====== Selected Phases of a Compiler ======


++++source code|
<code>
  int i = 0; /* some comment */
  int j = 0;
  while (i < 10) {
    System.out.println(j);
    i = i + 1;
    j = j + 2*i+1;
  }
</code>
++++

^ [[Lecture 01|Lexer]] ^

++++list of tokens|
  INT, Identifier("i"), EQUAL, IntNumeral(0), SEMICOLON, INT, Identifier("j"), EQUAL, ...
  WHILE, OPENPAREN, Identifier("i"), LESSTHAN, IntNumeral(10), CLOSEDPAREN, OPENBRACE,
  Identifier("System"), DOT, Identifier("out"), ...

++++

^ [[Lecture 03|Parser]] ^

++++concrete syntax tree|
  Declaration(INT, Identifier("i"), EQUAL, InitialExpression(IntConst(IntNumeral(0)),
    Declaration(INT, Identifier("j"), EQUAL, InitialExpression(IntConst(IntNumeral(0)),
      WhileStatememt(WHILE, OPENPAREN, LessThanExpr(Identifier("i"),LESSTHAN,IntNumeral(10)),
                            CLOSEDPAREN,
        StatementBlock(OPENBRACE,
          Statement(MethodCall(DotExpr(Identifier("System"),DOT,Identifier("out")),DOT,
                     Identifier("println"),
                     OPENPAREN,ArgumentList(Identifier("j")),CLOSEDPAREN),
          SEMICOLON,
            ...
        )
       )
     )
  )
++++

^ [[Lecture 04|Abstract Syntax Tree Construction]] ^

++++abstract syntax tree|
  Declaration("i",IntType,Some(IntConst(0)),
    Declaration("j",IntType,Some(IntConst(0)),
      WhileStatememt(LessThan(Ident("i"),IntConst(10)),
        StatementBlock(
          MethodCall(DotExpr(Ident("System"),"out"),
                     "println",
                     List(Ident("j"))),
          Assignment("i", Plus(Ident("i"),IntConst(1))),
          Assignment("j", Plus(Ident("j"),
                               Times(IntConst(2),Ident("i"),
                               IntConst(1))
        )
       )
     )
  )
++++

^ [[Lecture 06|Semantic Analysis and Type Checking]] ^

++++resolved tree and symbol table|
  Declaration("i",IntType,Some(IntConst(0)),
    Declaration("j",IntType,Some(IntConst(0)),
      WhileStatememt(LessThan(Ident("i"),IntConst(10)),
        StatementBlock(
          MethodCall(DotExpr(Ident("System"),"out"),
                     "println",
                     List(Ident("j"))),
          Assignment("i", TYPE(Plus(TYPE(Ident("i"),INT),IntConst(1))),INT),
          Assignment("j", TYPE(Plus(TYPE(Ident("j"),INT),
                               TYPE(Times(IntConst(2),TYPE(Ident("i"),INT),INT),
                               TYPE(IntConst(1),INT)),INT)
        )
       )
     )
  )

  i -> (LocalVar,INT)
  j -> (LocalVar,INT)

++++

^ [[Intermediate Code Generation]] ^

++++source- and taget-independent format|

control-flow graph containing three-address code instructions

----

{{cc09:cfg.png|CFG?640}}

----

++++

^ [[Lecture 08|Target Code Generation]] ^

++++translated program|
[[test.jvm]]
++++