컴파일러

어휘 해석(Lexical Analysis)

스캔

어휘 해석기(LEXICAL ANALYZER) 또는 스캐너

토큰열을 생성

스캐너 제너레이터

구문 해석(Syntax Analysis)

parse

추상 구문 트리

파서 제너레이터

의미 해석(Semantic Analysis)

중간 코드

(operation ,left operand,right operand,result,<Cmp>,Lbl))

<Cmp>

1(==)
2(<)
3(>)
4(<=)
5(>=)
6(!=)

(MOV, A,,B)
(ADD, A,B,C)
(NEG, A,,B)
(JMP, ,,,,Lbl)
(TST, A,B,,<Cmp>,Lbl)

Label

run-time operations

Code Generation

(MOV, A,,B)
==>
LOD R1,A
STO R1,B

(ADD, A,B,T1)
==>
LOD R1,A
ADD R1,B
STO R1,T1

(JMP, ,,,,Lbl)
==>
CMP 0,0,0
JMP Lbl

(TST, A,B,,<Cmp>,Lbl)
==>
LOD R1,A
CMP R1,B,<Cmp>
JMP Lbl

Label

(LBL, ,,,,Lbl)

Unconditional Jump

(JMP, ,,,,Lbl)

Conditional Branch

(TST, E1,E2,,<Cmp>,Lbl)

A '+' B '*' C '+' D
==>

(MULT B,C,Temp1)
(MULT A,Temp1,Temp2)
(ADD Temp2,D,Temp3)

a '=' b '+' '(' c '=' 3 ')'

==>
(MOV, 3,,c)
(ADD, b,c,T1)
(MOV, T1,,a)

x '>' y

==>
(MOV, 1,,T1)
(TST, x,y,,3,L1)
(MOV, 0,,T1)
(LBL, L1)

if '(' Expr ')' Stmt1 (else Stmt2)

==>
Expr

(TST, t0,0,,1,Lbl1)
Stmt1
(JMP, ,,,,Lbl2)
(Lbl, ,,,,Lbl1)
Stmt2
(Lbl, ,,,,Lbl2)

If (A>B) A = B * C
==>

(MOV, 1,,T1)

LOD R1,='1'
STO R1,T1

(TST, A,B,,3.L1)

LOD R1,A
CMP R1,B,3
JMP L1

(MOV 0,,T1)

LOD R1,='0'
STO R1,T1

(LBL, L1)
    L1:
(TST, T1,0,1,L2)

LOD R1,T1
CMP R1,='0',1
JMP L2

(MUL, B,C,A)

LOD R1,B
MUL R1,C
STO R1,A

(JMP, L3)

CMP 0,0,0
JMP L3

(LBL, L2)
    L2:
(LBL, L3)
    L3:

while '(' Expr')' Stmt

==>
(Lbl, ,,,,Lbl1)

Expr

(TST, t0,0,,6,Lbl2)
Stmt
(JMP, ,,,,Lbl1)
(Lbl, ,,,,Lbl2)

for '(' Expr1 ';' Expr2 ';' Expr3) Stmt
/*
Expr1;
while (Expr2)
{   Stmt
    Expr3;
}
*/

==>
Expr1
(Lbl, ,,,,Lbl1)
Expr2
(TST, t1,0,,1,Lbl2)
(JMP, ,,,,Lbl3)
(Lbl, ,,,,Lbl4)

Expr3
(JMP, ,,,,Lbl1)
(Lbl, ,,,,Lbl4)
Stmt
(JMP, ,,,,Lbl4)
(Lbl, ,,,,Lbl3)

gcc

cpp

전처리기(preprocessor)

cc1

어셈블러 코드가 생성된다

collect2(as)

object 파일이 생성된다

참조 사이트:

http://elvis.rowan.edu/~bergmann/books.html