Add option to treat warnings as errors (backport #2676) (#2677)

* Add option to treat warnings as errors (#2676)

Add --warnings-as-errors option

(cherry picked from commit 498946663726955c380a1e420f5d7b9630000aad)

# Conflicts:
#	core/src/main/scala/chisel3/experimental/hierarchy/Definition.scala
#	core/src/main/scala/chisel3/internal/Builder.scala
#	src/main/scala/chisel3/aop/injecting/InjectingAspect.scala
#	src/main/scala/chisel3/stage/ChiselOptions.scala
#	src/main/scala/chisel3/stage/package.scala
#	src/main/scala/chisel3/stage/phases/Elaborate.scala

* Resolve backport conflicts

Co-authored-by: Zachary Yedidia <zyedidia@gmail.com>
Co-authored-by: Jack Koenig <koenig@sifive.com>

3 files changed, 12 insertions, 7 deletions

diff --git a/core/src/main/scala/chisel3/experimental/hierarchy/Definition.scala b/core/src/main/scala/chisel3/experimental/hierarchy/Definition.scala
index 36bf6f87..99eacc7d 100644
--- a/core/src/main/scala/chisel3/experimental/hierarchy/Definition.scala
+++ b/core/src/main/scala/chisel3/experimental/hierarchy/Definition.scala
@@ -103,7 +103,7 @@ object Definition extends SourceInfoDoc {
   ): Definition[T] = {
     val dynamicContext = {
       val context = Builder.captureContext()
-      new DynamicContext(Nil, context.throwOnFirstError, context.warnReflectiveNaming)
+      new DynamicContext(Nil, context.throwOnFirstError, context.warnReflectiveNaming, context.warningsAsErrors)
     }
     Builder.globalNamespace.copyTo(dynamicContext.globalNamespace)
     dynamicContext.inDefinition = true
diff --git a/core/src/main/scala/chisel3/internal/Builder.scala b/core/src/main/scala/chisel3/internal/Builder.scala
index b2c98309..75d08f92 100644
--- a/core/src/main/scala/chisel3/internal/Builder.scala
+++ b/core/src/main/scala/chisel3/internal/Builder.scala
@@ -244,7 +244,8 @@ private[chisel3] trait HasId extends InstanceId {
       // These accesses occur after Chisel elaboration so we cannot use the normal
       // Builder.deprecated mechanism, we have to create our own one off ErrorLog and print the
       // warning right away.
-      val errors = new ErrorLog
+      // It's especially bad because --warnings-as-errors does not work with these warnings
+      val errors = new ErrorLog(false)
       val logger = new _root_.logger.Logger(this.getClass.getName)
       val msg = "Accessing the .instanceName or .toTarget of non-hardware Data is deprecated. " +
         "This will become an error in Chisel 3.6."
@@ -376,7 +377,8 @@ private[chisel3] class ChiselContext() {
 private[chisel3] class DynamicContext(
   val annotationSeq:        AnnotationSeq,
   val throwOnFirstError:    Boolean,
-  val warnReflectiveNaming: Boolean) {
+  val warnReflectiveNaming: Boolean,
+  val warningsAsErrors:     Boolean) {
   val importDefinitionAnnos = annotationSeq.collect { case a: ImportDefinitionAnnotation[_] => a }
 
   // Map holding the actual names of extModules
@@ -433,7 +435,7 @@ private[chisel3] class DynamicContext(
   var whenStack:            List[WhenContext] = Nil
   var currentClock:         Option[Clock] = None
   var currentReset:         Option[Reset] = None
-  val errors = new ErrorLog
+  val errors = new ErrorLog(warningsAsErrors)
   val namingStack = new NamingStack
 
   // Used to indicate if this is the top-level module of full elaboration, or from a Definition
diff --git a/core/src/main/scala/chisel3/internal/Error.scala b/core/src/main/scala/chisel3/internal/Error.scala
index 98db7109..da968d2a 100644
--- a/core/src/main/scala/chisel3/internal/Error.scala
+++ b/core/src/main/scala/chisel3/internal/Error.scala
@@ -176,7 +176,7 @@ private[chisel3] object ErrorLog {
   val errTag = s"[${Console.RED}error${Console.RESET}]"
 }
 
-private[chisel3] class ErrorLog {
+private[chisel3] class ErrorLog(warningsAsErrors: Boolean) {
   def getLoc(loc: Option[StackTraceElement]): String = {
     loc match {
       case Some(elt: StackTraceElement) => s"${elt.getFileName}:${elt.getLineNumber}"
@@ -190,17 +190,20 @@ private[chisel3] class ErrorLog {
     errors += (((m, getLoc(loc)), new Error(m, loc)))
   }
 
+  private def warn(m: => String, loc: Option[StackTraceElement]): LogEntry =
+    if (warningsAsErrors) new Error(m, loc) else new Warning(m, loc)
+
   /** Log a warning message */
   def warning(m: => String): Unit = {
     val loc = getUserLineNumber
-    errors += (((m, getLoc(loc)), new Warning(m, loc)))
+    errors += (((m, getLoc(loc)), warn(m, loc)))
   }
 
   /** Log a warning message without a source locator. This is used when the
     * locator wouldn't be helpful (e.g., due to lazy values).
     */
   def warningNoLoc(m: => String): Unit =
-    errors += (((m, ""), new Warning(m, None)))
+    errors += (((m, ""), warn(m, None)))
 
   /** Emit an informational message */
   @deprecated("This method will be removed in 3.5", "3.4")