Tiger 2002

This is not standard C++

We used to run the standard compiler from NetBSD: egcs 1.1.2. This was not standard C++ (e.g., we used to include <iostream.h>}, we could use members of the std name space unqualified etc.). In addition, we were using hash_map which is an SGI extension that is not available in standard C++. It was therefore decided to upgrade the compiler in 2003, and to upgrade the programming style.

Wrapping a tarball is impossible

During the first edition of the Tiger Compiler project, students had to write their own Makefiles—after all, knowing Make is considered mandatory for an Epitean. This had the most dramatic effects, with a wide range of creative and imaginative ways to have your project fail; for instance:

Forget to ship some files

Ship object files, or even the executable itself. Needless to say that NetBSD executables did not run properly on Akim’s gnu/Linux box.

Ship temporary files (*~, #*#, etc.).

Ship core dumps (“Wow! This is the heck of an heavy tarball…’’).

Ship tarballs in the tarball.

Ship tarballs of other groups in the tarball. It was then hard to demonstrate they were not cheating :)

Have incorrect dependencies that cause magic failures.

Have completely lost confidence in dependencies and Make, and therefore define the all target as first running clean and then the actual build.

As a result Akim grew tired of fixing the tarballs, and in order to have a robust, efficient (albeit some piece of pain in the neck sometimes) distribution 1 we moved to using Automake, and hence Autoconf.

There are reasons not to be happy with it, agreed. But there are many more reasons to be sad without it. So Autoconf and Automake are here to stay.

Note, however, that you are free to use another system if you wish. Just obey the standard package interface (Submission).

The SemantVisitor is a nightmare to maintain

The SemantVisitor, which performs both the type checking and the translation to intermediate code, was near to impossible to deliver in pieces to the students: because type checking and translation were so much intertwined, it was not possible to deliver as a first step the type checking machinery template, and then the translation pieces. Students had to fight with non applicable patches. This was fixed in Tiger 2003 by splitting the SemantVisitor into TypeVisitor and TranslationVisitor. The negative impact, of course, is a performance loss.

Akim is tired during the student defenses

Seeing every single group for each compiler stage is a nightmare. Sometimes Akim was not enough aware.

Footnotes

1

See the shift of language? From tarball to distribution.