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- Configurations: Configurations Supported by GNU CC.
- Other Dir: Compiling in a separate directory (not where the source is).
- Cross-Compiler: Building and installing a cross-compiler.
- Sun Install: See below for installation on the Sun.
- VMS Install: See below for installation on VMS.
- Collect2: How
collect2
works; how it finds ld
.
- Header Dirs: Understanding the standard header file directories.
Here is the procedure for installing GNU CC on a Unix system. See
section Installing GNU CC on VMS, for VMS systems. In this section we assume you
compile in the same directory that contains the source files; see
section Compilation in a Separate Directory, to find out how to compile in a separate directory on Unix
systems.
You cannot install GNU C by itself on MSDOS; it will not compile under
any MSDOS compiler except itself. You need to get the complete
compilation package DJGPP, which includes binaries as well as sources,
and includes all the necessary compilation tools and libraries.
-
If you have built GNU CC previously in the same directory for a
different target machine, do `make distclean' to delete all files
that might be invalid. One of the files this deletes is
`Makefile'; if `make distclean' complains that `Makefile'
does not exist, it probably means that the directory is already suitably
clean.
-
On a System V release 4 system, make sure `/usr/bin' precedes
`/usr/ucb' in
PATH
. The cc
command in
`/usr/ucb' uses libraries which have bugs.
-
Specify the host, build and target machine configurations. You do this
by running the file `configure'.
The build machine is the system which you are using, the
host machine is the system where you want to run the resulting
compiler (normally the build machine), and the target machine is
the system for which you want the compiler to generate code.
If you are building a compiler to produce code for the machine it runs
on (a native compiler), you normally do not need to specify any operands
to `configure'; it will try to guess the type of machine you are on
and use that as the build, host and target machines. So you don't need
to specify a configuration when building a native compiler unless
`configure' cannot figure out what your configuration is or guesses
wrong.
In those cases, specify the build machine's configuration name
with the `--build' option; the host and target will default to be
the same as the build machine. (If you are building a cross-compiler,
see section Building and Installing a Cross-Compiler.)
Here is an example:
./configure --build=sparc-sun-sunos4.1
A configuration name may be canonical or it may be more or less
abbreviated.
A canonical configuration name has three parts, separated by dashes.
It looks like this: `cpu-company-system'.
(The three parts may themselves contain dashes; `configure'
can figure out which dashes serve which purpose.) For example,
`m68k-sun-sunos4.1' specifies a Sun 3.
You can also replace parts of the configuration by nicknames or aliases.
For example, `sun3' stands for `m68k-sun', so
`sun3-sunos4.1' is another way to specify a Sun 3. You can also
use simply `sun3-sunos', since the version of SunOS is assumed by
default to be version 4. `sun3-bsd' also works, since
`configure' knows that the only BSD variant on a Sun 3 is SunOS.
You can specify a version number after any of the system types, and some
of the CPU types. In most cases, the version is irrelevant, and will be
ignored. So you might as well specify the version if you know it.
See section Configurations Supported by GNU CC, for a list of supported configuration names and
notes on many of the configurations. You should check the notes in that
section before proceeding any further with the installation of GNU CC.
There are four additional options you can specify independently to
describe variant hardware and software configurations. These are
`--with-gnu-as', `--with-gnu-ld', `--with-stabs' and
`--nfp'.
- `--with-gnu-as'
- If you will use GNU CC with the GNU assembler (GAS), you should declare
this by using the `--with-gnu-as' option when you run
`configure'.
Using this option does not install GAS. It only modifies the output of
GNU CC to work with GAS. Building and installing GAS is up to you.
Conversely, if you do not wish to use GAS and do not specify
`--with-gnu-as' when building GNU CC, it is up to you to make sure
that GAS is not installed. GNU CC searches for a program named
as
in various directories; if the program it finds is GAS, then
it runs GAS. If you are not sure where GNU CC finds the assembler it is
using, try specifying `-v' when you run it.
The systems where it makes a difference whether you use GAS are:
hppa1.0-any-any hppa1.1-any-any
i860-any-bsd m68k-bull-sysv m68k-hp-hpux
i386-any-sysv i386-any-isc
m68k-sony-bsd m68k-altos-sysv
m68000-hp-hpux m68000-att-sysv
any-lynx-lynxos mips-any
On any other system, `--with-gnu-as' has no effect.
On the systems listed above (except for the HP-PA, for ISC on the
386, and for `mips-sgi-irix5.*'), if you use GAS, you should also
use the GNU linker (and specify `--with-gnu-ld').
- `--with-gnu-ld'
- Specify the option `--with-gnu-ld' if you plan to use the GNU
linker with GNU CC.
This option does not cause the GNU linker to be installed; it just
modifies the behavior of GNU CC to work with the GNU linker.
Specifically, it inhibits the installation of
collect2
, a program
which otherwise serves as a front-end for the system's linker on most
configurations.
- `--with-stabs'
- On MIPS based systems and on Alphas, you must specify whether you want
GNU CC to create the normal ECOFF debugging format, or to use BSD-style
stabs passed through the ECOFF symbol table. The normal ECOFF debug
format cannot fully handle languages other than C. BSD stabs format can
handle other languages, but it only works with the GNU debugger GDB.
Normally, GNU CC uses the ECOFF debugging format by default; if you
prefer BSD stabs, specify `--with-stabs' when you configure GNU
CC.
No matter which default you choose when you configure GNU CC, the user
can use the `-gcoff' and `-gstabs+' options to specify explicitly
the debug format for a particular compilation.
`--with-stabs' is meaningful on the ISC system on the 386, also, if
`--with-gas' is used. It selects use of stabs debugging
information embedded in COFF output. This kind of debugging information
supports C++ well; ordinary COFF debugging information does not.
`--with-stabs' is also meaningful on 386 systems running SVR4. It
selects use of stabs debugging information embedded in ELF output. The
C++ compiler currently (2.6.0) does not support the DWARF debugging
information normally used on 386 SVR4 platforms; stabs provide a
workable alternative. This requires gas and gdb, as the normal SVR4
tools can not generate or interpret stabs.
- `--nfp'
- On certain systems, you must specify whether the machine has a floating
point unit. These systems include `m68k-sun-sunosn' and
`m68k-isi-bsd'. On any other system, `--nfp' currently has no
effect, though perhaps there are other systems where it could usefully
make a difference.
The `configure' script searches subdirectories of the source
directory for other compilers that are to be integrated into GNU CC.
The GNU compiler for C++, called G++ is in a subdirectory named
`cp'. `configure' inserts rules into `Makefile' to build
all of those compilers.
Here we spell out what files will be set up by configure
. Normally
you need not be concerned with these files.
-
A file named `config.h' is created that contains a `#include'
of the top-level config file for the machine you will run the compiler
on (see section `The Configuration File' in Using and Porting GCC). This file is responsible for defining information about the host
machine. It includes `tm.h'.
The top-level config file is located in the subdirectory `config'.
Its name is always `xm-something.h'; usually
`xm-machine.h', but there are some exceptions.
If your system does not support symbolic links, you might want to
set up `config.h' to contain a `#include' command which
refers to the appropriate file.
-
A file named `tconfig.h' is created which includes the top-level config
file for your target machine. This is used for compiling certain
programs to run on that machine.
-
A file named `tm.h' is created which includes the
machine-description macro file for your target machine. It should be in
the subdirectory `config' and its name is often
`machine.h'.
-
The command file `configure' also constructs the file
`Makefile' by adding some text to the template file
`Makefile.in'. The additional text comes from files in the
`config' directory, named `t-target' and
`x-host'. If these files do not exist, it means nothing
needs to be added for a given target or host.
-
The standard directory for installing GNU CC is `/usr/local/lib'.
If you want to install its files somewhere else, specify
`--prefix=dir' when you run `configure'. Here dir
is a directory name to use instead of `/usr/local' for all purposes
with one exception: the directory `/usr/local/include' is searched
for header files no matter where you install the compiler. To override
this name, use the
--local-prefix
option below.
-
Specify `--local-prefix=dir' if you want the compiler to
search directory `dir/include' for locally installed header
files instead of `/usr/local/include'.
You should specify `--local-prefix' only if your site has
a different convention (not `/usr/local') for where to put
site-specific files.
Do not specify `/usr' as the `--local-prefix'! The
directory you use for `--local-prefix' must not contain
any of the system's standard header files. If it did contain them,
certain programs would be miscompiled (including GNU Emacs, on certain
targets), because this would override and nullify the header file
corrections made by the
fixincludes
script.
-
Make sure the Bison parser generator is installed. (This is
unnecessary if the Bison output files `c-parse.c' and
`cexp.c' are more recent than `c-parse.y' and `cexp.y'
and you do not plan to change the `.y' files.)
Bison versions older than Sept 8, 1988 will produce incorrect output
for `c-parse.c'.
-
If you have chosen a configuration for GNU CC which requires other GNU
tools (such as GAS or the GNU linker) instead of the standard system
tools, install the required tools in the build directory under the names
`as', `ld' or whatever is appropriate. This will enable the
compiler to find the proper tools for compilation of the program
`enquire'.
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.
-
Build the compiler. Just type `make LANGUAGES=c' in the compiler
directory.
`LANGUAGES=c' specifies that only the C compiler should be
compiled. The makefile normally builds compilers for all the supported
languages; currently, C, C++ and Objective C. However, C is the only
language that is sure to work when you build with other non-GNU C
compilers. In addition, building anything but C at this stage is a
waste of time.
In general, you can specify the languages to build by typing the
argument `LANGUAGES="list"', where list is one or more
words from the list `c', `c++', and `objective-c'. If
you have any additional GNU compilers as subdirectories of the GNU CC
source directory, you may also specify their names in this list.
Ignore any warnings you may see about "statement not reached" in
`insn-emit.c'; they are normal. Also, warnings about "unknown
escape sequence" are normal in `genopinit.c' and perhaps some
other files. Likewise, you should ignore warnings about "constant is
so large that it is unsigned" in `insn-emit.c' and
`insn-recog.c'. Any other compilation errors may represent bugs in
the port to your machine or operating system, and
should be investigated and reported (see section Reporting Bugs).
Some commercial compilers fail to compile GNU CC because they have bugs
or limitations. For example, the Microsoft compiler is said to run out
of macro space. Some Ultrix compilers run out of expression space; then
you need to break up the statement where the problem happens.
-
If you are building a cross-compiler, stop here. See section Building and Installing a Cross-Compiler.
-
Move the first-stage object files and executables into a subdirectory
with this command:
make stage1
The files are moved into a subdirectory named `stage1'.
Once installation is complete, you may wish to delete these files
with rm -r stage1
.
-
If you have chosen a configuration for GNU CC which requires other GNU
tools (such as GAS or the GNU linker) instead of the standard system
tools, install the required tools in the `stage1' subdirectory
under the names `as', `ld' or whatever is appropriate. This
will enable the stage 1 compiler to find the 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.
-
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"
-
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.
-
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
probably on all systems that use ELF object file format. On some
versions of Irix on SGI machines and 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 (see section Reporting Bugs).
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.
-
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 command copies the three files `cc1', `cpp' and
`libgcc.a' into the files `cc1', `cpp' and
`libgcc.a' and puts them 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.)
-
Install the Objective C library (if you are installing the Objective C
compiler). Here is the command to do this:
make install-libobjc CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O"
-
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.
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