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.
71 You can specify a version number after any of the system types,
72 and some of the CPU types. In most cases, the version is
73 irrelevant, and will be ignored. So you might as well specify the
74 version if you know it.
76 See *Note Configurations::, for a list of supported configuration
77 names and notes on many of the configurations. You should check
78 the notes in that section before proceeding any further with the
79 installation of GNU CC.
81 There are four additional options you can specify independently to
82 describe variant hardware and software configurations. These are
83 `--with-gnu-as', `--with-gnu-ld', `--with-stabs' and `--nfp'.
86 If you will use GNU CC with the GNU assembler (GAS), you
87 should declare this by using the `--with-gnu-as' option when
90 Using this option does not install GAS. It only modifies the
91 output of GNU CC to work with GAS. Building and installing
94 Conversely, if you *do not* wish to use GAS and do not specify
95 `--with-gnu-as' when building GNU CC, it is up to you to make
96 sure that GAS is not installed. GNU CC searches for a
97 program named `as' in various directories; if the program it
98 finds is GAS, then it runs GAS. If you are not sure where
99 GNU CC finds the assembler it is using, try specifying `-v'
102 The systems where it makes a difference whether you use GAS
104 `hppa1.0-ANY-ANY', `hppa1.1-ANY-ANY', `i386-ANY-sysv',
106 `i860-ANY-bsd', `m68k-bull-sysv',
107 `m68k-hp-hpux', `m68k-sony-bsd',
108 `m68k-altos-sysv', `m68000-hp-hpux',
109 `m68000-att-sysv', `ANY-lynx-lynxos', and `mips-ANY'). On
110 any other system, `--with-gnu-as' has no effect.
112 On the systems listed above (except for the HP-PA, for ISC on
113 the 386, and for `mips-sgi-irix5.*'), if you use GAS, you
114 should also use the GNU linker (and specify `--with-gnu-ld').
117 Specify the option `--with-gnu-ld' if you plan to use the GNU
120 This option does not cause the GNU linker to be installed; it
121 just modifies the behavior of GNU CC to work with the GNU
122 linker. Specifically, it inhibits the installation of
123 `collect2', a program which otherwise serves as a front-end
124 for the system's linker on most configurations.
127 On MIPS based systems and on Alphas, you must specify whether
128 you want GNU CC to create the normal ECOFF debugging format,
129 or to use BSD-style stabs passed through the ECOFF symbol
130 table. The normal ECOFF debug format cannot fully handle
131 languages other than C. BSD stabs format can handle other
132 languages, but it only works with the GNU debugger GDB.
134 Normally, GNU CC uses the ECOFF debugging format by default;
135 if you prefer BSD stabs, specify `--with-stabs' when you
138 No matter which default you choose when you configure GNU CC,
139 the user can use the `-gcoff' and `-gstabs+' options to
140 specify explicitly the debug format for a particular
143 `--with-stabs' is meaningful on the ISC system on the 386,
144 also, if `--with-gas' is used. It selects use of stabs
145 debugging information embedded in COFF output. This kind of
146 debugging information supports C++ well; ordinary COFF
147 debugging information does not.
149 `--with-stabs' is also meaningful on 386 systems running
150 SVR4. It selects use of stabs debugging information embedded
151 in ELF output. The C++ compiler currently (2.6.0) does not
152 support the DWARF debugging information normally used on 386
153 SVR4 platforms; stabs provide a workable alternative. This
154 requires gas and gdb, as the normal SVR4 tools can not
155 generate or interpret stabs.
158 On certain systems, you must specify whether the machine has
159 a floating point unit. These systems include
160 `m68k-sun-sunosN' and `m68k-isi-bsd'. On any other system,
161 `--nfp' currently has no effect, though perhaps there are
162 other systems where it could usefully make a difference.
164 `--enable-objcthreads=TYPE'
165 Certain systems, notably Linux-based GNU systems, can't be
166 relied on to supply a threads facility for the Objective C
167 runtime and so will default to single-threaded runtime. They
168 may, however, have a library threads implementation
169 available, in which case threads can be enabled with this
170 option by supplying a suitable TYPE, probably `posix'. The
171 possibilities for TYPE are `single', `posix', `win32',
172 `solaris', `irix' and `mach'.
174 The `configure' script searches subdirectories of the source
175 directory for other compilers that are to be integrated into GNU
176 CC. The GNU compiler for C++, called G++ is in a subdirectory
177 named `cp'. `configure' inserts rules into `Makefile' to build
178 all of those compilers.
180 Here we spell out what files will be set up by `configure'.
181 Normally you need not be concerned with these files.
183 * A file named `config.h' is created that contains a `#include'
184 of the top-level config file for the machine you will run the
185 compiler on (*note The Configuration File:
186 (gcc.info)Config.). This file is responsible for defining
187 information about the host machine. It includes `tm.h'.
189 The top-level config file is located in the subdirectory
190 `config'. Its name is always `xm-SOMETHING.h'; usually
191 `xm-MACHINE.h', but there are some exceptions.
193 If your system does not support symbolic links, you might
194 want to set up `config.h' to contain a `#include' command
195 which refers to the appropriate file.
197 * A file named `tconfig.h' is created which includes the
198 top-level config file for your target machine. This is used
199 for compiling certain programs to run on that machine.
201 * A file named `tm.h' is created which includes the
202 machine-description macro file for your target machine. It
203 should be in the subdirectory `config' and its name is often
206 * The command file `configure' also constructs the file
207 `Makefile' by adding some text to the template file
208 `Makefile.in'. The additional text comes from files in the
209 `config' directory, named `t-TARGET' and `x-HOST'. If these
210 files do not exist, it means nothing needs to be added for a
211 given target or host.
213 4. The standard directory for installing GNU CC is `/usr/local/lib'.
214 If you want to install its files somewhere else, specify
215 `--prefix=DIR' when you run `configure'. Here DIR is a directory
216 name to use instead of `/usr/local' for all purposes with one
217 exception: the directory `/usr/local/include' is searched for
218 header files no matter where you install the compiler. To override
219 this name, use the `--local-prefix' option below.
221 5. Specify `--local-prefix=DIR' if you want the compiler to search
222 directory `DIR/include' for locally installed header files
223 *instead* of `/usr/local/include'.
225 You should specify `--local-prefix' *only* if your site has a
226 different convention (not `/usr/local') for where to put
229 The default value for `--local-prefix' is `/usr/local' regardless
230 of the value of `--prefix'. Specifying `--prefix' has no effect
231 on which directory GNU CC searches for local header files. This
232 may seem counterintuitive, but actually it is logical.
234 The purpose of `--prefix' is to specify where to *install GNU CC*.
235 The local header files in `/usr/local/include'--if you put any in
236 that directory--are not part of GNU CC. They are part of other
237 programs--perhaps many others. (GNU CC installs its own header
238 files in another directory which is based on the `--prefix' value.)
240 *Do not* specify `/usr' as the `--local-prefix'! The directory
241 you use for `--local-prefix' *must not* contain any of the
242 system's standard header files. If it did contain them, certain
243 programs would be miscompiled (including GNU Emacs, on certain
244 targets), because this would override and nullify the header file
245 corrections made by the `fixincludes' script.
247 Indications are that people who use this option use it based on
248 mistaken ideas of what it is for. People use it as if it specified
249 where to install part of GNU CC. Perhaps they make this assumption
250 because installing GNU CC creates the directory.
252 6. Make sure the Bison parser generator is installed. (This is
253 unnecessary if the Bison output files `c-parse.c' and `cexp.c' are
254 more recent than `c-parse.y' and `cexp.y' and you do not plan to
255 change the `.y' files.)
257 Bison versions older than Sept 8, 1988 will produce incorrect
258 output for `c-parse.c'.
260 7. If you have chosen a configuration for GNU CC which requires other
261 GNU tools (such as GAS or the GNU linker) instead of the standard
262 system tools, install the required tools in the build directory
263 under the names `as', `ld' or whatever is appropriate. This will
264 enable the compiler to find the proper tools for compilation of
265 the program `enquire'.
267 Alternatively, you can do subsequent compilation using a value of
268 the `PATH' environment variable such that the necessary GNU tools
269 come before the standard system tools.
271 8. Build the compiler. Just type `make LANGUAGES=c' in the compiler
274 `LANGUAGES=c' specifies that only the C compiler should be
275 compiled. The makefile normally builds compilers for all the
276 supported languages; currently, C, C++ and Objective C. However,
277 C is the only language that is sure to work when you build with
278 other non-GNU C compilers. In addition, building anything but C
279 at this stage is a waste of time.
281 In general, you can specify the languages to build by typing the
282 argument `LANGUAGES="LIST"', where LIST is one or more words from
283 the list `c', `c++', and `objective-c'. If you have any
284 additional GNU compilers as subdirectories of the GNU CC source
285 directory, you may also specify their names in this list.
287 Ignore any warnings you may see about "statement not reached" in
288 `insn-emit.c'; they are normal. Also, warnings about "unknown
289 escape sequence" are normal in `genopinit.c' and perhaps some
290 other files. Likewise, you should ignore warnings about "constant
291 is so large that it is unsigned" in `insn-emit.c' and
292 `insn-recog.c' and a warning about a comparison always being zero
293 in `enquire.o'. Any other compilation errors may represent bugs in
294 the port to your machine or operating system, and should be
295 investigated and reported.
297 Some commercial compilers fail to compile GNU CC because they have
298 bugs or limitations. For example, the Microsoft compiler is said
299 to run out of macro space. Some Ultrix compilers run out of
300 expression space; then you need to break up the statement where
303 9. If you are building a cross-compiler, stop here. *Note
306 10. Move the first-stage object files and executables into a
307 subdirectory with this command:
311 The files are moved into a subdirectory named `stage1'. Once
312 installation is complete, you may wish to delete these files with
315 11. If you have chosen a configuration for GNU CC which requires other
316 GNU tools (such as GAS or the GNU linker) instead of the standard
317 system tools, install the required tools in the `stage1'
318 subdirectory under the names `as', `ld' or whatever is
319 appropriate. This will enable the stage 1 compiler to find the
320 proper tools in the following stage.
322 Alternatively, you can do subsequent compilation using a value of
323 the `PATH' environment variable such that the necessary GNU tools
324 come before the standard system tools.
326 12. Recompile the compiler with itself, with this command:
328 make CC="stage1/xgcc -Bstage1/" CFLAGS="-g -O2"
330 This is called making the stage 2 compiler.
332 The command shown above builds compilers for all the supported
333 languages. If you don't want them all, you can specify the
334 languages to build by typing the argument `LANGUAGES="LIST"'. LIST
335 should contain one or more words from the list `c', `c++',
336 `objective-c', and `proto'. Separate the words with spaces.
337 `proto' stands for the programs `protoize' and `unprotoize'; they
338 are not a separate language, but you use `LANGUAGES' to enable or
339 disable their installation.
341 If you are going to build the stage 3 compiler, then you might
342 want to build only the C language in stage 2.
344 Once you have built the stage 2 compiler, if you are short of disk
345 space, you can delete the subdirectory `stage1'.
347 On a 68000 or 68020 system lacking floating point hardware, unless
348 you have selected a `tm.h' file that expects by default that there
349 is no such hardware, do this instead:
351 make CC="stage1/xgcc -Bstage1/" CFLAGS="-g -O2 -msoft-float"
353 13. If you wish to test the compiler by compiling it with itself one
354 more time, install any other necessary GNU tools (such as GAS or
355 the GNU linker) in the `stage2' subdirectory as you did in the
356 `stage1' subdirectory, then do this:
359 make CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O2"
361 This is called making the stage 3 compiler. Aside from the `-B'
362 option, the compiler options should be the same as when you made
363 the stage 2 compiler. But the `LANGUAGES' option need not be the
364 same. The command shown above builds compilers for all the
365 supported languages; if you don't want them all, you can specify
366 the languages to build by typing the argument `LANGUAGES="LIST"',
369 If you do not have to install any additional GNU tools, you may
372 make bootstrap LANGUAGES=LANGUAGE-LIST BOOT_CFLAGS=OPTION-LIST
374 instead of making `stage1', `stage2', and performing the two
377 14. Then compare the latest object files with the stage 2 object
378 files--they ought to be identical, aside from time stamps (if any).
380 On some systems, meaningful comparison of object files is
381 impossible; they always appear "different." This is currently
382 true on Solaris and some systems that use ELF object file format.
383 On some versions of Irix on SGI machines and DEC Unix (OSF/1) on
384 Alpha systems, you will not be able to compare the files without
385 specifying `-save-temps'; see the description of individual
386 systems above to see if you get comparison failures. You may have
387 similar problems on other systems.
389 Use this command to compare the files:
393 This will mention any object files that differ between stage 2 and
394 stage 3. Any difference, no matter how innocuous, indicates that
395 the stage 2 compiler has compiled GNU CC incorrectly, and is
396 therefore a potentially serious bug which you should investigate
399 If your system does not put time stamps in the object files, then
400 this is a faster way to compare them (using the Bourne shell):
403 cmp $file stage2/$file
406 If you have built the compiler with the `-mno-mips-tfile' option on
407 MIPS machines, you will not be able to compare the files.
409 15. Install the compiler driver, the compiler's passes and run-time
410 support with `make install'. Use the same value for `CC',
411 `CFLAGS' and `LANGUAGES' that you used when compiling the files
412 that are being installed. One reason this is necessary is that
413 some versions of Make have bugs and recompile files gratuitously
414 when you do this step. If you use the same variable values, those
415 files will be recompiled properly.
417 For example, if you have built the stage 2 compiler, you can use
418 the following command:
420 make install CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O" LANGUAGES="LIST"
422 This copies the files `cc1', `cpp' and `libgcc.a' to files `cc1',
423 `cpp' and `libgcc.a' in the directory
424 `/usr/local/lib/gcc-lib/TARGET/VERSION', which is where the
425 compiler driver program looks for them. Here TARGET is the target
426 machine type specified when you ran `configure', and VERSION is
427 the version number of GNU CC. This naming scheme permits various
428 versions and/or cross-compilers to coexist. It also copies the
429 executables for compilers for other languages (e.g., `cc1plus' for
430 C++) to the same directory.
432 This also copies the driver program `xgcc' into
433 `/usr/local/bin/gcc', so that it appears in typical execution
434 search paths. It also copies `gcc.1' into `/usr/local/man/man1'
435 and info pages into `/usr/local/info'.
437 On some systems, this command causes recompilation of some files.
438 This is usually due to bugs in `make'. You should either ignore
439 this problem, or use GNU Make.
441 *Warning: there is a bug in `alloca' in the Sun library. To avoid
442 this bug, be sure to install the executables of GNU CC that were
443 compiled by GNU CC. (That is, the executables from stage 2 or 3,
444 not stage 1.) They use `alloca' as a built-in function and never
445 the one in the library.*
447 (It is usually better to install GNU CC executables from stage 2
448 or 3, since they usually run faster than the ones compiled with
449 some other compiler.)
451 16. If you're going to use C++, it's likely that you need to also
452 install the libg++ distribution. It should be available from the
453 same place where you got the GNU C distribution. Just as GNU C
454 does not distribute a C runtime library, it also does not include
455 a C++ run-time library. All I/O functionality, special class
456 libraries, etc., are available in the libg++ distribution.
458 17. GNU CC includes a runtime library for Objective-C because it is an
459 integral part of the language. You can find the files associated
460 with the library in the subdirectory `objc'. The GNU Objective-C
461 Runtime Library requires header files for the target's C library in
462 order to be compiled,and also requires the header files for the
463 target's thread library if you want thread support. *Note
464 Cross-Compilers and Header Files: Cross Headers, for discussion
465 about header files issues for cross-compilation.
467 When you run `configure', it picks the appropriate Objective-C
468 thread implementation file for the target platform. In some
469 situations, you may wish to choose a different back-end as some
470 platforms support multiple thread implementations or you may wish
471 to disable thread support completely. You do this by specifying a
472 value for the OBJC_THREAD_FILE makefile variable on the command
473 line when you run make, for example:
475 make CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O2" OBJC_THREAD_FILE=thr-single
477 Below is a list of the currently available back-ends.
479 * thr-single Disable thread support, should work for all
482 * thr-decosf1 DEC OSF/1 thread support.
484 * thr-irix SGI IRIX thread support.
486 * thr-mach Generic MACH thread support, known to work on
489 * thr-os2 IBM OS/2 thread support.
491 * thr-posix Generix POSIX thread support.
493 * thr-pthreads PCThreads on Linux-based GNU systems.
495 * thr-solaris SUN Solaris thread support.
497 * thr-win32 Microsoft Win32 API thread support.
499 Configurations Supported by GNU CC
500 ==================================
502 Here are the possible CPU types:
504 1750a, a29k, alpha, arm, cN, clipper, dsp16xx, elxsi, h8300,
505 hppa1.0, hppa1.1, i370, i386, i486, i586, i860, i960, m32r,
506 m68000, m68k, m88k, mips, mipsel, mips64, mips64el, ns32k,
507 powerpc, powerpcle, pyramid, romp, rs6000, sh, sparc, sparclite,
510 Here are the recognized company names. As you can see, customary
511 abbreviations are used rather than the longer official names.
513 acorn, alliant, altos, apollo, apple, att, bull, cbm, convergent,
514 convex, crds, dec, dg, dolphin, elxsi, encore, harris, hitachi,
515 hp, ibm, intergraph, isi, mips, motorola, ncr, next, ns, omron,
516 plexus, sequent, sgi, sony, sun, tti, unicom, wrs.
518 The company name is meaningful only to disambiguate when the rest of
519 the information supplied is insufficient. You can omit it, writing
520 just `CPU-SYSTEM', if it is not needed. For example, `vax-ultrix4.2'
521 is equivalent to `vax-dec-ultrix4.2'.
523 Here is a list of system types:
525 386bsd, aix, acis, amigaos, aos, aout, aux, bosx, bsd, clix, coff,
526 ctix, cxux, dgux, dynix, ebmon, ecoff, elf, esix, freebsd, hms,
527 genix, gnu, linux-gnu, hiux, hpux, iris, irix, isc, luna, lynxos,
528 mach, minix, msdos, mvs, netbsd, newsos, nindy, ns, osf, osfrose,
529 ptx, riscix, riscos, rtu, sco, sim, solaris, sunos, sym, sysv,
530 udi, ultrix, unicos, uniplus, unos, vms, vsta, vxworks, winnt,
533 You can omit the system type; then `configure' guesses the operating
534 system from the CPU and company.
536 You can add a version number to the system type; this may or may not
537 make a difference. For example, you can write `bsd4.3' or `bsd4.4' to
538 distinguish versions of BSD. In practice, the version number is most
539 needed for `sysv3' and `sysv4', which are often treated differently.
541 If you specify an impossible combination such as `i860-dg-vms', then
542 you may get an error message from `configure', or it may ignore part of
543 the information and do the best it can with the rest. `configure'
544 always prints the canonical name for the alternative that it used. GNU
545 CC does not support all possible alternatives.
547 Often a particular model of machine has a name. Many machine names
548 are recognized as aliases for CPU/company combinations. Thus, the
549 machine name `sun3', mentioned above, is an alias for `m68k-sun'.
550 Sometimes we accept a company name as a machine name, when the name is
551 popularly used for a particular machine. Here is a table of the known
554 3300, 3b1, 3bN, 7300, altos3068, altos, apollo68, att-7300,
555 balance, convex-cN, crds, decstation-3100, decstation, delta,
556 encore, fx2800, gmicro, hp7NN, hp8NN, hp9k2NN, hp9k3NN, hp9k7NN,
557 hp9k8NN, iris4d, iris, isi68, m3230, magnum, merlin, miniframe,
558 mmax, news-3600, news800, news, next, pbd, pc532, pmax, powerpc,
559 powerpcle, ps2, risc-news, rtpc, sun2, sun386i, sun386, sun3,
560 sun4, symmetry, tower-32, tower.
562 Remember that a machine name specifies both the cpu type and the company
563 name. If you want to install your own homemade configuration files,
564 you can use `local' as the company name to access them. If you use
565 configuration `CPU-local', the configuration name without the cpu prefix
566 is used to form the configuration file names.
568 Thus, if you specify `m68k-local', configuration uses files
569 `m68k.md', `local.h', `m68k.c', `xm-local.h', `t-local', and `x-local',
570 all in the directory `config/m68k'.
572 Here is a list of configurations that have special treatment or
573 special things you must know:
576 MIL-STD-1750A processors.
578 The MIL-STD-1750A cross configuration produces output for
579 `as1750', an assembler/linker available under the GNU Public
580 License for the 1750A. `as1750' can be obtained at
581 *ftp://ftp.fta-berlin.de/pub/crossgcc/1750gals/*. A similarly
582 licensed simulator for the 1750A is available from same address.
584 You should ignore a fatal error during the building of libgcc
585 (libgcc is not yet implemented for the 1750A.)
587 The `as1750' assembler requires the file `ms1750.inc', which is
588 found in the directory `config/1750a'.
590 GNU CC produced the same sections as the Fairchild F9450 C
594 The program code section.
597 The read/write (RAM) data section.
600 The read-only (ROM) constants section.
603 Initialization section (code to copy KREL to SREL).
605 The smallest addressable unit is 16 bits (BITS_PER_UNIT is 16).
606 This means that type `char' is represented with a 16-bit word per
607 character. The 1750A's "Load/Store Upper/Lower Byte" instructions
608 are not used by GNU CC.
611 Systems using processors that implement the DEC Alpha architecture
612 and are running the DEC Unix (OSF/1) operating system, for example
613 the DEC Alpha AXP systems. (VMS on the Alpha is not currently
614 supported by GNU CC.)
616 GNU CC writes a `.verstamp' directive to the assembler output file
617 unless it is built as a cross-compiler. It gets the version to
618 use from the system header file `/usr/include/stamp.h'. If you
619 install a new version of DEC Unix, you should rebuild GCC to pick
620 up the new version stamp.
622 Note that since the Alpha is a 64-bit architecture,
623 cross-compilers from 32-bit machines will not generate code as
624 efficient as that generated when the compiler is running on a
625 64-bit machine because many optimizations that depend on being
626 able to represent a word on the target in an integral value on the
627 host cannot be performed. Building cross-compilers on the Alpha
628 for 32-bit machines has only been tested in a few cases and may
631 `make compare' may fail on old versions of DEC Unix unless you add
632 `-save-temps' to `CFLAGS'. On these systems, the name of the
633 assembler input file is stored in the object file, and that makes
634 comparison fail if it differs between the `stage1' and `stage2'
635 compilations. The option `-save-temps' forces a fixed name to be
636 used for the assembler input file, instead of a randomly chosen
637 name in `/tmp'. Do not add `-save-temps' unless the comparisons
638 fail without that option. If you add `-save-temps', you will have
639 to manually delete the `.i' and `.s' files after each series of
642 GNU CC now supports both the native (ECOFF) debugging format used
643 by DBX and GDB and an encapsulated STABS format for use only with
644 GDB. See the discussion of the `--with-stabs' option of
645 `configure' above for more information on these formats and how to
648 There is a bug in DEC's assembler that produces incorrect line
649 numbers for ECOFF format when the `.align' directive is used. To
650 work around this problem, GNU CC will not emit such alignment
651 directives while writing ECOFF format debugging information even
652 if optimization is being performed. Unfortunately, this has the
653 very undesirable side-effect that code addresses when `-O' is
654 specified are different depending on whether or not `-g' is also
657 To avoid this behavior, specify `-gstabs+' and use GDB instead of
658 DBX. DEC is now aware of this problem with the assembler and
659 hopes to provide a fix shortly.
662 Argonaut ARC processor. This configuration is intended for
666 Advanced RISC Machines ARM-family processors. These are often
667 used in embedded applications. There are no standard Unix
668 configurations. This configuration corresponds to the basic
669 instruction sequences and will produce `a.out' format object
672 You may need to make a variant of the file `arm.h' for your
673 particular configuration.
676 Any of the ARM family processors running the Linux-based GNU
677 system with the `a.out' binary format (ELF is not yet supported).
678 You must use version 2.8.1.0.7 or later of the Linux binutils,
679 which you can download from `sunsite.unc.edu:/pub/Linux/GCC' and
680 other mirror sites for Linux-based GNU systems.
683 The ARM2 or ARM3 processor running RISC iX, Acorn's port of BSD
684 Unix. If you are running a version of RISC iX prior to 1.2 then
685 you must specify the version number during configuration. Note
686 that the assembler shipped with RISC iX does not support stabs
687 debugging information; a new version of the assembler, with stabs
688 support included, is now available from Acorn.
691 AMD Am29k-family processors. These are normally used in embedded
692 applications. There are no standard Unix configurations. This
693 configuration corresponds to AMD's standard calling sequence and
694 binary interface and is compatible with other 29k tools.
696 You may need to make a variant of the file `a29k.h' for your
697 particular configuration.
700 AMD Am29050 used in a system running a variant of BSD Unix.
703 DECstations can support three different personalities: Ultrix, DEC
704 OSF/1, and OSF/rose. To configure GCC for these platforms use the
705 following configurations:
708 Ultrix configuration.
711 Dec's version of OSF/1.
714 Open Software Foundation reference port of OSF/1 which uses
715 the OSF/rose object file format instead of ECOFF. Normally,
716 you would not select this configuration.
718 The MIPS C compiler needs to be told to increase its table size
719 for switch statements with the `-Wf,-XNg1500' option in order to
720 compile `cp/parse.c'. If you use the `-O2' optimization option,
721 you also need to use `-Olimit 3000'. Both of these options are
722 automatically generated in the `Makefile' that the shell script
723 `configure' builds. If you override the `CC' make variable and
724 use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
728 The Elxsi's C compiler has known limitations that prevent it from
729 compiling GNU C. Please contact `mrs@cygnus.com' for more details.
732 A port to the AT&T DSP1610 family of processors.
735 Hitachi H8/300 series of processors.
737 The calling convention and structure layout has changed in release
738 2.6. All code must be recompiled. The calling convention now
739 passes the first three arguments in function calls in registers.
740 Structures are no longer a multiple of 2 bytes.
743 There are several variants of the HP-PA processor which run a
744 variety of operating systems. GNU CC must be configured to use
745 the correct processor type and operating system, or GNU CC will
746 not function correctly. The easiest way to handle this problem is
747 to *not* specify a target when configuring GNU CC, the `configure'
748 script will try to automatically determine the right processor
749 type and operating system.
751 `-g' does not work on HP-UX, since that system uses a peculiar
752 debugging format which GNU CC does not know about. However, `-g'
753 will work if you also use GAS and GDB in conjunction with GCC. We
754 highly recommend using GAS for all HP-PA configurations.
756 You should be using GAS-2.6 (or later) along with GDB-4.16 (or
757 later). These can be retrieved from all the traditional GNU ftp
760 GAS will need to be installed into a directory before `/bin',
761 `/usr/bin', and `/usr/ccs/bin' in your search path. You should
762 install GAS before you build GNU CC.
764 To enable debugging, you must configure GNU CC with the
765 `--with-gnu-as' option before building.
768 This port is very preliminary and has many known bugs. We hope to
769 have a higher-quality port for this machine soon.
771 `i386-*-linux-gnuoldld'
772 Use this configuration to generate `a.out' binaries on Linux-based
773 GNU systems if you do not have gas/binutils version 2.5.2 or later
774 installed. This is an obsolete configuration.
776 `i386-*-linux-gnuaout'
777 Use this configuration to generate `a.out' binaries on Linux-based
778 GNU systems. This configuration is being superseded. You must use
779 gas/binutils version 2.5.2 or later.
782 Use this configuration to generate ELF binaries on Linux-based GNU
783 systems. You must use gas/binutils version 2.5.2 or later.
786 Compilation with RCC is recommended. Also, it may be a good idea
787 to link with GNU malloc instead of the malloc that comes with the
791 Use this configuration for SCO release 3.2 version 4.
794 Use this for the SCO OpenServer Release family including 5.0.0,
795 5.0.2, 5.0.4, Internet FastStart 1.0, and Internet FastStart 1.1.
797 GNU CC can generate ELF binaries (if you specify `-melf') or COFF
798 binaries (the default). If you are going to build your compiler
799 in ELF mode (once you have bootstrapped the first stage compiler)
800 you *must* specify `-melf' as part of `CC', *not* `CFLAGS', for
801 example as `CC="stage1/xgcc -melf -Bstage1/" '. If you do not do
802 this, the bootstrap will generate incorrect versions of `libgcc.a'.
804 You must have TLS597 (from ftp.sco.com/TLS) installed for ELF
805 binaries to work correctly. Note that Open Server 5.0.2 *does*
806 need TLS597 installed.
808 *NOTE:* You must follow the instructions about invoking `make
809 bootstrap' because the native OpenServer compiler builds a
810 `cc1plus' that will not correctly parse many valid C++ programs.
811 You must do a `make bootstrap' if you are building with the native
815 It may be a good idea to link with GNU malloc instead of the
816 malloc that comes with the system.
818 In ISC version 4.1, `sed' core dumps when building `deduced.h'.
819 Use the version of `sed' from version 4.0.
822 It may be good idea to link with GNU malloc instead of the malloc
823 that comes with the system.
826 You need to use GAS version 2.1 or later, and LD from GNU binutils
827 version 2.2 or later.
830 Go to the Berkeley universe before compiling. In addition, you
831 probably need to create a file named `string.h' containing just
832 one line: `#include <strings.h>'.
835 Sequent DYNIX/ptx 1.x.
838 Sequent DYNIX/ptx 2.x.
841 You may find that you need another version of GNU CC to begin
842 bootstrapping with, since the current version when built with the
843 system's own compiler seems to get an infinite loop compiling part
844 of `libgcc2.c'. GNU CC version 2 compiled with GNU CC (any
845 version) seems not to have this problem.
847 See *Note Sun Install::, for information on installing GNU CC on
850 `i[345]86-*-winnt3.5'
851 This version requires a GAS that has not yet been released. Until
852 it is, you can get a prebuilt binary version via anonymous ftp from
853 `cs.washington.edu:pub/gnat' or `cs.nyu.edu:pub/gnat'. You must
854 also use the Microsoft header files from the Windows NT 3.5 SDK.
855 Find these on the CDROM in the `/mstools/h' directory dated
856 9/4/94. You must use a fixed version of Microsoft linker made
857 especially for NT 3.5, which is also is available on the NT 3.5
858 SDK CDROM. If you do not have this linker, can you also use the
859 linker from Visual C/C++ 1.0 or 2.0.
861 Installing GNU CC for NT builds a wrapper linker, called `ld.exe',
862 which mimics the behaviour of Unix `ld' in the specification of
863 libraries (`-L' and `-l'). `ld.exe' looks for both Unix and
864 Microsoft named libraries. For example, if you specify `-lfoo',
865 `ld.exe' will look first for `libfoo.a' and then for `foo.lib'.
867 You may install GNU CC for Windows NT in one of two ways,
868 depending on whether or not you have a Unix-like shell and various
871 1. If you do not have a Unix-like shell and few Unix-like
872 utilities, you will use a DOS style batch script called
873 `configure.bat'. Invoke it as `configure winnt' from an
874 MSDOS console window or from the program manager dialog box.
875 `configure.bat' assumes you have already installed and have
876 in your path a Unix-like `sed' program which is used to
877 create a working `Makefile' from `Makefile.in'.
879 `Makefile' uses the Microsoft Nmake program maintenance
880 utility and the Visual C/C++ V8.00 compiler to build GNU CC.
881 You need only have the utilities `sed' and `touch' to use
882 this installation method, which only automatically builds the
883 compiler itself. You must then examine what `fixinc.winnt'
884 does, edit the header files by hand and build `libgcc.a'
887 2. The second type of installation assumes you are running a
888 Unix-like shell, have a complete suite of Unix-like utilities
889 in your path, and have a previous version of GNU CC already
890 installed, either through building it via the above
891 installation method or acquiring a pre-built binary. In this
892 case, use the `configure' script in the normal fashion.
895 This is the Paragon. If you have version 1.0 of the operating
896 system, you need to take special steps to build GNU CC due to
897 peculiarities of the system. Newer system versions have no
898 problem. See the section `Installation Problems' in the GNU CC
902 LynxOS 2.2 and earlier comes with GNU CC 1.x already installed as
903 `/bin/gcc'. You should compile with this instead of `/bin/cc'.
904 You can tell GNU CC to use the GNU assembler and linker, by
905 specifying `--with-gnu-as --with-gnu-ld' when configuring. These
906 will produce COFF format object files and executables; otherwise
907 GNU CC will use the installed tools, which produce `a.out' format
911 Mitsubishi M32R processor. This configuration is intended for
915 HP 9000 series 200 running BSD. Note that the C compiler that
916 comes with this system cannot compile GNU CC; contact
917 `law@cs.utah.edu' to get binaries of GNU CC for bootstrapping.
920 Altos 3068. You must use the GNU assembler, linker and debugger.
921 Also, you must fix a kernel bug. Details in the file
925 Apple Macintosh running A/UX. You may configure GCC to use
926 either the system assembler and linker or the GNU assembler and
927 linker. You should use the GNU configuration if you can,
928 especially if you also want to use GNU C++. You enabled that
929 configuration with + the `--with-gnu-as' and `--with-gnu-ld'
930 options to `configure'.
932 Note the C compiler that comes with this system cannot compile GNU
933 CC. You can fine binaries of GNU CC for bootstrapping on
934 `jagubox.gsfc.nasa.gov'. You will also a patched version of
935 `/bin/ld' there that raises some of the arbitrary limits found in
939 AT&T 3b1, a.k.a. 7300 PC. Special procedures are needed to
940 compile GNU CC with this machine's standard C compiler, due to
941 bugs in that compiler. You can bootstrap it more easily with
942 previous versions of GNU CC if you have them.
944 Installing GNU CC on the 3b1 is difficult if you do not already
945 have GNU CC running, due to bugs in the installed C compiler.
946 However, the following procedure might work. We are unable to
949 1. Comment out the `#include "config.h"' line near the start of
950 `cccp.c' and do `make cpp'. This makes a preliminary version
953 2. Save the old `/lib/cpp' and copy the preliminary GNU cpp to
956 3. Undo your change in `cccp.c', or reinstall the original
957 version, and do `make cpp' again.
959 4. Copy this final version of GNU cpp into `/lib/cpp'.
961 5. Replace every occurrence of `obstack_free' in the file
962 `tree.c' with `_obstack_free'.
964 6. Run `make' to get the first-stage GNU CC.
966 7. Reinstall the original version of `/lib/cpp'.
968 8. Now you can compile GNU CC with itself and install it in the
972 Bull DPX/2 series 200 and 300 with BOS-2.00.45 up to BOS-2.01. GNU
973 CC works either with native assembler or GNU assembler. You can use
974 GNU assembler with native coff generation by providing
975 `--with-gnu-as' to the configure script or use GNU assembler with
976 dbx-in-coff encapsulation by providing `--with-gnu-as --stabs'.
977 For any problem with native assembler or for availability of the
978 DPX/2 port of GAS, contact `F.Pierresteguy@frcl.bull.fr'.
981 Use `configure unos' for building on Unos.
983 The Unos assembler is named `casm' instead of `as'. For some
984 strange reason linking `/bin/as' to `/bin/casm' changes the
985 behavior, and does not work. So, when installing GNU CC, you
986 should install the following script as `as' in the subdirectory
987 where the passes of GCC are installed:
992 The default Unos library is named `libunos.a' instead of `libc.a'.
993 To allow GNU CC to function, either change all references to
994 `-lc' in `gcc.c' to `-lunos' or link `/lib/libc.a' to
997 When compiling GNU CC with the standard compiler, to overcome bugs
998 in the support of `alloca', do not use `-O' when making stage 2.
999 Then use the stage 2 compiler with `-O' to make the stage 3
1000 compiler. This compiler will have the same characteristics as the
1001 usual stage 2 compiler on other systems. Use it to make a stage 4
1002 compiler and compare that with stage 3 to verify proper
1005 (Perhaps simply defining `ALLOCA' in `x-crds' as described in the
1006 comments there will make the above paragraph superfluous. Please
1007 inform us of whether this works.)
1009 Unos uses memory segmentation instead of demand paging, so you
1010 will need a lot of memory. 5 Mb is barely enough if no other
1011 tasks are running. If linking `cc1' fails, try putting the object
1012 files into a library and linking from that library.
1015 HP 9000 series 300 or 400 running HP-UX. HP-UX version 8.0 has a
1016 bug in the assembler that prevents compilation of GNU CC. To fix
1017 it, get patch PHCO_4484 from HP.
1019 In addition, if you wish to use gas `--with-gnu-as' you must use
1020 gas version 2.1 or later, and you must use the GNU linker version
1021 2.1 or later. Earlier versions of gas relied upon a program which
1022 converted the gas output into the native HP/UX format, but that
1023 program has not been kept up to date. gdb does not understand
1024 that native HP/UX format, so you must use gas if you wish to use
1028 Sun 3. We do not provide a configuration file to use the Sun FPA
1029 by default, because programs that establish signal handlers for
1030 floating point traps inherently cannot work with the FPA.
1032 See *Note Sun Install::, for information on installing GNU CC on
1036 Motorola m88k running the AT&T/Unisoft/Motorola V.3 reference port.
1037 These systems tend to use the Green Hills C, revision 1.8.5, as the
1038 standard C compiler. There are apparently bugs in this compiler
1039 that result in object files differences between stage 2 and stage
1040 3. If this happens, make the stage 4 compiler and compare it to
1041 the stage 3 compiler. If the stage 3 and stage 4 object files are
1042 identical, this suggests you encountered a problem with the
1043 standard C compiler; the stage 3 and 4 compilers may be usable.
1045 It is best, however, to use an older version of GNU CC for
1046 bootstrapping if you have one.
1049 Motorola m88k running DG/UX. To build 88open BCS native or cross
1050 compilers on DG/UX, specify the configuration name as
1051 `m88k-*-dguxbcs' and build in the 88open BCS software development
1052 environment. To build ELF native or cross compilers on DG/UX,
1053 specify `m88k-*-dgux' and build in the DG/UX ELF development
1054 environment. You set the software development environment by
1055 issuing `sde-target' command and specifying either `m88kbcs' or
1056 `m88kdguxelf' as the operand.
1058 If you do not specify a configuration name, `configure' guesses the
1059 configuration based on the current software development
1062 `m88k-tektronix-sysv3'
1063 Tektronix XD88 running UTekV 3.2e. Do not turn on optimization
1064 while building stage1 if you bootstrap with the buggy Green Hills
1065 compiler. Also, The bundled LAI System V NFS is buggy so if you
1066 build in an NFS mounted directory, start from a fresh reboot, or
1067 avoid NFS all together. Otherwise you may have trouble getting
1068 clean comparisons between stages.
1071 MIPS machines running the MIPS operating system in BSD mode. It's
1072 possible that some old versions of the system lack the functions
1073 `memcpy', `memcmp', and `memset'. If your system lacks these, you
1074 must remove or undo the definition of `TARGET_MEM_FUNCTIONS' in
1077 The MIPS C compiler needs to be told to increase its table size
1078 for switch statements with the `-Wf,-XNg1500' option in order to
1079 compile `cp/parse.c'. If you use the `-O2' optimization option,
1080 you also need to use `-Olimit 3000'. Both of these options are
1081 automatically generated in the `Makefile' that the shell script
1082 `configure' builds. If you override the `CC' make variable and
1083 use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
1087 The MIPS C compiler needs to be told to increase its table size
1088 for switch statements with the `-Wf,-XNg1500' option in order to
1089 compile `cp/parse.c'. If you use the `-O2' optimization option,
1090 you also need to use `-Olimit 3000'. Both of these options are
1091 automatically generated in the `Makefile' that the shell script
1092 `configure' builds. If you override the `CC' make variable and
1093 use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
1096 MIPS computers running RISC-OS can support four different
1097 personalities: default, BSD 4.3, System V.3, and System V.4 (older
1098 versions of RISC-OS don't support V.4). To configure GCC for
1099 these platforms use the following configurations:
1101 `mips-mips-riscos`rev''
1102 Default configuration for RISC-OS, revision `rev'.
1104 `mips-mips-riscos`rev'bsd'
1105 BSD 4.3 configuration for RISC-OS, revision `rev'.
1107 `mips-mips-riscos`rev'sysv4'
1108 System V.4 configuration for RISC-OS, revision `rev'.
1110 `mips-mips-riscos`rev'sysv'
1111 System V.3 configuration for RISC-OS, revision `rev'.
1113 The revision `rev' mentioned above is the revision of RISC-OS to
1114 use. You must reconfigure GCC when going from a RISC-OS revision
1115 4 to RISC-OS revision 5. This has the effect of avoiding a linker
1119 In order to compile GCC on an SGI running IRIX 4, the "c.hdr.lib"
1120 option must be installed from the CD-ROM supplied from Silicon
1121 Graphics. This is found on the 2nd CD in release 4.0.1.
1123 In order to compile GCC on an SGI running IRIX 5, the
1124 "compiler_dev.hdr" subsystem must be installed from the IDO CD-ROM
1125 supplied by Silicon Graphics.
1127 `make compare' may fail on version 5 of IRIX unless you add
1128 `-save-temps' to `CFLAGS'. On these systems, the name of the
1129 assembler input file is stored in the object file, and that makes
1130 comparison fail if it differs between the `stage1' and `stage2'
1131 compilations. The option `-save-temps' forces a fixed name to be
1132 used for the assembler input file, instead of a randomly chosen
1133 name in `/tmp'. Do not add `-save-temps' unless the comparisons
1134 fail without that option. If you do you `-save-temps', you will
1135 have to manually delete the `.i' and `.s' files after each series
1138 The MIPS C compiler needs to be told to increase its table size
1139 for switch statements with the `-Wf,-XNg1500' option in order to
1140 compile `cp/parse.c'. If you use the `-O2' optimization option,
1141 you also need to use `-Olimit 3000'. Both of these options are
1142 automatically generated in the `Makefile' that the shell script
1143 `configure' builds. If you override the `CC' make variable and
1144 use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
1147 On Irix version 4.0.5F, and perhaps on some other versions as well,
1148 there is an assembler bug that reorders instructions incorrectly.
1149 To work around it, specify the target configuration
1150 `mips-sgi-irix4loser'. This configuration inhibits assembler
1153 In a compiler configured with target `mips-sgi-irix4', you can turn
1154 off assembler optimization by using the `-noasmopt' option. This
1155 compiler option passes the option `-O0' to the assembler, to
1158 The `-noasmopt' option can be useful for testing whether a problem
1159 is due to erroneous assembler reordering. Even if a problem does
1160 not go away with `-noasmopt', it may still be due to assembler
1161 reordering--perhaps GNU CC itself was miscompiled as a result.
1163 To enable debugging under Irix 5, you must use GNU as 2.5 or later,
1164 and use the `--with-gnu-as' configure option when configuring gcc.
1165 GNU as is distributed as part of the binutils package.
1168 Sony MIPS NEWS. This works in NEWSOS 5.0.1, but not in 5.0.2
1169 (which uses ELF instead of COFF). Support for 5.0.2 will probably
1170 be provided soon by volunteers. In particular, the linker does
1171 not like the code generated by GCC when shared libraries are
1175 Encore ns32000 system. Encore systems are supported only under
1179 National Semiconductor ns32000 system. Genix has bugs in `alloca'
1180 and `malloc'; you must get the compiled versions of these from GNU
1184 Go to the Berkeley universe before compiling. In addition, you
1185 probably need to create a file named `string.h' containing just
1186 one line: `#include <strings.h>'.
1189 UTEK ns32000 system ("merlin"). The C compiler that comes with
1190 this system cannot compile GNU CC; contact `tektronix!reed!mason'
1191 to get binaries of GNU CC for bootstrapping.
1195 The only operating systems supported for the IBM RT PC are AOS and
1196 MACH. GNU CC does not support AIX running on the RT. We
1197 recommend you compile GNU CC with an earlier version of itself; if
1198 you compile GNU CC with `hc', the Metaware compiler, it will work,
1199 but you will get mismatches between the stage 2 and stage 3
1200 compilers in various files. These errors are minor differences in
1201 some floating-point constants and can be safely ignored; the stage
1202 3 compiler is correct.
1206 Various early versions of each release of the IBM XLC compiler
1207 will not bootstrap GNU CC. Symptoms include differences between
1208 the stage2 and stage3 object files, and errors when compiling
1209 `libgcc.a' or `enquire'. Known problematic releases include:
1210 xlc-1.2.1.8, xlc-1.3.0.0 (distributed with AIX 3.2.5), and
1211 xlc-1.3.0.19. Both xlc-1.2.1.28 and xlc-1.3.0.24 (PTF 432238) are
1212 known to produce working versions of GNU CC, but most other recent
1213 releases correctly bootstrap GNU CC. Also, releases of AIX prior
1214 to AIX 3.2.4 include a version of the IBM assembler which does not
1215 accept debugging directives: assembler updates are available as
1216 PTFs. Also, if you are using AIX 3.2.5 or greater and the GNU
1217 assembler, you must have a version modified after October 16th,
1218 1995 in order for the GNU C compiler to build. See the file
1219 `README.RS6000' for more details on of these problems.
1221 GNU CC does not yet support the 64-bit PowerPC instructions.
1223 Objective C does not work on this architecture because it makes
1224 assumptions that are incompatible with the calling conventions.
1226 AIX on the RS/6000 provides support (NLS) for environments outside
1227 of the United States. Compilers and assemblers use NLS to support
1228 locale-specific representations of various objects including
1229 floating-point numbers ("." vs "," for separating decimal
1230 fractions). There have been problems reported where the library
1231 linked with GNU CC does not produce the same floating-point
1232 formats that the assembler accepts. If you have this problem, set
1233 the LANG environment variable to "C" or "En_US".
1235 Due to changes in the way that GNU CC invokes the binder (linker)
1236 for AIX 4.1, you may now receive warnings of duplicate symbols
1237 from the link step that were not reported before. The assembly
1238 files generated by GNU CC for AIX have always included multiple
1239 symbol definitions for certain global variable and function
1240 declarations in the original program. The warnings should not
1241 prevent the linker from producing a correct library or runnable
1244 By default, AIX 4.1 produces code that can be used on either Power
1245 or PowerPC processors.
1247 You can specify a default version for the `-mcpu='CPU_TYPE switch
1248 by using the configure option `--with-cpu-'CPU_TYPE.
1252 PowerPC system in big endian mode, running System V.4.
1254 You can specify a default version for the `-mcpu='CPU_TYPE switch
1255 by using the configure option `--with-cpu-'CPU_TYPE.
1257 `powerpc-*-linux-gnu'
1258 PowerPC system in big endian mode, running the Linux-based GNU
1261 You can specify a default version for the `-mcpu='CPU_TYPE switch
1262 by using the configure option `--with-cpu-'CPU_TYPE.
1265 Embedded PowerPC system in big endian mode with -mcall-aix
1266 selected as the default.
1268 You can specify a default version for the `-mcpu='CPU_TYPE switch
1269 by using the configure option `--with-cpu-'CPU_TYPE.
1272 Embedded PowerPC system in big endian mode for use in running
1273 under the PSIM simulator.
1275 You can specify a default version for the `-mcpu='CPU_TYPE switch
1276 by using the configure option `--with-cpu-'CPU_TYPE.
1279 Embedded PowerPC system in big endian mode.
1281 You can specify a default version for the `-mcpu='CPU_TYPE switch
1282 by using the configure option `--with-cpu-'CPU_TYPE.
1286 PowerPC system in little endian mode, running System V.4.
1288 You can specify a default version for the `-mcpu='CPU_TYPE switch
1289 by using the configure option `--with-cpu-'CPU_TYPE.
1291 `powerpcle-*-solaris2*'
1292 PowerPC system in little endian mode, running Solaris 2.5.1 or
1295 You can specify a default version for the `-mcpu='CPU_TYPE switch
1296 by using the configure option `--with-cpu-'CPU_TYPE. Beta
1297 versions of the Sun 4.0 compiler do not seem to be able to build
1298 GNU CC correctly. There are also problems with the host assembler
1299 and linker that are fixed by using the GNU versions of these tools.
1301 `powerpcle-*-eabisim'
1302 Embedded PowerPC system in little endian mode for use in running
1303 under the PSIM simulator.
1306 Embedded PowerPC system in little endian mode.
1308 You can specify a default version for the `-mcpu='CPU_TYPE switch
1309 by using the configure option `--with-cpu-'CPU_TYPE.
1313 PowerPC system in little endian mode running Windows NT.
1315 You can specify a default version for the `-mcpu='CPU_TYPE switch
1316 by using the configure option `--with-cpu-'CPU_TYPE.
1319 Don't try compiling with Vax C (`vcc'). It produces incorrect code
1320 in some cases (for example, when `alloca' is used).
1322 Meanwhile, compiling `cp/parse.c' with pcc does not work because of
1323 an internal table size limitation in that compiler. To avoid this
1324 problem, compile just the GNU C compiler first, and use it to
1325 recompile building all the languages that you want to run.
1328 See *Note Sun Install::, for information on installing GNU CC on
1332 See *Note VMS Install::, for details on how to install GNU CC on
1336 These computers are also known as the 3b2, 3b5, 3b20 and other
1337 similar names. (However, the 3b1 is actually a 68000; see *Note
1340 Don't use `-g' when compiling with the system's compiler. The
1341 system's linker seems to be unable to handle such a large program
1342 with debugging information.
1344 The system's compiler runs out of capacity when compiling `stmt.c'
1345 in GNU CC. You can work around this by building `cpp' in GNU CC
1346 first, then use that instead of the system's preprocessor with the
1347 system's C compiler to compile `stmt.c'. Here is how:
1349 mv /lib/cpp /lib/cpp.att
1351 echo '/lib/cpp.gnu -traditional ${1+"$@"}' > /lib/cpp
1354 The system's compiler produces bad code for some of the GNU CC
1355 optimization files. So you must build the stage 2 compiler without
1356 optimization. Then build a stage 3 compiler with optimization.
1357 That executable should work. Here are the necessary commands:
1359 make LANGUAGES=c CC=stage1/xgcc CFLAGS="-Bstage1/ -g"
1361 make CC=stage2/xgcc CFLAGS="-Bstage2/ -g -O"
1363 You may need to raise the ULIMIT setting to build a C++ compiler,
1364 as the file `cc1plus' is larger than one megabyte.
1366 Compilation in a Separate Directory
1367 ===================================
1369 If you wish to build the object files and executables in a directory
1370 other than the one containing the source files, here is what you must
1373 1. Make sure you have a version of Make that supports the `VPATH'
1374 feature. (GNU Make supports it, as do Make versions on most BSD
1377 2. If you have ever run `configure' in the source directory, you must
1378 undo the configuration. Do this by running:
1382 3. Go to the directory in which you want to build the compiler before
1383 running `configure':
1388 On systems that do not support symbolic links, this directory must
1389 be on the same file system as the source code directory.
1391 4. Specify where to find `configure' when you run it:
1393 ../gcc/configure ...
1395 This also tells `configure' where to find the compiler sources;
1396 `configure' takes the directory from the file name that was used to
1397 invoke it. But if you want to be sure, you can specify the source
1398 directory with the `--srcdir' option, like this:
1400 ../gcc/configure --srcdir=../gcc OTHER OPTIONS
1402 The directory you specify with `--srcdir' need not be the same as
1403 the one that `configure' is found in.
1405 Now, you can run `make' in that directory. You need not repeat the
1406 configuration steps shown above, when ordinary source files change. You
1407 must, however, run `configure' again when the configuration files
1408 change, if your system does not support symbolic links.
1410 Building and Installing a Cross-Compiler
1411 ========================================
1413 GNU CC can function as a cross-compiler for many machines, but not
1416 * Cross-compilers for the Mips as target using the Mips assembler
1417 currently do not work, because the auxiliary programs
1418 `mips-tdump.c' and `mips-tfile.c' can't be compiled on anything
1419 but a Mips. It does work to cross compile for a Mips if you use
1420 the GNU assembler and linker.
1422 * Cross-compilers between machines with different floating point
1423 formats have not all been made to work. GNU CC now has a floating
1424 point emulator with which these can work, but each target machine
1425 description needs to be updated to take advantage of it.
1427 * Cross-compilation between machines of different word sizes is
1428 somewhat problematic and sometimes does not work.
1430 Since GNU CC generates assembler code, you probably need a
1431 cross-assembler that GNU CC can run, in order to produce object files.
1432 If you want to link on other than the target machine, you need a
1433 cross-linker as well. You also need header files and libraries suitable
1434 for the target machine that you can install on the host machine.
1436 Steps of Cross-Compilation
1437 --------------------------
1439 To compile and run a program using a cross-compiler involves several
1442 * Run the cross-compiler on the host machine to produce assembler
1443 files for the target machine. This requires header files for the
1446 * Assemble the files produced by the cross-compiler. You can do this
1447 either with an assembler on the target machine, or with a
1448 cross-assembler on the host machine.
1450 * Link those files to make an executable. You can do this either
1451 with a linker on the target machine, or with a cross-linker on the
1452 host machine. Whichever machine you use, you need libraries and
1453 certain startup files (typically `crt....o') for the target
1456 It is most convenient to do all of these steps on the same host
1457 machine, since then you can do it all with a single invocation of GNU
1458 CC. This requires a suitable cross-assembler and cross-linker. For
1459 some targets, the GNU assembler and linker are available.
1461 Configuring a Cross-Compiler
1462 ----------------------------
1464 To build GNU CC as a cross-compiler, you start out by running
1465 `configure'. Use the `--target=TARGET' to specify the target type. If
1466 `configure' was unable to correctly identify the system you are running
1467 on, also specify the `--build=BUILD' option. For example, here is how
1468 to configure for a cross-compiler that produces code for an HP 68030
1469 system running BSD on a system that `configure' can correctly identify:
1471 ./configure --target=m68k-hp-bsd4.3
1473 Tools and Libraries for a Cross-Compiler
1474 ----------------------------------------
1476 If you have a cross-assembler and cross-linker available, you should
1477 install them now. Put them in the directory `/usr/local/TARGET/bin'.
1478 Here is a table of the tools you should put in this directory:
1481 This should be the cross-assembler.
1484 This should be the cross-linker.
1487 This should be the cross-archiver: a program which can manipulate
1488 archive files (linker libraries) in the target machine's format.
1491 This should be a program to construct a symbol table in an archive
1494 The installation of GNU CC will find these programs in that
1495 directory, and copy or link them to the proper place to for the
1496 cross-compiler to find them when run later.
1498 The easiest way to provide these files is to build the Binutils
1499 package and GAS. Configure them with the same `--host' and `--target'
1500 options that you use for configuring GNU CC, then build and install
1501 them. They install their executables automatically into the proper
1502 directory. Alas, they do not support all the targets that GNU CC
1505 If you want to install libraries to use with the cross-compiler,
1506 such as a standard C library, put them in the directory
1507 `/usr/local/TARGET/lib'; installation of GNU CC copies all the files in
1508 that subdirectory into the proper place for GNU CC to find them and
1509 link with them. Here's an example of copying some libraries from a
1513 lcd /usr/local/TARGET/lib
1521 The precise set of libraries you'll need, and their locations on the
1522 target machine, vary depending on its operating system.
1524 Many targets require "start files" such as `crt0.o' and `crtn.o'
1525 which are linked into each executable; these too should be placed in
1526 `/usr/local/TARGET/lib'. There may be several alternatives for
1527 `crt0.o', for use with profiling or other compilation options. Check
1528 your target's definition of `STARTFILE_SPEC' to find out what start
1529 files it uses. Here's an example of copying these files from a target
1533 lcd /usr/local/TARGET/lib
1541 `libgcc.a' and Cross-Compilers
1542 ------------------------------
1544 Code compiled by GNU CC uses certain runtime support functions
1545 implicitly. Some of these functions can be compiled successfully with
1546 GNU CC itself, but a few cannot be. These problem functions are in the
1547 source file `libgcc1.c'; the library made from them is called
1550 When you build a native compiler, these functions are compiled with
1551 some other compiler-the one that you use for bootstrapping GNU CC.
1552 Presumably it knows how to open code these operations, or else knows how
1553 to call the run-time emulation facilities that the machine comes with.
1554 But this approach doesn't work for building a cross-compiler. The
1555 compiler that you use for building knows about the host system, not the
1558 So, when you build a cross-compiler you have to supply a suitable
1559 library `libgcc1.a' that does the job it is expected to do.
1561 To compile `libgcc1.c' with the cross-compiler itself does not work.
1562 The functions in this file are supposed to implement arithmetic
1563 operations that GNU CC does not know how to open code for your target
1564 machine. If these functions are compiled with GNU CC itself, they will
1565 compile into infinite recursion.
1567 On any given target, most of these functions are not needed. If GNU
1568 CC can open code an arithmetic operation, it will not call these
1569 functions to perform the operation. It is possible that on your target
1570 machine, none of these functions is needed. If so, you can supply an
1571 empty library as `libgcc1.a'.
1573 Many targets need library support only for multiplication and
1574 division. If you are linking with a library that contains functions for
1575 multiplication and division, you can tell GNU CC to call them directly
1576 by defining the macros `MULSI3_LIBCALL', and the like. These macros
1577 need to be defined in the target description macro file. For some
1578 targets, they are defined already. This may be sufficient to avoid the
1579 need for libgcc1.a; if so, you can supply an empty library.
1581 Some targets do not have floating point instructions; they need other
1582 functions in `libgcc1.a', which do floating arithmetic. Recent
1583 versions of GNU CC have a file which emulates floating point. With a
1584 certain amount of work, you should be able to construct a floating
1585 point emulator that can be used as `libgcc1.a'. Perhaps future
1586 versions will contain code to do this automatically and conveniently.
1587 That depends on whether someone wants to implement it.
1589 Some embedded targets come with all the necessary `libgcc1.a'
1590 routines written in C or assembler. These targets build `libgcc1.a'
1591 automatically and you do not need to do anything special for them.
1592 Other embedded targets do not need any `libgcc1.a' routines since all
1593 the necessary operations are supported by the hardware.
1595 If your target system has another C compiler, you can configure GNU
1596 CC as a native compiler on that machine, build just `libgcc1.a' with
1597 `make libgcc1.a' on that machine, and use the resulting file with the
1598 cross-compiler. To do this, execute the following on the target
1602 ./configure --host=sparc --target=sun3
1605 And then this on the host machine:
1613 Another way to provide the functions you need in `libgcc1.a' is to
1614 define the appropriate `perform_...' macros for those functions. If
1615 these definitions do not use the C arithmetic operators that they are
1616 meant to implement, you should be able to compile them with the
1617 cross-compiler you are building. (If these definitions already exist
1618 for your target file, then you are all set.)
1620 To build `libgcc1.a' using the perform macros, use
1621 `LIBGCC1=libgcc1.a OLDCC=./xgcc' when building the compiler.
1622 Otherwise, you should place your replacement library under the name
1623 `libgcc1.a' in the directory in which you will build the
1624 cross-compiler, before you run `make'.
1626 Cross-Compilers and Header Files
1627 --------------------------------
1629 If you are cross-compiling a standalone program or a program for an
1630 embedded system, then you may not need any header files except the few
1631 that are part of GNU CC (and those of your program). However, if you
1632 intend to link your program with a standard C library such as `libc.a',
1633 then you probably need to compile with the header files that go with
1634 the library you use.
1636 The GNU C compiler does not come with these files, because (1) they
1637 are system-specific, and (2) they belong in a C library, not in a
1640 If the GNU C library supports your target machine, then you can get
1641 the header files from there (assuming you actually use the GNU library
1642 when you link your program).
1644 If your target machine comes with a C compiler, it probably comes
1645 with suitable header files also. If you make these files accessible
1646 from the host machine, the cross-compiler can use them also.
1648 Otherwise, you're on your own in finding header files to use when
1651 When you have found suitable header files, put them in the directory
1652 `/usr/local/TARGET/include', before building the cross compiler. Then
1653 installation will run fixincludes properly and install the corrected
1654 versions of the header files where the compiler will use them.
1656 Provide the header files before you build the cross-compiler, because
1657 the build stage actually runs the cross-compiler to produce parts of
1658 `libgcc.a'. (These are the parts that *can* be compiled with GNU CC.)
1659 Some of them need suitable header files.
1661 Here's an example showing how to copy the header files from a target
1662 machine. On the target machine, do this:
1664 (cd /usr/include; tar cf - .) > tarfile
1666 Then, on the host machine, do this:
1669 lcd /usr/local/TARGET/include
1674 Actually Building the Cross-Compiler
1675 ------------------------------------
1677 Now you can proceed just as for compiling a single-machine compiler
1678 through the step of building stage 1. If you have not provided some
1679 sort of `libgcc1.a', then compilation will give up at the point where
1680 it needs that file, printing a suitable error message. If you do
1681 provide `libgcc1.a', then building the compiler will automatically
1682 compile and link a test program called `libgcc1-test'; if you get
1683 errors in the linking, it means that not all of the necessary routines
1684 in `libgcc1.a' are available.
1686 You must provide the header file `float.h'. One way to do this is
1687 to compile `enquire' and run it on your target machine. The job of
1688 `enquire' is to run on the target machine and figure out by experiment
1689 the nature of its floating point representation. `enquire' records its
1690 findings in the header file `float.h'. If you can't produce this file
1691 by running `enquire' on the target machine, then you will need to come
1692 up with a suitable `float.h' in some other way (or else, avoid using it
1695 Do not try to build stage 2 for a cross-compiler. It doesn't work to
1696 rebuild GNU CC as a cross-compiler using the cross-compiler, because
1697 that would produce a program that runs on the target machine, not on the
1698 host. For example, if you compile a 386-to-68030 cross-compiler with
1699 itself, the result will not be right either for the 386 (because it was
1700 compiled into 68030 code) or for the 68030 (because it was configured
1701 for a 386 as the host). If you want to compile GNU CC into 68030 code,
1702 whether you compile it on a 68030 or with a cross-compiler on a 386, you
1703 must specify a 68030 as the host when you configure it.
1705 To install the cross-compiler, use `make install', as usual.
1707 Installing GNU CC on the Sun
1708 ============================
1710 On Solaris (version 2.1), do not use the linker or other tools in
1711 `/usr/ucb' to build GNU CC. Use `/usr/ccs/bin'.
1713 Make sure the environment variable `FLOAT_OPTION' is not set when
1714 you compile `libgcc.a'. If this option were set to `f68881' when
1715 `libgcc.a' is compiled, the resulting code would demand to be linked
1716 with a special startup file and would not link properly without special
1719 There is a bug in `alloca' in certain versions of the Sun library.
1720 To avoid this bug, install the binaries of GNU CC that were compiled by
1721 GNU CC. They use `alloca' as a built-in function and never the one in
1724 Some versions of the Sun compiler crash when compiling GNU CC. The
1725 problem is a segmentation fault in cpp. This problem seems to be due to
1726 the bulk of data in the environment variables. You may be able to avoid
1727 it by using the following command to compile GNU CC with Sun CC:
1729 make CC="TERMCAP=x OBJS=x LIBFUNCS=x STAGESTUFF=x cc"
1731 SunOS 4.1.3 and 4.1.3_U1 have bugs that can cause intermittent core
1732 dumps when compiling GNU CC. A common symptom is an internal compiler
1733 error which does not recur if you run it again. To fix the problem,
1734 install Sun recommended patch 100726 (for SunOS 4.1.3) or 101508 (for
1735 SunOS 4.1.3_U1), or upgrade to a later SunOS release.
1737 Installing GNU CC on VMS
1738 ========================
1740 The VMS version of GNU CC is distributed in a backup saveset
1741 containing both source code and precompiled binaries.
1743 To install the `gcc' command so you can use the compiler easily, in
1744 the same manner as you use the VMS C compiler, you must install the VMS
1745 CLD file for GNU CC as follows:
1747 1. Define the VMS logical names `GNU_CC' and `GNU_CC_INCLUDE' to
1748 point to the directories where the GNU CC executables
1749 (`gcc-cpp.exe', `gcc-cc1.exe', etc.) and the C include files are
1750 kept respectively. This should be done with the commands:
1752 $ assign /system /translation=concealed -
1754 $ assign /system /translation=concealed -
1755 disk:[gcc.include.] gnu_cc_include
1757 with the appropriate disk and directory names. These commands can
1758 be placed in your system startup file so they will be executed
1759 whenever the machine is rebooted. You may, if you choose, do this
1760 via the `GCC_INSTALL.COM' script in the `[GCC]' directory.
1762 2. Install the `GCC' command with the command line:
1764 $ set command /table=sys$common:[syslib]dcltables -
1765 /output=sys$common:[syslib]dcltables gnu_cc:[000000]gcc
1766 $ install replace sys$common:[syslib]dcltables
1768 3. To install the help file, do the following:
1770 $ library/help sys$library:helplib.hlb gcc.hlp
1772 Now you can invoke the compiler with a command like `gcc /verbose
1773 file.c', which is equivalent to the command `gcc -v -c file.c' in
1776 If you wish to use GNU C++ you must first install GNU CC, and then
1777 perform the following steps:
1779 1. Define the VMS logical name `GNU_GXX_INCLUDE' to point to the
1780 directory where the preprocessor will search for the C++ header
1781 files. This can be done with the command:
1783 $ assign /system /translation=concealed -
1784 disk:[gcc.gxx_include.] gnu_gxx_include
1786 with the appropriate disk and directory name. If you are going to
1787 be using libg++, this is where the libg++ install procedure will
1788 install the libg++ header files.
1790 2. Obtain the file `gcc-cc1plus.exe', and place this in the same
1791 directory that `gcc-cc1.exe' is kept.
1793 The GNU C++ compiler can be invoked with a command like `gcc /plus
1794 /verbose file.cc', which is equivalent to the command `g++ -v -c
1797 We try to put corresponding binaries and sources on the VMS
1798 distribution tape. But sometimes the binaries will be from an older
1799 version than the sources, because we don't always have time to update
1800 them. (Use the `/version' option to determine the version number of
1801 the binaries and compare it with the source file `version.c' to tell
1802 whether this is so.) In this case, you should use the binaries you get
1803 to recompile the sources. If you must recompile, here is how:
1805 1. Execute the command procedure `vmsconfig.com' to set up the files
1806 `tm.h', `config.h', `aux-output.c', and `md.', and to create files
1807 `tconfig.h' and `hconfig.h'. This procedure also creates several
1808 linker option files used by `make-cc1.com' and a data file used by
1813 2. Setup the logical names and command tables as defined above. In
1814 addition, define the VMS logical name `GNU_BISON' to point at the
1815 to the directories where the Bison executable is kept. This
1816 should be done with the command:
1818 $ assign /system /translation=concealed -
1819 disk:[bison.] gnu_bison
1821 You may, if you choose, use the `INSTALL_BISON.COM' script in the
1822 `[BISON]' directory.
1824 3. Install the `BISON' command with the command line:
1826 $ set command /table=sys$common:[syslib]dcltables -
1827 /output=sys$common:[syslib]dcltables -
1828 gnu_bison:[000000]bison
1829 $ install replace sys$common:[syslib]dcltables
1831 4. Type `@make-gcc' to recompile everything (alternatively, submit
1832 the file `make-gcc.com' to a batch queue). If you wish to build
1833 the GNU C++ compiler as well as the GNU CC compiler, you must
1834 first edit `make-gcc.com' and follow the instructions that appear
1837 5. In order to use GCC, you need a library of functions which GCC
1838 compiled code will call to perform certain tasks, and these
1839 functions are defined in the file `libgcc2.c'. To compile this
1840 you should use the command procedure `make-l2.com', which will
1841 generate the library `libgcc2.olb'. `libgcc2.olb' should be built
1842 using the compiler built from the same distribution that
1843 `libgcc2.c' came from, and `make-gcc.com' will automatically do
1844 all of this for you.
1846 To install the library, use the following commands:
1848 $ library gnu_cc:[000000]gcclib/delete=(new,eprintf)
1849 $ library gnu_cc:[000000]gcclib/delete=L_*
1850 $ library libgcc2/extract=*/output=libgcc2.obj
1851 $ library gnu_cc:[000000]gcclib libgcc2.obj
1853 The first command simply removes old modules that will be replaced
1854 with modules from `libgcc2' under different module names. The
1855 modules `new' and `eprintf' may not actually be present in your
1856 `gcclib.olb'--if the VMS librarian complains about those modules
1857 not being present, simply ignore the message and continue on with
1858 the next command. The second command removes the modules that
1859 came from the previous version of the library `libgcc2.c'.
1861 Whenever you update the compiler on your system, you should also
1862 update the library with the above procedure.
1864 6. You may wish to build GCC in such a way that no files are written
1865 to the directory where the source files reside. An example would
1866 be the when the source files are on a read-only disk. In these
1867 cases, execute the following DCL commands (substituting your
1870 $ assign dua0:[gcc.build_dir.]/translation=concealed, -
1871 dua1:[gcc.source_dir.]/translation=concealed gcc_build
1872 $ set default gcc_build:[000000]
1874 where the directory `dua1:[gcc.source_dir]' contains the source
1875 code, and the directory `dua0:[gcc.build_dir]' is meant to contain
1876 all of the generated object files and executables. Once you have
1877 done this, you can proceed building GCC as described above. (Keep
1878 in mind that `gcc_build' is a rooted logical name, and thus the
1879 device names in each element of the search list must be an actual
1880 physical device name rather than another rooted logical name).
1882 7. *If you are building GNU CC with a previous version of GNU CC, you
1883 also should check to see that you have the newest version of the
1884 assembler*. In particular, GNU CC version 2 treats global constant
1885 variables slightly differently from GNU CC version 1, and GAS
1886 version 1.38.1 does not have the patches required to work with GCC
1887 version 2. If you use GAS 1.38.1, then `extern const' variables
1888 will not have the read-only bit set, and the linker will generate
1889 warning messages about mismatched psect attributes for these
1890 variables. These warning messages are merely a nuisance, and can
1893 If you are compiling with a version of GNU CC older than 1.33,
1894 specify `/DEFINE=("inline=")' as an option in all the
1895 compilations. This requires editing all the `gcc' commands in
1896 `make-cc1.com'. (The older versions had problems supporting
1897 `inline'.) Once you have a working 1.33 or newer GNU CC, you can
1898 change this file back.
1900 8. If you want to build GNU CC with the VAX C compiler, you will need
1901 to make minor changes in `make-cccp.com' and `make-cc1.com' to
1902 choose alternate definitions of `CC', `CFLAGS', and `LIBS'. See
1903 comments in those files. However, you must also have a working
1904 version of the GNU assembler (GNU as, aka GAS) as it is used as
1905 the back-end for GNU CC to produce binary object modules and is
1906 not included in the GNU CC sources. GAS is also needed to compile
1907 `libgcc2' in order to build `gcclib' (see above); `make-l2.com'
1908 expects to be able to find it operational in
1909 `gnu_cc:[000000]gnu-as.exe'.
1911 To use GNU CC on VMS, you need the VMS driver programs `gcc.exe',
1912 `gcc.com', and `gcc.cld'. They are distributed with the VMS
1913 binaries (`gcc-vms') rather than the GNU CC sources. GAS is also
1914 included in `gcc-vms', as is Bison.
1916 Once you have successfully built GNU CC with VAX C, you should use
1917 the resulting compiler to rebuild itself. Before doing this, be
1918 sure to restore the `CC', `CFLAGS', and `LIBS' definitions in
1919 `make-cccp.com' and `make-cc1.com'. The second generation
1920 compiler will be able to take advantage of many optimizations that
1921 must be suppressed when building with other compilers.
1923 Under previous versions of GNU CC, the generated code would
1924 occasionally give strange results when linked with the sharable
1925 `VAXCRTL' library. Now this should work.
1927 Even with this version, however, GNU CC itself should not be linked
1928 with the sharable `VAXCRTL'. The version of `qsort' in `VAXCRTL' has a
1929 bug (known to be present in VMS versions V4.6 through V5.5) which
1930 causes the compiler to fail.
1932 The executables are generated by `make-cc1.com' and `make-cccp.com'
1933 use the object library version of `VAXCRTL' in order to make use of the
1934 `qsort' routine in `gcclib.olb'. If you wish to link the compiler
1935 executables with the shareable image version of `VAXCRTL', you should
1936 edit the file `tm.h' (created by `vmsconfig.com') to define the macro
1939 `QSORT_WORKAROUND' is always defined when GNU CC is compiled with
1940 VAX C, to avoid a problem in case `gcclib.olb' is not yet available.
1945 Many target systems do not have support in the assembler and linker
1946 for "constructors"--initialization functions to be called before the
1947 official "start" of `main'. On such systems, GNU CC uses a utility
1948 called `collect2' to arrange to call these functions at start time.
1950 The program `collect2' works by linking the program once and looking
1951 through the linker output file for symbols with particular names
1952 indicating they are constructor functions. If it finds any, it creates
1953 a new temporary `.c' file containing a table of them, compiles it, and
1954 links the program a second time including that file.
1956 The actual calls to the constructors are carried out by a subroutine
1957 called `__main', which is called (automatically) at the beginning of
1958 the body of `main' (provided `main' was compiled with GNU CC). Calling
1959 `__main' is necessary, even when compiling C code, to allow linking C
1960 and C++ object code together. (If you use `-nostdlib', you get an
1961 unresolved reference to `__main', since it's defined in the standard
1962 GCC library. Include `-lgcc' at the end of your compiler command line
1963 to resolve this reference.)
1965 The program `collect2' is installed as `ld' in the directory where
1966 the passes of the compiler are installed. When `collect2' needs to
1967 find the *real* `ld', it tries the following file names:
1969 * `real-ld' in the directories listed in the compiler's search
1972 * `real-ld' in the directories listed in the environment variable
1975 * The file specified in the `REAL_LD_FILE_NAME' configuration macro,
1978 * `ld' in the compiler's search directories, except that `collect2'
1979 will not execute itself recursively.
1983 "The compiler's search directories" means all the directories where
1984 `gcc' searches for passes of the compiler. This includes directories
1985 that you specify with `-B'.
1987 Cross-compilers search a little differently:
1989 * `real-ld' in the compiler's search directories.
1991 * `TARGET-real-ld' in `PATH'.
1993 * The file specified in the `REAL_LD_FILE_NAME' configuration macro,
1996 * `ld' in the compiler's search directories.
1998 * `TARGET-ld' in `PATH'.
2000 `collect2' explicitly avoids running `ld' using the file name under
2001 which `collect2' itself was invoked. In fact, it remembers up a list
2002 of such names--in case one copy of `collect2' finds another copy (or
2003 version) of `collect2' installed as `ld' in a second place in the
2006 `collect2' searches for the utilities `nm' and `strip' using the
2007 same algorithm as above for `ld'.
2009 Standard Header File Directories
2010 ================================
2012 `GCC_INCLUDE_DIR' means the same thing for native and cross. It is
2013 where GNU CC stores its private include files, and also where GNU CC
2014 stores the fixed include files. A cross compiled GNU CC runs
2015 `fixincludes' on the header files in `$(tooldir)/include'. (If the
2016 cross compilation header files need to be fixed, they must be installed
2017 before GNU CC is built. If the cross compilation header files are
2018 already suitable for ANSI C and GNU CC, nothing special need be done).
2020 `GPLUS_INCLUDE_DIR' means the same thing for native and cross. It
2021 is where `g++' looks first for header files. `libg++' installs only
2022 target independent header files in that directory.
2024 `LOCAL_INCLUDE_DIR' is used only for a native compiler. It is
2025 normally `/usr/local/include'. GNU CC searches this directory so that
2026 users can install header files in `/usr/local/include'.
2028 `CROSS_INCLUDE_DIR' is used only for a cross compiler. GNU CC
2029 doesn't install anything there.
2031 `TOOL_INCLUDE_DIR' is used for both native and cross compilers. It
2032 is the place for other packages to install header files that GNU CC will
2033 use. For a cross-compiler, this is the equivalent of `/usr/include'.
2034 When you build a cross-compiler, `fixincludes' processes any header
2035 files in this directory.