Track splice calls instead of inline calls

The real thing that needs to be tracked for cyclic dependencies
are calls to spliced methods. Move the suspend machinery from
inline calls to these.

Author: odersky

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

@@ -70,10 +70,6 @@ object Inliner {
    */
   def inlineCall(tree: Tree)(implicit ctx: Context): Tree = {
     if (tree.symbol == defn.CompiletimeTesting_typeChecks) return Intrinsics.typeChecks(tree)
-    if tree.symbol.is(Macro) && tree.symbol.isDefinedInCurrentRun then
-      if ctx.compilationUnit.source.file == tree.symbol.associatedFile then
-        ctx.error("Cannot call macro defined in the same source file", tree.sourcePos)
-      ctx.compilationUnit.suspend()
 
    /** Set the position of all trees logically contained in the expansion of
     *  inlined call `call` to the position of `call`. This transform is necessary
@@ -1241,35 +1237,25 @@ class Inliner(call: tpd.Tree, rhsToInline: tpd.Tree)(implicit ctx: Context) {
     assert(level == 0)
     val inlinedFrom = enclosingInlineds.last
     val ctx1 = tastyreflect.MacroExpansion.context(inlinedFrom)
-
     val dependencies = macroDependencies(body)
 
-    if (dependencies.nonEmpty) {
-      var location = inlinedFrom.symbol
-      if (location.isLocalDummy) location = location.owner
-
-      val msg =
-        em"""Failed to expand macro. This macro depends on an implementation that is defined in the same project and not yet compiled.
-           |In particular ${inlinedFrom.symbol} depends on ${dependencies.map(_.show).mkString(", ")}.
-           |
-           |Moving ${dependencies.map(_.show).mkString(", ")} to a different project would fix this.
-           |""".stripMargin
-      ctx.error(msg, inlinedFrom.sourcePos)
-      EmptyTree
-    }
-    else {
-      val evaluatedSplice = Splicer.splice(body, inlinedFrom.sourcePos, MacroClassLoader.fromContext)(ctx1)
+    if dependencies.nonEmpty then
+      for sym <- dependencies do
+        if ctx.compilationUnit.source.file == sym.associatedFile then
+          ctx.error(em"Cannot call macro $sym defined in the same source file", body.sourcePos)
+      ctx.compilationUnit.suspend() // this throws a SuspendException
 
-      val inlinedNormailizer = new TreeMap {
-        override def transform(tree: tpd.Tree)(implicit ctx: Context): tpd.Tree = tree match {
-          case Inlined(EmptyTree, Nil, expr) if enclosingInlineds.isEmpty => transform(expr)
-          case _ => super.transform(tree)
-        }
+    val evaluatedSplice = Splicer.splice(body, inlinedFrom.sourcePos, MacroClassLoader.fromContext)(ctx1)
+
+    val inlinedNormailizer = new TreeMap {
+      override def transform(tree: tpd.Tree)(implicit ctx: Context): tpd.Tree = tree match {
+        case Inlined(EmptyTree, Nil, expr) if enclosingInlineds.isEmpty => transform(expr)
+        case _ => super.transform(tree)
       }
-      val normalizedSplice = inlinedNormailizer.transform(evaluatedSplice)
-      if (normalizedSplice.isEmpty) normalizedSplice
-      else normalizedSplice.withSpan(span)
     }
+    val normalizedSplice = inlinedNormailizer.transform(evaluatedSplice)
+    if (normalizedSplice.isEmpty) normalizedSplice
+    else normalizedSplice.withSpan(span)
   }
 
   /** Return the set of symbols that are refered at level -1 by the tree and defined in the current run.