| Frabrice Bellard | a969305 | 2009-05-11 14:50:37 -0700 | [diff] [blame] | 1 | |
| 2 | Supported C language subset (read joint example 'otccex.c' to have |
| 3 | an introduction to OTCC dialect): |
| 4 | |
| 5 | - Expressions: |
| 6 | |
| 7 | * binary operators, by decreasing priority order: '*' '/' '%', |
| 8 | '+' '-', '>>' '<<', '<' '<=' '>' '>=', '==' '!=', '&', |
| 9 | '^', '|', '=', '&&', '||'. |
| 10 | |
| 11 | * '&&' and '||' have the same semantics as C : left to right |
| 12 | evaluation and early exit. |
| 13 | |
| 14 | * Parenthesis are supported. |
| 15 | |
| 16 | * Unary operators: '&', '*' (pointer indirection), '-' |
| 17 | (negation), '+', '!', '~', post fixed '++' and '--'. |
| 18 | |
| 19 | * Pointer indirection ('*') only works with explicit cast to |
| 20 | 'char *', 'int *' or 'int (*)()' (function pointer). |
| 21 | |
| 22 | * '++', '--', and unary '&' can only be used with variable |
| 23 | lvalue (left value). |
| 24 | |
| 25 | * '=' can only be used with variable or '*' (pointer |
| 26 | indirection) lvalue. |
| 27 | |
| 28 | * Function calls are supported with standard i386 calling |
| 29 | convention. Function pointers are supported with explicit |
| 30 | cast. Functions can be used before being declared. |
| 31 | |
| 32 | - Types: only signed integer ('int') variables and functions can |
| 33 | be declared. Variables cannot be initialized in |
| 34 | declarations. Only old K&R function declarations are parsed |
| 35 | (implicit integer return value and no types on arguments). |
| 36 | |
| 37 | - Any function or variable from the libc can be used because OTCC |
| 38 | uses the libc dynamic linker to resolve undefined symbols. |
| 39 | |
| 40 | - Instructions: blocks ('{' '}') are supported as in C. 'if' and |
| 41 | 'else' can be used for tests. The 'while' and 'for' C constructs |
| 42 | are supported for loops. 'break' can be used to exit |
| 43 | loops. 'return' is used for the return value of a function. |
| 44 | |
| 45 | - Identifiers are parsed the same way as C. Local variables are |
| 46 | handled, but there is no local name space (not a problem if |
| 47 | different names are used for local and global variables). |
| 48 | |
| 49 | - Numbers can be entered in decimal, hexadecimal ('0x' or '0X' |
| 50 | prefix), or octal ('0' prefix). |
| 51 | |
| 52 | - '#define' is supported without function like arguments. No macro |
| 53 | recursion is tolerated. Other preprocessor directives are |
| 54 | ignored. |
| 55 | |
| 56 | - C Strings and C character constants are supported. Only '\n', |
| 57 | '\"', '\'' and '\\' escapes are recognized. |
| 58 | |
| Jack Palevich | 9918d0a | 2009-05-15 10:57:02 -0700 | [diff] [blame] | 59 | - Both C comments ( /* */ ) and C++ comments ( // ... end-of-line ) can be used. |
| Frabrice Bellard | a969305 | 2009-05-11 14:50:37 -0700 | [diff] [blame] | 60 | |
| 61 | - No error is displayed if an incorrect program is given. |
| 62 | |
| 63 | - Memory: the code, data, and symbol sizes are limited to 100KB |
| 64 | (it can be changed in the source code). |
| 65 | |