ld/gld.1

   1 .\" Copyright (c) 1991, 1992 Free Software Foundation
   2 .\" See section COPYING for conditions for redistribution
   3 .TH gld 1 "23 January 1992" "cygnus support" "GNU Development Tools"
   4 .de BP
   5 .sp
   6 .ti \-.2i
   7 \(**
   8 ..
   9
  10 .SH NAME
  11 gld \- the GNU linker
  12
  13 .SH SYNOPSIS
  14 .hy 0
  15 .na
  16 .TP
  17 .B gld
  18 .RB "[\|" \-o "
  19 .I output\c
  20 \&\|] \c
  21 .I objfiles\c
  22 \&.\|.\|.
  23 .br
  24 .RB "[\|" \-A\c
  25 .I architecture\c
  26 \&\|]
  27 .RB "[\|" "\-b\ "\c
  28 .I input-format\c
  29 \&\|]
  30 .RB "[\|" \-Bstatic "\|]"
  31 .RB "[\|" "\-c\ "\c
  32 .I commandfile\c
  33 \&\|]
  34 .RB "[\|" \-d | \-dc | \-dp\c
  35 \|]
  36 .br
  37 .RB "[\|" "\-defsym\ "\c
  38 .I symbol\c
  39 \& = \c
  40 .I expression\c
  41 \&\|]
  42 .RB "[\|" "\-e\ "\c
  43 .I entry\c
  44 \&\|]
  45 .RB "[\|" \-F "\|]"
  46 .RB "[\|" "\-F\ "\c
  47 .I format\c
  48 \&\|]
  49 .RB "[\|" "\-format\ "\c
  50 .I input-format\c
  51 \&\|]
  52 .RB "[\|" \-g "\|]"
  53 .RB "[\|" \-i "\|]"
  54 .RB "[\|" \-l\c
  55 .I ar\c
  56 \&\|]
  57 .RB "[\|" \-L\c
  58 .I searchdir\c
  59 \&\|]
  60 .RB "[\|" \-M | \-m "\|]"
  61 .RB "[\|" \-n | \-N "\|]"
  62 .RB "[\|" \-noinhibit-exec "\|]"
  63 .RB "[\|" "\-R\ "\c
  64 .I filename\c
  65 \&\|]
  66 .RB "[\|" \-relax "\|]"
  67 .RB "[\|" \-r | \-Ur "\|]"
  68 .RB "[\|" \-S "\|]"
  69 .RB "[\|" \-s "\|]"
  70 .RB "[\|" "\-T\ "\c
  71 .I commandfile\c
  72 \&\|]
  73 .RB "[\|" "\-Ttext\ "\c
  74 .I textorg\c
  75 \&\|]
  76 .RB "[\|" "\-Tdata\ "\c
  77 .I dataorg\c
  78 \&\|]
  79 .RB "[\|" "\-Tbss\ "\c
  80 .I bssorg\c
  81 \&\|]
  82 .RB "[\|" \-t "\|]"
  83 .RB "[\|" "\-u\ "\c
  84 .I sym\c
  85 \&]
  86 .RB "[\|" \-v "\|]"
  87 .RB "[\|" \-X "\|]"
  88 .RB "[\|" \-x "\|]"
  89 .RB "[\|" { \c
  90 .I script\c
  91 .BR } "\|]"
  92 .ad b
  93 .hy 1
  94 .SH DESCRIPTION
  95 \c
  96 .B gld\c
  97 \& combines a number of object and archive files, relocates
  98 their data and ties up symbol references. Often the last step in
  99 building a new compiled program to run is a call to \c
 100 .B gld\c
 101 \&.
 102
 103 \c
 104 .B gld\c
 105 \& accepts Linker Command Language files
 106 to provide explicit and total control over the linking process.
 107 This man page does not describe the command language; see the `\|\c
 108 .B ld\c
 109 \|' entry in `\|\c
 110 .B info\c
 111 \|', or the manual
 112 .I
 113 gld: the GNU linker
 114 \&, for full details on the command language and on other aspects of
 115 the GNU linker.
 116
 117 This version of \c
 118 .B gld\c
 119 \& uses the general purpose BFD libraries
 120 to operate on object files. This allows \c
 121 .B gld\c
 122 \& to read, combine, and
 123 write object files in many different formats\(em\&for example, COFF or
 124 \c
 125 .B a.out\c
 126 \&.  Different formats may be linked together to produce any
 127 available kind of object file.  You can use `\|\c
 128 .B objdump \-i\c
 129 \|' to get a list of formats supported on various architectures; see
 130 .BR objdump ( 1 ).
 131
 132 Aside from its flexibility, the GNU linker is more helpful than other
 133 linkers in providing diagnostic information.  Many linkers abandon
 134 execution immediately upon encountering an error; whenever possible,
 135 \c
 136 .B gld\c
 137 \& continues executing, allowing you to identify other errors
 138 (or, in some cases, to get an output file in spite of the error).
 139
 140 The GNU linker \c
 141 .B gld\c
 142 \& is meant to cover a broad range of situations,
 143 and to be as compatible as possible with other linkers.  As a result,
 144 you have many choices to control its behavior through the command line,
 145 and through environment variables.
 146
 147 .SH OPTIONS
 148 The plethora of command-line options may seem intimidating, but in
 149 actual practice few of them are used in any particular context.
 150 For instance, a frequent use of \c
 151 .B gld\c
 152 \& is to link standard Unix
 153 object files on a standard, supported Unix system.  On such a system, to
 154 link a file \c
 155 .B hello.o\c
 156 \&:
 157 .sp
 158 .br
 159 $\ gld\ \-o\ output\ /lib/crt0.o\ hello.o\ \-lc
 160 .br
 161 .sp
 162 This tells \c
 163 .B gld\c
 164 \& to produce a file called \c
 165 .B output\c
 166 \& as the
 167 result of linking the file \c
 168 .B /lib/crt0.o\c
 169 \& with \c
 170 .B hello.o\c
 171 \& and
 172 the library \c
 173 .B libc.a\c
 174 \& which will come from the standard search
 175 directories.
 176
 177 The command-line options to \c
 178 .B gld\c
 179 \& may be specified in any order, and
 180 may be repeated at will.  For the most part, repeating an option with a
 181 different argument will either have no further effect, or override prior
 182 occurrences (those further to the left on the command line) of an
 183 option.
 184
 185 The exceptions\(em\&which may meaningfully be used more than once\(em\&are
 186 \c
 187 .B \-A\c
 188 \&, \c
 189 .B \-b\c
 190 \& (or its synonym \c
 191 .B \-format\c
 192 \&), \c
 193 .B \-defsym\c
 194 \&,
 195 \c
 196 .B \-L\c
 197 \&, \c
 198 .B \-l\c
 199 \&, \c
 200 .B \-R\c
 201 \&, and \c
 202 .B \-u\c
 203 \&.
 204
 205 The list of object files to be linked together, shown as \c
 206 .I objfiles\c
 207 \&,
 208 may follow, precede, or be mixed in with command-line options; save that
 209 an \c
 210 .I objfiles\c
 211 \& argument may not be placed between an option flag and
 212 its argument.
 213
 214 Usually the linker is invoked with at least one object file, but other
 215 forms of binary input files can also be specified with \c
 216 .B \-l\c
 217 \&,
 218 \c
 219 .B \-R\c
 220 \&, and the script command language.  If \c
 221 .I no\c
 222 \& binary input
 223 files at all are specified, the linker does not produce any output, and
 224 issues the message `\|\c
 225 .B No input files\c
 226 \|'.
 227
 228 Option arguments must either follow the option letter without intervening
 229 whitespace, or be given as separate arguments immediately following the
 230 option that requires them.
 231
 232 .TP
 233 .IR "objfiles" .\|.\|.
 234 The object files \c
 235 .I objfiles\c
 236 \& to be linked.
 237
 238 .TP
 239 .BI "-A" "architecture"\c
 240 \&
 241 In the current release of \c
 242 .B gld\c
 243 \&, this option is useful only for the
 244 Intel 960 family of architectures.  In that \c
 245 .B gld\c
 246 \& configuration, the
 247 \c
 248 .I architecture\c
 249 \& argument is one of the two-letter names identifying
 250 members of the 960 family; the option specifies the desired output
 251 target, and warns of any incompatible instructions in the input files.
 252 It also modifies the linker's search strategy for archive libraries, to
 253 support the use of libraries specific to each particular
 254 architecture, by including in the search loop names suffixed with the
 255 string identifying the architecture.
 256
 257 For example, if your \c
 258 .B gld\c
 259 \& command line included `\|\c
 260 .B \-ACA\c
 261 \|' as
 262 well as `\|\c
 263 .B \-ltry\c
 264 \|', the linker would look (in its built-in search
 265 paths, and in any paths you specify with \c
 266 .B \-L\c
 267 \&) for a library with
 268 the names
 269 .sp
 270 .br
 271 try
 272 .br
 273 libtry.a
 274 .br
 275 tryca
 276 .br
 277 libtryca.a
 278 .br
 279 .sp
 280
 281 The first two possibilities would be considered in any event; the last
 282 two are due to the use of `\|\c
 283 .B \-ACA\c
 284 \|'.
 285
 286 Future releases of \c
 287 .B gld\c
 288 \& may support similar functionality for
 289 other architecture families.
 290
 291 You can meaningfully use \c
 292 .B \-A\c
 293 \& more than once on a command line, if
 294 an architecture family allows combination of target architectures; each
 295 use will add another pair of name variants to search for when \c
 296 .B \-l\c
 297 \&
 298 specifies a library.
 299
 300 .TP
 301 .BI "-b " "input-format"\c
 302 \&
 303 Specify the binary format for input object files that follow this option
 304 on the command line.  You don't usually need to specify this, as
 305 \c
 306 .B gld\c
 307 \& is configured to expect as a default input format the most
 308 usual format on each machine.  \c
 309 .I input-format\c
 310 \& is a text string, the
 311 name of a particular format supported by the BFD libraries.
 312 \c
 313 .B \-format \c
 314 .I input-format\c
 315 \&\c
 316 \& has the same effect.
 317
 318 You may want to use this option if you are linking files with an unusual
 319 binary format.  You can also use \c
 320 .B \-b\c
 321 \& to switch formats explicitly (when
 322 linking object files of different formats), by including
 323 \c
 324 .B \-b \c
 325 .I input-format\c
 326 \&\c
 327 \& before each group of object files in a
 328 particular format.
 329
 330 The default format is taken from the environment variable
 331 .B GNUTARGET\c
 332 \&.  You can also define the input
 333 format from a script, using the command \c
 334 .B TARGET\c
 335 \&.
 336
 337 .TP
 338 .B \-Bstatic
 339 This flag is accepted for command-line compatibility with the SunOS linker,
 340 but has no effect on \c
 341 .B gld\c
 342 \&.
 343
 344 .TP
 345 .BI "-c " "commandfile"\c
 346 \&
 347 Directs \c
 348 .B gld\c
 349 \& to read link commands from the file
 350 \c
 351 .I commandfile\c
 352 \&.  These commands will completely override \c
 353 .B gld\c
 354 \&'s
 355 default link format (rather than adding to it); \c
 356 .I commandfile\c
 357 \& must
 358 specify everything necessary to describe the target format.
 359
 360
 361 You may also include a script of link commands directly in the command
 362 line by bracketing it between `\|\c
 363 .B {\c
 364 \|' and `\|\c
 365 .B }\c
 366 \|' characters.
 367
 368 .TP
 369 .B \-d
 370 .TP
 371 .B \-dc
 372 .TP
 373 .B \-dp
 374 These three options are equivalent; multiple forms are supported for
 375 compatibility with other linkers.  Use any of them to make \c
 376 .B ld\c
 377 \&
 378 assign space to common symbols even if a relocatable output file is
 379 specified (\c
 380 .B \-r\c
 381 \&).  The script command
 382 \c
 383 .B FORCE_COMMON_ALLOCATION\c
 384 \& has the same effect.
 385
 386 .TP
 387 .BI "-defsym " "symbol"\c
 388 \& = \c
 389 .I expression\c
 390 \&
 391 Create a global symbol in the output file, containing the absolute
 392 address given by \c
 393 .I expression\c
 394 \&.  You may use this option as many
 395 times as necessary to define multiple symbols in the command line.  A
 396 limited form of arithmetic is supported for the \c
 397 .I expression\c
 398 \& in this
 399 context: you may give a hexadecimal constant or the name of an existing
 400 symbol, or use \c
 401 .B +\c
 402 \& and \c
 403 .B \-\c
 404 \& to add or subtract hexadecimal
 405 constants or symbols.  If you need more elaborate expressions, consider
 406 using the linker command language from a script.
 407
 408 .TP
 409 .BI "-e " "entry"\c
 410 \&
 411 Use \c
 412 .I entry\c
 413 \& as the explicit symbol for beginning execution of your
 414 program, rather than the default entry point.  for a
 415 discussion of defaults and other ways of specifying the
 416 entry point.
 417
 418 .TP
 419 .B \-F
 420 .TP
 421 .BI "-F" "format"\c
 422 \&
 423 Some older linkers used this option throughout a compilation toolchain
 424 for specifying object-file format for both input and output object
 425 files.  \c
 426 .B gld\c
 427 \&'s mechanisms (the \c
 428 .B \-b\c
 429 \& or \c
 430 .B \-format\c
 431 \& options
 432 for input files, the \c
 433 .B TARGET\c
 434 \& command in linker scripts for output
 435 files, the \c
 436 .B GNUTARGET\c
 437 \& environment variable) are more flexible, but
 438 but it accepts (and ignores) the \c
 439 .B \-F\c
 440 \& option flag for compatibility
 441 with scripts written to call the old linker.
 442
 443 .TP
 444 .BI "-format " "input-format"\c
 445 \&
 446 Synonym for \c
 447 .B \-b\c
 448 \& \c
 449 .I input-format\c
 450 \&.
 451
 452 .TP
 453 .B \-g
 454 Accepted, but ignored; provided for compatibility with other tools.
 455
 456 .TP
 457 .B \-i
 458 Perform an incremental link (same as option \c
 459 .B \-r\c
 460 \&).
 461
 462 .TP
 463 .BI "-l" "ar"\c
 464 \&
 465 Add an archive file \c
 466 .I ar\c
 467 \& to the list of files to link.  This
 468 option may be used any number of times.  \c
 469 .B ld\c
 470 \& will search its
 471 path-list for occurrences of \c
 472 .B lib\c
 473 .I ar\c
 474 \&.a\c
 475 \& for every \c
 476 .I ar\c
 477 \&
 478 specified.
 479
 480 .TP
 481 .BI "-L" "searchdir"\c
 482 \&
 483 This command adds path \c
 484 .I searchdir\c
 485 \& to the list of paths that
 486 \c
 487 .B gld\c
 488 \& will search for archive libraries.  You may use this option
 489 any number of times.
 490
 491 The default set of paths searched (without being specified with
 492 \c
 493 .B \-L\c
 494 \&) depends on what emulation mode \c
 495 .B gld\c
 496 \& is using, and in
 497 some cases also on how it was configured.    The
 498 paths can also be specified in a link script with the \c
 499 .B SEARCH_DIR\c
 500 \&
 501 command.
 502
 503 .TP
 504 .B \-M
 505 .TP
 506 .B \-m
 507 Print (to the standard output file) a link map\(em\&diagnostic information
 508 about where symbols are mapped by \c
 509 .B ld\c
 510 \&, and information on global
 511 common storage allocation.
 512
 513 .TP
 514 .B \-N
 515 specifies readable and writable \c
 516 .B text\c
 517 \& and \c
 518 .B data\c
 519 \& sections. If
 520 the output format supports Unix style magic numbers, the output is
 521 marked as \c
 522 .B OMAGIC\c
 523 \&.
 524
 525 When you use the `\|\c
 526 .B \-N\c
 527 \&\|' option, the linker does not page-align the
 528 data segment.
 529
 530 .TP
 531 .B \-n
 532 sets the text segment to be read only, and \c
 533 .B NMAGIC\c
 534 \& is written
 535 if possible.
 536
 537 .TP
 538 .B \-noinhibit-exec
 539 Normally, the linker will not produce an output file if it encounters
 540 errors during the link process.  With this flag, you can specify that
 541 you wish the output file retained even after non-fatal errors.
 542
 543 .TP
 544 .BI "-o " "output"\c
 545 \&
 546 .I output\c
 547 \&
 548 \c
 549 .I output\c
 550 \& is a name for the program produced by \c
 551 .B ld\c
 552 \&; if this
 553 option is not specified, the name `\|\c
 554 .B a.out\c
 555 \|' is used by default.  The
 556 script command \c
 557 .B OUTPUT\c
 558 \& can also specify the output file name.
 559
 560 .TP
 561 .BI "-R " "filename"\c
 562 \&
 563 .I file\c
 564 \&
 565 Read symbol names and their addresses from \c
 566 .I filename\c
 567 \&, but do not
 568 relocate it or include it in the output.  This allows your output file
 569 to refer symbolically to absolute locations of memory defined in other
 570 programs.
 571
 572 .TP
 573 .B \-relax
 574 An option with machine dependent effects.  Currently this option is only
 575 supported on the H8/300.
 576
 577 On some platforms, use this option to perform global optimizations that
 578 become possible when the linker resolves addressing in your program, such
 579 as relaxing address modes and synthesizing new instructions in the
 580 output object file.
 581
 582 On platforms where this is not supported, `\|\c
 583 .B \-relax\c
 584 \&\|' is accepted, but has no effect.
 585
 586 .TP
 587 .B \-r
 588 Generates relocatable output\(em\&i.e., generate an output file that can in
 589 turn serve as input to \c
 590 .B gld\c
 591 \&.  This is often called \c
 592 .I partial
 593 linking\c
 594 \&.  As a side effect, in environments that support standard Unix
 595 magic numbers, this option also sets the output file's magic number to
 596 \c
 597 .B OMAGIC\c
 598 \&.
 599 If this option is not specified, an absolute file is produced.  When
 600 linking C++ programs, this option \c
 601 .I will not\c
 602 \& resolve references to
 603 constructors; \c
 604 .B \-Ur\c
 605 \& is an alternative.
 606
 607 This option does the same as \c
 608 .B \-i\c
 609 \&.
 610
 611 .TP
 612 .B \-S
 613 Omits debugger symbol information (but not all symbols) from the output file.
 614
 615 .TP
 616 .B \-s
 617 Omits all symbol information from the output file.
 618
 619 .TP
 620 .BI "{ " "script" " }"
 621 You can, if you wish, include a script of linker commands directly in
 622 the command line instead of referring to it via an input file.  When the
 623 character `\|\c
 624 .B {\c
 625 \|' occurs on the command line, the linker switches to
 626 interpreting the command language until the end of the list of commands
 627 is reached\(em\&flagged with a closing brace `\|\c
 628 .B }\c
 629 \|'.  Other command-line
 630 options will not be recognized while parsing the script.
 631 for a description of the command language.
 632
 633 .TP
 634 .BI "-Tbss " "org"\c
 635 .TP
 636 .BI "-Tdata " "org"\c
 637 .TP
 638 .BI "-Ttext " "org"\c
 639 Use \c
 640 .I org\c
 641 \& as the starting address for\(em\&respectively\(em\&the
 642 \c
 643 .B bss\c
 644 \&, \c
 645 .B data\c
 646 \&, or the \c
 647 .B text\c
 648 \& segment of the output file.
 649 \c
 650 .I textorg\c
 651 \& must be a hexadecimal integer.
 652
 653 .TP
 654 .BI "-T " "commandfile"\c
 655 \&
 656 .TP
 657 .BI "-T" "commandfile"\c
 658 Equivalent to \c
 659 .B \-c \c
 660 .I commandfile\c
 661 \&\c
 662 \&; supported for compatibility with
 663 other tools.
 664
 665 .TP
 666 .B \-t
 667 Prints names of input files as \c
 668 .B ld\c
 669 \& processes them.
 670
 671 .TP
 672 .BI "-u " "sym"\c
 673 \&
 674 .I sym\c
 675 \&
 676 Forces \c
 677 .I sym\c
 678 \& to be entered in the output file as an undefined symbol.
 679 This may, for example, trigger linking of additional modules from
 680 standard libraries.  \c
 681 .B \-u\c
 682 \& may be repeated with different option
 683 arguments to enter additional undefined symbols.
 684
 685 .TP
 686 .B \-Ur
 687 For anything other than C++ programs, this option is equivalent to
 688 \c
 689 .B \-r\c
 690 \&: it generates relocatable output\(em\&i.e., an output file that can in
 691 turn serve as input to \c
 692 .B gld\c
 693 \&.  When linking C++ programs, \c
 694 .B \-Ur\c
 695 \&
 696 \c
 697 .I will\c
 698 \& resolve references to constructors, unlike \c
 699 .B \-r\c
 700 \&.
 701
 702 .TP
 703 .B \-v
 704 Display the version number for \c
 705 .B gld\c
 706 \&.
 707
 708 .TP
 709 .B \-X
 710 If \c
 711 .B \-s\c
 712 \& or \c
 713 .B \-S\c
 714 \& is also specified, delete only local symbols
 715 beginning with `\|\c
 716 .B L\c
 717 \|'.
 718
 719 .TP
 720 .B \-x
 721 If \c
 722 .B \-s\c
 723 \& or \c
 724 .B \-S\c
 725 \& is also specified, delete all local symbols,
 726 not just those beginning with `\|\c
 727 .B L\c
 728 \|'.
 729
 730 .PP
 731
 732 .SH ENVIRONMENT
 733 \c
 734 .B gld\c
 735 \& always consults two environment variables: \c
 736 .B GNUTARGET\c
 737 \&
 738 and \c
 739 .B LDEMULATION\c
 740 \&.  Depending on the setting of the latter, other
 741 environment variables may be used as well.
 742
 743 \c
 744 .B GNUTARGET\c
 745 \& determines the input-file object format if you don't
 746 use \c
 747 .B \-b\c
 748 \& (or its synonym \c
 749 .B \-format\c
 750 \&).  Its value should be one
 751 of the BFD names for an input format.  If there is no
 752 \c
 753 .B GNUTARGET\c
 754 \& in the environment, \c
 755 .B gld\c
 756 \& uses the natural format
 757 of the host. If \c
 758 .B GNUTARGET\c
 759 \& is set to \c
 760 .B default\c
 761 \& then BFD attempts to discover the
 762 input format by examining binary input files; this method often
 763 succeeds, but there are potential ambiguities, since there is no method
 764 of ensuring that the magic number used to flag object-file formats is
 765 unique.  However, the configuration procedure for BFD on each system
 766 places the conventional format for that system first in the search-list,
 767 so ambiguities are resolved in favor of convention.
 768
 769 \c
 770 .B LDEMULATION\c
 771 \& controls some aspects of \c
 772 .B gld\c
 773 \&'s dominant
 774 personality.  Although \c
 775 .B gld\c
 776 \& is flexible enough to permit its use
 777 in many contexts regardless of configuration, you can use this variable
 778 to make it act more like one or another older linker by default.
 779
 780 In particular, the value of \c
 781 .B LDEMULATION\c
 782 \& controls what default
 783 linker script is used (thereby controlling the default input and output
 784 formats; ; what default paths are searched for
 785 archive libraries; and in some cases whether additional linker script
 786 commands are available.
 787
 788 Here is the current set of emulations available:
 789
 790 .TP
 791 .B LDEMULATION=gld
 792 Emulate the older GNU linker.  When this emulation is selected, the
 793 default library search paths are
 794 .sp
 795 .br
 796 /lib
 797 .br
 798 /usr/lib
 799 .br
 800 /usr/local/lib/lib
 801 .br
 802 .sp
 803
 804 The default output format is set to \c
 805 .B a.out-generic-big\c
 806 \&, and the
 807 default machine is the system's configured BFD default.
 808
 809 .TP
 810 .B LDEMULATION=gld68k
 811 A variant of the \c
 812 .B gld\c
 813 \& emulation; only differs in specifically
 814 setting the default BFD machine as \c
 815 .B m68k\c
 816 \&.
 817
 818 .TP
 819 .B LDEMULATION=gld960
 820 Emulate the Intel port of the older \c
 821 .B gld\c
 822 \& for the i960
 823 architectures.  The default library search paths are taken from two
 824 other environment variables, \c
 825 .B G960LIB\c
 826 \& and \c
 827 .B G960BASE\c
 828 \&.  The
 829 default architecture is \c
 830 .B i960\c
 831 \&.  The default output format is set
 832 to \c
 833 .B b.out.big\c
 834 \&, and in fact the default output file name (if
 835 \c
 836 .B \-o\c
 837 \& is not specified) is \c
 838 .B b.out\c
 839 \&, to reflect this variant
 840 format, for this emulation.
 841
 842 This emulation can behave slightly differently depending on the setting
 843 of the \c
 844 .B gld\c
 845 \& compile-time switch \c
 846 .B GNU960\c
 847 \&.  If \c
 848 .B gld\c
 849 \& is
 850 compiled with \c
 851 .B GNU960\c
 852 \& defined, then an additional environment
 853 variable\(em\&\c
 854 .B GNUTARGET\c
 855 \&\(em\&is available; its value, if available,
 856 specifies some other default output format than \c
 857 .B b.out.big\c
 858 \&.
 859
 860 .TP
 861 .B LDEMULATION=gldm88kbcs
 862 Sets the output format to \c
 863 .B m88kbcs\c
 864 \& and the architecture to
 865 \c
 866 .B m88k\c
 867 \&.  Default library search paths are
 868 .sp
 869 .br
 870 /lib
 871 .br
 872 /usr/lib
 873 .br
 874 /usr/local/lib
 875 .br
 876 .sp
 877
 878 .TP
 879 .B LDEMULATION=lnk960
 880 Emulate the Intel linker \c
 881 .B lnk960\c
 882 \&.  The default output format is
 883 \c
 884 .B coff-Intel-big\c
 885 \&.  With this emulation, \c
 886 .B gld\c
 887 \&
 888 supports the additional script commands \c
 889 .B HLL\c
 890 \& and \c
 891 .B SYSLIB\c
 892 \& for
 893 specification of library archives.  This is the only emulation with
 894 extensive support for the \c
 895 .B \-A\c
 896 \& (architecture) command-line option.
 897 By default, the architecture \c
 898 .B CORE\c
 899 \& is assumed, but you can choose
 900 additional features from the i960 architecture family by using one of
 901 the following with \c
 902 .B \-A\c
 903 \& (or by using the \c
 904 .B OUTPUT_ARCH\c
 905 \& command
 906 from a script):
 907 .sp
 908 .br
 909 CORE
 910 .br
 911 KB
 912 .br
 913 SB
 914 .br
 915 MC
 916 .br
 917 XA
 918 .br
 919 CA
 920 .br
 921 KA
 922 .br
 923 SA
 924 .br
 925 .sp
 926
 927 The default libraries are chosen with some attention to the architecture
 928 selected; the core library `\|\c
 929 .B cg\c
 930 \|' is always included, but the library
 931 \c
 932 .B fpg\c
 933 \& is also used if you've specified any of the architectures
 934 \c
 935 .B KA\c
 936 \&, \c
 937 .B SA\c
 938 \&, or \c
 939 .B CA\c
 940 \&.
 941
 942 Like \c
 943 .B gld960\c
 944 \&, this emulation uses additional environment variables
 945 to set the default library search paths.  Also like \c
 946 .B gld960\c
 947 \&, the
 948 behavior of this emulation is slightly different depending on whether
 949 \c
 950 .B gld\c
 951 \& itself was compiled with \c
 952 .B GNU960\c
 953 \& defined.
 954
 955 If your \c
 956 .B gld\c
 957 \& was compiled with \c
 958 .B GNU960\c
 959 \& defined, the default
 960 paths are taken from all three of \c
 961 .B G960LIB\c
 962 \&, \c
 963 .B G960BASE\c
 964 \&, and
 965 \c
 966 .B I960BASE\c
 967 \&.  For the first two, paths you supply are automatically
 968 suffixed with `\|\c
 969 .B /lib/libcoff\c
 970 \|'; for the last, your path is
 971 automatically suffixed with `\|\c
 972 .B /lib\c
 973 \|'.
 974
 975 If your \c
 976 .B gld\c
 977 \& was \c
 978 .I not\c
 979 \& compiled with \c
 980 .B GNU960\c
 981 \& defined,
 982 the default paths are taken from \c
 983 .B I960BASE\c
 984 \&, and \c
 985 .B G960BASE\c
 986 \& is
 987 only consulted if \c
 988 .B I960BASE\c
 989 \& is undefined.  In this case
 990 \c
 991 .B G960LIB\c
 992 \& is not used at all.
 993
 994 .TP
 995 .B LDEMULATION=vanilla
 996 This is the least specific setting for \c
 997 .B gld\c
 998 \&.  You can set
 999 \c
1000 .B LDEMULATION=vanilla\c
1001 \& to disable emulation of other linkers.  This
1002 setting makes \c
1003 .B gld\c
1004 \& take the default machine from the BFD
1005 configuration on your system; \c
1006 .B a.out-generic-big\c
1007 \& is the default
1008 target.  No other defaults are specified.
1009
1010 .PP
1011
1012 .SH "SEE ALSO"
1013
1014 .BR objdump ( 1 )
1015 .br
1016 .br
1017 .RB "`\|" ld "\|' and `\|" binutils "\|'"
1018 entries in
1019 .B info\c
1020 .br
1021 .I
1022 gld: the GNU linker\c
1023 , Steve Chamberlain and Roland Pesch;
1024 .I
1025 The GNU Binary Utilities\c
1026 , Roland H. Pesch.
1027
1028 .SH COPYING
1029 Copyright (c) 1991, 1992 Free Software Foundation, Inc.
1030 .PP
1031 Permission is granted to make and distribute verbatim copies of
1032 this manual provided the copyright notice and this permission notice
1033 are preserved on all copies.
1034 .PP
1035 Permission is granted to copy and distribute modified versions of this
1036 manual under the conditions for verbatim copying, provided that the
1037 entire resulting derived work is distributed under the terms of a
1038 permission notice identical to this one.
1039 .PP
1040 Permission is granted to copy and distribute translations of this
1041 manual into another language, under the above conditions for modified
1042 versions, except that this permission notice may be included in
1043 translations approved by the Free Software Foundation instead of in
1044 the original English.