Stop Emitting BlackBoxResourceAnno (#1954)

* Change HasBlackBoxResource to Resolve Resources

Change HasBlackBoxResource to resolve resources immediately and emit
BlackBoxInlineAnno instead of a BlackBoxResourceAnno.  This removes the
need for a FIRRTL compiler to grok the Java Resource API in order to
handle BlackBoxResourceAnno.

Emit BlackBoxInlineAnno from HasExtModuleResource instead of
BlackBoxResourceAnno.

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

4 files changed, 66 insertions, 5 deletions

diff --git a/src/main/scala/chisel3/util/BlackBoxUtils.scala b/src/main/scala/chisel3/util/BlackBoxUtils.scala
index 3cd704b3..443d7f3e 100644
--- a/src/main/scala/chisel3/util/BlackBoxUtils.scala
+++ b/src/main/scala/chisel3/util/BlackBoxUtils.scala
@@ -4,12 +4,39 @@ package chisel3.util
 
 import chisel3._
 import chisel3.experimental.{ChiselAnnotation, RunFirrtlTransform}
-import firrtl.transforms.{BlackBoxPathAnno, BlackBoxResourceAnno, BlackBoxInlineAnno, BlackBoxSourceHelper}
+import firrtl.transforms.{BlackBoxPathAnno, BlackBoxResourceAnno, BlackBoxInlineAnno, BlackBoxSourceHelper,
+  BlackBoxNotFoundException}
+import firrtl.annotations.ModuleName
+import logger.LazyLogging
+
+private[util] object BlackBoxHelpers {
+
+  implicit class BlackBoxInlineAnnoHelpers(anno: BlackBoxInlineAnno.type) extends LazyLogging {
+    /** Generate a BlackBoxInlineAnno from a Java Resource and a module name. */
+    def fromResource(resourceName: String, moduleName: ModuleName) = try {
+      val blackBoxFile = os.resource / os.RelPath(resourceName.dropWhile(_ == '/'))
+      val contents = os.read(blackBoxFile)
+      if (contents.size > BigInt(2).pow(20)) {
+        val message =
+          s"Black box resource $resourceName, which will be converted to an inline annotation, is greater than 1 MiB." +
+            "This may affect compiler performance. Consider including this resource via a black box path."
+        logger.warn(message)
+      }
+      BlackBoxInlineAnno(moduleName, blackBoxFile.last, contents)
+    } catch {
+      case e: os.ResourceNotFoundException =>
+        throw new BlackBoxNotFoundException(resourceName, e.getMessage)
+    }
+  }
+}
+
+import BlackBoxHelpers._
 
 trait HasBlackBoxResource extends BlackBox {
   self: BlackBox =>
 
-  /** Copies a resource file to the target directory
+  /** Copies a Java resource containing some text into the output directory. This is typically used to copy a Verilog file
+    * to the final output directory, but may be used to copy any Java resource (e.g., a C++ testbench).
     *
     * Resource files are located in project_root/src/main/resources/.
     * Example of adding the resource file project_root/src/main/resources/blackbox.v:
@@ -19,7 +46,7 @@ trait HasBlackBoxResource extends BlackBox {
     */
   def addResource(blackBoxResource: String): Unit = {
     val anno = new ChiselAnnotation with RunFirrtlTransform {
-      def toFirrtl = BlackBoxResourceAnno(self.toNamed, blackBoxResource)
+      def toFirrtl = BlackBoxInlineAnno.fromResource(blackBoxResource, self.toNamed)
       def transformClass = classOf[BlackBoxSourceHelper]
     }
     chisel3.experimental.annotate(anno)
diff --git a/src/main/scala/chisel3/util/ExtModuleUtils.scala b/src/main/scala/chisel3/util/ExtModuleUtils.scala
index 831639be..62f384bc 100644
--- a/src/main/scala/chisel3/util/ExtModuleUtils.scala
+++ b/src/main/scala/chisel3/util/ExtModuleUtils.scala
@@ -3,7 +3,10 @@
 package chisel3.util
 
 import chisel3.experimental.{ChiselAnnotation, ExtModule, RunFirrtlTransform}
-import firrtl.transforms.{BlackBoxPathAnno, BlackBoxResourceAnno, BlackBoxInlineAnno, BlackBoxSourceHelper}
+import firrtl.transforms.{BlackBoxPathAnno, BlackBoxResourceAnno, BlackBoxInlineAnno, BlackBoxSourceHelper,
+  BlackBoxNotFoundException}
+
+import BlackBoxHelpers._
 
 trait HasExtModuleResource extends ExtModule {
   self: ExtModule =>
@@ -18,7 +21,7 @@ trait HasExtModuleResource extends ExtModule {
     */
   def addResource(blackBoxResource: String): Unit = {
     val anno = new ChiselAnnotation with RunFirrtlTransform {
-      def toFirrtl = BlackBoxResourceAnno(self.toNamed, blackBoxResource)
+      def toFirrtl = BlackBoxInlineAnno.fromResource(blackBoxResource, self.toNamed)
       def transformClass = classOf[BlackBoxSourceHelper]
     }
     chisel3.experimental.annotate(anno)
diff --git a/src/test/scala/chiselTests/BlackBoxImpl.scala b/src/test/scala/chiselTests/BlackBoxImpl.scala
index f8e16ad7..a9a6fa29 100644
--- a/src/test/scala/chiselTests/BlackBoxImpl.scala
+++ b/src/test/scala/chiselTests/BlackBoxImpl.scala
@@ -8,6 +8,7 @@ import chisel3._
 import chisel3.util.{HasBlackBoxInline, HasBlackBoxResource, HasBlackBoxPath}
 import chisel3.stage.{ChiselGeneratorAnnotation, ChiselStage}
 import firrtl.FirrtlExecutionSuccess
+import firrtl.transforms.BlackBoxNotFoundException
 import org.scalacheck.Test.Failed
 import org.scalatest.Succeeded
 import org.scalatest.freespec.AnyFreeSpec
@@ -88,6 +89,15 @@ class UsesBlackBoxMinusViaPath extends Module {
   io.out := mod0.io.out
 }
 
+class BlackBoxResourceNotFound extends HasBlackBoxResource {
+  val io = IO(new Bundle{})
+  addResource("/missing.resource")
+}
+
+class UsesMissingBlackBoxResource extends RawModule {
+  val foo = Module(new BlackBoxResourceNotFound)
+}
+
 class BlackBoxImplSpec extends AnyFreeSpec with Matchers {
   val targetDir = "test_run_dir"
   val stage = new ChiselStage
@@ -114,5 +124,10 @@ class BlackBoxImplSpec extends AnyFreeSpec with Matchers {
       verilogOutput.delete()
       Succeeded
     }
+    "Resource files that do not exist produce Chisel errors" in {
+      assertThrows[BlackBoxNotFoundException]{
+        ChiselStage.emitChirrtl(new UsesMissingBlackBoxResource)
+      }
+    }
   }
 }
diff --git a/src/test/scala/chiselTests/ExtModuleImpl.scala b/src/test/scala/chiselTests/ExtModuleImpl.scala
index f71a1335..e0a76201 100644
--- a/src/test/scala/chiselTests/ExtModuleImpl.scala
+++ b/src/test/scala/chiselTests/ExtModuleImpl.scala
@@ -11,6 +11,7 @@ import chisel3.util.{HasExtModuleInline, HasExtModulePath, HasExtModuleResource}
 import firrtl.FirrtlExecutionSuccess
 import firrtl.options.TargetDirAnnotation
 import firrtl.stage.FirrtlCircuitAnnotation
+import firrtl.transforms.BlackBoxNotFoundException
 import org.scalacheck.Test.Failed
 import org.scalatest.{FreeSpec, Matchers, Succeeded}
 
@@ -92,6 +93,15 @@ class UsesExtModuleMinusViaPath extends Module {
   io.out := mod0.io.out
 }
 
+class ExtModuleResourceNotFound extends HasExtModuleResource {
+  val io = IO(new Bundle{})
+  addResource("/missing.resource")
+}
+
+class UsesMissingExtModuleResource extends RawModule {
+  val foo = Module(new ExtModuleResourceNotFound)
+}
+
 class ExtModuleImplSpec extends FreeSpec with Matchers {
   "ExtModule can have verilator source implementation" - {
 
@@ -137,5 +147,11 @@ class ExtModuleImplSpec extends FreeSpec with Matchers {
       verilogOutput.exists() should be(true)
       verilogOutput.delete()
     }
+
+    "Resource files that do not exist produce Chisel errors" in {
+      assertThrows[BlackBoxNotFoundException]{
+        ChiselStage.emitChirrtl(new UsesMissingExtModuleResource)
+      }
+    }
   }
 }