1 #! /bin/bash 2 3 #set -x 4 5 ######################################################################## 6 # 7 # File: reg-hunt 8 # Author: Janis Johnson <janis187 (at] us.ibm.com> 9 # Date: 2003/08/19 10 # 11 # Search for the patch identifier for which results for a test changed, 12 # using a binary search. The functionality for getting sources, 13 # building the component to test, and running the test are in other 14 # scripts that are run from here. Before the search begins, we verify 15 # that we get the expected behavior for the first and last patch 16 # identifiers. 17 # 18 # Define these in a file whose name is the argument to this script: 19 # LOW_PATCH: Patch identifier. 20 # HIGH_PATCH: Patch identifier. 21 # REG_UPDATE: Pathname of script to update your source tree; returns 22 # zero for success, nonzero for failure. 23 # REG_BUILD: Pathname of script to build enough of the product to run 24 # the test; returns zero for success, nonzero for failure. 25 # REG_TEST: Pathname of script to run the test; returns 1 if we 26 # should search later patches, 0 if we should search 27 # earlier patches, and something else if there was an 28 # unexpected failure. 29 # Optional: 30 # REG_REPORT Pathname of script to call at the end with the id of the 31 # patch that caused the change in behavior. 32 # REG_FINISH Pathname of script to call at the end with the two final 33 # patch identifiers as arguments. 34 # REG_NEWMID Pathname of script to call when a build has failed, with 35 # arguments of the failed id and the current low and high 36 # SKIP_LOW If 1, skip verifying the low patch identifier of the 37 # range; define this only if you're restarting and have 38 # already tested the low patch. 39 # SKIP_HIGH If 1, skip verifying the high patch identifier of the 40 # range; define this only if you're restarting and have 41 # already tested the high patch. 42 # FIRST_MID Use this as the first midpoint, to avoid a midpoint that 43 # is known not to build. 44 # VERBOSITY Default is 0, to print only errors and final message. 45 # DATE_IN_MSG If set to anything but 0, include the time and date in 46 # messages. 47 # 48 # 49 # 50 # Copyright (C) 2002-2024 Free Software Foundation, Inc. 51 # 52 # This file is free software; you can redistribute it and/or modify 53 # it under the terms of the GNU General Public License as published by 54 # the Free Software Foundation; either version 3 of the License, or 55 # (at your option) any later version. 56 # 57 # This program is distributed in the hope that it will be useful, 58 # but WITHOUT ANY WARRANTY; without even the implied warranty of 59 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 60 # GNU General Public License for more details. 61 # 62 # For a copy of the GNU General Public License, write the the 63 # Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 64 # Boston, MA 02111-1301, USA. 65 # 66 ######################################################################## 67 68 ######################################################################## 69 # Functions 70 ######################################################################## 71 72 # Issue a message if its verbosity level is high enough. 73 74 msg() { 75 test ${1} -gt ${VERBOSITY} && return 76 77 if [ "x${DATE_IN_MSG}" = "x" ]; then 78 echo "${2}" 79 else 80 echo "`date` ${2}" 81 fi 82 } 83 84 # Issue an error message and exit with a non-zero status. If there 85 # is a valid current range whose end points have been tested, report 86 # it so the user can start again from there. 87 88 error() { 89 msg 0 "error: ${1}" 90 test ${VALID_RANGE} -eq 1 && \ 91 echo "current range:" 92 echo "LOW_PATCH=${LATER_THAN}" 93 echo "HIGH_PATCH=${EARLIER_THAN}" 94 exit 1 95 } 96 97 # Build the components to test using sources as of a particular patch 98 # and run a test case. Pass each of the scripts the patch identifier 99 # that we're testing; the first one needs it, the others can ignore it 100 # if they want. 101 102 process_patch () { 103 TEST_ID=${1} 104 105 # If we're keeping track of known failures, see if TEST_ID is one and 106 # if so, don't bother updating sources and trying to build. 107 108 FAILS=0 109 SKIP=0 110 if [ ${SKIP_FAILURES} -eq 1 ]; then 111 ${REG_CHECKFAIL} ${TEST_ID} 112 if [ $? -eq 0 ]; then 113 msg 1 "skipping ${TEST_ID}; it is a known build failure" 114 FAILS=1 115 SKIP=1 116 fi 117 fi 118 119 if [ ${FAILS} -eq 0 ]; then 120 ${REG_UPDATE} ${TEST_ID} || error "source update failed for ${TEST_ID}" 121 ${REG_BUILD} ${TEST_ID} 122 if [ $? -ne 0 ]; then 123 FAILS=1 124 msg 1 "build failed for ${TEST_ID}" 125 if [ ${SKIP_FAILURES} -eq 1 ]; then 126 ${REG_RECORDFAIL} ${TEST_ID} 127 fi 128 fi 129 fi 130 131 if [ ${FAILS} -eq 0 ]; then 132 ${REG_TEST} ${TEST_ID} 133 LATER=$? 134 if [ $LATER -ne 0 -a $LATER -ne 1 ]; then 135 msg 0 "unexpected test failure for ${TEST_ID}" 136 exit 1 137 fi 138 else 139 140 # The build failed, or this patch is already known to fail to build. 141 # If it's an endpoint, or if we don't have a way to recover from 142 # build failures, quit now. 143 144 if [ ${SKIP} -eq 0 ]; then 145 if [ "x${REG_NEWMID}" = "x" \ 146 -o ${TEST_ID} -eq ${LATER_THAN} \ 147 -o ${TEST_ID} -eq ${EARLIER_THAN} ]; then 148 error "build failed for ${TEST_ID}" 149 fi 150 fi 151 152 # Try to find a new patch to try within the current range. 153 154 FIRST_MID=`${REG_NEWMID} ${LATER_THAN} ${EARLIER_THAN}` 155 if [ ${FIRST_MID} -eq 0 ]; then 156 157 # The heuristics in the tool ran out of patches to try next; 158 # let the user handle it from here.+ 159 error "build failed for ${TEST_ID}, could not find new candidate" 160 fi 161 msg 1 "using ${FIRST_MID}, between ${LATER_THAN} and ${EARLIER_THAN}" 162 fi 163 164 # Return with a valid LATER value or a new ID to try in FIRST_MID. 165 } 166 167 # Get the number of a patch within the range. It's not actually the 168 # middle one, but the one that might minimize the number of checks. 169 170 get_mid_special() { 171 LOW=$1 172 HIGH=$2 173 174 let DIFF=HIGH-LOW 175 M=1 176 POWER2=1 177 while 178 [ $POWER2 -lt $DIFF ] 179 do 180 let M=POWER2 181 let POWER2=POWER2*2 182 done 183 let MID=LOW+M 184 } 185 186 # Get the number of the patch in the middle of the range. 187 188 get_mid () { 189 LOW=$1 190 HIGH=$2 191 192 let DIFF=HIGH-LOW 193 let M=DIFF/2 194 let MID=LOW+M 195 } 196 197 # Perform a binary search on patch identifiers within the range 198 # specified by the arguments. 199 200 search_patches () { 201 LOW=$1 202 HIGH=$2 203 204 # Get an identifier within the range. The user can override the 205 # initial mid patch if it is known to have problems, e.g., if a 206 # build fails for that patch. 207 208 if [ ${FIRST_MID} -ne 0 ]; then 209 MID=${FIRST_MID} 210 FIRST_MID=0 211 let DIFF=HIGH-LOW 212 else 213 get_mid $LOW $HIGH 214 fi 215 216 while [ ${DIFF} -gt 1 ]; do 217 TEST_ID="${MID}" 218 219 # Test it. 220 221 process_patch ${TEST_ID} 222 223 # FIRST_MID being set is a signal that the build failed and we 224 # should start over again. 225 226 test ${FIRST_MID} -ne 0 && return 227 228 # Narrow the search based on the outcome of testing TEST_ID. 229 230 if [ ${LATER} -eq 1 ]; then 231 msg 1 "search patches later than ${TEST_ID}" 232 LATER_THAN=${TEST_ID} 233 let LOW=MID 234 else 235 msg 1 "search patches earlier than ${TEST_ID}" 236 EARLIER_THAN=${TEST_ID} 237 let HIGH=MID 238 fi 239 240 get_mid $LOW $HIGH 241 done 242 } 243 244 ######################################################################## 245 # Main program (so to speak) 246 ######################################################################## 247 248 # The error function uses this. 249 250 VALID_RANGE=0 251 252 # Process the configuration file. 253 254 if [ $# != 1 ]; then 255 echo Usage: $0 config_file 256 exit 1 257 fi 258 259 CONFIG=${1} 260 if [ ! -f ${CONFIG} ]; then 261 error "configuration file ${CONFIG} does not exist" 262 fi 263 264 # OK, the config file exists. Source it, make sure required parameters 265 # are defined and their files exist, and give default values to optional 266 # parameters. 267 268 . ${CONFIG} 269 270 test "x${REG_UPDATE}" = "x" && error "REG_UPDATE is not defined" 271 test "x${REG_BUILD}" = "x" && error "REG_BUILD is not defined" 272 test "x${REG_TEST}" = "x" && error "REG_TEST is not defined" 273 test -x ${REG_TEST} || error "REG_TEST is not an executable file" 274 test "x${SKIP_LOW}" = "x" && SKIP_LOW=0 275 test "x${SKIP_HIGH}" = "x" && SKIP_HIGH=0 276 test "x${VERBOSITY}" = "x" && VERBOSITY=0 277 test "x${REG_FINISH}" = "x" && REG_FINISH=true 278 test "x${REG_REPORT}" = "x" && REG_REPORT=true 279 280 msg 2 "LOW_PATCH = ${LOW_PATCH}" 281 msg 2 "HIGH_PATCH = ${HIGH_PATCH}" 282 msg 2 "REG_UPDATE = ${REG_UPDATE}" 283 msg 2 "REG_BUILD = ${REG_BUILD}" 284 msg 2 "REG_TEST = ${REG_TEST}" 285 msg 2 "REG_NEWMID = ${REG_NEWMID}" 286 msg 2 "SKIP_LOW = ${SKIP_LOW}" 287 msg 2 "SKIP_HIGH = ${SKIP_HIGH}" 288 msg 2 "FIRST_MID = ${FIRST_MID}" 289 msg 2 "VERBOSITY = ${VERBOSITY}" 290 291 # If REG_NEWMID was defined, assume that we're skipping known failures 292 # and adding to the list for new failures. If the list of failures 293 # doesn't exist, create it. We use a different flag, SKIP_FAILURES, 294 # to make it easier to separate the flag from REG_NEWMID if we want 295 # to change the usage later. 296 297 if [ "x${REG_NEWMID}" != "x" ]; then 298 touch ${REG_FAILLIST} 299 SKIP_FAILURES=1 300 else 301 SKIP_FAILURES=0 302 fi 303 304 # If FIRST_MID was defined, make sure it's in the range. 305 306 if [ "x${FIRST_MID}" != "x" ]; then 307 test ${FIRST_MID} -le ${LOW_PATCH} && \ 308 error "FIRST_MID id is lower than LOW_PATCH" 309 test ${FIRST_MID} -ge ${HIGH_PATCH} && \ 310 error "FIRST_MID is higher than HIGH_PATCH" 311 else 312 FIRST_MID=0 313 fi 314 315 # Keep track of the bounds of the range where the test behavior changes. 316 317 LATER_THAN=${LOW_PATCH} 318 EARLIER_THAN=${HIGH_PATCH} 319 LATER=1 320 321 msg 1 "LATER_THAN = ${LATER_THAN}" 322 msg 1 "EARLIER_THAN = ${EARLIER_THAN}" 323 324 # Verify that the range isn't backwards. 325 326 test ${LOW_PATCH} -lt ${HIGH_PATCH} || \ 327 error "patch identifier range is backwards" 328 329 # Verify that the first and last patches in the range get the results we 330 # expect. If not, quit, because any of several things could be wrong. 331 332 if [ ${SKIP_HIGH} -eq 0 ]; then 333 process_patch ${EARLIER_THAN} 334 test ${LATER} -ne 0 && \ 335 error "unexpected result for high patch ${EARLIER_THAN}" 336 msg 1 "result for high patch ${EARLIER_THAN} is as expected" 337 fi 338 339 if [ ${SKIP_LOW} -eq 0 ]; then 340 process_patch ${LATER_THAN} 341 test ${LATER} -ne 1 && \ 342 error "unexpected result for low patch ${LATER_THAN}" 343 msg 1 "result for low patch ${LATER_THAN} is as expected" 344 fi 345 346 # Search within the range, now that we know that the end points are valid. 347 # If the build failed then FIRST_MID is set to a new patch to try. 348 349 VALID_RANGE=1 350 while true; do 351 search_patches ${LATER_THAN} ${EARLIER_THAN} 352 test ${FIRST_MID} -eq 0 && break 353 done 354 355 # Report where the test behavior changes. 356 357 echo "Test result changes with id ${EARLIER_THAN}" 358 ${REG_REPORT} ${EARLIER_THAN} 359 360 # Invoke the optional script to verify the result and report additional 361 # information about changes between the two patches. 362 363 ${REG_FINISH} ${LATER_THAN} ${EARLIER_THAN} 364
Indexes created Sun Apr 12 00:22:20 UTC 2026