Fix naming of unwrapped val io in Chisel.Modules (#2150)

The removal of virtual method io accidentally made the naming of io in
compatibility mode Bundles sensitive to the prefix at the time of the
first access of the field. It also made .suggestName able to override
the name. This commit fixes that issue by forcing the name of the io
Data to be "io" no matter what.

1 files changed, 11 insertions, 0 deletions

diff --git a/core/src/main/scala/chisel3/internal/Builder.scala b/core/src/main/scala/chisel3/internal/Builder.scala
index 4e68623d..0a0a3f2d 100644
--- a/core/src/main/scala/chisel3/internal/Builder.scala
+++ b/core/src/main/scala/chisel3/internal/Builder.scala
@@ -154,6 +154,17 @@ private[chisel3] trait HasId extends InstanceId {
     this
   }
 
+  // Internal version of .suggestName that can override a user-suggested name
+  // This only exists for maintaining "val io" naming in compatibility-mode Modules without IO
+  // wrapping
+  private[chisel3] def forceFinalName(seed: String): this.type = {
+    // This could be called with user prefixes, ignore them
+    noPrefix {
+      suggested_seed = Some(seed)
+      this.suggestName(seed)
+    }
+  }
+
   /** Computes the name of this HasId, if one exists
     * @param defaultPrefix Optionally provide a default prefix for computing the name
     * @param defaultSeed Optionally provide default seed for computing the name