Difference between revisions of "Code Generation/Example 2"

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< Code Generation
(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...)
 
(Postfix Code)
 
(18 intermediate revisions by the same user not shown)
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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 17:56, 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