install

gcc库的原代码,对编程有很大帮助.

     proper tools in the following stage.

     Alternatively, you can do subsequent compilation using a value of
     the `PATH' environment variable such that the necessary GNU tools
     come before the standard system tools.

 12. Recompile the compiler with itself, with this command:

          make CC="stage1/xgcc -Bstage1/" CFLAGS="-g -O2"

     This is called making the stage 2 compiler.

     The command shown above builds compilers for all the supported
     languages.  If you don't want them all, you can specify the
     languages to build by typing the argument `LANGUAGES="LIST"'.  LIST
     should contain one or more words from the list `c', `c++',
     `objective-c', and `proto'.  Separate the words with spaces.
     `proto' stands for the programs `protoize' and `unprotoize'; they
     are not a separate language, but you use `LANGUAGES' to enable or
     disable their installation.

     If you are going to build the stage 3 compiler, then you might
     want to build only the C language in stage 2.

     Once you have built the stage 2 compiler, if you are short of disk
     space, you can delete the subdirectory `stage1'.

     On a 68000 or 68020 system lacking floating point hardware, unless
     you have selected a `tm.h' file that expects by default that there
     is no such hardware, do this instead:

          make CC="stage1/xgcc -Bstage1/" CFLAGS="-g -O2 -msoft-float"

 13. If you wish to test the compiler by compiling it with itself one
     more time, install any other necessary GNU tools (such as GAS or
     the GNU linker) in the `stage2' subdirectory as you did in the
     `stage1' subdirectory, then do this:

          make stage2
          make CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O2"

     This is called making the stage 3 compiler.  Aside from the `-B'
     option, the compiler options should be the same as when you made
     the stage 2 compiler.  But the `LANGUAGES' option need not be the
     same.  The command shown above builds compilers for all the
     supported languages; if you don't want them all, you can specify
     the languages to build by typing the argument `LANGUAGES="LIST"',
     as described above.

     If you do not have to install any additional GNU tools, you may
     use the command

          make bootstrap LANGUAGES=LANGUAGE-LIST BOOT_CFLAGS=OPTION-LIST

     instead of making `stage1', `stage2', and performing the two
     compiler builds.

 14. Then compare the latest object files with the stage 2 object
     files--they ought to be identical, aside from time stamps (if any).

     On some systems, meaningful comparison of object files is
     impossible; they always appear "different."  This is currently
     true on Solaris and some systems that use ELF object file format.
     On some versions of Irix on SGI machines and DEC Unix (OSF/1) on
     Alpha systems, you will not be able to compare the files without
     specifying `-save-temps'; see the description of individual
     systems above to see if you get comparison failures.  You may have
     similar problems on other systems.

     Use this command to compare the files:

          make compare

     This will mention any object files that differ between stage 2 and
     stage 3.  Any difference, no matter how innocuous, indicates that
     the stage 2 compiler has compiled GNU CC incorrectly, and is
     therefore a potentially serious bug which you should investigate
     and report.

     If your system does not put time stamps in the object files, then
     this is a faster way to compare them (using the Bourne shell):

          for file in *.o; do
          cmp $file stage2/$file
          done

     If you have built the compiler with the `-mno-mips-tfile' option on
     MIPS machines, you will not be able to compare the files.

 15. Install the compiler driver, the compiler's passes and run-time
     support with `make install'.  Use the same value for `CC',
     `CFLAGS' and `LANGUAGES' that you used when compiling the files
     that are being installed.  One reason this is necessary is that
     some versions of Make have bugs and recompile files gratuitously
     when you do this step.  If you use the same variable values, those
     files will be recompiled properly.

     For example, if you have built the stage 2 compiler, you can use
     the following command:

          make install CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O" LANGUAGES="LIST"

     This copies the files `cc1', `cpp' and `libgcc.a' to files `cc1',
     `cpp' and `libgcc.a' in the directory
     `/usr/local/lib/gcc-lib/TARGET/VERSION', which is where the
     compiler driver program looks for them.  Here TARGET is the target
     machine type specified when you ran `configure', and VERSION is
     the version number of GNU CC.  This naming scheme permits various
     versions and/or cross-compilers to coexist.

     This also copies the driver program `xgcc' into
     `/usr/local/bin/gcc', so that it appears in typical execution
     search paths.

     On some systems, this command causes recompilation of some files.
     This is usually due to bugs in `make'.  You should either ignore
     this problem, or use GNU Make.

     *Warning: there is a bug in `alloca' in the Sun library.  To avoid
     this bug, be sure to install the executables of GNU CC that were
     compiled by GNU CC.  (That is, the executables from stage 2 or 3,
     not stage 1.)  They use `alloca' as a built-in function and never
     the one in the library.*

     (It is usually better to install GNU CC executables from stage 2
     or 3, since they usually run faster than the ones compiled with
     some other compiler.)

 16. If you're going to use C++, it's likely that you need to also
     install the libg++ distribution.  It should be available from the
     same place where you got the GNU C distribution.  Just as GNU C
     does not distribute a C runtime library, it also does not include
     a C++ run-time library.  All I/O functionality, special class
     libraries, etc., are available in the libg++ distribution.

Configurations Supported by GNU CC
==================================

   Here are the possible CPU types:

     1750a, a29k, alpha, arm, cN, clipper, dsp16xx, elxsi, h8300,
     hppa1.0, hppa1.1, i370, i386, i486, i586, i860, i960, m68000, m68k,
     m88k, mips, mipsel, mips64, mips64el, ns32k, powerpc, powerpcle,
     pyramid, romp, rs6000, sh, sparc, sparclite, sparc64, vax, we32k.

   Here are the recognized company names.  As you can see, customary
abbreviations are used rather than the longer official names.

     acorn, alliant, altos, apollo, att, bull, cbm, convergent, convex,
     crds, dec, dg, dolphin, elxsi, encore, harris, hitachi, hp, ibm,
     intergraph, isi, mips, motorola, ncr, next, ns, omron, plexus,
     sequent, sgi, sony, sun, tti, unicom, wrs.

   The company name is meaningful only to disambiguate when the rest of
the information supplied is insufficient.  You can omit it, writing
just `CPU-SYSTEM', if it is not needed.  For example, `vax-ultrix4.2'
is equivalent to `vax-dec-ultrix4.2'.

   Here is a list of system types:

     386bsd, aix, acis, amigados, aos, aout, bosx, bsd, clix, coff,
     ctix, cxux, dgux, dynix, ebmon, ecoff, elf, esix, freebsd, hms,
     genix, gnu, gnu/linux, hiux, hpux, iris, irix, isc, luna, lynxos,
     mach, minix, msdos, mvs, netbsd, newsos, nindy, ns, osf, osfrose,
     ptx, riscix, riscos, rtu, sco, sim, solaris, sunos, sym, sysv,
     udi, ultrix, unicos, uniplus, unos, vms, vsta, vxworks, winnt,
     xenix.

You can omit the system type; then `configure' guesses the operating
system from the CPU and company.

   You can add a version number to the system type; this may or may not
make a difference.  For example, you can write `bsd4.3' or `bsd4.4' to
distinguish versions of BSD.  In practice, the version number is most
needed for `sysv3' and `sysv4', which are often treated differently.

   If you specify an impossible combination such as `i860-dg-vms', then
you may get an error message from `configure', or it may ignore part of
the information and do the best it can with the rest.  `configure'
always prints the canonical name for the alternative that it used.  GNU
CC does not support all possible alternatives.

   Often a particular model of machine has a name.  Many machine names
are recognized as aliases for CPU/company combinations.  Thus, the
machine name `sun3', mentioned above, is an alias for `m68k-sun'.
Sometimes we accept a company name as a machine name, when the name is
popularly used for a particular machine.  Here is a table of the known
machine names:

     3300, 3b1, 3bN, 7300, altos3068, altos, apollo68, att-7300,
     balance, convex-cN, crds, decstation-3100, decstation, delta,
     encore, fx2800, gmicro, hp7NN, hp8NN, hp9k2NN, hp9k3NN, hp9k7NN,
     hp9k8NN, iris4d, iris, isi68, m3230, magnum, merlin, miniframe,
     mmax, news-3600, news800, news, next, pbd, pc532, pmax, powerpc,
     powerpcle, ps2, risc-news, rtpc, sun2, sun386i, sun386, sun3,
     sun4, symmetry, tower-32, tower.

Remember that a machine name specifies both the cpu type and the company
name.  If you want to install your own homemade configuration files,
you can use `local' as the company name to access them.  If you use
configuration `CPU-local', the configuration name without the cpu prefix
is used to form the configuration file names.

   Thus, if you specify `m68k-local', configuration uses files
`m68k.md', `local.h', `m68k.c', `xm-local.h', `t-local', and `x-local',
all in the directory `config/m68k'.

   Here is a list of configurations that have special treatment or
special things you must know:

`1750a-*-*'
     MIL-STD-1750A processors.

     Starting with GCC 2.6.1, the MIL-STD-1750A cross configuration no
     longer supports the Tektronix Assembler, but instead produces
     output for `as1750', an assembler/linker available under the GNU
     Public License for the 1750A. Contact *[e-mail]*
     for more details on obtaining `as1750'.  A similarly licensed
     simulator for the 1750A is available from same address.

     You should ignore a fatal error during the building of libgcc
     (libgcc is not yet implemented for the 1750A.)

     The `as1750' assembler requires the file `ms1750.inc', which is
     found in the directory `config/1750a'.

     GNU CC produced the same sections as the Fairchild F9450 C
     Compiler, namely:

    `Normal'
          The program code section.

    `Static'
          The read/write (RAM) data section.

    `Konst'
          The read-only (ROM) constants section.

    `Init'
          Initialization section (code to copy KREL to SREL).

     The smallest addressable unit is 16 bits (BITS_PER_UNIT is 16).
     This means that type `char' is represented with a 16-bit word per
     character.  The 1750A's "Load/Store Upper/Lower Byte" instructions
     are not used by GNU CC.

`alpha-*-osf1'
     Systems using processors that implement the DEC Alpha architecture
     and are running the DEC Unix (OSF/1) operating system, for example
     the DEC Alpha AXP systems.  (VMS on the Alpha is not currently
     supported by GNU CC.)

     GNU CC writes a `.verstamp' directive to the assembler output file
     unless it is built as a cross-compiler.  It gets the version to
     use from the system header file `/usr/include/stamp.h'.  If you
     install a new version of DEC Unix, you should rebuild GCC to pick
     up the new version stamp.

     Note that since the Alpha is a 64-bit architecture,
     cross-compilers from 32-bit machines will not generate code as
     efficient as that generated when the compiler is running on a
     64-bit machine because many optimizations that depend on being
     able to represent a word on the target in an integral value on the
     host cannot be performed.  Building cross-compilers on the Alpha
     for 32-bit machines has only been tested in a few cases and may
     not work properly.

     `make compare' may fail on old versions of DEC Unix unless you add
     `-save-temps' to `CFLAGS'.  On these systems, the name of the
     assembler input file is stored in the object file, and that makes
     comparison fail if it differs between the `stage1' and `stage2'
     compilations.  The option `-save-temps' forces a fixed name to be
     used for the assembler input file, instead of a randomly chosen
     name in `/tmp'.  Do not add `-save-temps' unless the comparisons
     fail without that option.  If you add `-save-temps', you will have
     to manually delete the `.i' and `.s' files after each series of
     compilations.

     GNU CC now supports both the native (ECOFF) debugging format used
     by DBX and GDB and an encapsulated STABS format for use only with
     GDB.  See the discussion of the `--with-stabs' option of
     `configure' above for more information on these formats and how to
     select them.

     There is a bug in DEC's assembler that produces incorrect line
     numbers for ECOFF format when the `.align' directive is used.  To
     work around this problem, GNU CC will not emit such alignment
     directives while writing ECOFF format debugging information even
     if optimization is being performed.  Unfortunately, this has the
     very undesirable side-effect that code addresses when `-O' is
     specified are different depending on whether or not `-g' is also
     specified.

     To avoid this behavior, specify `-gstabs+' and use GDB instead of