1 This file documents the installation of the GNU compiler. Copyright
2 (C) 1988, 1989, 1992, 1994, 1995 Free Software Foundation, Inc. You
3 may copy, distribute, and modify it freely as long as you preserve this
4 copyright notice and permission notice.
9 Here is the procedure for installing GNU CC on a Unix system. See
10 *Note VMS Install::, for VMS systems. In this section we assume you
11 compile in the same directory that contains the source files; see *Note
12 Other Dir::, to find out how to compile in a separate directory on Unix
15 You cannot install GNU C by itself on MSDOS; it will not compile
16 under any MSDOS compiler except itself. You need to get the complete
17 compilation package DJGPP, which includes binaries as well as sources,
18 and includes all the necessary compilation tools and libraries.
20 1. If you have built GNU CC previously in the same directory for a
21 different target machine, do `make distclean' to delete all files
22 that might be invalid. One of the files this deletes is
23 `Makefile'; if `make distclean' complains that `Makefile' does not
24 exist, it probably means that the directory is already suitably
27 2. On a System V release 4 system, make sure `/usr/bin' precedes
28 `/usr/ucb' in `PATH'. The `cc' command in `/usr/ucb' uses
29 libraries which have bugs.
31 3. Specify the host, build and target machine configurations. You do
32 this by running the file `configure'.
34 The "build" machine is the system which you are using, the "host"
35 machine is the system where you want to run the resulting compiler
36 (normally the build machine), and the "target" machine is the
37 system for which you want the compiler to generate code.
39 If you are building a compiler to produce code for the machine it
40 runs on (a native compiler), you normally do not need to specify
41 any operands to `configure'; it will try to guess the type of
42 machine you are on and use that as the build, host and target
43 machines. So you don't need to specify a configuration when
44 building a native compiler unless `configure' cannot figure out
45 what your configuration is or guesses wrong.
47 In those cases, specify the build machine's "configuration name"
48 with the `--build' option; the host and target will default to be
49 the same as the build machine. (If you are building a
50 cross-compiler, see *Note Cross-Compiler::.)
54 ./configure --build=sparc-sun-sunos4.1
56 A configuration name may be canonical or it may be more or less
59 A canonical configuration name has three parts, separated by
60 dashes. It looks like this: `CPU-COMPANY-SYSTEM'. (The three
61 parts may themselves contain dashes; `configure' can figure out
62 which dashes serve which purpose.) For example,
63 `m68k-sun-sunos4.1' specifies a Sun 3.
65 You can also replace parts of the configuration by nicknames or
66 aliases. For example, `sun3' stands for `m68k-sun', so
67 `sun3-sunos4.1' is another way to specify a Sun 3. You can also
68 use simply `sun3-sunos', since the version of SunOS is assumed by
69 default to be version 4. `sun3-bsd' also works, since `configure'
70 knows that the only BSD variant on a Sun 3 is SunOS.
72 You can specify a version number after any of the system types,
73 and some of the CPU types. In most cases, the version is
74 irrelevant, and will be ignored. So you might as well specify the
75 version if you know it.
77 See *Note Configurations::, for a list of supported configuration
78 names and notes on many of the configurations. You should check
79 the notes in that section before proceeding any further with the
80 installation of GNU CC.
82 There are four additional options you can specify independently to
83 describe variant hardware and software configurations. These are
84 `--with-gnu-as', `--with-gnu-ld', `--with-stabs' and `--nfp'.
87 If you will use GNU CC with the GNU assembler (GAS), you
88 should declare this by using the `--with-gnu-as' option when
91 Using this option does not install GAS. It only modifies the
92 output of GNU CC to work with GAS. Building and installing
95 Conversely, if you *do not* wish to use GAS and do not specify
96 `--with-gnu-as' when building GNU CC, it is up to you to make
97 sure that GAS is not installed. GNU CC searches for a
98 program named `as' in various directories; if the program it
99 finds is GAS, then it runs GAS. If you are not sure where
100 GNU CC finds the assembler it is using, try specifying `-v'
103 The systems where it makes a difference whether you use GAS
105 `hppa1.0-ANY-ANY', `hppa1.1-ANY-ANY', `i386-ANY-sysv',
107 `i860-ANY-bsd', `m68k-bull-sysv', `m68k-hp-hpux',
109 `m68k-altos-sysv', `m68000-hp-hpux', `m68000-att-sysv',
110 `ANY-lynx-lynxos', and `mips-ANY'). On any other system,
111 `--with-gnu-as' has no effect.
113 On the systems listed above (except for the HP-PA, for ISC on
114 the 386, and for `mips-sgi-irix5.*'), if you use GAS, you
115 should also use the GNU linker (and specify `--with-gnu-ld').
118 Specify the option `--with-gnu-ld' if you plan to use the GNU
121 This option does not cause the GNU linker to be installed; it
122 just modifies the behavior of GNU CC to work with the GNU
123 linker. Specifically, it inhibits the installation of
124 `collect2', a program which otherwise serves as a front-end
125 for the system's linker on most configurations.
128 On MIPS based systems and on Alphas, you must specify whether
129 you want GNU CC to create the normal ECOFF debugging format,
130 or to use BSD-style stabs passed through the ECOFF symbol
131 table. The normal ECOFF debug format cannot fully handle
132 languages other than C. BSD stabs format can handle other
133 languages, but it only works with the GNU debugger GDB.
135 Normally, GNU CC uses the ECOFF debugging format by default;
136 if you prefer BSD stabs, specify `--with-stabs' when you
139 No matter which default you choose when you configure GNU CC,
140 the user can use the `-gcoff' and `-gstabs+' options to
141 specify explicitly the debug format for a particular
144 `--with-stabs' is meaningful on the ISC system on the 386,
145 also, if `--with-gas' is used. It selects use of stabs
146 debugging information embedded in COFF output. This kind of
147 debugging information supports C++ well; ordinary COFF
148 debugging information does not.
150 `--with-stabs' is also meaningful on 386 systems running
151 SVR4. It selects use of stabs debugging information embedded
152 in ELF output. The C++ compiler currently (2.6.0) does not
153 support the DWARF debugging information normally used on 386
154 SVR4 platforms; stabs provide a workable alternative. This
155 requires gas and gdb, as the normal SVR4 tools can not
156 generate or interpret stabs.
159 On certain systems, you must specify whether the machine has
160 a floating point unit. These systems include
161 `m68k-sun-sunosN' and `m68k-isi-bsd'. On any other system,
162 `--nfp' currently has no effect, though perhaps there are
163 other systems where it could usefully make a difference.
165 The `configure' script searches subdirectories of the source
166 directory for other compilers that are to be integrated into GNU
167 CC. The GNU compiler for C++, called G++ is in a subdirectory
168 named `cp'. `configure' inserts rules into `Makefile' to build
169 all of those compilers.
171 Here we spell out what files will be set up by `configure'.
172 Normally you need not be concerned with these files.
174 * A file named `config.h' is created that contains a `#include'
175 of the top-level config file for the machine you will run the
176 compiler on (*note The Configuration File:
177 (gcc.info)Config.). This file is responsible for defining
178 information about the host machine. It includes `tm.h'.
180 The top-level config file is located in the subdirectory
181 `config'. Its name is always `xm-SOMETHING.h'; usually
182 `xm-MACHINE.h', but there are some exceptions.
184 If your system does not support symbolic links, you might
185 want to set up `config.h' to contain a `#include' command
186 which refers to the appropriate file.
188 * A file named `tconfig.h' is created which includes the
189 top-level config file for your target machine. This is used
190 for compiling certain programs to run on that machine.
192 * A file named `tm.h' is created which includes the
193 machine-description macro file for your target machine. It
194 should be in the subdirectory `config' and its name is often
197 * The command file `configure' also constructs the file
198 `Makefile' by adding some text to the template file
199 `Makefile.in'. The additional text comes from files in the
200 `config' directory, named `t-TARGET' and `x-HOST'. If these
201 files do not exist, it means nothing needs to be added for a
202 given target or host.
204 4. The standard directory for installing GNU CC is `/usr/local/lib'.
205 If you want to install its files somewhere else, specify
206 `--prefix=DIR' when you run `configure'. Here DIR is a directory
207 name to use instead of `/usr/local' for all purposes with one
208 exception: the directory `/usr/local/include' is searched for
209 header files no matter where you install the compiler. To override
210 this name, use the `--local-prefix' option below.
212 5. Specify `--local-prefix=DIR' if you want the compiler to search
213 directory `DIR/include' for locally installed header files
214 *instead* of `/usr/local/include'.
216 You should specify `--local-prefix' *only* if your site has a
217 different convention (not `/usr/local') for where to put
220 *Do not* specify `/usr' as the `--local-prefix'! The directory
221 you use for `--local-prefix' *must not* contain any of the
222 system's standard header files. If it did contain them, certain
223 programs would be miscompiled (including GNU Emacs, on certain
224 targets), because this would override and nullify the header file
225 corrections made by the `fixincludes' script.
227 6. Make sure the Bison parser generator is installed. (This is
228 unnecessary if the Bison output files `c-parse.c' and `cexp.c' are
229 more recent than `c-parse.y' and `cexp.y' and you do not plan to
230 change the `.y' files.)
232 Bison versions older than Sept 8, 1988 will produce incorrect
233 output for `c-parse.c'.
235 7. If you have chosen a configuration for GNU CC which requires other
236 GNU tools (such as GAS or the GNU linker) instead of the standard
237 system tools, install the required tools in the build directory
238 under the names `as', `ld' or whatever is appropriate. This will
239 enable the compiler to find the proper tools for compilation of
240 the program `enquire'.
242 Alternatively, you can do subsequent compilation using a value of
243 the `PATH' environment variable such that the necessary GNU tools
244 come before the standard system tools.
246 8. Build the compiler. Just type `make LANGUAGES=c' in the compiler
249 `LANGUAGES=c' specifies that only the C compiler should be
250 compiled. The makefile normally builds compilers for all the
251 supported languages; currently, C, C++ and Objective C. However,
252 C is the only language that is sure to work when you build with
253 other non-GNU C compilers. In addition, building anything but C
254 at this stage is a waste of time.
256 In general, you can specify the languages to build by typing the
257 argument `LANGUAGES="LIST"', where LIST is one or more words from
258 the list `c', `c++', and `objective-c'. If you have any
259 additional GNU compilers as subdirectories of the GNU CC source
260 directory, you may also specify their names in this list.
262 Ignore any warnings you may see about "statement not reached" in
263 `insn-emit.c'; they are normal. Also, warnings about "unknown
264 escape sequence" are normal in `genopinit.c' and perhaps some
265 other files. Likewise, you should ignore warnings about "constant
266 is so large that it is unsigned" in `insn-emit.c' and
267 `insn-recog.c' and a warning about a comparison always being zero
268 in `enquire.o'. Any other compilation errors may represent bugs in
269 the port to your machine or operating system, and should be
270 investigated and reported.
272 Some commercial compilers fail to compile GNU CC because they have
273 bugs or limitations. For example, the Microsoft compiler is said
274 to run out of macro space. Some Ultrix compilers run out of
275 expression space; then you need to break up the statement where
278 9. If you are building a cross-compiler, stop here. *Note
281 10. Move the first-stage object files and executables into a
282 subdirectory with this command:
286 The files are moved into a subdirectory named `stage1'. Once
287 installation is complete, you may wish to delete these files with
290 11. If you have chosen a configuration for GNU CC which requires other
291 GNU tools (such as GAS or the GNU linker) instead of the standard
292 system tools, install the required tools in the `stage1'
293 subdirectory under the names `as', `ld' or whatever is
294 appropriate. This will enable the stage 1 compiler to find the
295 proper tools in the following stage.
297 Alternatively, you can do subsequent compilation using a value of
298 the `PATH' environment variable such that the necessary GNU tools
299 come before the standard system tools.
301 12. Recompile the compiler with itself, with this command:
303 make CC="stage1/xgcc -Bstage1/" CFLAGS="-g -O2"
305 This is called making the stage 2 compiler.
307 The command shown above builds compilers for all the supported
308 languages. If you don't want them all, you can specify the
309 languages to build by typing the argument `LANGUAGES="LIST"'. LIST
310 should contain one or more words from the list `c', `c++',
311 `objective-c', and `proto'. Separate the words with spaces.
312 `proto' stands for the programs `protoize' and `unprotoize'; they
313 are not a separate language, but you use `LANGUAGES' to enable or
314 disable their installation.
316 If you are going to build the stage 3 compiler, then you might
317 want to build only the C language in stage 2.
319 Once you have built the stage 2 compiler, if you are short of disk
320 space, you can delete the subdirectory `stage1'.
322 On a 68000 or 68020 system lacking floating point hardware, unless
323 you have selected a `tm.h' file that expects by default that there
324 is no such hardware, do this instead:
326 make CC="stage1/xgcc -Bstage1/" CFLAGS="-g -O2 -msoft-float"
328 13. If you wish to test the compiler by compiling it with itself one
329 more time, install any other necessary GNU tools (such as GAS or
330 the GNU linker) in the `stage2' subdirectory as you did in the
331 `stage1' subdirectory, then do this:
334 make CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O2"
336 This is called making the stage 3 compiler. Aside from the `-B'
337 option, the compiler options should be the same as when you made
338 the stage 2 compiler. But the `LANGUAGES' option need not be the
339 same. The command shown above builds compilers for all the
340 supported languages; if you don't want them all, you can specify
341 the languages to build by typing the argument `LANGUAGES="LIST"',
344 If you do not have to install any additional GNU tools, you may
347 make bootstrap LANGUAGES=LANGUAGE-LIST BOOT_CFLAGS=OPTION-LIST
349 instead of making `stage1', `stage2', and performing the two
352 14. Then compare the latest object files with the stage 2 object
353 files--they ought to be identical, aside from time stamps (if any).
355 On some systems, meaningful comparison of object files is
356 impossible; they always appear "different." This is currently
357 true on Solaris and some systems that use ELF object file format.
358 On some versions of Irix on SGI machines and DEC Unix (OSF/1) on
359 Alpha systems, you will not be able to compare the files without
360 specifying `-save-temps'; see the description of individual
361 systems above to see if you get comparison failures. You may have
362 similar problems on other systems.
364 Use this command to compare the files:
368 This will mention any object files that differ between stage 2 and
369 stage 3. Any difference, no matter how innocuous, indicates that
370 the stage 2 compiler has compiled GNU CC incorrectly, and is
371 therefore a potentially serious bug which you should investigate
374 If your system does not put time stamps in the object files, then
375 this is a faster way to compare them (using the Bourne shell):
378 cmp $file stage2/$file
381 If you have built the compiler with the `-mno-mips-tfile' option on
382 MIPS machines, you will not be able to compare the files.
384 15. Install the compiler driver, the compiler's passes and run-time
385 support with `make install'. Use the same value for `CC',
386 `CFLAGS' and `LANGUAGES' that you used when compiling the files
387 that are being installed. One reason this is necessary is that
388 some versions of Make have bugs and recompile files gratuitously
389 when you do this step. If you use the same variable values, those
390 files will be recompiled properly.
392 For example, if you have built the stage 2 compiler, you can use
393 the following command:
395 make install CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O" LANGUAGES="LIST"
397 This copies the files `cc1', `cpp' and `libgcc.a' to files `cc1',
398 `cpp' and `libgcc.a' in the directory
399 `/usr/local/lib/gcc-lib/TARGET/VERSION', which is where the
400 compiler driver program looks for them. Here TARGET is the target
401 machine type specified when you ran `configure', and VERSION is
402 the version number of GNU CC. This naming scheme permits various
403 versions and/or cross-compilers to coexist.
405 This also copies the driver program `xgcc' into
406 `/usr/local/bin/gcc', so that it appears in typical execution
409 On some systems, this command causes recompilation of some files.
410 This is usually due to bugs in `make'. You should either ignore
411 this problem, or use GNU Make.
413 *Warning: there is a bug in `alloca' in the Sun library. To avoid
414 this bug, be sure to install the executables of GNU CC that were
415 compiled by GNU CC. (That is, the executables from stage 2 or 3,
416 not stage 1.) They use `alloca' as a built-in function and never
417 the one in the library.*
419 (It is usually better to install GNU CC executables from stage 2
420 or 3, since they usually run faster than the ones compiled with
421 some other compiler.)
423 16. If you're going to use C++, it's likely that you need to also
424 install the libg++ distribution. It should be available from the
425 same place where you got the GNU C distribution. Just as GNU C
426 does not distribute a C runtime library, it also does not include
427 a C++ run-time library. All I/O functionality, special class
428 libraries, etc., are available in the libg++ distribution.
430 Configurations Supported by GNU CC
431 ==================================
433 Here are the possible CPU types:
435 1750a, a29k, alpha, arm, cN, clipper, dsp16xx, elxsi, h8300,
436 hppa1.0, hppa1.1, i370, i386, i486, i586, i860, i960, m68000, m68k,
437 m88k, mips, mipsel, mips64, mips64el, ns32k, powerpc, powerpcle,
438 pyramid, romp, rs6000, sh, sparc, sparclite, sparc64, vax, we32k.
440 Here are the recognized company names. As you can see, customary
441 abbreviations are used rather than the longer official names.
443 acorn, alliant, altos, apollo, att, bull, cbm, convergent, convex,
444 crds, dec, dg, dolphin, elxsi, encore, harris, hitachi, hp, ibm,
445 intergraph, isi, mips, motorola, ncr, next, ns, omron, plexus,
446 sequent, sgi, sony, sun, tti, unicom, wrs.
448 The company name is meaningful only to disambiguate when the rest of
449 the information supplied is insufficient. You can omit it, writing
450 just `CPU-SYSTEM', if it is not needed. For example, `vax-ultrix4.2'
451 is equivalent to `vax-dec-ultrix4.2'.
453 Here is a list of system types:
455 386bsd, aix, acis, amigados, aos, aout, bosx, bsd, clix, coff,
456 ctix, cxux, dgux, dynix, ebmon, ecoff, elf, esix, freebsd, hms,
457 genix, gnu, gnu/linux, hiux, hpux, iris, irix, isc, luna, lynxos,
458 mach, minix, msdos, mvs, netbsd, newsos, nindy, ns, osf, osfrose,
459 ptx, riscix, riscos, rtu, sco, sim, solaris, sunos, sym, sysv,
460 udi, ultrix, unicos, uniplus, unos, vms, vsta, vxworks, winnt,
463 You can omit the system type; then `configure' guesses the operating
464 system from the CPU and company.
466 You can add a version number to the system type; this may or may not
467 make a difference. For example, you can write `bsd4.3' or `bsd4.4' to
468 distinguish versions of BSD. In practice, the version number is most
469 needed for `sysv3' and `sysv4', which are often treated differently.
471 If you specify an impossible combination such as `i860-dg-vms', then
472 you may get an error message from `configure', or it may ignore part of
473 the information and do the best it can with the rest. `configure'
474 always prints the canonical name for the alternative that it used. GNU
475 CC does not support all possible alternatives.
477 Often a particular model of machine has a name. Many machine names
478 are recognized as aliases for CPU/company combinations. Thus, the
479 machine name `sun3', mentioned above, is an alias for `m68k-sun'.
480 Sometimes we accept a company name as a machine name, when the name is
481 popularly used for a particular machine. Here is a table of the known
484 3300, 3b1, 3bN, 7300, altos3068, altos, apollo68, att-7300,
485 balance, convex-cN, crds, decstation-3100, decstation, delta,
486 encore, fx2800, gmicro, hp7NN, hp8NN, hp9k2NN, hp9k3NN, hp9k7NN,
487 hp9k8NN, iris4d, iris, isi68, m3230, magnum, merlin, miniframe,
488 mmax, news-3600, news800, news, next, pbd, pc532, pmax, powerpc,
489 powerpcle, ps2, risc-news, rtpc, sun2, sun386i, sun386, sun3,
490 sun4, symmetry, tower-32, tower.
492 Remember that a machine name specifies both the cpu type and the company
493 name. If you want to install your own homemade configuration files,
494 you can use `local' as the company name to access them. If you use
495 configuration `CPU-local', the configuration name without the cpu prefix
496 is used to form the configuration file names.
498 Thus, if you specify `m68k-local', configuration uses files
499 `m68k.md', `local.h', `m68k.c', `xm-local.h', `t-local', and `x-local',
500 all in the directory `config/m68k'.
502 Here is a list of configurations that have special treatment or
503 special things you must know:
506 MIL-STD-1750A processors.
508 Starting with GCC 2.6.1, the MIL-STD-1750A cross configuration no
509 longer supports the Tektronix Assembler, but instead produces
510 output for `as1750', an assembler/linker available under the GNU
511 Public License for the 1750A. Contact *kellogg@space.otn.dasa.de*
512 for more details on obtaining `as1750'. A similarly licensed
513 simulator for the 1750A is available from same address.
515 You should ignore a fatal error during the building of libgcc
516 (libgcc is not yet implemented for the 1750A.)
518 The `as1750' assembler requires the file `ms1750.inc', which is
519 found in the directory `config/1750a'.
521 GNU CC produced the same sections as the Fairchild F9450 C
525 The program code section.
528 The read/write (RAM) data section.
531 The read-only (ROM) constants section.
534 Initialization section (code to copy KREL to SREL).
536 The smallest addressable unit is 16 bits (BITS_PER_UNIT is 16).
537 This means that type `char' is represented with a 16-bit word per
538 character. The 1750A's "Load/Store Upper/Lower Byte" instructions
539 are not used by GNU CC.
542 Systems using processors that implement the DEC Alpha architecture
543 and are running the DEC Unix (OSF/1) operating system, for example
544 the DEC Alpha AXP systems. (VMS on the Alpha is not currently
545 supported by GNU CC.)
547 GNU CC writes a `.verstamp' directive to the assembler output file
548 unless it is built as a cross-compiler. It gets the version to
549 use from the system header file `/usr/include/stamp.h'. If you
550 install a new version of DEC Unix, you should rebuild GCC to pick
551 up the new version stamp.
553 Note that since the Alpha is a 64-bit architecture,
554 cross-compilers from 32-bit machines will not generate code as
555 efficient as that generated when the compiler is running on a
556 64-bit machine because many optimizations that depend on being
557 able to represent a word on the target in an integral value on the
558 host cannot be performed. Building cross-compilers on the Alpha
559 for 32-bit machines has only been tested in a few cases and may
562 `make compare' may fail on old versions of DEC Unix unless you add
563 `-save-temps' to `CFLAGS'. On these systems, the name of the
564 assembler input file is stored in the object file, and that makes
565 comparison fail if it differs between the `stage1' and `stage2'
566 compilations. The option `-save-temps' forces a fixed name to be
567 used for the assembler input file, instead of a randomly chosen
568 name in `/tmp'. Do not add `-save-temps' unless the comparisons
569 fail without that option. If you add `-save-temps', you will have
570 to manually delete the `.i' and `.s' files after each series of
573 GNU CC now supports both the native (ECOFF) debugging format used
574 by DBX and GDB and an encapsulated STABS format for use only with
575 GDB. See the discussion of the `--with-stabs' option of
576 `configure' above for more information on these formats and how to
579 There is a bug in DEC's assembler that produces incorrect line
580 numbers for ECOFF format when the `.align' directive is used. To
581 work around this problem, GNU CC will not emit such alignment
582 directives while writing ECOFF format debugging information even
583 if optimization is being performed. Unfortunately, this has the
584 very undesirable side-effect that code addresses when `-O' is
585 specified are different depending on whether or not `-g' is also
588 To avoid this behavior, specify `-gstabs+' and use GDB instead of
589 DBX. DEC is now aware of this problem with the assembler and
590 hopes to provide a fix shortly.
593 Advanced RISC Machines ARM-family processors. These are often
594 used in embedded applications. There are no standard Unix
595 configurations. This configuration corresponds to the basic
596 instruction sequences and will produce a.out format object modules.
598 You may need to make a variant of the file `arm.h' for your
599 particular configuration.
602 The ARM2 or ARM3 processor running RISC iX, Acorn's port of BSD
603 Unix. If you are running a version of RISC iX prior to 1.2 then
604 you must specify the version number during configuration. Note
605 that the assembler shipped with RISC iX does not support stabs
606 debugging information; a new version of the assembler, with stabs
607 support included, is now available from Acorn.
610 AMD Am29k-family processors. These are normally used in embedded
611 applications. There are no standard Unix configurations. This
612 configuration corresponds to AMD's standard calling sequence and
613 binary interface and is compatible with other 29k tools.
615 You may need to make a variant of the file `a29k.h' for your
616 particular configuration.
619 AMD Am29050 used in a system running a variant of BSD Unix.
622 DECstations can support three different personalities: Ultrix, DEC
623 OSF/1, and OSF/rose. To configure GCC for these platforms use the
624 following configurations:
627 Ultrix configuration.
630 Dec's version of OSF/1.
633 Open Software Foundation reference port of OSF/1 which uses
634 the OSF/rose object file format instead of ECOFF. Normally,
635 you would not select this configuration.
637 The MIPS C compiler needs to be told to increase its table size
638 for switch statements with the `-Wf,-XNg1500' option in order to
639 compile `cp/parse.c'. If you use the `-O2' optimization option,
640 you also need to use `-Olimit 3000'. Both of these options are
641 automatically generated in the `Makefile' that the shell script
642 `configure' builds. If you override the `CC' make variable and
643 use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
647 The Elxsi's C compiler has known limitations that prevent it from
648 compiling GNU C. Please contact `mrs@cygnus.com' for more details.
651 A port to the AT&T DSP1610 family of processors.
654 The calling convention and structure layout has changed in release
655 2.6. All code must be recompiled. The calling convention now
656 passes the first three arguments in function calls in registers.
657 Structures are no longer a multiple of 2 bytes.
660 There are two variants of this CPU, called 1.0 and 1.1, which have
661 different machine descriptions. You must use the right one for
662 your machine. All 7NN machines and 8N7 machines use 1.1, while
663 all other 8NN machines use 1.0.
665 The easiest way to handle this problem is to use `configure hpNNN'
666 or `configure hpNNN-hpux', where NNN is the model number of the
667 machine. Then `configure' will figure out if the machine is a 1.0
668 or 1.1. Use `uname -a' to find out the model number of your
671 `-g' does not work on HP-UX, since that system uses a peculiar
672 debugging format which GNU CC does not know about. However, `-g'
673 will work if you also use GAS and GDB in conjunction with GCC. We
674 highly recommend using GAS for all HP-PA configurations.
676 You should be using GAS-2.3 (or later) along with GDB-4.12 (or
677 later). These can be retrieved from all the traditional GNU ftp
680 Build GAS and install the resulting binary as:
682 /usr/local/lib/gcc-lib/CONFIGURATION/GCCVERSION/as
684 where CONFIGURATION is the configuration name (perhaps
685 `hpNNN-hpux') and GCCVERSION is the GNU CC version number. Do
686 this *before* starting the build process, otherwise you will get
687 errors from the HPUX assembler while building `libgcc2.a'. The
692 will create the necessary directory hierarchy so you can install
693 GAS before building GCC.
695 To enable debugging, configure GNU CC with the `--with-gnu-as'
696 option before building.
698 It has been reported that GNU CC produces invalid assembly code for
699 1.1 machines running HP-UX 8.02 when using the HP assembler.
700 Typically the errors look like this:
701 as: bug.s @line#15 [err#1060]
702 Argument 0 or 2 in FARG upper
703 - lookahead = ARGW1=FR,RTNVAL=GR
704 as: foo.s @line#28 [err#1060]
705 Argument 0 or 2 in FARG upper
706 - lookahead = ARGW1=FR
708 You can check the version of HP-UX you are running by executing
709 the command `uname -r'. If you are indeed running HP-UX 8.02 on
710 a PA and using the HP assembler then configure GCC with
714 This port is very preliminary and has many known bugs. We hope to
715 have a higher-quality port for this machine soon.
718 Use this configuration to generate a.out binaries on Linux if you
719 do not have gas/binutils version 2.5.2 or later installed. This is
720 an obsolete configuration.
723 Use this configuration to generate a.out binaries on Linux. This
724 configuration is being superseded. You must use gas/binutils
725 version 2.5.2 or later.
728 Use this configuration to generate ELF binaries on Linux. You must
729 use gas/binutils version 2.5.2 or later.
732 Compilation with RCC is recommended. Also, it may be a good idea
733 to link with GNU malloc instead of the malloc that comes with the
737 Use this configuration for SCO release 3.2 version 4.
740 It may be a good idea to link with GNU malloc instead of the
741 malloc that comes with the system.
743 In ISC version 4.1, `sed' core dumps when building `deduced.h'.
744 Use the version of `sed' from version 4.0.
747 It may be good idea to link with GNU malloc instead of the malloc
748 that comes with the system.
751 You need to use GAS version 2.1 or later, and and LD from GNU
752 binutils version 2.2 or later.
755 Go to the Berkeley universe before compiling. In addition, you
756 probably need to create a file named `string.h' containing just
757 one line: `#include <strings.h>'.
760 Sequent DYNIX/ptx 1.x.
763 Sequent DYNIX/ptx 2.x.
766 You may find that you need another version of GNU CC to begin
767 bootstrapping with, since the current version when built with the
768 system's own compiler seems to get an infinite loop compiling part
769 of `libgcc2.c'. GNU CC version 2 compiled with GNU CC (any
770 version) seems not to have this problem.
772 See *Note Sun Install::, for information on installing GNU CC on
775 `i[345]86-*-winnt3.5'
776 This version requires a GAS that has not let been released. Until
777 it is, you can get a prebuilt binary version via anonymous ftp from
778 `cs.washington.edu:pub/gnat' or `cs.nyu.edu:pub/gnat'. You must
779 also use the Microsoft header files from the Windows NT 3.5 SDK.
780 Find these on the CDROM in the `/mstools/h' directory dated
781 9/4/94. You must use a fixed version of Microsoft linker made
782 especially for NT 3.5, which is also is available on the NT 3.5
783 SDK CDROM. If you do not have this linker, can you also use the
784 linker from Visual C/C++ 1.0 or 2.0.
786 Installing GNU CC for NT builds a wrapper linker, called `ld.exe',
787 which mimics the behaviour of Unix `ld' in the specification of
788 libraries (`-L' and `-l'). `ld.exe' looks for both Unix and
789 Microsoft named libraries. For example, if you specify `-lfoo',
790 `ld.exe' will look first for `libfoo.a' and then for `foo.lib'.
792 You may install GNU CC for Windows NT in one of two ways,
793 depending on whether or not you have a Unix-like shell and various
796 1. If you do not have a Unix-like shell and few Unix-like
797 utilities, you will use a DOS style batch script called
798 `configure.bat'. Invoke it as `configure winnt' from an
799 MSDOS console window or from the program manager dialog box.
800 `configure.bat' assumes you have already installed and have
801 in your path a Unix-like `sed' program which is used to
802 create a working `Makefile' from `Makefile.in'.
804 `Makefile' uses the Microsoft Nmake program maintenance
805 utility and the Visual C/C++ V8.00 compiler to build GNU CC.
806 You need only have the utilities `sed' and `touch' to use
807 this installation method, which only automatically builds the
808 compiler itself. You must then examine what `fixinc.winnt'
809 does, edit the header files by hand and build `libgcc.a'
812 2. The second type of installation assumes you are running a
813 Unix-like shell, have a complete suite of Unix-like utilities
814 in your path, and have a previous version of GNU CC already
815 installed, either through building it via the above
816 installation method or acquiring a pre-built binary. In this
817 case, use the `configure' script in the normal fashion.
820 This is the Paragon. If you have version 1.0 of the operating
821 system, you need to take special steps to build GNU CC due to
822 peculiarities of the system. Newer system versions have no
823 problem. See the section `Installation Problems' in the GNU CC
827 LynxOS 2.2 and earlier comes with GNU CC 1.x already installed as
828 `/bin/gcc'. You should compile with this instead of `/bin/cc'.
829 You can tell GNU CC to use the GNU assembler and linker, by
830 specifying `--with-gnu-as --with-gnu-ld' when configuring. These
831 will produce COFF format object files and executables; otherwise
832 GNU CC will use the installed tools, which produce a.out format
836 HP 9000 series 200 running BSD. Note that the C compiler that
837 comes with this system cannot compile GNU CC; contact
838 `law@cs.utah.edu' to get binaries of GNU CC for bootstrapping.
841 Altos 3068. You must use the GNU assembler, linker and debugger.
842 Also, you must fix a kernel bug. Details in the file
846 AT&T 3b1, a.k.a. 7300 PC. Special procedures are needed to
847 compile GNU CC with this machine's standard C compiler, due to
848 bugs in that compiler. You can bootstrap it more easily with
849 previous versions of GNU CC if you have them.
851 Installing GNU CC on the 3b1 is difficult if you do not already
852 have GNU CC running, due to bugs in the installed C compiler.
853 However, the following procedure might work. We are unable to
856 1. Comment out the `#include "config.h"' line on line 37 of
857 `cccp.c' and do `make cpp'. This makes a preliminary version
860 2. Save the old `/lib/cpp' and copy the preliminary GNU cpp to
863 3. Undo your change in `cccp.c', or reinstall the original
864 version, and do `make cpp' again.
866 4. Copy this final version of GNU cpp into `/lib/cpp'.
868 5. Replace every occurrence of `obstack_free' in the file
869 `tree.c' with `_obstack_free'.
871 6. Run `make' to get the first-stage GNU CC.
873 7. Reinstall the original version of `/lib/cpp'.
875 8. Now you can compile GNU CC with itself and install it in the
879 Bull DPX/2 series 200 and 300 with BOS-2.00.45 up to BOS-2.01. GNU
880 CC works either with native assembler or GNU assembler. You can use
881 GNU assembler with native coff generation by providing
882 `--with-gnu-as' to the configure script or use GNU assembler with
883 dbx-in-coff encapsulation by providing `--with-gnu-as --stabs'.
884 For any problem with native assembler or for availability of the
885 DPX/2 port of GAS, contact `F.Pierresteguy@frcl.bull.fr'.
888 Use `configure unos' for building on Unos.
890 The Unos assembler is named `casm' instead of `as'. For some
891 strange reason linking `/bin/as' to `/bin/casm' changes the
892 behavior, and does not work. So, when installing GNU CC, you
893 should install the following script as `as' in the subdirectory
894 where the passes of GCC are installed:
899 The default Unos library is named `libunos.a' instead of `libc.a'.
900 To allow GNU CC to function, either change all references to
901 `-lc' in `gcc.c' to `-lunos' or link `/lib/libc.a' to
904 When compiling GNU CC with the standard compiler, to overcome bugs
905 in the support of `alloca', do not use `-O' when making stage 2.
906 Then use the stage 2 compiler with `-O' to make the stage 3
907 compiler. This compiler will have the same characteristics as the
908 usual stage 2 compiler on other systems. Use it to make a stage 4
909 compiler and compare that with stage 3 to verify proper
912 (Perhaps simply defining `ALLOCA' in `x-crds' as described in the
913 comments there will make the above paragraph superfluous. Please
914 inform us of whether this works.)
916 Unos uses memory segmentation instead of demand paging, so you
917 will need a lot of memory. 5 Mb is barely enough if no other
918 tasks are running. If linking `cc1' fails, try putting the object
919 files into a library and linking from that library.
922 HP 9000 series 300 or 400 running HP-UX. HP-UX version 8.0 has a
923 bug in the assembler that prevents compilation of GNU CC. To fix
924 it, get patch PHCO_4484 from HP.
926 In addition, if you wish to use gas `--with-gnu-as' you must use
927 gas version 2.1 or later, and you must use the GNU linker version
928 2.1 or later. Earlier versions of gas relied upon a program which
929 converted the gas output into the native HP/UX format, but that
930 program has not been kept up to date. gdb does not understand
931 that native HP/UX format, so you must use gas if you wish to use
935 Sun 3. We do not provide a configuration file to use the Sun FPA
936 by default, because programs that establish signal handlers for
937 floating point traps inherently cannot work with the FPA.
939 See *Note Sun Install::, for information on installing GNU CC on
943 Motorola m88k running the AT&T/Unisoft/Motorola V.3 reference port.
944 These systems tend to use the Green Hills C, revision 1.8.5, as the
945 standard C compiler. There are apparently bugs in this compiler
946 that result in object files differences between stage 2 and stage
947 3. If this happens, make the stage 4 compiler and compare it to
948 the stage 3 compiler. If the stage 3 and stage 4 object files are
949 identical, this suggests you encountered a problem with the
950 standard C compiler; the stage 3 and 4 compilers may be usable.
952 It is best, however, to use an older version of GNU CC for
953 bootstrapping if you have one.
956 Motorola m88k running DG/UX. To build 88open BCS native or cross
957 compilers on DG/UX, specify the configuration name as
958 `m88k-*-dguxbcs' and build in the 88open BCS software development
959 environment. To build ELF native or cross compilers on DG/UX,
960 specify `m88k-*-dgux' and build in the DG/UX ELF development
961 environment. You set the software development environment by
962 issuing `sde-target' command and specifying either `m88kbcs' or
963 `m88kdguxelf' as the operand.
965 If you do not specify a configuration name, `configure' guesses the
966 configuration based on the current software development
969 `m88k-tektronix-sysv3'
970 Tektronix XD88 running UTekV 3.2e. Do not turn on optimization
971 while building stage1 if you bootstrap with the buggy Green Hills
972 compiler. Also, The bundled LAI System V NFS is buggy so if you
973 build in an NFS mounted directory, start from a fresh reboot, or
974 avoid NFS all together. Otherwise you may have trouble getting
975 clean comparisons between stages.
978 MIPS machines running the MIPS operating system in BSD mode. It's
979 possible that some old versions of the system lack the functions
980 `memcpy', `memcmp', and `memset'. If your system lacks these, you
981 must remove or undo the definition of `TARGET_MEM_FUNCTIONS' in
984 The MIPS C compiler needs to be told to increase its table size
985 for switch statements with the `-Wf,-XNg1500' option in order to
986 compile `cp/parse.c'. If you use the `-O2' optimization option,
987 you also need to use `-Olimit 3000'. Both of these options are
988 automatically generated in the `Makefile' that the shell script
989 `configure' builds. If you override the `CC' make variable and
990 use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
994 The MIPS C compiler needs to be told to increase its table size
995 for switch statements with the `-Wf,-XNg1500' option in order to
996 compile `cp/parse.c'. If you use the `-O2' optimization option,
997 you also need to use `-Olimit 3000'. Both of these options are
998 automatically generated in the `Makefile' that the shell script
999 `configure' builds. If you override the `CC' make variable and
1000 use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
1003 MIPS computers running RISC-OS can support four different
1004 personalities: default, BSD 4.3, System V.3, and System V.4 (older
1005 versions of RISC-OS don't support V.4). To configure GCC for
1006 these platforms use the following configurations:
1008 `mips-mips-riscos`rev''
1009 Default configuration for RISC-OS, revision `rev'.
1011 `mips-mips-riscos`rev'bsd'
1012 BSD 4.3 configuration for RISC-OS, revision `rev'.
1014 `mips-mips-riscos`rev'sysv4'
1015 System V.4 configuration for RISC-OS, revision `rev'.
1017 `mips-mips-riscos`rev'sysv'
1018 System V.3 configuration for RISC-OS, revision `rev'.
1020 The revision `rev' mentioned above is the revision of RISC-OS to
1021 use. You must reconfigure GCC when going from a RISC-OS revision
1022 4 to RISC-OS revision 5. This has the effect of avoiding a linker
1026 In order to compile GCC on an SGI running IRIX 4, the "c.hdr.lib"
1027 option must be installed from the CD-ROM supplied from Silicon
1028 Graphics. This is found on the 2nd CD in release 4.0.1.
1030 In order to compile GCC on an SGI running IRIX 5, the
1031 "compiler_dev.hdr" subsystem must be installed from the IDO CD-ROM
1032 supplied by Silicon Graphics.
1034 `make compare' may fail on version 5 of IRIX unless you add
1035 `-save-temps' to `CFLAGS'. On these systems, the name of the
1036 assembler input file is stored in the object file, and that makes
1037 comparison fail if it differs between the `stage1' and `stage2'
1038 compilations. The option `-save-temps' forces a fixed name to be
1039 used for the assembler input file, instead of a randomly chosen
1040 name in `/tmp'. Do not add `-save-temps' unless the comparisons
1041 fail without that option. If you do you `-save-temps', you will
1042 have to manually delete the `.i' and `.s' files after each series
1045 The MIPS C compiler needs to be told to increase its table size
1046 for switch statements with the `-Wf,-XNg1500' option in order to
1047 compile `cp/parse.c'. If you use the `-O2' optimization option,
1048 you also need to use `-Olimit 3000'. Both of these options are
1049 automatically generated in the `Makefile' that the shell script
1050 `configure' builds. If you override the `CC' make variable and
1051 use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
1054 On Irix version 4.0.5F, and perhaps on some other versions as well,
1055 there is an assembler bug that reorders instructions incorrectly.
1056 To work around it, specify the target configuration
1057 `mips-sgi-irix4loser'. This configuration inhibits assembler
1060 In a compiler configured with target `mips-sgi-irix4', you can turn
1061 off assembler optimization by using the `-noasmopt' option. This
1062 compiler option passes the option `-O0' to the assembler, to
1065 The `-noasmopt' option can be useful for testing whether a problem
1066 is due to erroneous assembler reordering. Even if a problem does
1067 not go away with `-noasmopt', it may still be due to assembler
1068 reordering--perhaps GNU CC itself was miscompiled as a result.
1070 To enable debugging under Irix 5, you must use GNU as 2.5 or later,
1071 and use the `--with-gnu-as' configure option when configuring gcc.
1072 GNU as is distributed as part of the binutils package.
1075 Sony MIPS NEWS. This works in NEWSOS 5.0.1, but not in 5.0.2
1076 (which uses ELF instead of COFF). Support for 5.0.2 will probably
1077 be provided soon by volunteers. In particular, the linker does
1078 not like the code generated by GCC when shared libraries are
1082 Encore ns32000 system. Encore systems are supported only under
1086 National Semiconductor ns32000 system. Genix has bugs in `alloca'
1087 and `malloc'; you must get the compiled versions of these from GNU
1091 Go to the Berkeley universe before compiling. In addition, you
1092 probably need to create a file named `string.h' containing just
1093 one line: `#include <strings.h>'.
1096 UTEK ns32000 system ("merlin"). The C compiler that comes with
1097 this system cannot compile GNU CC; contact `tektronix!reed!mason'
1098 to get binaries of GNU CC for bootstrapping.
1102 The only operating systems supported for the IBM RT PC are AOS and
1103 MACH. GNU CC does not support AIX running on the RT. We
1104 recommend you compile GNU CC with an earlier version of itself; if
1105 you compile GNU CC with `hc', the Metaware compiler, it will work,
1106 but you will get mismatches between the stage 2 and stage 3
1107 compilers in various files. These errors are minor differences in
1108 some floating-point constants and can be safely ignored; the stage
1109 3 compiler is correct.
1113 Various early versions of each release of the IBM XLC compiler
1114 will not bootstrap GNU CC. Symptoms include differences between
1115 the stage2 and stage3 object files, and errors when compiling
1116 `libgcc.a' or `enquire'. Known problematic releases include:
1117 xlc-1.2.1.8, xlc-1.3.0.0 (distributed with AIX 3.2.5), and
1118 xlc-1.3.0.19. Both xlc-1.2.1.28 and xlc-1.3.0.24 (PTF 432238) are
1119 known to produce working versions of GNU CC, but most other recent
1120 releases correctly bootstrap GNU CC. Also, releases of AIX prior
1121 to AIX 3.2.4 include a version of the IBM assembler which does not
1122 accept debugging directives: assembler updates are available as
1123 PTFs. Also, if you are using AIX 3.2.5 or greater and the GNU
1124 assembler, you must have a version modified after October 16th,
1125 1995 in order for the GNU C compiler to build. See the file
1126 `README.RS6000' for more details on of these problems.
1128 GNU CC does not yet support the 64-bit PowerPC instructions.
1130 Objective C does not work on this architecture because it makes
1131 assumptions that are incompatible with the calling conventions.
1133 AIX on the RS/6000 provides support (NLS) for environments outside
1134 of the United States. Compilers and assemblers use NLS to support
1135 locale-specific representations of various objects including
1136 floating-point numbers ("." vs "," for separating decimal
1137 fractions). There have been problems reported where the library
1138 linked with GNU CC does not produce the same floating-point
1139 formats that the assembler accepts. If you have this problem, set
1140 the LANG environment variable to "C" or "En_US".
1142 Due to changes in the way that GNU CC invokes the binder (linker)
1143 for AIX 4.1, you may now receive warnings of duplicate symbols
1144 from the link step that were not reported before. The assembly
1145 files generated by GNU CC for AIX have always included multiple
1146 symbol definitions for certain global variable and function
1147 declarations in the original program. The warnings should not
1148 prevent the linker from producing a correct library or runnable
1153 PowerPC system in big endian mode, running System V.4.
1155 This configuration is currently under development.
1158 Embedded PowerPC system in big endian mode with -mcall-aix
1159 selected as the default. This system is currently under
1163 Embedded PowerPC system in big endian mode for use in running
1164 under the PSIM simulator. This system is currently under
1168 Embedded PowerPC system in big endian mode.
1170 This configuration is currently under development.
1174 PowerPC system in little endian mode, running System V.4.
1176 This configuration is currently under development.
1179 Embedded PowerPC system in little endian mode.
1181 This system is currently under development.
1183 `powerpcle-*-eabisim'
1184 Embedded PowerPC system in little endian mode for use in running
1185 under the PSIM simulator.
1187 This system is currently under development.
1190 Embedded PowerPC system in little endian mode.
1192 This configuration is currently under development.
1195 Don't try compiling with Vax C (`vcc'). It produces incorrect code
1196 in some cases (for example, when `alloca' is used).
1198 Meanwhile, compiling `cp/parse.c' with pcc does not work because of
1199 an internal table size limitation in that compiler. To avoid this
1200 problem, compile just the GNU C compiler first, and use it to
1201 recompile building all the languages that you want to run.
1204 See *Note Sun Install::, for information on installing GNU CC on
1208 See *Note VMS Install::, for details on how to install GNU CC on
1212 These computers are also known as the 3b2, 3b5, 3b20 and other
1213 similar names. (However, the 3b1 is actually a 68000; see *Note
1216 Don't use `-g' when compiling with the system's compiler. The
1217 system's linker seems to be unable to handle such a large program
1218 with debugging information.
1220 The system's compiler runs out of capacity when compiling `stmt.c'
1221 in GNU CC. You can work around this by building `cpp' in GNU CC
1222 first, then use that instead of the system's preprocessor with the
1223 system's C compiler to compile `stmt.c'. Here is how:
1225 mv /lib/cpp /lib/cpp.att
1227 echo '/lib/cpp.gnu -traditional ${1+"$@"}' > /lib/cpp
1230 The system's compiler produces bad code for some of the GNU CC
1231 optimization files. So you must build the stage 2 compiler without
1232 optimization. Then build a stage 3 compiler with optimization.
1233 That executable should work. Here are the necessary commands:
1235 make LANGUAGES=c CC=stage1/xgcc CFLAGS="-Bstage1/ -g"
1237 make CC=stage2/xgcc CFLAGS="-Bstage2/ -g -O"
1239 You may need to raise the ULIMIT setting to build a C++ compiler,
1240 as the file `cc1plus' is larger than one megabyte.
1242 Compilation in a Separate Directory
1243 ===================================
1245 If you wish to build the object files and executables in a directory
1246 other than the one containing the source files, here is what you must
1249 1. Make sure you have a version of Make that supports the `VPATH'
1250 feature. (GNU Make supports it, as do Make versions on most BSD
1253 2. If you have ever run `configure' in the source directory, you must
1254 undo the configuration. Do this by running:
1258 3. Go to the directory in which you want to build the compiler before
1259 running `configure':
1264 On systems that do not support symbolic links, this directory must
1265 be on the same file system as the source code directory.
1267 4. Specify where to find `configure' when you run it:
1269 ../gcc/configure ...
1271 This also tells `configure' where to find the compiler sources;
1272 `configure' takes the directory from the file name that was used to
1273 invoke it. But if you want to be sure, you can specify the source
1274 directory with the `--srcdir' option, like this:
1276 ../gcc/configure --srcdir=../gcc OTHER OPTIONS
1278 The directory you specify with `--srcdir' need not be the same as
1279 the one that `configure' is found in.
1281 Now, you can run `make' in that directory. You need not repeat the
1282 configuration steps shown above, when ordinary source files change. You
1283 must, however, run `configure' again when the configuration files
1284 change, if your system does not support symbolic links.
1286 Building and Installing a Cross-Compiler
1287 ========================================
1289 GNU CC can function as a cross-compiler for many machines, but not
1292 * Cross-compilers for the Mips as target using the Mips assembler
1293 currently do not work, because the auxiliary programs
1294 `mips-tdump.c' and `mips-tfile.c' can't be compiled on anything
1295 but a Mips. It does work to cross compile for a Mips if you use
1296 the GNU assembler and linker.
1298 * Cross-compilers between machines with different floating point
1299 formats have not all been made to work. GNU CC now has a floating
1300 point emulator with which these can work, but each target machine
1301 description needs to be updated to take advantage of it.
1303 * Cross-compilation between machines of different word sizes is
1304 somewhat problematic and sometimes does not work.
1306 Since GNU CC generates assembler code, you probably need a
1307 cross-assembler that GNU CC can run, in order to produce object files.
1308 If you want to link on other than the target machine, you need a
1309 cross-linker as well. You also need header files and libraries suitable
1310 for the target machine that you can install on the host machine.
1312 Steps of Cross-Compilation
1313 --------------------------
1315 To compile and run a program using a cross-compiler involves several
1318 * Run the cross-compiler on the host machine to produce assembler
1319 files for the target machine. This requires header files for the
1322 * Assemble the files produced by the cross-compiler. You can do this
1323 either with an assembler on the target machine, or with a
1324 cross-assembler on the host machine.
1326 * Link those files to make an executable. You can do this either
1327 with a linker on the target machine, or with a cross-linker on the
1328 host machine. Whichever machine you use, you need libraries and
1329 certain startup files (typically `crt....o') for the target
1332 It is most convenient to do all of these steps on the same host
1333 machine, since then you can do it all with a single invocation of GNU
1334 CC. This requires a suitable cross-assembler and cross-linker. For
1335 some targets, the GNU assembler and linker are available.
1337 Configuring a Cross-Compiler
1338 ----------------------------
1340 To build GNU CC as a cross-compiler, you start out by running
1341 `configure'. Use the `--target=TARGET' to specify the target type. If
1342 `configure' was unable to correctly identify the system you are running
1343 on, also specify the `--build=BUILD' option. For example, here is how
1344 to configure for a cross-compiler that produces code for an HP 68030
1345 system running BSD on a system that `configure' can correctly identify:
1347 ./configure --target=m68k-hp-bsd4.3
1349 Tools and Libraries for a Cross-Compiler
1350 ----------------------------------------
1352 If you have a cross-assembler and cross-linker available, you should
1353 install them now. Put them in the directory `/usr/local/TARGET/bin'.
1354 Here is a table of the tools you should put in this directory:
1357 This should be the cross-assembler.
1360 This should be the cross-linker.
1363 This should be the cross-archiver: a program which can manipulate
1364 archive files (linker libraries) in the target machine's format.
1367 This should be a program to construct a symbol table in an archive
1370 The installation of GNU CC will find these programs in that
1371 directory, and copy or link them to the proper place to for the
1372 cross-compiler to find them when run later.
1374 The easiest way to provide these files is to build the Binutils
1375 package and GAS. Configure them with the same `--host' and `--target'
1376 options that you use for configuring GNU CC, then build and install
1377 them. They install their executables automatically into the proper
1378 directory. Alas, they do not support all the targets that GNU CC
1381 If you want to install libraries to use with the cross-compiler,
1382 such as a standard C library, put them in the directory
1383 `/usr/local/TARGET/lib'; installation of GNU CC copies all all the
1384 files in that subdirectory into the proper place for GNU CC to find
1385 them and link with them. Here's an example of copying some libraries
1386 from a target machine:
1389 lcd /usr/local/TARGET/lib
1397 The precise set of libraries you'll need, and their locations on the
1398 target machine, vary depending on its operating system.
1400 Many targets require "start files" such as `crt0.o' and `crtn.o'
1401 which are linked into each executable; these too should be placed in
1402 `/usr/local/TARGET/lib'. There may be several alternatives for
1403 `crt0.o', for use with profiling or other compilation options. Check
1404 your target's definition of `STARTFILE_SPEC' to find out what start
1405 files it uses. Here's an example of copying these files from a target
1409 lcd /usr/local/TARGET/lib
1417 `libgcc.a' and Cross-Compilers
1418 ------------------------------
1420 Code compiled by GNU CC uses certain runtime support functions
1421 implicitly. Some of these functions can be compiled successfully with
1422 GNU CC itself, but a few cannot be. These problem functions are in the
1423 source file `libgcc1.c'; the library made from them is called
1426 When you build a native compiler, these functions are compiled with
1427 some other compiler-the one that you use for bootstrapping GNU CC.
1428 Presumably it knows how to open code these operations, or else knows how
1429 to call the run-time emulation facilities that the machine comes with.
1430 But this approach doesn't work for building a cross-compiler. The
1431 compiler that you use for building knows about the host system, not the
1434 So, when you build a cross-compiler you have to supply a suitable
1435 library `libgcc1.a' that does the job it is expected to do.
1437 To compile `libgcc1.c' with the cross-compiler itself does not work.
1438 The functions in this file are supposed to implement arithmetic
1439 operations that GNU CC does not know how to open code for your target
1440 machine. If these functions are compiled with GNU CC itself, they will
1441 compile into infinite recursion.
1443 On any given target, most of these functions are not needed. If GNU
1444 CC can open code an arithmetic operation, it will not call these
1445 functions to perform the operation. It is possible that on your target
1446 machine, none of these functions is needed. If so, you can supply an
1447 empty library as `libgcc1.a'.
1449 Many targets need library support only for multiplication and
1450 division. If you are linking with a library that contains functions for
1451 multiplication and division, you can tell GNU CC to call them directly
1452 by defining the macros `MULSI3_LIBCALL', and the like. These macros
1453 need to be defined in the target description macro file. For some
1454 targets, they are defined already. This may be sufficient to avoid the
1455 need for libgcc1.a; if so, you can supply an empty library.
1457 Some targets do not have floating point instructions; they need other
1458 functions in `libgcc1.a', which do floating arithmetic. Recent
1459 versions of GNU CC have a file which emulates floating point. With a
1460 certain amount of work, you should be able to construct a floating
1461 point emulator that can be used as `libgcc1.a'. Perhaps future
1462 versions will contain code to do this automatically and conveniently.
1463 That depends on whether someone wants to implement it.
1465 Some embedded targets come with all the necessary `libgcc1.a'
1466 routines written in C or assembler. These targets build `libgcc1.a'
1467 automatically and you do not need to do anything special for them.
1468 Other embedded targets do not need any `libgcc1.a' routines since all
1469 the necessary operations are supported by the hardware.
1471 If your target system has another C compiler, you can configure GNU
1472 CC as a native compiler on that machine, build just `libgcc1.a' with
1473 `make libgcc1.a' on that machine, and use the resulting file with the
1474 cross-compiler. To do this, execute the following on the target
1478 ./configure --host=sparc --target=sun3
1481 And then this on the host machine:
1489 Another way to provide the functions you need in `libgcc1.a' is to
1490 define the appropriate `perform_...' macros for those functions. If
1491 these definitions do not use the C arithmetic operators that they are
1492 meant to implement, you should be able to compile them with the
1493 cross-compiler you are building. (If these definitions already exist
1494 for your target file, then you are all set.)
1496 To build `libgcc1.a' using the perform macros, use
1497 `LIBGCC1=libgcc1.a OLDCC=./xgcc' when building the compiler.
1498 Otherwise, you should place your replacement library under the name
1499 `libgcc1.a' in the directory in which you will build the
1500 cross-compiler, before you run `make'.
1502 Cross-Compilers and Header Files
1503 --------------------------------
1505 If you are cross-compiling a standalone program or a program for an
1506 embedded system, then you may not need any header files except the few
1507 that are part of GNU CC (and those of your program). However, if you
1508 intend to link your program with a standard C library such as `libc.a',
1509 then you probably need to compile with the header files that go with
1510 the library you use.
1512 The GNU C compiler does not come with these files, because (1) they
1513 are system-specific, and (2) they belong in a C library, not in a
1516 If the GNU C library supports your target machine, then you can get
1517 the header files from there (assuming you actually use the GNU library
1518 when you link your program).
1520 If your target machine comes with a C compiler, it probably comes
1521 with suitable header files also. If you make these files accessible
1522 from the host machine, the cross-compiler can use them also.
1524 Otherwise, you're on your own in finding header files to use when
1527 When you have found suitable header files, put them in
1528 `/usr/local/TARGET/include', before building the cross compiler. Then
1529 installation will run fixincludes properly and install the corrected
1530 versions of the header files where the compiler will use them.
1532 Provide the header files before you build the cross-compiler, because
1533 the build stage actually runs the cross-compiler to produce parts of
1534 `libgcc.a'. (These are the parts that *can* be compiled with GNU CC.)
1535 Some of them need suitable header files.
1537 Here's an example showing how to copy the header files from a target
1538 machine. On the target machine, do this:
1540 (cd /usr/include; tar cf - .) > tarfile
1542 Then, on the host machine, do this:
1545 lcd /usr/local/TARGET/include
1550 Actually Building the Cross-Compiler
1551 ------------------------------------
1553 Now you can proceed just as for compiling a single-machine compiler
1554 through the step of building stage 1. If you have not provided some
1555 sort of `libgcc1.a', then compilation will give up at the point where
1556 it needs that file, printing a suitable error message. If you do
1557 provide `libgcc1.a', then building the compiler will automatically
1558 compile and link a test program called `libgcc1-test'; if you get
1559 errors in the linking, it means that not all of the necessary routines
1560 in `libgcc1.a' are available.
1562 You must provide the header file `float.h'. One way to do this is
1563 to compile `enquire' and run it on your target machine. The job of
1564 `enquire' is to run on the target machine and figure out by experiment
1565 the nature of its floating point representation. `enquire' records its
1566 findings in the header file `float.h'. If you can't produce this file
1567 by running `enquire' on the target machine, then you will need to come
1568 up with a suitable `float.h' in some other way (or else, avoid using it
1571 Do not try to build stage 2 for a cross-compiler. It doesn't work to
1572 rebuild GNU CC as a cross-compiler using the cross-compiler, because
1573 that would produce a program that runs on the target machine, not on the
1574 host. For example, if you compile a 386-to-68030 cross-compiler with
1575 itself, the result will not be right either for the 386 (because it was
1576 compiled into 68030 code) or for the 68030 (because it was configured
1577 for a 386 as the host). If you want to compile GNU CC into 68030 code,
1578 whether you compile it on a 68030 or with a cross-compiler on a 386, you
1579 must specify a 68030 as the host when you configure it.
1581 To install the cross-compiler, use `make install', as usual.
1583 Installing GNU CC on the Sun
1584 ============================
1586 On Solaris (version 2.1), do not use the linker or other tools in
1587 `/usr/ucb' to build GNU CC. Use `/usr/ccs/bin'.
1589 Make sure the environment variable `FLOAT_OPTION' is not set when
1590 you compile `libgcc.a'. If this option were set to `f68881' when
1591 `libgcc.a' is compiled, the resulting code would demand to be linked
1592 with a special startup file and would not link properly without special
1595 There is a bug in `alloca' in certain versions of the Sun library.
1596 To avoid this bug, install the binaries of GNU CC that were compiled by
1597 GNU CC. They use `alloca' as a built-in function and never the one in
1600 Some versions of the Sun compiler crash when compiling GNU CC. The
1601 problem is a segmentation fault in cpp. This problem seems to be due to
1602 the bulk of data in the environment variables. You may be able to avoid
1603 it by using the following command to compile GNU CC with Sun CC:
1605 make CC="TERMCAP=x OBJS=x LIBFUNCS=x STAGESTUFF=x cc"
1607 Installing GNU CC on VMS
1608 ========================
1610 The VMS version of GNU CC is distributed in a backup saveset
1611 containing both source code and precompiled binaries.
1613 To install the `gcc' command so you can use the compiler easily, in
1614 the same manner as you use the VMS C compiler, you must install the VMS
1615 CLD file for GNU CC as follows:
1617 1. Define the VMS logical names `GNU_CC' and `GNU_CC_INCLUDE' to
1618 point to the directories where the GNU CC executables
1619 (`gcc-cpp.exe', `gcc-cc1.exe', etc.) and the C include files are
1620 kept respectively. This should be done with the commands:
1622 $ assign /system /translation=concealed -
1624 $ assign /system /translation=concealed -
1625 disk:[gcc.include.] gnu_cc_include
1627 with the appropriate disk and directory names. These commands can
1628 be placed in your system startup file so they will be executed
1629 whenever the machine is rebooted. You may, if you choose, do this
1630 via the `GCC_INSTALL.COM' script in the `[GCC]' directory.
1632 2. Install the `GCC' command with the command line:
1634 $ set command /table=sys$common:[syslib]dcltables -
1635 /output=sys$common:[syslib]dcltables gnu_cc:[000000]gcc
1636 $ install replace sys$common:[syslib]dcltables
1638 3. To install the help file, do the following:
1640 $ library/help sys$library:helplib.hlb gcc.hlp
1642 Now you can invoke the compiler with a command like `gcc /verbose
1643 file.c', which is equivalent to the command `gcc -v -c file.c' in
1646 If you wish to use GNU C++ you must first install GNU CC, and then
1647 perform the following steps:
1649 1. Define the VMS logical name `GNU_GXX_INCLUDE' to point to the
1650 directory where the preprocessor will search for the C++ header
1651 files. This can be done with the command:
1653 $ assign /system /translation=concealed -
1654 disk:[gcc.gxx_include.] gnu_gxx_include
1656 with the appropriate disk and directory name. If you are going to
1657 be using libg++, this is where the libg++ install procedure will
1658 install the libg++ header files.
1660 2. Obtain the file `gcc-cc1plus.exe', and place this in the same
1661 directory that `gcc-cc1.exe' is kept.
1663 The GNU C++ compiler can be invoked with a command like `gcc /plus
1664 /verbose file.cc', which is equivalent to the command `g++ -v -c
1667 We try to put corresponding binaries and sources on the VMS
1668 distribution tape. But sometimes the binaries will be from an older
1669 version than the sources, because we don't always have time to update
1670 them. (Use the `/version' option to determine the version number of
1671 the binaries and compare it with the source file `version.c' to tell
1672 whether this is so.) In this case, you should use the binaries you get
1673 to recompile the sources. If you must recompile, here is how:
1675 1. Execute the command procedure `vmsconfig.com' to set up the files
1676 `tm.h', `config.h', `aux-output.c', and `md.', and to create files
1677 `tconfig.h' and `hconfig.h'. This procedure also creates several
1678 linker option files used by `make-cc1.com' and a data file used by
1683 2. Setup the logical names and command tables as defined above. In
1684 addition, define the VMS logical name `GNU_BISON' to point at the
1685 to the directories where the Bison executable is kept. This
1686 should be done with the command:
1688 $ assign /system /translation=concealed -
1689 disk:[bison.] gnu_bison
1691 You may, if you choose, use the `INSTALL_BISON.COM' script in the
1692 `[BISON]' directory.
1694 3. Install the `BISON' command with the command line:
1696 $ set command /table=sys$common:[syslib]dcltables -
1697 /output=sys$common:[syslib]dcltables -
1698 gnu_bison:[000000]bison
1699 $ install replace sys$common:[syslib]dcltables
1701 4. Type `@make-gcc' to recompile everything (alternatively, submit
1702 the file `make-gcc.com' to a batch queue). If you wish to build
1703 the GNU C++ compiler as well as the GNU CC compiler, you must
1704 first edit `make-gcc.com' and follow the instructions that appear
1707 5. In order to use GCC, you need a library of functions which GCC
1708 compiled code will call to perform certain tasks, and these
1709 functions are defined in the file `libgcc2.c'. To compile this
1710 you should use the command procedure `make-l2.com', which will
1711 generate the library `libgcc2.olb'. `libgcc2.olb' should be built
1712 using the compiler built from the same distribution that
1713 `libgcc2.c' came from, and `make-gcc.com' will automatically do
1714 all of this for you.
1716 To install the library, use the following commands:
1718 $ library gnu_cc:[000000]gcclib/delete=(new,eprintf)
1719 $ library gnu_cc:[000000]gcclib/delete=L_*
1720 $ library libgcc2/extract=*/output=libgcc2.obj
1721 $ library gnu_cc:[000000]gcclib libgcc2.obj
1723 The first command simply removes old modules that will be replaced
1724 with modules from `libgcc2' under different module names. The
1725 modules `new' and `eprintf' may not actually be present in your
1726 `gcclib.olb'--if the VMS librarian complains about those modules
1727 not being present, simply ignore the message and continue on with
1728 the next command. The second command removes the modules that
1729 came from the previous version of the library `libgcc2.c'.
1731 Whenever you update the compiler on your system, you should also
1732 update the library with the above procedure.
1734 6. You may wish to build GCC in such a way that no files are written
1735 to the directory where the source files reside. An example would
1736 be the when the source files are on a read-only disk. In these
1737 cases, execute the following DCL commands (substituting your
1740 $ assign dua0:[gcc.build_dir.]/translation=concealed, -
1741 dua1:[gcc.source_dir.]/translation=concealed gcc_build
1742 $ set default gcc_build:[000000]
1744 where the directory `dua1:[gcc.source_dir]' contains the source
1745 code, and the directory `dua0:[gcc.build_dir]' is meant to contain
1746 all of the generated object files and executables. Once you have
1747 done this, you can proceed building GCC as described above. (Keep
1748 in mind that `gcc_build' is a rooted logical name, and thus the
1749 device names in each element of the search list must be an actual
1750 physical device name rather than another rooted logical name).
1752 7. *If you are building GNU CC with a previous version of GNU CC, you
1753 also should check to see that you have the newest version of the
1754 assembler*. In particular, GNU CC version 2 treats global constant
1755 variables slightly differently from GNU CC version 1, and GAS
1756 version 1.38.1 does not have the patches required to work with GCC
1757 version 2. If you use GAS 1.38.1, then `extern const' variables
1758 will not have the read-only bit set, and the linker will generate
1759 warning messages about mismatched psect attributes for these
1760 variables. These warning messages are merely a nuisance, and can
1763 If you are compiling with a version of GNU CC older than 1.33,
1764 specify `/DEFINE=("inline=")' as an option in all the
1765 compilations. This requires editing all the `gcc' commands in
1766 `make-cc1.com'. (The older versions had problems supporting
1767 `inline'.) Once you have a working 1.33 or newer GNU CC, you can
1768 change this file back.
1770 8. If you want to build GNU CC with the VAX C compiler, you will need
1771 to make minor changes in `make-cccp.com' and `make-cc1.com' to
1772 choose alternate definitions of `CC', `CFLAGS', and `LIBS'. See
1773 comments in those files. However, you must also have a working
1774 version of the GNU assembler (GNU as, aka GAS) as it is used as
1775 the back-end for GNU CC to produce binary object modules and is
1776 not included in the GNU CC sources. GAS is also needed to compile
1777 `libgcc2' in order to build `gcclib' (see above); `make-l2.com'
1778 expects to be able to find it operational in
1779 `gnu_cc:[000000]gnu-as.exe'.
1781 To use GNU CC on VMS, you need the VMS driver programs `gcc.exe',
1782 `gcc.com', and `gcc.cld'. They are distributed with the VMS
1783 binaries (`gcc-vms') rather than the GNU CC sources. GAS is also
1784 included in `gcc-vms', as is Bison.
1786 Once you have successfully built GNU CC with VAX C, you should use
1787 the resulting compiler to rebuild itself. Before doing this, be
1788 sure to restore the `CC', `CFLAGS', and `LIBS' definitions in
1789 `make-cccp.com' and `make-cc1.com'. The second generation
1790 compiler will be able to take advantage of many optimizations that
1791 must be suppressed when building with other compilers.
1793 Under previous versions of GNU CC, the generated code would
1794 occasionally give strange results when linked with the sharable
1795 `VAXCRTL' library. Now this should work.
1797 Even with this version, however, GNU CC itself should not be linked
1798 with the sharable `VAXCRTL'. The version of `qsort' in `VAXCRTL' has a
1799 bug (known to be present in VMS versions V4.6 through V5.5) which
1800 causes the compiler to fail.
1802 The executables are generated by `make-cc1.com' and `make-cccp.com'
1803 use the object library version of `VAXCRTL' in order to make use of the
1804 `qsort' routine in `gcclib.olb'. If you wish to link the compiler
1805 executables with the shareable image version of `VAXCRTL', you should
1806 edit the file `tm.h' (created by `vmsconfig.com') to define the macro
1809 `QSORT_WORKAROUND' is always defined when GNU CC is compiled with
1810 VAX C, to avoid a problem in case `gcclib.olb' is not yet available.
1815 Many target systems do not have support in the assembler and linker
1816 for "constructors"--initialization functions to be called before the
1817 official "start" of `main'. On such systems, GNU CC uses a utility
1818 called `collect2' to arrange to call these functions at start time.
1820 The program `collect2' works by linking the program once and looking
1821 through the linker output file for symbols with particular names
1822 indicating they are constructor functions. If it finds any, it creates
1823 a new temporary `.c' file containing a table of them, compiles it, and
1824 links the program a second time including that file.
1826 The actual calls to the constructors are carried out by a subroutine
1827 called `__main', which is called (automatically) at the beginning of
1828 the body of `main' (provided `main' was compiled with GNU CC). Calling
1829 `__main' is necessary, even when compiling C code, to allow linking C
1830 and C++ object code together. (If you use `-nostdlib', you get an
1831 unresolved reference to `__main', since it's defined in the standard
1832 GCC library. Include `-lgcc' at the end of your compiler command line
1833 to resolve this reference.)
1835 The program `collect2' is installed as `ld' in the directory where
1836 the passes of the compiler are installed. When `collect2' needs to
1837 find the *real* `ld', it tries the following file names:
1839 * `real-ld' in the directories listed in the compiler's search
1842 * `real-ld' in the directories listed in the environment variable
1845 * The file specified in the `REAL_LD_FILE_NAME' configuration macro,
1848 * `ld' in the compiler's search directories, except that `collect2'
1849 will not execute itself recursively.
1853 "The compiler's search directories" means all the directories where
1854 `gcc' searches for passes of the compiler. This includes directories
1855 that you specify with `-B'.
1857 Cross-compilers search a little differently:
1859 * `real-ld' in the compiler's search directories.
1861 * `TARGET-real-ld' in `PATH'.
1863 * The file specified in the `REAL_LD_FILE_NAME' configuration macro,
1866 * `ld' in the compiler's search directories.
1868 * `TARGET-ld' in `PATH'.
1870 `collect2' explicitly avoids running `ld' using the file name under
1871 which `collect2' itself was invoked. In fact, it remembers up a list
1872 of such names--in case one copy of `collect2' finds another copy (or
1873 version) of `collect2' installed as `ld' in a second place in the
1876 `collect2' searches for the utilities `nm' and `strip' using the
1877 same algorithm as above for `ld'.
1879 Standard Header File Directories
1880 ================================
1882 `GCC_INCLUDE_DIR' means the same thing for native and cross. It is
1883 where GNU CC stores its private include files, and also where GNU CC
1884 stores the fixed include files. A cross compiled GNU CC runs
1885 `fixincludes' on the header files in `$(tooldir)/include'. (If the
1886 cross compilation header files need to be fixed, they must be installed
1887 before GNU CC is built. If the cross compilation header files are
1888 already suitable for ANSI C and GNU CC, nothing special need be done).
1890 `GPLUS_INCLUDE_DIR' means the same thing for native and cross. It
1891 is where `g++' looks first for header files. `libg++' installs only
1892 target independent header files in that directory.
1894 `LOCAL_INCLUDE_DIR' is used only for a native compiler. It is
1895 normally `/usr/local/include'. GNU CC searches this directory so that
1896 users can install header files in `/usr/local/include'.
1898 `CROSS_INCLUDE_DIR' is used only for a cross compiler. GNU CC
1899 doesn't install anything there.
1901 `TOOL_INCLUDE_DIR' is used for both native and cross compilers. It
1902 is the place for other packages to install header files that GNU CC will
1903 use. For a cross-compiler, this is the equivalent of `/usr/include'.
1904 When you build a cross-compiler, `fixincludes' processes any header
1905 files in this directory.