Supporting export (#58)

evalTop runs exported function now

benchmarks/wasm/ack.wat

@@ -51,7 +51,7 @@
   (global (;1;) i32 (i32.const 1048576))
   (global (;2;) i32 (i32.const 1048576))
   (export "memory" (memory 0))
-  (export "ack" (func $ack))
-  (export "real_main" (func $real_main))
+  (export "ack" (func 0))
+  (export "real_main" (func 1))
   (export "__data_end" (global 1))
   (export "__heap_base" (global 2)))

benchmarks/wasm/pow.wat

@@ -37,7 +37,7 @@
   (global (;1;) i32 (i32.const 1048576))
   (global (;2;) i32 (i32.const 1048576))
   (export "memory" (memory 0))
-  (export "power" (func $power))
-  (export "real_main" (func $real_main))
+  (export "power" (func 0))
+  (export "real_main" (func 1))
   (export "__data_end" (global 1))
   (export "__heap_base" (global 2)))

benchmarks/wasm/return.wat

@@ -12,5 +12,5 @@
     call 0
     unreachable
   )
-  (start 1)
+  (export "$real_main" (func 1))
 )

grammar/gen-wat-parser.sh

@@ -2,14 +2,21 @@
 #
 ANTLR4=antlr-4.13.0-complete.jar
 
-java20 -jar $ANTLR4 WatLexer.g4
-java20 -jar $ANTLR4 -visitor WatParser.g4
+java -jar $ANTLR4 WatLexer.g4
+java -jar $ANTLR4 -visitor WatParser.g4
 
 DST=../src/main/java/wasm/
 echo "Copy WAT parsers into $DST"
 
 for file in "WatLexer.java" "WatParserBaseVisitor.java" "WatParserListener.java" "WatParserBaseListener.java" "WatParser.java" "WatParserVisitor.java"
 do
-  sed -i "1ipackage gensym.wasm;$line" $file
-  cp $file $DST/$file
+  if [[ "$OSTYPE" == "darwin"* ]]; then
+    sed -i '' $'1i\\\npackage gensym.wasm;\n' $file
+  else
+    sed -i "1ipackage gensym.wasm;$line" $file
+  fi
+  cp $file "$DST/$file"
+  rm $file
 done
+
+rm *.tokens *.interp

src/main/scala/wasm/AST.scala

@@ -14,11 +14,11 @@ case class TypeDef(id: Option[String], tipe: FuncType) extends Definition
 case class Table(id: Option[String], f: TableField) extends Definition
 case class Memory(id: Option[String], f: MemoryField) extends Definition
 case class Global(id: Option[String], f: GlobalField) extends Definition
-case class Elem(id: Option[Int], offset: List[Instr], elemList: ElemList)
-    extends Definition
+case class Elem(id: Option[Int], offset: List[Instr], elemList: ElemList) extends Definition
 case class Data(id: Option[String], value: String) extends Definition
 case class Start(id: Int) extends Definition
 case class Import(mod: String, name: String, desc: ImportDesc) extends Definition
+case class Export(name: String, desc: ExportDesc) extends Definition
 // FIXME: missing top-level module fields, see WatParser.g4
 
 abstract class ImportDesc extends WIR
@@ -30,16 +30,9 @@ case class ElemListFunc(funcs: List[String]) extends ElemList
 case class ElemListExpr(exprs: List[List[Instr]]) extends ElemList
 
 abstract class FuncField extends WIR
-case class FuncBodyDef(tipe: FuncType,
-                       localNames: List[String],
-                       locals: List[ValueType],
-                       body: List[Instr])
-    extends FuncField
-case class FunInlineImport(mod: String,
-                           name: String,
-                           typeUse: Option[Int],
-                           imports: Any /*FIXME*/ )
+case class FuncBodyDef(tipe: FuncType, localNames: List[String], locals: List[ValueType], body: List[Instr])
     extends FuncField
+case class FunInlineImport(mod: String, name: String, typeUse: Option[Int], imports: Any /*FIXME*/ ) extends FuncField
 case class FunInlineExport(fd: List[FuncDef]) extends FuncField
 
 abstract class TableField extends WIR
@@ -69,17 +62,11 @@ case object Alloc extends Instr
 case object Free extends Instr
 case class Select(ty: Option[List[ValueType]]) extends Instr
 case class Block(ty: Option[ValueType], instrs: List[Instr]) extends Instr
-case class IdBlock(id: Int, ty: Option[ValueType], instrs: List[Instr])
-    extends Instr
+case class IdBlock(id: Int, ty: Option[ValueType], instrs: List[Instr]) extends Instr
 case class Loop(ty: Option[ValueType], instrs: List[Instr]) extends Instr
-case class IdLoop(id: Int, ty: Option[ValueType], instrs: List[Instr])
-    extends Instr
-case class If(ty: Option[ValueType],
-              thenInstrs: List[Instr],
-              elseInstrs: List[Instr])
-    extends Instr
-case class IdIf(ty: Option[ValueType], thenInstrs: IdBlock, elseInstrs: IdBlock)
-    extends Instr
+case class IdLoop(id: Int, ty: Option[ValueType], instrs: List[Instr]) extends Instr
+case class If(ty: Option[ValueType], thenInstrs: List[Instr], elseInstrs: List[Instr]) extends Instr
+case class IdIf(ty: Option[ValueType], thenInstrs: IdBlock, elseInstrs: IdBlock) extends Instr
 // FIXME: labelId can be string?
 case class Br(labelId: Int) extends Instr
 case class BrIf(labelId: Int) extends Instr
@@ -221,16 +208,8 @@ case object SX extends Extension
 case object ZX extends Extension
 
 abstract class MemOp(align: Int, offset: Int) extends WIR
-case class StoreOp(align: Int,
-                   offset: Int,
-                   tipe: NumType,
-                   pack_size: Option[PackSize])
-    extends MemOp(align, offset)
-case class LoadOp(align: Int,
-                  offset: Int,
-                  tipe: NumType,
-                  pack_size: Option[PackSize],
-                  extension: Option[Extension])
+case class StoreOp(align: Int, offset: Int, tipe: NumType, pack_size: Option[PackSize]) extends MemOp(align, offset)
+case class LoadOp(align: Int, offset: Int, tipe: NumType, pack_size: Option[PackSize], extension: Option[Extension])
     extends MemOp(align, offset)
 
 // Types
@@ -255,10 +234,7 @@ case class NumType(kind: NumKind) extends ValueType
 case class VecType(kind: VecKind) extends ValueType
 case class RefType(kind: RefKind) extends ValueType
 
-case class FuncType(argNames /*optional*/: List[String],
-                    inps: List[ValueType],
-                    out: List[ValueType])
-    extends WasmType
+case class FuncType(argNames /*optional*/: List[String], inps: List[ValueType], out: List[ValueType]) extends WasmType
 
 case class GlobalType(ty: ValueType, mut: Boolean) extends WasmType
 
@@ -302,3 +278,10 @@ case class I32V(value: Int) extends Num
 case class I64V(value: Long) extends Num
 case class F32V(value: Float) extends Num
 case class F64V(value: Double) extends Num
+
+// Exports
+abstract class ExportDesc extends WIR
+case class ExportFunc(i: Int) extends ExportDesc
+case class ExportTable(i: Int) extends ExportDesc
+case class ExportMemory(i: Int) extends ExportDesc
+case class ExportGlobal(i: Int) extends ExportDesc

src/main/scala/wasm/Memory.scala

@@ -86,7 +86,6 @@ object RTMemory {
   def apply(): RTMemory = this.apply(1024)
   def apply(size: Int): RTMemory = this.apply(size, None)
   def apply(size: Int, maxSize: Option[Int]): RTMemory = {
-    new RTMemory(RTMemoryType(size, maxSize),
-                 ArrayBuffer.fill[Byte](size * pageSize.toInt)(0))
+    new RTMemory(RTMemoryType(size, maxSize), ArrayBuffer.fill[Byte](size * pageSize.toInt)(0))
   }
 }

src/main/scala/wasm/MiniWasm.scala

@@ -14,6 +14,7 @@ case class ModuleInstance(
     funcs: HashMap[Int, WIR],
     memory: List[RTMemory] = List(RTMemory()),
     globals: List[RTGlobal] = List(),
+    exports: List[Export] = List()
 )
 
 object Primtives {
@@ -230,8 +231,10 @@ object Evaluator {
         val mem = frame.module.memory.head
         val oldSize = mem.size
         mem.grow(delta) match {
-          case Some(e) => eval(rest, I32V(-1) :: newStack, frame, kont, trail, ret)
-          case _       => eval(rest, I32V(oldSize) :: newStack, frame, kont, trail, ret)
+          case Some(e) =>
+            eval(rest, I32V(-1) :: newStack, frame, kont, trail, ret)
+          case _ =>
+            eval(rest, I32V(oldSize) :: newStack, frame, kont, trail, ret)
         }
       case MemoryFill =>
         val I32V(value) :: I32V(offset) :: I32V(size) :: newStack = stack
@@ -274,26 +277,24 @@ object Evaluator {
         eval(rest, stack, frame, kont, trail, ret)
       case Unreachable => throw Trap()
       case Block(ty, inner) =>
-        val k: Cont[Ans] = (retStack) =>
-          eval(rest, retStack.take(ty.toList.size) ++ stack, frame, kont, trail, ret)
+        val k: Cont[Ans] = (retStack) => eval(rest, retStack.take(ty.toList.size) ++ stack, frame, kont, trail, ret)
         // TODO: block can take inputs too
-        eval(inner, List(), frame, k, k :: trail, ret+1)
+        eval(inner, List(), frame, k, k :: trail, ret + 1)
       case Loop(ty, inner) =>
         // We construct two continuations, one for the break (to the begining of the loop),
         // and one for fall-through to the next instruction following the syntactic structure
         // of the program.
         val restK: Cont[Ans] = (retStack) => eval(rest, retStack.take(ty.toList.size) ++ stack, frame, kont, trail, ret)
         def loop(stack: List[Value]): Ans = {
           val k: Cont[Ans] = (retStack) => loop(retStack.take(ty.toList.size))
-          eval(inner, stack, frame, restK, k :: trail, ret+1)
+          eval(inner, stack, frame, restK, k :: trail, ret + 1)
         }
         loop(List())
       case If(ty, thn, els) =>
         val I32V(cond) :: newStack = stack
         val inner = if (cond != 0) thn else els
-        val k: Cont[Ans] = (retStack) =>
-          eval(rest, retStack.take(ty.toList.size) ++ newStack, frame, kont, trail, ret)
-        eval(inner, List(), frame, k, k :: trail, ret+1)
+        val k: Cont[Ans] = (retStack) => eval(rest, retStack.take(ty.toList.size) ++ newStack, frame, kont, trail, ret)
+        eval(inner, List(), frame, k, k :: trail, ret + 1)
       case Br(label) =>
         trail(label)(stack)
       case BrIf(label) =>
@@ -311,8 +312,7 @@ object Evaluator {
         val newStack = stack.drop(ty.inps.size)
         val frameLocals = args ++ locals.map(zero(_))
         val newFrame = Frame(frame.module, ArrayBuffer(frameLocals: _*))
-        val newK: Cont[Ans] = (retStack) =>
-          eval(rest, retStack.take(ty.out.size) ++ newStack, frame, kont, trail, ret)
+        val newK: Cont[Ans] = (retStack) => eval(rest, retStack.take(ty.out.size) ++ newStack, frame, kont, trail, ret)
         // We push newK on the trail since function creates a new block to escape
         // (more or less like `return`)
         eval(body, List(), newFrame, newK, List(newK), 0)
@@ -335,21 +335,32 @@ object Evaluator {
   // otherwise, we look up the top-level `start` instruction to locate the entry point.
   def evalTop[Ans](module: Module, halt: Cont[Ans], main: Option[String] = None): Ans = {
     val instrs = main match {
-      case Some(_) => module.definitions.flatMap({
-          case FuncDef(`main`, FuncBodyDef(_, _, _, body)) =>
+      case Some(func_name) =>
+        module.definitions.flatMap({
+          case Export(`func_name`, ExportFunc(fid)) =>
             println(s"Entering function $main")
-            body
+            module.funcEnv(fid) match {
+              case FuncDef(_, FuncBodyDef(_, _, _, body)) => body
+              case _ =>
+                throw new Exception("Entry function has no concrete body")
+            }
           case _ => List()
         })
-      case None => module.definitions.flatMap({
-        case Start(id) => module.funcEnv(id) match {
-          case FuncDef(_, FuncBodyDef(_, _, _, body)) =>
+      case None =>
+        module.definitions.flatMap({
+          case Start(id) =>
             println(s"Entering unnamed function $id")
-            body
-          case _ => throw new Exception("Start function has no concrete definition")
-        }
-        case _ => List()
-      })
+            module.funcEnv(id) match {
+              case FuncDef(_, FuncBodyDef(_, _, _, body)) => body
+              case _ =>
+                throw new Exception("Entry function has no concrete body")
+            }
+          case _ => List()
+        })
+    }
+
+    if (instrs.isEmpty) {
+      println("Warning: nothing is executed")
     }
 
     val types = List()
@@ -364,8 +375,8 @@ object Evaluator {
         case Global(_, GlobalValue(ty, e)) =>
           (e.head) match {
             case Const(c) => RTGlobal(ty, c)
-            // Q: What is the default behavior if case in non exhaustive
-            case _        => ???
+            // Q: What is the default behavior if case in non-exhaustive
+            case _ => ???
           }
       })
       .toList

src/main/scala/wasm/Parser.scala

@@ -566,6 +566,28 @@ class GSWasmVisitor extends WatParserBaseVisitor[WIR] {
     val field = visitGlobalField(ctx.globalField)
     Global(name, field)
   }
+
+  override def visitExport_(ctx: Export_Context): WIR = {
+    val name: String  = ctx.name.getText.substring(1).dropRight(1)
+    val desc = visitExportDesc(ctx.exportDesc).asInstanceOf[ExportDesc]
+    Export(name, desc)
+  }
+
+  override def visitExportDesc(ctx: ExportDescContext): WIR = {
+    val id = if (ctx.idx.VAR() != null) {
+      println(s"Warning: we don't support labeling yet")
+      throw new RuntimeException("Unsupported")
+    } else {
+      getVar(ctx.idx()).toInt
+    }
+    if (ctx.FUNC != null) ExportFunc(id)
+    else if (ctx.TABLE != null)  ExportTable(id)
+    else if (ctx.MEMORY != null)  ExportMemory(id)
+    else if (ctx.GLOBAL != null) ExportGlobal(id)
+    else error
+
+  }
+
 }
 
 object Parser {

src/test/scala/genwasym/TestEval.scala

@@ -14,9 +14,7 @@ import collection.mutable.ArrayBuffer
 import org.scalatest.FunSuite
 
 class TestEval extends FunSuite {
-  def testFile(filename: String,
-               main: Option[String] = None,
-               expected: Option[Int] = None) = {
+  def testFile(filename: String, main: Option[String] = None, expected: Option[Int] = None) = {
     val module = Parser.parseFile(filename)
     //println(module)
     val haltK: Evaluator.Cont[Unit] = stack => {
@@ -32,8 +30,8 @@ class TestEval extends FunSuite {
   // TODO: the power test can be used to test the stack
   // For now: 2^10 works, 2^100 results in 0 (TODO: why?),
   // and 2^1000 results in a stack overflow
-  test("ack") { testFile("./benchmarks/wasm/ack.wat", Some("$real_main"), Some(7)) }
-  test("power") { testFile("./benchmarks/wasm/pow.wat", Some("$real_main"), Some(1024)) }
+  test("ack") { testFile("./benchmarks/wasm/ack.wat", Some("real_main"), Some(7)) }
+  test("power") { testFile("./benchmarks/wasm/pow.wat", Some("real_main"), Some(1024)) }
   test("start") { testFile("./benchmarks/wasm/start.wat") }
   test("fact") { testFile("./benchmarks/wasm/fact.wat", None, Some(120)) }
   test("loop") { testFile("./benchmarks/wasm/loop.wat", None, Some(10)) }
@@ -45,7 +43,7 @@ class TestEval extends FunSuite {
 
   test("return") {
     intercept[gensym.wasm.miniwasm.Trap] {
-      testFile("./benchmarks/wasm/return.wat", None, None)
+      testFile("./benchmarks/wasm/return.wat", Some("$real_main"), None)
     }
   }