1# Reply server mig-output massager 2# 3# Copyright (C) 1995-2020 Free Software Foundation, Inc. 4# 5# Written by Miles Bader <miles@gnu.ai.mit.edu> 6# 7# This program is free software; you can redistribute it and/or 8# modify it under the terms of the GNU General Public License as 9# published by the Free Software Foundation; either version 3, or (at 10# your option) any later version. 11# 12# This program is distributed in the hope that it will be useful, but 13# WITHOUT ANY WARRANTY; without even the implied warranty of 14# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15# General Public License for more details. 16# 17# You should have received a copy of the GNU General Public License 18# along with this program. If not, see <http://www.gnu.org/licenses/>. 19# 20# This awk script hacks the output of mig-generated reply server code 21# so that it allows replies with just the error-code in them (as this is 22# how mig returns errors). 23# 24# It is highly, highly, dependent on the exact format of mig output. Ick. 25# 26 27BEGIN { parse_phase = 0; } 28 29/^}/ { parse_phase = 0; } 30 31parse_phase == 0 && /^mig_internal void _X[a-zA-Z0-9_]*_reply/ { 32 # The start of a mig server routine. Reset everything. Note that we only 33 # mess with rpcs that have the suffix `_reply'. 34 num_args = 0; 35 num_checks = 0; 36 parse_phase = 1; 37 print; next; 38} 39 40parse_phase == 1 && /^[\t ]*typedef struct/ { 41 # The first structure in the server routine should describe the arguments 42 parse_phase = 2; 43 print; next; 44} 45 46parse_phase == 2 { 47 # The message header field in the args structure, which skip. 48 parse_phase = 3; 49 print; next; 50} 51 52parse_phase == 3 && /} Request/ { 53 # The args structure is over. 54 if (num_args > 1) 55 parse_phase = 5; 56 else 57 # There's no extra args that could screw up the normal mechanism for 58 # error returns, so we don't have to insert any new code. 59 parse_phase = 0; 60 print; next; 61} 62 63parse_phase == 3 && num_args == 0 { 64 # The type field for an argument. 65 # This won't be accurate in case of unions being used in the Request struct, 66 # but that doesn't matter, as we'll only be looking at arg_type_code_name[0], 67 # which will not be a union type. 68 arg_type_code_name[num_args] = $2; 69 sub (/;$/, "", arg_type_code_name[num_args]) # Get rid of the semi-colon 70 parse_phase = 4; 71 print; next; 72} 73 74parse_phase == 3 && num_args == 1 { 75 # We've got more than one argument (but we don't care what it is). 76 num_args++; 77 print; next; 78} 79 80parse_phase == 3 { 81 # We've know everything we need; now just wait for the end of the Request 82 # struct. 83 print; next; 84} 85 86parse_phase == 4 { 87 # The value field for an argument. 88 # This won't be accurate in case of unions being used in the Request struct, 89 # but that doesn't matter, as we'll only be looking at arg_name[0], which 90 # will not be a union type. 91 arg_name[num_args] = $2; 92 sub (/;$/, "", arg_name[num_args]) # Get rid of the semi-colon 93 num_args++; 94 parse_phase = 3; 95 print; next; 96} 97 98parse_phase == 5 && /^[ \t]*(auto |static )?const mach_msg_type_t/ { 99 # The type check structure for an argument. 100 arg_check_name[num_checks] = $(NF - 2); 101 num_checks++; 102 print; next; 103} 104 105parse_phase == 5 && /^[ \t]*mig_external kern_return_t/ { 106 # The declaration of the user server function for this rpc. 107 user_function_name = $3; 108 print; next; 109} 110 111parse_phase == 5 && /^#if[ \t]TypeCheck/ { 112 # Keep going if we have not yet collected the type check structures. 113 if (num_checks == 0) 114 { 115 print; next; 116 } 117 118 # The first args type checking statement; we need to insert our chunk of 119 # code that bypasses all the type checks if this is an error return, after 120 # which we're done until we get to the next function. Handily, the size 121 # of mig's Reply structure is also the size of the alternate Request 122 # structure that we want to check for. 123 print "\tif (In0P->Head.msgh_size == sizeof (Reply)"; 124 print "\t && ! (In0P->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)"; 125 print "\t && ! BAD_TYPECHECK(&In0P->" arg_type_code_name[0] ", &" arg_check_name[0] ")"; 126 print "\t && In0P->" arg_name[0] " != 0)"; 127 print "\t /* Error return, only the error code argument is passed. */"; 128 print "\t {"; 129 # Force the function user_function_name into a type that only takes the first 130 # two arguments. 131 # This is possibly bogus, but easier than supplying bogus values for all 132 # the other args (we can't just pass 0 for them, as they might not be scalar). 133 print "\t void * __error_call = " user_function_name ";"; 134 print "\t OutP->RetCode = (*(kern_return_t (*)(mach_port_t, kern_return_t)) __error_call) (In0P->Head.msgh_request_port, In0P->" arg_name[0] ");"; 135 print "\t return;"; 136 print "\t }"; 137 print ""; 138 parse_phase = 0; 139 print; next; 140} 141 142{ print; } 143