(→The Original Code) |
(→Postfix Code) |
||
| (One intermediate revision by the same user not shown) | |||
| Line 20: | Line 20: | ||
ALIGN | ALIGN | ||
LABEL _L123 ;; automatic label | LABEL _L123 ;; automatic label | ||
| − | + | SSTRING "batata" | |
;--- declaring the global variable "a" | ;--- declaring the global variable "a" | ||
DATA | DATA | ||
ALIGN | ALIGN | ||
| + | GLOBAL a, OBJ | ||
LABEL a | LABEL a | ||
SADDR _L123 ;; automatic label | SADDR _L123 ;; automatic label | ||
| Line 30: | Line 31: | ||
TEXT | TEXT | ||
ALIGN | ALIGN | ||
| − | + | GLOBAL _main, FUNC | |
LABEL _main | LABEL _main | ||
ENTER 0 | ENTER 0 | ||
| Line 36: | Line 37: | ||
ADDR a | ADDR a | ||
LDINT | LDINT | ||
| − | + | EXTERN prints | |
CALL prints | CALL prints | ||
TRASH 4 | TRASH 4 | ||
Consider the following C function:
const char *a = "batata";
int main() {
prints(a);
return 0;
}
The Postfix code for the above function is as follows:
| Postfix code |
|---|
;--- declaring the string literal
RODATA
ALIGN
LABEL _L123 ;; automatic label
SSTRING "batata"
;--- declaring the global variable "a"
DATA
ALIGN
GLOBAL a, OBJ
LABEL a
SADDR _L123 ;; automatic label
;--- this is the main function (note that "s9" translates to RTS's "_main")
TEXT
ALIGN
GLOBAL _main, FUNC
LABEL _main
ENTER 0
ADDR a
LDINT
EXTERN prints
CALL prints
TRASH 4
INT 0
STFVAL32
LEAVE
RET
|
To test the second program directly, pf2asm can be used:
pf2asm batata.pf yasm -felf batata.asm ld -o batata batata.o -lrts