Eagerly throw error if certain annotations are used on non-hardware types

src/main/scala/chisel3/util/experimental/ForceNames.scala

@@ -3,6 +3,7 @@
 package chisel3.util.experimental
 
 import chisel3.experimental.{annotate, ChiselAnnotation, RunFirrtlTransform}
+import chisel3.internal.Builder
 import firrtl.Mappers._
 import firrtl._
 import firrtl.annotations._
@@ -24,6 +25,7 @@ object forceName {
     * @param name Name to force to
     */
   def apply[T <: chisel3.Element](signal: T, name: String): T = {
+    if (!signal.isSynthesizable) Builder.error(s"Using forceName '$name' on non-hardware value $signal")
     annotate(new ChiselAnnotation with RunFirrtlTransform {
       def toFirrtl = ForceNameAnnotation(signal.toTarget, name)
       override def transformClass: Class[_ <: Transform] = classOf[ForceNamesTransform]
@@ -37,6 +39,7 @@ object forceName {
     * @param signal Signal to name
     */
   def apply[T <: chisel3.Element](signal: T): T = {
+    if (!signal.isSynthesizable) Builder.error(s"Using forceName on non-hardware value $signal")
     annotate(new ChiselAnnotation with RunFirrtlTransform {
       def toFirrtl = ForceNameAnnotation(signal.toTarget, signal.toTarget.ref)
       override def transformClass: Class[_ <: Transform] = classOf[ForceNamesTransform]

src/main/scala/chisel3/util/experimental/decode/decoder.scala

@@ -6,6 +6,7 @@ import chisel3._
 import chisel3.experimental.{annotate, ChiselAnnotation}
 import chisel3.util.{pla, BitPat}
 import chisel3.util.experimental.{getAnnotations, BitSet}
+import chisel3.internal.Builder
 import firrtl.annotations.Annotation
 import logger.LazyLogging
 
@@ -30,6 +31,7 @@ object decoder extends LazyLogging {
       val (plaInput, plaOutput) =
         pla(minimizedTable.table.toSeq, BitPat(minimizedTable.default.value.U(minimizedTable.default.getWidth.W)))
 
+      if (!plaOutput.isSynthesizable) Builder.error(s"Using DecodeTableAnnotation on non-hardware value $plaOutput")
       annotate(new ChiselAnnotation {
         override def toFirrtl: Annotation =
           DecodeTableAnnotation(plaOutput.toTarget, truthTable.toString, minimizedTable.toString)

src/test/scala/chiselTests/experimental/ForceNames.scala

@@ -110,4 +110,18 @@ class ForceNamesSpec extends ChiselFlatSpec {
       )
     }
   }
+  "Force Name of non-hardware value" should "error" in {
+    class Example extends Module {
+      val tpe = UInt(8.W)
+      forceName(tpe, "foobar")
+
+      val in = IO(Input(tpe))
+      val out = IO(Output(tpe))
+      out := in
+    }
+
+    a[ChiselException] shouldBe thrownBy {
+      chisel3.stage.ChiselStage.elaborate(new Example)
+    }
+  }
 }