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.
6 Note most of this information is out of date and superceded by the EGCS
7 install procedures. It is provided for historical reference only.
12 Here is the procedure for installing GNU CC on a Unix system. See
13 *Note VMS Install::, for VMS systems. In this section we assume you
14 compile in the same directory that contains the source files; see *Note
15 Other Dir::, to find out how to compile in a separate directory on Unix
18 You cannot install GNU C by itself on MSDOS; it will not compile
19 under any MSDOS compiler except itself. You need to get the complete
20 compilation package DJGPP, which includes binaries as well as sources,
21 and includes all the necessary compilation tools and libraries.
23 1. If you have built GNU CC previously in the same directory for a
24 different target machine, do `make distclean' to delete all files
25 that might be invalid. One of the files this deletes is
26 `Makefile'; if `make distclean' complains that `Makefile' does not
27 exist, it probably means that the directory is already suitably
30 2. On a System V release 4 system, make sure `/usr/bin' precedes
31 `/usr/ucb' in `PATH'. The `cc' command in `/usr/ucb' uses
32 libraries which have bugs.
34 3. Specify the host, build and target machine configurations. You do
35 this by running the file `configure'.
37 The "build" machine is the system which you are using, the "host"
38 machine is the system where you want to run the resulting compiler
39 (normally the build machine), and the "target" machine is the
40 system for which you want the compiler to generate code.
42 If you are building a compiler to produce code for the machine it
43 runs on (a native compiler), you normally do not need to specify
44 any operands to `configure'; it will try to guess the type of
45 machine you are on and use that as the build, host and target
46 machines. So you don't need to specify a configuration when
47 building a native compiler unless `configure' cannot figure out
48 what your configuration is or guesses wrong.
50 In those cases, specify the build machine's "configuration name"
51 with the `--build' option; the host and target will default to be
52 the same as the build machine. (If you are building a
53 cross-compiler, see *Note Cross-Compiler::.)
57 ./configure --build=sparc-sun-sunos4.1
59 A configuration name may be canonical or it may be more or less
62 A canonical configuration name has three parts, separated by
63 dashes. It looks like this: `CPU-COMPANY-SYSTEM'. (The three
64 parts may themselves contain dashes; `configure' can figure out
65 which dashes serve which purpose.) For example,
66 `m68k-sun-sunos4.1' specifies a Sun 3.
68 You can also replace parts of the configuration by nicknames or
69 aliases. For example, `sun3' stands for `m68k-sun', so
70 `sun3-sunos4.1' is another way to specify a Sun 3. You can also
71 use simply `sun3-sunos', since the version of SunOS is assumed by
72 default to be version 4. `sun3-bsd' also works, since `configure'
73 knows that the only BSD variant on a Sun 3 is SunOS.
75 You can specify a version number after any of the system types,
76 and some of the CPU types. In most cases, the version is
77 irrelevant, and will be ignored. So you might as well specify the
78 version if you know it.
80 See *Note Configurations::, for a list of supported configuration
81 names and notes on many of the configurations. You should check
82 the notes in that section before proceeding any further with the
83 installation of GNU CC.
85 There are four additional options you can specify independently to
86 describe variant hardware and software configurations. These are
87 `--with-gnu-as', `--with-gnu-ld', `--with-stabs' and `--nfp'.
90 If you will use GNU CC with the GNU assembler (GAS), you
91 should declare this by using the `--with-gnu-as' option when
94 Using this option does not install GAS. It only modifies the
95 output of GNU CC to work with GAS. Building and installing
98 Conversely, if you *do not* wish to use GAS and do not specify
99 `--with-gnu-as' when building GNU CC, it is up to you to make
100 sure that GAS is not installed. GNU CC searches for a
101 program named `as' in various directories; if the program it
102 finds is GAS, then it runs GAS. If you are not sure where
103 GNU CC finds the assembler it is using, try specifying `-v'
106 The systems where it makes a difference whether you use GAS
108 `hppa1.0-ANY-ANY', `hppa1.1-ANY-ANY', `i386-ANY-sysv',
110 `i860-ANY-bsd', `m68k-bull-sysv', `m68k-hp-hpux',
112 `m68k-altos-sysv', `m68000-hp-hpux', `m68000-att-sysv',
113 `ANY-lynx-lynxos', and `mips-ANY'). On any other system,
114 `--with-gnu-as' has no effect.
116 On the systems listed above (except for the HP-PA, for ISC on
117 the 386, and for `mips-sgi-irix5.*'), if you use GAS, you
118 should also use the GNU linker (and specify `--with-gnu-ld').
121 Specify the option `--with-gnu-ld' if you plan to use the GNU
124 This option does not cause the GNU linker to be installed; it
125 just modifies the behavior of GNU CC to work with the GNU
126 linker. Specifically, it inhibits the installation of
127 `collect2', a program which otherwise serves as a front-end
128 for the system's linker on most configurations.
131 On MIPS based systems and on Alphas, you must specify whether
132 you want GNU CC to create the normal ECOFF debugging format,
133 or to use BSD-style stabs passed through the ECOFF symbol
134 table. The normal ECOFF debug format cannot fully handle
135 languages other than C. BSD stabs format can handle other
136 languages, but it only works with the GNU debugger GDB.
138 Normally, GNU CC uses the ECOFF debugging format by default;
139 if you prefer BSD stabs, specify `--with-stabs' when you
142 No matter which default you choose when you configure GNU CC,
143 the user can use the `-gcoff' and `-gstabs+' options to
144 specify explicitly the debug format for a particular
147 `--with-stabs' is meaningful on the ISC system on the 386,
148 also, if `--with-gas' is used. It selects use of stabs
149 debugging information embedded in COFF output. This kind of
150 debugging information supports C++ well; ordinary COFF
151 debugging information does not.
153 `--with-stabs' is also meaningful on 386 systems running
154 SVR4. It selects use of stabs debugging information embedded
155 in ELF output. The C++ compiler currently (2.6.0) does not
156 support the DWARF debugging information normally used on 386
157 SVR4 platforms; stabs provide a workable alternative. This
158 requires gas and gdb, as the normal SVR4 tools can not
159 generate or interpret stabs.
162 On certain systems, you must specify whether the machine has
163 a floating point unit. These systems include
164 `m68k-sun-sunosN' and `m68k-isi-bsd'. On any other system,
165 `--nfp' currently has no effect, though perhaps there are
166 other systems where it could usefully make a difference.
168 The `configure' script searches subdirectories of the source
169 directory for other compilers that are to be integrated into GNU
170 CC. The GNU compiler for C++, called G++ is in a subdirectory
171 named `cp'. `configure' inserts rules into `Makefile' to build
172 all of those compilers.
174 Here we spell out what files will be set up by `configure'.
175 Normally you need not be concerned with these files.
177 * A file named `config.h' is created that contains a `#include'
178 of the top-level config file for the machine you will run the
179 compiler on (*note The Configuration File:
180 (gcc.info)Config.). This file is responsible for defining
181 information about the host machine. It includes `tm.h'.
183 The top-level config file is located in the subdirectory
184 `config'. Its name is always `xm-SOMETHING.h'; usually
185 `xm-MACHINE.h', but there are some exceptions.
187 If your system does not support symbolic links, you might
188 want to set up `config.h' to contain a `#include' command
189 which refers to the appropriate file.
191 * A file named `tconfig.h' is created which includes the
192 top-level config file for your target machine. This is used
193 for compiling certain programs to run on that machine.
195 * A file named `tm.h' is created which includes the
196 machine-description macro file for your target machine. It
197 should be in the subdirectory `config' and its name is often
200 * The command file `configure' also constructs the file
201 `Makefile' by adding some text to the template file
202 `Makefile.in'. The additional text comes from files in the
203 `config' directory, named `t-TARGET' and `x-HOST'. If these
204 files do not exist, it means nothing needs to be added for a
205 given target or host.
207 4. The standard directory for installing GNU CC is `/usr/local/lib'.
208 If you want to install its files somewhere else, specify
209 `--prefix=DIR' when you run `configure'. Here DIR is a directory
210 name to use instead of `/usr/local' for all purposes with one
211 exception: the directory `/usr/local/include' is searched for
212 header files no matter where you install the compiler. To override
213 this name, use the `--local-prefix' option below.
215 5. Specify `--local-prefix=DIR' if you want the compiler to search
216 directory `DIR/include' for locally installed header files
217 *instead* of `/usr/local/include'.
219 You should specify `--local-prefix' *only* if your site has a
220 different convention (not `/usr/local') for where to put
223 *Do not* specify `/usr' as the `--local-prefix'! The directory
224 you use for `--local-prefix' *must not* contain any of the
225 system's standard header files. If it did contain them, certain
226 programs would be miscompiled (including GNU Emacs, on certain
227 targets), because this would override and nullify the header file
228 corrections made by the `fixincludes' script.
230 6. Make sure the Bison parser generator is installed. (This is
231 unnecessary if the Bison output files `c-parse.c' and `cexp.c' are
232 more recent than `c-parse.y' and `cexp.y' and you do not plan to
233 change the `.y' files.)
235 Bison versions older than Sept 8, 1988 will produce incorrect
236 output for `c-parse.c'.
238 7. If you have chosen a configuration for GNU CC which requires other
239 GNU tools (such as GAS or the GNU linker) instead of the standard
240 system tools, install the required tools in the build directory
241 under the names `as', `ld' or whatever is appropriate. This will
242 enable the compiler to find the proper tools for compilation of
243 the program `enquire'.
245 Alternatively, you can do subsequent compilation using a value of
246 the `PATH' environment variable such that the necessary GNU tools
247 come before the standard system tools.
249 8. Build the compiler. Just type `make LANGUAGES=c' in the compiler
252 `LANGUAGES=c' specifies that only the C compiler should be
253 compiled. The makefile normally builds compilers for all the
254 supported languages; currently, C, C++ and Objective C. However,
255 C is the only language that is sure to work when you build with
256 other non-GNU C compilers. In addition, building anything but C
257 at this stage is a waste of time.
259 In general, you can specify the languages to build by typing the
260 argument `LANGUAGES="LIST"', where LIST is one or more words from
261 the list `c', `c++', and `objective-c'. If you have any
262 additional GNU compilers as subdirectories of the GNU CC source
263 directory, you may also specify their names in this list.
265 Ignore any warnings you may see about "statement not reached" in
266 `insn-emit.c'; they are normal. Also, warnings about "unknown
267 escape sequence" are normal in `genopinit.c' and perhaps some
268 other files. Likewise, you should ignore warnings about "constant
269 is so large that it is unsigned" in `insn-emit.c' and
270 `insn-recog.c' and a warning about a comparison always being zero
271 in `enquire.o'. Any other compilation errors may represent bugs in
272 the port to your machine or operating system, and should be
273 investigated and reported.
275 Some commercial compilers fail to compile GNU CC because they have
276 bugs or limitations. For example, the Microsoft compiler is said
277 to run out of macro space. Some Ultrix compilers run out of
278 expression space; then you need to break up the statement where
281 9. If you are building a cross-compiler, stop here. *Note
284 10. Move the first-stage object files and executables into a
285 subdirectory with this command:
289 The files are moved into a subdirectory named `stage1'. Once
290 installation is complete, you may wish to delete these files with
293 11. If you have chosen a configuration for GNU CC which requires other
294 GNU tools (such as GAS or the GNU linker) instead of the standard
295 system tools, install the required tools in the `stage1'
296 subdirectory under the names `as', `ld' or whatever is
297 appropriate. This will enable the stage 1 compiler to find the
298 proper tools in the following stage.
300 Alternatively, you can do subsequent compilation using a value of
301 the `PATH' environment variable such that the necessary GNU tools
302 come before the standard system tools.
304 12. Recompile the compiler with itself, with this command:
306 make CC="stage1/xgcc -Bstage1/" CFLAGS="-g -O2"
308 This is called making the stage 2 compiler.
310 The command shown above builds compilers for all the supported
311 languages. If you don't want them all, you can specify the
312 languages to build by typing the argument `LANGUAGES="LIST"'. LIST
313 should contain one or more words from the list `c', `c++',
314 `objective-c', and `proto'. Separate the words with spaces.
315 `proto' stands for the programs `protoize' and `unprotoize'; they
316 are not a separate language, but you use `LANGUAGES' to enable or
317 disable their installation.
319 If you are going to build the stage 3 compiler, then you might
320 want to build only the C language in stage 2.
322 Once you have built the stage 2 compiler, if you are short of disk
323 space, you can delete the subdirectory `stage1'.
325 On a 68000 or 68020 system lacking floating point hardware, unless
326 you have selected a `tm.h' file that expects by default that there
327 is no such hardware, do this instead:
329 make CC="stage1/xgcc -Bstage1/" CFLAGS="-g -O2 -msoft-float"
331 13. If you wish to test the compiler by compiling it with itself one
332 more time, install any other necessary GNU tools (such as GAS or
333 the GNU linker) in the `stage2' subdirectory as you did in the
334 `stage1' subdirectory, then do this:
337 make CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O2"
339 This is called making the stage 3 compiler. Aside from the `-B'
340 option, the compiler options should be the same as when you made
341 the stage 2 compiler. But the `LANGUAGES' option need not be the
342 same. The command shown above builds compilers for all the
343 supported languages; if you don't want them all, you can specify
344 the languages to build by typing the argument `LANGUAGES="LIST"',
347 If you do not have to install any additional GNU tools, you may
350 make bootstrap LANGUAGES=LANGUAGE-LIST BOOT_CFLAGS=OPTION-LIST
352 instead of making `stage1', `stage2', and performing the two
355 14. Then compare the latest object files with the stage 2 object
356 files--they ought to be identical, aside from time stamps (if any).
358 On some systems, meaningful comparison of object files is
359 impossible; they always appear "different." This is currently
360 true on Solaris and some systems that use ELF object file format.
361 On some versions of Irix on SGI machines and DEC Unix (OSF/1) on
362 Alpha systems, you will not be able to compare the files without
363 specifying `-save-temps'; see the description of individual
364 systems above to see if you get comparison failures. You may have
365 similar problems on other systems.
367 Use this command to compare the files:
371 This will mention any object files that differ between stage 2 and
372 stage 3. Any difference, no matter how innocuous, indicates that
373 the stage 2 compiler has compiled GNU CC incorrectly, and is
374 therefore a potentially serious bug which you should investigate
377 If your system does not put time stamps in the object files, then
378 this is a faster way to compare them (using the Bourne shell):
381 cmp $file stage2/$file
384 If you have built the compiler with the `-mno-mips-tfile' option on
385 MIPS machines, you will not be able to compare the files.
387 15. Install the compiler driver, the compiler's passes and run-time
388 support with `make install'. Use the same value for `CC',
389 `CFLAGS' and `LANGUAGES' that you used when compiling the files
390 that are being installed. One reason this is necessary is that
391 some versions of Make have bugs and recompile files gratuitously
392 when you do this step. If you use the same variable values, those
393 files will be recompiled properly.
395 For example, if you have built the stage 2 compiler, you can use
396 the following command:
398 make install CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O" LANGUAGES="LIST"
400 This copies the files `cc1', `cpp' and `libgcc.a' to files `cc1',
401 `cpp' and `libgcc.a' in the directory
402 `/usr/local/lib/gcc-lib/TARGET/VERSION', which is where the
403 compiler driver program looks for them. Here TARGET is the target
404 machine type specified when you ran `configure', and VERSION is
405 the version number of GNU CC. This naming scheme permits various
406 versions and/or cross-compilers to coexist.
408 This also copies the driver program `xgcc' into
409 `/usr/local/bin/gcc', so that it appears in typical execution
412 On some systems, this command causes recompilation of some files.
413 This is usually due to bugs in `make'. You should either ignore
414 this problem, or use GNU Make.
416 *Warning: there is a bug in `alloca' in the Sun library. To avoid
417 this bug, be sure to install the executables of GNU CC that were
418 compiled by GNU CC. (That is, the executables from stage 2 or 3,
419 not stage 1.) They use `alloca' as a built-in function and never
420 the one in the library.*
422 (It is usually better to install GNU CC executables from stage 2
423 or 3, since they usually run faster than the ones compiled with
424 some other compiler.)
426 16. If you're going to use C++, it's likely that you need to also
427 install the libg++ distribution. It should be available from the
428 same place where you got the GNU C distribution. Just as GNU C
429 does not distribute a C runtime library, it also does not include
430 a C++ run-time library. All I/O functionality, special class
431 libraries, etc., are available in the libg++ distribution.
433 Configurations Supported by GNU CC
434 ==================================
436 Here are the possible CPU types:
438 1750a, a29k, alpha, arm, cN, clipper, dsp16xx, elxsi, h8300,
439 hppa1.0, hppa1.1, i370, i386, i486, i586, i860, i960, m68000, m68k,
440 m88k, mips, mipsel, mips64, mips64el, ns32k, powerpc, powerpcle,
441 pyramid, romp, rs6000, sh, sparc, sparclite, sparc64, vax, we32k.
443 Here are the recognized company names. As you can see, customary
444 abbreviations are used rather than the longer official names.
446 acorn, alliant, altos, apollo, att, bull, cbm, convergent, convex,
447 crds, dec, dg, dolphin, elxsi, encore, harris, hitachi, hp, ibm,
448 intergraph, isi, mips, motorola, ncr, next, ns, omron, plexus,
449 sequent, sgi, sony, sun, tti, unicom, wrs.
451 The company name is meaningful only to disambiguate when the rest of
452 the information supplied is insufficient. You can omit it, writing
453 just `CPU-SYSTEM', if it is not needed. For example, `vax-ultrix4.2'
454 is equivalent to `vax-dec-ultrix4.2'.
456 Here is a list of system types:
458 386bsd, aix, acis, amigaos, aos, aout, bosx, bsd, clix, coff,
459 ctix, cxux, dgux, dynix, ebmon, ecoff, elf, esix, freebsd, hms,
460 genix, gnu, gnu/linux, hiux, hpux, iris, irix, isc, luna, lynxos,
461 mach, minix, msdos, mvs, netbsd, newsos, nindy, ns, osf, osfrose,
462 ptx, riscix, riscos, rtu, sco, sim, solaris, sunos, sym, sysv,
463 udi, ultrix, unicos, uniplus, unos, vms, vsta, vxworks, winnt,
466 You can omit the system type; then `configure' guesses the operating
467 system from the CPU and company.
469 You can add a version number to the system type; this may or may not
470 make a difference. For example, you can write `bsd4.3' or `bsd4.4' to
471 distinguish versions of BSD. In practice, the version number is most
472 needed for `sysv3' and `sysv4', which are often treated differently.
474 If you specify an impossible combination such as `i860-dg-vms', then
475 you may get an error message from `configure', or it may ignore part of
476 the information and do the best it can with the rest. `configure'
477 always prints the canonical name for the alternative that it used. GNU
478 CC does not support all possible alternatives.
480 Often a particular model of machine has a name. Many machine names
481 are recognized as aliases for CPU/company combinations. Thus, the
482 machine name `sun3', mentioned above, is an alias for `m68k-sun'.
483 Sometimes we accept a company name as a machine name, when the name is
484 popularly used for a particular machine. Here is a table of the known
487 3300, 3b1, 3bN, 7300, altos3068, altos, apollo68, att-7300,
488 balance, convex-cN, crds, decstation-3100, decstation, delta,
489 encore, fx2800, gmicro, hp7NN, hp8NN, hp9k2NN, hp9k3NN, hp9k7NN,
490 hp9k8NN, iris4d, iris, isi68, m3230, magnum, merlin, miniframe,
491 mmax, news-3600, news800, news, next, pbd, pc532, pmax, powerpc,
492 powerpcle, ps2, risc-news, rtpc, sun2, sun386i, sun386, sun3,
493 sun4, symmetry, tower-32, tower.
495 Remember that a machine name specifies both the cpu type and the company
496 name. If you want to install your own homemade configuration files,
497 you can use `local' as the company name to access them. If you use
498 configuration `CPU-local', the configuration name without the cpu prefix
499 is used to form the configuration file names.
501 Thus, if you specify `m68k-local', configuration uses files
502 `m68k.md', `local.h', `m68k.c', `xm-local.h', `t-local', and `x-local',
503 all in the directory `config/m68k'.
505 Here is a list of configurations that have special treatment or
506 special things you must know:
509 MIL-STD-1750A processors.
511 Starting with GCC 2.6.1, the MIL-STD-1750A cross configuration no
512 longer supports the Tektronix Assembler, but instead produces
513 output for `as1750', an assembler/linker available under the GNU
514 Public License for the 1750A. Contact *kellogg@space.otn.dasa.de*
515 for more details on obtaining `as1750'. A similarly licensed
516 simulator for the 1750A is available from same address.
518 You should ignore a fatal error during the building of libgcc
519 (libgcc is not yet implemented for the 1750A.)
521 The `as1750' assembler requires the file `ms1750.inc', which is
522 found in the directory `config/1750a'.
524 GNU CC produced the same sections as the Fairchild F9450 C
528 The program code section.
531 The read/write (RAM) data section.
534 The read-only (ROM) constants section.
537 Initialization section (code to copy KREL to SREL).
539 The smallest addressable unit is 16 bits (BITS_PER_UNIT is 16).
540 This means that type `char' is represented with a 16-bit word per
541 character. The 1750A's "Load/Store Upper/Lower Byte" instructions
542 are not used by GNU CC.
545 Systems using processors that implement the DEC Alpha architecture
546 and are running the DEC Unix (OSF/1) operating system, for example
547 the DEC Alpha AXP systems. (VMS on the Alpha is not currently
548 supported by GNU CC.)
550 GNU CC writes a `.verstamp' directive to the assembler output file
551 unless it is built as a cross-compiler. It gets the version to
552 use from the system header file `/usr/include/stamp.h'. If you
553 install a new version of DEC Unix, you should rebuild GCC to pick
554 up the new version stamp.
556 Note that since the Alpha is a 64-bit architecture,
557 cross-compilers from 32-bit machines will not generate code as
558 efficient as that generated when the compiler is running on a
559 64-bit machine because many optimizations that depend on being
560 able to represent a word on the target in an integral value on the
561 host cannot be performed. Building cross-compilers on the Alpha
562 for 32-bit machines has only been tested in a few cases and may
565 `make compare' may fail on old versions of DEC Unix unless you add
566 `-save-temps' to `CFLAGS'. On these systems, the name of the
567 assembler input file is stored in the object file, and that makes
568 comparison fail if it differs between the `stage1' and `stage2'
569 compilations. The option `-save-temps' forces a fixed name to be
570 used for the assembler input file, instead of a randomly chosen
571 name in `/tmp'. Do not add `-save-temps' unless the comparisons
572 fail without that option. If you add `-save-temps', you will have
573 to manually delete the `.i' and `.s' files after each series of
576 GNU CC now supports both the native (ECOFF) debugging format used
577 by DBX and GDB and an encapsulated STABS format for use only with
578 GDB. See the discussion of the `--with-stabs' option of
579 `configure' above for more information on these formats and how to
582 There is a bug in DEC's assembler that produces incorrect line
583 numbers for ECOFF format when the `.align' directive is used. To
584 work around this problem, GNU CC will not emit such alignment
585 directives while writing ECOFF format debugging information even
586 if optimization is being performed. Unfortunately, this has the
587 very undesirable side-effect that code addresses when `-O' is
588 specified are different depending on whether or not `-g' is also
591 To avoid this behavior, specify `-gstabs+' and use GDB instead of
592 DBX. DEC is now aware of this problem with the assembler and
593 hopes to provide a fix shortly.
596 Advanced RISC Machines ARM-family processors. These are often
597 used in embedded applications. There are no standard Unix
598 configurations. This configuration corresponds to the basic
599 instruction sequences and will produce a.out format object modules.
601 You may need to make a variant of the file `arm.h' for your
602 particular configuration.
605 The ARM2 or ARM3 processor running RISC iX, Acorn's port of BSD
606 Unix. If you are running a version of RISC iX prior to 1.2 then
607 you must specify the version number during configuration. Note
608 that the assembler shipped with RISC iX does not support stabs
609 debugging information; a new version of the assembler, with stabs
610 support included, is now available from Acorn.
613 AMD Am29k-family processors. These are normally used in embedded
614 applications. There are no standard Unix configurations. This
615 configuration corresponds to AMD's standard calling sequence and
616 binary interface and is compatible with other 29k tools.
618 You may need to make a variant of the file `a29k.h' for your
619 particular configuration.
622 AMD Am29050 used in a system running a variant of BSD Unix.
625 DECstations can support three different personalities: Ultrix, DEC
626 OSF/1, and OSF/rose. To configure GCC for these platforms use the
627 following configurations:
630 Ultrix configuration.
633 Dec's version of OSF/1.
636 Open Software Foundation reference port of OSF/1 which uses
637 the OSF/rose object file format instead of ECOFF. Normally,
638 you would not select this configuration.
640 The MIPS C compiler needs to be told to increase its table size
641 for switch statements with the `-Wf,-XNg1500' option in order to
642 compile `cp/parse.c'. If you use the `-O2' optimization option,
643 you also need to use `-Olimit 3000'. Both of these options are
644 automatically generated in the `Makefile' that the shell script
645 `configure' builds. If you override the `CC' make variable and
646 use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
650 The Elxsi's C compiler has known limitations that prevent it from
651 compiling GNU C. Please contact `mrs@cygnus.com' for more details.
654 A port to the AT&T DSP1610 family of processors.
657 The calling convention and structure layout has changed in release
658 2.6. All code must be recompiled. The calling convention now
659 passes the first three arguments in function calls in registers.
660 Structures are no longer a multiple of 2 bytes.
663 There are two variants of this CPU, called 1.0 and 1.1, which have
664 different machine descriptions. You must use the right one for
665 your machine. All 7NN machines and 8N7 machines use 1.1, while
666 all other 8NN machines use 1.0.
668 The easiest way to handle this problem is to use `configure hpNNN'
669 or `configure hpNNN-hpux', where NNN is the model number of the
670 machine. Then `configure' will figure out if the machine is a 1.0
671 or 1.1. Use `uname -a' to find out the model number of your
674 `-g' does not work on HP-UX, since that system uses a peculiar
675 debugging format which GNU CC does not know about. However, `-g'
676 will work if you also use GAS and GDB in conjunction with GCC. We
677 highly recommend using GAS for all HP-PA configurations.
679 You should be using GAS-2.3 (or later) along with GDB-4.12 (or
680 later). These can be retrieved from all the traditional GNU ftp
683 Build GAS and install the resulting binary as:
685 /usr/local/lib/gcc-lib/CONFIGURATION/GCCVERSION/as
687 where CONFIGURATION is the configuration name (perhaps
688 `hpNNN-hpux') and GCCVERSION is the GNU CC version number. Do
689 this *before* starting the build process, otherwise you will get
690 errors from the HPUX assembler while building `libgcc2.a'. The
695 will create the necessary directory hierarchy so you can install
696 GAS before building GCC.
698 To enable debugging, configure GNU CC with the `--with-gnu-as'
699 option before building.
701 It has been reported that GNU CC produces invalid assembly code for
702 1.1 machines running HP-UX 8.02 when using the HP assembler.
703 Typically the errors look like this:
704 as: bug.s @line#15 [err#1060]
705 Argument 0 or 2 in FARG upper
706 - lookahead = ARGW1=FR,RTNVAL=GR
707 as: foo.s @line#28 [err#1060]
708 Argument 0 or 2 in FARG upper
709 - lookahead = ARGW1=FR
711 You can check the version of HP-UX you are running by executing
712 the command `uname -r'. If you are indeed running HP-UX 8.02 on
713 a PA and using the HP assembler then configure GCC with
717 This port is very preliminary and has many known bugs. We hope to
718 have a higher-quality port for this machine soon.
721 Use this configuration to generate a.out binaries on Linux if you
722 do not have gas/binutils version 2.5.2 or later installed. This is
723 an obsolete configuration.
726 Use this configuration to generate a.out binaries on Linux. This
727 configuration is being superseded. You must use gas/binutils
728 version 2.5.2 or later.
731 Use this configuration to generate ELF binaries on Linux. You must
732 use gas/binutils version 2.5.2 or later.
735 Compilation with RCC is recommended. Also, it may be a good idea
736 to link with GNU malloc instead of the malloc that comes with the
740 Use this configuration for SCO release 3.2 version 4.
743 It may be a good idea to link with GNU malloc instead of the
744 malloc that comes with the system.
746 In ISC version 4.1, `sed' core dumps when building `deduced.h'.
747 Use the version of `sed' from version 4.0.
750 It may be good idea to link with GNU malloc instead of the malloc
751 that comes with the system.
754 You need to use GAS version 2.1 or later, and and LD from GNU
755 binutils version 2.2 or later.
758 Go to the Berkeley universe before compiling. In addition, you
759 probably need to create a file named `string.h' containing just
760 one line: `#include <strings.h>'.
763 Sequent DYNIX/ptx 1.x.
766 Sequent DYNIX/ptx 2.x.
769 You may find that you need another version of GNU CC to begin
770 bootstrapping with, since the current version when built with the
771 system's own compiler seems to get an infinite loop compiling part
772 of `libgcc2.c'. GNU CC version 2 compiled with GNU CC (any
773 version) seems not to have this problem.
775 See *Note Sun Install::, for information on installing GNU CC on
778 `i[345]86-*-winnt3.5'
779 This version requires a GAS that has not let been released. Until
780 it is, you can get a prebuilt binary version via anonymous ftp from
781 `cs.washington.edu:pub/gnat' or `cs.nyu.edu:pub/gnat'. You must
782 also use the Microsoft header files from the Windows NT 3.5 SDK.
783 Find these on the CDROM in the `/mstools/h' directory dated
784 9/4/94. You must use a fixed version of Microsoft linker made
785 especially for NT 3.5, which is also is available on the NT 3.5
786 SDK CDROM. If you do not have this linker, can you also use the
787 linker from Visual C/C++ 1.0 or 2.0.
789 Installing GNU CC for NT builds a wrapper linker, called `ld.exe',
790 which mimics the behaviour of Unix `ld' in the specification of
791 libraries (`-L' and `-l'). `ld.exe' looks for both Unix and
792 Microsoft named libraries. For example, if you specify `-lfoo',
793 `ld.exe' will look first for `libfoo.a' and then for `foo.lib'.
795 You may install GNU CC for Windows NT in one of two ways,
796 depending on whether or not you have a Unix-like shell and various
799 1. If you do not have a Unix-like shell and few Unix-like
800 utilities, you will use a DOS style batch script called
801 `configure.bat'. Invoke it as `configure winnt' from an
802 MSDOS console window or from the program manager dialog box.
803 `configure.bat' assumes you have already installed and have
804 in your path a Unix-like `sed' program which is used to
805 create a working `Makefile' from `Makefile.in'.
807 `Makefile' uses the Microsoft Nmake program maintenance
808 utility and the Visual C/C++ V8.00 compiler to build GNU CC.
809 You need only have the utilities `sed' and `touch' to use
810 this installation method, which only automatically builds the
811 compiler itself. You must then examine what `fixinc.winnt'
812 does, edit the header files by hand and build `libgcc.a'
815 2. The second type of installation assumes you are running a
816 Unix-like shell, have a complete suite of Unix-like utilities
817 in your path, and have a previous version of GNU CC already
818 installed, either through building it via the above
819 installation method or acquiring a pre-built binary. In this
820 case, use the `configure' script in the normal fashion.
823 This is the Paragon. If you have version 1.0 of the operating
824 system, you need to take special steps to build GNU CC due to
825 peculiarities of the system. Newer system versions have no
826 problem. See the section `Installation Problems' in the GNU CC
830 LynxOS 2.2 and earlier comes with GNU CC 1.x already installed as
831 `/bin/gcc'. You should compile with this instead of `/bin/cc'.
832 You can tell GNU CC to use the GNU assembler and linker, by
833 specifying `--with-gnu-as --with-gnu-ld' when configuring. These
834 will produce COFF format object files and executables; otherwise
835 GNU CC will use the installed tools, which produce a.out format
839 HP 9000 series 200 running BSD. Note that the C compiler that
840 comes with this system cannot compile GNU CC; contact
841 `law@cs.utah.edu' to get binaries of GNU CC for bootstrapping.
844 Altos 3068. You must use the GNU assembler, linker and debugger.
845 Also, you must fix a kernel bug. Details in the file
849 AT&T 3b1, a.k.a. 7300 PC. Special procedures are needed to
850 compile GNU CC with this machine's standard C compiler, due to
851 bugs in that compiler. You can bootstrap it more easily with
852 previous versions of GNU CC if you have them.
854 Installing GNU CC on the 3b1 is difficult if you do not already
855 have GNU CC running, due to bugs in the installed C compiler.
856 However, the following procedure might work. We are unable to
859 1. Comment out the `#include "config.h"' line on line 37 of
860 `cccp.c' and do `make cpp'. This makes a preliminary version
863 2. Save the old `/lib/cpp' and copy the preliminary GNU cpp to
866 3. Undo your change in `cccp.c', or reinstall the original
867 version, and do `make cpp' again.
869 4. Copy this final version of GNU cpp into `/lib/cpp'.
871 5. Replace every occurrence of `obstack_free' in the file
872 `tree.c' with `_obstack_free'.
874 6. Run `make' to get the first-stage GNU CC.
876 7. Reinstall the original version of `/lib/cpp'.
878 8. Now you can compile GNU CC with itself and install it in the
882 Bull DPX/2 series 200 and 300 with BOS-2.00.45 up to BOS-2.01. GNU
883 CC works either with native assembler or GNU assembler. You can use
884 GNU assembler with native coff generation by providing
885 `--with-gnu-as' to the configure script or use GNU assembler with
886 dbx-in-coff encapsulation by providing `--with-gnu-as --stabs'.
887 For any problem with native assembler or for availability of the
888 DPX/2 port of GAS, contact `F.Pierresteguy@frcl.bull.fr'.
891 Use `configure unos' for building on Unos.
893 The Unos assembler is named `casm' instead of `as'. For some
894 strange reason linking `/bin/as' to `/bin/casm' changes the
895 behavior, and does not work. So, when installing GNU CC, you
896 should install the following script as `as' in the subdirectory
897 where the passes of GCC are installed:
902 The default Unos library is named `libunos.a' instead of `libc.a'.
903 To allow GNU CC to function, either change all references to
904 `-lc' in `gcc.c' to `-lunos' or link `/lib/libc.a' to
907 When compiling GNU CC with the standard compiler, to overcome bugs
908 in the support of `alloca', do not use `-O' when making stage 2.
909 Then use the stage 2 compiler with `-O' to make the stage 3
910 compiler. This compiler will have the same characteristics as the
911 usual stage 2 compiler on other systems. Use it to make a stage 4
912 compiler and compare that with stage 3 to verify proper
915 (Perhaps simply defining `ALLOCA' in `x-crds' as described in the
916 comments there will make the above paragraph superfluous. Please
917 inform us of whether this works.)
919 Unos uses memory segmentation instead of demand paging, so you
920 will need a lot of memory. 5 Mb is barely enough if no other
921 tasks are running. If linking `cc1' fails, try putting the object
922 files into a library and linking from that library.
925 HP 9000 series 300 or 400 running HP-UX. HP-UX version 8.0 has a
926 bug in the assembler that prevents compilation of GNU CC. To fix
927 it, get patch PHCO_4484 from HP.
929 In addition, if you wish to use gas `--with-gnu-as' you must use
930 gas version 2.1 or later, and you must use the GNU linker version
931 2.1 or later. Earlier versions of gas relied upon a program which
932 converted the gas output into the native HP/UX format, but that
933 program has not been kept up to date. gdb does not understand
934 that native HP/UX format, so you must use gas if you wish to use
938 Sun 3. We do not provide a configuration file to use the Sun FPA
939 by default, because programs that establish signal handlers for
940 floating point traps inherently cannot work with the FPA.
942 See *Note Sun Install::, for information on installing GNU CC on
946 Motorola m88k running the AT&T/Unisoft/Motorola V.3 reference port.
947 These systems tend to use the Green Hills C, revision 1.8.5, as the
948 standard C compiler. There are apparently bugs in this compiler
949 that result in object files differences between stage 2 and stage
950 3. If this happens, make the stage 4 compiler and compare it to
951 the stage 3 compiler. If the stage 3 and stage 4 object files are
952 identical, this suggests you encountered a problem with the
953 standard C compiler; the stage 3 and 4 compilers may be usable.
955 It is best, however, to use an older version of GNU CC for
956 bootstrapping if you have one.
959 Motorola m88k running DG/UX. To build 88open BCS native or cross
960 compilers on DG/UX, specify the configuration name as
961 `m88k-*-dguxbcs' and build in the 88open BCS software development
962 environment. To build ELF native or cross compilers on DG/UX,
963 specify `m88k-*-dgux' and build in the DG/UX ELF development
964 environment. You set the software development environment by
965 issuing `sde-target' command and specifying either `m88kbcs' or
966 `m88kdguxelf' as the operand.
968 If you do not specify a configuration name, `configure' guesses the
969 configuration based on the current software development
972 `m88k-tektronix-sysv3'
973 Tektronix XD88 running UTekV 3.2e. Do not turn on optimization
974 while building stage1 if you bootstrap with the buggy Green Hills
975 compiler. Also, The bundled LAI System V NFS is buggy so if you
976 build in an NFS mounted directory, start from a fresh reboot, or
977 avoid NFS all together. Otherwise you may have trouble getting
978 clean comparisons between stages.
981 MIPS machines running the MIPS operating system in BSD mode. It's
982 possible that some old versions of the system lack the functions
983 `memcpy', `memcmp', and `memset'. If your system lacks these, you
984 must remove or undo the definition of `TARGET_MEM_FUNCTIONS' in
987 The MIPS C compiler needs to be told to increase its table size
988 for switch statements with the `-Wf,-XNg1500' option in order to
989 compile `cp/parse.c'. If you use the `-O2' optimization option,
990 you also need to use `-Olimit 3000'. Both of these options are
991 automatically generated in the `Makefile' that the shell script
992 `configure' builds. If you override the `CC' make variable and
993 use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
997 The MIPS C compiler needs to be told to increase its table size
998 for switch statements with the `-Wf,-XNg1500' option in order to
999 compile `cp/parse.c'. If you use the `-O2' optimization option,
1000 you also need to use `-Olimit 3000'. Both of these options are
1001 automatically generated in the `Makefile' that the shell script
1002 `configure' builds. If you override the `CC' make variable and
1003 use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
1006 MIPS computers running RISC-OS can support four different
1007 personalities: default, BSD 4.3, System V.3, and System V.4 (older
1008 versions of RISC-OS don't support V.4). To configure GCC for
1009 these platforms use the following configurations:
1011 `mips-mips-riscos`rev''
1012 Default configuration for RISC-OS, revision `rev'.
1014 `mips-mips-riscos`rev'bsd'
1015 BSD 4.3 configuration for RISC-OS, revision `rev'.
1017 `mips-mips-riscos`rev'sysv4'
1018 System V.4 configuration for RISC-OS, revision `rev'.
1020 `mips-mips-riscos`rev'sysv'
1021 System V.3 configuration for RISC-OS, revision `rev'.
1023 The revision `rev' mentioned above is the revision of RISC-OS to
1024 use. You must reconfigure GCC when going from a RISC-OS revision
1025 4 to RISC-OS revision 5. This has the effect of avoiding a linker
1029 In order to compile GCC on an SGI running IRIX 4, the "c.hdr.lib"
1030 option must be installed from the CD-ROM supplied from Silicon
1031 Graphics. This is found on the 2nd CD in release 4.0.1.
1033 In order to compile GCC on an SGI running IRIX 5, the
1034 "compiler_dev.hdr" subsystem must be installed from the IDO CD-ROM
1035 supplied by Silicon Graphics.
1037 `make compare' may fail on version 5 of IRIX unless you add
1038 `-save-temps' to `CFLAGS'. On these systems, the name of the
1039 assembler input file is stored in the object file, and that makes
1040 comparison fail if it differs between the `stage1' and `stage2'
1041 compilations. The option `-save-temps' forces a fixed name to be
1042 used for the assembler input file, instead of a randomly chosen
1043 name in `/tmp'. Do not add `-save-temps' unless the comparisons
1044 fail without that option. If you do you `-save-temps', you will
1045 have to manually delete the `.i' and `.s' files after each series
1048 The MIPS C compiler needs to be told to increase its table size
1049 for switch statements with the `-Wf,-XNg1500' option in order to
1050 compile `cp/parse.c'. If you use the `-O2' optimization option,
1051 you also need to use `-Olimit 3000'. Both of these options are
1052 automatically generated in the `Makefile' that the shell script
1053 `configure' builds. If you override the `CC' make variable and
1054 use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
1057 On Irix version 4.0.5F, and perhaps on some other versions as well,
1058 there is an assembler bug that reorders instructions incorrectly.
1059 To work around it, specify the target configuration
1060 `mips-sgi-irix4loser'. This configuration inhibits assembler
1063 In a compiler configured with target `mips-sgi-irix4', you can turn
1064 off assembler optimization by using the `-noasmopt' option. This
1065 compiler option passes the option `-O0' to the assembler, to
1068 The `-noasmopt' option can be useful for testing whether a problem
1069 is due to erroneous assembler reordering. Even if a problem does
1070 not go away with `-noasmopt', it may still be due to assembler
1071 reordering--perhaps GNU CC itself was miscompiled as a result.
1073 To enable debugging under Irix 5, you must use GNU as 2.5 or later,
1074 and use the `--with-gnu-as' configure option when configuring gcc.
1075 GNU as is distributed as part of the binutils package.
1078 Sony MIPS NEWS. This works in NEWSOS 5.0.1, but not in 5.0.2
1079 (which uses ELF instead of COFF). Support for 5.0.2 will probably
1080 be provided soon by volunteers. In particular, the linker does
1081 not like the code generated by GCC when shared libraries are
1085 Encore ns32000 system. Encore systems are supported only under
1089 National Semiconductor ns32000 system. Genix has bugs in `alloca'
1090 and `malloc'; you must get the compiled versions of these from GNU
1094 Go to the Berkeley universe before compiling. In addition, you
1095 probably need to create a file named `string.h' containing just
1096 one line: `#include <strings.h>'.
1099 UTEK ns32000 system ("merlin"). The C compiler that comes with
1100 this system cannot compile GNU CC; contact `tektronix!reed!mason'
1101 to get binaries of GNU CC for bootstrapping.
1105 The only operating systems supported for the IBM RT PC are AOS and
1106 MACH. GNU CC does not support AIX running on the RT. We
1107 recommend you compile GNU CC with an earlier version of itself; if
1108 you compile GNU CC with `hc', the Metaware compiler, it will work,
1109 but you will get mismatches between the stage 2 and stage 3
1110 compilers in various files. These errors are minor differences in
1111 some floating-point constants and can be safely ignored; the stage
1112 3 compiler is correct.
1116 Various early versions of each release of the IBM XLC compiler
1117 will not bootstrap GNU CC. Symptoms include differences between
1118 the stage2 and stage3 object files, and errors when compiling
1119 `libgcc.a' or `enquire'. Known problematic releases include:
1120 xlc-1.2.1.8, xlc-1.3.0.0 (distributed with AIX 3.2.5), and
1121 xlc-1.3.0.19. Both xlc-1.2.1.28 and xlc-1.3.0.24 (PTF 432238) are
1122 known to produce working versions of GNU CC, but most other recent
1123 releases correctly bootstrap GNU CC. Also, releases of AIX prior
1124 to AIX 3.2.4 include a version of the IBM assembler which does not
1125 accept debugging directives: assembler updates are available as
1126 PTFs. Also, if you are using AIX 3.2.5 or greater and the GNU
1127 assembler, you must have a version modified after October 16th,
1128 1995 in order for the GNU C compiler to build. See the file
1129 `README.RS6000' for more details on of these problems.
1131 GNU CC does not yet support the 64-bit PowerPC instructions.
1133 Objective C does not work on this architecture because it makes
1134 assumptions that are incompatible with the calling conventions.
1136 AIX on the RS/6000 provides support (NLS) for environments outside
1137 of the United States. Compilers and assemblers use NLS to support
1138 locale-specific representations of various objects including
1139 floating-point numbers ("." vs "," for separating decimal
1140 fractions). There have been problems reported where the library
1141 linked with GNU CC does not produce the same floating-point
1142 formats that the assembler accepts. If you have this problem, set
1143 the LANG environment variable to "C" or "En_US".
1145 Due to changes in the way that GNU CC invokes the binder (linker)
1146 for AIX 4.1, you may now receive warnings of duplicate symbols
1147 from the link step that were not reported before. The assembly
1148 files generated by GNU CC for AIX have always included multiple
1149 symbol definitions for certain global variable and function
1150 declarations in the original program. The warnings should not
1151 prevent the linker from producing a correct library or runnable
1156 PowerPC system in big endian mode, running System V.4.
1158 This configuration is currently under development.
1161 Embedded PowerPC system in big endian mode with -mcall-aix
1162 selected as the default. This system is currently under
1166 Embedded PowerPC system in big endian mode for use in running
1167 under the PSIM simulator. This system is currently under
1171 Embedded PowerPC system in big endian mode.
1173 This configuration is currently under development.
1177 PowerPC system in little endian mode, running System V.4.
1179 This configuration is currently under development.
1182 Embedded PowerPC system in little endian mode.
1184 This system is currently under development.
1186 `powerpcle-*-eabisim'
1187 Embedded PowerPC system in little endian mode for use in running
1188 under the PSIM simulator.
1190 This system is currently under development.
1193 Embedded PowerPC system in little endian mode.
1195 This configuration is currently under development.
1198 Don't try compiling with Vax C (`vcc'). It produces incorrect code
1199 in some cases (for example, when `alloca' is used).
1201 Meanwhile, compiling `cp/parse.c' with pcc does not work because of
1202 an internal table size limitation in that compiler. To avoid this
1203 problem, compile just the GNU C compiler first, and use it to
1204 recompile building all the languages that you want to run.
1207 See *Note Sun Install::, for information on installing GNU CC on
1211 See *Note VMS Install::, for details on how to install GNU CC on
1215 These computers are also known as the 3b2, 3b5, 3b20 and other
1216 similar names. (However, the 3b1 is actually a 68000; see *Note
1219 Don't use `-g' when compiling with the system's compiler. The
1220 system's linker seems to be unable to handle such a large program
1221 with debugging information.
1223 The system's compiler runs out of capacity when compiling `stmt.c'
1224 in GNU CC. You can work around this by building `cpp' in GNU CC
1225 first, then use that instead of the system's preprocessor with the
1226 system's C compiler to compile `stmt.c'. Here is how:
1228 mv /lib/cpp /lib/cpp.att
1230 echo '/lib/cpp.gnu -traditional ${1+"$@"}' > /lib/cpp
1233 The system's compiler produces bad code for some of the GNU CC
1234 optimization files. So you must build the stage 2 compiler without
1235 optimization. Then build a stage 3 compiler with optimization.
1236 That executable should work. Here are the necessary commands:
1238 make LANGUAGES=c CC=stage1/xgcc CFLAGS="-Bstage1/ -g"
1240 make CC=stage2/xgcc CFLAGS="-Bstage2/ -g -O"
1242 You may need to raise the ULIMIT setting to build a C++ compiler,
1243 as the file `cc1plus' is larger than one megabyte.
1245 Compilation in a Separate Directory
1246 ===================================
1248 If you wish to build the object files and executables in a directory
1249 other than the one containing the source files, here is what you must
1252 1. Make sure you have a version of Make that supports the `VPATH'
1253 feature. (GNU Make supports it, as do Make versions on most BSD
1256 2. If you have ever run `configure' in the source directory, you must
1257 undo the configuration. Do this by running:
1261 3. Go to the directory in which you want to build the compiler before
1262 running `configure':
1267 On systems that do not support symbolic links, this directory must
1268 be on the same file system as the source code directory.
1270 4. Specify where to find `configure' when you run it:
1272 ../gcc/configure ...
1274 This also tells `configure' where to find the compiler sources;
1275 `configure' takes the directory from the file name that was used to
1276 invoke it. But if you want to be sure, you can specify the source
1277 directory with the `--srcdir' option, like this:
1279 ../gcc/configure --srcdir=../gcc OTHER OPTIONS
1281 The directory you specify with `--srcdir' need not be the same as
1282 the one that `configure' is found in.
1284 Now, you can run `make' in that directory. You need not repeat the
1285 configuration steps shown above, when ordinary source files change. You
1286 must, however, run `configure' again when the configuration files
1287 change, if your system does not support symbolic links.
1289 Building and Installing a Cross-Compiler
1290 ========================================
1292 GNU CC can function as a cross-compiler for many machines, but not
1295 * Cross-compilers for the Mips as target using the Mips assembler
1296 currently do not work, because the auxiliary programs
1297 `mips-tdump.c' and `mips-tfile.c' can't be compiled on anything
1298 but a Mips. It does work to cross compile for a Mips if you use
1299 the GNU assembler and linker.
1301 * Cross-compilers between machines with different floating point
1302 formats have not all been made to work. GNU CC now has a floating
1303 point emulator with which these can work, but each target machine
1304 description needs to be updated to take advantage of it.
1306 * Cross-compilation between machines of different word sizes is
1307 somewhat problematic and sometimes does not work.
1309 Since GNU CC generates assembler code, you probably need a
1310 cross-assembler that GNU CC can run, in order to produce object files.
1311 If you want to link on other than the target machine, you need a
1312 cross-linker as well. You also need header files and libraries suitable
1313 for the target machine that you can install on the host machine.
1315 Steps of Cross-Compilation
1316 --------------------------
1318 To compile and run a program using a cross-compiler involves several
1321 * Run the cross-compiler on the host machine to produce assembler
1322 files for the target machine. This requires header files for the
1325 * Assemble the files produced by the cross-compiler. You can do this
1326 either with an assembler on the target machine, or with a
1327 cross-assembler on the host machine.
1329 * Link those files to make an executable. You can do this either
1330 with a linker on the target machine, or with a cross-linker on the
1331 host machine. Whichever machine you use, you need libraries and
1332 certain startup files (typically `crt....o') for the target
1335 It is most convenient to do all of these steps on the same host
1336 machine, since then you can do it all with a single invocation of GNU
1337 CC. This requires a suitable cross-assembler and cross-linker. For
1338 some targets, the GNU assembler and linker are available.
1340 Configuring a Cross-Compiler
1341 ----------------------------
1343 To build GNU CC as a cross-compiler, you start out by running
1344 `configure'. Use the `--target=TARGET' to specify the target type. If
1345 `configure' was unable to correctly identify the system you are running
1346 on, also specify the `--build=BUILD' option. For example, here is how
1347 to configure for a cross-compiler that produces code for an HP 68030
1348 system running BSD on a system that `configure' can correctly identify:
1350 ./configure --target=m68k-hp-bsd4.3
1352 Tools and Libraries for a Cross-Compiler
1353 ----------------------------------------
1355 If you have a cross-assembler and cross-linker available, you should
1356 install them now. Put them in the directory `/usr/local/TARGET/bin'.
1357 Here is a table of the tools you should put in this directory:
1360 This should be the cross-assembler.
1363 This should be the cross-linker.
1366 This should be the cross-archiver: a program which can manipulate
1367 archive files (linker libraries) in the target machine's format.
1370 This should be a program to construct a symbol table in an archive
1373 The installation of GNU CC will find these programs in that
1374 directory, and copy or link them to the proper place to for the
1375 cross-compiler to find them when run later.
1377 The easiest way to provide these files is to build the Binutils
1378 package and GAS. Configure them with the same `--host' and `--target'
1379 options that you use for configuring GNU CC, then build and install
1380 them. They install their executables automatically into the proper
1381 directory. Alas, they do not support all the targets that GNU CC
1384 If you want to install libraries to use with the cross-compiler,
1385 such as a standard C library, put them in the directory
1386 `/usr/local/TARGET/lib'; installation of GNU CC copies all all the
1387 files in that subdirectory into the proper place for GNU CC to find
1388 them and link with them. Here's an example of copying some libraries
1389 from a target machine:
1392 lcd /usr/local/TARGET/lib
1400 The precise set of libraries you'll need, and their locations on the
1401 target machine, vary depending on its operating system.
1403 Many targets require "start files" such as `crt0.o' and `crtn.o'
1404 which are linked into each executable; these too should be placed in
1405 `/usr/local/TARGET/lib'. There may be several alternatives for
1406 `crt0.o', for use with profiling or other compilation options. Check
1407 your target's definition of `STARTFILE_SPEC' to find out what start
1408 files it uses. Here's an example of copying these files from a target
1412 lcd /usr/local/TARGET/lib
1420 `libgcc.a' and Cross-Compilers
1421 ------------------------------
1423 Code compiled by GNU CC uses certain runtime support functions
1424 implicitly. Some of these functions can be compiled successfully with
1425 GNU CC itself, but a few cannot be. These problem functions are in the
1426 source file `libgcc1.c'; the library made from them is called
1429 When you build a native compiler, these functions are compiled with
1430 some other compiler-the one that you use for bootstrapping GNU CC.
1431 Presumably it knows how to open code these operations, or else knows how
1432 to call the run-time emulation facilities that the machine comes with.
1433 But this approach doesn't work for building a cross-compiler. The
1434 compiler that you use for building knows about the host system, not the
1437 So, when you build a cross-compiler you have to supply a suitable
1438 library `libgcc1.a' that does the job it is expected to do.
1440 To compile `libgcc1.c' with the cross-compiler itself does not work.
1441 The functions in this file are supposed to implement arithmetic
1442 operations that GNU CC does not know how to open code for your target
1443 machine. If these functions are compiled with GNU CC itself, they will
1444 compile into infinite recursion.
1446 On any given target, most of these functions are not needed. If GNU
1447 CC can open code an arithmetic operation, it will not call these
1448 functions to perform the operation. It is possible that on your target
1449 machine, none of these functions is needed. If so, you can supply an
1450 empty library as `libgcc1.a'.
1452 Many targets need library support only for multiplication and
1453 division. If you are linking with a library that contains functions for
1454 multiplication and division, you can tell GNU CC to call them directly
1455 by defining the macros `MULSI3_LIBCALL', and the like. These macros
1456 need to be defined in the target description macro file. For some
1457 targets, they are defined already. This may be sufficient to avoid the
1458 need for libgcc1.a; if so, you can supply an empty library.
1460 Some targets do not have floating point instructions; they need other
1461 functions in `libgcc1.a', which do floating arithmetic. Recent
1462 versions of GNU CC have a file which emulates floating point. With a
1463 certain amount of work, you should be able to construct a floating
1464 point emulator that can be used as `libgcc1.a'. Perhaps future
1465 versions will contain code to do this automatically and conveniently.
1466 That depends on whether someone wants to implement it.
1468 Some embedded targets come with all the necessary `libgcc1.a'
1469 routines written in C or assembler. These targets build `libgcc1.a'
1470 automatically and you do not need to do anything special for them.
1471 Other embedded targets do not need any `libgcc1.a' routines since all
1472 the necessary operations are supported by the hardware.
1474 If your target system has another C compiler, you can configure GNU
1475 CC as a native compiler on that machine, build just `libgcc1.a' with
1476 `make libgcc1.a' on that machine, and use the resulting file with the
1477 cross-compiler. To do this, execute the following on the target
1481 ./configure --host=sparc --target=sun3
1484 And then this on the host machine:
1492 Another way to provide the functions you need in `libgcc1.a' is to
1493 define the appropriate `perform_...' macros for those functions. If
1494 these definitions do not use the C arithmetic operators that they are
1495 meant to implement, you should be able to compile them with the
1496 cross-compiler you are building. (If these definitions already exist
1497 for your target file, then you are all set.)
1499 To build `libgcc1.a' using the perform macros, use
1500 `LIBGCC1=libgcc1.a OLDCC=./xgcc' when building the compiler.
1501 Otherwise, you should place your replacement library under the name
1502 `libgcc1.a' in the directory in which you will build the
1503 cross-compiler, before you run `make'.
1505 Cross-Compilers and Header Files
1506 --------------------------------
1508 If you are cross-compiling a standalone program or a program for an
1509 embedded system, then you may not need any header files except the few
1510 that are part of GNU CC (and those of your program). However, if you
1511 intend to link your program with a standard C library such as `libc.a',
1512 then you probably need to compile with the header files that go with
1513 the library you use.
1515 The GNU C compiler does not come with these files, because (1) they
1516 are system-specific, and (2) they belong in a C library, not in a
1519 If the GNU C library supports your target machine, then you can get
1520 the header files from there (assuming you actually use the GNU library
1521 when you link your program).
1523 If your target machine comes with a C compiler, it probably comes
1524 with suitable header files also. If you make these files accessible
1525 from the host machine, the cross-compiler can use them also.
1527 Otherwise, you're on your own in finding header files to use when
1530 When you have found suitable header files, put them in
1531 `/usr/local/TARGET/include', before building the cross compiler. Then
1532 installation will run fixincludes properly and install the corrected
1533 versions of the header files where the compiler will use them.
1535 Provide the header files before you build the cross-compiler, because
1536 the build stage actually runs the cross-compiler to produce parts of
1537 `libgcc.a'. (These are the parts that *can* be compiled with GNU CC.)
1538 Some of them need suitable header files.
1540 Here's an example showing how to copy the header files from a target
1541 machine. On the target machine, do this:
1543 (cd /usr/include; tar cf - .) > tarfile
1545 Then, on the host machine, do this:
1548 lcd /usr/local/TARGET/include
1553 Actually Building the Cross-Compiler
1554 ------------------------------------
1556 Now you can proceed just as for compiling a single-machine compiler
1557 through the step of building stage 1. If you have not provided some
1558 sort of `libgcc1.a', then compilation will give up at the point where
1559 it needs that file, printing a suitable error message. If you do
1560 provide `libgcc1.a', then building the compiler will automatically
1561 compile and link a test program called `libgcc1-test'; if you get
1562 errors in the linking, it means that not all of the necessary routines
1563 in `libgcc1.a' are available.
1565 You must provide the header file `float.h'. One way to do this is
1566 to compile `enquire' and run it on your target machine. The job of
1567 `enquire' is to run on the target machine and figure out by experiment
1568 the nature of its floating point representation. `enquire' records its
1569 findings in the header file `float.h'. If you can't produce this file
1570 by running `enquire' on the target machine, then you will need to come
1571 up with a suitable `float.h' in some other way (or else, avoid using it
1574 Do not try to build stage 2 for a cross-compiler. It doesn't work to
1575 rebuild GNU CC as a cross-compiler using the cross-compiler, because
1576 that would produce a program that runs on the target machine, not on the
1577 host. For example, if you compile a 386-to-68030 cross-compiler with
1578 itself, the result will not be right either for the 386 (because it was
1579 compiled into 68030 code) or for the 68030 (because it was configured
1580 for a 386 as the host). If you want to compile GNU CC into 68030 code,
1581 whether you compile it on a 68030 or with a cross-compiler on a 386, you
1582 must specify a 68030 as the host when you configure it.
1584 To install the cross-compiler, use `make install', as usual.
1586 Installing GNU CC on the Sun
1587 ============================
1589 On Solaris (version 2.1), do not use the linker or other tools in
1590 `/usr/ucb' to build GNU CC. Use `/usr/ccs/bin'.
1592 Make sure the environment variable `FLOAT_OPTION' is not set when
1593 you compile `libgcc.a'. If this option were set to `f68881' when
1594 `libgcc.a' is compiled, the resulting code would demand to be linked
1595 with a special startup file and would not link properly without special
1598 There is a bug in `alloca' in certain versions of the Sun library.
1599 To avoid this bug, install the binaries of GNU CC that were compiled by
1600 GNU CC. They use `alloca' as a built-in function and never the one in
1603 Some versions of the Sun compiler crash when compiling GNU CC. The
1604 problem is a segmentation fault in cpp. This problem seems to be due to
1605 the bulk of data in the environment variables. You may be able to avoid
1606 it by using the following command to compile GNU CC with Sun CC:
1608 make CC="TERMCAP=x OBJS=x LIBFUNCS=x STAGESTUFF=x cc"
1610 Installing GNU CC on VMS
1611 ========================
1613 The VMS version of GNU CC is distributed in a backup saveset
1614 containing both source code and precompiled binaries.
1616 To install the `gcc' command so you can use the compiler easily, in
1617 the same manner as you use the VMS C compiler, you must install the VMS
1618 CLD file for GNU CC as follows:
1620 1. Define the VMS logical names `GNU_CC' and `GNU_CC_INCLUDE' to
1621 point to the directories where the GNU CC executables
1622 (`gcc-cpp.exe', `gcc-cc1.exe', etc.) and the C include files are
1623 kept respectively. This should be done with the commands:
1625 $ assign /system /translation=concealed -
1627 $ assign /system /translation=concealed -
1628 disk:[gcc.include.] gnu_cc_include
1630 with the appropriate disk and directory names. These commands can
1631 be placed in your system startup file so they will be executed
1632 whenever the machine is rebooted. You may, if you choose, do this
1633 via the `GCC_INSTALL.COM' script in the `[GCC]' directory.
1635 2. Install the `GCC' command with the command line:
1637 $ set command /table=sys$common:[syslib]dcltables -
1638 /output=sys$common:[syslib]dcltables gnu_cc:[000000]gcc
1639 $ install replace sys$common:[syslib]dcltables
1641 3. To install the help file, do the following:
1643 $ library/help sys$library:helplib.hlb gcc.hlp
1645 Now you can invoke the compiler with a command like `gcc /verbose
1646 file.c', which is equivalent to the command `gcc -v -c file.c' in
1649 If you wish to use GNU C++ you must first install GNU CC, and then
1650 perform the following steps:
1652 1. Define the VMS logical name `GNU_GXX_INCLUDE' to point to the
1653 directory where the preprocessor will search for the C++ header
1654 files. This can be done with the command:
1656 $ assign /system /translation=concealed -
1657 disk:[gcc.gxx_include.] gnu_gxx_include
1659 with the appropriate disk and directory name. If you are going to
1660 be using libg++, this is where the libg++ install procedure will
1661 install the libg++ header files.
1663 2. Obtain the file `gcc-cc1plus.exe', and place this in the same
1664 directory that `gcc-cc1.exe' is kept.
1666 The GNU C++ compiler can be invoked with a command like `gcc /plus
1667 /verbose file.cc', which is equivalent to the command `g++ -v -c
1670 We try to put corresponding binaries and sources on the VMS
1671 distribution tape. But sometimes the binaries will be from an older
1672 version than the sources, because we don't always have time to update
1673 them. (Use the `/version' option to determine the version number of
1674 the binaries and compare it with the source file `version.c' to tell
1675 whether this is so.) In this case, you should use the binaries you get
1676 to recompile the sources. If you must recompile, here is how:
1678 1. Execute the command procedure `vmsconfig.com' to set up the files
1679 `tm.h', `config.h', `aux-output.c', and `md.', and to create files
1680 `tconfig.h' and `hconfig.h'. This procedure also creates several
1681 linker option files used by `make-cc1.com' and a data file used by
1686 2. Setup the logical names and command tables as defined above. In
1687 addition, define the VMS logical name `GNU_BISON' to point at the
1688 to the directories where the Bison executable is kept. This
1689 should be done with the command:
1691 $ assign /system /translation=concealed -
1692 disk:[bison.] gnu_bison
1694 You may, if you choose, use the `INSTALL_BISON.COM' script in the
1695 `[BISON]' directory.
1697 3. Install the `BISON' command with the command line:
1699 $ set command /table=sys$common:[syslib]dcltables -
1700 /output=sys$common:[syslib]dcltables -
1701 gnu_bison:[000000]bison
1702 $ install replace sys$common:[syslib]dcltables
1704 4. Type `@make-gcc' to recompile everything (alternatively, submit
1705 the file `make-gcc.com' to a batch queue). If you wish to build
1706 the GNU C++ compiler as well as the GNU CC compiler, you must
1707 first edit `make-gcc.com' and follow the instructions that appear
1710 5. In order to use GCC, you need a library of functions which GCC
1711 compiled code will call to perform certain tasks, and these
1712 functions are defined in the file `libgcc2.c'. To compile this
1713 you should use the command procedure `make-l2.com', which will
1714 generate the library `libgcc2.olb'. `libgcc2.olb' should be built
1715 using the compiler built from the same distribution that
1716 `libgcc2.c' came from, and `make-gcc.com' will automatically do
1717 all of this for you.
1719 To install the library, use the following commands:
1721 $ library gnu_cc:[000000]gcclib/delete=(new,eprintf)
1722 $ library gnu_cc:[000000]gcclib/delete=L_*
1723 $ library libgcc2/extract=*/output=libgcc2.obj
1724 $ library gnu_cc:[000000]gcclib libgcc2.obj
1726 The first command simply removes old modules that will be replaced
1727 with modules from `libgcc2' under different module names. The
1728 modules `new' and `eprintf' may not actually be present in your
1729 `gcclib.olb'--if the VMS librarian complains about those modules
1730 not being present, simply ignore the message and continue on with
1731 the next command. The second command removes the modules that
1732 came from the previous version of the library `libgcc2.c'.
1734 Whenever you update the compiler on your system, you should also
1735 update the library with the above procedure.
1737 6. You may wish to build GCC in such a way that no files are written
1738 to the directory where the source files reside. An example would
1739 be the when the source files are on a read-only disk. In these
1740 cases, execute the following DCL commands (substituting your
1743 $ assign dua0:[gcc.build_dir.]/translation=concealed, -
1744 dua1:[gcc.source_dir.]/translation=concealed gcc_build
1745 $ set default gcc_build:[000000]
1747 where the directory `dua1:[gcc.source_dir]' contains the source
1748 code, and the directory `dua0:[gcc.build_dir]' is meant to contain
1749 all of the generated object files and executables. Once you have
1750 done this, you can proceed building GCC as described above. (Keep
1751 in mind that `gcc_build' is a rooted logical name, and thus the
1752 device names in each element of the search list must be an actual
1753 physical device name rather than another rooted logical name).
1755 7. *If you are building GNU CC with a previous version of GNU CC, you
1756 also should check to see that you have the newest version of the
1757 assembler*. In particular, GNU CC version 2 treats global constant
1758 variables slightly differently from GNU CC version 1, and GAS
1759 version 1.38.1 does not have the patches required to work with GCC
1760 version 2. If you use GAS 1.38.1, then `extern const' variables
1761 will not have the read-only bit set, and the linker will generate
1762 warning messages about mismatched psect attributes for these
1763 variables. These warning messages are merely a nuisance, and can
1766 If you are compiling with a version of GNU CC older than 1.33,
1767 specify `/DEFINE=("inline=")' as an option in all the
1768 compilations. This requires editing all the `gcc' commands in
1769 `make-cc1.com'. (The older versions had problems supporting
1770 `inline'.) Once you have a working 1.33 or newer GNU CC, you can
1771 change this file back.
1773 8. If you want to build GNU CC with the VAX C compiler, you will need
1774 to make minor changes in `make-cccp.com' and `make-cc1.com' to
1775 choose alternate definitions of `CC', `CFLAGS', and `LIBS'. See
1776 comments in those files. However, you must also have a working
1777 version of the GNU assembler (GNU as, aka GAS) as it is used as
1778 the back-end for GNU CC to produce binary object modules and is
1779 not included in the GNU CC sources. GAS is also needed to compile
1780 `libgcc2' in order to build `gcclib' (see above); `make-l2.com'
1781 expects to be able to find it operational in
1782 `gnu_cc:[000000]gnu-as.exe'.
1784 To use GNU CC on VMS, you need the VMS driver programs `gcc.exe',
1785 `gcc.com', and `gcc.cld'. They are distributed with the VMS
1786 binaries (`gcc-vms') rather than the GNU CC sources. GAS is also
1787 included in `gcc-vms', as is Bison.
1789 Once you have successfully built GNU CC with VAX C, you should use
1790 the resulting compiler to rebuild itself. Before doing this, be
1791 sure to restore the `CC', `CFLAGS', and `LIBS' definitions in
1792 `make-cccp.com' and `make-cc1.com'. The second generation
1793 compiler will be able to take advantage of many optimizations that
1794 must be suppressed when building with other compilers.
1796 Under previous versions of GNU CC, the generated code would
1797 occasionally give strange results when linked with the sharable
1798 `VAXCRTL' library. Now this should work.
1800 Even with this version, however, GNU CC itself should not be linked
1801 with the sharable `VAXCRTL'. The version of `qsort' in `VAXCRTL' has a
1802 bug (known to be present in VMS versions V4.6 through V5.5) which
1803 causes the compiler to fail.
1805 The executables are generated by `make-cc1.com' and `make-cccp.com'
1806 use the object library version of `VAXCRTL' in order to make use of the
1807 `qsort' routine in `gcclib.olb'. If you wish to link the compiler
1808 executables with the shareable image version of `VAXCRTL', you should
1809 edit the file `tm.h' (created by `vmsconfig.com') to define the macro
1812 `QSORT_WORKAROUND' is always defined when GNU CC is compiled with
1813 VAX C, to avoid a problem in case `gcclib.olb' is not yet available.
1818 Many target systems do not have support in the assembler and linker
1819 for "constructors"--initialization functions to be called before the
1820 official "start" of `main'. On such systems, GNU CC uses a utility
1821 called `collect2' to arrange to call these functions at start time.
1823 The program `collect2' works by linking the program once and looking
1824 through the linker output file for symbols with particular names
1825 indicating they are constructor functions. If it finds any, it creates
1826 a new temporary `.c' file containing a table of them, compiles it, and
1827 links the program a second time including that file.
1829 The actual calls to the constructors are carried out by a subroutine
1830 called `__main', which is called (automatically) at the beginning of
1831 the body of `main' (provided `main' was compiled with GNU CC). Calling
1832 `__main' is necessary, even when compiling C code, to allow linking C
1833 and C++ object code together. (If you use `-nostdlib', you get an
1834 unresolved reference to `__main', since it's defined in the standard
1835 GCC library. Include `-lgcc' at the end of your compiler command line
1836 to resolve this reference.)
1838 The program `collect2' is installed as `ld' in the directory where
1839 the passes of the compiler are installed. When `collect2' needs to
1840 find the *real* `ld', it tries the following file names:
1842 * `real-ld' in the directories listed in the compiler's search
1845 * `real-ld' in the directories listed in the environment variable
1848 * The file specified in the `REAL_LD_FILE_NAME' configuration macro,
1851 * `ld' in the compiler's search directories, except that `collect2'
1852 will not execute itself recursively.
1856 "The compiler's search directories" means all the directories where
1857 `gcc' searches for passes of the compiler. This includes directories
1858 that you specify with `-B'.
1860 Cross-compilers search a little differently:
1862 * `real-ld' in the compiler's search directories.
1864 * `TARGET-real-ld' in `PATH'.
1866 * The file specified in the `REAL_LD_FILE_NAME' configuration macro,
1869 * `ld' in the compiler's search directories.
1871 * `TARGET-ld' in `PATH'.
1873 `collect2' explicitly avoids running `ld' using the file name under
1874 which `collect2' itself was invoked. In fact, it remembers up a list
1875 of such names--in case one copy of `collect2' finds another copy (or
1876 version) of `collect2' installed as `ld' in a second place in the
1879 `collect2' searches for the utilities `nm' and `strip' using the
1880 same algorithm as above for `ld'.
1882 Standard Header File Directories
1883 ================================
1885 `GCC_INCLUDE_DIR' means the same thing for native and cross. It is
1886 where GNU CC stores its private include files, and also where GNU CC
1887 stores the fixed include files. A cross compiled GNU CC runs
1888 `fixincludes' on the header files in `$(tooldir)/include'. (If the
1889 cross compilation header files need to be fixed, they must be installed
1890 before GNU CC is built. If the cross compilation header files are
1891 already suitable for ANSI C and GNU CC, nothing special need be done).
1893 `GPLUS_INCLUDE_DIR' means the same thing for native and cross. It
1894 is where `g++' looks first for header files. `libg++' installs only
1895 target independent header files in that directory.
1897 `LOCAL_INCLUDE_DIR' is used only for a native compiler. It is
1898 normally `/usr/local/include'. GNU CC searches this directory so that
1899 users can install header files in `/usr/local/include'.
1901 `CROSS_INCLUDE_DIR' is used only for a cross compiler. GNU CC
1902 doesn't install anything there.
1904 `TOOL_INCLUDE_DIR' is used for both native and cross compilers. It
1905 is the place for other packages to install header files that GNU CC will
1906 use. For a cross-compiler, this is the equivalent of `/usr/include'.
1907 When you build a cross-compiler, `fixincludes' processes any header
1908 files in this directory.