Perform full check that a the contents of a macro are valid in PrepareInlineable

Avoid check duplication

Author: nicolasstucki

compiler/src/dotty/tools/dotc/transform/PCPCheckAndHeal.scala

@@ -54,7 +54,10 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
    *  - If inside of a macro definition, check the validity of the macro.
    */
   protected def transformSplice(body: Tree, splice: Tree)(implicit ctx: Context): Tree = {
-    if (level >= 1) {
+    if (level < 0) {
+      ctx.error(s"Splice at level $level is not allowed", splice.sourcePos)
+      splice
+    } else {
       val body1 = transform(body)(spliceContext)
       splice match {
         case Apply(fun: TypeApply, _) if splice.isTerm =>
@@ -65,20 +68,6 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
         case splice: Select => cpy.Select(splice)(body1, splice.name)
       }
     }
-    else {
-      assert(enclosingInlineds.isEmpty, "unexpanded macro")
-      assert(ctx.owner.isInlineMethod)
-      if (Splicer.canBeSpliced(body)) { // level 0 inside an inline definition
-        transform(body)(spliceContext) // Just check PCP
-        splice
-      }
-      else { // level 0 inside an inline definition
-        ctx.error(
-          "Malformed macro call. The contents of the splice ${...} must call a static method and arguments must be quoted or inline.",
-          splice.sourcePos)
-        splice
-      }
-    }
   }
 
   /** If `tree` refers to a locally defined symbol (either directly, or in a pickled type),

compiler/src/dotty/tools/dotc/typer/PrepareInlineable.scala

@@ -251,9 +251,14 @@ object PrepareInlineable {
        */
       object InlineSplice {
         def unapply(tree: Tree)(implicit ctx: Context): Option[Tree] = tree match {
-          case Spliced(code) if Splicer.canBeSpliced(code) =>
-            if (code.symbol.flags.is(Inline))
+          case Spliced(code) =>
+            if (!Splicer.canBeSpliced(code)) {
+              ctx.error(
+                "Malformed macro call. The contents of the splice ${...} must call a static method and arguments must be quoted or inline.",
+                tree.sourcePos)
+            } else if (code.symbol.flags.is(Inline)) {
               ctx.error("Macro cannot be implemented with an `inline` method", code.sourcePos)
+            }
             Some(code)
           case Block(List(stat), Literal(Constants.Constant(()))) => unapply(stat)
           case Block(Nil, expr) => unapply(expr)