Check type when matching primitive expressions

We might have a reference to an inline val that is not yet constant folded but is sematically equivalent to the value of its type.

Fixes #11854

Author: nicolasstucki

library/src/scala/quoted/FromExpr.scala

@@ -84,11 +84,14 @@ object FromExpr {
     def unapply(expr: Expr[T])(using Quotes) =
       import quotes.reflect._
       def rec(tree: Term): Option[T] = tree match {
-        case Literal(c) if c.value != null => Some(c.value.asInstanceOf[T])
         case Block(Nil, e) => rec(e)
         case Typed(e, _) => rec(e)
         case Inlined(_, Nil, e) => rec(e)
-        case _  => None
+        case _  =>
+          tree.tpe.widenTermRefByName match
+            case ConstantType(c) =>
+              Some(c.value.asInstanceOf[T])
+            case _ => None
       }
       rec(expr.asTerm)
   }

tests/neg/i11854.scala

@@ -1,8 +1,3 @@
-class Bag(seq: Seq[Char])
-
-inline val i = 2
-inline val j: Int = 2 // error
-inline val b: Boolean = true // error
-inline val s: String = "" // error
-inline val bagA = new Bag(Seq('a', 'b', 'c')) // error
-inline val bagB: Bag = new Bag(Seq('a', 'b', 'c')) // error
+inline val str1 = "Hello, "
+inline val str2 = "Scala 3"
+println(Str.concat(str1, str2))

tests/run-macros/expr-map-1.check

@@ -6,9 +6,9 @@ kcolb
 neht
 esle
 lav
-vals
+slav
 fed
-defs
+sfed
 fed
 rab
 yrt

tests/run-macros/expr-map-1/Test_2.scala

@@ -31,7 +31,7 @@ object Test {
 
     rewrite {
       val s: "vals" = "vals"
-      println(s) // prints "foo" not "oof"
+      println(s)
     }
 
     rewrite {
@@ -41,7 +41,7 @@ object Test {
 
     rewrite {
       def s: "defs" = "defs"
-      println(s) // prints "foo" not "oof"
+      println(s)
     }
 
     rewrite {

tests/run-macros/i11856/Main_2.scala

@@ -0,0 +1,8 @@
+@main def Test: Unit =
+  inline def str1 = "Hello, "
+  inline val str2 = "Scala 3"
+  println(Str.concat(str1, str2))
+
+  inline def i1 = 1
+  inline val i2 = 2
+  println(I.sum(i1, i2))

tests/run-macros/i11856/Test_1.scala

@@ -0,0 +1,19 @@
+import scala.quoted.*
+
+object Str:
+    inline def concat(inline a: String, inline b: String): String =
+        ${ evalConcat('a, 'b) }
+
+    def evalConcat(expra: Expr[String], exprb: Expr[String])(using Quotes): Expr[String] =
+        val a = expra.valueOrError
+        val b = exprb.valueOrError
+        Expr(a ++ b)
+
+object I:
+  inline def sum(inline a: Int, inline b: Int): Int =
+      ${ evalConcat('a, 'b) }
+
+  def evalConcat(expra: Expr[Int], exprb: Expr[Int])(using Quotes): Expr[Int] =
+      val a = expra.valueOrError
+      val b = exprb.valueOrError
+      Expr(a + b)