Add FirrtlStage, make Driver compatibility layer

This adds FirrtlStage, a reimplementation of the original FIRRTL
Driver as a Stage. This updates the original firrtl.options package to
implement FirrtlStage (namely, TransformLike is added) along with
FirrtlMain. Finally, the original FIRRTL Driver is converted to a
compatibility wrapper around FirrtlStage.

For background, Stage and Phase form the basis of the Chisel/FIRRTL
Hardware Compiler Framework (HCF). A Phase is a class that performs a
mathematical transformation on an AnnotationSeq (in effect, a
generalization of a FIRRTL transform). Curtly, a Stage is a Phase that
also provides a user interface for generating annotations. By their
construction, Phases are designed to be composed sequentially into a
transformation pipeline.

This modifies the existing options package (which provides
Stage/Phase) to build out a type hierarchy around Stage/Phase. This
adds TransformLike[A] which implements a mathematical transformation
over some type A. Additionally, and as an interface between different
TransformLikes, this adds Translator[A, B] which extends
TransformLike[A], but does an internal transformation over type B.
This is used to interface Phases with the existing FIRRTL compiler.

This adds a runTransform method to Phase that, like
Transform.runTransform, will automatically detect deleted Annotations
and generate DeletedAnnotations.

The new FirrtlStage, a reimplementation of FIRRTL's Driver, is added
as a Stage composed of the following Phases:

  1. AddDefaults - add default annotations
  2. AddImplicitEmitter - adds an implicit emitter derived from the
     compiler
  3. Checks - sanity check the AnnotationSeq
  4. AddCircuit - convert FIRRTL input files/sources to circuits
  5. AddImplicitOutputFile - add a default output file
  6. Compiler - run the FIRRTL compiler
  7. WriteEmitted - write any emitted modules/circuits to files

The Driver is converted to a compatibility layer that replicates old
Driver behavior. This is implemented by first using new toAnnotation
methods for CommonOptions and FirrtlExecutionOptions that enable
AnnotationSeq generation. Second, the generated AnnotationSeq is
preprocessed and sent to FirrtlStage. The resulting Phase order is
then:

  1. AddImplicitAnnotationFile - adds a default annotation file
  2. AddImplicitFirrtlFile - adds a default FIRRTL file using top name
  3. AddImplicitOutputFile - adds an output file from top name
  4. AddImplicitEmitter - adds a default emitter derived from a
     compiler and any split modules command line option
  5. FirrtlStage - the aforementioned new FirrtlStage

Finally, the output AnnotationSeq is then viewed as a
FirrtlExecutionResult. This compatibility layer enables uninterrupted
usage of old Driver infrastructure, e.g., FirrtlExecutionOptions and
CommonOptions can still be mutated directly and used to run the
Driver.

This results in differing behavior between the new FirrtlStage and the
old Driver, specifically:

  - FirrtlStage makes a clear delineation between a "compiler" and an
    "emitter". These are defined using separate options. A compiler is
    "-X/--compiler", while an emitter is one of "-E/--emit-circuit" or
    "-e/--emit-modules".
  - Related to the above, the "-fsm/--split-modules" has been removed
    from the FirrtlStage. This option is confusing once an implicit
    emitter is removed. It is also unclear how this should be handled
    once the user can specify multiple emitters, e.g., which emitter
    should "--split-modules" apply to?
  - WriteOutputAnnotations will, by default, not write
    DeletedAnnotations to the output file.
  - The old top name ("-tn/--top-name") option has been removed from
    FirrtlStage. This option is really a means to communicate what
    input and output files are as opposed to anything associated with
    the circuit name. This option is preserved for the Driver
    compatibility layer.

Additionally, this changes existing transform scheduling to work for
emitters (which subclass Transform). Previously, one emitter was
explicitly scheduled at the end of all transforms for a given
compiler. Additional emitters could be added, but they would be
scheduled as transforms. This fixes this to rely on transform
scheduling for all emitters. In slightly more detail:

  1. The explicit emitter is removed from Compiler.compile
  2. An explicit emitter is added to Compiler.compileAndEmit
  3. Compiler.mergeTransforms will schedule emitters as late as
     possible, i.e., all emitters will occur after transforms that
     output their input form.
  4. All AddImplicitEmitter phases (DriverCompatibility and normal)
     will add RunFirrtlTransformAnnotations to add implicit emitters

The FIRRTL fat jar utilities are changed to point at FirrtlStage and not
at the Driver. This has backwards incompatibility issues for users
that are using the utilities directly, e.g., Rocket Chip.

The Logger has been updated with methods for setting options based on
an AnnotationSeq. This migrates the Logger to use AnnotationSeq as
input parameters, e.g., for makeScope. Old-style methods are left in
place and deprecated. However, the Logger is not itself a Stage.
The options of Logger Annotations are included in the base Shell and
Stage is updated to wrap its Phases in a Logger scope.

Additionally, this changes any code that does option parsing to always
prepend an annotation as opposed to appending an annotation. This is
faster, but standardizing on this has implications for dealing with
the parallel compilation annotation ordering.

A Shell will now put the initial annotations first (in the order the
user specified) and then place all annotations generating from parsing
after that. This adds a test case to verify this behavior.

Discovered custom transforms (via `RunFirrtlTransformAnnotation`s) are
discovered by the compiler phase in a user-specified order, but are
stored in reverse order to more efficiently prepend (as opposed to
append) to a list. This now reverses the transform order before
execution to preserve backwards compatibility of custom transform
ordering.

The Compiler phase also generates one deleted annotation for each
`RunFirrtlTransformAnnotation`. These are also reversed.

Miscellaneous small changes:

  - Split main method of Stage into StageMain class
  - Only mix in HasScoptOptions into Annotation companion objects (h/t
    @jackkoenig)
  - Store Compiler in CompilerAnnotation
  - CompilerNameAnnotation -> CompilerAnnotation
  - Make Emitter abstract in outputSuffix (move out of FirrtlOptions)
  - Add DriverCompatibility.AddImplicitOutputFile that will add an
    output file annotation based on the presence of a
    TopNameAnnotation. This is important for compatibility with the
    old Driver.
  - Cleanup Scaladoc
  - Refactor CircuitOption to be abstract in "toCircuit" that converts
    the option to a FirrtlCircuitAnnotation. This allows more of the
    conversion steps to be moved out of AddCircuit and into the actual
    annotation.
  - Add WriteDeletedAnnotation to module WriteOutputAnnotations
  - A method for accessing a FirrtlExecutionResultView is exposed in
    FIRRTL's DriverCompatibilityLayer
  - Using "--top-name/-tn" or "--split-modules/-fsm" with FirrtlStage
    generates an error indicating that this option is no longer
    supported
  - Using FirrtlStage without at least one emitter will generate a
    warning
  - Use vals for emitter in Compiler subclasses (these are used to
    build RunFirrtlTransformAnnotations and the object should be
    stable for comparisons)
  - Fixes to tests that use LowTransformSpec instead of
    MiddleTransformSpec. (SimpleTransformSpec is dumb and won't
    schedule transforms correctly. If you rely on an emitter, you need
    to use the right transform spec to test your transform if you're
    relying on an emitter.)

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

1 files changed, 33 insertions, 97 deletions

diff --git a/src/main/scala/firrtl/Driver.scala b/src/main/scala/firrtl/Driver.scala
index e96c3c5b..f23be6f5 100644
--- a/src/main/scala/firrtl/Driver.scala
+++ b/src/main/scala/firrtl/Driver.scala
@@ -4,11 +4,10 @@ package firrtl
 
 import scala.collection._
 import scala.io.Source
-import scala.sys.process.{BasicIO, ProcessLogger, stringSeqToProcess}
 import scala.util.{Failure, Success, Try}
 import scala.util.control.ControlThrowable
 import java.io.{File, FileNotFoundException}
-
+import scala.sys.process.{BasicIO, ProcessLogger, stringSeqToProcess}
 import net.jcazevedo.moultingyaml._
 import logger.Logger
 import Parser.{IgnoreInfo, InfoMode}
@@ -17,6 +16,10 @@ import firrtl.annotations.AnnotationYamlProtocol._
 import firrtl.passes.{PassException, PassExceptions}
 import firrtl.transforms._
 import firrtl.Utils.throwInternalError
+import firrtl.stage.{FirrtlExecutionResultView, FirrtlStage}
+import firrtl.stage.phases.DriverCompatibility
+import firrtl.options.{StageUtils, Phase}
+import firrtl.options.Viewer.view
 
 
 /**
@@ -40,30 +43,22 @@ import firrtl.Utils.throwInternalError
   * @see firrtlTests/DriverSpec.scala in the test directory for a lot more examples
   * @see [[CompilerUtils.mergeTransforms]] to see how customTransformations are inserted
   */
-
+@deprecated("Use firrtl.stage.FirrtlStage", "1.2")
 object Driver {
   /** Print a warning message
     *
     * @param message error message
     */
-  //scalastyle:off regex
-  def dramaticWarning(message: String): Unit = {
-    println(Console.YELLOW + "-"*78)
-    println(s"Warning: $message")
-    println("-"*78 + Console.RESET)
-  }
+  @deprecated("Use firrtl.options.StageUtils.dramaticWarning", "1.2")
+  def dramaticWarning(message: String): Unit = StageUtils.dramaticWarning(message)
 
   /**
     * print the message in red
     *
     * @param message error message
     */
-  //scalastyle:off regex
-  def dramaticError(message: String): Unit = {
-    println(Console.RED + "-"*78)
-    println(s"Error: $message")
-    println("-"*78 + Console.RESET)
-  }
+  @deprecated("Use firrtl.options.StageUtils.dramaticWarning", "1.2")
+  def dramaticError(message: String): Unit = StageUtils.dramaticError(message)
 
   /** Load annotation file based on options
     * @param optionsManager use optionsManager config to load annotation file if it exists
@@ -107,7 +102,7 @@ object Driver {
     if (firrtlConfig.annotationFileNameOverride.nonEmpty) {
       val msg = "annotationFileNameOverride is deprecated! " +
                 "Use annotationFileNames"
-      Driver.dramaticWarning(msg)
+      dramaticWarning(msg)
     } else if (usingImplicitAnnoFile) {
       val msg = "Implicit .anno file from top-name is deprecated!\n" +
              (" "*9) + "Use explicit -faf option or annotationFileNames"
@@ -159,7 +154,7 @@ object Driver {
     }
 
   // Useful for handling erros in the options
-  case class OptionsException(msg: String) extends Exception(msg)
+  case class OptionsException(message: String) extends Exception(message)
 
   /** Get the Circuit from the compile options
     *
@@ -216,77 +211,25 @@ object Driver {
     * @return a FirrtlExecutionResult indicating success or failure, provide access to emitted data on success
     *         for downstream tools as desired
     */
-  //scalastyle:off cyclomatic.complexity method.length
   def execute(optionsManager: ExecutionOptionsManager with HasFirrtlOptions): FirrtlExecutionResult = {
-    def firrtlConfig = optionsManager.firrtlOptions
-
-    Logger.makeScope(optionsManager) {
-      // Wrap compilation in a try/catch to present Scala MatchErrors in a more user-friendly format.
-      val finalState = try {
-        val circuit = getCircuit(optionsManager) match {
-          case Success(c) => c
-          case Failure(OptionsException(msg)) =>
-            dramaticError(msg)
-            return FirrtlExecutionFailure(msg)
-          case Failure(e) => throw e
-        }
+    StageUtils.dramaticWarning("firrtl.Driver is deprecated since 1.2!\nPlease switch to firrtl.stage.FirrtlStage")
 
-        val annos = getAnnotations(optionsManager)
+    val annos = optionsManager.firrtlOptions.toAnnotations ++ optionsManager.commonOptions.toAnnotations
 
-        // Does this need to be before calling compiler?
-        optionsManager.makeTargetDir()
+    val phases: Seq[Phase] = Seq(
+      new DriverCompatibility.AddImplicitAnnotationFile,
+      new DriverCompatibility.AddImplicitFirrtlFile,
+      new DriverCompatibility.AddImplicitOutputFile,
+      new DriverCompatibility.AddImplicitEmitter,
+      new FirrtlStage )
 
-        firrtlConfig.compiler.compile(
-          CircuitState(circuit, ChirrtlForm, annos),
-          firrtlConfig.customTransforms
-        )
-      }
-      catch {
-        // Rethrow the exceptions which are expected or due to the runtime environment (out of memory, stack overflow)
-        case p: ControlThrowable => throw p
-        case p: PassException    => throw p
-        case p: PassExceptions   => throw p
-        case p: FIRRTLException  => throw p
-        // Propagate exceptions from custom transforms
-        case CustomTransformException(cause) => throw cause
-        // Treat remaining exceptions as internal errors.
-        case e: Exception => throwInternalError(exception = Some(e))
-      }
-
-      // Do emission
-      // Note: Single emission target assumption is baked in here
-      // Note: FirrtlExecutionSuccess emitted is only used if we're emitting the whole Circuit
-      val emittedRes = firrtlConfig.getOutputConfig(optionsManager) match {
-        case SingleFile(filename) =>
-          val emitted = finalState.getEmittedCircuit
-          val outputFile = new java.io.PrintWriter(filename)
-          outputFile.write(emitted.value)
-          outputFile.close()
-          emitted.value
-        case OneFilePerModule(dirName) =>
-          val emittedModules = finalState.emittedComponents collect { case x: EmittedModule => x }
-          if (emittedModules.isEmpty) throwInternalError() // There should be something
-          emittedModules.foreach { module =>
-            val filename = optionsManager.getBuildFileName(firrtlConfig.outputSuffix, s"$dirName/${module.name}")
-            val outputFile = new java.io.PrintWriter(filename)
-            outputFile.write(module.value)
-            outputFile.close()
-          }
-          "" // Should we return something different here?
-      }
-
-      // If set, emit final annotations to a file
-      optionsManager.firrtlOptions.outputAnnotationFileName match {
-        case "" =>
-        case file =>
-          val filename = optionsManager.getBuildFileName("anno.json", file)
-          val outputFile = new java.io.PrintWriter(filename)
-          outputFile.write(JsonProtocol.serialize(finalState.annotations))
-          outputFile.close()
-      }
-
-      FirrtlExecutionSuccess(firrtlConfig.compilerName, emittedRes, finalState)
+    val annosx = try {
+      phases.foldLeft(annos)( (a, p) => p.runTransform(a) )
+    } catch {
+      case e: firrtl.options.OptionsException => return FirrtlExecutionFailure(e.message)
     }
+
+    view[FirrtlExecutionResult](annosx)
   }
 
   /**
@@ -321,23 +264,16 @@ object Driver {
 }
 
 object FileUtils {
-  /**
-    * recursive create directory and all parents
-    *
+
+  /** Create a directory if it doesn't exist
     * @param directoryName a directory string with one or more levels
-    * @return
+    * @return true if the directory exists or if it was successfully created
     */
   def makeDirectory(directoryName: String): Boolean = {
-    val dirFile = new java.io.File(directoryName)
+    val dirFile = new File(directoryName)
     if(dirFile.exists()) {
-      if(dirFile.isDirectory) {
-        true
-      }
-      else {
-        false
-      }
-    }
-    else {
+      dirFile.isDirectory
+    } else {
       dirFile.mkdirs()
     }
   }
@@ -361,7 +297,7 @@ object FileUtils {
     if(file.getPath.split("/").last.isEmpty ||
       file.getAbsolutePath == "/" ||
       file.getPath.startsWith("/")) {
-      Driver.dramaticError(s"delete directory ${file.getPath} will not delete absolute paths")
+      StageUtils.dramaticError(s"delete directory ${file.getPath} will not delete absolute paths")
       false
     }
     else {