Disallow phase inconsitent inline parameters

Author: nicolasstucki

community-build/community-projects/scalatest

@@ -88,8 +88,6 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
     tree match {
       case Quoted(_) | Spliced(_)  =>
         tree
-      case tree: RefTree if tree.symbol.isAllOf(InlineParam) =>
-        tree
       case _: This =>
         assert(checkSymLevel(tree.symbol, tree.tpe, tree.sourcePos).isEmpty)
         tree
@@ -197,10 +195,8 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
     case Some(l) =>
       l == level ||
         level == -1 && (
-            // here we assume that Splicer.canBeSpliced was true before going to level -1,
-            // this implies that all non-inline arguments are quoted and that the following two cases are checked
-            // on inline parameters or type parameters.
-            sym.is(Param) ||
+            // here we assume that Splicer.checkValidMacroBody was true before going to level -1,
+            // this implies that all arguments are quoted.
             sym.isClass // reference to this in inline methods
           )
     case None =>

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

@@ -49,6 +49,9 @@ object Splicer {
       catch {
         case ex: CompilationUnit.SuspendException =>
           throw ex
+        case ex: scala.quoted.StopQuotedContext if ctx.reporter.hasErrors =>
+           // errors have been emitted
+          EmptyTree
         case ex: StopInterpretation =>
           ctx.error(ex.msg, ex.pos)
           EmptyTree
@@ -349,6 +352,8 @@ object Splicer {
           throw new StopInterpretation(sw.toString, pos)
         case ex: InvocationTargetException =>
           ex.getTargetException match {
+            case ex: scala.quoted.StopQuotedContext =>
+              throw ex
             case MissingClassDefinedInCurrentRun(sym) =>
               if (ctx.settings.XprintSuspension.value)
                 ctx.echo(i"suspension triggered by a dependency on $sym", pos)

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

@@ -19,7 +19,6 @@ import dotty.tools.dotc.util.Spans._
 import dotty.tools.dotc.util.{Property, SourcePosition}
 import dotty.tools.dotc.transform.SymUtils._
 import dotty.tools.dotc.typer.Implicits.SearchFailureType
-import dotty.tools.dotc.typer.Inliner
 
 import scala.collection.mutable
 import scala.annotation.constructorOnly

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

@@ -229,8 +229,8 @@ private[quoted] object Matcher {
           case (While(cond1, body1), While(cond2, body2)) =>
             cond1 =?= cond2 && body1 =?= body2
 
-          case (New(tpt1), New(tpt2)) =>
-            tpt1 =?= tpt2
+          case (New(tpt1), New(tpt2)) if tpt1.tpe.typeSymbol == tpt2.tpe.typeSymbol =>
+            matched
 
           case (This(_), This(_)) if scrutinee.symbol == pattern.symbol =>
             matched

library/src/scala/internal/quoted/Matcher.scala

@@ -18,6 +18,14 @@ class Expr[+T] private[scala] {
    */
   final def getValue[U >: T](given qctx: QuoteContext, valueOf: ValueOfExpr[U]): Option[U] = valueOf(this)
 
+  /** Return the value of this expression.
+   *
+   *  Emits an error error and throws if the expression does not contain a value or contains side effects.
+   *  Otherwise returns the value.
+   */
+  final def value[U >: T](given qctx: QuoteContext, valueOf: ValueOfExpr[U]): U =
+    valueOf(this).getOrElse(qctx.throwError(s"Expected a known value. \n\nThe value of: $show\ncould not be recovered using $valueOf", this))
+
   /** Pattern matches `this` against `that`. Effectively performing a deep equality check.
    *  It does the equivalent of
    *  ```

library/src/scala/quoted/Expr.scala

@@ -22,7 +22,7 @@ class QuoteContext(val tasty: scala.tasty.Reflection) {
     tpe.unseal.show(syntaxHighlight)
   }
 
-  /** Report an error */
+  /** Report an error at the position of the macro expansion */
   def error(msg: => String): Unit = {
     import tasty.{_, given}
     tasty.error(msg, rootPosition)(given rootContext)
@@ -34,6 +34,17 @@ class QuoteContext(val tasty: scala.tasty.Reflection) {
     tasty.error(msg, expr.unseal.pos)(given rootContext)
   }
 
+  /** Report an error at the position of the macro expansion and throws a StopQuotedContext */
+  def throwError(msg: => String): Nothing = {
+    error(msg)
+    throw new StopQuotedContext
+  }
+  /** Report an error at the on the position of `expr` and throws a StopQuotedContext */
+  def throwError(msg: => String, expr: Expr[_]): Nothing = {
+    error(msg, expr)
+    throw new StopQuotedContext
+  }
+
   /** Report a warning */
   def warning(msg: => String): Unit = {
     import tasty.{_, given}

library/src/scala/quoted/QuoteContext.scala

@@ -0,0 +1,4 @@
+package scala.quoted
+
+/** Stop code generation after an error has been reported */
+class StopQuotedContext extends Throwable

library/src/scala/quoted/StopQuotedContext.scala

@@ -0,0 +1,30 @@
+package scala.quoted
+package matching
+
+/** Literal sequence of literal constant value expressions */
+object ValueSeq {
+
+  /** Matches literal sequence of literal constant value expressions and return a sequence of values.
+   *
+   *  Usage:
+   *  ```scala
+   *  inline def sum(args: Int*): Int = ${ sumExpr('args) }
+   *  def sumExpr(argsExpr: Expr[Seq[Int]])(given QuoteContext): Expr[Int] = argsExpr match
+   *    case ValueSeq(args) =>
+   *      // args: Seq[Int]
+   *      ...
+   *  }
+   *  ```
+   */
+  def unapply[T](expr: Expr[Seq[T]])(given valueOf: ValueOfExpr[T], qctx: QuoteContext): Option[Seq[T]] = expr match {
+    case ExprSeq(elems) =>
+      elems.foldRight(Option(List.empty[T])) { (elem, acc) =>
+        (elem, acc) match {
+          case (ValueOfExpr(value), Some(lst)) => Some(value :: lst)
+          case (_, _) => None
+        }
+      }
+    case _ => None
+  }
+
+}