パターンマッチの作り方(5) 構造体初期化構文糖

構造体の初期化を纏めて出来るシンタックスシュガーを追加します。
この機能は、パターンマッチのヴァリアントを初期化する際に必要なのでここで作成します。

## 実装


型の宣言

```scala:
case class ETuple(t:T,ls:List[E]) extends E
```

テストの追加

初期化の値はETupleで初期化します。

```scala:
        // 構造体初期化リテラル
        EVal(TStr(List(("a", Ti(32)), ("b", Ti(32)))), "ab",
          ETuple(TStr(List(("a", Ti(32)), ("b", Ti(32)))),
            List(ELdc(Ti(32),123),ELdc(Ti(32),456)))),
        EPrint(Ti(32), EField(Ti(32), "ab", "a")),
        EPrint(Ti(32), EField(Ti(32), "ab", "b"))
```

kNormalのEValの修正

```scala:
      case EVal(t:TStr, id, null) =>
        emit.llstruct(t)
        env.add(RL(t,id))
        add(LLAlloca(RL(t,id)))
        RL(t,id)
```

EValの箇所に追加

```scala:
      case EVal(t: TStr, id, tpl) =>
        emit.llstruct(t)
        env.add(RL(t,id))
        add(LLAlloca(RL(t,id)))
        tpl match {
          case ETuple(_, ls) =>
            for ((e, (name, t)) <- ls.zip(t.types)) {
              f(EAssign(t, EField(t, id, name), e))
            }
          case null =>
          case _ => throw new Exception("error")
        }
        RL(t,id)
```

以上！簡単。


```scala
package chapter05

import java.io._

sealed trait E {
  def t:T
}
case class ELdc(t:T, i:Long) extends E
case class EBin(t:T, s:String, l:E, r:E) extends E
case class EPrint(t:T, a:E) extends E
case class EBlock(t: T, ls: List[E]) extends E
case class EVal(t: T, id: String, a: E) extends E
case class EId(t: T, id: String) extends E
case class EAssign(t: T, a: E, b: E) extends E
case class EField(t: T, id: String, idx: String) extends E
case class ETuple(t:T,ls:List[E]) extends E

sealed trait T
case class Ti(i:Int) extends T
case object Tv extends T
case class TFun(t: T, prms: List[T]) extends T
case class TStr(types: List[(String, T)]) extends T

object T {
  def find(t:TStr, a: String): (Int, T) = {
    def f(i: Int, xs: List[(String, T)]): (Int, T) = {
      xs match {
        case List() => (-1, Tv)
        case (x, t) :: xs => if (a == x) (i, t) else f(i + 1, xs)
      }
    }
    f(0, t.types)
  }
}

case class Op(s: String) {
  def apply(t: T, a: E, b: E): E = {
    EBin(t, s, a, b)
  }
}
object EAdd extends Op("add")
object EMul extends Op("mul")

sealed trait R {
  def t:T
  def id:String
}
case class RG(t:T, id: String) extends R
case class RL(t:T, id: String) extends R
case class RR(t:T, id: String) extends R
case class RN(t:T, id: String) extends R

object test {
  def main(argv: Array[String]) {
    try {
      val ast = EBlock(Tv, List(
        EPrint(Ti(32), ELdc(Ti(32), 11)),
        EPrint(Ti(32), EAdd(Ti(32), ELdc(Ti(32), 11), ELdc(Ti(32), 22))),
        // 変数 a 定数
        EVal(Ti(32), "a", ELdc(Ti(32), 11)),
        EPrint(Ti(32), EId(Ti(32), "a")),
        // 変数 b 足し算
        EVal(Ti(32), "b", EAdd(Ti(32), ELdc(Ti(32), 11), ELdc(Ti(32), 22))),
        EPrint(Ti(32), EId(Ti(32), "b")),
        // 変数 c 変数の値
        EVal(Ti(32), "c", EId(Ti(32), "a")),
        EPrint(Ti(32), EId(Ti(32), "c")),
        // 構造体
        EVal(TStr(List(("a", Ti(32)), ("b", Ti(32)))), "aa", null),
        EAssign(Ti(32), EField(Ti(32), "aa", "a"), ELdc(Ti(32), 9)),
        EAssign(Ti(32), EField(Ti(32), "aa", "b"), EId(Ti(32), "c")),
        EPrint(Ti(32), EField(Ti(32), "aa", "a")),
        EPrint(Ti(32), EField(Ti(32), "aa", "b")),
        // 構造体初期化リテラル
        EVal(TStr(List(("a", Ti(32)), ("b", Ti(32)))), "ab",
          ETuple(TStr(List(("a", Ti(32)), ("b", Ti(32)))),
            List(ELdc(Ti(32),123),ELdc(Ti(32),456)))),
        EPrint(Ti(32), EField(Ti(32), "ab", "a")),
        EPrint(Ti(32), EField(Ti(32), "ab", "b"))
      ))
      println("ast=" + ast)
      val ll = kNormal(ast)
      println("ll=" + ll)
      val ll2 = constFold(ll)
      emit("e.ll", ll2)
      println(exec("llc e.ll -o e.s"))
      println(exec("llvm-gcc -m64 e.s -o e"))
      println(exec("./e"))
    } catch {
      case e:Throwable => e.printStackTrace()
    }
  }
}

object kNormal {
  def gid(t:T): R = {
    RR(t,genid(""))
  }
  var ls: List[LL] = null
  def add(l: LL) {
    ls = l :: ls
  }

  def arr(e: E): R = {
    e match {
      case EField(t, id, idx) =>
        env.map(id) match {
          case i:R =>
            println("i="+i + " id="+id)
            val ((n, nt), reg1) = (T.find(i.t.asInstanceOf[TStr],idx), gid(t))
            add(LLField(reg1, i, RN(Ti(64),"0"), RN(nt,""+n)))
            reg1
          case t => throw new Exception("type mismatch " + t)
        }
      case EId(t, id) => env.map(id)
      case _ => throw new Exception("error")
    }
  }
  
  def f(a: E): R = {
    a match {
      case EBin(t, op, a1, b1) =>
        (f(a1), f(b1), gid(t)) match {
          case (a, b, id) =>
            if (t != a.t || t != b.t) throw new Exception("type mismatch " + t)
            add(LLBin(id, op, a, b))
            id
        }
      case ELdc(t, i) => RN(t, ""+i)
      case EPrint(t, a) =>
        f(a) match {
          case a =>
            if (t != a.t) throw new Exception("type mismatch t=" + t + " ta=" + a.t)
            add(LLCall(null, RG(TFun(Tv, List(t)), "print_" + emit.llt(t)), List((a.t, a))))
            a
        }
      case EBlock(t, ls) =>
        ls.foldLeft(null: R) {
          case (tid, l) => f(l)
        }
      case EVal(t: TStr, id, tpl) =>
        emit.llstruct(t)
        env.add(RL(t,id))
        add(LLAlloca(RL(t,id)))
        tpl match {
          case ETuple(_, ls) =>
            for ((e, (name, t)) <- ls.zip(t.types)) {
              f(EAssign(t, EField(t, id, name), e))
            }
          case null =>
          case _ => throw new Exception("error")
        }
        RL(t,id)
      case e @ EVal(t, id, a) =>
        f(a) match {
          case a =>
            env.add(RL(t, id))
            add(LLAssign(RL(a.t, id), a))
            RL(a.t, id)
        }
      case EId(t, id) => env.map(id)
      case EAssign(t, a, b) =>
        (arr(a), f(b)) match {
          case (a, b) =>
            if (t != b.t) throw new Exception("type mismatch " + t + " " + b.t)
            add(LLStore(b, a))
            b
        }
      case a: EField =>
        val a2 = arr(a)
        val b = gid(a2.t)
        add(LLLoad(b, a2))
        b
    }
  }

  def apply(a: E): List[LL] = {
    ls = List[LL]()
    f(a)
    ls.reverse
  }
}

object env {
  var map = Map[String, R]()
  def add(r: R) {
    map = map + (r.id -> r)
  }
}

sealed trait LL
case class LLCall(id: R, op: R, prms: List[(T, R)]) extends LL
case class LLBin(id: R, op: String, a: R, b: R) extends LL
case class LLAssign(s: R, d: R) extends LL
case class LLField(id1: R, aid: R, z: R, b: R) extends LL
case class LLAlloca(id: R) extends LL
case class LLLoad(id1: R, id2: R) extends LL
case class LLStore(id1: R, id2: R) extends LL

object constFold {
  var map: Map[R, R] = null
  def m(v: R): R = {
    if (map.contains(v)) m(map(v)) else v
  }
  def fs(prms: List[(T, R)]): List[(T, R)] = {
    prms.map {
      case (t, v) => (t, m(v))
    }
  }
  def apply(ls: List[LL]): List[LL] = {
    map = Map()
    ls.foldLeft(List[LL]()) {
      case (ls, l @ LLCall(id, op, prms)) => l.copy(prms = fs(prms)) :: ls
      case (ls, l @ LLBin(id, op, a, b)) => l.copy(a = m(a), b = m(b)) :: ls
      case (ls, l @ LLAssign(s, d)) => map = map + (s -> d); ls
      case (ls, l @ LLAlloca(id: R)) => l.copy(m(id)) :: ls
      case (ls, l @ LLField(id, id2, id3, id4)) => l.copy(id, m(id2), m(id3), m(id4)) :: ls
      case (ls, l @ LLStore(id1, id2)) => l.copy(m(id1), m(id2)) :: ls
      case (ls, l @ LLLoad(id1, id2)) => l.copy(m(id1), m(id2)) :: ls
      case (ls, l) => throw new Exception("error no implementation "+l)
    }.reverse
  }
}

object emit {

  def llt(t:T):String = {
    t match {
      case Ti(i) => "i" + i
      case Tv => "void"
      case TFun(t, ls) => llt(t) + "(" + ls.map(llt).mkString(", ") + ")*"
      case t:TStr => llstruct(t)
    }
  }

  def llr(r:R): String = {
    r match {
      case RG(t,id) => "@" + id
      case RL(t,id) => "%" + id
      case RR(t,id) => "%." + id
      case RN(t,id) => "" + id
    }
  }
  
  def o(id: R, out: String) {
    if (id != null) asm(llr(id) + " = " + out)
    else asm(out)
  }
  def f(l: LL) {
    l match {
      case LLCall(id, op, prms) =>
        val ps = prms.map { case (a, b) => llt(a) + " " + llr(b) }.mkString(", ")
        o(id, "call " + llt(op.t) + " " + llr(op) + "(" + ps + ") nounwind")
      case LLBin(id, op, a, b) =>
        o(id, op + " " + llt(id.t) + " " + llr(a) + ", " + llr(b))
      case _:LLAssign => throw new Exception("error")
      case LLField(reg1: R, addr: R, zero: R, a: R) =>
        o(reg1, "getelementptr inbounds " + llt(addr.t) + "* " + llr(addr) + ", " + llt(zero.t) + " " + llr(zero) + ", " + llt(a.t) + " " + llr(a))
      case LLLoad(reg1: R, reg2: R) =>
        o(reg1, "load " + llt(reg1.t) + "* " + llr(reg2))
      case LLStore(reg1: R, reg2: R) =>
        asm("store " + llt(reg1.t) + " " + llr(reg1) + ", " + llt(reg1.t) + "* " + llr(reg2))
      case LLAlloca(reg: R) =>
        o(reg, "alloca " + llt(reg.t))
    }
  }

  var structs: Map[TStr, String] = Map()
  def llstruct(t: TStr): String = {
    if (structs.contains(t)) return structs(t)
    val name = genid("%.struct")
    structs = structs + (t -> name)
    name
  }

  def apply(file: String, ls: List[LL]) {
    asm.open(file)
    structs.foreach { case (t, n) =>
        asm(n + " = type {" + t.types.map { case (a, b) => llt(b) }.mkString(", ") + "}")
    }
    asm.label("@.str = private constant [4 x i8] c\"%d\\0A\\00\"")
    asm.label("define void @print_i32(i32 %a) nounwind ssp {")
    asm.label("entry:")
    asm("call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([4 x i8]* @.str, i64 0, i64 0), i32 %a) nounwind")
    asm("ret void")
    asm.label("}")
    asm.label("define void @print_i8(i8 %a) nounwind ssp {")
    asm.label("entry:")
    asm("call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([4 x i8]* @.str, i64 0, i64 0), i8 %a) nounwind")
    asm("ret void")
    asm.label("}")

    asm.label("declare i32 @printf(i8*, ...) nounwind")

    asm.label("define i32 @main() nounwind ssp {")
    asm.label("entry:")
    ls.foreach(f)
    asm("ret i32 0")
    asm.label("}")
    asm.close()
  }
}

object genid {
  var id = 0
  def apply(s: String): String = {
    id += 1
    s + id
  }
}
object asm {
  var p: PrintWriter = null
  def open(file: String) {
    p = new PrintWriter(new BufferedWriter(new FileWriter(file)))
  }

  var indent: String = ""

  def apply(s: String, n: String = "") {
    val v = indent + s + "\t" + n + "\n"
    p.print(v)
  }
  def label(s: String) {
    asm.indent = "";
    apply(s)
    asm.indent = "\t";
  }
  def close() {
    p.close()
  }
}

object exec {
  def apply(cmd: String): (Int, String, String) = {
    val p = Runtime.getRuntime().exec(cmd)
    val stdin = (readAll(p.getInputStream()))
    val stderr = (readAll(p.getErrorStream()))
    (p.waitFor(), stdin, stderr)
  }

  def readAll(p: InputStream): String = {
    def f(s: String, i: BufferedReader): String = {
      i.readLine() match {
        case null => s
        case a => f(s + a + "\n", i)
      }
    }
    f("", new BufferedReader(new InputStreamReader(p)))
  }
}
```

## まとめ

構造体の初期化のシンタックスシュガーが出来ました。