Dmake

Notes on the port of dmake to OS/2 ================================== Jon Saxton March 2004 Dmake is a make utility on steroids. It is extremely powerful and highly configurable. It has been ported to many operating systems. It is capable of using multiple computers on a network to build complex projects. I am a long-time user of dmake but I am not an expert. I have not used anything approaching all of its features. When I need to do something a bit beyond the mundane, I consult the (somewhat outdated but still accurate) manual. My main reason for using dmake rather than some other comparable tool is historical. I had tried dmake some years ago and so I was somewhat familiar with it. Then about four years ago I started writing C and C++ programs for UNIX. As far as possible I do all the development and testing on OS/2. Once I am satisfied that the program is working, I squirt the source code over the wire to a UNIX system for compiling and linking. I maintain exactly one set of source files for each project and I do not want to maintain two distinct makefiles. By writing my makefiles for processing by dmake, it is possible for me to have one makefile which works unchanged on OS/2 and UNIX. There are probably other tools which would work just as well (gnu make is one that springs to mind), but I have not investigated those. Quite recently I needed to have one of my OS/2-UNIX programs execute on Windows 2000. I found a compiled version of dmake on the internet and it worked perfectly for that project but it turned out to be a slightly more recent version than the one I had been using on OS/2 and UNIX so I decided to update my version. For some time now the official dmake web site (http://dmake.wticorp.com) seems to have been inaccessible. Meanwhile dmake is used by the Open Office team as its build tool and the dmake source code is part of the Open Office distribution. That is what I used for this exercise. I fixed a few minor spelling errors: openning -> opening infering -> inferring and changed all the grave accents used as quote marks to apostrophes ` -> ' for no reason other than that to me the pairing of the grave accent with the apostrophe is `really' ugly on every display that I have used. I constructed the OS/2-gcc version of config.h by hand and modified the OS/2 version of switchar.c to return '-' as the switch character instead of '/'. This has the side-effect of causing the directory separator to be reported as '/' instead of '\'. There are very few circumstances in which this matters and using '/' on all platforms has the benefit of consistency. However it is not necessary for portable makefiles because the configuration files supplied with dmake define the macro $/ to be the directory separator character. Using $/ in place of / would insert the correct separator in any environment so I could have left switchar.c alone. There were other places where \ needed to be changed to / but as I write I can only remember one, namely slash.h. The changes I made to the primary dmake sources were pretty trivial but I did make build a new "gcc" directory underneath "os2". That directory contains a tempnam.c file like the pre-existing ones in the "icc" heirarchy but it is not used. The gcc/emx build uses the one in os2. As I said above, the manual (man/dmake.nc) is somewhat outdated. The current version of dmake supports a small range of logical and arithmetic operators. For example, one can say .IF $(COLOUR) == yellow .IF $(COLOUR) != yellow .IF $(ANSWER) >= 42 .IF $(COLOUR) == yellow || $(ANSWER) == 42 The comparison operators are: == equal != not equal > greater < less >= greater or equal <= less or equal and the logical operators are: && and || or I haven't yet figured out the precedence of the logical operators yet but they are both of lower precedence than the comparison operators. When dmake starts up, it needs to find its configuration file. For OS/2 the program looks for "startup.mk" in a directory described by the environ- ment variable DMAKEROOT. Thus if you have in config.sys or the startup script for your text session set dmakeroot=d:/u/etc/dmake then dmake will look for d:/u/etc/dmake/startup.mk. This is established by a line in startup.h which gets included in ruletab.c. The configuration file can be specified more directly by setting another environment variable, namely "makestartup". For example, set makestartup=d:/u/etc/dmake/startup.mk will have exactly the same effect as the dmakeroot setting shown earlier. I have included a sample set of run-time configuration files. These start with "startup.mk" which ultimately includes all the others that are appropriate for the extant build environment. I have added extensive notes to startup.mk and less extensive notes to the others. ============ Windows 2000 ============= While I was at it, I built a new version of dmake for Windows (NT/2000). I tried running the configure script under mingw but it failed and since I was in no mood to debug the script so I just made a selective copy of the files in the os2 subdirectory into the winnt subdirectory and tweaked them ever so slightly to make the initial compile work. From a gcc text session type make.cmd winnt-gcc to build the Windows version. I opened an msys window then ran cmd.exe on top to get the correct environment. All the notes for OS/2 apply equally to Windows.