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  22 .TH check_rtime 1ONBLD "09 March 2010"
  23 .SH NAME
  24 .I check_rtime
  25 \- check ELF runtime attributes
  26 .SH SYNOPSIS
  27 \fBcheck_rtime [-imosv] [-D depfile | -d depdir] [-E errfile] [-e exfile] [-f listfile] [-I infofile] [-w outdir] file | dir, ...\fP
  28 .LP
  29 .SH DESCRIPTION
  30 .IX "OS-Net build tools" "check_rtime" "" "\fBcheck_rtime\fP"
  31 .LP
  32 .I check_rtime
  33 attempts to check a number of ELF runtime attributes
  34 for consistency with common build rules.
  35 These checks involve running \fBldd(1)\fP and
  36 \fBelfdump(1)\fP against a family of dynamic objects.
  37 A dynamic object can be defined explicitly as a \fIfile\fP
  38 or multiple dynamic objects can be located under the directory \fIdir\fP.
  39 .LP
  40 .I check_rtime
  41 is typically called from \fBnightly(1ONBLD)\fP when the \fB-r\fP
  42 option is in effect. In this case the dynamic objects under
  43 the associated \fIproto\fP area (\fB$ROOT\fP) are checked.
  44 .I check_rtime
  45 can also be run standalone against any set of dynamic objects.
  46 .LP
  47 .I check_rtime
  48 uses \fBldd(1)\fP to verify dependencies. This implies that
  49 by default any object inspected will bind to its dependencies
  50 as they are found in the \fBunderlying\fP system.  Use of the \fB-D\fP, \fB-d\fP
  51 option, or the existence of the environment variables
  52 \fB$CODEMGR_WS/$ROOT\fP instruct
  53 .I check_rtime
  54 to establish an alternative dependency mapping using
  55 runtime configuration files generated with \fBcrle(1)\fP.
  56 .LP
  57 .I check_rtime
  58 uses \fBldd(1)\fP to completely relocate any dynamic
  59 object and thus detect missing dependencies, unsatisfied
  60 symbol relocations, unused and unreferenced dependencies. These checks
  61 are carried out for the following reasons:
  62 .TP 4
  63 \(bu
  64 An object that cannot find its dependencies may fail to load
  65 at runtime.  This error condition often goes unnoticed
  66 because the existing use of the object is as a dependency itself,
  67 and the objects' dependencies are already satisfied by the
  68 caller.  However, if the object itself is unable to satisfy its
  69 dependencies, its use in new environments may be compromised.
  70 .sp
  71 A missing or erroneous \fBrunpath\fP is the typical reason why
  72 an object can not locate its dependencies.  Use of the link-editors
  73 \fB-zdefs\fP option when building a shared object ensures required
  74 dependencies are established.  This flag is inherited from
  75 \fB$(DYNFLAGS)\fP in \fIlib/Makefile.lib\fP. Missing dependencies
  76 are displayed as:
  77 .sp
  78 .RS 6
  79 foo: bar.so.1 => (file not found)  <no -zdefs?>
  80 .RE
  81 .TP
  82 \(bu
  83 Unsatisfied symbol relocations indicate that some thread of
  84 execution through the object will fail when it is unable to
  85 locate a referenced symbol.
  86 .sp
  87 A missing, or mismatched version of a dependency is the typical
  88 reason for unsatisfied symbol relocations (see missing dependency
  89 discussion above). Unsatisfied symbol relocations are displayed as:
  90 .sp
  91 .RS 6
  92 foo: symbol not found: bar  <no -zdefs?>
  93 .RE
  94 .RS 4
  95 .sp
  96 Note: Shared objects can make reference to symbol definitions
  97 that are expected to be defined by the caller. To indicate that
  98 such symbols are not undefined in the usual sense, you must
  99 specify these symbols in a \fImapfile\fP, using the \fBEXTERN\fP
 100 or \fBPARENT\fP symbol attribute. Without these symbol attributes,
 101 \fBldd(1)\fP is unable to determine the symbols special nature, and
 102 .I check_rtime
 103 will report these symbols as undefined. 
 104 .RE
 105 .TP
 106 \(bu
 107 Unused dependencies are wasteful at runtime, as they take time to
 108 load and relocate, but will not be used by the calling object.  They
 109 also result in unnecessary processing at link-edit time.
 110 .sp
 111 Dependency lists (typically defined via \fB$(LDLIBS)\fP)
 112 that have been yanked-and-put
 113 between \fIMakefiles\fP without verifying their need, are a typical
 114 reason why unused dependencies exist.  Unused dependencies are
 115 displayed as:
 116 .sp
 117 .RS 6
 118 foo: unused object=bar.so.1  <remove lib or -zignore?>
 119 .RE
 120 .TP
 121 \(bu
 122 Unreferenced dependencies are also wasteful at runtime, although not
 123 to the extent of unused dependencies.  They also result in unnecessary
 124 processing at link-edit time.
 125 .sp
 126 Unreferenced dependency removal guards against a dependency becoming
 127 unused when combined with
 128 different objects, or as the other object dependencies evolve.
 129 Unreferenced dependencies are displayed as:
 130 .sp
 131 .RS 6
 132 foo: unreferenced object=bar.so.1;  \\
 133 .br
 134     unused dependency of libfoo.so.1  \\
 135 .br
 136     <remove lib or -zignore?>
 137 .RE
 138 .RS 4
 139 .sp
 140 See also the section ENVIRONMENT VARIABLES.
 141 .RE
 142 .TP
 143 \(bu
 144 Unused search paths are wasteful at runtime.
 145 Unused search paths are displayed as:
 146 .sp
 147 .RS 6
 148 foo: unused search path=/usr/foo/lib  \\
 149 .br
 150     (RUNPATH/RPATH from file libfoo.so.1)  \\
 151 .br
 152     <remove search path?>
 153 .RE
 154 .LP
 155 .I check_rtime
 156 uses \fBelfdump(1)\fP to look for a concatenated relocation
 157 section in shared objects, the existence of text relocations,
 158 whether debugging or symbol table information exists, whether
 159 applications have a non-executable stack defined, duplicate
 160 entries in the symbol sorting sections, and for direct bindings.
 161 These checks are carried out for the following reasons:
 162 .TP 4
 163 \(bu
 164 A concatenated relocation section (\fI.SUNW_reloc\fP)
 165 provides optimal symbol table
 166 access at runtime, and thus reduces the overhead of relocating
 167 the shared object.  In past releases, the link-edit of a dynamic object with
 168 the \fB-z combreloc\fP option was required to generate a combined
 169 relocation section.  However, with the integration of 6642769, this section
 170 combination is a default behavior of the link-editor.
 171 .sp
 172 In past releases, not inheriting \fB$(DYNFLAGS)\fP from
 173 \fIlib/Makefile.lib\fP was the typical reason for not having a
 174 concatenated relocation section. The misguided use of the
 175 \fB-z nocombreloc\fP option will also prevent the creation of a
 176 concatenated relocation section. A missing concatenated relocation section
 177 is displayed as:
 178 .sp
 179 .RS 6
 180 foo: .SUNW_reloc section missing  <no -zcombreloc?>
 181 .RE
 182 .TP
 183 \(bu
 184 Text relocations result in impure text segments.  As text segments
 185 are typically read-only, they can be shared between numerous processes.
 186 If they must be updated as part of the relocation then the updated
 187 pages become unsharable and swap space must be allocated to back
 188 these pages.  These events consume unnecessary system resources and
 189 reduce overall system performance.
 190 .sp
 191 Not inheriting the \fB$(PICS)\fP
 192 rules from \fIlib/Makefile.lib\fP is the typical reason for having
 193 non-pic code in shared objects.  Text relocations are displayed as:
 194 .sp
 195 .RS 6
 196 foo: TEXTREL .dynamic tag  <no -Kpic?>
 197 .RE
 198 .TP
 199 \(bu
 200 Debugging information is unnecessary in released objects.  Although
 201 extensive when compiled \fB-g\fP, small quantities of debugging
 202 information are stored in \fI.stabs\fP sections under normal
 203 compilations.  This debugging information is geared towards aiding
 204 debuggers locate relocatable objects associated with the dynamic
 205 objects being debugged.  As relocatable objects aren't made available
 206 as part of a software release this information has no use.
 207 .sp
 208 Not inheriting the correct \fB$(LDFLAGS)\fP from \fIcmd/Makefile.cmd\fP
 209 (which asserts \fP-s\fP), or \fB$(POST_PROCESS_SO)\fP (which asserts
 210 \fIstrip -x\fP) are typical reasons for not removing debugging
 211 information.  Note, removal of debugging information is only enabled
 212 for release builds. The existence of debugging information is displayed as:
 213 .sp
 214 .RS 6
 215 foo: debugging sections should be deleted  \\
 216 .br
 217     <no strip -x?>
 218 .RE
 219 .TP
 220 \(bu
 221 All objects should retain their full \fI.symtab\fP symbol table.
 222 Although this consumes disk space, it provides for more extensive stack
 223 tracing when debugging user applications.
 224 .sp
 225 Hard coding a \fI-s\fP flag with \fB$(LDFLAGS)\fP or
 226 \fB$(DYNFLAGS)\fP is the typical
 227 reason for symbol tables being removed.
 228 Objects that do not contain a symbol table are displayed as:
 229 .sp
 230 .RS 6
 231 foo.so.1: symbol table should not be stripped  \\
 232 .br
 233     <remove -s?>
 234 .RE
 235 .TP
 236 \(bu
 237 Applications should have a non-executable stack defined to make
 238 them less vulnerable to buffer overflow attacks.
 239 .sp
 240 Not inheriting the \fB$(LDFLAGS)\fP macro in \fIcmd/Makefile.cmd\fP
 241 is the typical reason for not having a non-executable stack definition.
 242 Applications without this definition are displayed as:
 243 .sp
 244 .RS 6
 245 foo: application requires non-executable stack \\
 246 .br
 247         <no -Mmapfile_noexstk?>
 248 .RE
 249 .sp
 250 .TP
 251 \(bu
 252 x86 applications should have a non-executable data segment defined to make
 253 them less vulnerable to buffer overflow attacks.
 254 .sp
 255 Not inheriting the \fB$(LDFLAGS)\fP macro in \fIcmd/Makefile.cmd\fP
 256 is the typical reason for not having a non-executable data definition.
 257 Applications without this definition are displayed as:
 258 .sp
 259 .RS 6
 260 foo: application requires non-executable data \\
 261 .br
 262         <no -Mmapfile_noexdata?>
 263 .RE
 264 .sp
 265 .TP
 266 \(bu
 267 Solaris ELF files contain symbol sort sections used by DTrace to
 268 map addresses in memory to the related function or variable symbols. There
 269 are two such sections, \fI.SUNW_dynsymsort\fP for
 270 regular symbols, and \fI.SUNW_dyntlssort\fP for thread-local
 271 symbols. To ensure that the best names are shown for each
 272 such address, and that the same name is given across Solaris releases,
 273 .I check_rtime
 274 enforces the rule that only one symbol can appear in the sort sections for
 275 any given address.
 276 There are two common ways in which multiple symbols 
 277 or a given address occur in the ON distribution. The first is from
 278 code written in assembly language. The second is as a 
 279 result of using \fB#pragma weak\fP in C to create weak symbols. The
 280 best solution to this
 281 situation is to modify the code to avoid symbol aliasing. Alternatively,
 282 the \fBNODYNSORT\fP mapfile attribute can be used to eliminate the unwanted
 283 symbol.
 284 .sp
 285 Duplicate entries in a symbol sort section are
 286 displayed in one of the following ways, depending on
 287 whether the section is for regular or thread-local symbols:
 288 .sp
 289 .RS 6
 290 foo: .SUNW_dynsymsort: duplicate ADDRESS: sym1, sym2
 291 .br
 292 foo: .SUNW_dyntlssort: duplicate OFFSET: sym1, sym2
 293 .RE
 294 .sp
 295 .TP
 296 \(bu
 297 \fBOSNet\fP dynamic ELF objects are expected to employ direct bindings whenever
 298 feasible.  This runtime binding technique helps to avoid accidental
 299 interposition problems, and provides a more optimal
 300 runtime symbol search model.
 301 .sp
 302 Not inheriting the correct \fB$(LDFLAGS)\fP from \fIcmd/Makefile.cmd\fP,
 303 or the correct \fB$(DYNFLAGS)\fP from \fIlib/Makefile.lib\fP, are the
 304 typical reasons for not enabling direct bindings. Dynamic objects that
 305 do not contain direct binding information are displayed as:
 306 .sp
 307 .RS 6
 308 foo: object has no direct bindings \\
 309 .br
 310         <no -B direct or -z direct?>
 311 .RE
 312 
 313 .sp
 314 .LP
 315 .I check_rtime also
 316 uses \fBelfdump(1)\fP
 317 to display useful dynamic entry information under the \fB-i\fP option.
 318 This doesn't necessarily indicate an error condition, but
 319 provides information that is often useful for gatekeepers to track
 320 changes in a release.  Presently the information listed is:
 321 .TP
 322 \(bu
 323 Runpaths are printed for any dynamic object.  This is a historic
 324 sanity check to insure compiler supplied runpaths (typically from \fBCC\fP)
 325 are not recorded in any objects.  Runpaths are displayed as:
 326 .sp
 327 .RS 6
 328 foo: RPATH=/usr/bar/lib
 329 .RE
 330 .TP
 331 \(bu
 332 Needed dependencies are printed for any dynamic object.
 333 In the freeware world this often helps the introducer of a new
 334 shared object discover that an existing binary has become its
 335 consumer, and thus that binaries package dependencies may require updating.
 336 Dependencies are printed as:
 337 .sp
 338 .RS 6
 339 foo: NEEDED=bar.so.1
 340 .RE
 341 .sp
 342 .LP
 343 .I check_rtime
 344 uses \fBmcs(1)\fP to inspect an object's \fI.comment\fP section.
 345 During development, this section contains numerous file identifiers
 346 marked with the tag "\fB@(#)\fP".  For release builds these sections
 347 are deleted and rewritten under control of the \fB$(POST_PROCESS)\fP
 348 macro to produce a common release identifier.  This identifier
 349 typically consists of three lines including a single comment starting
 350 with the string "\fB@(#) SunOS\fP".  If this common identifier isn't
 351 found the following diagnostic is generated:
 352 .sp
 353 .RS 6
 354 foo: non-conforming mcs(1) comment  <no $(POST_PROCESS)?>
 355 .RE
 356 .sp
 357 .LP
 358 .I check_rtime
 359 uses \fBpvs(1)\fP to display version definitions under the \fB-v\fP option.
 360 Each symbol defined by the object is shown along with the version it belongs to.
 361 Changes to the symbols defined by an object, or the versions they belong to,
 362 do not necessarily indicate an error condition, but
 363 provides information that is often useful for gatekeepers to track
 364 changes in a release.
 365 .RE
 366 .sp
 367 .LP
 368 .SH OPTIONS
 369 .LP
 370 The following options are supported:
 371 .TP 4
 372 .B \-D depfile
 373 Use \fIdepfile\fP to generate an alternative dependency mapping.
 374 \fIdepfile\fP must be created by '\fBfind_elf -r\fP'.
 375 The \fB-D\fP and \fB-d\fP options are mutually exclusive.
 376 .TP
 377 .B \-d depdir
 378 Use \fIdepdir\fP to generate an alternative dependency mapping.
 379 \fBfind_elf(1ONBLD)\fP is used to locate the ELF sharable objects for
 380 which alternative mappings are required. The \fB-D\fP and \fB-d\fP options
 381 are mutually exclusive.
 382 .TP 4
 383 .B \-E errfile
 384 Direct error messages for the analyzed objects to \fIerrfile\fP instead 
 385 of stdout.
 386 .TP 4
 387 .B \-e exfile
 388 An exception file is used to exclude objects from
 389 the usual rules. See EXCEPTION FILE FORMAT.
 390 .TP
 391 .B \-f listfile
 392 Normally,
 393 .I interface_check
 394 runs
 395 .I find_elf
 396 to locate the ELF objects to analyze. The \fB-f\fP option can be
 397 used to instead provide a file containing the list of objects to
 398 analyze, in the format produced by '\fBfind_elf -r\fP'.
 399 .TP
 400 .B -I infofile
 401 Direct informational messages (\fB-i\fP, and \fB-v\fP options) for the
 402 analyzed objects to \fIinfofile\fP instead of stdout.
 403 .TP
 404 .B \-i
 405 Provide dynamic entry information.  Presently only dependencies and
 406 runpaths are printed.
 407 .TP
 408 .B \-m
 409 Enable \fBmcs(1)\fP checking.
 410 .TP
 411 .B \-o
 412 Produce a one-line output for each condition discovered, prefixed
 413 by the objects name.  This output style is more terse, but is
 414 more appropriate for sorting and diffing with previous build results.
 415 .TP
 416 .B \-s
 417 Determine whether \fI.stabs\fP sections exist.
 418 .TP
 419 .B \-v
 420 Provide version definition information. Each symbol defined by the object
 421 is printed along with the version it is assigned to.
 422 .TP
 423 .B -w outdir
 424 Interpret the paths of all input and output files relative to \fIoutdir\fP.
 425 .LP
 426 .SH EXCEPTION FILE FORMAT
 427 Exceptions to the rules enforced by
 428 .I check_rtime
 429 are specified using an exception file. The \fB-e\fP option is used to
 430 specify an explicit exception file. Otherwise, if used in an activated
 431 workspace, the default exception file is
 432 $CODEMGR_WS/exception_list/check_rtime
 433 if that file exists. If not used in an activated workspace, or if
 434 $CODEMGR_WS/exception_list/check_rtime does not exist,
 435 .I check_rtime
 436 will use
 437 .I /opt/onbld/etc/exception_list/check_rtime
 438 as a fallback default exception file.
 439 .p
 440 To run
 441 .I check_rtime
 442 without applying exceptions, specify \fB-e\fP with a value of /dev/null.
 443 .P
 444 A '#' character at the beginning of a line, or at any point in
 445 a line when preceded by whitespace, introduces a comment. Empty lines, 
 446 and lines containing only comments, are ignored by
 447 .I check_rtime.
 448 Exceptions are specified as space separated keyword, and \fBperl(1)\fP
 449 regular expression:
 450 .sp
 451 .in +4
 452 .nf
 453 keyword  perl-regex
 454 .fi
 455 .in -4
 456 .sp
 457 Since whitespace is used as a separator, the regular
 458 expression cannot itself contain whitespace. Use of the \\s character
 459 class to represent whitespace within the regular expression is recommended.
 460 Before the perl regular expression is used, constructs of the form
 461 MACH(dir) are expanded into a regular expression that matches the directory
 462 given, as well as any 64-bit architecture subdirectory that
 463 might be present (i.e. amd64, sparcv9). For instance, MACH(lib) will
 464 match any of the following:
 465 .sp
 466 .in +4
 467 .nf
 468 lib
 469 lib/amd64
 470 lib/sparcv9
 471 .fi
 472 .in -4
 473 .sp
 474 The exceptions understood by
 475 .I check_rtime
 476 are:
 477 .sp
 478 .ne 2
 479 .mk
 480 .na
 481 \fBEXEC_DATA\fR
 482 .ad
 483 .RS 17n
 484 .rt
 485 .sp
 486 Executables that are not required to have non-executable writable
 487 data segments
 488 .RE
 489 
 490 .sp
 491 .ne 2
 492 .mk
 493 .na
 494 \fBEXEC_STACK\fR
 495 .ad
 496 .RS 17n
 497 .rt
 498 .sp
 499 Executables that are not required to have a non-executable stack
 500 .RE
 501 
 502 .sp
 503 .ne 2
 504 .mk
 505 .na
 506 \fBNOCRLEALT\fR
 507 .ad
 508 .RS 17n
 509 .rt
 510 .sp
 511 Objects that should be skipped when building the alternative dependency 
 512 mapping via the \fB-d\fP option.
 513 .RE
 514 
 515 .sp
 516 .ne 2
 517 .mk
 518 .na
 519 \fBNODIRECT\fR
 520 .ad
 521 .RS 17n
 522 .rt
 523 .sp
 524 Directories and files that are allowed to have no direct bound symbols.
 525 .RE
 526 
 527 .sp
 528 .ne 2
 529 .mk
 530 .na
 531 \fBNOSYMSORT\fR
 532 .ad
 533 .RS 17n
 534 .rt
 535 .sp
 536 Files for which we skip checking of duplicate addresses in the
 537 symbol sort sections.
 538 .RE
 539 
 540 .sp
 541 .ne 2
 542 .mk
 543 .na
 544 \fBOLDDEP\fR
 545 .ad
 546 .RS 17n
 547 .rt
 548 .sp
 549 Objects that used to contain system functionality that has since
 550 migrated to libc. We preserve these libraries as pure filters for
 551 backward compatibility but nothing needs to link to them.
 552 .RE
 553 
 554 .sp
 555 .ne 2
 556 .mk
 557 .na
 558 \fBSKIP\fR
 559 .ad
 560 .RS 17n
 561 .rt
 562 .sp
 563 Directories and/or individual objects to skip. Note that SKIP should be
 564 a last resort, used only when one of the other exceptions will not suffice.
 565 .RE
 566 
 567 .sp
 568 .ne 2
 569 .mk
 570 .na
 571 \fBSTAB\fR
 572 .ad
 573 .RS 17n
 574 .rt
 575 .sp
 576 Objects that are allowed to contain debugging information (stabs).
 577 .RE
 578 
 579 .sp
 580 .ne 2
 581 .mk
 582 .na
 583 \fBTEXTREL\fR
 584 .ad
 585 .RS 17n
 586 .rt
 587 .sp
 588 Objects for which we allow relocations to the text segment.
 589 .RE
 590 
 591 .sp
 592 .ne 2
 593 .mk
 594 .na
 595 \fBUNDEF_OBJ\fR
 596 .ad
 597 .RS 17n
 598 .rt
 599 .sp
 600 Objects that are allowed to be unreferenced.
 601 .RE
 602 
 603 .sp
 604 .ne 2
 605 .mk
 606 .na
 607 \fBUNDEF_REF\fR
 608 .ad
 609 .RS 17n
 610 .rt
 611 .sp
 612 Objects that are allowed undefined references.
 613 .RE
 614 
 615 .sp
 616 .ne 2
 617 .mk
 618 .na
 619 \fBUNUSED_DEPS\fR
 620 .ad
 621 .RS 17n
 622 .rt
 623 .sp
 624 Objects that are allowed to have unused dependencies.
 625 .RE
 626 
 627 .sp
 628 .ne 2
 629 .mk
 630 .na
 631 \fBUNUSED_OBJ\fR
 632 .ad
 633 .RS 17n
 634 .rt
 635 .sp
 636 Objects that are always allowed to be unused dependencies.
 637 .RE
 638 
 639 .sp
 640 .ne 2
 641 .mk
 642 .na
 643 \fBUNUSED_RPATH\fR
 644 .ad
 645 .RS 17n
 646 .rt
 647 .sp
 648 Objects that are allowed to have unused runpath directories.
 649 .RE
 650 
 651 .LP
 652 .SH ALTERNATIVE DEPENDENCY MAPPING
 653 .I check_rtime
 654 was primarily designed to process a nightly builds \fB$ROOT\fP
 655 hierarchy. It is often the case that objects within this hierarchy
 656 must bind to dependencies within the same hierarchy to satisfy
 657 their requirements.
 658 .LP
 659 To achieve this,
 660 .I check_rtime
 661 uses the shared objects specified with the \fB-D\fP or \fB-d\fP options.
 662 If neither option is specified, and the \fB$CODEMGR_WS\fP and \fB$ROOT\fP
 663 environment variables are defined, the proto area for the workspace
 664 is used. The objects found are used
 665 to create runtime configuration files via \fBcrle(1)\fP, that establish
 666 the new shared objects as alternatives to their underlying system location.
 667 .I check_rtime
 668 passes these configuration files as \fBLD_CONFIG\fP environment
 669 variable settings to \fBldd(1)\fP using its \fB-e\fP option.
 670 .LP
 671 The effect of these configuration files is that the execution of an
 672 object under \fBldd(1)\fP will bind to the dependencies defined as
 673 alternatives.  Simply put, an object inspected in the \fIproto\fP
 674 area will bind to its dependencies found in the \fIproto\fP area.
 675 Dependencies that have no alternative mapping will continue to
 676 bind to the underlying system.
 677 .LP
 678 .SH ENVIRONMENT VARIABLES
 679 .LP
 680 When the \fB-D\fP or \fB-d\fP option isn't in use,
 681 .I check_rtime
 682 uses the following environment variables to
 683 establish an alternative dependency mapping:
 684 .LP
 685 .B CODEMGR_WS
 686 .RS 4
 687 The root of your workspace, which is the directory
 688 containing \fICodemgr_wsdata\fP. Existence of this environment variable
 689 indicates that \fB$ROOT\fP should be investigated.
 690 .RE
 691 .LP
 692 .B ROOT
 693 .RS 4
 694 Root of the \fIproto\fP area of your workspace. Any shared objects
 695 under this directory will be used to establish an alternative dependency
 696 mapping.
 697 .RE
 698 .sp
 699 If \fBldd(1)\fP supports the \fB-U\fP option, it will be used to determine
 700 any unreferenced dependencies.  Otherwise \fBldd(1)\fP uses the older
 701 \fB-u\fP option which only detects unused references.  If the following
 702 environment variable exists, and indicates an earlier release than \fB5.10\fP
 703 then \fBldd(1)\fP also falls back to using the \fB-u\fP option.
 704 .RE
 705 .LP
 706 .B RELEASE
 707 .RS 4
 708 The release version number of the environment being built.
 709 .RE
 710 .SH ERROR CONDITIONS
 711 .LP
 712 Inspection of an object with \fBldd(1)\fP assumes it is compatible
 713 with the machine on which
 714 .I check_rtime
 715 is being run.  Incompatible objects such as a 64-bit object encountered on
 716 a 32-bit system, or an i386 object encountered on a sparc system,
 717 can not be fully inspected.  These objects are displayed as:
 718 .sp
 719 .RS 4
 720 foo: has wrong class or data encoding
 721 .RE
 722 .LP
 723 .SH FILES
 724 .LP
 725 .RS 5
 726 $CODEMGR_WS/exception_list/check_rtime
 727 /opt/onbld/etc/exception_list/check_rtime
 728 .SH SEE ALSO
 729 .B crle(1),
 730 .B elfdump(1),
 731 .B find_elf(1ONBLD),
 732 .B ldd(1),
 733 .B ld.so.1(1),
 734 .B mcs(1).