solution/cw4/compiler.sc
changeset 894 02ef5c3abc51
parent 893 54a483a33763
child 895 2f5a87ecdc81
--- a/solution/cw4/compiler.sc	Fri Oct 28 09:08:13 2022 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,277 +0,0 @@
-// Compiler for JVM
-
-import $file.lexer
-import lexer._
-
-import $file.parser
-import parser._
-
-
-val beginning = """
-.class public XXX.XXX
-.super java/lang/Object
-
-.method public static write(I)V 
-    .limit locals 1 
-    .limit stack 2 
-    getstatic java/lang/System/out Ljava/io/PrintStream; 
-    iload 0
-    invokevirtual java/io/PrintStream/print(I)V 
-    return 
-.end method
-
-.method public static writes(Ljava/lang/String;)V
-    .limit stack 2
-    .limit locals 1
-    getstatic java/lang/System/out Ljava/io/PrintStream;
-    aload 0
-    invokevirtual java/io/PrintStream/print(Ljava/lang/String;)V
-    return
-.end method
-
-.method public static read()I 
-    .limit locals 10 
-    .limit stack 10
-
-    ldc 0 
-    istore 1  ; this will hold our final integer 
-Label1: 
-    getstatic java/lang/System/in Ljava/io/InputStream; 
-    invokevirtual java/io/InputStream/read()I 
-    istore 2 
-    iload 2 
-    ldc 10   ; the newline delimiter 
-    isub 
-    ifeq Label2 
-    iload 2 
-    ldc 32   ; the space delimiter 
-    isub 
-    ifeq Label2
-
-    iload 2 
-    ldc 48   ; we have our digit in ASCII, have to subtract it from 48 
-    isub 
-    ldc 10 
-    iload 1 
-    imul 
-    iadd 
-    istore 1 
-    goto Label1 
-Label2: 
-    ;when we come here we have our integer computed in local variable 1 
-    iload 1 
-    ireturn 
-.end method
-
-.method public static main([Ljava/lang/String;)V
-   .limit locals 200
-   .limit stack 200
-
-; COMPILED CODE STARTS
-
-"""
-
-val ending = """
-; COMPILED CODE ENDS
-   return
-
-.end method
-"""
-
-// Compiler
-
-var counter = -1
-
-def Fresh(x: String) = {
-  counter += 1
-  x ++ "_" ++ counter.toString()
-}
-
-implicit def string_interpolations(sc: StringContext) = new {
-    def i(args: Any*): String = "   " ++ sc.s(args:_*) ++ "\n"
-    def l(args: Any*): String = sc.s(args:_*) ++ ":\n"
-}
-
-type Env = Map[String, Int]
-
-def compile_op(op: String) = op match {
-  case "+" => i"iadd"
-  case "-" => i"isub"
-  case "*" => i"imul"
-  case "/" => i"idiv"
-  case "%" => i"irem"
-}
-
-def compile_aexp(a: AExp, env : Env) : String = a match {
-  case Num(i) => i"ldc $i"
-  case Var(s) => i"iload ${env(s)} \t\t; $s"
-  case Aop(op, a1, a2) => 
-    compile_aexp(a1, env) ++ compile_aexp(a2, env) ++ compile_op(op)
-}
-
-def compile_bexp(b: BExp, env : Env, jmp: String) : String = b match {
-  case True => ""
-  case False => i"goto $jmp"
-  case And(b1, b2) => compile_bexp(b1, env, jmp) ++ compile_bexp(b2, env, jmp)
-  case Or(b1, b2) => {
-    val b1_false = Fresh("Or_second");
-    val or_end = Fresh("Or_end");
-    compile_bexp(b1, env, b1_false) ++
-    i"goto $or_end" ++
-    l"$b1_false" ++
-    compile_bexp(b2, env, jmp) ++
-    l"$or_end"
-  }
-  case Bop("==", a1, a2) => 
-    compile_aexp(a1, env) ++ compile_aexp(a2, env) ++ i"if_icmpne $jmp"
-  case Bop("!=", a1, a2) => 
-    compile_aexp(a1, env) ++ compile_aexp(a2, env) ++ i"if_icmpeq $jmp"
-  case Bop("<", a1, a2) => 
-    compile_aexp(a1, env) ++ compile_aexp(a2, env) ++ i"if_icmpge $jmp"
-  case Bop(">", a1, a2) => 
-    compile_aexp(a1, env) ++ compile_aexp(a2, env) ++ i"if_icmple $jmp"
-}
-
-def compile_stmt(s: Stmt, env: Env) : (String, Env) = s match {
-  case Skip => ("", env)
-  case Assign(x, a) => {
-    val index = env.getOrElse(x, env.keys.size)
-    (compile_aexp(a, env) ++ i"istore $index \t\t; $x", env + (x -> index))
-  } 
-  case If(b, bl1, bl2) => {
-    val if_else = Fresh("If_else")
-    val if_end = Fresh("If_end")
-    val (instrs1, env1) = compile_block(bl1, env)
-    val (instrs2, env2) = compile_block(bl2, env1)
-    (compile_bexp(b, env, if_else) ++
-     instrs1 ++
-     i"goto $if_end" ++
-     l"$if_else" ++
-     instrs2 ++
-     l"$if_end", env2)
-  }
-  case While(b, bl) => {
-    val loop_begin = Fresh("Loop_begin")
-    val loop_end = Fresh("Loop_end")
-    val (instrs1, env1) = compile_block(bl, env)
-    (l"$loop_begin" ++
-     compile_bexp(b, env, loop_end) ++
-     instrs1 ++
-     i"goto $loop_begin" ++
-     l"$loop_end", env1)
-  }
-  case For(id, lower, upper, code) => {
-      val (assignment_code, env1) = compile_stmt(Assign(id, lower), env)  // id := lower;
-      val while_equivalent = While(
-          Or(Bop("<", Var(id), upper), Bop("==", Var(id), upper)),    // while id <= upper do {
-          code ++                                                     //    code  
-          List(
-            Assign(id, Aop("+", Var(id), Num(1)))                     //    id := id + 1
-          ))                                                          // };
-
-      val (while_code, env2) = compile_stmt(while_equivalent, env1)
-      (assignment_code ++ while_code, env2)
-  }
-  case WriteId(x) => (i"iload ${env(x)} \t\t; $x" ++ 
-     i"invokestatic XXX/XXX/write(I)V", env)
-  case WriteString(x) => (s"   ldc ${x}\n" ++
-     i"invokestatic XXX/XXX/writes(Ljava/lang/String;)V", env)
-  case Read(x) => {
-    val index = env.getOrElse(x, env.keys.size) 
-    (i"invokestatic XXX/XXX/read()I" ++ 
-     i"istore $index \t\t; $x", env + (x -> index))
-  }
-}
-
-def compile_block(bl: Block, env: Env) : (String, Env) = bl match {
-  case Nil => ("", env)
-  case s::bl => {
-    val (instrs1, env1) = compile_stmt(s, env)
-    val (instrs2, env2) = compile_block(bl, env1)
-    (instrs1 ++ instrs2, env2)
-  }
-}
-
-def compile(bl: Block, class_name: String) : String = {
-  val instructions = compile_block(bl, Map.empty)._1
-  (beginning ++ instructions ++ ending).replaceAllLiterally("XXX", class_name)
-}
-
-// Compiling and running
-
-import scala.util._
-import scala.sys.process._
-import scala.io
-
-def compile_tofile(bl: Block, class_name: String) = {
-  val output = compile(bl, class_name)
-  val fw = new java.io.FileWriter(class_name + ".j") 
-  fw.write(output) 
-  fw.close()
-}
-
-def compile_all(bl: Block, class_name: String) : Unit = {
-  compile_tofile(bl, class_name)
-  println("compiled ")
-  val test = ("java -jar jasmin.jar " + class_name + ".j").!!
-  println("assembled ")
-}
-
-def time_needed[T](i: Int, code: => T) = {
-  val start = System.nanoTime()
-  for (j <- 1 to i) code
-  val end = System.nanoTime()
-  (end - start)/(i * 1.0e9)
-}
-
-def compile_run(bl: Block, class_name: String) : Unit = {
-  println("Start compilation")
-  compile_all(bl, class_name)
-  println("running")
-  println("Time: " + time_needed(1, ("java " + class_name + "/" + class_name).!))
-}
-
-// ---- Q1
-
-// Fibonacci
-
-val fibonacciProgram = """write "Fib";
-read n;
-minus1 := 0;
-minus2 := 1;
-while n > 0 do {
-  temp := minus2;
-  minus2 := minus1 + minus2;
-  minus1 := temp;
-  n := n - 1
-};
-write "Result";
-write minus2"""
-
-//compile_all(Stmts.parse_all(tokenise(fibonacciProgram)).head, "fib")
-
-val factorialProgram = """write "Factorial";
-read n;
-fact := 1;
-
-while n > 0 do {
-  fact := n * fact;
-  n := n - 1
-};
-
-write "Result";
-write fact
-"""
-
-compile_all(Stmts.parse_all(tokenise(factorialProgram)).head, "factorial")
-
-// ---- Q3
-
-/* compile_run(Stmts.parse_all(tokenise("""for i := 1 upto 10 do {
-  for i := 1 upto 10 do {
-    write i
-  }
-}""")).head, "nestedloop") */
-
-
-compile_run(Stmts.parse_all(tokenise(os.read(os.pwd / "collatz2.while"))).head, "collatz2")