Code Generation/Example 2: Difference between revisions

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New page: == The Original Code == Consider the following S9 function: <c> string a = "ola"; int s9() -> 0 { a! } </c> == Postfix Code == The Postfix code for the above func...
 
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== The Original Code ==
== The Original Code ==


Consider the following [[S9 Language|S9]] function:
Consider the following C function:


<c>
<source lang="c">
string a = "ola";
const char *a = "batata";
int s9() -> 0 {
int main() {
      a!
  prints(a);
  return 0;
}
}
</c>
</source>


== Postfix Code ==
== Postfix Code ==


The Postfix code for the above function is as follows:  
The Postfix code for the above function is as follows:  
 
{{CollapsedCode|Postfix code|
<asm>
<source lang="asm">
;--- declaring the string literal
;--- declaring the string literal
RODATA
RODATA
ALIGN
ALIGN
LABEL zum ;; deveria ser automático
LABEL _L123 ;; automatic label
STR "ola"
SSTRING "batata"
;--- declaring the global variable "a"
;--- declaring the global variable "a"
DATA
DATA
ALIGN
ALIGN
GLOBAL a, OBJ
LABEL a
LABEL a
ID zum ;; deveria ser automático
SADDR  _L123 ;; automatic label


;--- this is the main function (note that "s9" translates to RTS's "_main")
;--- this is the main function (note that "s9" translates to RTS's "_main")
TEXT
TEXT
ALIGN
ALIGN
GLOBL _main, FUNC
GLOBAL _main, FUNC
LABEL _main
LABEL _main
ENTER 0
ENTER 0
ADDRV a
 
EXTRN prints
ADDR a
LDINT
EXTERN prints
CALL prints
CALL prints
TRASH 4
TRASH 4
INT 0
INT 0
POP
STFVAL32
LEAVE
LEAVE
RET
RET
</asm>
</source>
}}
 
== Compiling and Running ==
<!--
To test the first example, the S9 compilation process is as follows:
 
s9 batata.s9
yasm -felf batata.asm
ld -o batata batata.o -lrts
-->
To test the second program directly, [[Compiladores/Projecto de Compiladores/Compiladores Exemplo|pf2asm]] can be used:
 
pf2asm batata.pf
yasm -felf batata.asm
ld -o batata batata.o -lrts


[[category:Compilers]]
[[category:Compiladores]]
[[category:Teaching]]
[[category:Ensino]]

Latest revision as of 15:56, 6 May 2020

The Original Code

Consider the following C function:

const char *a = "batata";
int main() {
  prints(a);
  return 0;
}

Postfix Code

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

Compiling and Running

To test the second program directly, pf2asm can be used:

pf2asm batata.pf
yasm -felf batata.asm
ld -o batata batata.o -lrts