Fix #7407: Synthesise a quote context only for macros

compiler/src/dotty/tools/dotc/core/Flags.scala

@@ -442,7 +442,7 @@ object Flags {
     Scala2ExistentialCommon, Mutable, Opaque, Touched, JavaStatic,
     OuterOrCovariant, LabelOrContravariant, CaseAccessor,
     Extension, NonMember, Implicit, Given, Permanent, Synthetic,
-    SuperAccessorOrScala2x, Inline)
+    SuperAccessorOrScala2x, Inline, Macro)
 
   /** Flags that are not (re)set when completing the denotation, or, if symbol is
    *  a top-level class or object, when completing the denotation once the class

compiler/src/dotty/tools/dotc/core/TypeOps.scala

@@ -457,6 +457,9 @@ trait TypeOps { this: Context => // TODO: Make standalone object.
   /** Are we in an inline method body? */
   def inInlineMethod: Boolean = owner.ownersIterator.exists(_.isInlineMethod)
 
+  /** Are we in a macro? */
+  def inMacro: Boolean = owner.ownersIterator.exists(s => s.isInlineMethod && s.is(Macro))
+
   /** Is `feature` enabled in class `owner`?
    *  This is the case if one of the following two alternatives holds:
    *

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

@@ -729,7 +729,7 @@ trait Implicits { self: Typer =>
 
   lazy val synthesizedQuoteContext: SpecialHandler =
     (formal, span) => implicit ctx =>
-      if (ctx.inInlineMethod || enclosingInlineds.nonEmpty) ref(defn.QuoteContext_macroContext)
+      if (ctx.inMacro || enclosingInlineds.nonEmpty) ref(defn.QuoteContext_macroContext)
       else EmptyTree
 
   lazy val synthesizedTupleFunction: SpecialHandler =

tests/neg/i6739.scala

@@ -3,4 +3,4 @@ import scala.quoted._
 inline def assert(expr: => Boolean): Unit =
   ${ assertImpl('expr) } // error: Macro cannot be implemented with an `inline` method
 
-inline def assertImpl(expr: Expr[Boolean]): Expr[Unit] = '{ println("Hello World") }
+inline def assertImpl(expr: Expr[Boolean])(given QuoteContext): Expr[Unit] = '{ println("Hello World") }

tests/neg/i7407.scala

@@ -0,0 +1,2 @@
+def qc(given ctx: scala.quoted.QuoteContext) = println(ctx)
+inline def g = qc  // error: no implicit argument