Set span for top level annotations generated in PostTyper

This should help avoid macros throwing assertion errors in the case of
annotations not having assigned Spans/positions. Since the annotation is
generated and does not have a position corresponding to the source file,
it inherits Span from the tree to which it is assigned.

Author: jchyb

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

@@ -197,15 +197,24 @@ object Annotations {
 
     def apply(cls: ClassSymbol)(using Context): Annotation =
       apply(cls, Nil)
+    
+    def apply(cls: ClassSymbol, span: Span)(using Context): Annotation =
+      apply(cls, Nil, span)
 
     def apply(cls: ClassSymbol, arg: Tree)(using Context): Annotation =
       apply(cls, arg :: Nil)
+    
+    def apply(cls: ClassSymbol, arg: Tree, span: Span)(using Context): Annotation =
+      apply(cls, arg :: Nil, span)
 
     def apply(cls: ClassSymbol, arg1: Tree, arg2: Tree)(using Context): Annotation =
       apply(cls, arg1 :: arg2 :: Nil)
 
     def apply(cls: ClassSymbol, args: List[Tree])(using Context): Annotation =
       apply(cls.typeRef, args)
+    
+    def apply(cls: ClassSymbol, args: List[Tree], span: Span)(using Context): Annotation =
+      apply(cls.typeRef, args, span)
 
     def apply(atp: Type, arg: Tree)(using Context): Annotation =
       apply(atp, arg :: Nil)
@@ -215,6 +224,9 @@ object Annotations {
 
     def apply(atp: Type, args: List[Tree])(using Context): Annotation =
       apply(New(atp, args))
+    
+    def apply(atp: Type, args: List[Tree], span: Span)(using Context): Annotation =
+      apply(New(atp, args).withSpan(span))
 
     /** Create an annotation where the tree is computed lazily. */
     def deferred(sym: Symbol)(treeFn: Context ?=> Tree): Annotation =
@@ -251,8 +263,8 @@ object Annotations {
         else None
     }
 
-    def makeSourceFile(path: String)(using Context): Annotation =
-      apply(defn.SourceFileAnnot, Literal(Constant(path)))
+    def makeSourceFile(path: String, span: Span)(using Context): Annotation =
+      apply(defn.SourceFileAnnot, Literal(Constant(path)), span)
   }
 
   @sharable val EmptyAnnotation = Annotation(EmptyTree)

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

@@ -395,9 +395,9 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
               if ctx.compilationUnit.source.exists && sym != defn.SourceFileAnnot then
                 val reference = ctx.settings.sourceroot.value
                 val relativePath = util.SourceFile.relativePath(ctx.compilationUnit.source, reference)
-                sym.addAnnotation(Annotation.makeSourceFile(relativePath))
+                sym.addAnnotation(Annotation.makeSourceFile(relativePath, tree.span))
               if Feature.pureFunsEnabled && sym != defn.WithPureFunsAnnot then
-                sym.addAnnotation(Annotation(defn.WithPureFunsAnnot))
+                sym.addAnnotation(Annotation(defn.WithPureFunsAnnot, tree.span))
           else
             if !sym.is(Param) && !sym.owner.isOneOf(AbstractOrTrait) then
               Checking.checkGoodBounds(tree.symbol)
@@ -499,8 +499,8 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
 
     private def annotateExperimental(sym: Symbol)(using Context): Unit =
       if sym.is(Module) && sym.companionClass.hasAnnotation(defn.ExperimentalAnnot) then
-        sym.addAnnotation(defn.ExperimentalAnnot)
-        sym.companionModule.addAnnotation(defn.ExperimentalAnnot)
+        sym.addAnnotation(Annotation(defn.ExperimentalAnnot, sym.span))
+        sym.companionModule.addAnnotation(Annotation(defn.ExperimentalAnnot, sym.span))
 
   }
 }

tests/pos-macros/i16318/Macro_1.scala

@@ -0,0 +1,11 @@
+import scala.quoted.*
+
+final case class Record(a: String, b: Int)
+
+transparent inline def ann[T]: List[Any] = ${ annsImpl[T] }
+
+def annsImpl[T: Type](using Quotes): Expr[List[Any]] = {
+  import quotes.reflect.*
+  val annExpr = TypeRepr.of[T].typeSymbol.annotations.head.asExpr
+  '{ List($annExpr) }
+}

tests/pos-macros/i16318/Test_2.scala

@@ -0,0 +1,2 @@
+def Test =
+  val a = ann[Record]