Make sure inline macros are static methods

Author: nicolasstucki

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

@@ -510,6 +510,8 @@ class ReifyQuotes extends MacroTransformWithImplicits {
           case tree: DefDef if tree.symbol.is(Macro) && level == 0 =>
             tree.rhs match {
               case InlineSplice(_) =>
+                if (!tree.symbol.isStatic)
+                  ctx.error("Inline macro method must be a static method.", tree.pos)
                 markDef(tree)
                 nested(isQuote = true).transform(tree)
                   // check macro code as it if appeared in a quoted context

tests/neg/quote-MacroOverride.scala

@@ -5,7 +5,7 @@ object Test {
     inline def g(): Unit = ()
   }
 
-  class B extends A {
+  object B extends A {
     inline def f() = ~('())  // error: may not override
     override def g() = ()    // error: may not override
   }

tests/pos/quote-interpolator-core/quoted_1.scala renamed to tests/neg/quote-interpolator-core-old.scala

@@ -5,9 +5,9 @@ import scala.quoted._
 object FInterpolation {
 
   implicit class FInterpolatorHelper(val sc: StringContext) extends AnyVal {
-    inline def ff(arg1: Any): String = ~fInterpolation(sc, Seq('(arg1)))
-    inline def ff(arg1: Any, arg2: Any): String = ~fInterpolation(sc, Seq('(arg1), '(arg2)))
-    inline def ff(arg1: Any, arg2: Any, arg3: Any): String = ~fInterpolation(sc, Seq('(arg1), '(arg2), '(arg3)))
+    inline def ff(arg1: Any): String = ~fInterpolation(sc, Seq('(arg1))) // error: Inline macro method must be a static method
+    inline def ff(arg1: Any, arg2: Any): String = ~fInterpolation(sc, Seq('(arg1), '(arg2))) // error: Inline macro method must be a static method
+    inline def ff(arg1: Any, arg2: Any, arg3: Any): String = ~fInterpolation(sc, Seq('(arg1), '(arg2), '(arg3))) // error: Inline macro method must be a static method
     // ...
   }
 
@@ -24,4 +24,4 @@ object FInterpolation {
 
   def hello = "hello"
 
-}
+}

tests/pos/i3916/Macro_1.scala

@@ -2,26 +2,27 @@ import scala.quoted._
 
 import dotty.tools.dotc.quoted.Toolbox._
 
-class Test {
 
-  object Macros {
+object Macros {
 
-    inline def assert(expr: => Boolean): Unit =
-      ~ assertImpl('(expr))
+  inline def assert(expr: => Boolean): Unit =
+    ~ assertImpl('(expr))
 
-    def assertImpl(expr: Expr[Boolean]) =
-      '{ if !(~expr) then throw new AssertionError(s"failed assertion: ${~showExpr(expr)}") }
+  def assertImpl(expr: Expr[Boolean]) =
+    '{ if !(~expr) then throw new AssertionError(s"failed assertion: ${~showExpr(expr)}") }
 
-    def showExpr[T](expr: Expr[T]): Expr[String] = expr.toString.toExpr
+  def showExpr[T](expr: Expr[T]): Expr[String] = expr.toString.toExpr
 
-    inline def power(inline n: Int, x: Double) = ~powerCode(n, '(x))
+  inline def power(inline n: Int, x: Double) = ~powerCode(n, '(x))
 
-    def powerCode(n: Int, x: Expr[Double]): Expr[Double] =
-      if (n == 0) '(1.0)
-      else if (n == 1) x
-      else if (n % 2 == 0) '{ { val y = ~x * ~x; ~powerCode(n / 2, '(y)) } }
-      else '{ ~x * ~powerCode(n - 1, x) }
-  }
+  def powerCode(n: Int, x: Expr[Double]): Expr[Double] =
+    if (n == 0) '(1.0)
+    else if (n == 1) x
+    else if (n % 2 == 0) '{ { val y = ~x * ~x; ~powerCode(n / 2, '(y)) } }
+    else '{ ~x * ~powerCode(n - 1, x) }
+}
+
+class Test {
 
   val program = '{
     import Macros._

tests/pos/i3916/Test_2.scala

@@ -2,7 +2,7 @@ import dotty.tools.dotc.quoted.Toolbox._
 import scala.quoted._
 import Macros._
 
-class Test {
+object Test {
 
   inline def assert(expr: => Boolean): Unit =
     ~ assertImpl('(expr))