Handle passing null for unboxed arguments of extern methods (#2950)

* Reproduce issue #2866 * Remove redundant build settings * clenup
scala-native · Oct 29, 2022 · 688c0ff · 688c0ff
1 parent 4872c8b
commit 688c0ff
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Showing 4 changed files with 40 additions and 8 deletions.
diff --git a/nscplugin/src/main/scala-2/scala/scalanative/nscplugin/NirGenExpr.scala b/nscplugin/src/main/scala-2/scala/scalanative/nscplugin/NirGenExpr.scala
@@ -2443,7 +2443,21 @@ trait NirGenExpr[G <: nsc.Global with Singleton] { self: NirGenPhase[G] =>
         argsp.zip(sym.tpe.params).foreach {
           case (argp, paramSym) =>
             val externType = genExternType(paramSym.tpe)
-            res += toExtern(externType, genExpr(argp))(argp.pos)
+            val arg = (genExpr(argp), Type.box.get(externType)) match {
+              case (value @ Val.Null, Some(unboxedType)) =>
+                externType match {
+                  case Type.Ptr | _: Type.RefKind => value
+                  case _ =>
+                    reporter.warning(
+                      argp.pos,
+                      s"Passing null as argument of ${paramSym}: ${paramSym.tpe} to the extern method is unsafe. " +
+                        s"The argument would be unboxed to primitive value of type $externType."
+                    )
+                    Val.Zero(unboxedType)
+                }
+              case (value, _) => value
+            }
+            res += toExtern(externType, arg)(argp.pos)
         }
 
         res.result()

diff --git a/nscplugin/src/main/scala-3/scala/scalanative/nscplugin/NirGenExpr.scala b/nscplugin/src/main/scala-3/scala/scalanative/nscplugin/NirGenExpr.scala
@@ -1460,7 +1460,21 @@ trait NirGenExpr(using Context) {
           case (argp, paramTpe) =>
             given nir.Position = argp.span
             val externType = genExternType(paramTpe.finalResultType)
-            res += toExtern(externType, genExpr(argp))
+            val arg = (genExpr(argp), Type.box.get(externType)) match {
+              case (value @ Val.Null, Some(unboxedType)) =>
+                externType match {
+                  case Type.Ptr | _: Type.RefKind => value
+                  case _ =>
+                    report.warning(
+                      s"Passing null as argument of type ${paramTpe.show} to the extern method is unsafe. " +
+                        s"The argument would be unboxed to primitive value of type $externType.",
+                      argp.srcPos
+                    )
+                    Val.Zero(unboxedType)
+                }
+              case (value, _) => value
+            }
+            res += toExtern(externType, arg)
         }
         res.result()
       }

diff --git a/project/Settings.scala b/project/Settings.scala
@@ -403,12 +403,6 @@ object Settings {
     Test / unmanagedSourceDirectories += baseDirectory.value
       .getParentFile()
       .getParentFile() / "test-interface-common/src/test/scala",
-    scalacOptions --= scalaVersionsDependendent(scalaVersion.value)(
-      Seq.empty[String]
-    ) {
-      // In Scala 2 enum `Status.value` is defined as `values()`, however in Scala 3 it's `values`
-      case (2, 13) => Seq("-Xfatal-warnings")
-    }
   )
 
   // Projects

diff --git a/unit-tests/native/src/test/scala/scala/scalanative/IssuesTest.scala b/unit-tests/native/src/test/scala/scala/scalanative/IssuesTest.scala
@@ -555,6 +555,16 @@ class IssuesTest {
     assertEquals("class scala.runtime.Null$", classOf[Null].toString())
   }
 
+  @Test def test_Issue2866() = {
+    // In the issue the calls to malloc and srand would fail
+    // becouse null would be passed to extern method taking unboxed type Size/Int
+    import scala.scalanative.libc.stdlib.{malloc, free, srand}
+    val ptr = malloc(null) // CSize -> RawSize should equal to malloc(0)
+    free(ptr) // memory allocated by malloc(0) should always be safe to free
+    srand(null) // CUnsignedInt -> Int should equal to srand(0UL)
+    free(null)
+  }
+
 }
 
 package issue1090 {