I want to get Free-CAD working on BeleniX and have been going through the dependencies. One of them is OpenCASCADE that I started to build one week back. Since then it has been a tale of pain till finally once week later I do have a successful build.

Firstly the software is enormous having thousands of files. For eg. after a make install I find that it installs 15600+ header files! I started building it with GCC4.4.1 on BeleniX. Secondly their document mentions support for building with Sun Forte Compiler on Solaris 8 – primitive info. Obviously the combination of OpenSolaris platform + Mesa + Gcc 4.4.1 is untested. Once I started I came across some usual issues: The configure script assumes Sun Studio/Forte and has options not supported by Gcc, some headers assumed Sun Studio/Forte, needed proper declaration for bcopy, replace usage of ieee_handler with fex_set_handling  etc. After those I started coming across variable names like SS, CS that conflict with predefined macros for x86 register names on OpenSolaris. I have seen this on many occassions in KDE and other software in places.

However after manually patching about 15 files from 15 build failures, I started to wonder how many more. So to test I ran a simple command: find . -type f | xargs grep -w SS. Believe it or not there were hundreds of matches! From a hunch I started a round-robin search with all the possible register names and for the record the following are used: CS, SS, DS, GS, FS, ES, ESP, EIP in about 465 different files. The only option now was to whip up a simple shell script to do a global search and replace. The resulting generated patchset is huge and I am not keeping it as a patch! I have embedded the script in the pkgbuild spec file.

At the end of this all I found that the Makefile does not have 100% DESTDIR support in spite of it using the GNU autotools. So I had to patch Makefile.in and that resulted in a full build. After packaging I discovered a packaging issue and had to re-run make install. Even though the source tree is already built that resulted in another full build! Looks like broken Makefiles.

After an exasperating several days I do have a package. I had faced this usage of common variable names clashing in the namespace in several different software like for eg. in Celestia 1.6 that I built last week. It uses the obvious “sun” to represent Sol. This is however a predefined macro in Gcc on OpenSolaris. Granted that this can be worked around by using “-Usun”(Unsafe ?) in CFLAGS and OpenSolaris exposing register defines in headers by default looks like a bug, it is nevertheless a really, REALLY BAD IDEA to use obvious, common, short variable names in your software.