Add ChiselPhase, Stop writing files in ChiselStage$ methods, Expand ChiselStage$ helpers (#1566)

* Add ChiselPhase

* Use ChiselPhase in ChiselStage, remove targets

Switch from a one-off PhaseManager inside ChiselStage to actually
using the newly added ChiselPhase. This removes the targets
method (and API) from ChiselStage.

* Stop writing to files in ChiselStage$ methods

Change the ChiselStage companion object methods, elaborate and
convert, to not write files. Under the hood, these are switched from
using ChiselStage (which, like all phases, will write files) to using
ChiselPhase.

* Test that ChiselStage$ methods write no files

Modify existing ChiselStage object method tests to check that no files
are written.

* Expand ChiselStage$ API with more helpers

This adds additional methods to the ChiselStage object for going
directly from a Chisel module to a string including: CHIRRTL, high
FIRRTL IR, Verilog, and SystemVerilog.

Differing from their ChiselStage class counterparts, these take no
arguments other than the module and write no files.

* Add tests of new ChiselStage$ helper methods

* Use ChiselStage object in tests

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

1 files changed, 2 insertions, 2 deletions

diff --git a/src/test/scala/chiselTests/ResetSpec.scala b/src/test/scala/chiselTests/ResetSpec.scala
index 9d67637d..84d3985b 100644
--- a/src/test/scala/chiselTests/ResetSpec.scala
+++ b/src/test/scala/chiselTests/ResetSpec.scala
@@ -73,14 +73,14 @@ class ResetSpec extends ChiselFlatSpec with Utils {
   behavior of "Users"
 
   they should "be able to force implicit reset to be synchronous" in {
-    val fir = (new ChiselStage).emitChirrtl(new MultiIOModule with RequireSyncReset {
+    val fir = ChiselStage.emitChirrtl(new MultiIOModule with RequireSyncReset {
       reset shouldBe a [Bool]
     })
     fir should include ("input reset : UInt<1>")
   }
 
   they should "be able to force implicit reset to be asynchronous" in {
-    val fir = (new ChiselStage).emitChirrtl(new MultiIOModule with RequireAsyncReset {
+    val fir = ChiselStage.emitChirrtl(new MultiIOModule with RequireAsyncReset {
       reset shouldBe an [AsyncReset]
     })
     fir should include ("input reset : AsyncReset")