Disable subtyping, introduce coercions, and type check core (#1219)

See the PR comments.

---------

Co-authored-by: Jonathan Brachthäuser <jonathan@b-studios.de>
Co-authored-by: Philipp Schuster <philipp.schuster@uni-tuebingen.de>

Author: 3 people

.jvmopts

@@ -1,2 +1,4 @@
+-Xms1g
 -Xmx4g
--Xms1g
+-Xss32m
+-Xmx8g

build.sbt

@@ -158,9 +158,9 @@ lazy val effekt: CrossProject = crossProject(JSPlatform, JVMPlatform).in(file("e
       val osName = System.getProperty("os.name").toLowerCase
       val shebang =
         if (osName.contains("win"))
-          "#! /usr/bin/env java -jar\n"
+          "#! /usr/bin/env java -Xss32m -jar\n"
         else
-          "#! /usr/bin/env -S java -jar\n"
+          "#! /usr/bin/env -S java -Xss32m -jar\n"
 
       IO.write(binary, shebang)
       IO.append(binary, IO.readBytes(jarfile))

effekt/jvm/src/main/scala/effekt/Runner.scala

@@ -298,7 +298,7 @@ object LLVMRunner extends Runner[String] {
 
   override def includes(path: File): List[File] = List(path / ".." / "llvm")
 
-  lazy val clangCmd = discoverExecutable(List("clang-20", "clang-19", "clang-18", "clang"), List("--version"))
+  lazy val clangCmd = discoverExecutable(List("clang-21", "clang-20", "clang-19", "clang-18", "clang"), List("--version"))
 
   def checkSetup(): Either[String, Unit] =
     clangCmd.getOrElseAborting { return Left("Cannot find clang. This is required to use the LLVM backend.") }

effekt/jvm/src/test/scala/effekt/LSPTests.scala

@@ -1438,7 +1438,7 @@ class LSPTests extends FunSuite {
              |  Nil,
              |  Nil,
              |  List(
-             |    Val(foo_whatever, Data(Int_whatever, Nil), Return(Literal(42, Data(Int_whatever, Nil))))
+             |    Val(foo_whatever, Return(Literal(42, Data(Int_whatever, Nil))))
              |  ),
              |  List(foo_whatever)
              |)""".stripMargin

effekt/jvm/src/test/scala/effekt/core/OptimizerTests.scala

@@ -151,7 +151,7 @@ class OptimizerTests extends CoreTests {
   test("inline toplevel"){
     val input =
       """ def foo = { () => return 42 }
-        | def main = { () => (foo : () => Unit @ {})() }
+        | def main = { () => (foo : () => Int @ {})() }
         |""".stripMargin
 
     val expected =
@@ -164,7 +164,7 @@ class OptimizerTests extends CoreTests {
   test("inline with argument"){
     val input =
       """ def foo = { (n: Int) => return n:Int }
-        | def main = { () => (foo : (Int) => Unit @ {})(42) }
+        | def main = { () => (foo : (Int) => Int @ {})(42) }
         |""".stripMargin
 
     val expected =
@@ -181,7 +181,7 @@ class OptimizerTests extends CoreTests {
         |   (f : (Int) => Int @ {f})(1)
         | }
         | def main = { () =>
-        |   (hof : (){f : (Int) => Int} => Int @ {})(){ (foo : (Int) => Unit @ {}) }
+        |   (hof : (){f : (Int) => Int} => Int @ {})(){ (foo : (Int) => Int @ {}) }
         | }
         |""".stripMargin
 
@@ -199,7 +199,7 @@ class OptimizerTests extends CoreTests {
         |   (f : (Int) => Int @ {f})(1)
         | }
         | def main = { () =>
-        |   (hof : (){f : (Int) => Int} => Int @ {})(){ (foo : (Int) => Unit @ {}) }
+        |   (hof : (){f : (Int) => Int} => Int @ {})(){ (foo : (Int) => Int @ {}) }
         | }
         |""".stripMargin
 

effekt/jvm/src/test/scala/effekt/core/PatternMatchingTests.scala

@@ -2,9 +2,8 @@ package effekt
 package core
 import effekt.symbols
 import kiama.util.StringSource
-
 import PatternMatchingCompiler.*
-import core.Type.{TBoolean, TInt, TUnit}
+import core.Type.{ TBoolean, TInt, TString, TUnit }
 
 class PatternMatchingTests extends CoreTests {
 
@@ -47,7 +46,7 @@ class PatternMatchingTests extends CoreTests {
   }
 
   test("Sanity check: compiling empty list of clauses") {
-    assertEquals(compile(Nil), core.Hole(effekt.source.Span.missing))
+    assertEquals(compile(Nil, TUnit), core.Hole(TUnit, effekt.source.Span.missing))
   }
 
   test("Simple guard") {
@@ -71,16 +70,16 @@ class PatternMatchingTests extends CoreTests {
       Clause(
         List(
           Condition.Patterns(Map(sc -> Pattern.Any(x.id))),
-          Condition.Val(p.id, TBoolean, trivalPredicate),
+          Condition.Val(p.id, trivalPredicate),
           Condition.Predicate(p)),
         b1, Nil, List(x)),
       Clause(
         List(
           Condition.Patterns(Map(sc -> Pattern.Ignore()))),
-        b2, Nil, List())))
+        b2, Nil, List())), TString)
 
     val expected =
-      Val(p.id, TBoolean, trivalPredicate,
+      Val(p.id, trivalPredicate,
       If(p,
         jump(b1, sc),
         jump(b2)))
@@ -125,21 +124,21 @@ class PatternMatchingTests extends CoreTests {
       Clause(
         List(
           Condition.Patterns(Map(opt -> Pattern.Tag(SomeC, List(), List(SomeC, NoneC), List(Pattern.Any(v.id) -> TInt)))),
-          Condition.Val(p.id, TBoolean, trivalPredicate),
+          Condition.Val(p.id, trivalPredicate),
           Condition.Predicate(p)),
         b1, Nil, List(v)),
       Clause(
         List(
           Condition.Patterns(Map(opt -> Pattern.Ignore()))),
-        b2, Nil, List())))
+        b2, Nil, List())), TUnit)
 
     // opt match {
     //   case Some(tmp) => val p = return v > 0; if (p) { b1(tmp) } else { b2() }
     //   case _ => b2()
     // }
-    val expected = Match(opt,
+    val expected = Match(opt, TUnit,
       List((SomeC, BlockLit(Nil, Nil, List(ValueParam(tmp.id, tmp.tpe)), Nil,
-        Val(p.id, TBoolean, trivalPredicate, If(p,
+        Val(p.id, trivalPredicate, If(p,
           App(b1, Nil, List(tmp), Nil),
           App(b2, Nil, Nil, Nil)))))),
       Some(App(b2, Nil, Nil, Nil)))

effekt/jvm/src/test/scala/effekt/core/PolymorphismBoxingTests.scala

@@ -128,7 +128,7 @@ class RenamerTests extends CoreTests {
         |
         |type Data { X(a:Int, b:Int) }
         |def foo = { () =>
-        |  12 match {
+        |  12 match [Int] {
         |    X : {(aa:Int, bb:Int) => return aa:Int }
         |  }
         |}
@@ -141,7 +141,7 @@ class RenamerTests extends CoreTests {
     val code =
       """module main
         |
-        |def foo = { ['A](a: A) =>
+        |def foo = { ['A](a: Identity[A]) =>
         |  return a:Identity[A]
         |}
         |""".stripMargin

effekt/jvm/src/test/scala/effekt/core/RenamerTests.scala

@@ -76,7 +76,15 @@ class ReparseTests extends CoreTests {
     val renamer = TestRenamer(Names(defaultNames))
     val expectedRenamed = renamer(coreMod)
     val printed = core.PrettyPrinter.format(expectedRenamed).layout
-    val reparsed: ModuleDecl = parse(printed)(using Location.empty)
+    val reparsed: ModuleDecl = try { parse(printed)(using Location.empty) } catch {
+      case e @ TypeError(msg, context) =>
+         println(e.toString)
+         throw e
+      case e =>
+        println("Error while re-parsing:")
+        println(printed)
+        throw e
+    }
     val reparsedRenamed = renamer(reparsed)
     val reparsedPrinted = core.PrettyPrinter.format(reparsedRenamed).layout
     val expectedPrinted = core.PrettyPrinter.format(expectedRenamed).layout