| Supported C language subset (read joint example 'otccex.c' to have | |
| an introduction to OTCC dialect): | |
| - Expressions: | |
| * binary operators, by decreasing priority order: '*' '/' '%', | |
| '+' '-', '>>' '<<', '<' '<=' '>' '>=', '==' '!=', '&', | |
| '^', '|', '=', '&&', '||'. | |
| * '&&' and '||' have the same semantics as C : left to right | |
| evaluation and early exit. | |
| * Parenthesis are supported. | |
| * Unary operators: '&', '*' (pointer indirection), '-' | |
| (negation), '+', '!', '~', post fixed '++' and '--'. | |
| * Pointer indirection ('*') only works with explicit cast to | |
| 'char *', 'int *' or 'int (*)()' (function pointer). | |
| * '++', '--', and unary '&' can only be used with variable | |
| lvalue (left value). | |
| * '=' can only be used with variable or '*' (pointer | |
| indirection) lvalue. | |
| * Function calls are supported with standard i386 calling | |
| convention. Function pointers are supported with explicit | |
| cast. Functions can be used before being declared. | |
| - Types: only signed integer ('int') variables and functions can | |
| be declared. Variables cannot be initialized in | |
| declarations. Only old K&R function declarations are parsed | |
| (implicit integer return value and no types on arguments). | |
| - Any function or variable from the libc can be used because OTCC | |
| uses the libc dynamic linker to resolve undefined symbols. | |
| - Instructions: blocks ('{' '}') are supported as in C. 'if' and | |
| 'else' can be used for tests. The 'while' and 'for' C constructs | |
| are supported for loops. 'break' can be used to exit | |
| loops. 'return' is used for the return value of a function. | |
| - Identifiers are parsed the same way as C. Local variables are | |
| handled, but there is no local name space (not a problem if | |
| different names are used for local and global variables). | |
| - Numbers can be entered in decimal, hexadecimal ('0x' or '0X' | |
| prefix), or octal ('0' prefix). | |
| - '#define' is supported without function like arguments. No macro | |
| recursion is tolerated. Other preprocessor directives are | |
| ignored. | |
| - C Strings and C character constants are supported. Only '\n', | |
| '\"', '\'' and '\\' escapes are recognized. | |
| - Both C comments ( /* */ ) and C++ comments ( // ... end-of-line ) can be used. | |
| - No error is displayed if an incorrect program is given. | |
| - Memory: the code, data, and symbol sizes are limited to 100KB | |
| (it can be changed in the source code). | |