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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.