Fix #4803: Remove restriction

Allow top-level ~ in and non static transparent method:
* Class methods (including inner and anonymous classes)
* Methods in def/val/var

Author: nicolasstucki

bench/tests/power-macro/PowerMacro.scala

@@ -6,7 +6,7 @@ object PowerMacro {
 
   def powerCode(n: Long, x: Expr[Double]): Expr[Double] =
     if (n == 0) '(1.0)
-    else if (n % 2 == 0) '{ { val y = ~x * ~x; ~powerCode(n / 2, '(y)) } }
+    else if (n % 2 == 0) '{ val y = ~x * ~x; ~powerCode(n / 2, '(y)) }
     else '{ ~x * ~powerCode(n - 1, x) }
 
 }

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

@@ -565,11 +565,11 @@ class ReifyQuotes extends MacroTransformWithImplicits {
           case _: Import =>
             tree
           case tree: DefDef if tree.symbol.is(Macro) && level == 0 =>
+            if (enclosingInlineds.nonEmpty)
+              return EmptyTree // Already checked at definition site and already inlined
             markDef(tree)
             tree.rhs match {
               case InlineSplice(_) =>
-                if (!tree.symbol.isStatic)
-                  ctx.error("Transparent macro method must be a static method.", tree.pos)
                 mapOverTree(enteredSyms) // Ignore output, only check PCP
                 cpy.DefDef(tree)(rhs = defaultValue(tree.rhs.tpe))
               case _ =>

tests/neg/quote-non-static-macro.scala renamed to tests/pos/quote-non-static-macro.scala

@@ -1,15 +1,15 @@
 import scala.quoted._
 
 class Foo {
-  transparent def foo: Unit = ~Foo.impl // error
+  transparent def foo: Unit = ~Foo.impl
   object Bar {
-    transparent def foo: Unit = ~Foo.impl // error
+    transparent def foo: Unit = ~Foo.impl
   }
 }
 
 object Foo {
   class Baz {
-    transparent def foo: Unit = ~impl // error
+    transparent def foo: Unit = ~impl
   }
   object Quox {
     transparent def foo: Unit = ~Foo.impl

tests/run/i4803.check

@@ -0,0 +1,8 @@
+1.0
+1.5
+2.25
+7.59375
+1.0
+1.5
+2.25
+7.59375

tests/run/i4803/App_2.scala

@@ -0,0 +1,20 @@
+
+class Num2(x: Double) {
+  transparent def power(transparent n: Long) = ~PowerMacro.powerCode('(x), n)
+}
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val n = new Num(1.5)
+    println(n.power(0))
+    println(n.power(1))
+    println(n.power(2))
+    println(n.power(5))
+
+    val n2 = new Num2(1.5)
+    println(n.power(0))
+    println(n.power(1))
+    println(n.power(2))
+    println(n.power(5))
+  }
+}

tests/run/i4803/Macro_1.scala

@@ -0,0 +1,12 @@
+import scala.quoted._
+
+object PowerMacro {
+  def powerCode(x: Expr[Double], n: Long): Expr[Double] =
+    if (n == 0) '(1.0)
+    else if (n % 2 == 0) '{ val y = ~x * ~x; ~powerCode('(y), n / 2) }
+    else '{ ~x * ~powerCode(x, n - 1) }
+}
+
+class Num(x: Double) {
+  transparent def power(transparent n: Long) = ~PowerMacro.powerCode('(x), n)
+}

tests/run/i4803b.check

@@ -0,0 +1,4 @@
+1.0
+1.5
+2.25
+7.59375

tests/run/i4803b/App_2.scala

@@ -0,0 +1,18 @@
+
+
+class Nums {
+  class Num(x: Double) {
+    transparent def power(transparent n: Long) = ~PowerMacro.powerCode('(x), n)
+  }
+}
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val nums = new Nums
+    val n = new nums.Num(1.5)
+    println(n.power(0))
+    println(n.power(1))
+    println(n.power(2))
+    println(n.power(5))
+  }
+}

tests/run/i4803b/Macro_1.scala

@@ -0,0 +1,8 @@
+import scala.quoted._
+
+object PowerMacro {
+  def powerCode(x: Expr[Double], n: Long): Expr[Double] =
+    if (n == 0) '(1.0)
+    else if (n % 2 == 0) '{ val y = ~x * ~x; ~powerCode('(y), n / 2) }
+    else '{ ~x * ~powerCode(x, n - 1) }
+}

tests/run/i4803c.check

@@ -0,0 +1,8 @@
+1.0
+1.5
+2.25
+7.59375
+1.0
+1.5
+2.25
+7.59375