line))
                   end
           end
   end
   
   local function isptrtype(type)
           return type:find("*") or type:find("caddr_t")
               -- XXX NOTYET: or type:find("intptr_t")
   end
   
   local process_syscall_def
   
   -- These patterns are processed in order on any line that isn't empty.
   local pattern_table = {
           {
                   pattern = "%s*$" .. config['os_id_keyword'],
                   process = function(_, _)
                           -- Ignore... ID tag
                   end,
           },
           {
                   dump_prevline = true,
                   pattern = "^#%s*include",
                   process = function(line)
                           line = line .. "\n"
                           write_line('sysinc', line)
                   end,
           },
           {
                   dump_prevline = true,
                   pattern = "^#",
                   process = function(line)
                           if line:find("^#%s*if") then
                                   savesyscall = maxsyscall
                           elseif line:find("^#%s*else") then
                                   maxsyscall = savesyscall
                           end
                           line = line .. "\n"
                           write_line('sysent', line)
                           write_line('sysdcl', line)
                           write_line('sysarg', line)
                           write_line_pfile('syscompat[0-9]*$', line)
                           write_line('sysnames', line)
                           write_line_pfile('systrace.*', line)
                   end,
           },
           {
                   -- Buffer anything else
                   pattern = ".+",
                   process = function(line, prevline)
                           local incomplete = line:find("\\$") ~= nil
                           -- Lines that end in \ get the \ stripped
                           -- Lines that start with a syscall number, prepend \n
                           line = trim(line):gsub("\\$", "")
                           if line:find("^[0-9]") and prevline then
                                   process_syscall_def(prevline)
                                   prevline = nil
                           end
   
                           prevline = (prevline or '') .. line
                           incomplete = incomplete or prevline:find(",$") ~= nil
                           incomplete = incomplete or prevline:find("{") ~= nil and
                               prevline:find("}") == nil
                           if prevline:find("^[0-9]") and not incomplete then
                                   process_syscall_def(prevline)
                                   prevline = nil
                           end
   
                           return prevline
                   end,
           },
   }
   
   local function process_sysfile(file)
           local capentries = {}
           local commentExpr = "^%s*;.*"
   
           if file == nil then
                   print "No file"
                   return {}
           end
   
           local fh = io.open(file)
           if fh == nil then
                   print("Failed to open " .. file)
                   return {}
           end
   
           local function do_match(nextline, prevline)
                   local pattern, handler, dump
                   for _, v in pairs(pattern_table) do
                           pattern = v['pattern']
                           handler = v['process']
                           dump = v['dump_prevline']
                           if nextline:match(pattern) then
                                   if dump and prevline then
                                           process_syscall_def(prevline)
                                           prevline = nil
                                   end
   
                                   return handler(nextline, prevline)
                           end
                   end
   
                   abort(1, "Failed to handle: " .. nextline)
           end
   
           local prevline
           for nextline in fh:lines() do
                   -- Strip any comments
                   nextline = nextline:gsub(commentExpr, "")
                   if nextline ~= "" then
                           prevline = do_match(nextline, prevline)
                   end
           end
   
           -- Dump any remainder
           if prevline ~= nil and prevline:find("^[0-9]") then
                   process_syscall_def(prevline)
           end
   
           assert(io.close(fh))
           return capentries
   end
   
   local function get_mask(flags)
           local mask = 0
           for _, v in ipairs(flags) do
                   if known_flags[v] == nil then
                           abort(1, "Checking for unknown flag " .. v)
                   end
   
                   mask = mask | known_flags[v]
           end
   
           return mask
   end
   
   local function get_mask_pat(pflags)
           local mask = 0
           for k, v in pairs(known_flags) do
                   if k:find(pflags) then
                           mask = mask | v
                   end
           end
   
           return mask
   end
   
   local function align_sysent_comment(col)
           write_line("sysent", "\t")
           col = col + 8 - col % 8
           while col < 56 do
                   write_line("sysent", "\t")
                   col = col + 8
           end
   end
   
   local function strip_arg_annotations(arg)
           arg = arg:gsub("_In[^ ]*[_)] ?", "")
           arg = arg:gsub("_Out[^ ]*[_)] ?", "")
           return trim(arg)
   end
   
   local function check_abi_changes(arg)
           for k, v in pairs(known_abi_flags) do
                   local expr = v["expr"]
                   if abi_changes(k) and expr ~= nil and arg:find(expr) then
                           return true
                   end
           end
   
           return false
   end
   
   local function process_args(args)
           local funcargs = {}
   
           for arg in args:gmatch("([^,]+)") do
                   local abi_change = not isptrtype(arg) or check_abi_changes(arg)
   
                   arg = strip_arg_annotations(arg)
   
                   local argname = arg:match("([^* ]+)$")
   
                   -- argtype is... everything else.
                   local argtype = trim(arg:gsub(argname .. "$", ""), nil)
   
                   if argtype == "" and argname == "void" then
                           goto out
                   end
   
                   -- XX TODO: Forward declarations? See: sysstubfwd in CheriBSD
                   if abi_change then
                           local abi_type_suffix = config["abi_type_suffix"]
                           argtype = argtype:gsub("_native ", "")
                           argtype = argtype:gsub("(struct [^ ]*)", "%1" ..
                               abi_type_suffix)
                           argtype = argtype:gsub("(union [^ ]*)", "%1" ..
                               abi_type_suffix)
                   end
   
                   funcargs[#funcargs + 1] = {
                           type = argtype,
                           name = argname,
                   }
           end
   
           ::out::
           return funcargs
   end
   
   local function handle_noncompat(sysnum, thr_flag, flags, sysflags, rettype,
       auditev, syscallret, funcname, funcalias, funcargs, argalias)
           local argssize
   
           if #funcargs > 0 or flags & known_flags["NODEF"] ~= 0 then
                   argssize = "AS(" .. argalias .. ")"
           else
                   argssize = "0"
           end
   
           write_line("systrace", string.format([[
           /* %s */
           case %d: {
   ]], funcname, sysnum))
           write_line("systracetmp", string.format([[
           /* %s */
           case %d:
   ]], funcname, sysnum))
           write_line("systraceret", string.format([[
           /* %s */
           case %d:
   ]], funcname, sysnum))
   
           if #funcargs > 0 then
                   write_line("systracetmp", "\t\tswitch (ndx) {\n")
                   write_line("systrace", string.format(
                       "\t\tstruct %s *p = params;\n", argalias))
   
                   local argtype, argname
                   for idx, arg in ipairs(funcargs) do
                           argtype = arg["type"]
                           argname = arg["name"]
   
                           argtype = trim(argtype:gsub("__restrict$", ""), nil)
                           -- Pointer arg?
                           if argtype:find("*") then
                                   write_line("systracetmp", string.format(
                                       "\t\tcase %d:\n\t\t\tp = \"userland %s\";\n\t\t\tbreak;\n",
                                       idx - 1, argtype))
                           else
                                   write_line("systracetmp", string.format(
                                       "\t\tcase %d:\n\t\t\tp = \"%s\";\n\t\t\tbreak;\n",
                                       idx - 1, argtype))
                           end
   
                           if isptrtype(argtype) then
                                   write_line("systrace", string.format(
                                       "\t\tuarg[%d] = (%s)p->%s; /* %s */\n",
                                       idx - 1, config["ptr_intptr_t_cast"],
                                       argname, argtype))
                           elseif argtype == "union l_semun" then
                                   write_line("systrace", string.format(
                                       "\t\tuarg[%d] = p->%s.buf; /* %s */\n",
                                       idx - 1, argname, argtype))
                           elseif argtype:sub(1,1) == "u" or argtype == "size_t" then
                                   write_line("systrace", string.format(
                                       "\t\tuarg[%d] = p->%s; /* %s */\n",
                                       idx - 1, argname, argtype))
                           else
                                   write_line("systrace", string.format(
                                       "\t\tiarg[%d] = p->%s; /* %s */\n",
                                       idx - 1, argname, argtype))
                           end
                   end
   
                   write_line("systracetmp",
                       "\t\tdefault:\n\t\t\tbreak;\n\t\t};\n")
   
                   write_line("systraceret", string.format([[
                   if (ndx == 0 || ndx == 1)
                           p = "%s";
                   break;
   ]], syscallret))
           end
           write_line("systrace", string.format(
               "\t\t*n_args = %d;\n\t\tbreak;\n\t}\n", #funcargs))
           write_line("systracetmp", "\t\tbreak;\n")
   
           local nargflags = get_mask({"NOARGS", "NOPROTO", "NODEF"})
           if flags & nargflags == 0 then
                   if #funcargs > 0 then
                           write_line("sysarg", string.format("struct %s {\n",
                               argalias))
                           for _, v in ipairs(funcargs) do
                                   local argname, argtype = v["name"], v["type"]
                                   write_line("sysarg", string.format(
                                       "\tchar %s_l_[PADL_(%s)]; %s %s; char %s_r_[PADR_(%s)];\n",
                                       argname, argtype,
                                       argtype, argname,
                                       argname, argtype))
                           end
                           write_line("sysarg", "};\n")
                   else
                           write_line("sysarg", string.format(
                               "struct %s {\n\tregister_t dummy;\n};\n", argalias))
                   end
           end
   
           local protoflags = get_mask({"NOPROTO", "NODEF"})
           if flags & protoflags == 0 then
                   if funcname == "nosys" or funcname == "lkmnosys" or
                       funcname == "sysarch" or funcname:find("^freebsd") or
                       funcname:find("^linux") or
                       funcname:find("^cloudabi") then
                           write_line("sysdcl", string.format(
                               "%s\t%s(struct thread *, struct %s *)",
                               rettype, funcname, argalias))
                   else
                           write_line("sysdcl", string.format(
                               "%s\tsys_%s(struct thread *, struct %s *)",
                               rettype, funcname, argalias))
                   end
                   write_line("sysdcl", ";\n")
                   write_line("sysaue", string.format("#define\t%sAUE_%s\t%s\n",
                       config['syscallprefix'], funcalias, auditev))
           end
   
           write_line("sysent",
               string.format("\t{ .sy_narg = %s, .sy_call = (sy_call_t *)", argssize))
           local column = 8 + 2 + #argssize + 15
   
           if flags & known_flags["NOSTD"] ~= 0 then
                   write_line("sysent", string.format(
                       "lkmressys, .sy_auevent = AUE_NULL, " ..
                       ".sy_flags = %s, .sy_thrcnt = SY_THR_ABSENT },",
                       sysflags))
                   column = column + #"lkmressys" + #"AUE_NULL" + 3
           else
                   if funcname == "nosys" or funcname == "lkmnosys" or
                       funcname == "sysarch" or funcname:find("^freebsd") or
                       funcname:find("^linux") or
                       funcname:find("^cloudabi") then
                           write_line("sysent", string.format(
                               "%s, .sy_auevent = %s, .sy_flags = %s, .sy_thrcnt = %s },",
                               funcname, auditev, sysflags, thr_flag))
                           column = column + #funcname + #auditev + #sysflags + 3
                   else
                           write_line("sysent", string.format(
                               "sys_%s, .sy_auevent = %s, .sy_flags = %s, .sy_thrcnt = %s },",
                               funcname, auditev, sysflags, thr_flag))
                           column = column + #funcname + #auditev + #sysflags + 7
                   end
           end
   
           align_sysent_comment(column)
           write_line("sysent", string.format("/* %d = %s */\n",
               sysnum, funcalias))
           write_line("sysnames", string.format("\t\"%s\",\t\t\t/* %d = %s */\n",
               funcalias, sysnum, funcalias))
   
           if flags & known_flags["NODEF"] == 0 then
                   write_line("syshdr", string.format("#define\t%s%s\t%d\n",
                       config['syscallprefix'], funcalias, sysnum))
                   write_line("sysmk", string.format(" \\\n\t%s.o",
                       funcalias))
           end
   end
   
   local function handle_obsol(sysnum, funcname, comment)
           write_line("sysent",
               "\t{ .sy_narg = 0, .sy_call = (sy_call_t *)nosys, " ..
               ".sy_auevent = AUE_NULL, .sy_flags = 0, .sy_thrcnt = SY_THR_ABSENT },")
           align_sysent_comment(34)
   
           write_line("sysent", string.format("/* %d = obsolete %s */\n",
               sysnum, comment))
           write_line("sysnames", string.format(
               "\t\"obs_%s\",\t\t\t/* %d = obsolete %s */\n",
               funcname, sysnum, comment))
           write_line("syshdr", string.format("\t\t\t\t/* %d is obsolete %s */\n",
               sysnum, comment))
   end
   
   local function handle_compat(sysnum, thr_flag, flags, sysflags, rettype,
       auditev, funcname, funcalias, funcargs, argalias)
           local argssize, out, outdcl, wrap, prefix, descr
   
           if #funcargs > 0 or flags & known_flags["NODEF"] ~= 0 then
                   argssize = "AS(" .. argalias .. ")"
           else
                   argssize = "0"
           end
   
           for _, v in pairs(compat_options) do
                   if flags & v["mask"] ~= 0 then
                           if config["mincompat"] > v["compatlevel"] then
                                   funcname = strip_abi_prefix(funcname)
                                   funcname = v["prefix"] .. funcname
                                   return handle_obsol(sysnum, funcname, funcname)
                           end
                           v["count"] = v["count"] + 1
                           out = v["tmp"]
                           outdcl = v["dcltmp"]
                           wrap = v["flag"]:lower()
                           prefix = v["prefix"]
                           descr = v["descr"]
                           goto compatdone
                   end
           end
   
           ::compatdone::
           local dprotoflags = get_mask({"NOPROTO", "NODEF"})
           local nargflags = dprotoflags | known_flags["NOARGS"]
           if #funcargs > 0 and flags & nargflags == 0 then
                   write_line(out, string.format("struct %s {\n", argalias))
                   for _, v in ipairs(funcargs) do
                           local argname, argtype = v["name"], v["type"]
                           write_line(out, string.format(
                               "\tchar %s_l_[PADL_(%s)]; %s %s; char %s_r_[PADR_(%s)];\n",
                               argname, argtype,
                               argtype, argname,
                               argname, argtype))
                   end
                   write_line(out, "};\n")
           elseif flags & nargflags == 0 then
                   write_line("sysarg", string.format(
                       "struct %s {\n\tregister_t dummy;\n};\n", argalias))
           end
           if flags & dprotoflags == 0 then
                   write_line(outdcl, string.format(
                       "%s\t%s%s(struct thread *, struct %s *);\n",
                       rettype, prefix, funcname, argalias))
                   write_line("sysaue", string.format(
                       "#define\t%sAUE_%s%s\t%s\n", config['syscallprefix'],
                       prefix, funcname, auditev))
           end
   
           if flags & known_flags['NOSTD'] ~= 0 then
                   write_line("sysent", string.format(
                       "\t{ .sy_narg = %s, .sy_call = (sy_call_t *)%s, " ..
                       ".sy_auevent = %s, .sy_flags = 0, " ..
                       ".sy_thrcnt = SY_THR_ABSENT },",
                       "0", "lkmressys", "AUE_NULL"))
                   align_sysent_comment(8 + 2 + #"0" + 15 + #"lkmressys" +
                       #"AUE_NULL" + 3)
           else
                   write_line("sysent", string.format(
                       "\t{ %s(%s,%s), .sy_auevent = %s, .sy_flags = %s, .sy_thrcnt = %s },",
                       wrap, argssize, funcname, auditev, sysflags, thr_flag))
                   align_sysent_comment(8 + 9 + #argssize + 1 + #funcname +
                       #auditev + #sysflags + 4)
           end
   
           write_line("sysent", string.format("/* %d = %s %s */\n",
               sysnum, descr, funcalias))
           write_line("sysnames", string.format(
               "\t\"%s.%s\",\t\t/* %d = %s %s */\n",
               wrap, funcalias, sysnum, descr, funcalias))
           -- Do not provide freebsdN_* symbols in libc for < FreeBSD 7
           local nosymflags = get_mask({"COMPAT", "COMPAT4", "COMPAT6"})
           if flags & nosymflags ~= 0 then
                   write_line("syshdr", string.format(
                       "\t\t\t\t/* %d is %s %s */\n",
                       sysnum, descr, funcalias))
           elseif flags & known_flags["NODEF"] == 0 then
                   write_line("syshdr", string.format("#define\t%s%s%s\t%d\n",
                       config['syscallprefix'], prefix, funcalias, sysnum))
                   write_line("sysmk", string.format(" \\\n\t%s%s.o",
                       prefix, funcalias))
           end
   end
   
   local function handle_unimpl(sysnum, sysstart, sysend, comment)
           if sysstart == nil and sysend == nil then
                   sysstart = tonumber(sysnum)
                   sysend = tonumber(sysnum)
           end
   
           sysnum = sysstart
           while sysnum <= sysend do
                   write_line("sysent", string.format(
                       "\t{ .sy_narg = 0, .sy_call = (sy_call_t *)nosys, " ..
                       ".sy_auevent = AUE_NULL, .sy_flags = 0, " ..
                       ".sy_thrcnt = SY_THR_ABSENT },\t\t\t/* %d = %s */\n",
                       sysnum, comment))
                   write_line("sysnames", string.format(
                       "\t\"#%d\",\t\t\t/* %d = %s */\n",
                       sysnum, sysnum, comment))
                   sysnum = sysnum + 1
           end
   end
   
   local function handle_reserved(sysnum, sysstart, sysend, comment)
           handle_unimpl(sysnum, sysstart, sysend, "reserved for local use")
   end
   
   process_syscall_def = function(line)
           local sysstart, sysend, flags, funcname, sysflags
           local thr_flag, syscallret
           local orig = line
           flags = 0
           thr_flag = "SY_THR_STATIC"
   
           -- Parse out the interesting information first
           local initialExpr = "^([^%s]+)%s+([^%s]+)%s+([^%s]+)%s*"
           local sysnum, auditev, allflags = line:match(initialExpr)
   
           if sysnum == nil or auditev == nil or allflags == nil then
                   -- XXX TODO: Better?
                   abort(1, "Completely malformed: " .. line)
           end
   
           if sysnum:find("-") then
                   sysstart, sysend = sysnum:match("^([%d]+)-([%d]+)$")
                   if sysstart == nil or sysend == nil then
                           abort(1, "Malformed range: " .. sysnum)
                   end
                   sysnum = nil
                   sysstart = tonumber(sysstart)
                   sysend = tonumber(sysend)
                   if sysstart ~= maxsyscall + 1 then
                           abort(1, "syscall number out of sync, missing " ..
                               maxsyscall + 1)
                   end
           else
                   sysnum = tonumber(sysnum)
                   if sysnum ~= maxsyscall + 1 then
                           abort(1, "syscall number out of sync, missing " ..
                               maxsyscall + 1)
                   end
           end
   
           -- Split flags
           for flag in allflags:gmatch("([^|]+)") do
                   if known_flags[flag] == nil then
                           abort(1, "Unknown flag " .. flag .. " for " ..  sysnum)
                   end
                   flags = flags | known_flags[flag]
           end
   
           if (flags & get_mask({"RESERVED", "UNIMPL"})) == 0 and sysnum == nil then
                   abort(1, "Range only allowed with RESERVED and UNIMPL: " .. line)
           end
   
           if (flags & known_flags["NOTSTATIC"]) ~= 0 then
                   thr_flag = "SY_THR_ABSENT"
           end
   
           -- Strip earlier bits out, leave declaration + alt
           line = line:gsub("^.+" .. allflags .. "%s*", "")
   
           local decl_fnd = line:find("^{") ~= nil
           if decl_fnd and line:find("}") == nil then
                   abort(1, "Malformed, no closing brace: " .. line)
           end
   
           local decl, alt
           if decl_fnd then
                   line = line:gsub("^{", "")
                   decl, alt = line:match("([^}]*)}[%s]*(.*)$")
           else
                   alt = line
           end
   
           if decl == nil and alt == nil then
                   abort(1, "Malformed bits: " .. line)
           end
   
           local funcalias, funcomment, argalias, rettype, args
           if not decl_fnd and alt ~= nil and alt ~= "" then
                   -- Peel off one entry for name
                   funcname = trim(alt:match("^([^%s]+)"), nil)
                   alt = alt:gsub("^([^%s]+)[%s]*", "")
           end
           -- Do we even need it?
           if flags & get_mask({"OBSOL", "UNIMPL"}) ~= 0 then
                   local NF = 0
                   for _ in orig:gmatch("[^%s]+") do
                           NF = NF + 1
                   end
   
                  funcomment = funcname or ''
                  if NF < 6 then
                          funcomment = funcomment .. " " .. alt
                  end
  
                  funcomment = trim(funcomment)
  
  --              if funcname ~= nil then
  --              else
  --                      funcomment = trim(alt)
  --              end
                  goto skipalt
          end
  
          if alt ~= nil and alt ~= "" then
                  local altExpr = "^([^%s]+)%s+([^%s]+)%s+([^%s]+)"
                  funcalias, argalias, rettype = alt:match(altExpr)
                  funcalias = trim(funcalias)
                  if funcalias == nil or argalias == nil or rettype == nil then
                          abort(1, "Malformed alt: " .. line)
                  end
          end
          if decl_fnd then
                  -- Don't clobber rettype set in the alt information
                  if rettype == nil then
                          rettype = "int"
                  end
                  -- Peel off the return type
                  syscallret = line:match("([^%s]+)%s")
                  line = line:match("[^%s]+%s(.+)")
                  -- Pointer incoming
                  if line:sub(1,1) == "*" then
                          syscallret = syscallret .. " "
                  end
                  while line:sub(1,1) == "*" do
                          line = line:sub(2)
                          syscallret = syscallret .. "*"
                  end
                  funcname = line:match("^([^(]+)%(")
                  if funcname == nil then
                          abort(1, "Not a signature? " .. line)
                  end
                  args = line:match("^[^(]+%((.+)%)[^)]*$")
                  args = trim(args, '[,%s]')
          end
  
          ::skipalt::
  
          if funcname == nil then
                  funcname = funcalias
          end
  
          funcname = trim(funcname)
  
          sysflags = "0"
  
          -- NODEF events do not get audited
          if flags & known_flags['NODEF'] ~= 0 then
                  auditev = 'AUE_NULL'
          end
  
          -- If applicable; strip the ABI prefix from the name
          local stripped_name = strip_abi_prefix(funcname)
  
          if flags & known_flags['CAPENABLED'] ~= 0 or
              config["capenabled"][funcname] ~= nil or
              config["capenabled"][stripped_name] ~= nil then
                  sysflags = "SYF_CAPENABLED"
          end
  
          local funcargs = {}
          if args ~= nil then
                  funcargs = process_args(args)
          end
  
          local argprefix = ''
          if abi_changes("pointer_args") then
                  for _, v in ipairs(funcargs) do
                          if isptrtype(v["type"]) then
                                  -- argalias should be:
                                  --   COMPAT_PREFIX + ABI Prefix + funcname
                                  argprefix = config['abi_func_prefix']
                                  funcalias = config['abi_func_prefix'] ..
                                      funcname
                                  goto ptrfound
                          end
                  end
                  ::ptrfound::
          end
          if funcalias == nil or funcalias == "" then
                  funcalias = funcname
          end
  
          if argalias == nil and funcname ~= nil then
                  argalias = argprefix .. funcname .. "_args"
                  for _, v in pairs(compat_options) do
                          local mask = v["mask"]
                          if (flags & mask) ~= 0 then
                                  -- Multiple aliases doesn't seem to make
                                  -- sense.
                                  argalias = v["prefix"] .. argalias
                                  goto out
                          end
                  end
                  ::out::
          elseif argalias ~= nil then
                  argalias = argprefix .. argalias
          end
  
          local ncompatflags = get_mask({"STD", "NODEF", "NOARGS", "NOPROTO",
              "NOSTD"})
          local compatflags = get_mask_pat("COMPAT.*")
          -- Now try compat...
          if flags & compatflags ~= 0 then
                  if flags & known_flags['STD'] ~= 0 then
                          abort(1, "Incompatible COMPAT/STD: " .. line)
                  end
                  handle_compat(sysnum, thr_flag, flags, sysflags, rettype,
                      auditev, funcname, funcalias, funcargs, argalias)
          elseif flags & ncompatflags ~= 0 then
                  handle_noncompat(sysnum, thr_flag, flags, sysflags, rettype,
                      auditev, syscallret, funcname, funcalias, funcargs,
                      argalias)
          elseif flags & known_flags["OBSOL"] ~= 0 then
                  handle_obsol(sysnum, funcname, funcomment)
          elseif flags & known_flags["RESERVED"] ~= 0 then
                  handle_reserved(sysnum, sysstart, sysend)
          elseif flags & known_flags["UNIMPL"] ~= 0 then
                  handle_unimpl(sysnum, sysstart, sysend, funcomment)
          else
                  abort(1, "Bad flags? " .. line)
          end
  
          if sysend ~= nil then
                  maxsyscall = sysend
          elseif sysnum ~= nil then
                  maxsyscall = sysnum
          end
  end
  
  -- Entry point
  
  if #arg < 1 or #arg > 2 then
          error("usage: " .. arg[0] .. " input-file <config-file>")
  end
  
  local sysfile, configfile = arg[1], arg[2]
  
  -- process_config either returns nil and a message, or a
  -- table that we should merge into the global config
  if configfile ~= nil then
          local res = assert(process_config(configfile))
  
          for k, v in pairs(res) do
                  if v ~= config[k] then
                          config[k] = v
                          config_modified[k] = true
                  end
          end
  end
  
  -- We ignore errors here if we're relying on the default configuration.
  if not config_modified["capenabled"] then
          config["capenabled"] = grab_capenabled(config['capabilities_conf'],
              config_modified["capabilities_conf"] == nil)
  elseif config["capenabled"] ~= "" then
          -- Due to limitations in the config format mostly, we'll have a comma
          -- separated list.  Parse it into lines
          local capenabled = {}
          -- print("here: " .. config["capenabled"])
          for sysc in config["capenabled"]:gmatch("([^,]+)") do
                  capenabled[sysc] = true
          end
          config["capenabled"] = capenabled
  end
  process_compat()
  process_abi_flags()
  
  if not lfs.mkdir(tmpspace) then
          error("Failed to create tempdir " .. tmpspace)
  end
  
  -- XXX Revisit the error handling here, we should probably move the rest of this
  -- into a function that we pcall() so we can catch the errors and clean up
  -- gracefully.
  for _, v in ipairs(temp_files) do
          local tmpname = tmpspace .. v
          files[v] = io.open(tmpname, "w+")
          -- XXX Revisit these with a pcall() + error handler
          if not files[v] then
                  abort(1, "Failed to open temp file: " .. tmpname)
          end
  end
  
  for _, v in ipairs(output_files) do
          local tmpname = tmpspace .. v
          files[v] = io.open(tmpname, "w+")
          -- XXX Revisit these with a pcall() + error handler
          if not files[v] then
                  abort(1, "Failed to open temp output file: " .. tmpname)
          end
  end
  
  -- Write out all of the preamble bits
  write_line("sysent", string.format([[
  
  /* The casts are bogus but will do for now. */
  struct sysent %s[] = {
  ]], config['switchname']))
  
  write_line("syssw", string.format([[/*
   * System call switch table.
   *
   * DO NOT EDIT-- this file is automatically %s.
   * $%s$
   */
  
  ]], generated_tag, config['os_id_keyword']))
  
  write_line("sysarg", string.format([[/*
   * System call prototypes.
   *
   * DO NOT EDIT-- this file is automatically %s.
   * $%s$
   */
  
  #ifndef %s
  #define %s
  
  #include <sys/signal.h>
  #include <sys/acl.h>
  #include <sys/cpuset.h>
  #include <sys/domainset.h>
  #include <sys/_ffcounter.h>
  #include <sys/_semaphore.h>
  #include <sys/ucontext.h>
  #include <sys/wait.h>
  
  #include <bsm/audit_kevents.h>
  
  struct proc;
  
  struct thread;
  
  #define PAD_(t) (sizeof(register_t) <= sizeof(t) ? \
                  0 : sizeof(register_t) - sizeof(t))
  
  #if BYTE_ORDER == LITTLE_ENDIAN
  #define PADL_(t)        0
  #define PADR_(t)        PAD_(t)
  #else
  #define PADL_(t)        PAD_(t)
  #define PADR_(t)        0
  #endif
  
  ]], generated_tag, config['os_id_keyword'], config['sysproto_h'],
      config['sysproto_h']))
  for _, v in pairs(compat_options) do
          write_line(v["tmp"], string.format("\n#ifdef %s\n\n", v["definition"]))
  end
  
  write_line("sysnames", string.format([[/*
   * System call names.
   *
   * DO NOT EDIT-- this file is automatically %s.
   * $%s$
   */
  
  const char *%s[] = {
  ]], generated_tag, config['os_id_keyword'], config['namesname']))
  
  write_line("syshdr", string.format([[/*
   * System call numbers.
   *
   * DO NOT EDIT-- this file is automatically %s.
   * $%s$
   */
  
  ]], generated_tag, config['os_id_keyword']))
  
  write_line("sysmk", string.format([[# FreeBSD system call object files.
  # DO NOT EDIT-- this file is automatically %s.
  # $%s$
  MIASM = ]], generated_tag, config['os_id_keyword']))
  
  write_line("systrace", string.format([[/*
   * System call argument to DTrace register array converstion.
   *
   * DO NOT EDIT-- this file is automatically %s.
   * $%s$
   * This file is part of the DTrace syscall provider.
   */
  
  static void
  systrace_args(int sysnum, void *params, uint64_t *uarg, int *n_args)
  {
          int64_t *iarg = (int64_t *)uarg;
          switch (sysnum) {
  ]], generated_tag, config['os_id_keyword']))
  
  write_line("systracetmp", [[static void
  systrace_entry_setargdesc(int sysnum, int ndx, char *desc, size_t descsz)
  {
          const char *p = NULL;
          switch (sysnum) {
  ]])
  
  write_line("systraceret", [[static void
  systrace_return_setargdesc(int sysnum, int ndx, char *desc, size_t descsz)
  {
          const char *p = NULL;
          switch (sysnum) {
  ]])
  
  -- Processing the sysfile will parse out the preprocessor bits and put them into
  -- the appropriate place.  Any syscall-looking lines get thrown into the sysfile
  -- buffer, one per line, for later processing once they're all glued together.
  process_sysfile(sysfile)
  
  write_line("sysinc",
      "\n#define AS(name) (sizeof(struct name) / sizeof(register_t))\n")
  
  for _, v in pairs(compat_options) do
          if v["count"] > 0 then
                  write_line("sysinc", string.format([[
  
  #ifdef %s
  #define %s(n, name) .sy_narg = n, .sy_call = (sy_call_t *)__CONCAT(%s, name)
  #else
  #define %s(n, name) .sy_narg = 0, .sy_call = (sy_call_t *)nosys
  #endif
  ]], v["definition"], v["flag"]:lower(), v["prefix"], v["flag"]:lower()))
          end
  
          write_line(v["dcltmp"], string.format("\n#endif /* %s */\n\n",
              v["definition"]))
  end
  
  write_line("sysprotoend", string.format([[
  
  #undef PAD_
  #undef PADL_
  #undef PADR_
  
  #endif /* !%s */
  ]], config["sysproto_h"]))
  
  write_line("sysmk", "\n")
  write_line("sysent", "};\n")
  write_line("sysnames", "};\n")
  -- maxsyscall is the highest seen; MAXSYSCALL should be one higher
  write_line("syshdr", string.format("#define\t%sMAXSYSCALL\t%d\n",
      config["syscallprefix"], maxsyscall + 1))
  write_line("systrace", [[
          default:
                  *n_args = 0;
                  break;
          };
  }
  ]])
  
  write_line("systracetmp", [[
          default:
                  break;
          };
          if (p != NULL)
                  strlcpy(desc, p, descsz);
  }
  ]])
  
  write_line("systraceret", [[
          default:
                  break;
          };
          if (p != NULL)
                  strlcpy(desc, p, descsz);
  }
  ]])
  
  -- Finish up; output
  write_line("syssw", read_file("sysinc"))
  write_line("syssw", read_file("sysent"))
  
  write_line("sysproto", read_file("sysarg"))
  write_line("sysproto", read_file("sysdcl"))
  for _, v in pairs(compat_options) do
          write_line("sysproto", read_file(v["tmp"]))
          write_line("sysproto", read_file(v["dcltmp"]))
  end
  write_line("sysproto", read_file("sysaue"))
  write_line("sysproto", read_file("sysprotoend"))
  
  write_line("systrace", read_file("systracetmp"))
  write_line("systrace", read_file("systraceret"))
  
  for _, v in ipairs(output_files) do
          local target = config[v]
          if target ~= "/dev/null" then
                  local fh = assert(io.open(target, "w+"))
                  if fh == nil then
                          abort(1, "Failed to open '" .. target .. "'")
                  end
                  assert(fh:write(read_file(v)))
                  assert(fh:close())
          end
  end
  
  cleanup()

Cache object: 70a299ed0f89e524ca9eb49493191719