Using and Porting GNU CC
Using and Porting GNU CC
The VMS version of GNU CC is distributed in a backup saveset containing both source code and precompiled binaries.
To install the `gcc' command so you can use the compiler easily, in
the same manner as you use the VMS C compiler, you must install the VMS CLD
file for GNU CC as follows:
GNU_CC' and `GNU_CC_INCLUDE'
to point to the directories where the GNU CC executables
(`gcc-cpp.exe', `gcc-cc1.exe', etc.) and the C include files are
kept respectively. This should be done with the commands:
$ assign /system /translation=concealed - disk:[gcc.] gnu_cc $ assign /system /translation=concealed - disk:[gcc.include.] gnu_cc_include
with the appropriate disk and directory names. These commands can be
placed in your system startup file so they will be executed whenever
the machine is rebooted. You may, if you choose, do this via the
`GCC_INSTALL.COM' script in the `[GCC]' directory.
GCC' command with the command line:
$ set command /table=sys$common:[syslib]dcltables - /output=sys$common:[syslib]dcltables gnu_cc:[000000]gcc $ install replace sys$common:[syslib]dcltables
$ library/help sys$library:helplib.hlb gcc.hlp
Now you can invoke the compiler with a command like `gcc /verbose file.c', which is equivalent to the command `gcc -v -c file.c' in
Unix.
If you wish to use GNU C++ you must first install GNU CC, and then perform the following steps:
GNU_GXX_INCLUDE' to point to the
directory where the preprocessor will search for the C++ header files.
This can be done with the command:
$ assign /system /translation=concealed - disk:[gcc.gxx_include.] gnu_gxx_include
with the appropriate disk and directory name. If you are going to be using libg++, this is where the libg++ install procedure will install the libg++ header files.
gcc-cc1plus.exe', and place this in the same
directory that `gcc-cc1.exe' is kept.
The GNU C++ compiler can be invoked with a command like `gcc /plus /verbose file.cc', which is equivalent to the command `g++ -v -c file.cc' in Unix.
We try to put corresponding binaries and sources on the VMS distribution
tape. But sometimes the binaries will be from an older version than the
sources, because we don't always have time to update them. (Use the
`/version' option to determine the version number of the binaries and
compare it with the source file `version.c' to tell whether this is
so.) In this case, you should use the binaries you get to recompile the
sources. If you must recompile, here is how:
vmsconfig.com' to set up the files
`tm.h', `config.h', `aux-output.c', and `md.', and
to create files `tconfig.h' and `hconfig.h'. This procedure
also creates several linker option files used by `make-cc1.com' and
a data file used by `make-l2.com'.
$ @vmsconfig.com
GNU_BISON' to point at the
to the directories where the Bison executable is kept. This should be
done with the command:
$ assign /system /translation=concealed - disk:[bison.] gnu_bison
You may, if you choose, use the `INSTALL_BISON.COM' script in the
`[BISON]' directory.
BISON' command with the command line:
$ set command /table=sys$common:[syslib]dcltables - /output=sys$common:[syslib]dcltables - gnu_bison:[000000]bison $ install replace sys$common:[syslib]dcltables
@make-gcc' to recompile everything (alternatively, submit
the file `make-gcc.com' to a batch queue). If you wish to build
the GNU C++ compiler as well as the GNU CC compiler, you must first edit
`make-gcc.com' and follow the instructions that appear in the
comments.
libgcc2.c'. To compile this you should use the command procedure
`make-l2.com', which will generate the library `libgcc2.olb'.
`libgcc2.olb' should be built using the compiler built from
the same distribution that `libgcc2.c' came from, and
`make-gcc.com' will automatically do all of this for you.
To install the library, use the following commands:
$ library gnu_cc:[000000]gcclib/delete=(new,eprintf) $ library gnu_cc:[000000]gcclib/delete=L_* $ library libgcc2/extract=*/output=libgcc2.obj $ library gnu_cc:[000000]gcclib libgcc2.obj
The first command simply removes old modules that will be replaced with
modules from `libgcc2' under different module names. The modules
new and eprintf may not actually be present in your
`gcclib.olb'---if the VMS librarian complains about those modules
not being present, simply ignore the message and continue on with the
next command. The second command removes the modules that came from the
previous version of the library `libgcc2.c'.
Whenever you update the compiler on your system, you should also update the library with the above procedure.
$ assign dua0:[gcc.build_dir.]/translation=concealed, -
dua1:[gcc.source_dir.]/translation=concealed gcc_build
$ set default gcc_build:[000000]
where the directory `dua1:[gcc.source_dir]' contains the source
code, and the directory `dua0:[gcc.build_dir]' is meant to contain
all of the generated object files and executables. Once you have done
this, you can proceed building GCC as described above. (Keep in mind
that `gcc_build' is a rooted logical name, and thus the device
names in each element of the search list must be an actual physical
device name rather than another rooted logical name).
extern const variables will not have
the read-only bit set, and the linker will generate warning messages
about mismatched psect attributes for these variables. These warning
messages are merely a nuisance, and can safely be ignored.
If you are compiling with a version of GNU CC older than 1.33, specify
`/DEFINE=("inline=")' as an option in all the compilations. This
requires editing all the gcc commands in `make-cc1.com'.
(The older versions had problems supporting inline.) Once you
have a working 1.33 or newer GNU CC, you can change this file back.
make-cccp.com' and `make-cc1.com'
to choose alternate definitions of CC, CFLAGS, and
LIBS. See comments in those files. However, you must
also have a working version of the GNU assembler (GNU as, aka GAS) as
it is used as the back-end for GNU CC to produce binary object modules
and is not included in the GNU CC sources. GAS is also needed to
compile `libgcc2' in order to build `gcclib' (see above);
`make-l2.com' expects to be able to find it operational in
`gnu_cc:[000000]gnu-as.exe'.
To use GNU CC on VMS, you need the VMS driver programs
`gcc.exe', `gcc.com', and `gcc.cld'. They are
distributed with the VMS binaries (`gcc-vms') rather than the
GNU CC sources. GAS is also included in `gcc-vms', as is Bison.
Once you have successfully built GNU CC with VAX C, you should use the
resulting compiler to rebuild itself. Before doing this, be sure to
restore the CC, CFLAGS, and LIBS definitions in
`make-cccp.com' and `make-cc1.com'. The second generation
compiler will be able to take advantage of many optimizations that must
be suppressed when building with other compilers.
Under previous versions of GNU CC, the generated code would occasionally
give strange results when linked with the sharable `VAXCRTL' library.
Now this should work.
Even with this version, however, GNU CC itself should not be linked with
the sharable `VAXCRTL'. The version of qsort in
`VAXCRTL' has a bug (known to be present in VMS versions V4.6
through V5.5) which causes the compiler to fail.
The executables are generated by `make-cc1.com' and
`make-cccp.com' use the object library version of `VAXCRTL' in
order to make use of the qsort routine in `gcclib.olb'. If
you wish to link the compiler executables with the shareable image
version of `VAXCRTL', you should edit the file `tm.h' (created
by `vmsconfig.com') to define the macro QSORT_WORKAROUND.
QSORT_WORKAROUND is always defined when GNU CC is compiled with
VAX C, to avoid a problem in case `gcclib.olb' is not yet
available.