Change when/switch thunk type to Any (#1308)

* Change when thunks return type to Any

Changes the type of the thunk for when and WhenContext methods from
call-by-name Unit to call-by-name Any. This prevents a
warning (-Ywarn-value-discard) where a when thunk is returning
something other than Unit that is then discarded, e.g., another
WhenContext.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

* Change switch thunk return to type to Any

Changes the type of switch thunks from call-by-name Unit to
call-by-name Any. This prevents a warning (-Ywarn-value-discard) when
the internals of a switch block return something other than Unit which
is then discarded.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/chiselFrontend/src/main/scala/chisel3/When.scala b/chiselFrontend/src/main/scala/chisel3/When.scala
index 50e13a1f..ea243bbe 100644
--- a/chiselFrontend/src/main/scala/chisel3/When.scala
+++ b/chiselFrontend/src/main/scala/chisel3/When.scala
@@ -28,7 +28,7 @@ object when {  // scalastyle:ignore object.name
     * }}}
     */
 
-  def apply(cond: => Bool)(block: => Unit)(implicit sourceInfo: SourceInfo, compileOptions: CompileOptions): WhenContext = { // scalastyle:ignore line.size.limit
+  def apply(cond: => Bool)(block: => Any)(implicit sourceInfo: SourceInfo, compileOptions: CompileOptions): WhenContext = { // scalastyle:ignore line.size.limit
     new WhenContext(sourceInfo, Some(() => cond), block)
   }
 }
@@ -43,7 +43,7 @@ object when {  // scalastyle:ignore object.name
   *  succeeding elsewhen or otherwise; therefore, this information is
   *  added by preprocessing the command queue.
   */
-final class WhenContext(sourceInfo: SourceInfo, cond: Option[() => Bool], block: => Unit, firrtlDepth: Int = 0) {
+final class WhenContext(sourceInfo: SourceInfo, cond: Option[() => Bool], block: => Any, firrtlDepth: Int = 0) {
 
   /** This block of logic gets executed if above conditions have been
     * false and this condition is true. The lazy argument pattern
@@ -51,7 +51,7 @@ final class WhenContext(sourceInfo: SourceInfo, cond: Option[() => Bool], block:
     * declaration and assignment of the Bool node of the predicate in
     * the correct place.
     */
-  def elsewhen (elseCond: => Bool)(block: => Unit)(implicit sourceInfo: SourceInfo, compileOptions: CompileOptions): WhenContext = { // scalastyle:ignore line.size.limit
+  def elsewhen (elseCond: => Bool)(block: => Any)(implicit sourceInfo: SourceInfo, compileOptions: CompileOptions): WhenContext = { // scalastyle:ignore line.size.limit
     new WhenContext(sourceInfo, Some(() => elseCond), block, firrtlDepth + 1)
   }
 
@@ -62,7 +62,7 @@ final class WhenContext(sourceInfo: SourceInfo, cond: Option[() => Bool], block:
     * assignment of the Bool node of the predicate in the correct
     * place.
     */
-  def otherwise(block: => Unit)(implicit sourceInfo: SourceInfo, compileOptions: CompileOptions): Unit =
+  def otherwise(block: => Any)(implicit sourceInfo: SourceInfo, compileOptions: CompileOptions): Unit =
     new WhenContext(sourceInfo, None, block, firrtlDepth + 1)
 
   /*