Obfuscated Tiny C Compiler review

Obfuscated Tiny C Compiler (OTCC) is a very small C compiler I wrote in order to win the International Obfuscated C Code Contest (IOC

License: GPL (GNU General Public License) File size: 3K Developer: Fabrice Bellard

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Obfuscated Tiny C Compiler (OTCC) is a very small C compiler I wrote in order to win the International Obfuscated C Code Contest (IOCCC) in 2002.

My goal was to write the smallest C compiler which is able to compile itself. I choose a subset of C which was general enough to write a small C compiler. Then I extended the C subset until I reached the maximum size authorized by the contest: 2048 bytes of C source excluding the ';', '{', '}' and space characters.

I choose to generate i386 code. The original OTCC code could only run on i386 Linux because it relied on endianness and unaligned access. It generated the program in memory and launched it directly. External symbols were resolved with dlsym().

In order to have a portable version of OTCC, I made a variant called OTCCELF. It is only a little larger than OTCC, but it generates directly a dynamically linked i386 ELF executable from a C source without relying on any binutils tools! OTCCELF was tested succesfully on i386 Linux and on Sparc Solaris.

NOTE: My other project TinyCC which is a fully featured ISOC99 C compiler was written by starting from the source code of OTCC !

Compilation:

gcc -O2 otcc.c -o otcc -ldl
gcc -O2 otccelf.c -o otccelf

Self-compilation:

./otccelf otccelf.c otccelf1