MatchError in code gen emitting annotation with Ident arg

[retronym]

I noticed this when trying to upgrade the Dotty version used in scala/compiler-benchmark

I was upgrading to 0.8.0-RC1.

[error] Ident(SampleTime) (of class dotty.tools.dotc.ast.Trees$Ident)
scala.MatchError: Ident(SingleShotTime) (of class dotty.tools.dotc.ast.Trees$Ident)
	at dotty.tools.backend.jvm.DottyBackendInterface.emitArgument(DottyBackendInterface.scala:246)
	at dotty.tools.backend.jvm.DottyBackendInterface.emitArgument$$anonfun$3(DottyBackendInterface.scala:291)
	at scala.compat.java8.JProcedure1.apply(JProcedure1.java:18)
	at scala.compat.java8.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:389)
	at dotty.tools.backend.jvm.DottyBackendInterface.emitArgument(DottyBackendInterface.scala:292)
	at dotty.tools.backend.jvm.DottyBackendInterface.emitAssocs$$anonfun$2(DottyBackendInterface.scala:328)
	at scala.compat.java8.JProcedure1.apply(JProcedure1.java:18)
	at scala.compat.java8.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.TraversableLike$WithFilter.$anonfun$foreach$1(TraversableLike.scala:789)
	at scala.collection.immutable.List.foreach(List.scala:389)
	at scala.collection.TraversableLike$WithFilter.foreach(TraversableLike.scala:788)
	at dotty.tools.backend.jvm.DottyBackendInterface.emitAssocs(DottyBackendInterface.scala:

A workaround is use Select-s rather than Ident-s in runtime-retained annotation arguments.

diff --git a/compilation/src/main/dotc/scala/tools/benchmark/BenchmarkDriver.scala b/compilation/src/main/dotc/scala/tools/benchmark/BenchmarkDriver.scala
index 632210d..2793d04 100644
--- a/compilation/src/main/dotc/scala/tools/benchmark/BenchmarkDriver.scala
+++ b/compilation/src/main/dotc/scala/tools/benchmark/BenchmarkDriver.scala
@@ -13,7 +13,7 @@ trait BenchmarkDriver extends BaseBenchmarkDriver {
                      depsClasspath.mkString(File.pathSeparator))
     }
     ctx.setSetting(ctx.settings.migration, false)
-    ctx.setSetting(ctx.settings.d, tempDir.getAbsolutePath)
+    ctx.setSetting(ctx.settings.outputDir, tempDir.getAbsolutePath)
     ctx.setSetting(ctx.settings.language, List("Scala2"))
     val compiler = new dotty.tools.dotc.Compiler
     val reporter = dotty.tools.dotc.Bench.doCompile(compiler, allArgs)
diff --git a/compilation/src/main/scala/scala/tools/nsc/HotSbtBenchmark.scala b/compilation/src/main/scala/scala/tools/nsc/HotSbtBenchmark.scala
index 102cafb..ba77ba1 100644
--- a/compilation/src/main/scala/scala/tools/nsc/HotSbtBenchmark.scala
+++ b/compilation/src/main/scala/scala/tools/nsc/HotSbtBenchmark.scala
@@ -4,11 +4,11 @@ import java.io._
 import java.nio.file._
 import java.util.concurrent.TimeUnit
 
-import org.openjdk.jmh.annotations.Mode.SampleTime
+import org.openjdk.jmh.annotations.Mode
 import org.openjdk.jmh.annotations._
 
 @State(Scope.Benchmark)
-@BenchmarkMode(Array(SampleTime))
+@BenchmarkMode(Array(org.openjdk.jmh.annotations.Mode.SampleTime))
 @OutputTimeUnit(TimeUnit.MILLISECONDS)
 @Warmup(iterations = 10, time = 10, timeUnit = TimeUnit.SECONDS)
 @Measurement(iterations = 10, time = 10, timeUnit = TimeUnit.SECONDS)
diff --git a/compilation/src/main/scala/scala/tools/nsc/ScalacBenchmark.scala b/compilation/src/main/scala/scala/tools/nsc/ScalacBenchmark.scala
index 3d1548f..d527f51 100644
--- a/compilation/src/main/scala/scala/tools/nsc/ScalacBenchmark.scala
+++ b/compilation/src/main/scala/scala/tools/nsc/ScalacBenchmark.scala
@@ -111,7 +111,7 @@ object ScalacBenchmarkStandalone {
 }
 
 @State(Scope.Benchmark)
-@BenchmarkMode(Array(SingleShotTime))
+@BenchmarkMode(Array(org.openjdk.jmh.annotations.Mode.SingleShotTime))
 @OutputTimeUnit(TimeUnit.MILLISECONDS)
 // TODO -Xbatch reduces fork-to-fork variance, but incurs 5s -> 30s slowdown
 @Fork(value = 16, jvmArgs = Array("-XX:CICompilerCount=2", "-Xms2G", "-Xmx2G"))
@@ -120,7 +120,7 @@ class ColdScalacBenchmark extends ScalacBenchmark {
   def compile(): Unit = compileImpl()
 }
 
-@BenchmarkMode(Array(SampleTime))
+@BenchmarkMode(Array(org.openjdk.jmh.annotations.Mode.SampleTime))
 @OutputTimeUnit(TimeUnit.MILLISECONDS)
 @Warmup(iterations = 0)
 @Measurement(iterations = 1, time = 30, timeUnit = TimeUnit.SECONDS)
@@ -130,7 +130,7 @@ class WarmScalacBenchmark extends ScalacBenchmark {
   def compile(): Unit = compileImpl()
 }
 
-@BenchmarkMode(Array(SampleTime))
+@BenchmarkMode(Array(org.openjdk.jmh.annotations.Mode.SampleTime))
 @OutputTimeUnit(TimeUnit.MILLISECONDS)
 @Warmup(iterations = 10, time = 10, timeUnit = TimeUnit.SECONDS)
 @Measurement(iterations = 10, time = 10, timeUnit = TimeUnit.SECONDS)

[Blaisorblade]

See #1686 for the underlying trap, and #3925 (comment) for the standard trick to fix it by using desugarIdent.