1LD(1)                        GNU Development Tools                       LD(1)
2
3
4

NAME

6       ld - The GNU linker
7

SYNOPSIS

9       ld [options] objfile ...
10

DESCRIPTION

12       ld combines a number of object and archive files, relocates their data
13       and ties up symbol references. Usually the last step in compiling a
14       program is to run ld.
15
16       ld accepts Linker Command Language files written in a superset of
17       AT&T's Link Editor Command Language syntax, to provide explicit and
18       total control over the linking process.
19
20       This man page does not describe the command language; see the ld entry
21       in "info" for full details on the command language and on other aspects
22       of the GNU linker.
23
24       This version of ld uses the general purpose BFD libraries to operate on
25       object files. This allows ld to read, combine, and write object files
26       in many different formats---for example, COFF or "a.out".  Different
27       formats may be linked together to produce any available kind of object
28       file.
29
30       Aside from its flexibility, the GNU linker is more helpful than other
31       linkers in providing diagnostic information.  Many linkers abandon
32       execution immediately upon encountering an error; whenever possible, ld
33       continues executing, allowing you to identify other errors (or, in some
34       cases, to get an output file in spite of the error).
35
36       The GNU linker ld is meant to cover a broad range of situations, and to
37       be as compatible as possible with other linkers.  As a result, you have
38       many choices to control its behavior.
39

OPTIONS

41       The linker supports a plethora of command-line options, but in actual
42       practice few of them are used in any particular context.  For instance,
43       a frequent use of ld is to link standard Unix object files on a
44       standard, supported Unix system.  On such a system, to link a file
45       "hello.o":
46
47               ld -o <output> /lib/crt0.o hello.o -lc
48
49       This tells ld to produce a file called output as the result of linking
50       the file "/lib/crt0.o" with "hello.o" and the library "libc.a", which
51       will come from the standard search directories.  (See the discussion of
52       the -l option below.)
53
54       Some of the command-line options to ld may be specified at any point in
55       the command line.  However, options which refer to files, such as -l or
56       -T, cause the file to be read at the point at which the option appears
57       in the command line, relative to the object files and other file
58       options.  Repeating non-file options with a different argument will
59       either have no further effect, or override prior occurrences (those
60       further to the left on the command line) of that option.  Options which
61       may be meaningfully specified more than once are noted in the
62       descriptions below.
63
64       Non-option arguments are object files or archives which are to be
65       linked together.  They may follow, precede, or be mixed in with
66       command-line options, except that an object file argument may not be
67       placed between an option and its argument.
68
69       Usually the linker is invoked with at least one object file, but you
70       can specify other forms of binary input files using -l, -R, and the
71       script command language.  If no binary input files at all are
72       specified, the linker does not produce any output, and issues the
73       message No input files.
74
75       If the linker cannot recognize the format of an object file, it will
76       assume that it is a linker script.  A script specified in this way
77       augments the main linker script used for the link (either the default
78       linker script or the one specified by using -T).  This feature permits
79       the linker to link against a file which appears to be an object or an
80       archive, but actually merely defines some symbol values, or uses
81       "INPUT" or "GROUP" to load other objects.  Specifying a script in this
82       way merely augments the main linker script, with the extra commands
83       placed after the main script; use the -T option to replace the default
84       linker script entirely, but note the effect of the "INSERT" command.
85
86       For options whose names are a single letter, option arguments must
87       either follow the option letter without intervening whitespace, or be
88       given as separate arguments immediately following the option that
89       requires them.
90
91       For options whose names are multiple letters, either one dash or two
92       can precede the option name; for example, -trace-symbol and
93       --trace-symbol are equivalent.  Note---there is one exception to this
94       rule.  Multiple letter options that start with a lower case 'o' can
95       only be preceded by two dashes.  This is to reduce confusion with the
96       -o option.  So for example -omagic sets the output file name to magic
97       whereas --omagic sets the NMAGIC flag on the output.
98
99       Arguments to multiple-letter options must either be separated from the
100       option name by an equals sign, or be given as separate arguments
101       immediately following the option that requires them.  For example,
102       --trace-symbol foo and --trace-symbol=foo are equivalent.  Unique
103       abbreviations of the names of multiple-letter options are accepted.
104
105       Note---if the linker is being invoked indirectly, via a compiler driver
106       (e.g. gcc) then all the linker command-line options should be prefixed
107       by -Wl, (or whatever is appropriate for the particular compiler driver)
108       like this:
109
110                 gcc -Wl,--start-group foo.o bar.o -Wl,--end-group
111
112       This is important, because otherwise the compiler driver program may
113       silently drop the linker options, resulting in a bad link.  Confusion
114       may also arise when passing options that require values through a
115       driver, as the use of a space between option and argument acts as a
116       separator, and causes the driver to pass only the option to the linker
117       and the argument to the compiler.  In this case, it is simplest to use
118       the joined forms of both single- and multiple-letter options, such as:
119
120                 gcc foo.o bar.o -Wl,-eENTRY -Wl,-Map=a.map
121
122       Here is a table of the generic command-line switches accepted by the
123       GNU linker:
124
125       @file
126           Read command-line options from file.  The options read are inserted
127           in place of the original @file option.  If file does not exist, or
128           cannot be read, then the option will be treated literally, and not
129           removed.
130
131           Options in file are separated by whitespace.  A whitespace
132           character may be included in an option by surrounding the entire
133           option in either single or double quotes.  Any character (including
134           a backslash) may be included by prefixing the character to be
135           included with a backslash.  The file may itself contain additional
136           @file options; any such options will be processed recursively.
137
138       -a keyword
139           This option is supported for HP/UX compatibility.  The keyword
140           argument must be one of the strings archive, shared, or default.
141           -aarchive is functionally equivalent to -Bstatic, and the other two
142           keywords are functionally equivalent to -Bdynamic.  This option may
143           be used any number of times.
144
145       --audit AUDITLIB
146           Adds AUDITLIB to the "DT_AUDIT" entry of the dynamic section.
147           AUDITLIB is not checked for existence, nor will it use the
148           DT_SONAME specified in the library.  If specified multiple times
149           "DT_AUDIT" will contain a colon separated list of audit interfaces
150           to use. If the linker finds an object with an audit entry while
151           searching for shared libraries, it will add a corresponding
152           "DT_DEPAUDIT" entry in the output file.  This option is only
153           meaningful on ELF platforms supporting the rtld-audit interface.
154
155       -b input-format
156       --format=input-format
157           ld may be configured to support more than one kind of object file.
158           If your ld is configured this way, you can use the -b option to
159           specify the binary format for input object files that follow this
160           option on the command line.  Even when ld is configured to support
161           alternative object formats, you don't usually need to specify this,
162           as ld should be configured to expect as a default input format the
163           most usual format on each machine.  input-format is a text string,
164           the name of a particular format supported by the BFD libraries.
165           (You can list the available binary formats with objdump -i.)
166
167           You may want to use this option if you are linking files with an
168           unusual binary format.  You can also use -b to switch formats
169           explicitly (when linking object files of different formats), by
170           including -b input-format before each group of object files in a
171           particular format.
172
173           The default format is taken from the environment variable
174           "GNUTARGET".
175
176           You can also define the input format from a script, using the
177           command "TARGET";
178
179       -c MRI-commandfile
180       --mri-script=MRI-commandfile
181           For compatibility with linkers produced by MRI, ld accepts script
182           files written in an alternate, restricted command language,
183           described in the MRI Compatible Script Files section of GNU ld
184           documentation.  Introduce MRI script files with the option -c; use
185           the -T option to run linker scripts written in the general-purpose
186           ld scripting language.  If MRI-cmdfile does not exist, ld looks for
187           it in the directories specified by any -L options.
188
189       -d
190       -dc
191       -dp These three options are equivalent; multiple forms are supported
192           for compatibility with other linkers.  They assign space to common
193           symbols even if a relocatable output file is specified (with -r).
194           The script command "FORCE_COMMON_ALLOCATION" has the same effect.
195
196       --depaudit AUDITLIB
197       -P AUDITLIB
198           Adds AUDITLIB to the "DT_DEPAUDIT" entry of the dynamic section.
199           AUDITLIB is not checked for existence, nor will it use the
200           DT_SONAME specified in the library.  If specified multiple times
201           "DT_DEPAUDIT" will contain a colon separated list of audit
202           interfaces to use.  This option is only meaningful on ELF platforms
203           supporting the rtld-audit interface.  The -P option is provided for
204           Solaris compatibility.
205
206       --enable-non-contiguous-regions
207           This option avoids generating an error if an input section does not
208           fit a matching output section. The linker tries to allocate the
209           input section to subseque nt matching output sections, and
210           generates an error only if no output section is large enough.  This
211           is useful when several non-contiguous memory regions are available
212           and the input section does not require a particular one.  The order
213           in which input sections are evaluated does not change, for
214           instance:
215
216                     MEMORY {
217                       MEM1 (rwx) : ORIGIN : 0x1000, LENGTH = 0x14
218                       MEM2 (rwx) : ORIGIN : 0x1000, LENGTH = 0x40
219                       MEM3 (rwx) : ORIGIN : 0x2000, LENGTH = 0x40
220                     }
221                     SECTIONS {
222                       mem1 : { *(.data.*); } > MEM1
223                       mem2 : { *(.data.*); } > MEM2
224                       mem3 : { *(.data.*); } > MEM2
225                     }
226
227                     with input sections:
228                     .data.1: size 8
229                     .data.2: size 0x10
230                     .data.3: size 4
231
232                     results in .data.1 affected to mem1, and .data.2 and .data.3
233                     affected to mem2, even though .data.3 would fit in mem3.
234
235           This option is incompatible with INSERT statements because it
236           changes the way input sections are mapped to output sections.
237
238       --enable-non-contiguous-regions-warnings
239           This option enables warnings when "--enable-non-contiguous-regions"
240           allows possibly unexpected matches in sections mapping, potentially
241           leading to silently discarding a section instead of failing because
242           it does not fit any output region.
243
244       -e entry
245       --entry=entry
246           Use entry as the explicit symbol for beginning execution of your
247           program, rather than the default entry point.  If there is no
248           symbol named entry, the linker will try to parse entry as a number,
249           and use that as the entry address (the number will be interpreted
250           in base 10; you may use a leading 0x for base 16, or a leading 0
251           for base 8).
252
253       --exclude-libs lib,lib,...
254           Specifies a list of archive libraries from which symbols should not
255           be automatically exported.  The library names may be delimited by
256           commas or colons.  Specifying "--exclude-libs ALL" excludes symbols
257           in all archive libraries from automatic export.  This option is
258           available only for the i386 PE targeted port of the linker and for
259           ELF targeted ports.  For i386 PE, symbols explicitly listed in a
260           .def file are still exported, regardless of this option.  For ELF
261           targeted ports, symbols affected by this option will be treated as
262           hidden.
263
264       --exclude-modules-for-implib module,module,...
265           Specifies a list of object files or archive members, from which
266           symbols should not be automatically exported, but which should be
267           copied wholesale into the import library being generated during the
268           link.  The module names may be delimited by commas or colons, and
269           must match exactly the filenames used by ld to open the files; for
270           archive members, this is simply the member name, but for object
271           files the name listed must include and match precisely any path
272           used to specify the input file on the linker's command-line.  This
273           option is available only for the i386 PE targeted port of the
274           linker.  Symbols explicitly listed in a .def file are still
275           exported, regardless of this option.
276
277       -E
278       --export-dynamic
279       --no-export-dynamic
280           When creating a dynamically linked executable, using the -E option
281           or the --export-dynamic option causes the linker to add all symbols
282           to the dynamic symbol table.  The dynamic symbol table is the set
283           of symbols which are visible from dynamic objects at run time.
284
285           If you do not use either of these options (or use the
286           --no-export-dynamic option to restore the default behavior), the
287           dynamic symbol table will normally contain only those symbols which
288           are referenced by some dynamic object mentioned in the link.
289
290           If you use "dlopen" to load a dynamic object which needs to refer
291           back to the symbols defined by the program, rather than some other
292           dynamic object, then you will probably need to use this option when
293           linking the program itself.
294
295           You can also use the dynamic list to control what symbols should be
296           added to the dynamic symbol table if the output format supports it.
297           See the description of --dynamic-list.
298
299           Note that this option is specific to ELF targeted ports.  PE
300           targets support a similar function to export all symbols from a DLL
301           or EXE; see the description of --export-all-symbols below.
302
303       --export-dynamic-symbol=glob
304           When creating a dynamically linked executable, symbols matching
305           glob will be added to the dynamic symbol table. When creating a
306           shared library, references to symbols matching glob will not be
307           bound to the definitions within the shared library. This option is
308           a no-op when creating a shared library and -Bsymbolic or
309           --dynamic-list are not specified. This option is only meaningful on
310           ELF platforms which support shared libraries.
311
312       --export-dynamic-symbol-list=file
313           Specify a --export-dynamic-symbol for each pattern in the file.
314           The format of the file is the same as the version node without
315           scope and node name.  See VERSION for more information.
316
317       -EB Link big-endian objects.  This affects the default output format.
318
319       -EL Link little-endian objects.  This affects the default output
320           format.
321
322       -f name
323       --auxiliary=name
324           When creating an ELF shared object, set the internal DT_AUXILIARY
325           field to the specified name.  This tells the dynamic linker that
326           the symbol table of the shared object should be used as an
327           auxiliary filter on the symbol table of the shared object name.
328
329           If you later link a program against this filter object, then, when
330           you run the program, the dynamic linker will see the DT_AUXILIARY
331           field.  If the dynamic linker resolves any symbols from the filter
332           object, it will first check whether there is a definition in the
333           shared object name.  If there is one, it will be used instead of
334           the definition in the filter object.  The shared object name need
335           not exist.  Thus the shared object name may be used to provide an
336           alternative implementation of certain functions, perhaps for
337           debugging or for machine-specific performance.
338
339           This option may be specified more than once.  The DT_AUXILIARY
340           entries will be created in the order in which they appear on the
341           command line.
342
343       -F name
344       --filter=name
345           When creating an ELF shared object, set the internal DT_FILTER
346           field to the specified name.  This tells the dynamic linker that
347           the symbol table of the shared object which is being created should
348           be used as a filter on the symbol table of the shared object name.
349
350           If you later link a program against this filter object, then, when
351           you run the program, the dynamic linker will see the DT_FILTER
352           field.  The dynamic linker will resolve symbols according to the
353           symbol table of the filter object as usual, but it will actually
354           link to the definitions found in the shared object name.  Thus the
355           filter object can be used to select a subset of the symbols
356           provided by the object name.
357
358           Some older linkers used the -F option throughout a compilation
359           toolchain for specifying object-file format for both input and
360           output object files.  The GNU linker uses other mechanisms for this
361           purpose: the -b, --format, --oformat options, the "TARGET" command
362           in linker scripts, and the "GNUTARGET" environment variable.  The
363           GNU linker will ignore the -F option when not creating an ELF
364           shared object.
365
366       -fini=name
367           When creating an ELF executable or shared object, call NAME when
368           the executable or shared object is unloaded, by setting DT_FINI to
369           the address of the function.  By default, the linker uses "_fini"
370           as the function to call.
371
372       -g  Ignored.  Provided for compatibility with other tools.
373
374       -G value
375       --gpsize=value
376           Set the maximum size of objects to be optimized using the GP
377           register to size.  This is only meaningful for object file formats
378           such as MIPS ELF that support putting large and small objects into
379           different sections.  This is ignored for other object file formats.
380
381       -h name
382       -soname=name
383           When creating an ELF shared object, set the internal DT_SONAME
384           field to the specified name.  When an executable is linked with a
385           shared object which has a DT_SONAME field, then when the executable
386           is run the dynamic linker will attempt to load the shared object
387           specified by the DT_SONAME field rather than using the file name
388           given to the linker.
389
390       -i  Perform an incremental link (same as option -r).
391
392       -init=name
393           When creating an ELF executable or shared object, call NAME when
394           the executable or shared object is loaded, by setting DT_INIT to
395           the address of the function.  By default, the linker uses "_init"
396           as the function to call.
397
398       -l namespec
399       --library=namespec
400           Add the archive or object file specified by namespec to the list of
401           files to link.  This option may be used any number of times.  If
402           namespec is of the form :filename, ld will search the library path
403           for a file called filename, otherwise it will search the library
404           path for a file called libnamespec.a.
405
406           On systems which support shared libraries, ld may also search for
407           files other than libnamespec.a.  Specifically, on ELF and SunOS
408           systems, ld will search a directory for a library called
409           libnamespec.so before searching for one called libnamespec.a.  (By
410           convention, a ".so" extension indicates a shared library.)  Note
411           that this behavior does not apply to :filename, which always
412           specifies a file called filename.
413
414           The linker will search an archive only once, at the location where
415           it is specified on the command line.  If the archive defines a
416           symbol which was undefined in some object which appeared before the
417           archive on the command line, the linker will include the
418           appropriate file(s) from the archive.  However, an undefined symbol
419           in an object appearing later on the command line will not cause the
420           linker to search the archive again.
421
422           See the -( option for a way to force the linker to search archives
423           multiple times.
424
425           You may list the same archive multiple times on the command line.
426
427           This type of archive searching is standard for Unix linkers.
428           However, if you are using ld on AIX, note that it is different from
429           the behaviour of the AIX linker.
430
431       -L searchdir
432       --library-path=searchdir
433           Add path searchdir to the list of paths that ld will search for
434           archive libraries and ld control scripts.  You may use this option
435           any number of times.  The directories are searched in the order in
436           which they are specified on the command line.  Directories
437           specified on the command line are searched before the default
438           directories.  All -L options apply to all -l options, regardless of
439           the order in which the options appear.  -L options do not affect
440           how ld searches for a linker script unless -T option is specified.
441
442           If searchdir begins with "=" or $SYSROOT, then this prefix will be
443           replaced by the sysroot prefix, controlled by the --sysroot option,
444           or specified when the linker is configured.
445
446           The default set of paths searched (without being specified with -L)
447           depends on which emulation mode ld is using, and in some cases also
448           on how it was configured.
449
450           The paths can also be specified in a link script with the
451           "SEARCH_DIR" command.  Directories specified this way are searched
452           at the point in which the linker script appears in the command
453           line.
454
455       -m emulation
456           Emulate the emulation linker.  You can list the available
457           emulations with the --verbose or -V options.
458
459           If the -m option is not used, the emulation is taken from the
460           "LDEMULATION" environment variable, if that is defined.
461
462           Otherwise, the default emulation depends upon how the linker was
463           configured.
464
465       -M
466       --print-map
467           Print a link map to the standard output.  A link map provides
468           information about the link, including the following:
469
470           •   Where object files are mapped into memory.
471
472           •   How common symbols are allocated.
473
474           •   All archive members included in the link, with a mention of the
475               symbol which caused the archive member to be brought in.
476
477           •   The values assigned to symbols.
478
479               Note - symbols whose values are computed by an expression which
480               involves a reference to a previous value of the same symbol may
481               not have correct result displayed in the link map.  This is
482               because the linker discards intermediate results and only
483               retains the final value of an expression.  Under such
484               circumstances the linker will display the final value enclosed
485               by square brackets.  Thus for example a linker script
486               containing:
487
488                          foo = 1
489                          foo = foo * 4
490                          foo = foo + 8
491
492               will produce the following output in the link map if the -M
493               option is used:
494
495                          0x00000001                foo = 0x1
496                          [0x0000000c]                foo = (foo * 0x4)
497                          [0x0000000c]                foo = (foo + 0x8)
498
499               See Expressions for more information about expressions in
500               linker scripts.
501
502           •   How GNU properties are merged.
503
504               When the linker merges input .note.gnu.property sections into
505               one output .note.gnu.property section, some properties are
506               removed or updated.  These actions are reported in the link
507               map.  For example:
508
509                       Removed property 0xc0000002 to merge foo.o (0x1) and bar.o (not found)
510
511               This indicates that property 0xc0000002 is removed from output
512               when merging properties in  foo.o, whose property 0xc0000002
513               value is 0x1, and bar.o, which doesn't have property
514               0xc0000002.
515
516                       Updated property 0xc0010001 (0x1) to merge foo.o (0x1) and bar.o (0x1)
517
518               This indicates that property 0xc0010001 value is updated to 0x1
519               in output when merging properties in  foo.o, whose 0xc0010001
520               property value is 0x1, and bar.o, whose 0xc0010001 property
521               value is 0x1.
522
523       --print-map-discarded
524       --no-print-map-discarded
525           Print (or do not print) the list of discarded and garbage collected
526           sections in the link map.  Enabled by default.
527
528       -n
529       --nmagic
530           Turn off page alignment of sections, and disable linking against
531           shared libraries.  If the output format supports Unix style magic
532           numbers, mark the output as "NMAGIC".
533
534       -N
535       --omagic
536           Set the text and data sections to be readable and writable.  Also,
537           do not page-align the data segment, and disable linking against
538           shared libraries.  If the output format supports Unix style magic
539           numbers, mark the output as "OMAGIC". Note: Although a writable
540           text section is allowed for PE-COFF targets, it does not conform to
541           the format specification published by Microsoft.
542
543       --no-omagic
544           This option negates most of the effects of the -N option.  It sets
545           the text section to be read-only, and forces the data segment to be
546           page-aligned.  Note - this option does not enable linking against
547           shared libraries.  Use -Bdynamic for this.
548
549       -o output
550       --output=output
551           Use output as the name for the program produced by ld; if this
552           option is not specified, the name a.out is used by default.  The
553           script command "OUTPUT" can also specify the output file name.
554
555       --dependency-file=depfile
556           Write a dependency file to depfile.  This file contains a rule
557           suitable for "make" describing the output file and all the input
558           files that were read to produce it.  The output is similar to the
559           compiler's output with -M -MP.  Note that there is no option like
560           the compiler's -MM, to exclude "system files" (which is not a well-
561           specified concept in the linker, unlike "system headers" in the
562           compiler).  So the output from --dependency-file is always specific
563           to the exact state of the installation where it was produced, and
564           should not be copied into distributed makefiles without careful
565           editing.
566
567       -O level
568           If level is a numeric values greater than zero ld optimizes the
569           output.  This might take significantly longer and therefore
570           probably should only be enabled for the final binary.  At the
571           moment this option only affects ELF shared library generation.
572           Future releases of the linker may make more use of this option.
573           Also currently there is no difference in the linker's behaviour for
574           different non-zero values of this option.  Again this may change
575           with future releases.
576
577       -plugin name
578           Involve a plugin in the linking process.  The name parameter is the
579           absolute filename of the plugin.  Usually this parameter is
580           automatically added by the complier, when using link time
581           optimization, but users can also add their own plugins if they so
582           wish.
583
584           Note that the location of the compiler originated plugins is
585           different from the place where the ar, nm and ranlib programs
586           search for their plugins.  In order for those commands to make use
587           of a compiler based plugin it must first be copied into the
588           ${libdir}/bfd-plugins directory.  All gcc based linker plugins are
589           backward compatible, so it is sufficient to just copy in the newest
590           one.
591
592       --push-state
593           The --push-state allows one to preserve the current state of the
594           flags which govern the input file handling so that they can all be
595           restored with one corresponding --pop-state option.
596
597           The option which are covered are: -Bdynamic, -Bstatic, -dn, -dy,
598           -call_shared, -non_shared, -static, -N, -n, --whole-archive,
599           --no-whole-archive, -r, -Ur, --copy-dt-needed-entries,
600           --no-copy-dt-needed-entries, --as-needed, --no-as-needed, and -a.
601
602           One target for this option are specifications for pkg-config.  When
603           used with the --libs option all possibly needed libraries are
604           listed and then possibly linked with all the time.  It is better to
605           return something as follows:
606
607                   -Wl,--push-state,--as-needed -libone -libtwo -Wl,--pop-state
608
609       --pop-state
610           Undoes the effect of --push-state, restores the previous values of
611           the flags governing input file handling.
612
613       -q
614       --emit-relocs
615           Leave relocation sections and contents in fully linked executables.
616           Post link analysis and optimization tools may need this information
617           in order to perform correct modifications of executables.  This
618           results in larger executables.
619
620           This option is currently only supported on ELF platforms.
621
622       --force-dynamic
623           Force the output file to have dynamic sections.  This option is
624           specific to VxWorks targets.
625
626       -r
627       --relocatable
628           Generate relocatable output---i.e., generate an output file that
629           can in turn serve as input to ld.  This is often called partial
630           linking.  As a side effect, in environments that support standard
631           Unix magic numbers, this option also sets the output file's magic
632           number to "OMAGIC".  If this option is not specified, an absolute
633           file is produced.  When linking C++ programs, this option will not
634           resolve references to constructors; to do that, use -Ur.
635
636           When an input file does not have the same format as the output
637           file, partial linking is only supported if that input file does not
638           contain any relocations.  Different output formats can have further
639           restrictions; for example some "a.out"-based formats do not support
640           partial linking with input files in other formats at all.
641
642           This option does the same thing as -i.
643
644       -R filename
645       --just-symbols=filename
646           Read symbol names and their addresses from filename, but do not
647           relocate it or include it in the output.  This allows your output
648           file to refer symbolically to absolute locations of memory defined
649           in other programs.  You may use this option more than once.
650
651           For compatibility with other ELF linkers, if the -R option is
652           followed by a directory name, rather than a file name, it is
653           treated as the -rpath option.
654
655       -s
656       --strip-all
657           Omit all symbol information from the output file.
658
659       -S
660       --strip-debug
661           Omit debugger symbol information (but not all symbols) from the
662           output file.
663
664       --strip-discarded
665       --no-strip-discarded
666           Omit (or do not omit) global symbols defined in discarded sections.
667           Enabled by default.
668
669       -t
670       --trace
671           Print the names of the input files as ld processes them.  If -t is
672           given twice then members within archives are also printed.  -t
673           output is useful to generate a list of all the object files and
674           scripts involved in linking, for example, when packaging files for
675           a linker bug report.
676
677       -T scriptfile
678       --script=scriptfile
679           Use scriptfile as the linker script.  This script replaces ld's
680           default linker script (rather than adding to it), so commandfile
681           must specify everything necessary to describe the output file.
682           If scriptfile does not exist in the current directory, "ld" looks
683           for it in the directories specified by any preceding -L options.
684           Multiple -T options accumulate.
685
686       -dT scriptfile
687       --default-script=scriptfile
688           Use scriptfile as the default linker script.
689
690           This option is similar to the --script option except that
691           processing of the script is delayed until after the rest of the
692           command line has been processed.  This allows options placed after
693           the --default-script option on the command line to affect the
694           behaviour of the linker script, which can be important when the
695           linker command line cannot be directly controlled by the user.  (eg
696           because the command line is being constructed by another tool, such
697           as gcc).
698
699       -u symbol
700       --undefined=symbol
701           Force symbol to be entered in the output file as an undefined
702           symbol.  Doing this may, for example, trigger linking of additional
703           modules from standard libraries.  -u may be repeated with different
704           option arguments to enter additional undefined symbols.  This
705           option is equivalent to the "EXTERN" linker script command.
706
707           If this option is being used to force additional modules to be
708           pulled into the link, and if it is an error for the symbol to
709           remain undefined, then the option --require-defined should be used
710           instead.
711
712       --require-defined=symbol
713           Require that symbol is defined in the output file.  This option is
714           the same as option --undefined except that if symbol is not defined
715           in the output file then the linker will issue an error and exit.
716           The same effect can be achieved in a linker script by using
717           "EXTERN", "ASSERT" and "DEFINED" together.  This option can be used
718           multiple times to require additional symbols.
719
720       -Ur For anything other than C++ programs, this option is equivalent to
721           -r: it generates relocatable output---i.e., an output file that can
722           in turn serve as input to ld.  When linking C++ programs, -Ur does
723           resolve references to constructors, unlike -r.  It does not work to
724           use -Ur on files that were themselves linked with -Ur; once the
725           constructor table has been built, it cannot be added to.  Use -Ur
726           only for the last partial link, and -r for the others.
727
728       --orphan-handling=MODE
729           Control how orphan sections are handled.  An orphan section is one
730           not specifically mentioned in a linker script.
731
732           MODE can have any of the following values:
733
734           "place"
735               Orphan sections are placed into a suitable output section
736               following the strategy described in Orphan Sections.  The
737               option --unique also affects how sections are placed.
738
739           "discard"
740               All orphan sections are discarded, by placing them in the
741               /DISCARD/ section.
742
743           "warn"
744               The linker will place the orphan section as for "place" and
745               also issue a warning.
746
747           "error"
748               The linker will exit with an error if any orphan section is
749               found.
750
751           The default if --orphan-handling is not given is "place".
752
753       --unique[=SECTION]
754           Creates a separate output section for every input section matching
755           SECTION, or if the optional wildcard SECTION argument is missing,
756           for every orphan input section.  An orphan section is one not
757           specifically mentioned in a linker script.  You may use this option
758           multiple times on the command line;  It prevents the normal merging
759           of input sections with the same name, overriding output section
760           assignments in a linker script.
761
762       -v
763       --version
764       -V  Display the version number for ld.  The -V option also lists the
765           supported emulations.
766
767       -x
768       --discard-all
769           Delete all local symbols.
770
771       -X
772       --discard-locals
773           Delete all temporary local symbols.  (These symbols start with
774           system-specific local label prefixes, typically .L for ELF systems
775           or L for traditional a.out systems.)
776
777       -y symbol
778       --trace-symbol=symbol
779           Print the name of each linked file in which symbol appears.  This
780           option may be given any number of times.  On many systems it is
781           necessary to prepend an underscore.
782
783           This option is useful when you have an undefined symbol in your
784           link but don't know where the reference is coming from.
785
786       -Y path
787           Add path to the default library search path.  This option exists
788           for Solaris compatibility.
789
790       -z keyword
791           The recognized keywords are:
792
793           call-nop=prefix-addr
794           call-nop=suffix-nop
795           call-nop=prefix-byte
796           call-nop=suffix-byte
797               Specify the 1-byte "NOP" padding when transforming indirect
798               call to a locally defined function, foo, via its GOT slot.
799               call-nop=prefix-addr generates "0x67 call foo".
800               call-nop=suffix-nop generates "call foo 0x90".
801               call-nop=prefix-byte generates "byte call foo".
802               call-nop=suffix-byte generates "call foo byte".  Supported for
803               i386 and x86_64.
804
805           cet-report=none
806           cet-report=warning
807           cet-report=error
808               Specify how to report the missing
809               GNU_PROPERTY_X86_FEATURE_1_IBT and
810               GNU_PROPERTY_X86_FEATURE_1_SHSTK properties in input
811               .note.gnu.property section.  cet-report=none, which is the
812               default, will make the linker not report missing properties in
813               input files.  cet-report=warning will make the linker issue a
814               warning for missing properties in input files.
815               cet-report=error will make the linker issue an error for
816               missing properties in input files.  Note that ibt will turn off
817               the missing GNU_PROPERTY_X86_FEATURE_1_IBT property report and
818               shstk will turn off the missing
819               GNU_PROPERTY_X86_FEATURE_1_SHSTK property report.  Supported
820               for Linux/i386 and Linux/x86_64.
821
822           combreloc
823           nocombreloc
824               Combine multiple dynamic relocation sections and sort to
825               improve dynamic symbol lookup caching.  Do not do this if
826               nocombreloc.
827
828           common
829           nocommon
830               Generate common symbols with STT_COMMON type during a
831               relocatable link.  Use STT_OBJECT type if nocommon.
832
833           common-page-size=value
834               Set the page size most commonly used to value.  Memory image
835               layout will be optimized to minimize memory pages if the system
836               is using pages of this size.
837
838           defs
839               Report unresolved symbol references from regular object files.
840               This is done even if the linker is creating a non-symbolic
841               shared library.  This option is the inverse of -z undefs.
842
843           dynamic-undefined-weak
844           nodynamic-undefined-weak
845               Make undefined weak symbols dynamic when building a dynamic
846               object, if they are referenced from a regular object file and
847               not forced local by symbol visibility or versioning.  Do not
848               make them dynamic if nodynamic-undefined-weak.  If neither
849               option is given, a target may default to either option being in
850               force, or make some other selection of undefined weak symbols
851               dynamic.  Not all targets support these options.
852
853           execstack
854               Marks the object as requiring executable stack.
855
856           global
857               This option is only meaningful when building a shared object.
858               It makes the symbols defined by this shared object available
859               for symbol resolution of subsequently loaded libraries.
860
861           globalaudit
862               This option is only meaningful when building a dynamic
863               executable.  This option marks the executable as requiring
864               global auditing by setting the "DF_1_GLOBAUDIT" bit in the
865               "DT_FLAGS_1" dynamic tag.  Global auditing requires that any
866               auditing library defined via the --depaudit or -P command-line
867               options be run for all dynamic objects loaded by the
868               application.
869
870           ibtplt
871               Generate Intel Indirect Branch Tracking (IBT) enabled PLT
872               entries.  Supported for Linux/i386 and Linux/x86_64.
873
874           ibt Generate GNU_PROPERTY_X86_FEATURE_1_IBT in .note.gnu.property
875               section to indicate compatibility with IBT.  This also implies
876               ibtplt.  Supported for Linux/i386 and Linux/x86_64.
877
878           indirect-extern-access
879           noindirect-extern-access
880               Generate GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS in
881               .note.gnu.property section to indicate that object file
882               requires canonical function pointers and cannot be used with
883               copy relocation.  This option also implies noextern-protected-
884               data and nocopyreloc.  Supported for i386 and x86-64.
885
886               noindirect-extern-access removes
887               GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS from
888               .note.gnu.property section.
889
890           initfirst
891               This option is only meaningful when building a shared object.
892               It marks the object so that its runtime initialization will
893               occur before the runtime initialization of any other objects
894               brought into the process at the same time.  Similarly the
895               runtime finalization of the object will occur after the runtime
896               finalization of any other objects.
897
898           interpose
899               Specify that the dynamic loader should modify its symbol search
900               order so that symbols in this shared library interpose all
901               other shared libraries not so marked.
902
903           unique
904           nounique
905               When generating a shared library or other dynamically loadable
906               ELF object mark it as one that should (by default) only ever be
907               loaded once, and only in the main namespace (when using
908               "dlmopen"). This is primarily used to mark fundamental
909               libraries such as libc, libpthread et al which do not usually
910               function correctly unless they are the sole instances of
911               themselves. This behaviour can be overridden by the "dlmopen"
912               caller and does not apply to certain loading mechanisms (such
913               as audit libraries).
914
915           lam-u48
916               Generate GNU_PROPERTY_X86_FEATURE_1_LAM_U48 in
917               .note.gnu.property section to indicate compatibility with Intel
918               LAM_U48.  Supported for Linux/x86_64.
919
920           lam-u57
921               Generate GNU_PROPERTY_X86_FEATURE_1_LAM_U57 in
922               .note.gnu.property section to indicate compatibility with Intel
923               LAM_U57.  Supported for Linux/x86_64.
924
925           lam-u48-report=none
926           lam-u48-report=warning
927           lam-u48-report=error
928               Specify how to report the missing
929               GNU_PROPERTY_X86_FEATURE_1_LAM_U48 property in input
930               .note.gnu.property section.  lam-u48-report=none, which is the
931               default, will make the linker not report missing properties in
932               input files.  lam-u48-report=warning will make the linker issue
933               a warning for missing properties in input files.
934               lam-u48-report=error will make the linker issue an error for
935               missing properties in input files.  Supported for Linux/x86_64.
936
937           lam-u57-report=none
938           lam-u57-report=warning
939           lam-u57-report=error
940               Specify how to report the missing
941               GNU_PROPERTY_X86_FEATURE_1_LAM_U57 property in input
942               .note.gnu.property section.  lam-u57-report=none, which is the
943               default, will make the linker not report missing properties in
944               input files.  lam-u57-report=warning will make the linker issue
945               a warning for missing properties in input files.
946               lam-u57-report=error will make the linker issue an error for
947               missing properties in input files.  Supported for Linux/x86_64.
948
949           lam-report=none
950           lam-report=warning
951           lam-report=error
952               Specify how to report the missing
953               GNU_PROPERTY_X86_FEATURE_1_LAM_U48 and
954               GNU_PROPERTY_X86_FEATURE_1_LAM_U57 properties in input
955               .note.gnu.property section.  lam-report=none, which is the
956               default, will make the linker not report missing properties in
957               input files.  lam-report=warning will make the linker issue a
958               warning for missing properties in input files.
959               lam-report=error will make the linker issue an error for
960               missing properties in input files.  Supported for Linux/x86_64.
961
962           lazy
963               When generating an executable or shared library, mark it to
964               tell the dynamic linker to defer function call resolution to
965               the point when the function is called (lazy binding), rather
966               than at load time.  Lazy binding is the default.
967
968           loadfltr
969               Specify that the object's filters be processed immediately at
970               runtime.
971
972           max-page-size=value
973               Set the maximum memory page size supported to value.
974
975           muldefs
976               Allow multiple definitions.
977
978           nocopyreloc
979               Disable linker generated .dynbss variables used in place of
980               variables defined in shared libraries.  May result in dynamic
981               text relocations.
982
983           nodefaultlib
984               Specify that the dynamic loader search for dependencies of this
985               object should ignore any default library search paths.
986
987           nodelete
988               Specify that the object shouldn't be unloaded at runtime.
989
990           nodlopen
991               Specify that the object is not available to "dlopen".
992
993           nodump
994               Specify that the object can not be dumped by "dldump".
995
996           noexecstack
997               Marks the object as not requiring executable stack.
998
999           noextern-protected-data
1000               Don't treat protected data symbols as external when building a
1001               shared library.  This option overrides the linker backend
1002               default.  It can be used to work around incorrect relocations
1003               against protected data symbols generated by compiler.  Updates
1004               on protected data symbols by another module aren't visible to
1005               the resulting shared library.  Supported for i386 and x86-64.
1006
1007           noreloc-overflow
1008               Disable relocation overflow check.  This can be used to disable
1009               relocation overflow check if there will be no dynamic
1010               relocation overflow at run-time.  Supported for x86_64.
1011
1012           now When generating an executable or shared library, mark it to
1013               tell the dynamic linker to resolve all symbols when the program
1014               is started, or when the shared library is loaded by dlopen,
1015               instead of deferring function call resolution to the point when
1016               the function is first called.
1017
1018           origin
1019               Specify that the object requires $ORIGIN handling in paths.
1020
1021           pack-relative-relocs
1022           nopack-relative-relocs
1023               Generate compact relative relocation in position-independent
1024               executable and shared library.  It adds "DT_RELR", "DT_RELRSZ"
1025               and "DT_RELRENT" entries to the dynamic section.  It is ignored
1026               when building position-dependent executable and relocatable
1027               output.  nopack-relative-relocs is the default, which disables
1028               compact relative relocation.  When linked against the GNU C
1029               Library, a GLIBC_ABI_DT_RELR symbol version dependency on the
1030               shared C Library is added to the output.  Supported for i386
1031               and x86-64.
1032
1033           relro
1034           norelro
1035               Create an ELF "PT_GNU_RELRO" segment header in the object.
1036               This specifies a memory segment that should be made read-only
1037               after relocation, if supported.  Specifying common-page-size
1038               smaller than the system page size will render this protection
1039               ineffective.  Don't create an ELF "PT_GNU_RELRO" segment if
1040               norelro.
1041
1042           report-relative-reloc
1043               Report dynamic relative relocations generated by linker.
1044               Supported for Linux/i386 and Linux/x86_64.
1045
1046           separate-code
1047           noseparate-code
1048               Create separate code "PT_LOAD" segment header in the object.
1049               This specifies a memory segment that should contain only
1050               instructions and must be in wholly disjoint pages from any
1051               other data.  Don't create separate code "PT_LOAD" segment if
1052               noseparate-code is used.
1053
1054           shstk
1055               Generate GNU_PROPERTY_X86_FEATURE_1_SHSTK in .note.gnu.property
1056               section to indicate compatibility with Intel Shadow Stack.
1057               Supported for Linux/i386 and Linux/x86_64.
1058
1059           stack-size=value
1060               Specify a stack size for an ELF "PT_GNU_STACK" segment.
1061               Specifying zero will override any default non-zero sized
1062               "PT_GNU_STACK" segment creation.
1063
1064           start-stop-gc
1065           nostart-stop-gc
1066               When --gc-sections is in effect, a reference from a retained
1067               section to "__start_SECNAME" or "__stop_SECNAME" causes all
1068               input sections named "SECNAME" to also be retained, if
1069               "SECNAME" is representable as a C identifier and either
1070               "__start_SECNAME" or "__stop_SECNAME" is synthesized by the
1071               linker.  -z start-stop-gc disables this effect, allowing
1072               sections to be garbage collected as if the special synthesized
1073               symbols were not defined.  -z start-stop-gc has no effect on a
1074               definition of "__start_SECNAME" or "__stop_SECNAME" in an
1075               object file or linker script.  Such a definition will prevent
1076               the linker providing a synthesized "__start_SECNAME" or
1077               "__stop_SECNAME" respectively, and therefore the special
1078               treatment by garbage collection for those references.
1079
1080           start-stop-visibility=value
1081               Specify the ELF symbol visibility for synthesized
1082               "__start_SECNAME" and "__stop_SECNAME" symbols.  value must be
1083               exactly default, internal, hidden, or protected.  If no -z
1084               start-stop-visibility option is given, protected is used for
1085               compatibility with historical practice.  However, it's highly
1086               recommended to use -z start-stop-visibility=hidden in new
1087               programs and shared libraries so that these symbols are not
1088               exported between shared objects, which is not usually what's
1089               intended.
1090
1091           text
1092           notext
1093           textoff
1094               Report an error if DT_TEXTREL is set, i.e., if the position-
1095               independent or shared object has dynamic relocations in read-
1096               only sections.  Don't report an error if notext or textoff.
1097
1098           undefs
1099               Do not report unresolved symbol references from regular object
1100               files, either when creating an executable, or when creating a
1101               shared library.  This option is the inverse of -z defs.
1102
1103           unique-symbol
1104           nounique-symbol
1105               Avoid duplicated local symbol names in the symbol string table.
1106               Append "."number"" to duplicated local symbol names if unique-
1107               symbol is used.  nounique-symbol is the default.
1108
1109           x86-64-baseline
1110           x86-64-v2
1111           x86-64-v3
1112           x86-64-v4
1113               Specify the x86-64 ISA level needed in .note.gnu.property
1114               section.  x86-64-baseline generates
1115               "GNU_PROPERTY_X86_ISA_1_BASELINE".  x86-64-v2 generates
1116               "GNU_PROPERTY_X86_ISA_1_V2".  x86-64-v3 generates
1117               "GNU_PROPERTY_X86_ISA_1_V3".  x86-64-v4 generates
1118               "GNU_PROPERTY_X86_ISA_1_V4".  Supported for Linux/i386 and
1119               Linux/x86_64.
1120
1121           Other keywords are ignored for Solaris compatibility.
1122
1123       -( archives -)
1124       --start-group archives --end-group
1125           The archives should be a list of archive files.  They may be either
1126           explicit file names, or -l options.
1127
1128           The specified archives are searched repeatedly until no new
1129           undefined references are created.  Normally, an archive is searched
1130           only once in the order that it is specified on the command line.
1131           If a symbol in that archive is needed to resolve an undefined
1132           symbol referred to by an object in an archive that appears later on
1133           the command line, the linker would not be able to resolve that
1134           reference.  By grouping the archives, they will all be searched
1135           repeatedly until all possible references are resolved.
1136
1137           Using this option has a significant performance cost.  It is best
1138           to use it only when there are unavoidable circular references
1139           between two or more archives.
1140
1141       --accept-unknown-input-arch
1142       --no-accept-unknown-input-arch
1143           Tells the linker to accept input files whose architecture cannot be
1144           recognised.  The assumption is that the user knows what they are
1145           doing and deliberately wants to link in these unknown input files.
1146           This was the default behaviour of the linker, before release 2.14.
1147           The default behaviour from release 2.14 onwards is to reject such
1148           input files, and so the --accept-unknown-input-arch option has been
1149           added to restore the old behaviour.
1150
1151       --as-needed
1152       --no-as-needed
1153           This option affects ELF DT_NEEDED tags for dynamic libraries
1154           mentioned on the command line after the --as-needed option.
1155           Normally the linker will add a DT_NEEDED tag for each dynamic
1156           library mentioned on the command line, regardless of whether the
1157           library is actually needed or not.  --as-needed causes a DT_NEEDED
1158           tag to only be emitted for a library that at that point in the link
1159           satisfies a non-weak undefined symbol reference from a regular
1160           object file or, if the library is not found in the DT_NEEDED lists
1161           of other needed libraries, a non-weak undefined symbol reference
1162           from another needed dynamic library.  Object files or libraries
1163           appearing on the command line after the library in question do not
1164           affect whether the library is seen as needed.  This is similar to
1165           the rules for extraction of object files from archives.
1166           --no-as-needed restores the default behaviour.
1167
1168           Note: On Linux based systems the --as-needed option also has an
1169           affect on the behaviour of the --rpath and --rpath-link options.
1170           See the description of --rpath-link for more details.
1171
1172       --add-needed
1173       --no-add-needed
1174           These two options have been deprecated because of the similarity of
1175           their names to the --as-needed and --no-as-needed options.  They
1176           have been replaced by --copy-dt-needed-entries and
1177           --no-copy-dt-needed-entries.
1178
1179       -assert keyword
1180           This option is ignored for SunOS compatibility.
1181
1182       -Bdynamic
1183       -dy
1184       -call_shared
1185           Link against dynamic libraries.  This is only meaningful on
1186           platforms for which shared libraries are supported.  This option is
1187           normally the default on such platforms.  The different variants of
1188           this option are for compatibility with various systems.  You may
1189           use this option multiple times on the command line: it affects
1190           library searching for -l options which follow it.
1191
1192       -Bgroup
1193           Set the "DF_1_GROUP" flag in the "DT_FLAGS_1" entry in the dynamic
1194           section.  This causes the runtime linker to handle lookups in this
1195           object and its dependencies to be performed only inside the group.
1196           --unresolved-symbols=report-all is implied.  This option is only
1197           meaningful on ELF platforms which support shared libraries.
1198
1199       -Bstatic
1200       -dn
1201       -non_shared
1202       -static
1203           Do not link against shared libraries.  This is only meaningful on
1204           platforms for which shared libraries are supported.  The different
1205           variants of this option are for compatibility with various systems.
1206           You may use this option multiple times on the command line: it
1207           affects library searching for -l options which follow it.  This
1208           option also implies --unresolved-symbols=report-all.  This option
1209           can be used with -shared.  Doing so means that a shared library is
1210           being created but that all of the library's external references
1211           must be resolved by pulling in entries from static libraries.
1212
1213       -Bsymbolic
1214           When creating a shared library, bind references to global symbols
1215           to the definition within the shared library, if any.  Normally, it
1216           is possible for a program linked against a shared library to
1217           override the definition within the shared library.  This option is
1218           only meaningful on ELF platforms which support shared libraries.
1219
1220       -Bsymbolic-functions
1221           When creating a shared library, bind references to global function
1222           symbols to the definition within the shared library, if any.  This
1223           option is only meaningful on ELF platforms which support shared
1224           libraries.
1225
1226       -Bno-symbolic
1227           This option can cancel previously specified -Bsymbolic and
1228           -Bsymbolic-functions.
1229
1230       --dynamic-list=dynamic-list-file
1231           Specify the name of a dynamic list file to the linker.  This is
1232           typically used when creating shared libraries to specify a list of
1233           global symbols whose references shouldn't be bound to the
1234           definition within the shared library, or creating dynamically
1235           linked executables to specify a list of symbols which should be
1236           added to the symbol table in the executable.  This option is only
1237           meaningful on ELF platforms which support shared libraries.
1238
1239           The format of the dynamic list is the same as the version node
1240           without scope and node name.  See VERSION for more information.
1241
1242       --dynamic-list-data
1243           Include all global data symbols to the dynamic list.
1244
1245       --dynamic-list-cpp-new
1246           Provide the builtin dynamic list for C++ operator new and delete.
1247           It is mainly useful for building shared libstdc++.
1248
1249       --dynamic-list-cpp-typeinfo
1250           Provide the builtin dynamic list for C++ runtime type
1251           identification.
1252
1253       --check-sections
1254       --no-check-sections
1255           Asks the linker not to check section addresses after they have been
1256           assigned to see if there are any overlaps.  Normally the linker
1257           will perform this check, and if it finds any overlaps it will
1258           produce suitable error messages.  The linker does know about, and
1259           does make allowances for sections in overlays.  The default
1260           behaviour can be restored by using the command-line switch
1261           --check-sections.  Section overlap is not usually checked for
1262           relocatable links.  You can force checking in that case by using
1263           the --check-sections option.
1264
1265       --copy-dt-needed-entries
1266       --no-copy-dt-needed-entries
1267           This option affects the treatment of dynamic libraries referred to
1268           by DT_NEEDED tags inside ELF dynamic libraries mentioned on the
1269           command line.  Normally the linker won't add a DT_NEEDED tag to the
1270           output binary for each library mentioned in a DT_NEEDED tag in an
1271           input dynamic library.  With --copy-dt-needed-entries specified on
1272           the command line however any dynamic libraries that follow it will
1273           have their DT_NEEDED entries added.  The default behaviour can be
1274           restored with --no-copy-dt-needed-entries.
1275
1276           This option also has an effect on the resolution of symbols in
1277           dynamic libraries.  With --copy-dt-needed-entries dynamic libraries
1278           mentioned on the command line will be recursively searched,
1279           following their DT_NEEDED tags to other libraries, in order to
1280           resolve symbols required by the output binary.  With the default
1281           setting however the searching of dynamic libraries that follow it
1282           will stop with the dynamic library itself.  No DT_NEEDED links will
1283           be traversed to resolve symbols.
1284
1285       --cref
1286           Output a cross reference table.  If a linker map file is being
1287           generated, the cross reference table is printed to the map file.
1288           Otherwise, it is printed on the standard output.
1289
1290           The format of the table is intentionally simple, so that it may be
1291           easily processed by a script if necessary.  The symbols are printed
1292           out, sorted by name.  For each symbol, a list of file names is
1293           given.  If the symbol is defined, the first file listed is the
1294           location of the definition.  If the symbol is defined as a common
1295           value then any files where this happens appear next.  Finally any
1296           files that reference the symbol are listed.
1297
1298       --ctf-variables
1299       --no-ctf-variables
1300           The CTF debuginfo format supports a section which encodes the names
1301           and types of variables found in the program which do not appear in
1302           any symbol table. These variables clearly cannot be looked up by
1303           address by conventional debuggers, so the space used for their
1304           types and names is usually wasted: the types are usually small but
1305           the names are often not.  --ctf-variables causes the generation of
1306           such a section.  The default behaviour can be restored with
1307           --no-ctf-variables.
1308
1309       --ctf-share-types=method
1310           Adjust the method used to share types between translation units in
1311           CTF.
1312
1313           share-unconflicted
1314               Put all types that do not have ambiguous definitions into the
1315               shared dictionary, where debuggers can easily access them, even
1316               if they only occur in one translation unit.  This is the
1317               default.
1318
1319           share-duplicated
1320               Put only types that occur in multiple translation units into
1321               the shared dictionary: types with only one definition go into
1322               per-translation-unit dictionaries.  Types with ambiguous
1323               definitions in multiple translation units always go into per-
1324               translation-unit dictionaries.  This tends to make the CTF
1325               larger, but may reduce the amount of CTF in the shared
1326               dictionary.  For very large projects this may speed up opening
1327               the CTF and save memory in the CTF consumer at runtime.
1328
1329       --no-define-common
1330           This option inhibits the assignment of addresses to common symbols.
1331           The script command "INHIBIT_COMMON_ALLOCATION" has the same effect.
1332
1333           The --no-define-common option allows decoupling the decision to
1334           assign addresses to Common symbols from the choice of the output
1335           file type; otherwise a non-Relocatable output type forces assigning
1336           addresses to Common symbols.  Using --no-define-common allows
1337           Common symbols that are referenced from a shared library to be
1338           assigned addresses only in the main program.  This eliminates the
1339           unused duplicate space in the shared library, and also prevents any
1340           possible confusion over resolving to the wrong duplicate when there
1341           are many dynamic modules with specialized search paths for runtime
1342           symbol resolution.
1343
1344       --force-group-allocation
1345           This option causes the linker to place section group members like
1346           normal input sections, and to delete the section groups.  This is
1347           the default behaviour for a final link but this option can be used
1348           to change the behaviour of a relocatable link (-r).  The script
1349           command "FORCE_GROUP_ALLOCATION" has the same effect.
1350
1351       --defsym=symbol=expression
1352           Create a global symbol in the output file, containing the absolute
1353           address given by expression.  You may use this option as many times
1354           as necessary to define multiple symbols in the command line.  A
1355           limited form of arithmetic is supported for the expression in this
1356           context: you may give a hexadecimal constant or the name of an
1357           existing symbol, or use "+" and "-" to add or subtract hexadecimal
1358           constants or symbols.  If you need more elaborate expressions,
1359           consider using the linker command language from a script.  Note:
1360           there should be no white space between symbol, the equals sign
1361           ("="), and expression.
1362
1363           The linker processes --defsym arguments and -T arguments in order,
1364           placing --defsym before -T will define the symbol before the linker
1365           script from -T is processed, while placing --defsym after -T will
1366           define the symbol after the linker script has been processed.  This
1367           difference has consequences for expressions within the linker
1368           script that use the --defsym symbols, which order is correct will
1369           depend on what you are trying to achieve.
1370
1371       --demangle[=style]
1372       --no-demangle
1373           These options control whether to demangle symbol names in error
1374           messages and other output.  When the linker is told to demangle, it
1375           tries to present symbol names in a readable fashion: it strips
1376           leading underscores if they are used by the object file format, and
1377           converts C++ mangled symbol names into user readable names.
1378           Different compilers have different mangling styles.  The optional
1379           demangling style argument can be used to choose an appropriate
1380           demangling style for your compiler.  The linker will demangle by
1381           default unless the environment variable COLLECT_NO_DEMANGLE is set.
1382           These options may be used to override the default.
1383
1384       -Ifile
1385       --dynamic-linker=file
1386           Set the name of the dynamic linker.  This is only meaningful when
1387           generating dynamically linked ELF executables.  The default dynamic
1388           linker is normally correct; don't use this unless you know what you
1389           are doing.
1390
1391       --no-dynamic-linker
1392           When producing an executable file, omit the request for a dynamic
1393           linker to be used at load-time.  This is only meaningful for ELF
1394           executables that contain dynamic relocations, and usually requires
1395           entry point code that is capable of processing these relocations.
1396
1397       --embedded-relocs
1398           This option is similar to the --emit-relocs option except that the
1399           relocs are stored in a target-specific section.  This option is
1400           only supported by the BFIN, CR16 and M68K targets.
1401
1402       --disable-multiple-abs-defs
1403           Do not allow multiple definitions with symbols included in filename
1404           invoked by -R or --just-symbols
1405
1406       --fatal-warnings
1407       --no-fatal-warnings
1408           Treat all warnings as errors.  The default behaviour can be
1409           restored with the option --no-fatal-warnings.
1410
1411       -w
1412       --no-warnings
1413           Do not display any warning or error messages.  This overrides
1414           --fatal-warnings if it has been enabled.  This option can be used
1415           when it is known that the output binary will not work, but there is
1416           still a need to create it.
1417
1418       --force-exe-suffix
1419           Make sure that an output file has a .exe suffix.
1420
1421           If a successfully built fully linked output file does not have a
1422           ".exe" or ".dll" suffix, this option forces the linker to copy the
1423           output file to one of the same name with a ".exe" suffix. This
1424           option is useful when using unmodified Unix makefiles on a
1425           Microsoft Windows host, since some versions of Windows won't run an
1426           image unless it ends in a ".exe" suffix.
1427
1428       --gc-sections
1429       --no-gc-sections
1430           Enable garbage collection of unused input sections.  It is ignored
1431           on targets that do not support this option.  The default behaviour
1432           (of not performing this garbage collection) can be restored by
1433           specifying --no-gc-sections on the command line.  Note that garbage
1434           collection for COFF and PE format targets is supported, but the
1435           implementation is currently considered to be experimental.
1436
1437           --gc-sections decides which input sections are used by examining
1438           symbols and relocations.  The section containing the entry symbol
1439           and all sections containing symbols undefined on the command-line
1440           will be kept, as will sections containing symbols referenced by
1441           dynamic objects.  Note that when building shared libraries, the
1442           linker must assume that any visible symbol is referenced.  Once
1443           this initial set of sections has been determined, the linker
1444           recursively marks as used any section referenced by their
1445           relocations.  See --entry, --undefined, and --gc-keep-exported.
1446
1447           This option can be set when doing a partial link (enabled with
1448           option -r).  In this case the root of symbols kept must be
1449           explicitly specified either by one of the options --entry,
1450           --undefined, or --gc-keep-exported or by a "ENTRY" command in the
1451           linker script.
1452
1453           As a GNU extension, ELF input sections marked with the
1454           "SHF_GNU_RETAIN" flag will not be garbage collected.
1455
1456       --print-gc-sections
1457       --no-print-gc-sections
1458           List all sections removed by garbage collection.  The listing is
1459           printed on stderr.  This option is only effective if garbage
1460           collection has been enabled via the --gc-sections) option.  The
1461           default behaviour (of not listing the sections that are removed)
1462           can be restored by specifying --no-print-gc-sections on the command
1463           line.
1464
1465       --gc-keep-exported
1466           When --gc-sections is enabled, this option prevents garbage
1467           collection of unused input sections that contain global symbols
1468           having default or protected visibility.  This option is intended to
1469           be used for executables where unreferenced sections would otherwise
1470           be garbage collected regardless of the external visibility of
1471           contained symbols.  Note that this option has no effect when
1472           linking shared objects since it is already the default behaviour.
1473           This option is only supported for ELF format targets.
1474
1475       --print-output-format
1476           Print the name of the default output format (perhaps influenced by
1477           other command-line options).  This is the string that would appear
1478           in an "OUTPUT_FORMAT" linker script command.
1479
1480       --print-memory-usage
1481           Print used size, total size and used size of memory regions created
1482           with the MEMORY command.  This is useful on embedded targets to
1483           have a quick view of amount of free memory.  The format of the
1484           output has one headline and one line per region.  It is both human
1485           readable and easily parsable by tools.  Here is an example of an
1486           output:
1487
1488                   Memory region         Used Size  Region Size  %age Used
1489                                ROM:        256 KB         1 MB     25.00%
1490                                RAM:          32 B         2 GB      0.00%
1491
1492       --help
1493           Print a summary of the command-line options on the standard output
1494           and exit.
1495
1496       --target-help
1497           Print a summary of all target-specific options on the standard
1498           output and exit.
1499
1500       -Map=mapfile
1501           Print a link map to the file mapfile.  See the description of the
1502           -M option, above.  If mapfile is just the character "-" then the
1503           map will be written to stdout.
1504
1505           Specifying a directory as mapfile causes the linker map to be
1506           written as a file inside the directory.  Normally name of the file
1507           inside the directory is computed as the basename of the output file
1508           with ".map" appended.   If however the special character "%" is
1509           used then this will be replaced by the full path of the output
1510           file.  Additionally if there are any characters after the % symbol
1511           then ".map" will no longer be appended.
1512
1513                    -o foo.exe -Map=bar                  [Creates ./bar]
1514                    -o ../dir/foo.exe -Map=bar           [Creates ./bar]
1515                    -o foo.exe -Map=../dir               [Creates ../dir/foo.exe.map]
1516                    -o ../dir2/foo.exe -Map=../dir       [Creates ../dir/foo.exe.map]
1517                    -o foo.exe -Map=%                    [Creates ./foo.exe.map]
1518                    -o ../dir/foo.exe -Map=%             [Creates ../dir/foo.exe.map]
1519                    -o foo.exe -Map=%.bar                [Creates ./foo.exe.bar]
1520                    -o ../dir/foo.exe -Map=%.bar         [Creates ../dir/foo.exe.bar]
1521                    -o ../dir2/foo.exe -Map=../dir/%     [Creates ../dir/../dir2/foo.exe.map]
1522                    -o ../dir2/foo.exe -Map=../dir/%.bar [Creates ../dir/../dir2/foo.exe.bar]
1523
1524           It is an error to specify more than one "%" character.
1525
1526           If the map file already exists then it will be overwritten by this
1527           operation.
1528
1529       --no-keep-memory
1530           ld normally optimizes for speed over memory usage by caching the
1531           symbol tables of input files in memory.  This option tells ld to
1532           instead optimize for memory usage, by rereading the symbol tables
1533           as necessary.  This may be required if ld runs out of memory space
1534           while linking a large executable.
1535
1536       --no-undefined
1537       -z defs
1538           Report unresolved symbol references from regular object files.
1539           This is done even if the linker is creating a non-symbolic shared
1540           library.  The switch --[no-]allow-shlib-undefined controls the
1541           behaviour for reporting unresolved references found in shared
1542           libraries being linked in.
1543
1544           The effects of this option can be reverted by using "-z undefs".
1545
1546       --allow-multiple-definition
1547       -z muldefs
1548           Normally when a symbol is defined multiple times, the linker will
1549           report a fatal error. These options allow multiple definitions and
1550           the first definition will be used.
1551
1552       --allow-shlib-undefined
1553       --no-allow-shlib-undefined
1554           Allows or disallows undefined symbols in shared libraries.  This
1555           switch is similar to --no-undefined except that it determines the
1556           behaviour when the undefined symbols are in a shared library rather
1557           than a regular object file.  It does not affect how undefined
1558           symbols in regular object files are handled.
1559
1560           The default behaviour is to report errors for any undefined symbols
1561           referenced in shared libraries if the linker is being used to
1562           create an executable, but to allow them if the linker is being used
1563           to create a shared library.
1564
1565           The reasons for allowing undefined symbol references in shared
1566           libraries specified at link time are that:
1567
1568           •   A shared library specified at link time may not be the same as
1569               the one that is available at load time, so the symbol might
1570               actually be resolvable at load time.
1571
1572           •   There are some operating systems, eg BeOS and HPPA, where
1573               undefined symbols in shared libraries are normal.
1574
1575               The BeOS kernel for example patches shared libraries at load
1576               time to select whichever function is most appropriate for the
1577               current architecture.  This is used, for example, to
1578               dynamically select an appropriate memset function.
1579
1580       --error-handling-script=scriptname
1581           If this option is provided then the linker will invoke scriptname
1582           whenever an error is encountered.  Currently however only two kinds
1583           of error are supported: missing symbols and missing libraries.  Two
1584           arguments will be passed to script: the keyword "undefined-symbol"
1585           or `missing-lib" and the name of the undefined symbol or missing
1586           library.  The intention is that the script will provide suggestions
1587           to the user as to where the symbol or library might be found.
1588           After the script has finished then the normal linker error message
1589           will be displayed.
1590
1591           The availability of this option is controlled by a configure time
1592           switch, so it may not be present in specific implementations.
1593
1594       --no-undefined-version
1595           Normally when a symbol has an undefined version, the linker will
1596           ignore it. This option disallows symbols with undefined version and
1597           a fatal error will be issued instead.
1598
1599       --default-symver
1600           Create and use a default symbol version (the soname) for
1601           unversioned exported symbols.
1602
1603       --default-imported-symver
1604           Create and use a default symbol version (the soname) for
1605           unversioned imported symbols.
1606
1607       --no-warn-mismatch
1608           Normally ld will give an error if you try to link together input
1609           files that are mismatched for some reason, perhaps because they
1610           have been compiled for different processors or for different
1611           endiannesses.  This option tells ld that it should silently permit
1612           such possible errors.  This option should only be used with care,
1613           in cases when you have taken some special action that ensures that
1614           the linker errors are inappropriate.
1615
1616       --no-warn-search-mismatch
1617           Normally ld will give a warning if it finds an incompatible library
1618           during a library search.  This option silences the warning.
1619
1620       --no-whole-archive
1621           Turn off the effect of the --whole-archive option for subsequent
1622           archive files.
1623
1624       --noinhibit-exec
1625           Retain the executable output file whenever it is still usable.
1626           Normally, the linker will not produce an output file if it
1627           encounters errors during the link process; it exits without writing
1628           an output file when it issues any error whatsoever.
1629
1630       -nostdlib
1631           Only search library directories explicitly specified on the command
1632           line.  Library directories specified in linker scripts (including
1633           linker scripts specified on the command line) are ignored.
1634
1635       --oformat=output-format
1636           ld may be configured to support more than one kind of object file.
1637           If your ld is configured this way, you can use the --oformat option
1638           to specify the binary format for the output object file.  Even when
1639           ld is configured to support alternative object formats, you don't
1640           usually need to specify this, as ld should be configured to produce
1641           as a default output format the most usual format on each machine.
1642           output-format is a text string, the name of a particular format
1643           supported by the BFD libraries.  (You can list the available binary
1644           formats with objdump -i.)  The script command "OUTPUT_FORMAT" can
1645           also specify the output format, but this option overrides it.
1646
1647       --out-implib file
1648           Create an import library in file corresponding to the executable
1649           the linker is generating (eg. a DLL or ELF program).  This import
1650           library (which should be called "*.dll.a" or "*.a" for DLLs) may be
1651           used to link clients against the generated executable; this
1652           behaviour makes it possible to skip a separate import library
1653           creation step (eg. "dlltool" for DLLs).  This option is only
1654           available for the i386 PE and ELF targetted ports of the linker.
1655
1656       -pie
1657       --pic-executable
1658           Create a position independent executable.  This is currently only
1659           supported on ELF platforms.  Position independent executables are
1660           similar to shared libraries in that they are relocated by the
1661           dynamic linker to the virtual address the OS chooses for them
1662           (which can vary between invocations).  Like normal dynamically
1663           linked executables they can be executed and symbols defined in the
1664           executable cannot be overridden by shared libraries.
1665
1666       -no-pie
1667           Create a position dependent executable.  This is the default.
1668
1669       -qmagic
1670           This option is ignored for Linux compatibility.
1671
1672       -Qy This option is ignored for SVR4 compatibility.
1673
1674       --relax
1675       --no-relax
1676           An option with machine dependent effects.  This option is only
1677           supported on a few targets.
1678
1679           On some platforms the --relax option performs target specific,
1680           global optimizations that become possible when the linker resolves
1681           addressing in the program, such as relaxing address modes,
1682           synthesizing new instructions, selecting shorter version of current
1683           instructions, and combining constant values.
1684
1685           On some platforms these link time global optimizations may make
1686           symbolic debugging of the resulting executable impossible.  This is
1687           known to be the case for the Matsushita MN10200 and MN10300 family
1688           of processors.
1689
1690           On platforms where the feature is supported, the option --no-relax
1691           will disable it.
1692
1693           On platforms where the feature is not supported, both --relax and
1694           --no-relax are accepted, but ignored.
1695
1696       --retain-symbols-file=filename
1697           Retain only the symbols listed in the file filename, discarding all
1698           others.  filename is simply a flat file, with one symbol name per
1699           line.  This option is especially useful in environments (such as
1700           VxWorks) where a large global symbol table is accumulated
1701           gradually, to conserve run-time memory.
1702
1703           --retain-symbols-file does not discard undefined symbols, or
1704           symbols needed for relocations.
1705
1706           You may only specify --retain-symbols-file once in the command
1707           line.  It overrides -s and -S.
1708
1709       -rpath=dir
1710           Add a directory to the runtime library search path.  This is used
1711           when linking an ELF executable with shared objects.  All -rpath
1712           arguments are concatenated and passed to the runtime linker, which
1713           uses them to locate shared objects at runtime.
1714
1715           The -rpath option is also used when locating shared objects which
1716           are needed by shared objects explicitly included in the link; see
1717           the description of the -rpath-link option.  Searching -rpath in
1718           this way is only supported by native linkers and cross linkers
1719           which have been configured with the --with-sysroot option.
1720
1721           If -rpath is not used when linking an ELF executable, the contents
1722           of the environment variable "LD_RUN_PATH" will be used if it is
1723           defined.
1724
1725           The -rpath option may also be used on SunOS.  By default, on SunOS,
1726           the linker will form a runtime search path out of all the -L
1727           options it is given.  If a -rpath option is used, the runtime
1728           search path will be formed exclusively using the -rpath options,
1729           ignoring the -L options.  This can be useful when using gcc, which
1730           adds many -L options which may be on NFS mounted file systems.
1731
1732           For compatibility with other ELF linkers, if the -R option is
1733           followed by a directory name, rather than a file name, it is
1734           treated as the -rpath option.
1735
1736       -rpath-link=dir
1737           When using ELF or SunOS, one shared library may require another.
1738           This happens when an "ld -shared" link includes a shared library as
1739           one of the input files.
1740
1741           When the linker encounters such a dependency when doing a non-
1742           shared, non-relocatable link, it will automatically try to locate
1743           the required shared library and include it in the link, if it is
1744           not included explicitly.  In such a case, the -rpath-link option
1745           specifies the first set of directories to search.  The -rpath-link
1746           option may specify a sequence of directory names either by
1747           specifying a list of names separated by colons, or by appearing
1748           multiple times.
1749
1750           The tokens $ORIGIN and $LIB can appear in these search directories.
1751           They will be replaced by the full path to the directory containing
1752           the program or shared object in the case of $ORIGIN and either lib
1753           - for 32-bit binaries - or lib64 - for 64-bit binaries - in the
1754           case of $LIB.
1755
1756           The alternative form of these tokens - ${ORIGIN} and ${LIB} can
1757           also be used.  The token $PLATFORM is not supported.
1758
1759           This option should be used with caution as it overrides the search
1760           path that may have been hard compiled into a shared library. In
1761           such a case it is possible to use unintentionally a different
1762           search path than the runtime linker would do.
1763
1764           The linker uses the following search paths to locate required
1765           shared libraries:
1766
1767           1.  Any directories specified by -rpath-link options.
1768
1769           2.  Any directories specified by -rpath options.  The difference
1770               between -rpath and -rpath-link is that directories specified by
1771               -rpath options are included in the executable and used at
1772               runtime, whereas the -rpath-link option is only effective at
1773               link time. Searching -rpath in this way is only supported by
1774               native linkers and cross linkers which have been configured
1775               with the --with-sysroot option.
1776
1777           3.  On an ELF system, for native linkers, if the -rpath and
1778               -rpath-link options were not used, search the contents of the
1779               environment variable "LD_RUN_PATH".
1780
1781           4.  On SunOS, if the -rpath option was not used, search any
1782               directories specified using -L options.
1783
1784           5.  For a native linker, search the contents of the environment
1785               variable "LD_LIBRARY_PATH".
1786
1787           6.  For a native ELF linker, the directories in "DT_RUNPATH" or
1788               "DT_RPATH" of a shared library are searched for shared
1789               libraries needed by it. The "DT_RPATH" entries are ignored if
1790               "DT_RUNPATH" entries exist.
1791
1792           7.  For a linker for a Linux system, if the file /etc/ld.so.conf
1793               exists, the list of directories found in that file.  Note: the
1794               path to this file is prefixed with the "sysroot" value, if that
1795               is defined, and then any "prefix" string if the linker was
1796               configured with the --prefix=<path> option.
1797
1798           8.  For a native linker on a FreeBSD system, any directories
1799               specified by the "_PATH_ELF_HINTS" macro defined in the
1800               elf-hints.h header file.
1801
1802           9.  Any directories specified by a "SEARCH_DIR" command in a linker
1803               script given on the command line, including scripts specified
1804               by -T (but not -dT).
1805
1806           10. The default directories, normally /lib and /usr/lib.
1807
1808           11. Any directories specified by a plugin
1809               LDPT_SET_EXTRA_LIBRARY_PATH.
1810
1811           12. Any directories specified by a "SEARCH_DIR" command in a
1812               default linker script.
1813
1814           Note however on Linux based systems there is an additional caveat:
1815           If the --as-needed option is active and a shared library is located
1816           which would normally satisfy the search and this library does not
1817           have DT_NEEDED tag for libc.so and there is a shared library later
1818           on in the set of search directories which also satisfies the search
1819           and this second shared library does have a DT_NEEDED tag for
1820           libc.so then the second library will be selected instead of the
1821           first.
1822
1823           If the required shared library is not found, the linker will issue
1824           a warning and continue with the link.
1825
1826       -shared
1827       -Bshareable
1828           Create a shared library.  This is currently only supported on ELF,
1829           XCOFF and SunOS platforms.  On SunOS, the linker will automatically
1830           create a shared library if the -e option is not used and there are
1831           undefined symbols in the link.
1832
1833       --sort-common
1834       --sort-common=ascending
1835       --sort-common=descending
1836           This option tells ld to sort the common symbols by alignment in
1837           ascending or descending order when it places them in the
1838           appropriate output sections.  The symbol alignments considered are
1839           sixteen-byte or larger, eight-byte, four-byte, two-byte, and one-
1840           byte. This is to prevent gaps between symbols due to alignment
1841           constraints.  If no sorting order is specified, then descending
1842           order is assumed.
1843
1844       --sort-section=name
1845           This option will apply "SORT_BY_NAME" to all wildcard section
1846           patterns in the linker script.
1847
1848       --sort-section=alignment
1849           This option will apply "SORT_BY_ALIGNMENT" to all wildcard section
1850           patterns in the linker script.
1851
1852       --spare-dynamic-tags=count
1853           This option specifies the number of empty slots to leave in the
1854           .dynamic section of ELF shared objects.  Empty slots may be needed
1855           by post processing tools, such as the prelinker.  The default is 5.
1856
1857       --split-by-file[=size]
1858           Similar to --split-by-reloc but creates a new output section for
1859           each input file when size is reached.  size defaults to a size of 1
1860           if not given.
1861
1862       --split-by-reloc[=count]
1863           Tries to creates extra sections in the output file so that no
1864           single output section in the file contains more than count
1865           relocations.  This is useful when generating huge relocatable files
1866           for downloading into certain real time kernels with the COFF object
1867           file format; since COFF cannot represent more than 65535
1868           relocations in a single section.  Note that this will fail to work
1869           with object file formats which do not support arbitrary sections.
1870           The linker will not split up individual input sections for
1871           redistribution, so if a single input section contains more than
1872           count relocations one output section will contain that many
1873           relocations.  count defaults to a value of 32768.
1874
1875       --stats
1876           Compute and display statistics about the operation of the linker,
1877           such as execution time and memory usage.
1878
1879       --sysroot=directory
1880           Use directory as the location of the sysroot, overriding the
1881           configure-time default.  This option is only supported by linkers
1882           that were configured using --with-sysroot.
1883
1884       --task-link
1885           This is used by COFF/PE based targets to create a task-linked
1886           object file where all of the global symbols have been converted to
1887           statics.
1888
1889       --traditional-format
1890           For some targets, the output of ld is different in some ways from
1891           the output of some existing linker.  This switch requests ld to use
1892           the traditional format instead.
1893
1894           For example, on SunOS, ld combines duplicate entries in the symbol
1895           string table.  This can reduce the size of an output file with full
1896           debugging information by over 30 percent.  Unfortunately, the SunOS
1897           "dbx" program can not read the resulting program ("gdb" has no
1898           trouble).  The --traditional-format switch tells ld to not combine
1899           duplicate entries.
1900
1901       --section-start=sectionname=org
1902           Locate a section in the output file at the absolute address given
1903           by org.  You may use this option as many times as necessary to
1904           locate multiple sections in the command line.  org must be a single
1905           hexadecimal integer; for compatibility with other linkers, you may
1906           omit the leading 0x usually associated with hexadecimal values.
1907           Note: there should be no white space between sectionname, the
1908           equals sign ("="), and org.
1909
1910       -Tbss=org
1911       -Tdata=org
1912       -Ttext=org
1913           Same as --section-start, with ".bss", ".data" or ".text" as the
1914           sectionname.
1915
1916       -Ttext-segment=org
1917           When creating an ELF executable, it will set the address of the
1918           first byte of the text segment.
1919
1920       -Trodata-segment=org
1921           When creating an ELF executable or shared object for a target where
1922           the read-only data is in its own segment separate from the
1923           executable text, it will set the address of the first byte of the
1924           read-only data segment.
1925
1926       -Tldata-segment=org
1927           When creating an ELF executable or shared object for x86-64 medium
1928           memory model, it will set the address of the first byte of the
1929           ldata segment.
1930
1931       --unresolved-symbols=method
1932           Determine how to handle unresolved symbols.  There are four
1933           possible values for method:
1934
1935           ignore-all
1936               Do not report any unresolved symbols.
1937
1938           report-all
1939               Report all unresolved symbols.  This is the default.
1940
1941           ignore-in-object-files
1942               Report unresolved symbols that are contained in shared
1943               libraries, but ignore them if they come from regular object
1944               files.
1945
1946           ignore-in-shared-libs
1947               Report unresolved symbols that come from regular object files,
1948               but ignore them if they come from shared libraries.  This can
1949               be useful when creating a dynamic binary and it is known that
1950               all the shared libraries that it should be referencing are
1951               included on the linker's command line.
1952
1953           The behaviour for shared libraries on their own can also be
1954           controlled by the --[no-]allow-shlib-undefined option.
1955
1956           Normally the linker will generate an error message for each
1957           reported unresolved symbol but the option --warn-unresolved-symbols
1958           can change this to a warning.
1959
1960       --dll-verbose
1961       --verbose[=NUMBER]
1962           Display the version number for ld and list the linker emulations
1963           supported.  Display which input files can and cannot be opened.
1964           Display the linker script being used by the linker. If the optional
1965           NUMBER argument > 1, plugin symbol status will also be displayed.
1966
1967       --version-script=version-scriptfile
1968           Specify the name of a version script to the linker.  This is
1969           typically used when creating shared libraries to specify additional
1970           information about the version hierarchy for the library being
1971           created.  This option is only fully supported on ELF platforms
1972           which support shared libraries; see VERSION.  It is partially
1973           supported on PE platforms, which can use version scripts to filter
1974           symbol visibility in auto-export mode: any symbols marked local in
1975           the version script will not be exported.
1976
1977       --warn-common
1978           Warn when a common symbol is combined with another common symbol or
1979           with a symbol definition.  Unix linkers allow this somewhat sloppy
1980           practice, but linkers on some other operating systems do not.  This
1981           option allows you to find potential problems from combining global
1982           symbols.  Unfortunately, some C libraries use this practice, so you
1983           may get some warnings about symbols in the libraries as well as in
1984           your programs.
1985
1986           There are three kinds of global symbols, illustrated here by C
1987           examples:
1988
1989           int i = 1;
1990               A definition, which goes in the initialized data section of the
1991               output file.
1992
1993           extern int i;
1994               An undefined reference, which does not allocate space.  There
1995               must be either a definition or a common symbol for the variable
1996               somewhere.
1997
1998           int i;
1999               A common symbol.  If there are only (one or more) common
2000               symbols for a variable, it goes in the uninitialized data area
2001               of the output file.  The linker merges multiple common symbols
2002               for the same variable into a single symbol.  If they are of
2003               different sizes, it picks the largest size.  The linker turns a
2004               common symbol into a declaration, if there is a definition of
2005               the same variable.
2006
2007           The --warn-common option can produce five kinds of warnings.  Each
2008           warning consists of a pair of lines: the first describes the symbol
2009           just encountered, and the second describes the previous symbol
2010           encountered with the same name.  One or both of the two symbols
2011           will be a common symbol.
2012
2013           1.  Turning a common symbol into a reference, because there is
2014               already a definition for the symbol.
2015
2016                       <file>(<section>): warning: common of `<symbol>'
2017                          overridden by definition
2018                       <file>(<section>): warning: defined here
2019
2020           2.  Turning a common symbol into a reference, because a later
2021               definition for the symbol is encountered.  This is the same as
2022               the previous case, except that the symbols are encountered in a
2023               different order.
2024
2025                       <file>(<section>): warning: definition of `<symbol>'
2026                          overriding common
2027                       <file>(<section>): warning: common is here
2028
2029           3.  Merging a common symbol with a previous same-sized common
2030               symbol.
2031
2032                       <file>(<section>): warning: multiple common
2033                          of `<symbol>'
2034                       <file>(<section>): warning: previous common is here
2035
2036           4.  Merging a common symbol with a previous larger common symbol.
2037
2038                       <file>(<section>): warning: common of `<symbol>'
2039                          overridden by larger common
2040                       <file>(<section>): warning: larger common is here
2041
2042           5.  Merging a common symbol with a previous smaller common symbol.
2043               This is the same as the previous case, except that the symbols
2044               are encountered in a different order.
2045
2046                       <file>(<section>): warning: common of `<symbol>'
2047                          overriding smaller common
2048                       <file>(<section>): warning: smaller common is here
2049
2050       --warn-constructors
2051           Warn if any global constructors are used.  This is only useful for
2052           a few object file formats.  For formats like COFF or ELF, the
2053           linker can not detect the use of global constructors.
2054
2055       --warn-execstack
2056       --no-warn-execstack
2057           On ELF platforms this option controls how the linker generates
2058           warning messages when it creates an output file with an executable
2059           stack.  By default the linker will not warn if the -z execstack
2060           command line option has been used, but this behaviour can be
2061           overridden by the --warn-execstack option.
2062
2063           On the other hand the linker will normally warn if the stack is
2064           made executable because one or more of the input files need an
2065           execuable stack and neither of the -z execstack or -z noexecstack
2066           command line options have been specified.  This warning can be
2067           disabled via the --no-warn-execstack option.
2068
2069           Note: ELF format input files specify that they need an executable
2070           stack by having a .note.GNU-stack section with the executable bit
2071           set in its section flags.  They can specify that they do not need
2072           an executable stack by having that section, but without the
2073           executable flag bit set.  If an input file does not have a
2074           .note.GNU-stack section present then the default behaviour is
2075           target specific.  For some targets, then absence of such a section
2076           implies that an executable stack is required.  This is often a
2077           problem for hand crafted assembler files.
2078
2079       --warn-multiple-gp
2080           Warn if multiple global pointer values are required in the output
2081           file.  This is only meaningful for certain processors, such as the
2082           Alpha.  Specifically, some processors put large-valued constants in
2083           a special section.  A special register (the global pointer) points
2084           into the middle of this section, so that constants can be loaded
2085           efficiently via a base-register relative addressing mode.  Since
2086           the offset in base-register relative mode is fixed and relatively
2087           small (e.g., 16 bits), this limits the maximum size of the constant
2088           pool.  Thus, in large programs, it is often necessary to use
2089           multiple global pointer values in order to be able to address all
2090           possible constants.  This option causes a warning to be issued
2091           whenever this case occurs.
2092
2093       --warn-once
2094           Only warn once for each undefined symbol, rather than once per
2095           module which refers to it.
2096
2097       --warn-rwx-segments
2098       --no-warn-rwx-segments
2099           Warn if the linker creates a loadable, non-zero sized segment that
2100           has all three of the read, write and execute permission flags set.
2101           Such a segment represents a potential security vulnerability.  In
2102           addition warnings will be generated if a thread local storage
2103           segment is created with the execute permission flag set, regardless
2104           of whether or not it has the read and/or write flags set.
2105
2106           These warnings are enabled by default.  They can be disabled via
2107           the --no-warn-rwx-segments option and re-enabled via the
2108           --warn-rwx-segments option.
2109
2110       --warn-section-align
2111           Warn if the address of an output section is changed because of
2112           alignment.  Typically, the alignment will be set by an input
2113           section.  The address will only be changed if it not explicitly
2114           specified; that is, if the "SECTIONS" command does not specify a
2115           start address for the section.
2116
2117       --warn-textrel
2118           Warn if the linker adds DT_TEXTREL to a position-independent
2119           executable or shared object.
2120
2121       --warn-alternate-em
2122           Warn if an object has alternate ELF machine code.
2123
2124       --warn-unresolved-symbols
2125           If the linker is going to report an unresolved symbol (see the
2126           option --unresolved-symbols) it will normally generate an error.
2127           This option makes it generate a warning instead.
2128
2129       --error-unresolved-symbols
2130           This restores the linker's default behaviour of generating errors
2131           when it is reporting unresolved symbols.
2132
2133       --whole-archive
2134           For each archive mentioned on the command line after the
2135           --whole-archive option, include every object file in the archive in
2136           the link, rather than searching the archive for the required object
2137           files.  This is normally used to turn an archive file into a shared
2138           library, forcing every object to be included in the resulting
2139           shared library.  This option may be used more than once.
2140
2141           Two notes when using this option from gcc: First, gcc doesn't know
2142           about this option, so you have to use -Wl,-whole-archive.  Second,
2143           don't forget to use -Wl,-no-whole-archive after your list of
2144           archives, because gcc will add its own list of archives to your
2145           link and you may not want this flag to affect those as well.
2146
2147       --wrap=symbol
2148           Use a wrapper function for symbol.  Any undefined reference to
2149           symbol will be resolved to "__wrap_symbol".  Any undefined
2150           reference to "__real_symbol" will be resolved to symbol.
2151
2152           This can be used to provide a wrapper for a system function.  The
2153           wrapper function should be called "__wrap_symbol".  If it wishes to
2154           call the system function, it should call "__real_symbol".
2155
2156           Here is a trivial example:
2157
2158                   void *
2159                   __wrap_malloc (size_t c)
2160                   {
2161                     printf ("malloc called with %zu\n", c);
2162                     return __real_malloc (c);
2163                   }
2164
2165           If you link other code with this file using --wrap malloc, then all
2166           calls to "malloc" will call the function "__wrap_malloc" instead.
2167           The call to "__real_malloc" in "__wrap_malloc" will call the real
2168           "malloc" function.
2169
2170           You may wish to provide a "__real_malloc" function as well, so that
2171           links without the --wrap option will succeed.  If you do this, you
2172           should not put the definition of "__real_malloc" in the same file
2173           as "__wrap_malloc"; if you do, the assembler may resolve the call
2174           before the linker has a chance to wrap it to "malloc".
2175
2176           Only undefined references are replaced by the linker.  So,
2177           translation unit internal references to symbol are not resolved to
2178           "__wrap_symbol".  In the next example, the call to "f" in "g" is
2179           not resolved to "__wrap_f".
2180
2181                   int
2182                   f (void)
2183                   {
2184                     return 123;
2185                   }
2186
2187                   int
2188                   g (void)
2189                   {
2190                     return f();
2191                   }
2192
2193       --eh-frame-hdr
2194       --no-eh-frame-hdr
2195           Request (--eh-frame-hdr) or suppress (--no-eh-frame-hdr) the
2196           creation of ".eh_frame_hdr" section and ELF "PT_GNU_EH_FRAME"
2197           segment header.
2198
2199       --no-ld-generated-unwind-info
2200           Request creation of ".eh_frame" unwind info for linker generated
2201           code sections like PLT.  This option is on by default if linker
2202           generated unwind info is supported.  This option also controls the
2203           generation of ".sframe" unwind info for linker generated code
2204           sections like PLT.
2205
2206       --enable-new-dtags
2207       --disable-new-dtags
2208           This linker can create the new dynamic tags in ELF. But the older
2209           ELF systems may not understand them. If you specify
2210           --enable-new-dtags, the new dynamic tags will be created as needed
2211           and older dynamic tags will be omitted.  If you specify
2212           --disable-new-dtags, no new dynamic tags will be created. By
2213           default, the new dynamic tags are not created. Note that those
2214           options are only available for ELF systems.
2215
2216       --hash-size=number
2217           Set the default size of the linker's hash tables to a prime number
2218           close to number.  Increasing this value can reduce the length of
2219           time it takes the linker to perform its tasks, at the expense of
2220           increasing the linker's memory requirements.  Similarly reducing
2221           this value can reduce the memory requirements at the expense of
2222           speed.
2223
2224       --hash-style=style
2225           Set the type of linker's hash table(s).  style can be either "sysv"
2226           for classic ELF ".hash" section, "gnu" for new style GNU
2227           ".gnu.hash" section or "both" for both the classic ELF ".hash" and
2228           new style GNU ".gnu.hash" hash tables.  The default depends upon
2229           how the linker was configured, but for most Linux based systems it
2230           will be "both".
2231
2232       --compress-debug-sections=none
2233       --compress-debug-sections=zlib
2234       --compress-debug-sections=zlib-gnu
2235       --compress-debug-sections=zlib-gabi
2236       --compress-debug-sections=zstd
2237           On ELF platforms, these options control how DWARF debug sections
2238           are compressed using zlib.
2239
2240           --compress-debug-sections=none doesn't compress DWARF debug
2241           sections.  --compress-debug-sections=zlib-gnu compresses DWARF
2242           debug sections and renames them to begin with .zdebug instead of
2243           .debug.  --compress-debug-sections=zlib-gabi also compresses DWARF
2244           debug sections, but rather than renaming them it sets the
2245           SHF_COMPRESSED flag in the sections' headers.
2246
2247           The --compress-debug-sections=zlib option is an alias for
2248           --compress-debug-sections=zlib-gabi.
2249
2250           --compress-debug-sections=zstd compresses DWARF debug sections
2251           using zstd.
2252
2253           Note that this option overrides any compression in input debug
2254           sections, so if a binary is linked with
2255           --compress-debug-sections=none for example, then any compressed
2256           debug sections in input files will be uncompressed before they are
2257           copied into the output binary.
2258
2259           The default compression behaviour varies depending upon the target
2260           involved and the configure options used to build the toolchain.
2261           The default can be determined by examining the output from the
2262           linker's --help option.
2263
2264       --reduce-memory-overheads
2265           This option reduces memory requirements at ld runtime, at the
2266           expense of linking speed.  This was introduced to select the old
2267           O(n^2) algorithm for link map file generation, rather than the new
2268           O(n) algorithm which uses about 40% more memory for symbol storage.
2269
2270           Another effect of the switch is to set the default hash table size
2271           to 1021, which again saves memory at the cost of lengthening the
2272           linker's run time.  This is not done however if the --hash-size
2273           switch has been used.
2274
2275           The --reduce-memory-overheads switch may be also be used to enable
2276           other tradeoffs in future versions of the linker.
2277
2278       --max-cache-size=size
2279           ld normally caches the relocation information and symbol tables of
2280           input files in memory with the unlimited size.  This option sets
2281           the maximum cache size to size.
2282
2283       --build-id
2284       --build-id=style
2285           Request the creation of a ".note.gnu.build-id" ELF note section or
2286           a ".buildid" COFF section.  The contents of the note are unique
2287           bits identifying this linked file.  style can be "uuid" to use 128
2288           random bits, "sha1" to use a 160-bit SHA1 hash on the normative
2289           parts of the output contents, "md5" to use a 128-bit MD5 hash on
2290           the normative parts of the output contents, or "0xhexstring" to use
2291           a chosen bit string specified as an even number of hexadecimal
2292           digits ("-" and ":" characters between digit pairs are ignored).
2293           If style is omitted, "sha1" is used.
2294
2295           The "md5" and "sha1" styles produces an identifier that is always
2296           the same in an identical output file, but will be unique among all
2297           nonidentical output files.  It is not intended to be compared as a
2298           checksum for the file's contents.  A linked file may be changed
2299           later by other tools, but the build ID bit string identifying the
2300           original linked file does not change.
2301
2302           Passing "none" for style disables the setting from any "--build-id"
2303           options earlier on the command line.
2304
2305       --package-metadata=JSON
2306           Request the creation of a ".note.package" ELF note section.  The
2307           contents of the note are in JSON format, as per the package
2308           metadata specification.  For more information see:
2309           https://systemd.io/ELF_PACKAGE_METADATA/ If the JSON argument is
2310           missing/empty then this will disable the creation of the metadata
2311           note, if one had been enabled by an earlier occurrence of the
2312           --package-metdata option.  If the linker has been built with
2313           libjansson, then the JSON string will be validated.
2314
2315       The i386 PE linker supports the -shared option, which causes the output
2316       to be a dynamically linked library (DLL) instead of a normal
2317       executable.  You should name the output "*.dll" when you use this
2318       option.  In addition, the linker fully supports the standard "*.def"
2319       files, which may be specified on the linker command line like an object
2320       file (in fact, it should precede archives it exports symbols from, to
2321       ensure that they get linked in, just like a normal object file).
2322
2323       In addition to the options common to all targets, the i386 PE linker
2324       support additional command-line options that are specific to the i386
2325       PE target.  Options that take values may be separated from their values
2326       by either a space or an equals sign.
2327
2328       --add-stdcall-alias
2329           If given, symbols with a stdcall suffix (@nn) will be exported as-
2330           is and also with the suffix stripped.  [This option is specific to
2331           the i386 PE targeted port of the linker]
2332
2333       --base-file file
2334           Use file as the name of a file in which to save the base addresses
2335           of all the relocations needed for generating DLLs with dlltool.
2336           [This is an i386 PE specific option]
2337
2338       --dll
2339           Create a DLL instead of a regular executable.  You may also use
2340           -shared or specify a "LIBRARY" in a given ".def" file.  [This
2341           option is specific to the i386 PE targeted port of the linker]
2342
2343       --enable-long-section-names
2344       --disable-long-section-names
2345           The PE variants of the COFF object format add an extension that
2346           permits the use of section names longer than eight characters, the
2347           normal limit for COFF.  By default, these names are only allowed in
2348           object files, as fully-linked executable images do not carry the
2349           COFF string table required to support the longer names.  As a GNU
2350           extension, it is possible to allow their use in executable images
2351           as well, or to (probably pointlessly!)  disallow it in object
2352           files, by using these two options.  Executable images generated
2353           with these long section names are slightly non-standard, carrying
2354           as they do a string table, and may generate confusing output when
2355           examined with non-GNU PE-aware tools, such as file viewers and
2356           dumpers.  However, GDB relies on the use of PE long section names
2357           to find Dwarf-2 debug information sections in an executable image
2358           at runtime, and so if neither option is specified on the command-
2359           line, ld will enable long section names, overriding the default and
2360           technically correct behaviour, when it finds the presence of debug
2361           information while linking an executable image and not stripping
2362           symbols.  [This option is valid for all PE targeted ports of the
2363           linker]
2364
2365       --enable-stdcall-fixup
2366       --disable-stdcall-fixup
2367           If the link finds a symbol that it cannot resolve, it will attempt
2368           to do "fuzzy linking" by looking for another defined symbol that
2369           differs only in the format of the symbol name (cdecl vs stdcall)
2370           and will resolve that symbol by linking to the match.  For example,
2371           the undefined symbol "_foo" might be linked to the function
2372           "_foo@12", or the undefined symbol "_bar@16" might be linked to the
2373           function "_bar".  When the linker does this, it prints a warning,
2374           since it normally should have failed to link, but sometimes import
2375           libraries generated from third-party dlls may need this feature to
2376           be usable.  If you specify --enable-stdcall-fixup, this feature is
2377           fully enabled and warnings are not printed.  If you specify
2378           --disable-stdcall-fixup, this feature is disabled and such
2379           mismatches are considered to be errors.  [This option is specific
2380           to the i386 PE targeted port of the linker]
2381
2382       --leading-underscore
2383       --no-leading-underscore
2384           For most targets default symbol-prefix is an underscore and is
2385           defined in target's description. By this option it is possible to
2386           disable/enable the default underscore symbol-prefix.
2387
2388       --export-all-symbols
2389           If given, all global symbols in the objects used to build a DLL
2390           will be exported by the DLL.  Note that this is the default if
2391           there otherwise wouldn't be any exported symbols.  When symbols are
2392           explicitly exported via DEF files or implicitly exported via
2393           function attributes, the default is to not export anything else
2394           unless this option is given.  Note that the symbols "DllMain@12",
2395           "DllEntryPoint@0", "DllMainCRTStartup@12", and "impure_ptr" will
2396           not be automatically exported.  Also, symbols imported from other
2397           DLLs will not be re-exported, nor will symbols specifying the DLL's
2398           internal layout such as those beginning with "_head_" or ending
2399           with "_iname".  In addition, no symbols from "libgcc", "libstd++",
2400           "libmingw32", or "crtX.o" will be exported.  Symbols whose names
2401           begin with "__rtti_" or "__builtin_" will not be exported, to help
2402           with C++ DLLs.  Finally, there is an extensive list of cygwin-
2403           private symbols that are not exported (obviously, this applies on
2404           when building DLLs for cygwin targets).  These cygwin-excludes are:
2405           "_cygwin_dll_entry@12", "_cygwin_crt0_common@8",
2406           "_cygwin_noncygwin_dll_entry@12", "_fmode", "_impure_ptr",
2407           "cygwin_attach_dll", "cygwin_premain0", "cygwin_premain1",
2408           "cygwin_premain2", "cygwin_premain3", and "environ".  [This option
2409           is specific to the i386 PE targeted port of the linker]
2410
2411       --exclude-symbols symbol,symbol,...
2412           Specifies a list of symbols which should not be automatically
2413           exported.  The symbol names may be delimited by commas or colons.
2414           [This option is specific to the i386 PE targeted port of the
2415           linker]
2416
2417       --exclude-all-symbols
2418           Specifies no symbols should be automatically exported.  [This
2419           option is specific to the i386 PE targeted port of the linker]
2420
2421       --file-alignment
2422           Specify the file alignment.  Sections in the file will always begin
2423           at file offsets which are multiples of this number.  This defaults
2424           to 512.  [This option is specific to the i386 PE targeted port of
2425           the linker]
2426
2427       --heap reserve
2428       --heap reserve,commit
2429           Specify the number of bytes of memory to reserve (and optionally
2430           commit) to be used as heap for this program.  The default is 1MB
2431           reserved, 4K committed.  [This option is specific to the i386 PE
2432           targeted port of the linker]
2433
2434       --image-base value
2435           Use value as the base address of your program or dll.  This is the
2436           lowest memory location that will be used when your program or dll
2437           is loaded.  To reduce the need to relocate and improve performance
2438           of your dlls, each should have a unique base address and not
2439           overlap any other dlls.  The default is 0x400000 for executables,
2440           and 0x10000000 for dlls.  [This option is specific to the i386 PE
2441           targeted port of the linker]
2442
2443       --kill-at
2444           If given, the stdcall suffixes (@nn) will be stripped from symbols
2445           before they are exported.  [This option is specific to the i386 PE
2446           targeted port of the linker]
2447
2448       --large-address-aware
2449           If given, the appropriate bit in the "Characteristics" field of the
2450           COFF header is set to indicate that this executable supports
2451           virtual addresses greater than 2 gigabytes.  This should be used in
2452           conjunction with the /3GB or /USERVA=value megabytes switch in the
2453           "[operating systems]" section of the BOOT.INI.  Otherwise, this bit
2454           has no effect.  [This option is specific to PE targeted ports of
2455           the linker]
2456
2457       --disable-large-address-aware
2458           Reverts the effect of a previous --large-address-aware option.
2459           This is useful if --large-address-aware is always set by the
2460           compiler driver (e.g. Cygwin gcc) and the executable does not
2461           support virtual addresses greater than 2 gigabytes.  [This option
2462           is specific to PE targeted ports of the linker]
2463
2464       --major-image-version value
2465           Sets the major number of the "image version".  Defaults to 1.
2466           [This option is specific to the i386 PE targeted port of the
2467           linker]
2468
2469       --major-os-version value
2470           Sets the major number of the "os version".  Defaults to 4.  [This
2471           option is specific to the i386 PE targeted port of the linker]
2472
2473       --major-subsystem-version value
2474           Sets the major number of the "subsystem version".  Defaults to 4.
2475           [This option is specific to the i386 PE targeted port of the
2476           linker]
2477
2478       --minor-image-version value
2479           Sets the minor number of the "image version".  Defaults to 0.
2480           [This option is specific to the i386 PE targeted port of the
2481           linker]
2482
2483       --minor-os-version value
2484           Sets the minor number of the "os version".  Defaults to 0.  [This
2485           option is specific to the i386 PE targeted port of the linker]
2486
2487       --minor-subsystem-version value
2488           Sets the minor number of the "subsystem version".  Defaults to 0.
2489           [This option is specific to the i386 PE targeted port of the
2490           linker]
2491
2492       --output-def file
2493           The linker will create the file file which will contain a DEF file
2494           corresponding to the DLL the linker is generating.  This DEF file
2495           (which should be called "*.def") may be used to create an import
2496           library with "dlltool" or may be used as a reference to
2497           automatically or implicitly exported symbols.  [This option is
2498           specific to the i386 PE targeted port of the linker]
2499
2500       --enable-auto-image-base
2501       --enable-auto-image-base=value
2502           Automatically choose the image base for DLLs, optionally starting
2503           with base value, unless one is specified using the "--image-base"
2504           argument.  By using a hash generated from the dllname to create
2505           unique image bases for each DLL, in-memory collisions and
2506           relocations which can delay program execution are avoided.  [This
2507           option is specific to the i386 PE targeted port of the linker]
2508
2509       --disable-auto-image-base
2510           Do not automatically generate a unique image base.  If there is no
2511           user-specified image base ("--image-base") then use the platform
2512           default.  [This option is specific to the i386 PE targeted port of
2513           the linker]
2514
2515       --dll-search-prefix string
2516           When linking dynamically to a dll without an import library, search
2517           for "<string><basename>.dll" in preference to "lib<basename>.dll".
2518           This behaviour allows easy distinction between DLLs built for the
2519           various "subplatforms": native, cygwin, uwin, pw, etc.  For
2520           instance, cygwin DLLs typically use "--dll-search-prefix=cyg".
2521           [This option is specific to the i386 PE targeted port of the
2522           linker]
2523
2524       --enable-auto-import
2525           Do sophisticated linking of "_symbol" to "__imp__symbol" for DATA
2526           imports from DLLs, thus making it possible to bypass the dllimport
2527           mechanism on the user side and to reference unmangled symbol names.
2528           [This option is specific to the i386 PE targeted port of the
2529           linker]
2530
2531           The following remarks pertain to the original implementation of the
2532           feature and are obsolete nowadays for Cygwin and MinGW targets.
2533
2534           Note: Use of the 'auto-import' extension will cause the text
2535           section of the image file to be made writable. This does not
2536           conform to the PE-COFF format specification published by Microsoft.
2537
2538           Note - use of the 'auto-import' extension will also cause read only
2539           data which would normally be placed into the .rdata section to be
2540           placed into the .data section instead.  This is in order to work
2541           around a problem with consts that is described here:
2542           http://www.cygwin.com/ml/cygwin/2004-09/msg01101.html
2543
2544           Using 'auto-import' generally will 'just work' -- but sometimes you
2545           may see this message:
2546
2547           "variable '<var>' can't be auto-imported. Please read the
2548           documentation for ld's "--enable-auto-import" for details."
2549
2550           This message occurs when some (sub)expression accesses an address
2551           ultimately given by the sum of two constants (Win32 import tables
2552           only allow one).  Instances where this may occur include accesses
2553           to member fields of struct variables imported from a DLL, as well
2554           as using a constant index into an array variable imported from a
2555           DLL.  Any multiword variable (arrays, structs, long long, etc) may
2556           trigger this error condition.  However, regardless of the exact
2557           data type of the offending exported variable, ld will always detect
2558           it, issue the warning, and exit.
2559
2560           There are several ways to address this difficulty, regardless of
2561           the data type of the exported variable:
2562
2563           One way is to use --enable-runtime-pseudo-reloc switch. This leaves
2564           the task of adjusting references in your client code for runtime
2565           environment, so this method works only when runtime environment
2566           supports this feature.
2567
2568           A second solution is to force one of the 'constants' to be a
2569           variable -- that is, unknown and un-optimizable at compile time.
2570           For arrays, there are two possibilities: a) make the indexee (the
2571           array's address) a variable, or b) make the 'constant' index a
2572           variable.  Thus:
2573
2574                   extern type extern_array[];
2575                   extern_array[1] -->
2576                      { volatile type *t=extern_array; t[1] }
2577
2578           or
2579
2580                   extern type extern_array[];
2581                   extern_array[1] -->
2582                      { volatile int t=1; extern_array[t] }
2583
2584           For structs (and most other multiword data types) the only option
2585           is to make the struct itself (or the long long, or the ...)
2586           variable:
2587
2588                   extern struct s extern_struct;
2589                   extern_struct.field -->
2590                      { volatile struct s *t=&extern_struct; t->field }
2591
2592           or
2593
2594                   extern long long extern_ll;
2595                   extern_ll -->
2596                     { volatile long long * local_ll=&extern_ll; *local_ll }
2597
2598           A third method of dealing with this difficulty is to abandon
2599           'auto-import' for the offending symbol and mark it with
2600           "__declspec(dllimport)".  However, in practice that requires using
2601           compile-time #defines to indicate whether you are building a DLL,
2602           building client code that will link to the DLL, or merely
2603           building/linking to a static library.   In making the choice
2604           between the various methods of resolving the 'direct address with
2605           constant offset' problem, you should consider typical real-world
2606           usage:
2607
2608           Original:
2609
2610                   --foo.h
2611                   extern int arr[];
2612                   --foo.c
2613                   #include "foo.h"
2614                   void main(int argc, char **argv){
2615                     printf("%d\n",arr[1]);
2616                   }
2617
2618           Solution 1:
2619
2620                   --foo.h
2621                   extern int arr[];
2622                   --foo.c
2623                   #include "foo.h"
2624                   void main(int argc, char **argv){
2625                     /* This workaround is for win32 and cygwin; do not "optimize" */
2626                     volatile int *parr = arr;
2627                     printf("%d\n",parr[1]);
2628                   }
2629
2630           Solution 2:
2631
2632                   --foo.h
2633                   /* Note: auto-export is assumed (no __declspec(dllexport)) */
2634                   #if (defined(_WIN32) || defined(__CYGWIN__)) && \
2635                     !(defined(FOO_BUILD_DLL) || defined(FOO_STATIC))
2636                   #define FOO_IMPORT __declspec(dllimport)
2637                   #else
2638                   #define FOO_IMPORT
2639                   #endif
2640                   extern FOO_IMPORT int arr[];
2641                   --foo.c
2642                   #include "foo.h"
2643                   void main(int argc, char **argv){
2644                     printf("%d\n",arr[1]);
2645                   }
2646
2647           A fourth way to avoid this problem is to re-code your library to
2648           use a functional interface rather than a data interface for the
2649           offending variables (e.g. set_foo() and get_foo() accessor
2650           functions).
2651
2652       --disable-auto-import
2653           Do not attempt to do sophisticated linking of "_symbol" to
2654           "__imp__symbol" for DATA imports from DLLs.  [This option is
2655           specific to the i386 PE targeted port of the linker]
2656
2657       --enable-runtime-pseudo-reloc
2658           If your code contains expressions described in --enable-auto-import
2659           section, that is, DATA imports from DLL with non-zero offset, this
2660           switch will create a vector of 'runtime pseudo relocations' which
2661           can be used by runtime environment to adjust references to such
2662           data in your client code.  [This option is specific to the i386 PE
2663           targeted port of the linker]
2664
2665       --disable-runtime-pseudo-reloc
2666           Do not create pseudo relocations for non-zero offset DATA imports
2667           from DLLs.  [This option is specific to the i386 PE targeted port
2668           of the linker]
2669
2670       --enable-extra-pe-debug
2671           Show additional debug info related to auto-import symbol thunking.
2672           [This option is specific to the i386 PE targeted port of the
2673           linker]
2674
2675       --section-alignment
2676           Sets the section alignment.  Sections in memory will always begin
2677           at addresses which are a multiple of this number.  Defaults to
2678           0x1000.  [This option is specific to the i386 PE targeted port of
2679           the linker]
2680
2681       --stack reserve
2682       --stack reserve,commit
2683           Specify the number of bytes of memory to reserve (and optionally
2684           commit) to be used as stack for this program.  The default is 2MB
2685           reserved, 4K committed.  [This option is specific to the i386 PE
2686           targeted port of the linker]
2687
2688       --subsystem which
2689       --subsystem which:major
2690       --subsystem which:major.minor
2691           Specifies the subsystem under which your program will execute.  The
2692           legal values for which are "native", "windows", "console", "posix",
2693           and "xbox".  You may optionally set the subsystem version also.
2694           Numeric values are also accepted for which.  [This option is
2695           specific to the i386 PE targeted port of the linker]
2696
2697           The following options set flags in the "DllCharacteristics" field
2698           of the PE file header: [These options are specific to PE targeted
2699           ports of the linker]
2700
2701       --high-entropy-va
2702       --disable-high-entropy-va
2703           Image is compatible with 64-bit address space layout randomization
2704           (ASLR).  This option is enabled by default for 64-bit PE images.
2705
2706           This option also implies --dynamicbase and --enable-reloc-section.
2707
2708       --dynamicbase
2709       --disable-dynamicbase
2710           The image base address may be relocated using address space layout
2711           randomization (ASLR).  This feature was introduced with MS Windows
2712           Vista for i386 PE targets.  This option is enabled by default but
2713           can be disabled via the --disable-dynamicbase option.  This option
2714           also implies --enable-reloc-section.
2715
2716       --forceinteg
2717       --disable-forceinteg
2718           Code integrity checks are enforced.  This option is disabled by
2719           default.
2720
2721       --nxcompat
2722       --disable-nxcompat
2723           The image is compatible with the Data Execution Prevention.  This
2724           feature was introduced with MS Windows XP SP2 for i386 PE targets.
2725           The option is enabled by default.
2726
2727       --no-isolation
2728       --disable-no-isolation
2729           Although the image understands isolation, do not isolate the image.
2730           This option is disabled by default.
2731
2732       --no-seh
2733       --disable-no-seh
2734           The image does not use SEH. No SE handler may be called from this
2735           image.  This option is disabled by default.
2736
2737       --no-bind
2738       --disable-no-bind
2739           Do not bind this image.  This option is disabled by default.
2740
2741       --wdmdriver
2742       --disable-wdmdriver
2743           The driver uses the MS Windows Driver Model.  This option is
2744           disabled by default.
2745
2746       --tsaware
2747       --disable-tsaware
2748           The image is Terminal Server aware.  This option is disabled by
2749           default.
2750
2751       --insert-timestamp
2752       --no-insert-timestamp
2753           Insert a real timestamp into the image.  This is the default
2754           behaviour as it matches legacy code and it means that the image
2755           will work with other, proprietary tools.  The problem with this
2756           default is that it will result in slightly different images being
2757           produced each time the same sources are linked.  The option
2758           --no-insert-timestamp can be used to insert a zero value for the
2759           timestamp, this ensuring that binaries produced from identical
2760           sources will compare identically.
2761
2762       --enable-reloc-section
2763       --disable-reloc-section
2764           Create the base relocation table, which is necessary if the image
2765           is loaded at a different image base than specified in the PE
2766           header.  This option is enabled by default.
2767
2768       The C6X uClinux target uses a binary format called DSBT to support
2769       shared libraries.  Each shared library in the system needs to have a
2770       unique index; all executables use an index of 0.
2771
2772       --dsbt-size size
2773           This option sets the number of entries in the DSBT of the current
2774           executable or shared library to size.  The default is to create a
2775           table with 64 entries.
2776
2777       --dsbt-index index
2778           This option sets the DSBT index of the current executable or shared
2779           library to index.  The default is 0, which is appropriate for
2780           generating executables.  If a shared library is generated with a
2781           DSBT index of 0, the "R_C6000_DSBT_INDEX" relocs are copied into
2782           the output file.
2783
2784           The --no-merge-exidx-entries switch disables the merging of
2785           adjacent exidx entries in frame unwind info.
2786
2787       --branch-stub
2788           This option enables linker branch relaxation by inserting branch
2789           stub sections when needed to extend the range of branches.  This
2790           option is usually not required since C-SKY supports branch and call
2791           instructions that can access the full memory range and branch
2792           relaxation is normally handled by the compiler or assembler.
2793
2794       --stub-group-size=N
2795           This option allows finer control of linker branch stub creation.
2796           It sets the maximum size of a group of input sections that can be
2797           handled by one stub section.  A negative value of N locates stub
2798           sections after their branches, while a positive value allows stub
2799           sections to appear either before or after the branches.  Values of
2800           1 or -1 indicate that the linker should choose suitable defaults.
2801
2802       The 68HC11 and 68HC12 linkers support specific options to control the
2803       memory bank switching mapping and trampoline code generation.
2804
2805       --no-trampoline
2806           This option disables the generation of trampoline. By default a
2807           trampoline is generated for each far function which is called using
2808           a "jsr" instruction (this happens when a pointer to a far function
2809           is taken).
2810
2811       --bank-window name
2812           This option indicates to the linker the name of the memory region
2813           in the MEMORY specification that describes the memory bank window.
2814           The definition of such region is then used by the linker to compute
2815           paging and addresses within the memory window.
2816
2817       The following options are supported to control handling of GOT
2818       generation when linking for 68K targets.
2819
2820       --got=type
2821           This option tells the linker which GOT generation scheme to use.
2822           type should be one of single, negative, multigot or target.  For
2823           more information refer to the Info entry for ld.
2824
2825       The following options are supported to control microMIPS instruction
2826       generation and branch relocation checks for ISA mode transitions when
2827       linking for MIPS targets.
2828
2829       --insn32
2830       --no-insn32
2831           These options control the choice of microMIPS instructions used in
2832           code generated by the linker, such as that in the PLT or lazy
2833           binding stubs, or in relaxation.  If --insn32 is used, then the
2834           linker only uses 32-bit instruction encodings.  By default or if
2835           --no-insn32 is used, all instruction encodings are used, including
2836           16-bit ones where possible.
2837
2838       --ignore-branch-isa
2839       --no-ignore-branch-isa
2840           These options control branch relocation checks for invalid ISA mode
2841           transitions.  If --ignore-branch-isa is used, then the linker
2842           accepts any branch relocations and any ISA mode transition required
2843           is lost in relocation calculation, except for some cases of "BAL"
2844           instructions which meet relaxation conditions and are converted to
2845           equivalent "JALX" instructions as the associated relocation is
2846           calculated.  By default or if --no-ignore-branch-isa is used a
2847           check is made causing the loss of an ISA mode transition to produce
2848           an error.
2849
2850       --compact-branches
2851       --no-compact-branches
2852           These options control the generation of compact instructions by the
2853           linker in the PLT entries for MIPS R6.
2854
2855       For the pdp11-aout target, three variants of the output format can be
2856       produced as selected by the following options.  The default variant for
2857       pdp11-aout is the --omagic option, whereas for other targets --nmagic
2858       is the default.  The --imagic option is defined only for the pdp11-aout
2859       target, while the others are described here as they apply to the
2860       pdp11-aout target.
2861
2862       -N
2863       --omagic
2864           Mark the output as "OMAGIC" (0407) in the a.out header to indicate
2865           that the text segment is not to be write-protected and shared.
2866           Since the text and data sections are both readable and writable,
2867           the data section is allocated immediately contiguous after the text
2868           segment.  This is the oldest format for PDP11 executable programs
2869           and is the default for ld on PDP11 Unix systems from the beginning
2870           through 2.11BSD.
2871
2872       -n
2873       --nmagic
2874           Mark the output as "NMAGIC" (0410) in the a.out header to indicate
2875           that when the output file is executed, the text portion will be
2876           read-only and shareable among all processes executing the same
2877           file.  This involves moving the data areas up to the first possible
2878           8K byte page boundary following the end of the text.  This option
2879           creates a pure executable format.
2880
2881       -z
2882       --imagic
2883           Mark the output as "IMAGIC" (0411) in the a.out header to indicate
2884           that when the output file is executed, the program text and data
2885           areas will be loaded into separate address spaces using the split
2886           instruction and data space feature of the memory management unit in
2887           larger models of the PDP11.  This doubles the address space
2888           available to the program.  The text segment is again pure, write-
2889           protected, and shareable.  The only difference in the output format
2890           between this option and the others, besides the magic number, is
2891           that both the text and data sections start at location 0.  The -z
2892           option selected this format in 2.11BSD.  This option creates a
2893           separate executable format.
2894
2895       --no-omagic
2896           Equivalent to --nmagic for pdp11-aout.
2897

ENVIRONMENT

2899       You can change the behaviour of ld with the environment variables
2900       "GNUTARGET", "LDEMULATION" and "COLLECT_NO_DEMANGLE".
2901
2902       "GNUTARGET" determines the input-file object format if you don't use -b
2903       (or its synonym --format).  Its value should be one of the BFD names
2904       for an input format.  If there is no "GNUTARGET" in the environment, ld
2905       uses the natural format of the target. If "GNUTARGET" is set to
2906       "default" then BFD attempts to discover the input format by examining
2907       binary input files; this method often succeeds, but there are potential
2908       ambiguities, since there is no method of ensuring that the magic number
2909       used to specify object-file formats is unique.  However, the
2910       configuration procedure for BFD on each system places the conventional
2911       format for that system first in the search-list, so ambiguities are
2912       resolved in favor of convention.
2913
2914       "LDEMULATION" determines the default emulation if you don't use the -m
2915       option.  The emulation can affect various aspects of linker behaviour,
2916       particularly the default linker script.  You can list the available
2917       emulations with the --verbose or -V options.  If the -m option is not
2918       used, and the "LDEMULATION" environment variable is not defined, the
2919       default emulation depends upon how the linker was configured.
2920
2921       Normally, the linker will default to demangling symbols.  However, if
2922       "COLLECT_NO_DEMANGLE" is set in the environment, then it will default
2923       to not demangling symbols.  This environment variable is used in a
2924       similar fashion by the "gcc" linker wrapper program.  The default may
2925       be overridden by the --demangle and --no-demangle options.
2926

SEE ALSO

2928       ar(1), nm(1), objcopy(1), objdump(1), readelf(1) and the Info entries
2929       for binutils and ld.
2930
2932       Copyright (c) 1991-2023 Free Software Foundation, Inc.
2933
2934       Permission is granted to copy, distribute and/or modify this document
2935       under the terms of the GNU Free Documentation License, Version 1.3 or
2936       any later version published by the Free Software Foundation; with no
2937       Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
2938       Texts.  A copy of the license is included in the section entitled "GNU
2939       Free Documentation License".
2940
2941
2942
2943binutils-2.40.00                  2023-01-14                             LD(1)
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