| Jean-Baptiste Queru | 4b29fe6 | 2009-11-12 18:46:23 -0800 | [diff] [blame^] | 1 | |
| 2 | Supported C language subset: |
| 3 | |
| 4 | - Expressions: |
| 5 | |
| 6 | * binary operators, by decreasing priority order: '*' '/' '%', |
| 7 | '+' '-', '>>' '<<', '<' '<=' '>' '>=', '==' '!=', '&', |
| 8 | '^', '|', '=', '&&', '||'. |
| 9 | |
| 10 | * '&&' and '||' have the same semantics as C : left to right |
| 11 | evaluation and early exit. |
| 12 | |
| 13 | * Parenthesis are supported. |
| 14 | |
| 15 | * Comma operator is supported. |
| 16 | |
| 17 | * Trinary operator (?:) is not supported. |
| 18 | |
| 19 | * Unary operators: '&', '*' (pointer indirection), '-' |
| 20 | (negation), '+', '!', '~', '++' and '--'. |
| 21 | |
| 22 | * Pointer indirection ('*') is supported. |
| 23 | |
| 24 | * Square brackets can be used for pointer arithmetic. |
| 25 | |
| 26 | * '=' and <op>= are supported. |
| 27 | |
| 28 | * Function calls are supported with standard Linux calling |
| 29 | convention. Function pointers are supported. |
| 30 | Functions can be used before being declared. |
| 31 | |
| 32 | - sizeof() is not supported. |
| 33 | |
| 34 | - Types: |
| 35 | + int, short, char, float, double |
| 36 | + pointers |
| 37 | + variables can be initialized in declarations. |
| 38 | + Only ANSI-style function declarations are supported. |
| 39 | - "..." is not supported. |
| 40 | - short is not supported |
| 41 | - const is not supported |
| 42 | - arrays are not supported |
| 43 | - long doubles are not supported |
| 44 | - structs are not supported |
| 45 | |
| 46 | - Unknown functions and variables are bound at compile time by calling |
| 47 | back to the caller. For the 'acc' command-line tool unknown functions |
| 48 | and variables are looked up using dlsym, to allow using many libc |
| 49 | functions and variables. |
| 50 | |
| 51 | - Instructions: blocks ('{' '}') are supported as in C. 'if' and |
| 52 | 'else' can be used for tests. The 'while' and 'for' C constructs |
| 53 | are supported for loops. 'break' can be used to exit |
| 54 | loops. 'return' is used for the return value of a function. |
| 55 | |
| 56 | - switch / case is not supported. |
| 57 | - goto and labels are not supported. |
| 58 | - continue is not supported. |
| 59 | |
| 60 | - Identifiers are parsed the same way as C. Local variables are |
| 61 | handled, but there is no local name space (not a problem if |
| 62 | different names are used for local and global variables). |
| 63 | |
| 64 | - Numbers can be entered in decimal, hexadecimal ('0x' or '0X' |
| 65 | prefix), or octal ('0' prefix). |
| 66 | |
| 67 | - Float and double constants are supported. |
| 68 | |
| 69 | - '#define' is supported without function like arguments. No macro |
| 70 | recursion is tolerated. Other preprocessor directives are |
| 71 | ignored. |
| 72 | |
| 73 | - C Strings and C character constants are supported. All ANSI C |
| 74 | character escapes are supported. |
| 75 | |
| 76 | - Both C comments ( /* */ ) and C++ comments ( // ... end-of-line ) are |
| 77 | supported. |
| 78 | |
| 79 | - Some syntax errors are reported, others may cause a crash. |
| 80 | |
| 81 | - Memory: the code, data, and symbol sizes are limited to 100KB |
| 82 | (it can be changed in the source code). |
| 83 | |