Building Jam 2.6 on OS/2 with OpenWatcom
These instructions pertain to ArcaOS 5.0.1 and OpenWatcom 1.9. Any other OS/2 versions and compilers may behave slightly differently; your mileage may wary.
Here we will go through the process of porting Perforce Jam 2.6, released in 2014. At the time of writing, the source can be downloaded from the Perforce website.
There is also FT Jam, from the FreeType project, which is quite possibly more advanced, even though it’s based on Perforce Jam 2.5. and hasn’t been updated since about 2006, apparently.
Haiku Jam is also worth checking out.
Copyright and disclaimers
Jam has the following copyright:
Copyright 1993-2002 Christopher Seiwald and Perforce Software, Inc.
License is hereby granted to use this software and distribute it freely, as long as this copyright notice is retained and modifications are clearly marked.
ALL WARRANTIES ARE HEREBY DISCLAIMED.
Furthermore, no work has been done to insure the OS/2 port is fit for any particular purpose, except to ensure it successfully builds itself.
The settings at the start should look like this.
CC = wcl386 CFLAGS = EXENAME = jam0.exe TARGET = -fe=$(EXENAME)
That is, the compiler is
wcl386, with no special C flags, and the name is
jam0.exe without the period and slash. The
wcl386 what to name the executable file; possible mnemonic: file executable.
wtouch all as the final command in the “all” rule, or build with
-c; otherwise WMake will complain the “all” target has not been built.
That takes care of the Makefile.
The make1.c file
There are minor changes in the make1.c file, because it unconditionally calls unlink() and we “fix that” with these macros at the start.
# ifdef OS_OS2 # define INCL_DOSFILEMGR # include <os2.h> # define unlink DosDelete # endif
You will need to remove the READ ONLY flag from the file before it
can be saved.
attrib -r make1.c
The execunix.c file
In this file, there are some major changes; so to speak.
At the top we add
# define INCL_DOSPROCESS # define INCL_DOSFILEMGR # include <os2.h> # define unlink DosDelete
inside the OS/2 section, because it also calls
unlink() unconditionally. And we also need to get access to process information, to get the PID.
The complete section shoudl look like this:
# ifdef OS_OS2 # define USE_EXECNT # include <process.h> # define INCL_DOSPROCESS # define INCL_DOSFILEMGR # include <os2.h> # define unlink DosDelete # endif
After this change, on line 188, is a
# ifdef USE_EXECNT
inside which is an NT call
GetCurrentProcessId() which we port to use
So at the start of the scope, we declare two new pointers, to the thread and process structure respectively.
TIB *thread; PIB *process;
And before sprintf() that refers to the PID, we call
DosGetInfoBlocks( &thread, &process );
while inside the
sprint() call itself, where GetCurrentProcessId() used to
be, we have
instead. The complete function call now looks like
sprintf( cmdtab[ slot ].tempfile, "%s\\jam%lut%d.bat", tempdir, process->pib_ulpid, slot );
where we have carefully updated the format specification to reflect unsigned long
%lu, instead of integer
%d. Even though integers and longs are the same size on 32bit OS/2, there’s no reason to be sloppy about format specifiers in the
printf() family of functions.
You will also need to remove the read only bit before saving the file.
attrib -r execunix.c
The jamgram.c and parse.c files
These source files will have some warning about undeclared function names. This is ok, and is not worth fixing just to get Jam working on OS/2. Maybe later, and particularly if Perforce is willing to accept contributions, it may turn out to be a worthwhile effort to fix.
This takes care of the source files.
wmake -u -c
in a command prompt, and Jam will bootstrap itself. The Jam built object files and executable will be in a subdirectory called
bin.os2x86 so don’t be surprised if you only see the
jam0.exe file at first.
On modern hardware, the complete build takes only a few seconds.
-u is for unix compatibility mode, and allows WMake to understand the backslash line continuation syntax; lines that end with
\ are joined. Without this, there will be an error.
As mentioned previously, the
-c is to stop WMake from complaining that “all” has not been built. Leave it out of you added
wtouch all to the rule.
To install Jam, just copy the
jam.exe file into
c:\usr\local\bin, which you may have to create first, or wherever your
copy bin.os2x86\jam.exe c:\usr\local\bin\
It is normal that the
mkdir commands fail when the directory exists already.
Alternatively, you can write the commands like this, in case your
UNIXROOT is not
copy bin.os2x86\jam.exe %UNIXROOT%\usr\local\bin
Congratulations, now you have completed the build and installation of Perforce Jam 2.6.
Do you need professional assistance with OS/2? Write to firstname.lastname@example.org.
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