diff options
Diffstat (limited to 'runtime/vmop.h')
| -rw-r--r-- | runtime/vmop.h | 33 |
1 files changed, 30 insertions, 3 deletions
diff --git a/runtime/vmop.h b/runtime/vmop.h index c3d5d5f4..938b08fd 100644 --- a/runtime/vmop.h +++ b/runtime/vmop.h @@ -59,17 +59,44 @@ typedef enum { /* do NOT start at 0 to detect uninitialized types after calloc( opcode_PUSHMSGVAR = 1002, /* requires var operand */ opcode_PUSHCONSTANT = 1003, /* requires var operand */ opcode_UNARY_MINUS = 1010, - opcode_END_PROG = 1011 + opcode_FUNC_CALL = 1012, + opcode_END_PROG = 2000 } opcode_t; +/* Additional doc, operation specific + + FUNC_CALL + All parameter passing is via the stack. Parameters are placed onto the stack in reverse order, + that means the last parameter is on top of the stack, the first at the bottom location. + At the actual top of the stack is the number of parameters. This permits functions to be + called with variable number of arguments. The function itself is responsible for poping + the right number of parameters of the stack and complaining if the number is incorrect. + On exit, a single return value must be pushed onto the stack. The FUNC_CALL operation + is generic. Its pVar argument contains the function name string (TODO: very slow, make + faster in later releases). + + Sample Function call: sampleFunc(p1, p2, p3) ; returns number 4711 (sample) + Stacklayout on entry (order is top to bottom): + 3 + p3 + p2 + p1 + ... other vars ... + + Stack on exit + 4711 + ... other vars ... + + */ + + /* the vmop object */ typedef struct vmop_s { BEGINobjInstance; /* Data to implement generic object - MUST be the first data element! */ opcode_t opcode; union { - var_t *pVar; - /* TODO: add function pointer */ + var_t *pVar; /* for function call, this is the name (string) of function to be called */ } operand; struct vmop_s *pNext; /* next operation or NULL, if end of program (logically this belongs to vmprg) */ } vmop_t; |