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The following information describes how to install g77.
The information in this file generally pertains to dealing
with source distributions of g77 and gcc.
It is possible that some of this information will be applicable
to some binary distributions of these products--however,
since these distributions are not made by the maintainers of
g77, responsibility for binary distributions rests with
whoever built and first distributed them.
Nevertheless, efforts to make g77 easier to both build
and install from source and package up as a binary distribution
are ongoing.
The procedures described to unpack, configure, build, and
install g77 assume your system has certain programs
already installed.
The following prerequisites should be met by your
system before you follow the g77 installation instructions:
gzip and tar
gcc and g77 distributions,
you'll need the gunzip utility in the gzip
distribution.
Most UNIX systems already have gzip installed.
If yours doesn't, you can get it from the FSF.
Note that you'll need tar and other utilities
as well, but all UNIX systems have these.
There are GNU versions of all these available--in fact,
a complete GNU UNIX system can be put together on
most systems, if desired.
The version of GNU gzip used to package this release
is 1.2.4.
(The version of GNU tar used to package this release
is 1.12.)
gcc on your system.
The version should be an exact copy of a distribution
from the FSF.
Its size is approximately 8.4MB.
If you've already unpacked `gcc-2.8.1.tar.gz' into a
directory (named `gcc-2.8.1') called the source tree
for gcc, you can delete the distribution
itself, but you'll need to remember to skip any instructions to unpack
this distribution.
Without an applicable gcc source tree, you cannot
build g77.
You can obtain an FSF distribution of gcc from the FSF.
g77 from the FSF,
the same way you obtained gcc.
g77 depends on the type of system you're
using, how you build g77, and how much of it you
install (primarily, which languages you install).
The sizes shown below assume all languages distributed
in gcc-2.8.1, plus g77, will be built
and installed.
These sizes are indicative of GNU/Linux systems on
Intel x86 running COFF and on Digital Alpha (AXP) systems
running ELF.
These should be fairly representative of 32-bit and 64-bit
systems, respectively.
Note that all sizes are approximate and subject to change without
notice!
They are based on preliminary releases of g77 made shortly
before the public beta release.
gcc and g77 distributions occupy 10MB
packed, 40MB unpacked.
These consist of the source code and documentation,
plus some derived files (mostly documentation), for
gcc and g77.
Any deviations from these numbers for different
kinds of systems are likely to be very minor.
gcc compiler modified and used to build itself for
testing fairly quickly, using the copy of the compiler
kept in gcc/stage2.
make is used to avoid
gratuitous rebuilds (or, the installation can be done
by hand).
gcc and g77 copies
23MB onto the `--prefix' disk for a total of 103MB
on an ix86, and copies 31MB onto the `--prefix'
disk for a total of 130MB on an Alpha.
gcc or g77 are planned, the
source and build directory may be removed, leaving
the total impact on a system's disk storage as
that of the amount copied during installation.
Systems with the appropriate version of gcc
installed don't require the complete
bootstrap build.
Doing a "straight build" requires about as much
space as does a bootstrap build followed by removing
both the `gcc/stage1' and `gcc/stage2'
directories.
Installing gcc and g77 over existing
versions might require less new disk space,
but note that, unlike many products, gcc
installs itself in a way that avoids overwriting other
installed versions of itself, so that other versions may
easily be invoked (via `gcc -V version').
So, the amount of space saved as a result of having
an existing version of gcc and g77
already installed is not much--typically only the
command drivers (gcc, g77, g++,
and so on, which are small) and the documentation
is overwritten by the new installation.
The rest of the new installation is done without
replacing existing installed versions (assuming
they have different version numbers).
make
make, and you will probably save
yourself a lot of trouble if it is GNU make (sometimes
referred to as gmake).
In particular, you probably need GNU make
to build outside the source directory
(with configure's `--srcdir' option.)
The version of GNU make used to develop this release
is 3.76.1.
cc
gcc
from the network or on CD-ROM,
perhaps from the FSF.
The best source of information about binaries
is probably a system-specific Usenet news group,
initially via its FAQ.
See section `Installing GNU CC' in Using and Porting GNU CC,
for more information on prerequisites for installing gcc.
sed
sed, but some have a broken
version that cannot handle configuring, building, or
installing gcc or g77.
The version of GNU sed used to develop this release
is 2.05.
(Note that GNU sed version 3.0 was withdrawn by the
FSF--if you happen to have this version installed, replace
it with version 2.05 immediately.
See a GNU distribution site for further explanation.)
root access or equivalent
root access to that system, or
equivalent access to the `--prefix' directory tree
specified on the configure command line.
Portions of the procedure (such as configuring and building
g77) can be performed by any user with enough disk
space and virtual memory.
However, these instructions are oriented towards less-experienced
users who want to install g77 on their own personal
systems.
System administrators with more experience will want to
determine for themselves how they want to modify the
procedures described below to suit the needs of their
installation.
autoconf
autoconf used to develop this release
is 2.12.
autoconf is not needed in the typical case of
installing gcc and g77.
See section Missing tools?, for information on when it
might be needed and how to work around not having it.
bison
bison used to develop this release
is 1.25.
bison is not needed in the typical case of
installing gcc and g77.
See section Missing tools?, for information on when it
might be needed and how to work around not having it.
gperf
gperf used to develop this release
is 2.5.
gperf is not needed in the typical case of
installing gcc and g77.
See section Missing tools?, for information on when it
might be needed and how to work around not having it.
makeinfo
makeinfo used to develop this release
is 1.68.
makeinfo is part of the GNU texinfo package;
makeinfo version 1.68
is distributed as part of
GNU texinfo version 3.11.
makeinfo is not needed in the typical case of
installing gcc and g77.
See section Missing tools?, for information on when it
might be needed and how to work around not having it.
An up-to-date version of GNU makeinfo is still convenient
when obtaining a new version of a GNU distribution such as
gcc or g77,
as it allows you to obtain the `.diff.gz' file
instead of the entire `.tar.gz' distribution
(assuming you have installed patch).
patch
patch used to develop this release
is 2.5.
Beginning with g77 version 0.5.23, it is no longer
necessary to patch the gcc back end to build g77.
An up-to-date version of GNU patch is still convenient
when obtaining a new version of a GNU distribution such as
gcc or g77,
as it allows you to obtain the `.diff.gz' file
instead of the entire `.tar.gz' distribution
(assuming you have installed the tools needed
to rebuild derived files, such as makeinfo).
This is a list of problems (and some apparent problems which don't really mean anything is wrong) that show up when configuring, building, installing, or porting GNU Fortran.
See section `Installation Problems' in Using and Porting GNU CC,
for more information on installation problems that can afflict
either gcc or g77.
These problems can occur on most or all systems.
Compiling g77 requires GNU C, not just ANSI C.
Fixing this wouldn't
be very hard (just tedious), but the code using GNU extensions to
the C language is expected to be rewritten for 0.6 anyway,
so there are no plans for an interim fix.
This requirement does not mean you must already have gcc
installed to build g77.
As long as you have a working C compiler, you can use a
bootstrap build to automate the process of first building
gcc using the working C compiler you have, then building
g77 and rebuilding gcc using that just-built gcc,
and so on.
g77 no longer requires application of a patch file
to the gcc compiler tree.
In fact, no such patch file is distributed with g77.
This is as of version 0.5.23.
It should be possible to build the runtime without building cc1
and other non-Fortran items, but, for now, an easy way to do that
is not yet established.
On SunOS4 systems, linking the f771 program used to
produce an error message concerning an undefined symbol named
`_strtoul', because the `strtoul' library function
is not provided on that system.
Other systems have, in the past, been reported to not provide their own `strtoul' or `bsearch' function.
Some versions g77 tried to default to providing bare-bones
versions of bsearch and strtoul automatically,
but every attempt at this has failed for at least one kind of system.
To limit the failures to those few systems actually missing the
required routines, the bare-bones versions are still provided,
in `gcc/f/proj.c',
if the appropriate macros are defined.
These are NEED_BSEARCH for `bsearch' and
NEED_STRTOUL for `NEED_STRTOUL'.
Therefore, if you are sure your system is missing
bsearch or strtoul in its library,
define the relevant macro(s) before building g77.
This can be done by editing `gcc/f/proj.c' and inserting
either or both of the following `#define' statements
before the comment shown:
/* Insert #define statements here. */ #define NEED_BSEARCH #define NEED_STRTOUL
Then, continue configuring and building g77 as usual.
Or, you can define these on the make command line.
To build with the bundled cc on SunOS4, for example, try:
make bootstrap BOOT_CFLAGS='-O2 -g -DNEED_STRTOUL'
If you then encounter problems compiling `gcc/f/proj.c', it might be due to a discrepancy between how `bsearch' or `strtoul' are defined by that file and how they're declared by your system's header files.
In that case, you'll have to use some basic knowledge of C to work around the problem, perhaps by editing `gcc/f/proj.c' somewhat.
It'd be helpful if g77's `Makefile.in' or `Make-lang.in'
would create the various `stagen' directories and their
subdirectories, so developers and expert installers wouldn't have to
reconfigure after cleaning up.
That help has arrived as of version 0.5.23 of g77.
Configuration itself no longer creates any particular directories
that are unique to g77.
The build procedures in `Make-lang.in' take care of
that, on demand.
Prior to version 0.5.23, g77 would sometimes ignore
the absence of `f77' and `F77' in the
`LANGUAGES' macro definition used for the
make command being processed.
As of version 0.5.23, g77 now obeys this macro
in all relevant situations.
However, in versions of gcc through 2.8.1,
non-g77 portions of gcc,
such as g++,
are known to go ahead and perform various
language-specific activities when their
respective language strings do not appear
in the `LANGUAGES' macro in effect
during that invocation of make.
It is expected that these remaining problems will
be fixed in a future version of gcc.
A linker bug on some versions of AIX 4.1 might prevent building.
See section LINKFAIL.
g77 has been in alpha testing since September of
1992, and in public beta testing since February of 1995.
Alpha testing was done by a small number of people worldwide on a fairly
wide variety of machines, involving self-compilation in most or
all cases.
Beta testing has been done primarily via self-compilation,
but in more and more cases, cross-compilation (and "criss-cross
compilation", where a version of a compiler is built on one machine
to run on a second and generate code that runs on a third) has
been tried and has succeeded, to varying extents.
Generally, g77 can be ported to any configuration to which
gcc, f2c, and libf2c can be ported and made
to work together, aside from the known problems described in this
manual.
If you want to port g77 to a particular configuration,
you should first make sure gcc and libf2c can be
ported to that configuration before focusing on g77, because
g77 is so dependent on them.
Even for cases where gcc and libf2c work,
you might run into problems with cross-compilation on certain machines,
for several reasons.
g77 as a cross-compiler in some cases,
though there are assumptions made during
configuration that probably make doing non-self-hosting builds
a hassle, requiring manual intervention.
gcc might still have some trouble being configured
for certain combinations of machines.
For example, it might not know how to handle floating-point
constants.
libg2c is built could make
building g77 as a cross-compiler easier--for example,
passing and using `$(LD)' and `$(AR)' in the appropriate
ways.
libg2c) for a target
system, depending on the systems involved in the configuration.
(This is a general problem with cross-compilation, and with
gcc in particular.)
Here are some internal g77 settings that can be changed
by editing source files in `gcc/f/' before building.
This information, and perhaps even these settings, represent
stop-gap solutions to problems people doing various ports
of g77 have encountered.
As such, none of the following information is expected to
be pertinent in future versions of g77.
As distributed, whether as part of f2c or g77,
libf2c accepts file unit numbers only in the range
0 through 99.
For example, a statement such as `WRITE (UNIT=100)' causes
a run-time crash in libf2c, because the unit number,
100, is out of range.
If you know that Fortran programs at your installation require the use of unit numbers higher than 99, you can change the value of the `MXUNIT' macro, which represents the maximum unit number, to an appropriately higher value.
To do this, edit the file `f/runtime/libI77/fio.h' in your
g77 source tree, changing the following line:
#define MXUNIT 100
Change the line so that the value of `MXUNIT' is defined to be at least one greater than the maximum unit number used by the Fortran programs on your system.
(For example, a program that does `WRITE (UNIT=255)' would require `MXUNIT' set to at least 256 to avoid crashing.)
Then build or rebuild g77 as appropriate.
Note: Changing this macro has no effect on other limits
your system might place on the number of files open at the same time.
That is, the macro might allow a program to do `WRITE (UNIT=100)',
but the library and operating system underlying libf2c might
disallow it if many other files have already been opened (via OPEN or
implicitly via READ, WRITE, and so on).
Information on how to increase these other limits should be found
in your system's documentation.
Some Fortran programs require output
(writes) to be flushed to the operating system (under UNIX,
via the fflush() library call) so that errors,
such as disk full, are immediately flagged via the relevant
ERR= and IOSTAT= mechanism, instead of such
errors being flagged later as subsequent writes occur, forcing
the previously written data to disk, or when the file is
closed.
Essentially, the difference can be viewed as synchronous error reporting (immediate flagging of errors during writes) versus asynchronous, or, more precisely, buffered error reporting (detection of errors might be delayed).
libg2c supports flagging write errors immediately when
it is built with the `ALWAYS_FLUSH' macro defined.
This results in a libg2c that runs slower, sometimes
quite a bit slower, under certain circumstances--for example,
accessing files via the networked file system NFS--but the
effect can be more reliable, robust file I/O.
If you know that Fortran programs requiring this level of precision
of error reporting are to be compiled using the
version of g77 you are building, you might wish to
modify the g77 source tree so that the version of
libg2c is built with the `ALWAYS_FLUSH' macro
defined, enabling this behavior.
To do this, find this line in `f/runtime/f2c.h' in
your g77 source tree:
/* #define ALWAYS_FLUSH */
Remove the leading `/* ', so the line begins with `#define', and the trailing ` */'.
Then build or rebuild g77 as appropriate.
g77, on most machines, puts many variables and arrays on the stack
where possible, and can be configured (by changing
`FFECOM_sizeMAXSTACKITEM' in `gcc/f/com.c') to force
smaller-sized entities into static storage (saving
on stack space) or permit larger-sized entities to be put on the
stack (which can improve run-time performance, as it presents
more opportunities for the GBE to optimize the generated code).
Note: Putting more variables and arrays on the stack might cause problems due to system-dependent limits on stack size. Also, the value of `FFECOM_sizeMAXSTACKITEM' has no effect on automatic variables and arrays. See section Bugs Not In GNU Fortran, for more information.
The g77 build will crash if an attempt is made to build
it as a cross-compiler
for a target when g77 cannot reliably determine the bit pattern of
floating-point constants for the target.
Planned improvements for version 0.6 of g77
will give it the capabilities it needs to not have to crash the build
but rather generate correct code for the target.
(Currently, g77
would generate bad code under such circumstances if it didn't crash
during the build, e.g. when compiling a source file that does
something like `EQUIVALENCE (I,R)' and `DATA R/9.43578/'.)
A warning message is issued when g77 sees code that provides
initial values (e.g. via DATA) to an aggregate area (COMMON
or EQUIVALENCE, or even a large enough array or CHARACTER
variable)
that is large enough to increase g77's compile time by roughly
a factor of 10.
This size currently is quite small, since g77
currently has a known bug requiring too much memory
and time to handle such cases.
In `gcc/f/data.c', the macro
`FFEDATA_sizeTOO_BIG_INIT_' is defined
to the minimum size for the warning to appear.
The size is specified in storage units,
which can be bytes, words, or whatever, on a case-by-case basis.
After changing this macro definition, you must
(of course) rebuild and reinstall g77 for
the change to take effect.
Note that, as of version 0.5.18, improvements have
reduced the scope of the problem for sparse
initialization of large arrays, especially those
with large, contiguous uninitialized areas.
However, the warning is issued at a point prior to
when g77 knows whether the initialization is sparse,
and delaying the warning could mean it is produced
too late to be helpful.
Therefore, the macro definition should not be adjusted to reflect sparse cases. Instead, adjust it to generate the warning when densely initialized arrays begin to cause responses noticeably slower than linear performance would suggest.
g77 used to warn when it was used to compile Fortran code
for a target configuration that is not basically a 32-bit
machine (such as an Alpha, which is a 64-bit machine, especially
if it has a 64-bit operating system running on it).
That was because g77 was known to not work
properly on such configurations.
As of version 0.5.20, g77 is believed to work well
enough on such systems.
So, the warning is no longer needed or provided.
However, support for 64-bit systems, especially in areas such as cross-compilation and handling of intrinsics, is still incomplete. The symptoms are believed to be compile-time diagnostics rather than the generation of bad code. It is hoped that version 0.6 will completely support 64-bit systems.
This procedure configures, builds, and installs g77
"out of the box" and works on most UNIX systems.
Each command is identified by a unique number,
used in the explanatory text that follows.
For the most part, the output of each command is not shown,
though indications of the types of responses are given in a
few cases.
To perform this procedure, the installer must be logged
in as user root.
Much of it can be done while not logged in as root,
and users experienced with UNIX administration should be
able to modify the procedure properly to do so.
Following traditional UNIX conventions, it is assumed that
the source trees for g77 and gcc will be
placed in `/usr/src'.
It also is assumed that the source distributions themselves
already reside in `/usr/FSF', a naming convention
used by the author of g77 on his own system:
/usr/FSF/gcc-2.8.1.tar.gz /usr/FSF/g77-0.5.23.tar.gz
If you vary any of the steps below, you might run into trouble, including possibly breaking existing programs for other users of your system. Before doing so, it is wise to review the explanations of some of the steps. These explanations follow this list of steps.
sh[ 1]# cd /usr/src sh[ 2]# gunzip -c < /usr/FSF/gcc-2.8.1.tar.gz | tar xf - [Might say "Broken pipe"...that is normal on some systems.] sh[ 3]# gunzip -c < /usr/FSF/g77-0.5.23.tar.gz | tar xf - ["Broken pipe" again possible.] sh[ 4]# ln -s gcc-2.8.1 gcc sh[ 5]# ln -s g77-0.5.23 g77 sh[ 6]# mv -i g77/* gcc [No questions should be asked by mv here; or, you made a mistake.] sh[ 7]# cd gcc sh[ 8]# ./configure --prefix=/usr [Do not do the above if gcc is not installed in /usr/bin. You might need a different --prefix=..., as described below.] sh[ 9]# make bootstrap [This takes a long time, and is where most problems occur.] sh[10]# make compare [This verifies that the compiler is `sane'. If any files are printed, you have likely found a g77 bug.] sh[11]# rm -fr stage1 sh[12]# make -k install [The actual installation.] sh[13]# g77 -v [Verify that g77 is installed, obtain version info.] sh[14]#
See section Updating Your Info Directory, for
information on how to update your system's top-level info
directory to contain a reference to this manual, so that
users of g77 can easily find documentation instead
of having to ask you for it.
Elaborations of many of the above steps follows:
g77 pretty much anyplace.
By convention, this manual assumes `/usr/src'.
It might be helpful if other users on your system
knew where to look for the source code for the
installed version of g77 and gcc in any case.
g77 as a complete `.tar.gz' file if you have
a complete, earlier distribution of g77.
If appropriate, you can unpack that earlier
version of g77, and then apply the appropriate patches
to achieve the same result--a source tree containing version
0.5.23 of g77.
g77.
See section Unpacking, for information on
using distributions of g77 made by organizations
other than the FSF.
g77 are
installed on your system.
See section Unpacking, for information
on the contents of the `g77' directory (as merged
into the `gcc' directory).
g77 and gcc documentation is
to be installed in `/usr/info/' and `/usr/man/',
and so on.
You should ensure that any existing installation of the `gcc'
executable is in `/usr/bin/'.
However, if that existing version of gcc is not 2.8.1,
or if you simply wish to avoid risking overwriting it with a
newly built copy of the same version,
you can specify `--prefix=/usr/local'
(which is the default)
or some other path,
and invoke the newly installed version
directly from that path's `bin' directory.
See section Where in the World Does Fortran (and GNU CC) Go?,
for more information on determining where to install g77.
See section Configuring GNU CC, for more information on the
configuration process triggered by invoking the `./configure'
script.
g77-specific
information on this step.
make -k install install-libf77Or, make sure you're using GNU
make.
See section Installation of Binaries, for more information.
See section Updating Your Info Directory,
for information on entering this manual into your
system's list of texinfo manuals.
g77 you just built and installed) and the
version numbers for the three parts of the libf2c
library (libF77, libI77, libU77), and
those version numbers are all in agreement, then there is
a high likelihood that the installation has been successfully
completed.
You might consider doing further testing.
For example, log in as a non-privileged user, then create
a small Fortran program, such as:
PROGRAM SMTEST
DO 10 I=1, 10
PRINT *, 'Hello World #', I
10 CONTINUE
END
Compile, link, and run the above program, and, assuming you named
the source file `smtest.f', the session should look like this:
sh# g77 -o smtest smtest.f sh# ./smtest Hello World # 1 Hello World # 2 Hello World # 3 Hello World # 4 Hello World # 5 Hello World # 6 Hello World # 7 Hello World # 8 Hello World # 9 Hello World # 10 sh#If invoking
g77 doesn't seem to work,
the problem might be that you've installed it in
a location that is not in your shell's search path.
For example, if you specified `--prefix=/gnu',
and `/gnu/bin' is not in your PATH
environment variable,
you must explicitly specify the location of the compiler
via /gnu/bin/g77 -o smtest smtest.f.
After proper installation, you don't
need to keep your gcc and g77 source and build directories
around anymore.
Removing them can free up a lot of disk space.
Here is the complete g77-specific information on how
to configure, build, and install g77.
The gcc source distribution is a stand-alone distribution.
It is designed to be unpacked (producing the gcc
source tree) and built as is, assuming certain
prerequisites are met (including the availability of compatible
UNIX programs such as make, cc, and so on).
However, before building gcc, you will want to unpack
and merge the g77 distribution in with it, so that you
build a Fortran-capable version of gcc, which includes
the g77 command, the necessary run-time libraries,
and this manual.
Unlike gcc, the g77 source distribution
is not a stand-alone distribution.
It is designed to be unpacked and, afterwards, immediately merged
into an applicable gcc source tree.
That is, the g77 distribution augments a
gcc distribution--without gcc, generally
only the documentation is immediately usable.
A sequence of commands typically used to unpack gcc
and g77 is:
sh# cd /usr/src sh# gunzip -c /usr/FSF/gcc-2.8.1.tar.gz | tar xf - sh# gunzip -c /usr/FSF/g77-0.5.23.tar.gz | tar xf - sh# ln -s gcc-2.8.1 gcc sh# ln -s g77-0.5.23 g77 sh# mv -i g77/* gcc
Notes: The commands beginning with `gunzip...' might
print `Broken pipe...' as they complete.
That is nothing to worry about, unless you actually
hear a pipe breaking.
The ln commands are helpful in reducing typing
and clutter in installation examples in this manual.
Hereafter, the top level of gcc source tree is referred to
as `gcc', and the top level of just the g77
source tree (prior to issuing the mv command, above)
is referred to as `g77'.
There are three top-level names in a g77 distribution:
g77/COPYING.g77 g77/README.g77 g77/f
All three entries should be moved (or copied) into a gcc
source tree (typically named after its version number and
as it appears in the FSF distributions--e.g. `gcc-2.8.1').
`g77/f' is the subdirectory containing all of the
code, documentation, and other information that is specific
to g77.
The other two files exist to provide information on g77
to someone encountering a gcc source tree with g77
already present, who has not yet read these installation
instructions and thus needs help understanding that the
source tree they are looking at does not come from a single
FSF distribution.
They also help people encountering an unmerged g77 source
tree for the first time.
Note: Please use only gcc and g77
source trees as distributed by the FSF.
Use of modified versions is likely to result in problems that appear to be
in the g77 code but, in fact, are not.
Do not use such modified versions
unless you understand all the differences between them and the versions
the FSF distributes--in which case you should be able to modify the
g77 (or gcc) source trees appropriately so g77
and gcc can coexist as they do in the stock FSF distributions.
After merging the g77 source tree into the gcc source tree,
you have put together a complete g77 source tree.
As of version 0.5.23, g77 no longer modifies
the version number of gcc,
nor does it patch gcc itself.
g77 still depends on being merged with an
appropriate version of gcc.
For version 0.5.23 of g77,
the specific version of gcc supported is 2.8.1.
However, other versions of gcc might be suitable
"hosts" for this version of g77.
GNU version numbers make it easy to figure out whether a particular version of a distribution is newer or older than some other version of that distribution. The format is, generally, major.minor.patch, with each field being a decimal number. (You can safely ignore leading zeros; for example, 1.5.3 is the same as 1.5.03.) The major field only increases with time. The other two fields are reset to 0 when the field to their left is incremented; otherwise, they, too, only increase with time. So, version 2.6.2 is newer than version 2.5.8, and version 3.0 is newer than both. (Trailing `.0' fields often are omitted in announcements and in names for distributions and the directories they create.)
If your version of gcc is older than the oldest version
supported by g77
(as casually determined by listing the contents of `gcc/f/INSTALL/',
which contains these installation instructions in plain-text format),
you should obtain a newer, supported version of gcc.
(You could instead obtain an older version of g77,
or try and get your g77 to work with the old
gcc, but neither approach is recommended, and
you shouldn't bother reporting any bugs you find if you
take either approach, because they're probably already
fixed in the newer versions you're not using.)
If your version of gcc is newer than the newest version
supported by g77, it is possible that your g77
will work with it anyway.
If the version number for gcc differs only in the
patch field, you might as well try that version of gcc.
Since it has the same major and minor fields,
the resulting combination is likely to work.
So, for example, if a particular version of g77 has support for
gcc versions 2.8.0 and 2.8.1,
it is likely that `gcc-2.8.2' would work well with g77.
However, `gcc-2.9.0' would almost certainly
not work with that version of g77
without appropriate modifications,
so a new version of g77 would be needed (and you should
wait for it rather than bothering the maintainers---see section User-visible Changes).
This complexity is the result of gcc and g77 being
separate distributions.
By keeping them separate, each product is able to be independently
improved and distributed to its user base more frequently.
However, the GBE interface defined by gcc typically
undergoes some incompatible changes at least every time the
minor field of the version number is incremented,
and such changes require corresponding changes to
the g77 front end (FFE).
Before configuring, you should make sure you know
where you want the g77 and gcc
binaries to be installed after they're built,
because this information is given to the configuration
tool and used during the build itself.
A g77 installation normally includes installation of
a Fortran-aware version of gcc, so that the gcc
command recognizes Fortran source files and knows how to compile
them.
For this to work, the version of gcc that you will be building
as part of g77 must be installed as the "active"
version of gcc on the system.
Sometimes people make the mistake of installing gcc as
`/usr/local/bin/gcc',
leaving an older, non-Fortran-aware version in `/usr/bin/gcc'.
(Or, the opposite happens.)
This can result in gcc being unable to compile Fortran
source files,
because when the older version of gcc is invoked,
it complains that it does not
recognize the language, or the file name suffix.
So, determine whether gcc already is installed on your system,
and, if so, where it is installed, and prepare to configure the
new version of gcc you'll be building so that it installs
over the existing version of gcc.
You might want to back up your existing copy of `/usr/bin/gcc', and the entire `/usr/lib' directory, before you perform the actual installation (as described in this manual).
Existing gcc installations typically are
found in `/usr' or `/usr/local'.
(This means the commands are installed in `/usr/bin' or
`/usr/local/bin',
the libraries in `/usr/lib' or `/usr/local/lib',
and so on.)
If you aren't certain where the currently
installed version of gcc and its
related programs reside, look at the output
of this command:
gcc -v -o /tmp/delete-me -xc /dev/null -xnone
All sorts of interesting information on the locations of various
gcc-related programs and data files should be visible
in the output of the above command.
(The output also is likely to include a diagnostic from
the linker, since there's no `main_()' function.)
However, you do have to sift through it yourself; gcc
currently provides no easy way to ask it where it is installed
and where it looks for the various programs and data files it
calls on to do its work.
Just building g77 should not overwrite any installed
programs--but, usually, after you build g77, you will want
to install it, so backing up anything it might overwrite is
a good idea.
(This is true for any package, not just g77,
though in this case it is intentional that g77 overwrites
gcc if it is already installed--it is unusual that
the installation process for one distribution intentionally
overwrites a program or file installed by another distribution,
although, in this case, g77 is an augmentation of the
gcc distribution.)
Another reason to back up the existing version first,
or make sure you can restore it easily, is that it might be
an older version on which other users have come to depend
for certain behaviors.
However, even the new version of gcc you install
will offer users the ability to specify an older version of
the actual compilation programs if desired, and these
older versions need not include any g77 components.
See section `Specifying Target Machine and Compiler Version' in Using and Porting GNU CC, for information on the `-V'
option of gcc.
g77 is configured automatically when you configure
gcc.
There are two parts of g77 that are configured in two
different ways---g77, which "camps on" to the
gcc configuration mechanism, and libg2c, which
uses a variation of the GNU autoconf configuration
system.
Generally, you shouldn't have to be concerned with
either g77 or libg2c configuration, unless
you're configuring g77 as a cross-compiler.
In this case, the libg2c configuration, and possibly the
g77 and gcc configurations as well,
might need special attention.
(This also might be the case if you're porting gcc to
a whole new system--even if it is just a new operating system
on an existing, supported CPU.)
To configure the system, see section `Installing GNU CC' in Using and Porting GNU CC, following the instructions for running `./configure'. Pay special attention to the `--prefix=' option, which you almost certainly will need to specify.
(Note that gcc installation information is provided
as a plain-text file in `gcc/INSTALL'.)
The information printed by the invocation of `./configure' should show that the `f' directory (the Fortran language) has been configured. If it does not, there is a problem.
Note: Configuring with the `--srcdir' argument,
or by starting in an empty directory
and typing a command such as ../gcc/configure to
build with separate build and source directories,
is known to work with GNU make,
but it is known to not work with other variants of make.
Irix5.2 and SunOS4.1 versions of make definitely
won't work outside the source directory at present.
g77's portion of the `configure' script
used to issue a warning message about this
when configuring for building binaries outside the source directory,
but no longer does this as of version 0.5.23.
Instead, g77 simply rejects most common attempts
to build it using a non-GNU make when the
build directory is not the same as the source directory,
issuing an explanatory diagnostic.
Building g77 requires building enough of gcc that
these instructions assume you're going to build all of
gcc, including g++, protoize, and so on.
You can save a little time and disk space by changes the
`LANGUAGES' macro definition in gcc/Makefile.in
or gcc/Makefile, but if you do that, you're on your own.
One change is almost certainly going to cause failures:
removing `c' or `f77' from the definition of the
`LANGUAGES' macro.
After configuring gcc, which configures g77 and
libg2c automatically, you're ready to start the actual
build by invoking make.
Note: You must have run the `configure'
script in gcc before you run make,
even if you're using an already existing gcc development directory,
because `./configure' does the work to recognize that you've added
g77 to the configuration.
There are two general approaches to building GNU CC from scratch:
gcc, that is then
used to compile ("bootstrap") the entire system.
On all systems without a recent version of gcc
already installed, the bootstrap method must be
used.
In particular, g77 uses extensions to the C
language offered, apparently, only by gcc.
On most systems with a recent version of gcc
already installed, the straight method can be
used.
This is an advantage, because it takes less CPU time
and disk space for the build.
However, it does require that the system have fairly
recent versions of many GNU programs and other
programs, which are not enumerated here.
A complete bootstrap build is done by issuing a command
beginning with `make bootstrap ...', as
described in section `Installing GNU CC' in Using and Porting GNU CC.
This is the most reliable form of build, but it does require
the most disk space and CPU time, since the complete system
is built twice (in Stages 2 and 3), after an initial build
(during Stage 1) of a minimal gcc compiler using
the native compiler and libraries.
You might have to, or want to, control the way a bootstrap
build is done by entering the make commands to build
each stage one at a time, as described in the gcc
manual.
For example, to save time or disk space, you might want
to not bother doing the Stage 3 build, in which case you
are assuming that the gcc compiler you have built
is basically sound (because you are giving up the opportunity
to compare a large number of object files to ensure they're
identical).
To save some disk space during installation, after Stage 2 is built, you can type `rm -fr stage1' to remove the binaries built during Stage 1.
Also, See section `Installing GNU CC' in Using and Porting GNU CC,
for important information on building gcc that is
not described in this g77 manual.
For example, explanations of diagnostic messages
and whether they're expected, or indicate trouble,
are found there.
If you have a recent version of gcc
already installed on your system, and if you're
reasonably certain it produces code that is
object-compatible with the version of gcc
you want to build as part of building g77,
you can save time and disk space by doing a straight
build.
To build just the compilers along with the necessary run-time libraries, issue the following command:
make -k CC=gcc
If you run into problems using this method, you have two options:
Especially if you do the latter, you might consider submitting any solutions as bug/fix reports. See section Known Causes of Trouble with GNU Fortran.
However, understand that many problems preventing a
straight build from working are not g77 problems,
and, in such cases, are not likely to be addressed in
future versions of g77.
Consider treating them as gcc bugs instead.
Before installing the system, which includes installing
gcc, you might want to do some minimum checking
to ensure that some basic things work.
Here are some commands you can try, and output typically printed by them when they work:
sh# cd /usr/src/gcc sh# ./g77 -B./ -v g77 version 0.5.23 Driving: ./g77 -B./ -v -c -xf77-version /dev/null -xnone Reading specs from ./specs gcc version 2.8.1 cpp -lang-c -v -isystem ./include -undef -D__GNUC__=2 ... GNU CPP version 2.8.1 (Alpha GNU/Linux with ELF) #include "..." search starts here: #include <...> search starts here: include /usr/alpha-linux/include /usr/lib/gcc-lib/alpha-linux/2.8.1/include /usr/include End of search list. ./f771 -fnull-version -quiet -dumpbase g77-version.f -version ... GNU F77 version 2.8.1 (alpha-linux) compiled ... GNU Fortran Front End version 0.5.23 as -nocpp -o /tmp/cca14485.o /tmp/cca14485.s ld -m elf64alpha -G 8 -O1 -dynamic-linker /lib/ld-linux.so.2 ... /tmp/cca14485 __G77_LIBF77_VERSION__: 0.5.23 @(#)LIBF77 VERSION 19970919 __G77_LIBI77_VERSION__: 0.5.23 @(#) LIBI77 VERSION pjw,dmg-mods 19980405 __G77_LIBU77_VERSION__: 0.5.23 @(#) LIBU77 VERSION 19970919 sh# ./xgcc -B./ -v -o /tmp/delete-me -xc /dev/null -xnone Reading specs from ./specs gcc version 2.8.1 ./cpp -lang-c -v -isystem ./include -undef ... GNU CPP version 2.8.1 (Alpha GNU/Linux with ELF) #include "..." search starts here: #include <...> search starts here: include /usr/alpha-linux/include /usr/lib/gcc-lib/alpha-linux/2.8.1/include /usr/include End of search list. ./cc1 /tmp/cca18063.i -quiet -dumpbase null.c -version ... GNU C version 2.8.1 (alpha-linux) compiled ... as -nocpp -o /tmp/cca180631.o /tmp/cca18063.s ld -m elf64alpha -G 8 -O1 -dynamic-linker /lib/ld-linux.so.2 ... /usr/lib/crt1.o: In function `_start': ../sysdeps/alpha/elf/start.S:77: undefined reference to `main' ../sysdeps/alpha/elf/start.S:77: undefined reference to `main' sh#
(Note that long lines have been truncated, and `...' used to indicate such truncations.)
The above two commands test whether g77 and gcc,
respectively, are able to compile empty (null) source files,
whether invocation of the C preprocessor works, whether libraries
can be linked, and so on.
If the output you get from either of the above two commands
is noticeably different, especially if it is shorter or longer
in ways that do not look consistent with the above sample
output, you probably should not install gcc and g77
until you have investigated further.
For example, you could try compiling actual applications and seeing how that works. (You might want to do that anyway, even if the above tests work.)
To compile using the not-yet-installed versions of gcc
and g77, use the following commands to invoke them.
To invoke g77, type:
/usr/src/gcc/g77 -B/usr/src/gcc/ ...
To invoke gcc, type:
/usr/src/gcc/xgcc -B/usr/src/gcc/ ...
After configuring, building, and testing g77 and gcc,
when you are ready to install them on your system, type:
make -k CC=gcc install
As described in section `Installing GNU CC' in Using and Porting GNU CC, the values for the `CC' and `LANGUAGES' macros should be the same as those you supplied for the build itself.
So, the details of the above command might vary if you used a bootstrap build (where you might be able to omit both definitions, or might have to supply the same definitions you used when building the final stage) or if you deviated from the instructions for a straight build.
If the above command does not install `libg2c.a' as expected, try this:
make -k ... install install-libf77
We don't know why some non-GNU versions of make sometimes
require this alternate command, but they do.
(Remember to supply the appropriate definition for `CC'
where you see `...' in the above command.)
Note that using the `-k' option tells make to
continue after some installation problems, like not having
makeinfo installed on your system.
It might not be necessary for your system.
Note: g77 no longer installs
files not directly part of g77,
such as `/usr/bin/f77', `/usr/lib/libf2c.a',
and `/usr/include/f2c.h', or their
`/usr/local' equivalents.
See section Distributing Binaries, for information on
how to accommodate systems with no existing non-g77
f77 compiler and systems with f2c installed.
As part of installing g77, you should make sure users
of info can easily access this manual on-line.
Do this by making sure a line such as the following exists
in `/usr/info/dir', or in whatever file is the top-level
file in the info directory on your system (perhaps
`/usr/local/info/dir':
* g77: (g77). The GNU Fortran programming language.
If the menu in `dir' is organized into sections, g77
probably belongs in a section with a name such as one of
the following:
A build of gcc might fail due to one or more tools
being called upon by make
(during the build or install process),
when those tools are not installed on your system.
This situation can result from any of the following actions (performed by you or someone else):
The reason these activities cause make to try and
invoke tools that it probably wouldn't when building
from a perfectly "clean" source directory containing
gcc and g77 is that some files in the
source directory (and the corresponding distribution)
aren't really source files, but derived files
that are produced by running tools with the corresponding
source files as input.
These derived files depend, in make terminology,
on the corresponding source files.
make determines that a file that depends on another
needs to be updated if the date-time-modified information for
the source file shows that it is newer than the corresponding
information for the derived file.
If it makes that determination, make runs the appropriate
commands (specified in the "Makefile") to update the
derived file, and this process typically calls upon one or
more installed tools to do the work.
The "safest" approach to dealing with this situation
is to recreate the gcc and g77 source
directories from complete gcc and g77 distributions
known to be provided by the FSF.
Another fairly "safe" approach is to simply install the tools you need to complete the build process. This is especially appropriate if you've changed the source code or applied a patch to do so.
However, if you're certain that the problem is limited entirely to incorrect date-time-modified information, that there are no discrepancies between the contents of source files and files derived from them in the source directory, you can often update the date-time-modified information for the derived files to work around the problem of not having the appropriate tools installed.
On UNIX systems, the simplest way to update the date-time-modified information of a file is to use the use the `touch' command.
How to use `touch' to update the derived files
updated by each of the tools is described below.
Note: New versions of g77 might change the set of
files it generates by invoking each of these tools.
If you cannot figure
out for yourself how to handle such a situation, try an
older version of g77 until you find someone who can
(or until you obtain and install the relevant tools).
autoconf?
If you cannot install autoconf, make sure you have started
with a fresh distribution of gcc and g77,
do not do `make maintainer-clean', and, to ensure that
autoconf is not invoked by make during the build,
type these commands:
sh# cd gcc/f/runtime sh# touch configure libU77/configure sh# cd ../../.. sh#
bison?
If you cannot install bison, make sure you have started
with a fresh distribution of gcc, do not
do `make maintainer-clean', and, to ensure that
bison is not invoked by make during the build,
type these commands:
sh# cd gcc sh# touch bi-parser.c bi-parser.h c-parse.c c-parse.h cexp.c sh# touch cp/parse.c cp/parse.h objc-parse.c sh# cd .. sh#
gperf?
If you cannot install gperf, make sure you have started
with a fresh distribution of gcc, do not
do `make maintainer-clean', and, to ensure that
gperf is not invoked by make during the build,
type these commands:
sh# cd gcc sh# touch c-gperf.h sh# cd .. sh#
makeinfo?
If makeinfo is needed but unavailable
when installing (via make install),
some files, like `libg2c.a',
might not be installed,
because once make determines that it cannot
invoke makeinfo, it cancels any further processing.
If you cannot install makeinfo, an easy work-around is to
specify `MAKEINFO=true' on the make command line,
or to specify the `-k' option (make -k install).
Another approach is to force the relevant files to be up-to-date by typing these commands and then re-trying the installation step:
sh# cd gcc sh# touch f/g77.info f/BUGS f/INSTALL f/NEWS sh# cd .. sh#
If you are building g77 for distribution to others in binary form,
first make sure you are aware of your legal responsibilities (read
the file `gcc/COPYING' thoroughly).
Then, consider your target audience and decide where g77 should
be installed.
For systems like GNU/Linux that have no native Fortran compiler (or
where g77 could be considered the native compiler for Fortran and
gcc for C, etc.), you should definitely configure
g77 for installation
in `/usr/bin' instead of `/usr/local/bin'.
Specify the
`--prefix=/usr' option when running `./configure'.
You might also want to set up the distribution
so the `f77' command is a link to `g77',
although a script that accepts "classic" UNIX f77
options and translates the command-line to the
appropriate g77 command line would be more appropriate.
If you do this, please also provide a "man page" in
`man/man1/f77.1' describing the command.
(A link to `man/man1/g77.1' is appropriate
if `bin/f77' is a link to `bin/g77'.)
For a system that might already have f2c installed,
consider whether inter-operation with g77 will be
important to users of f2c on that system.
If you want to improve the likelihood
that users will be able to use both f2c and g77
to compile code for a single program
without encountering link-time or run-time incompatibilities,
make sure that,
whenever they intend to combine f2c-produced code
with g77-produced code in an executable, they:
g77 build
in place of the `f2c.h' file
that normally comes with f2c
(or versions of g77 prior to 0.5.23)
when compiling all of the f2c-produced C code
lib/gcc-lib/.../libg2c.a library
built by the g77 build
instead of the `libf2c.a' library
that normally comes with f2c
(or versions of g77 prior to 0.5.23)
How you choose to effect the above depends on whether
the existing installation of f2c must be
maintained.
In any case, it is important to try and ensure that
the installation keeps working properly even after
subsequent re-installation of f2c,
which probably involves overwriting
`/usr/local/lib/libf2c.a' and
`/usr/local/include/f2c.h',
or similar.
At least, copying `libg2c.a' and `g2c.h' into
the appropriate "public" directories
allows users to more easily select the version of
libf2c they wish to use for a particular
build.
The names are changed by g77 to make this
coexistence easier to maintain;
even if f2c is installed later,
the g77 files normally installed
by its installation process aren't disturbed.
Use of symbolic links from one set of files to
another might result in problems after a subsequent
reinstallation of either f2c or g77,
so be sure to alert users of your distribution
accordingly.
(Make sure you clearly document, in the description of
your distribution, how installation of your distribution will
affect existing installations of gcc, f2c,
f77, `libf2c.a', and so on.
Similarly, you should clearly document any requirements
you assume will be met by users of your distribution.)
For other systems with native f77 (and cc) compilers,
configure g77 as you (or most of your audience) would
configure gcc for their installations.
Typically this is for installation in `/usr/local',
and would not include a new version of `/usr/bin/f77'
or `/usr/local/bin/f77',
so users could still use the native f77.
In any case, for g77 to work properly, you must ensure
that the binaries you distribute include:
gcc source tree into which a g77 source
tree was merged and configured, or it will not know how
to compile Fortran programs.
g77.
If it is not included, users will have trouble understanding
diagnostics messages and other such things, and will send
you a lot of email asking questions.
Please edit this documentation (by editing `gcc/f/*.texi'
and doing `make doc' from the `/usr/src/gcc' directory)
to reflect any changes you've made to g77, or at
least to encourage users of your binary distribution to
report bugs to you first.
Also, whether you distribute binaries or install g77
on your own system, it might be helpful for everyone to
add a line listing this manual by name and topic to the
top-level info node in `/usr/info/dir'.
That way, users can find g77 documentation more
easily.
See section Updating Your Info Directory.
g77.
It is not always kept up-to-date,
but you might as well include it
for people who really like "man" pages.
gcc, g77, g++,
and other GNU compilers.
g77-compiled programs.
Whether you want to include the slightly updated (and possibly improved) versions of `cc1', `cc1plus', and whatever other binaries get rebuilt with the changes the GNU Fortran distribution makes to the GNU back end, is up to you. These changes are highly unlikely to break any compilers, because they involve doing things like adding to the list of acceptable compiler options (so, for example, `cc1plus' accepts, and ignores, options that only `f771' actually processes).
Please assure users that unless they have a specific need for their existing, older versions of `gcc' command, they are unlikely to experience any problems by overwriting it with your version--though they could certainly protect themselves by making backup copies first!
Otherwise, users might try and install your binaries in a "safe" place, find they cannot compile Fortran programs with your distribution (because, perhaps, they're invoking their old version of the `gcc' command, which does not recognize Fortran programs), and assume that your binaries (or, more generally, GNU Fortran distributions in general) are broken, at least for their system.
Finally, please ask for bug reports to go to you first, at least
until you're sure your distribution is widely used and has been
well tested.
This especially goes for those of you making any
changes to the g77 sources to port g77, e.g. to OS/2.
fortran@gnu.org has received a fair number of bug
reports that turned out to be problems with other peoples' ports
and distributions, about which nothing could be done for the
user.
Once you are quite certain a bug report does not involve
your efforts, you can forward it to us.
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