Use ChiselStage in Tests

This migrates the tests to Chisel 3.4/FIRRTL 1.4. This primarily
involves removing usages of deprecated methods including:

- Remove usages of Driver
- Use ChiselStage methods instead of BackendCompilationUtilities
  methods
- Use Dependency API for custom transforms
- Use extractCause to unpack StackError

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

1 files changed, 30 insertions, 13 deletions

diff --git a/src/test/scala/chiselTests/MultiAssign.scala b/src/test/scala/chiselTests/MultiAssign.scala
index 8da5bc42..b232bd75 100644
--- a/src/test/scala/chiselTests/MultiAssign.scala
+++ b/src/test/scala/chiselTests/MultiAssign.scala
@@ -4,6 +4,7 @@ package chiselTests
 
 import chisel3._
 import chisel3.testers.BasicTester
+import chisel3.stage.ChiselStage
 import chisel3.util._
 
 class LastAssignTester() extends BasicTester {
@@ -30,36 +31,52 @@ class MultiAssignSpec extends ChiselFlatSpec {
   }
 }
 
-class IllegalAssignSpec extends ChiselFlatSpec {
+class IllegalAssignSpec extends ChiselFlatSpec with Utils {
   "Reassignments to literals" should "be disallowed" in {
     intercept[chisel3.internal.ChiselException] {
-      elaborate{ new BasicTester {
-        15.U := 7.U
-      }}
+      extractCause[ChiselException] {
+        ChiselStage.elaborate{
+          new BasicTester {
+            15.U := 7.U
+          }
+        }
+      }
     }
   }
 
   "Reassignments to ops" should "be disallowed" in {
     intercept[chisel3.internal.ChiselException] {
-      elaborate{ new BasicTester {
-        (15.U + 1.U) := 7.U
-      }}
+      extractCause[ChiselException] {
+        ChiselStage.elaborate{
+          new BasicTester {
+            (15.U + 1.U) := 7.U
+          }
+        }
+      }
     }
   }
 
   "Reassignments to bit slices" should "be disallowed" in {
     intercept[chisel3.internal.ChiselException] {
-      elaborate{ new BasicTester {
-        (15.U)(1, 0) := 7.U
-      }}
+      extractCause[ChiselException] {
+        ChiselStage.elaborate{
+          new BasicTester {
+            (15.U)(1, 0) := 7.U
+          }
+        }
+      }
     }
   }
 
   "Bulk-connecting two read-only nodes" should "be disallowed" in {
     intercept[chisel3.internal.ChiselException] {
-      elaborate{ new BasicTester {
-        (15.U + 1.U) <> 7.U
-      }}
+      extractCause[ChiselException] {
+        ChiselStage.elaborate{
+          new BasicTester {
+            (15.U + 1.U) <> 7.U
+          }
+        }
+      }
     }
   }
 }