1 '\" te 2 .\" Copyright 1989 AT&T 3 .\" Copyright (c) 2009, Sun Microsystems, Inc. All Rights Reserved 4 .\" Copyright (c) 2012, Joyent, Inc. All Rights Reserved 5 .\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License. You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. 6 .\" See the License for the specific language governing permissions and limitations under the License. When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with 7 .\" the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner] 8 .TH LD 1 "Sep 10, 2013" 9 .SH NAME 10 ld \- link-editor for object files 11 .SH SYNOPSIS 12 .LP 13 .nf 14 \fBld\fR [\fB-32\fR | \fB-64\fR] [\fB-a\fR | \fB-r\fR] [\fB-b\fR] [\fB-B\fRdirect | nodirect] 15 [\fB-B\fR dynamic | static] [\fB-B\fR eliminate] [\fB-B\fR group] [\fB-B\fR local] 16 [\fB-B\fR reduce] [\fB-B\fR symbolic] [\fB-c\fR \fIname\fR] [\fB-C\fR] [\fB-d\fR y | n] 17 [\fB-D\fR \fItoken\fR,...] [\fB-e\fR \fIepsym\fR] [\fB-f\fR \fIname\fR | \fB-F\fR \fIname\fR] [\fB-G\fR] [\fB-h\fR \fIname\fR] 18 [\fB-i\fR] [\fB-I\fR \fIname\fR] [\fB-l\fR \fIx\fR] [\fB-L\fR \fIpath\fR] [\fB-m\fR] [\fB-M\fR \fImapfile\fR] 19 [\fB-N\fR \fIstring\fR] [\fB-o\fR \fIoutfile\fR] [\fB-p\fR \fIauditlib\fR] [\fB-P\fR \fIauditlib\fR] 20 [\fB-Q\fR y | n] [\fB-R\fR \fIpath\fR] [\fB-s\fR] [\fB-S\fR \fIsupportlib\fR] [\fB-t\fR] 21 [\fB-u\fR \fIsymname\fR] [\fB-V\fR] [\fB-Y P\fR\fI,dirlist\fR] [\fB-z\fR absexec] 22 [\fB-z\fR allextract | defaultextract | weakextract ] [\fB-z\fR altexec64] 23 [\fB-z\fR aslr[=\fIstate\fR]] [\fB-z\fR assert-deflib] [ \fB-z\fR assert-deflib=\fIlibname\fR] 24 [\fB-z\fR combreloc | nocombreloc ] [\fB-z\fR defs | nodefs] 25 [\fB-z\fR direct | nodirect] [\fB-z\fR endfiltee] 26 [\fB-z\fR fatal-warnings | nofatal-warnings ] [\fB-z\fR finiarray=\fIfunction\fR] 27 [\fB-z\fR globalaudit] [\fB-z\fR groupperm | nogroupperm] 28 [\fB-z\fR guidance[=\fIid1\fR,\fIid2\fR...] [\fB-z\fR help ] 29 [\fB-z\fR ignore | record] [\fB-z\fR initarray=\fIfunction\fR] [\fB-z\fR initfirst] 30 [\fB-z\fR interpose] [\fB-z\fR lazyload | nolazyload] 31 [\fB-z\fR ld32=\fIarg1\fR,\fIarg2\fR,...] [\fB-z\fR ld64=\fIarg1\fR,\fIarg2\fR,...] 32 [\fB-z\fR loadfltr] [\fB-z\fR muldefs] [\fB-z\fR nocompstrtab] [\fB-z\fR nodefaultlib] 33 [\fB-z\fR nodelete] [\fB-z\fR nodlopen] [\fB-z\fR nodump] [\fB-z\fR noldynsym] 34 [\fB-z\fR nopartial] [\fB-z\fR noversion] [\fB-z\fR now] [\fB-z\fR origin] 35 [\fB-z\fR preinitarray=\fIfunction\fR] [\fB-z\fR redlocsym] [\fB-z\fR relaxreloc] 36 [\fB-z\fR rescan-now] [\fB-z\fR recan] [\fB-z\fR rescan-start \fI\&...\fR \fB-z\fR rescan-end]] 37 [\fB-z\fR target=sparc|x86] [\fB-z\fR text | textwarn | textoff] 38 [\fB-z\fR verbose] [\fB-z\fR wrap=\fIsymbol\fR] \fIfilename\fR... 39 .fi 40 41 .SH DESCRIPTION 42 .sp 43 .LP 44 The link-editor, \fBld\fR, combines relocatable object files by resolving 45 symbol references to symbol definitions, together with performing relocations. 46 \fBld\fR operates in two modes, static or dynamic, as governed by the \fB-d\fR 47 option. In all cases, the output of \fBld\fR is left in the file \fBa.out\fR by 48 default. See NOTES. 49 .sp 50 .LP 51 In dynamic mode, \fB-dy\fR, the default, relocatable object files that are 52 provided as arguments are combined to produce an executable object file. This 53 file is linked at execution with any shared object files that are provided as 54 arguments. If the \fB-G\fR option is specified, relocatable object files are 55 combined to produce a shared object. Without the \fB-G\fR option, a dynamic 56 executable is created. 57 .sp 58 .LP 59 In static mode, \fB-dn\fR, relocatable object files that are provided as 60 arguments are combined to produce a static executable file. If the \fB-r\fR 61 option is specified, relocatable object files are combined to produce one 62 relocatable object file. See \fBStatic Executables\fR. 63 .sp 64 .LP 65 Dynamic linking is the most common model for combining relocatable objects, and 66 the eventual creation of processes within Solaris. This environment tightly 67 couples the work of the link-editor and the runtime linker, \fBld.so.1\fR(1). 68 Both of these utilities, together with their related technologies and 69 utilities, are extensively documented in the \fILinker and Libraries Guide\fR. 70 .sp 71 .LP 72 If any argument is a library, \fBld\fR by default searches the library exactly 73 once at the point the library is encountered on the argument list. The library 74 can be either a shared object or relocatable archive. See \fBar.h\fR(3HEAD)). 75 .sp 76 .LP 77 A shared object consists of an indivisible, whole unit that has been generated 78 by a previous link-edit of one or more input files. When the link-editor 79 processes a shared object, the entire contents of the shared object become a 80 logical part of the resulting output file image. The shared object is not 81 physically copied during the link-edit as its actual inclusion is deferred 82 until process execution. This logical inclusion means that all symbol entries 83 defined in the shared object are made available to the link-editing process. 84 See Chapter 4, \fIShared Objects,\fR in \fILinker and Libraries Guide\fR 85 .sp 86 .LP 87 For an archive library, \fBld\fR loads only those routines that define an 88 unresolved external reference. \fBld\fR searches the symbol table of the 89 archive library sequentially to resolve external references that can be 90 satisfied by library members. This search is repeated until no external 91 references can be resolved by the archive. Thus, the order of members in the 92 library is functionally unimportant, unless multiple library members exist that 93 define the same external symbol. Archive libraries that have interdependencies 94 can require multiple command line definitions, or the use of one of the 95 \fB-z\fR \fBrescan\fR options. See \fIArchive Processing\fR in \fILinker and 96 Libraries Guide\fR. 97 .sp 98 .LP 99 \fBld\fR is a cross link-editor, able to link 32-bit objects or 64-bit objects, 100 for Sparc or x86 targets. \fBld\fR uses the \fBELF\fR class and machine type of 101 the first relocatable object on the command line to govern the mode in which to 102 operate. The mixing of 32-bit objects and 64-bit objects is not permitted. 103 Similarly, only objects of a single machine type are allowed. See the 104 \fB-32\fR, \fB-64\fR and \fB-z target\fR options, and the \fBLD_NOEXEC_64\fR 105 environment variable. 106 .SS "Static Executables" 107 .sp 108 .LP 109 The creation of static executables has been discouraged for many releases. In 110 fact, 64-bit system archive libraries have never been provided. Because a 111 static executable is built against system archive libraries, the executable 112 contains system implementation details. This self-containment has a number of 113 drawbacks. 114 .RS +4 115 .TP 116 .ie t \(bu 117 .el o 118 The executable is immune to the benefits of system patches delivered as shared 119 objects. The executable therefore, must be rebuilt to take advantage of many 120 system improvements. 121 .RE 122 .RS +4 123 .TP 124 .ie t \(bu 125 .el o 126 The ability of the executable to run on future releases can be compromised. 127 .RE 128 .RS +4 129 .TP 130 .ie t \(bu 131 .el o 132 The duplication of system implementation details negatively affects system 133 performance. 134 .RE 135 .sp 136 .LP 137 With Solaris 10, 32-bit system archive libraries are no longer provided. 138 Without these libraries, specifically \fBlibc.a\fR, the creation of static 139 executables is no longer achievable without specialized system knowledge. 140 However, the capability of \fBld\fR to process static linking options, and the 141 processing of archive libraries, remains unchanged. 142 .SH OPTIONS 143 .sp 144 .LP 145 The following options are supported. 146 .sp 147 .ne 2 148 .na 149 \fB\fB-32\fR | \fB-64\fR\fR 150 .ad 151 .sp .6 152 .RS 4n 153 Creates a 32-bit, or 64-bit object. 154 .sp 155 By default, the class of the object being generated is determined from the 156 first \fBELF\fR object processed from the command line. If no objects are 157 specified, the class is determined by the first object encountered within the 158 first archive processed from the command line. If there are no objects or 159 archives, the link-editor creates a 32-bit object. 160 .sp 161 The \fB-64\fR option is required to create a 64-bit object solely from a 162 mapfile. 163 .sp 164 This \fB-32\fR or \fB-64\fR options can also be used in the rare case of 165 linking entirely from an archive that contains a mixture of 32 and 64-bit 166 objects. If the first object in the archive is not the class of the object that 167 is required to be created, then the \fB-32\fR or \fB-64\fR option can be used 168 to direct the link-editor. See \fIThe 32-bit link-editor and 64-bit 169 link-editor\fR in \fILinker and Libraries Guide\fR. 170 .RE 171 172 .sp 173 .ne 2 174 .na 175 \fB\fB-a\fR\fR 176 .ad 177 .sp .6 178 .RS 4n 179 In static mode only, produces an executable object file. Undefined references 180 are not permitted. This option is the default behavior for static mode. The 181 \fB-a\fR option can not be used with the \fB-r\fR option. See \fBStatic 182 Executables\fR under DESCRIPTION. 183 .RE 184 185 .sp 186 .ne 2 187 .na 188 \fB\fB-b\fR\fR 189 .ad 190 .sp .6 191 .RS 4n 192 In dynamic mode only, provides no special processing for dynamic executable 193 relocations that reference symbols in shared objects. Without the \fB-b\fR 194 option, the link-editor applies techniques within a dynamic executable so that 195 the text segment can remain read-only. One technique is the creation of special 196 position-independent relocations for references to functions that are defined 197 in shared objects. Another technique arranges for data objects that are defined 198 in shared objects to be copied into the memory image of an executable at 199 runtime. 200 .sp 201 The \fB-b\fR option is intended for specialized dynamic objects and is not 202 recommended for general use. Its use suppresses all specialized processing 203 required to ensure an object's shareability, and can even prevent the 204 relocation of 64-bit executables. 205 .RE 206 207 .sp 208 .ne 2 209 .na 210 \fB\fB-B\fR \fBdirect\fR | \fBnodirect\fR\fR 211 .ad 212 .sp .6 213 .RS 4n 214 These options govern direct binding. \fB-B\fR \fBdirect\fR establishes direct 215 binding information by recording the relationship between each symbol reference 216 together with the dependency that provides the definition. In addition, direct 217 binding information is established between each symbol reference and an 218 associated definition within the object being created. The runtime linker uses 219 this information to search directly for a symbol in the associated object 220 rather than to carry out a default symbol search. 221 .sp 222 Direct binding information can only be established to dependencies specified 223 with the link-edit. Thus, you should use the \fB-z\fR \fBdefs\fR option. 224 Objects that wish to interpose on symbols in a direct binding environment 225 should identify themselves as interposers with the \fB-z\fR \fBinterpose\fR 226 option. The use of \fB-B\fR \fBdirect\fR enables \fB-z\fR \fBlazyload\fR for 227 all dependencies. 228 .sp 229 The \fB-B\fR \fBnodirect\fR option prevents any direct binding to the 230 interfaces offered by the object being created. The object being created can 231 continue to directly bind to external interfaces by specifying the \fB-z\fR 232 \fBdirect\fR option. See Appendix D, \fIDirect Bindings,\fR in \fILinker and 233 Libraries Guide\fR. 234 .RE 235 236 .sp 237 .ne 2 238 .na 239 \fB\fB-B\fR \fBdynamic\fR | \fBstatic\fR\fR 240 .ad 241 .sp .6 242 .RS 4n 243 Options governing library inclusion. \fB-B\fR \fBdynamic\fR is valid in dynamic 244 mode only. These options can be specified any number of times on the command 245 line as toggles: if the \fB-B\fR \fBstatic\fR option is given, no shared 246 objects are accepted until \fB-B\fR \fBdynamic\fR is seen. See the \fB-l\fR 247 option. 248 .RE 249 250 .sp 251 .ne 2 252 .na 253 \fB\fB-B\fR \fBeliminate\fR\fR 254 .ad 255 .sp .6 256 .RS 4n 257 Causes any global symbols, not assigned to a version definition, to be 258 eliminated from the symbol table. Version definitions can be supplied by means 259 of a \fBmapfile\fR to indicate the global symbols that should remain visible in 260 the generated object. This option achieves the same symbol elimination as the 261 \fIauto-elimination\fR directive that is available as part of a \fBmapfile\fR 262 version definition. This option can be useful when combining versioned and 263 non-versioned relocatable objects. See also the \fB-B\fR \fBlocal\fR option and 264 the \fB-B\fR \fBreduce\fR option. See \fIDefining Additional Symbols with a 265 mapfile\fR in \fILinker and Libraries Guide\fR. 266 .RE 267 268 .sp 269 .ne 2 270 .na 271 \fB\fB-B\fR \fBgroup\fR\fR 272 .ad 273 .sp .6 274 .RS 4n 275 Establishes a shared object and its dependencies as a group. Objects within the 276 group are bound to other members of the group at runtime. This mode is similar 277 to adding the object to the process by using \fBdlopen\fR(3C) with the 278 \fBRTLD_GROUP\fR mode. An object that has an explicit dependency on a object 279 identified as a group, becomes a member of the group. 280 .sp 281 As the group must be self contained, use of the \fB-B\fR \fBgroup\fR option 282 also asserts the \fB-z\fR \fBdefs\fR option. 283 .RE 284 285 .sp 286 .ne 2 287 .na 288 \fB\fB-B\fR \fBlocal\fR\fR 289 .ad 290 .sp .6 291 .RS 4n 292 Causes any global symbols, not assigned to a version definition, to be reduced 293 to local. Version definitions can be supplied by means of a \fBmapfile\fR to 294 indicate the global symbols that should remain visible in the generated object. 295 This option achieves the same symbol reduction as the \fIauto-reduction\fR 296 directive that is available as part of a \fBmapfile\fR version definition. This 297 option can be useful when combining versioned and non-versioned relocatable 298 objects. See also the \fB-B\fR \fBeliminate\fR option and the \fB-B\fR 299 \fBreduce\fR option. See \fIDefining Additional Symbols with a mapfile\fR in 300 \fILinker and Libraries Guide\fR. 301 .RE 302 303 .sp 304 .ne 2 305 .na 306 \fB\fB-B\fR \fBreduce\fR\fR 307 .ad 308 .sp .6 309 .RS 4n 310 When generating a relocatable object, causes the reduction of symbolic 311 information defined by any version definitions. Version definitions can be 312 supplied by means of a \fBmapfile\fR to indicate the global symbols that should 313 remain visible in the generated object. By default, when a relocatable object 314 is generated, version definitions are only recorded in the output image. The 315 actual reduction of symbolic information is carried out when the object is used 316 in the construction of a dynamic executable or shared object. The \fB-B\fR 317 \fBreduce\fR option is applied automatically when a dynamic executable or 318 shared object is created. 319 .RE 320 321 .sp 322 .ne 2 323 .na 324 \fB\fB-B\fR \fBsymbolic\fR\fR 325 .ad 326 .sp .6 327 .RS 4n 328 In dynamic mode only. When building a shared object, binds references to global 329 symbols to their definitions, if available, within the object. Normally, 330 references to global symbols within shared objects are not bound until runtime, 331 even if definitions are available. This model allows definitions of the same 332 symbol in an executable or other shared object to override the object's own 333 definition. \fBld\fR issues warnings for undefined symbols unless \fB-z\fR 334 \fBdefs\fR overrides. 335 .sp 336 The \fB-B\fR \fBsymbolic\fR option is intended for specialized dynamic objects 337 and is not recommended for general use. To reduce the runtime relocation 338 processing that is required an object, the creation of a version definition is 339 recommended. 340 .RE 341 342 .sp 343 .ne 2 344 .na 345 \fB\fB-c\fR \fIname\fR\fR 346 .ad 347 .sp .6 348 .RS 4n 349 Records the configuration file \fIname\fR for use at runtime. Configuration 350 files can be employed to alter default search paths, provide a directory cache, 351 together with providing alternative object dependencies. See \fBcrle\fR(1). 352 .RE 353 354 .sp 355 .ne 2 356 .na 357 \fB\fB-C\fR\fR 358 .ad 359 .sp .6 360 .RS 4n 361 Demangles C++ symbol names displayed in diagnostic messages. 362 .RE 363 364 .sp 365 .ne 2 366 .na 367 \fB\fB-d\fR \fBy\fR | \fBn\fR\fR 368 .ad 369 .sp .6 370 .RS 4n 371 When \fB-d\fR \fBy\fR, the default, is specified, \fBld\fR uses dynamic 372 linking. When \fB-d\fR \fBn\fR is specified, \fBld\fR uses static linking. See 373 \fBStatic Executables\fR under DESCRIPTION, and \fB-B\fR 374 \fBdynamic\fR|\fBstatic\fR. 375 .RE 376 377 .sp 378 .ne 2 379 .na 380 \fB\fB-D\fR \fItoken\fR,...\fR 381 .ad 382 .sp .6 383 .RS 4n 384 Prints debugging information as specified by each \fItoken\fR, to the standard 385 error. The special token \fBhelp\fR indicates the full list of tokens 386 available. See \fIDebugging Aids\fR in \fILinker and Libraries Guide\fR. 387 .RE 388 389 .sp 390 .ne 2 391 .na 392 \fB\fB-e\fR \fIepsym\fR\fR 393 .ad 394 .br 395 .na 396 \fB\fB--entry\fR \fIepsym\fR\fR 397 .ad 398 .sp .6 399 .RS 4n 400 Sets the entry point address for the output file to be the symbol \fIepsym\fR. 401 .RE 402 403 .sp 404 .ne 2 405 .na 406 \fB\fB-f\fR \fIname\fR\fR 407 .ad 408 .br 409 .na 410 \fB\fB--auxiliary\fR \fIname\fR\fR 411 .ad 412 .sp .6 413 .RS 4n 414 Useful only when building a shared object. Specifies that the symbol table of 415 the shared object is used as an auxiliary filter on the symbol table of the 416 shared object specified by \fIname\fR. Multiple instances of this option are 417 allowed. This option can not be combined with the \fB-F\fR option. See 418 \fIGenerating Auxiliary Filters\fR in \fILinker and Libraries Guide\fR. 419 .RE 420 421 .sp 422 .ne 2 423 .na 424 \fB\fB-F\fR \fIname\fR\fR 425 .ad 426 .br 427 .na 428 \fB\fB--filter\fR \fIname\fR\fR 429 .ad 430 .sp .6 431 .RS 4n 432 Useful only when building a shared object. Specifies that the symbol table of 433 the shared object is used as a filter on the symbol table of the shared object 434 specified by \fIname\fR. Multiple instances of this option are allowed. This 435 option can not be combined with the \fB-f\fR option. See \fIGenerating Standard 436 Filters\fR in \fILinker and Libraries Guide\fR. 437 .RE 438 439 .sp 440 .ne 2 441 .na 442 \fB\fB-G\fR\fR 443 .ad 444 .br 445 .na 446 \fB\fB-shared\fR\fR 447 .ad 448 .sp .6 449 .RS 4n 450 In dynamic mode only, produces a shared object. Undefined symbols are allowed. 451 See Chapter 4, \fIShared Objects,\fR in \fILinker and Libraries Guide\fR. 452 .RE 453 454 .sp 455 .ne 2 456 .na 457 \fB\fB-h\fR \fIname\fR\fR 458 .ad 459 .br 460 .na 461 \fB\fB--soname\fR \fIname\fR\fR 462 .ad 463 .sp .6 464 .RS 4n 465 In dynamic mode only, when building a shared object, records \fIname\fR in the 466 object's dynamic section. \fIname\fR is recorded in any dynamic objects that 467 are linked with this object rather than the object's file system name. 468 Accordingly, \fIname\fR is used by the runtime linker as the name of the shared 469 object to search for at runtime. See \fIRecording a Shared Object Name\fR in 470 \fILinker and Libraries Guide\fR. 471 .RE 472 473 .sp 474 .ne 2 475 .na 476 \fB\fB-i\fR\fR 477 .ad 478 .sp .6 479 .RS 4n 480 Ignores \fBLD_LIBRARY_PATH\fR. This option is useful when an 481 \fBLD_LIBRARY_PATH\fR setting is in effect to influence the runtime library 482 search, which would interfere with the link-editing being performed. 483 .RE 484 485 .sp 486 .ne 2 487 .na 488 \fB\fB-I\fR \fIname\fR\fR 489 .ad 490 .br 491 .na 492 \fB\fB--dynamic-linker\fR \fIname\fR\fR 493 .ad 494 .sp .6 495 .RS 4n 496 When building an executable, uses \fIname\fR as the path name of the 497 interpreter to be written into the program header. The default in static mode 498 is no interpreter. In dynamic mode, the default is the name of the runtime 499 linker, \fBld.so.1\fR(1). Either case can be overridden by \fB-I\fR \fIname\fR. 500 \fBexec\fR(2) loads this interpreter when the \fBa.out\fR is loaded, and passes 501 control to the interpreter rather than to the \fBa.out\fR directly. 502 .RE 503 504 .sp 505 .ne 2 506 .na 507 \fB\fB-l\fR \fIx\fR\fR 508 .ad 509 .br 510 .na 511 \fB\fB--library\fR \fIx\fR\fR 512 .ad 513 .sp .6 514 .RS 4n 515 Searches a library \fBlib\fR\fIx\fR\fB\&.so\fR or \fBlib\fR\fIx\fR\fB\&.a\fR, 516 the conventional names for shared object and archive libraries, respectively. 517 In dynamic mode, unless the \fB-B\fR \fBstatic\fR option is in effect, \fBld\fR 518 searches each directory specified in the library search path for a 519 \fBlib\fR\fIx\fR\fB\&.so\fR or \fBlib\fR\fIx\fR\fB\&.a\fR file. The directory 520 search stops at the first directory containing either. \fBld\fR chooses the 521 file ending in \fB\&.so\fR if \fB-l\fR\fIx\fR expands to two files with names 522 of the form \fBlib\fR\fIx\fR\fB\&.so\fR and \fBlib\fR\fIx\fR\fB\&.a\fR. If no 523 \fBlib\fR\fIx\fR\fB\&.so\fR is found, then \fBld\fR accepts 524 \fBlib\fR\fIx\fR\fB\&.a\fR. In static mode, or when the \fB-B\fR \fBstatic\fR 525 option is in effect, \fBld\fR selects only the file ending in \fB\&.a\fR. 526 \fBld\fR searches a library when the library is encountered, so the placement 527 of \fB-l\fR is significant. See \fILinking With Additional Libraries\fR in 528 \fILinker and Libraries Guide\fR. 529 .RE 530 531 .sp 532 .ne 2 533 .na 534 \fB\fB-L\fR \fIpath\fR\fR 535 .ad 536 .br 537 .na 538 \fB\fB--library-path\fR \fIpath\fR\fR 539 .ad 540 .sp .6 541 .RS 4n 542 Adds \fIpath\fR to the library search directories. \fBld\fR searches for 543 libraries first in any directories specified by the \fB-L\fR options and then 544 in the standard directories. This option is useful only if the option precedes 545 the \fB-l\fR options to which the \fB-L\fR option applies. See \fIDirectories 546 Searched by the Link-Editor\fR in \fILinker and Libraries Guide\fR. 547 .sp 548 The environment variable \fBLD_LIBRARY_PATH\fR can be used to supplement the 549 library search path, however the \fB-L\fR option is recommended, as the 550 environment variable is also interpreted by the runtime environment. See 551 \fBLD_LIBRARY_PATH\fR under ENVIRONMENT VARIABLES. 552 .RE 553 554 .sp 555 .ne 2 556 .na 557 \fB\fB-m\fR\fR 558 .ad 559 .sp .6 560 .RS 4n 561 Produces a memory map or listing of the input/output sections, together with 562 any non-fatal multiply-defined symbols, on the standard output. 563 .RE 564 565 .sp 566 .ne 2 567 .na 568 \fB\fB-M\fR \fImapfile\fR\fR 569 .ad 570 .sp .6 571 .RS 4n 572 Reads \fImapfile\fR as a text file of directives to \fBld\fR. This option can 573 be specified multiple times. If \fImapfile\fR is a directory, then all regular 574 files, as defined by \fBstat\fR(2), within the directory are processed. See 575 Chapter 9, \fIMapfile Option,\fR in \fILinker and Libraries Guide\fR. Example 576 mapfiles are provided in \fB/usr/lib/ld\fR. See FILES. 577 .RE 578 579 .sp 580 .ne 2 581 .na 582 \fB\fB-N\fR \fIstring\fR\fR 583 .ad 584 .sp .6 585 .RS 4n 586 This option causes a \fBDT_NEEDED\fR entry to be added to the \fB\&.dynamic\fR 587 section of the object being built. The value of the \fBDT_NEEDED\fR string is 588 the \fIstring\fR that is specified on the command line. This option is position 589 dependent, and the \fBDT_NEEDED\fR \fB\&.dynamic\fR entry is relative to the 590 other dynamic dependencies discovered on the link-edit line. This option is 591 useful for specifying dependencies within device driver relocatable objects 592 when combined with the \fB-dy\fR and \fB-r\fR options. 593 .RE 594 595 .sp 596 .ne 2 597 .na 598 \fB\fB-o\fR \fIoutfile\fR\fR 599 .ad 600 .br 601 .na 602 \fB\fB--output\fR \fIoutfile\fR\fR 603 .ad 604 .sp .6 605 .RS 4n 606 Produces an output object file that is named \fIoutfile\fR. The name of the 607 default object file is \fBa.out\fR. 608 .RE 609 610 .sp 611 .ne 2 612 .na 613 \fB\fB-p\fR \fIauditlib\fR\fR 614 .ad 615 .sp .6 616 .RS 4n 617 Identifies an audit library, \fIauditlib\fR. This audit library is used to 618 audit the object being created at runtime. A shared object identified as 619 requiring auditing with the \fB-p\fR option, has this requirement inherited by 620 any object that specifies the shared object as a dependency. See the \fB-P\fR 621 option. See \fIRuntime Linker Auditing Interface\fR in \fILinker and Libraries 622 Guide\fR. 623 .RE 624 625 .sp 626 .ne 2 627 .na 628 \fB\fB-P\fR \fIauditlib\fR\fR 629 .ad 630 .sp .6 631 .RS 4n 632 Identifies an audit library, \fIauditlib\fR. This audit library is used to 633 audit the dependencies of the object being created at runtime. Dependency 634 auditing can also be inherited from dependencies that are identified as 635 requiring auditing. See the \fB-p\fR option, and the \fB-z\fR \fBglobalaudit\fR 636 option. See \fIRuntime Linker Auditing Interface\fR in \fILinker and Libraries 637 Guide\fR. 638 .RE 639 640 .sp 641 .ne 2 642 .na 643 \fB\fB-Q\fR \fBy\fR | \fBn\fR\fR 644 .ad 645 .sp .6 646 .RS 4n 647 Under \fB-Q\fR \fBy\fR, an \fBident\fR string is added to the \fB\&.comment\fR 648 section of the output file. This string identifies the version of the \fBld\fR 649 used to create the file. This results in multiple \fBld\fR \fBidents\fR when 650 there have been multiple linking steps, such as when using \fBld\fR \fB-r\fR. 651 This identification is identical with the default action of the \fBcc\fR 652 command. \fB-Q\fR \fBn\fR suppresses version identification. \fB\&.comment\fR 653 sections can be manipulated by the \fBmcs\fR(1) utility. 654 .RE 655 656 .sp 657 .ne 2 658 .na 659 \fB\fB-r\fR\fR 660 .ad 661 .br 662 .na 663 \fB\fB--relocatable\fR\fR 664 .ad 665 .sp .6 666 .RS 4n 667 Combines relocatable object files to produce one relocatable object file. 668 \fBld\fR does not complain about unresolved references. This option cannot be 669 used with the \fB-a\fR option. 670 .RE 671 672 .sp 673 .ne 2 674 .na 675 \fB\fB-R\fR \fIpath\fR\fR 676 .ad 677 .br 678 .na 679 \fB\fB-rpath\fR \fIpath\fR\fR 680 .ad 681 .sp .6 682 .RS 4n 683 A colon-separated list of directories used to specify library search 684 directories to the runtime linker. If present and not NULL, the path is 685 recorded in the output object file and passed to the runtime linker. Multiple 686 instances of this option are concatenated together with each \fIpath\fR 687 separated by a colon. See \fIDirectories Searched by the Runtime Linker\fR in 688 \fILinker and Libraries Guide\fR. 689 .sp 690 The use of a runpath within an associated object is preferable to setting 691 global search paths such as through the \fBLD_LIBRARY_PATH\fR environment 692 variable. Only the runpaths that are necessary to find the objects dependencies 693 should be recorded. \fBldd\fR(1) can also be used to discover unused runpaths 694 in dynamic objects, when used with the \fB-U\fR option. 695 .sp 696 Various tokens can also be supplied with a runpath that provide a flexible 697 means of identifying system capabilities or an objects location. See Appendix 698 C, \fIEstablishing Dependencies with Dynamic String Tokens,\fR in \fILinker and 699 Libraries Guide\fR. The \fB$ORIGIN\fR token is especially useful in allowing 700 dynamic objects to be relocated to different locations in the file system. 701 .RE 702 703 .sp 704 .ne 2 705 .na 706 \fB\fB-s\fR\fR 707 .ad 708 .br 709 .na 710 \fB\fB--strip-all\fR\fR 711 .ad 712 .sp .6 713 .RS 4n 714 Strips symbolic information from the output file. Any debugging information, 715 that is, \fB\&.line\fR, \fB\&.debug*\fR, and \fB\&.stab*\fR sections, and their 716 associated relocation entries are removed. Except for relocatable files, a 717 symbol table \fBSHT_SYMTAB\fR and its associated string table section are not 718 created in the output object file. The elimination of a \fBSHT_SYMTAB\fR symbol 719 table can reduce the \fB\&.stab*\fR debugging information that is generated 720 using the compiler drivers \fB-g\fR option. See the \fB-z\fR \fBredlocsym\fR 721 and \fB-z\fR \fBnoldynsym\fR options. 722 .RE 723 724 .sp 725 .ne 2 726 .na 727 \fB\fB-S\fR \fIsupportlib\fR\fR 728 .ad 729 .sp .6 730 .RS 4n 731 The shared object \fIsupportlib\fR is loaded with \fBld\fR and given 732 information regarding the linking process. Shared objects that are defined by 733 using the \fB-S\fR option can also be supplied using the \fBSGS_SUPPORT\fR 734 environment variable. See \fILink-Editor Support Interface\fR in \fILinker and 735 Libraries Guide\fR. 736 .RE 737 738 .sp 739 .ne 2 740 .na 741 \fB\fB-t\fR\fR 742 .ad 743 .sp .6 744 .RS 4n 745 Turns off the warning for multiply-defined symbols that have different sizes or 746 different alignments. 747 .RE 748 749 .sp 750 .ne 2 751 .na 752 \fB\fB-u\fR \fIsymname\fR\fR 753 .ad 754 .br 755 .na 756 \fB\fB--undefined\fR \fIsymname\fR\fR 757 .ad 758 .sp .6 759 .RS 4n 760 Enters \fIsymname\fR as an undefined symbol in the symbol table. This option is 761 useful for loading entirely from an archive library. In this instance, an 762 unresolved reference is needed to force the loading of the first routine. The 763 placement of this option on the command line is significant. This option must 764 be placed before the library that defines the symbol. See \fIDefining 765 Additional Symbols with the u option\fR in \fILinker and Libraries Guide\fR. 766 .RE 767 768 .sp 769 .ne 2 770 .na 771 \fB\fB-V\fR\fR 772 .ad 773 .br 774 .na 775 \fB\fB--version\fR\fR 776 .ad 777 .sp .6 778 .RS 4n 779 Outputs a message giving information about the version of \fBld\fR being used. 780 .RE 781 782 .sp 783 .ne 2 784 .na 785 \fB\fB-Y\fR \fBP,\fR\fIdirlist\fR\fR 786 .ad 787 .sp .6 788 .RS 4n 789 Changes the default directories used for finding libraries. \fIdirlist\fR is a 790 colon-separated path list. 791 .RE 792 793 .sp 794 .ne 2 795 .na 796 \fB\fB-z\fR \fBabsexec\fR\fR 797 .ad 798 .sp .6 799 .RS 4n 800 Useful only when building a dynamic executable. Specifies that references to 801 external absolute symbols should be resolved immediately instead of being left 802 for resolution at runtime. In very specialized circumstances, this option 803 removes text relocations that can result in excessive swap space demands by an 804 executable. 805 .RE 806 807 .sp 808 .ne 2 809 .na 810 \fB\fB-z\fR \fBallextract\fR | \fBdefaultextract\fR | \fBweakextract\fR\fR 811 .ad 812 .br 813 .na 814 \fB\fB--whole-archive\fR | \fB--no-whole-archive\fR\fR 815 .ad 816 .sp .6 817 .RS 4n 818 Alters the extraction criteria of objects from any archives that follow. By 819 default, archive members are extracted to satisfy undefined references and to 820 promote tentative definitions with data definitions. Weak symbol references do 821 not trigger extraction. Under the \fB-z\fR \fBallextract\fR or 822 \fB--whole-archive\fR options, all archive members are extracted from the 823 archive. Under \fB-z\fR \fBweakextract\fR, weak references trigger archive 824 extraction. The \fB-z\fR \fBdefaultextract\fR or \fB--no-whole-archive\fR 825 options provide a means of returning to the default following use of the former 826 extract options. See \fIArchive Processing\fR in \fILinker and Libraries 827 Guide\fR. 828 .RE 829 830 .sp 831 .ne 2 832 .na 833 \fB\fB-z\fR \fBaltexec64\fR\fR 834 .ad 835 .sp .6 836 .RS 4n 837 Execute the 64-bit \fBld\fR. The creation of very large 32-bit objects can 838 exhaust the virtual memory that is available to the 32-bit \fBld\fR. The 839 \fB-z\fR \fBaltexec64\fR option can be used to force the use of the associated 840 64-bit \fBld\fR. The 64-bit \fBld\fR provides a larger virtual address space 841 for building 32-bit objects. See \fIThe 32-bit link-editor and 64-bit 842 link-editor\fR in \fILinker and Libraries Guide\fR. 843 .RE 844 845 .sp 846 .ne 2 847 .na 848 \fB-z\fR \fBaslr[=\fIstate\fR]\fR 849 .ad 850 .sp .6 851 .RS 4n 852 Specify whether the executable's address space should be randomized on 853 execution. If \fIstate\fR is "enabled" randomization will always occur when 854 this executable is run (regardless of inherited settings). If \fIstate\fR is 855 "disabled" randomization will never occur when this executable is run. If 856 \fIstate\fR is omitted, ASLR is enabled. 857 858 An executable that should simple use the settings inherited from its 859 environment should not use this flag at all. 860 .RE 861 862 .sp 863 .ne 2 864 .na 865 \fB\fB-z\fR \fBcombreloc\fR | \fBnocombreloc\fR\fR 866 .ad 867 .sp .6 868 .RS 4n 869 By default, \fBld\fR combines multiple relocation sections when building 870 executables or shared objects. This section combination differs from 871 relocatable objects, in which relocation sections are maintained in a 872 one-to-one relationship with the sections to which the relocations must be 873 applied. The \fB-z\fR \fBnocombreloc\fR option disables this merging of 874 relocation sections, and preserves the one-to-one relationship found in the 875 original relocatable objects. 876 .sp 877 \fBld\fR sorts the entries of data relocation sections by their symbol 878 reference. This sorting reduces runtime symbol lookup. When multiple relocation 879 sections are combined, this sorting produces the least possible relocation 880 overhead when objects are loaded into memory, and speeds the runtime loading of 881 dynamic objects. 882 .sp 883 Historically, the individual relocation sections were carried over to any 884 executable or shared object, and the \fB-z\fR \fBcombreloc\fR option was 885 required to enable the relocation section merging previously described. 886 Relocation section merging is now the default. The \fB-z\fR \fBcombreloc\fR 887 option is still accepted for the benefit of old build environments, but the 888 option is unnecessary, and has no effect. 889 .RE 890 891 .sp 892 .ne 2 893 .na 894 \fB\fB-z\fR \fBassert-deflib\fR\fR 895 .ad 896 .br 897 .na 898 \fB\fB-z\fR \fBassert-deflib=\fR\fIlibname\fR\fR 899 .ad 900 .sp .6 901 .RS 4n 902 Enables warnings that check the location of where libraries passed in with 903 \fB-l\fR are found. If the link-editor finds a library on its default search 904 path it will emit a warning. This warning can be made fatal in conjunction with 905 the option \fB-z fatal-warnings\fR. Passing \fIlibname\fR white lists a library 906 from this check. The library must be the full name of the library, e.g. 907 \fIlibc.so\fR. To white list multiple libraries, the \fB-z 908 assert-deflib=\fR\fIlibname\fR option can be repeated multiple times. This 909 option is useful when trying to build self-contained objects where a referenced 910 library might exist in the default system library path and in alternate paths 911 specified by \fB-L\fR, but you only want the alternate paths to be used. 912 .RE 913 914 .sp 915 .ne 2 916 .na 917 \fB\fB-z\fR \fBdefs\fR | \fBnodefs\fR\fR 918 .ad 919 .br 920 .na 921 \fB\fB--no-undefined\fR\fR 922 .ad 923 .sp .6 924 .RS 4n 925 The \fB-z\fR \fBdefs\fR option and the \fB--no-undefined\fR option force a 926 fatal error if any undefined symbols remain at the end of the link. This mode 927 is the default when an executable is built. For historic reasons, this mode is 928 \fBnot\fR the default when building a shared object. Use of the \fB-z\fR 929 \fBdefs\fR option is recommended, as this mode assures the object being built 930 is self-contained. A self-contained object has all symbolic references resolved 931 internally, or to the object's immediate dependencies. 932 .sp 933 The \fB-z\fR \fBnodefs\fR option allows undefined symbols. For historic 934 reasons, this mode is the default when a shared object is built. When used with 935 executables, the behavior of references to such undefined symbols is 936 unspecified. Use of the \fB-z\fR \fBnodefs\fR option is not recommended. 937 .RE 938 939 .sp 940 .ne 2 941 .na 942 \fB\fB-z\fR \fBdirect\fR | \fBnodirect\fR\fR 943 .ad 944 .sp .6 945 .RS 4n 946 Enables or disables direct binding to any dependencies that follow on the 947 command line. These options allow finer control over direct binding than the 948 global counterpart \fB-B\fR \fBdirect\fR. The \fB-z\fR \fBdirect\fR option also 949 differs from the \fB-B\fR \fBdirect\fR option in the following areas. Direct 950 binding information is not established between a symbol reference and an 951 associated definition within the object being created. Lazy loading is not 952 enabled. 953 .RE 954 955 .sp 956 .ne 2 957 .na 958 \fB\fB-z\fR \fBendfiltee\fR\fR 959 .ad 960 .sp .6 961 .RS 4n 962 Marks a filtee so that when processed by a filter, the filtee terminates any 963 further filtee searches by the filter. See \fIReducing Filtee Searches\fR in 964 \fILinker and Libraries Guide\fR. 965 .RE 966 967 .sp 968 .ne 2 969 .na 970 \fB\fB-z\fR \fBfatal-warnings\fR | \fBnofatal-warnings\fR\fR 971 .ad 972 .br 973 .na 974 \fB\fB--fatal-warnings\fR | \fB--no-fatal-warnings\fR 975 .ad 976 .sp .6 977 .RS 4n 978 Controls the behavior of warnings emitted from the link-editor. Setting \fB-z 979 fatal-warnings\fR promotes warnings emitted by the link-editor to fatal errors 980 that will cause the link-editor to fail before linking. \fB-z 981 nofatal-warnings\fR instead demotes these warnings such that they will not cause 982 the link-editor to exit prematurely. 983 .RE 984 985 986 .sp 987 .ne 2 988 .na 989 \fB\fB-z\fR \fBfiniarray=\fR\fIfunction\fR\fR 990 .ad 991 .sp .6 992 .RS 4n 993 Appends an entry to the \fB\&.finiarray\fR section of the object being built. 994 If no \fB\&.finiarray\fR section is present, a section is created. The new 995 entry is initialized to point to \fIfunction\fR. See \fIInitialization and 996 Termination Sections\fR in \fILinker and Libraries Guide\fR. 997 .RE 998 999 .sp 1000 .ne 2 1001 .na 1002 \fB\fB-z\fR \fBglobalaudit\fR\fR 1003 .ad 1004 .sp .6 1005 .RS 4n 1006 This option supplements an audit library definition that has been recorded with 1007 the \fB-P\fR option. This option is only meaningful when building a dynamic 1008 executable. Audit libraries that are defined within an object with the \fB-P\fR 1009 option typically allow for the auditing of the immediate dependencies of the 1010 object. The \fB-z\fR \fBglobalaudit\fR promotes the auditor to a global 1011 auditor, thus allowing the auditing of all dependencies. See \fIInvoking the 1012 Auditing Interface\fR in \fILinker and Libraries Guide\fR. 1013 .sp 1014 An auditor established with the \fB-P\fR option and the \fB-z\fR 1015 \fBglobalaudit\fR option, is equivalent to the auditor being established with 1016 the \fBLD_AUDIT\fR environment variable. See \fBld.so.1\fR(1). 1017 .RE 1018 1019 .sp 1020 .ne 2 1021 .na 1022 \fB\fB-z\fR \fBgroupperm\fR | \fBnogroupperm\fR\fR 1023 .ad 1024 .sp .6 1025 .RS 4n 1026 Assigns, or deassigns each dependency that follows to a unique group. The 1027 assignment of a dependency to a group has the same effect as if the dependency 1028 had been built using the \fB-B\fR \fBgroup\fR option. 1029 .RE 1030 1031 .sp 1032 .ne 2 1033 .na 1034 \fB-z\fR \fBguidance\fR[=\fIid1\fR,\fIid2\fR...] 1035 .ad 1036 .sp .6 1037 .RS 4n 1038 Give messages suggesting link-editor features that could improve the resulting 1039 dynamic object. 1040 .LP 1041 Specific classes of suggestion can be silenced by specifying an optional comma separated 1042 list of guidance identifiers. 1043 .LP 1044 The current classes of suggestion provided are: 1045 1046 .sp 1047 .ne 2 1048 .na 1049 Enable use of direct binding 1050 .ad 1051 .sp .6 1052 .RS 4n 1053 Suggests that \fB-z direct\fR or \fB-B direct\fR be present prior to any 1054 specified dependency. This allows predictable symbol binding at runtime. 1055 1056 Can be disabled with \fB-z guidance=nodirect\fR 1057 .RE 1058 1059 .sp 1060 .ne 2 1061 .na 1062 Enable lazy dependency loading 1063 .ad 1064 .sp .6 1065 .RS 4n 1066 Suggests that \fB-z lazyload\fR be present prior to any specified dependency. 1067 This allows the dynamic object to be loaded more quickly. 1068 1069 Can be disabled with \fB-z guidance=nolazyload\fR. 1070 .RE 1071 1072 .sp 1073 .ne 2 1074 .na 1075 Shared objects should define all their dependencies. 1076 .ad 1077 .sp .6 1078 .RS 4n 1079 Suggests that \fB-z defs\fR be specified on the link-editor command line. 1080 Shared objects that explicitly state all their dependencies behave more 1081 predictably when used. 1082 1083 Can be be disabled with \fB-z guidance=nodefs\fR 1084 .RE 1085 1086 .sp 1087 .ne 2 1088 .na 1089 Version 2 mapfile syntax 1090 .ad 1091 .sp .6 1092 .RS 4n 1093 Suggests that any specified mapfiles use the more readable version 2 syntax. 1094 1095 Can be disabled with \fB-z guidance=nomapfile\fR. 1096 .RE 1097 1098 .sp 1099 .ne 2 1100 .na 1101 Read-only text segment 1102 .ad 1103 .sp .6 1104 .RS 4n 1105 Should any runtime relocations within the text segment exist, suggests that 1106 the object be compiled with position independent code (PIC). Keeping large 1107 allocatable sections read-only allows them to be shared between processes 1108 using a given shared object. 1109 1110 Can be disabled with \fB-z guidance=notext\fR 1111 .RE 1112 1113 .sp 1114 .ne 2 1115 .na 1116 No unused dependencies 1117 .ad 1118 .sp .6 1119 .RS 4n 1120 Suggests that any dependency not referenced by the resulting dynamic object be 1121 removed from the link-editor command line. 1122 1123 Can be disabled with \fB-z guidance=nounused\fR. 1124 .RE 1125 .RE 1126 1127 .sp 1128 .ne 2 1129 .na 1130 \fB\fB-z\fR \fBhelp\fR\fR 1131 .ad 1132 .br 1133 .na 1134 \fB\fB--help\fR\fR 1135 .ad 1136 .sp .6 1137 .RS 4n 1138 Print a summary of the command line options on the standard output and exit. 1139 .RE 1140 1141 .sp 1142 .ne 2 1143 .na 1144 \fB\fB-z\fR \fBignore\fR | \fBrecord\fR\fR 1145 .ad 1146 .sp .6 1147 .RS 4n 1148 Ignores, or records, dynamic dependencies that are not referenced as part of 1149 the link-edit. Ignores, or records, unreferenced \fBELF\fR sections from the 1150 relocatable objects that are read as part of the link-edit. By default, 1151 \fB-z\fR \fBrecord\fR is in effect. 1152 .sp 1153 If an \fBELF\fR section is ignored, the section is eliminated from the output 1154 file being generated. A section is ignored when three conditions are true. The 1155 eliminated section must contribute to an allocatable segment. The eliminated 1156 section must provide no global symbols. No other section from any object that 1157 contributes to the link-edit, must reference an eliminated section. 1158 .RE 1159 1160 .sp 1161 .ne 2 1162 .na 1163 \fB\fB-z\fR \fBinitarray=\fR\fIfunction\fR\fR 1164 .ad 1165 .sp .6 1166 .RS 4n 1167 Appends an entry to the \fB\&.initarray\fR section of the object being built. 1168 If no \fB\&.initarray\fR section is present, a section is created. The new 1169 entry is initialized to point to \fIfunction\fR. See \fIInitialization and 1170 Termination Sections\fR in \fILinker and Libraries Guide\fR. 1171 .RE 1172 1173 .sp 1174 .ne 2 1175 .na 1176 \fB\fB-z\fR \fBinitfirst\fR\fR 1177 .ad 1178 .sp .6 1179 .RS 4n 1180 Marks the object so that its runtime initialization occurs before the runtime 1181 initialization of any other objects brought into the process at the same time. 1182 In addition, the object runtime finalization occurs after the runtime 1183 finalization of any other objects removed from the process at the same time. 1184 This option is only meaningful when building a shared object. 1185 .RE 1186 1187 .sp 1188 .ne 2 1189 .na 1190 \fB\fB-z\fR \fBinterpose\fR\fR 1191 .ad 1192 .sp .6 1193 .RS 4n 1194 Marks the object as an interposer. At runtime, an object is identified as an 1195 explicit interposer if the object has been tagged using the \fB-z interpose\fR 1196 option. An explicit interposer is also established when an object is loaded 1197 using the \fBLD_PRELOAD\fR environment variable. Implicit interposition can 1198 occur because of the load order of objects, however, this implicit 1199 interposition is unknown to the runtime linker. Explicit interposition can 1200 ensure that interposition takes place regardless of the order in which objects 1201 are loaded. Explicit interposition also ensures that the runtime linker 1202 searches for symbols in any explicit interposers when direct bindings are in 1203 effect. 1204 .RE 1205 1206 .sp 1207 .ne 2 1208 .na 1209 \fB\fB-z\fR \fBlazyload\fR | \fBnolazyload\fR\fR 1210 .ad 1211 .sp .6 1212 .RS 4n 1213 Enables or disables the marking of dynamic dependencies to be lazily loaded. 1214 Dynamic dependencies which are marked \fBlazyload\fR are not loaded at initial 1215 process start-up. These dependencies are delayed until the first binding to the 1216 object is made. \fBNote:\fR Lazy loading requires the correct declaration of 1217 dependencies, together with associated runpaths for each dynamic object used 1218 within a process. See \fILazy Loading of Dynamic Dependencies\fR in \fILinker 1219 and Libraries Guide\fR. 1220 .RE 1221 1222 .sp 1223 .ne 2 1224 .na 1225 \fB\fB-z\fR \fBld32\fR=\fIarg1\fR,\fIarg2\fR,...\fR 1226 .ad 1227 .br 1228 .na 1229 \fB\fB-z\fR \fBld64\fR=\fIarg1\fR,\fIarg2\fR,...\fR 1230 .ad 1231 .sp .6 1232 .RS 4n 1233 The class of the link-editor is affected by the class of the output file being 1234 created and by the capabilities of the underlying operating system. The 1235 \fB-z\fR \fBld\fR[\fB32\fR|\fB64\fR] options provide a means of defining any 1236 link-editor argument. The defined argument is only interpreted, respectively, 1237 by the 32-bit class or 64-bit class of the link-editor. 1238 .sp 1239 For example, support libraries are class specific, so the correct class of 1240 support library can be ensured using: 1241 .sp 1242 .in +2 1243 .nf 1244 \fBld ... -z ld32=-Saudit32.so.1 -z ld64=-Saudit64.so.1 ...\fR 1245 .fi 1246 .in -2 1247 .sp 1248 1249 The class of link-editor that is invoked is determined from the \fBELF\fR class 1250 of the first relocatable file that is seen on the command line. This 1251 determination is carried out \fBprior\fR to any \fB-z\fR 1252 \fBld\fR[\fB32\fR|\fB64\fR] processing. 1253 .RE 1254 1255 .sp 1256 .ne 2 1257 .na 1258 \fB\fB-z\fR \fBloadfltr\fR\fR 1259 .ad 1260 .sp .6 1261 .RS 4n 1262 Marks a filter to indicate that filtees must be processed immediately at 1263 runtime. Normally, filter processing is delayed until a symbol reference is 1264 bound to the filter. The runtime processing of an object that contains this 1265 flag mimics that which occurs if the \fBLD_LOADFLTR\fR environment variable is 1266 in effect. See the \fBld.so.1\fR(1). 1267 .RE 1268 1269 .sp 1270 .ne 2 1271 .na 1272 \fB\fB-z\fR \fBmuldefs\fR\fR 1273 .ad 1274 .br 1275 .na 1276 \fB\fB--allow-multiple-definition\fR\fR 1277 .ad 1278 .sp .6 1279 .RS 4n 1280 Allows multiple symbol definitions. By default, multiple symbol definitions 1281 that occur between relocatable objects result in a fatal error condition. This 1282 option, suppresses the error condition, allowing the first symbol definition to 1283 be taken. 1284 .RE 1285 1286 .sp 1287 .ne 2 1288 .na 1289 \fB\fB-z\fR \fBnocompstrtab\fR\fR 1290 .ad 1291 .sp .6 1292 .RS 4n 1293 Disables the compression of \fBELF\fR string tables. By default, string 1294 compression is applied to \fBSHT_STRTAB\fR sections, and to \fBSHT_PROGBITS\fR 1295 sections that have their \fBSHF_MERGE\fR and \fBSHF_STRINGS\fR section flags 1296 set. 1297 .RE 1298 1299 .sp 1300 .ne 2 1301 .na 1302 \fB\fB-z\fR \fBnodefaultlib\fR\fR 1303 .ad 1304 .sp .6 1305 .RS 4n 1306 Marks the object so that the runtime default library search path, used after 1307 any \fBLD_LIBRARY_PATH\fR or runpaths, is ignored. This option implies that all 1308 dependencies of the object can be satisfied from its runpath. 1309 .RE 1310 1311 .sp 1312 .ne 2 1313 .na 1314 \fB\fB-z\fR \fBnodelete\fR\fR 1315 .ad 1316 .sp .6 1317 .RS 4n 1318 Marks the object as non-deletable at runtime. This mode is similar to adding 1319 the object to the process by using \fBdlopen\fR(3C) with the 1320 \fBRTLD_NODELETE\fR mode. 1321 .RE 1322 1323 .sp 1324 .ne 2 1325 .na 1326 \fB\fB-z\fR \fBnodlopen\fR\fR 1327 .ad 1328 .sp .6 1329 .RS 4n 1330 Marks the object as not available to \fBdlopen\fR(3C), either as the object 1331 specified by the \fBdlopen()\fR, or as any form of dependency required by the 1332 object specified by the \fBdlopen()\fR. This option is only meaningful when 1333 building a shared object. 1334 .RE 1335 1336 .sp 1337 .ne 2 1338 .na 1339 \fB\fB-z\fR \fBnodump\fR\fR 1340 .ad 1341 .sp .6 1342 .RS 4n 1343 Marks the object as not available to \fBdldump\fR(3C). 1344 .RE 1345 1346 .sp 1347 .ne 2 1348 .na 1349 \fB\fB-z\fR \fBnoldynsym\fR\fR 1350 .ad 1351 .sp .6 1352 .RS 4n 1353 Prevents the inclusion of a \fB\&.SUNW_ldynsym\fR section in dynamic 1354 executables or sharable libraries. The \fB\&.SUNW_ldynsym\fR section augments 1355 the \fB\&.dynsym\fR section by providing symbols for local functions. Local 1356 function symbols allow debuggers to display local function names in stack 1357 traces from stripped programs. Similarly, \fBdladdr\fR(3C) is able to supply 1358 more accurate results. 1359 .sp 1360 The \fB-z\fR \fBnoldynsym\fR option also prevents the inclusion of the two 1361 symbol sort sections that are related to the \fB\&.SUNW_ldynsym\fR section. The 1362 \fB\&.SUNW_dynsymsort\fR section provides sorted access to regular function and 1363 variable symbols. The \fB\&.SUNW_dyntlssort\fR section provides sorted access 1364 to thread local storage (\fBTLS\fR) variable symbols. 1365 .sp 1366 The \fB\&.SUNW_ldynsym\fR, \fB\&.SUNW_dynsymsort\fR, and 1367 \fB\&.SUNW_dyntlssort\fR sections, which becomes part of the allocable text 1368 segment of the resulting file, cannot be removed by \fBstrip\fR(1). Therefore, 1369 the \fB-z\fR \fBnoldynsym\fR option is the only way to prevent their inclusion. 1370 See the \fB-s\fR and \fB-z\fR \fBredlocsym\fR options. 1371 .RE 1372 1373 .sp 1374 .ne 2 1375 .na 1376 \fB\fB-z\fR \fBnopartial\fR\fR 1377 .ad 1378 .sp .6 1379 .RS 4n 1380 Partially initialized symbols, that are defined within relocatable object 1381 files, are expanded in the output file being generated. 1382 .RE 1383 1384 .sp 1385 .ne 2 1386 .na 1387 \fB\fB-z\fR \fBnoversion\fR\fR 1388 .ad 1389 .sp .6 1390 .RS 4n 1391 Does not record any versioning sections. Any version sections or associated 1392 \fB\&.dynamic\fR section entries are not generated in the output image. 1393 .RE 1394 1395 .sp 1396 .ne 2 1397 .na 1398 \fB\fB-z\fR \fBnow\fR\fR 1399 .ad 1400 .sp .6 1401 .RS 4n 1402 Marks the object as requiring non-lazy runtime binding. This mode is similar to 1403 adding the object to the process by using \fBdlopen\fR(3C) with the 1404 \fBRTLD_NOW\fR mode. This mode is also similar to having the \fBLD_BIND_NOW\fR 1405 environment variable in effect. See \fBld.so.1\fR(1). 1406 .RE 1407 1408 .sp 1409 .ne 2 1410 .na 1411 \fB\fB-z\fR \fBorigin\fR\fR 1412 .ad 1413 .sp .6 1414 .RS 4n 1415 Marks the object as requiring immediate \fB$ORIGIN\fR processing at runtime. 1416 This option is only maintained for historic compatibility, as the runtime 1417 analysis of objects to provide for \fB$ORIGIN\fR processing is now default. 1418 .RE 1419 1420 .sp 1421 .ne 2 1422 .na 1423 \fB\fB-z\fR \fBpreinitarray=\fR\fIfunction\fR\fR 1424 .ad 1425 .sp .6 1426 .RS 4n 1427 Appends an entry to the \fB\&.preinitarray\fR section of the object being 1428 built. If no \fB\&.preinitarray\fR section is present, a section is created. 1429 The new entry is initialized to point to \fIfunction\fR. See \fIInitialization 1430 and Termination Sections\fR in \fILinker and Libraries Guide\fR. 1431 .RE 1432 1433 .sp 1434 .ne 2 1435 .na 1436 \fB\fB-z\fR \fBredlocsym\fR\fR 1437 .ad 1438 .sp .6 1439 .RS 4n 1440 Eliminates all local symbols except for the \fISECT\fR symbols from the symbol 1441 table \fBSHT_SYMTAB\fR. All relocations that refer to local symbols are updated 1442 to refer to the corresponding \fISECT\fR symbol. This option allows specialized 1443 objects to greatly reduce their symbol table sizes. Eliminated local symbols 1444 can reduce the \fB\&.stab*\fR debugging information that is generated using the 1445 compiler drivers \fB-g\fR option. See the \fB-s\fR and \fB-z\fR \fBnoldynsym\fR 1446 options. 1447 .RE 1448 1449 .sp 1450 .ne 2 1451 .na 1452 \fB\fB-z\fR \fBrelaxreloc\fR\fR 1453 .ad 1454 .sp .6 1455 .RS 4n 1456 \fBld\fR normally issues a fatal error upon encountering a relocation using a 1457 symbol that references an eliminated COMDAT section. If \fB-z\fR 1458 \fBrelaxreloc\fR is enabled, \fBld\fR instead redirects such relocations to the 1459 equivalent symbol in the COMDAT section that was kept. \fB-z\fR 1460 \fBrelaxreloc\fR is a specialized option, mainly of interest to compiler 1461 authors, and is not intended for general use. 1462 .RE 1463 1464 .sp 1465 .ne 2 1466 .na 1467 \fB\fB-z\fR \fBrescan-now\fR\fR 1468 .ad 1469 .br 1470 .na 1471 \fB\fB-z\fR \fBrescan\fR\fR 1472 .ad 1473 .sp .6 1474 .RS 4n 1475 These options rescan the archive files that are provided to the link-edit. By 1476 default, archives are processed once as the archives appear on the command 1477 line. Archives are traditionally specified at the end of the command line so 1478 that their symbol definitions resolve any preceding references. However, 1479 specifying archives multiple times to satisfy their own interdependencies can 1480 be necessary. 1481 .sp 1482 \fB-z\fR \fBrescan-now\fR is a positional option, and is processed by the 1483 link-editor immediately when encountered on the command line. All archives seen 1484 on the command line up to that point are immediately reprocessed in an attempt 1485 to locate additional archive members that resolve symbol references. This 1486 archive rescanning is repeated until a pass over the archives occurs in which 1487 no new members are extracted. 1488 .sp 1489 \fB-z\fR \fBrescan\fR is a position independent option. The link-editor defers 1490 the rescan operation until after it has processed the entire command line, and 1491 then initiates a final rescan operation over all archives seen on the command 1492 line. The \fB-z\fR \fBrescan\fR operation can interact incorrectly 1493 with objects that contain initialization (.init) or finalization (.fini) 1494 sections, preventing the code in those sections from running. For this reason, 1495 \fB-z\fR \fBrescan\fR is deprecated, and use of \fB-z\fR \fBrescan-now\fR is 1496 advised. 1497 .RE 1498 1499 .sp 1500 .ne 2 1501 .na 1502 \fB\fB-z\fR \fBrescan-start\fR ... \fB-z\fR \fBrescan-end\fR\fR 1503 .ad 1504 .br 1505 .na 1506 \fB\fB--start-group\fR ... \fB--end-group\fR\fR 1507 .ad 1508 .br 1509 .na 1510 \fB\fB-(\fR ... \fB-)\fR\fR 1511 .ad 1512 .sp .6 1513 .RS 4n 1514 Defines an archive rescan group. This is a positional construct, and is 1515 processed by the link-editor immediately upon encountering the closing 1516 delimiter option. Archives found within the group delimiter options are 1517 reprocessed as a group in an attempt to locate additional archive members that 1518 resolve symbol references. This archive rescanning is repeated until a pass 1519 over the archives On the occurs in which no new members are extracted. 1520 Archive rescan groups cannot be nested. 1521 .RE 1522 1523 .sp 1524 .ne 2 1525 .na 1526 \fB\fB-z\fR \fBtarget=sparc|x86\fR \fI\fR\fR 1527 .ad 1528 .sp .6 1529 .RS 4n 1530 Specifies the machine type for the output object. Supported targets are Sparc 1531 and x86. The 32-bit machine type for the specified target is used unless the 1532 \fB-64\fR option is also present, in which case the corresponding 64-bit 1533 machine type is used. By default, the machine type of the object being 1534 generated is determined from the first \fBELF\fR object processed from the 1535 command line. If no objects are specified, the machine type is determined by 1536 the first object encountered within the first archive processed from the 1537 command line. If there are no objects or archives, the link-editor assumes the 1538 native machine. This option is useful when creating an object directly with 1539 \fBld\fR whose input is solely from a \fBmapfile\fR. See the \fB-M\fR option. 1540 It can also be useful in the rare case of linking entirely from an archive that 1541 contains objects of different machine types for which the first object is not 1542 of the desired machine type. See \fIThe 32-bit link-editor and 64-bit 1543 link-editor\fR in \fILinker and Libraries Guide\fR. 1544 .RE 1545 1546 .sp 1547 .ne 2 1548 .na 1549 \fB\fB-z\fR \fBtext\fR\fR 1550 .ad 1551 .sp .6 1552 .RS 4n 1553 In dynamic mode only, forces a fatal error if any relocations against 1554 non-writable, allocatable sections remain. For historic reasons, this mode is 1555 not the default when building an executable or shared object. However, its use 1556 is recommended to ensure that the text segment of the dynamic object being 1557 built is shareable between multiple running processes. A shared text segment 1558 incurs the least relocation overhead when loaded into memory. See 1559 \fIPosition-Independent Code\fR in \fILinker and Libraries Guide\fR. 1560 .RE 1561 1562 .sp 1563 .ne 2 1564 .na 1565 \fB\fB-z\fR \fBtextoff\fR\fR 1566 .ad 1567 .sp .6 1568 .RS 4n 1569 In dynamic mode only, allows relocations against all allocatable sections, 1570 including non-writable ones. This mode is the default when building a shared 1571 object. 1572 .RE 1573 1574 .sp 1575 .ne 2 1576 .na 1577 \fB\fB-z\fR \fBtextwarn\fR\fR 1578 .ad 1579 .sp .6 1580 .RS 4n 1581 In dynamic mode only, lists a warning if any relocations against non-writable, 1582 allocatable sections remain. This mode is the default when building an 1583 executable. 1584 .RE 1585 1586 .sp 1587 .ne 2 1588 .na 1589 \fB\fB-z\fR \fBverbose\fR\fR 1590 .ad 1591 .sp .6 1592 .RS 4n 1593 This option provides additional warning diagnostics during a link-edit. 1594 Presently, this option conveys suspicious use of displacement relocations. This 1595 option also conveys the restricted use of static \fBTLS\fR relocations when 1596 building shared objects. In future, this option might be enhanced to provide 1597 additional diagnostics that are deemed too noisy to be generated by default. 1598 .RE 1599 1600 .sp 1601 .ne 2 1602 .na 1603 \fB\fB-z\fR\fBwrap=\fR\fIsymbol\fR\fR 1604 .ad 1605 .br 1606 .na 1607 \fB\fB-wrap=\fR \fIsymbol\fR\fR 1608 .ad 1609 .br 1610 .na 1611 \fB\fB--wrap=\fR \fIsymbol\fR\fR 1612 .ad 1613 .sp .6 1614 .RS 4n 1615 Rename undefined references to \fIsymbol\fR in order to allow wrapper code to 1616 be linked into the output object without having to modify source code. When 1617 \fB-z wrap\fR is specified, all undefined references to \fIsymbol\fR are 1618 modified to reference \fB__wrap_\fR\fIsymbol\fR, and all references to 1619 \fB__real_\fR\fIsymbol\fR are modified to reference \fIsymbol\fR. The user is 1620 expected to provide an object containing the \fB__wrap_\fR\fIsymbol\fR 1621 function. This wrapper function can call \fB__real_\fR\fIsymbol\fR in order to 1622 reference the actual function being wrapped. 1623 .sp 1624 The following is an example of a wrapper for the \fBmalloc\fR(3C) function: 1625 .sp 1626 .in +2 1627 .nf 1628 void * 1629 __wrap_malloc(size_t c) 1630 { 1631 (void) printf("malloc called with %zu\en", c); 1632 return (__real_malloc(c)); 1633 } 1634 .fi 1635 .in -2 1636 1637 If you link other code with this file using \fB-z\fR \fBwrap=malloc\fR to 1638 compile all the objects, then all calls to \fBmalloc\fR will call the function 1639 \fB__wrap_malloc\fR instead. The call to \fB__real_malloc\fR will call the real 1640 \fBmalloc\fR function. 1641 .sp 1642 The real and wrapped functions should be maintained in separate source files. 1643 Otherwise, the compiler or assembler may resolve the call instead of leaving 1644 that operation for the link-editor to carry out, and prevent the wrap from 1645 occurring. 1646 .RE 1647 1648 .SH ENVIRONMENT VARIABLES 1649 .sp 1650 .ne 2 1651 .na 1652 \fB\fBLD_ALTEXEC\fR\fR 1653 .ad 1654 .sp .6 1655 .RS 4n 1656 An alternative link-editor path name. \fBld\fR executes, and passes control to 1657 this alternative link-editor. This environment variable provides a generic 1658 means of overriding the default link-editor that is called from the various 1659 compiler drivers. See the \fB-z altexec64\fR option. 1660 .RE 1661 1662 .sp 1663 .ne 2 1664 .na 1665 \fB\fBLD_LIBRARY_PATH\fR\fR 1666 .ad 1667 .sp .6 1668 .RS 4n 1669 A list of directories in which to search for the libraries specified using the 1670 \fB-l\fR option. Multiple directories are separated by a colon. In the most 1671 general case, this environment variable contains two directory lists separated 1672 by a semicolon: 1673 .sp 1674 .in +2 1675 .nf 1676 \fIdirlist1\fR\fB;\fR\fIdirlist2\fR 1677 .fi 1678 .in -2 1679 .sp 1680 1681 If \fBld\fR is called with any number of occurrences of \fB-L\fR, as in: 1682 .sp 1683 .in +2 1684 .nf 1685 \fBld ... -L\fIpath1\fR ... -L\fIpathn\fR ...\fR 1686 .fi 1687 .in -2 1688 .sp 1689 1690 then the search path ordering is: 1691 .sp 1692 .in +2 1693 .nf 1694 \fB\fIdirlist1 path1\fR ... \fIpathn dirlist2\fR LIBPATH\fR 1695 .fi 1696 .in -2 1697 .sp 1698 1699 When the list of directories does not contain a semicolon, the list is 1700 interpreted as \fIdirlist2\fR. 1701 .sp 1702 The \fBLD_LIBRARY_PATH\fR environment variable also affects the runtime linkers 1703 search for dynamic dependencies. 1704 .sp 1705 This environment variable can be specified with a _32 or _64 suffix. This makes 1706 the environment variable specific, respectively, to 32-bit or 64-bit processes 1707 and overrides any non-suffixed version of the environment variable that is in 1708 effect. 1709 .RE 1710 1711 .sp 1712 .ne 2 1713 .na 1714 \fB\fBLD_NOEXEC_64\fR\fR 1715 .ad 1716 .sp .6 1717 .RS 4n 1718 Suppresses the automatic execution of the 64-bit link-editor. By default, the 1719 link-editor executes the 64-bit version when the \fBELF\fR class of the first 1720 relocatable file identifies a 64-bit object. The 64-bit image that a 32-bit 1721 link-editor can create, has some limitations. However, some link-edits might 1722 find the use of the 32-bit link-editor faster. 1723 .RE 1724 1725 .sp 1726 .ne 2 1727 .na 1728 \fB\fBLD_OPTIONS\fR\fR 1729 .ad 1730 .sp .6 1731 .RS 4n 1732 A default set of options to \fBld\fR. \fBLD_OPTIONS\fR is interpreted by 1733 \fBld\fR just as though its value had been placed on the command line, 1734 immediately following the name used to invoke \fBld\fR, as in: 1735 .sp 1736 .in +2 1737 .nf 1738 \fBld $LD_OPTIONS ... \fIother-arguments\fR ...\fR 1739 .fi 1740 .in -2 1741 .sp 1742 1743 .RE 1744 1745 .sp 1746 .ne 2 1747 .na 1748 \fB\fBLD_RUN_PATH\fR\fR 1749 .ad 1750 .sp .6 1751 .RS 4n 1752 An alternative mechanism for specifying a runpath to the link-editor. See the 1753 \fB-R\fR option. If both \fBLD_RUN_PATH\fR and the \fB-R\fR option are 1754 specified, \fB-R\fR supersedes. 1755 .RE 1756 1757 .sp 1758 .ne 2 1759 .na 1760 \fB\fBSGS_SUPPORT\fR\fR 1761 .ad 1762 .sp .6 1763 .RS 4n 1764 Provides a colon-separated list of shared objects that are loaded with the 1765 link-editor and given information regarding the linking process. This 1766 environment variable can be specified with a _32 or _64 suffix. This makes the 1767 environment variable specific, respectively, to the 32-bit or 64-bit class of 1768 \fBld\fR and overrides any non-suffixed version of the environment variable 1769 that is in effect. See the \fB-S\fR option. 1770 .RE 1771 1772 .sp 1773 .LP 1774 Notice that environment variable-names that begin with the 1775 characters '\fBLD_\fR' are reserved for possible future enhancements to \fBld\fR and 1776 \fBld.so.1\fR(1). 1777 .SH FILES 1778 .sp 1779 .ne 2 1780 .na 1781 \fB\fBlib\fIx\fR.so\fR\fR 1782 .ad 1783 .RS 15n 1784 shared object libraries. 1785 .RE 1786 1787 .sp 1788 .ne 2 1789 .na 1790 \fB\fBlib\fIx\fR.a\fR\fR 1791 .ad 1792 .RS 15n 1793 archive libraries. 1794 .RE 1795 1796 .sp 1797 .ne 2 1798 .na 1799 \fB\fBa.out\fR\fR 1800 .ad 1801 .RS 15n 1802 default output file. 1803 .RE 1804 1805 .sp 1806 .ne 2 1807 .na 1808 \fB\fILIBPATH\fR\fR 1809 .ad 1810 .RS 15n 1811 For 32-bit libraries, the default search path is \fB/usr/ccs/lib\fR, followed 1812 by \fB/lib\fR, and finally \fB/usr/lib\fR. For 64-bit libraries, the default 1813 search path is \fB/lib/64\fR, followed by \fB/usr/lib/64\fR. 1814 .RE 1815 1816 .sp 1817 .ne 2 1818 .na 1819 \fB\fB/usr/lib/ld\fR\fR 1820 .ad 1821 .RS 15n 1822 A directory containing several \fBmapfiles\fR that can be used during 1823 link-editing. These \fBmapfiles\fR provide various capabilities, such as 1824 defining memory layouts, aligning bss, and defining non-executable stacks. 1825 .RE 1826 1827 .SH ATTRIBUTES 1828 .sp 1829 .LP 1830 See \fBattributes\fR(5) for descriptions of the following attributes: 1831 .sp 1832 1833 .sp 1834 .TS 1835 box; 1836 c | c 1837 l | l . 1838 ATTRIBUTE TYPE ATTRIBUTE VALUE 1839 _ 1840 Interface Stability Committed 1841 .TE 1842 1843 .SH SEE ALSO 1844 .sp 1845 .LP 1846 \fBas\fR(1), \fBcrle\fR(1), \fBgprof\fR(1), \fBld.so.1\fR(1), \fBldd\fR(1), 1847 \fBmcs\fR(1), \fBpvs\fR(1), \fBexec\fR(2), \fBstat\fR(2), \fBdlopen\fR(3C), 1848 \fBdldump\fR(3C), \fBelf\fR(3ELF), \fBar.h\fR(3HEAD), \fBa.out\fR(4), 1849 \fBattributes\fR(5) 1850 .sp 1851 .LP 1852 \fILinker and Libraries Guide\fR 1853 .SH NOTES 1854 .sp 1855 .LP 1856 Default options applied by \fBld\fR are maintained for historic reasons. In 1857 today's programming environment, where dynamic objects dominate, alternative 1858 defaults would often make more sense. However, historic defaults must be 1859 maintained to ensure compatibility with existing program development 1860 environments. Historic defaults are called out wherever possible in this 1861 manual. For a description of the current recommended options, see Appendix A, 1862 \fILink-Editor Quick Reference,\fR in \fILinker and Libraries Guide\fR. 1863 .sp 1864 .LP 1865 If the file being created by \fBld\fR already exists, the file is unlinked 1866 after all input files have been processed. A new file with the specified name 1867 is then created. This allows \fBld\fR to create a new version of the file, 1868 while simultaneously allowing existing processes that are accessing the old 1869 file contents to continue running. If the old file has no other links, the disk 1870 space of the removed file is freed when the last process referencing the file 1871 terminates. 1872 .sp 1873 .LP 1874 The behavior of \fBld\fR when the file being created already exists was changed 1875 with \fBSXCE\fR build \fB43\fR. In older versions, the existing file was 1876 rewritten in place, an approach with the potential to corrupt any running 1877 processes that is using the file. This change has an implication for output 1878 files that have multiple hard links in the file system. Previously, all links 1879 would remain intact, with all links accessing the new file contents. The new 1880 \fBld\fR behavior \fBbreaks\fR such links, with the result that only the 1881 specified output file name references the new file. All the other links 1882 continue to reference the old file. To ensure consistent behavior, applications 1883 that rely on multiple hard links to linker output files should explicitly 1884 remove and relink the other file names.