Allow considering all SCCs bad

Author: ysthakur

bench.nu

@@ -1,14 +1,14 @@
 const jar = "fred.jar"
 const outExe = "bench.bin"
 
-export def run [ file: string, lazyMarkScanOnly: bool ] {
+export def run [ file: string, lazyMarkScanOnly: bool, allSccsBad: bool ] {
   let benchName = $file | path basename
-  if $lazyMarkScanOnly {
-    java -jar $jar $file -o $outExe --lazy-mark-scan-only
-  } else {
-    java -jar $jar $file -o $outExe
-  }
-  print $"Compiled ($file) \(lazy-mark-scan-only: ($lazyMarkScanOnly))"
+  let opts = [
+    ...(if $lazyMarkScanOnly { [--lazy-mark-scan-only] } else { [] }),
+    ...(if $allSccsBad { [--all-sccs-bad] } else { [] })
+  ]
+  java -jar $jar $file -o $outExe ...$opts
+  print $"Compiled ($file) \(lazy-mark-scan-only: ($lazyMarkScanOnly), all-sccs-bad: ($allSccsBad))"
   let out = ^$"./($outExe)"
   print $out
   let res = (
@@ -20,12 +20,19 @@ export def run [ file: string, lazyMarkScanOnly: bool ] {
     Name: $benchName,
     "Timestamp counter": $res.tsc,
     Clock: $res.clock,
-    "Lazy mark scan only": $lazyMarkScanOnly
+    "Lazy mark scan only": $lazyMarkScanOnly,
+    "All SCCs bad": $allSccsBad,
   }
 }
 
-export def run-all [ ] {
-  let files = (ls benchmarks/*.fred).name
-  let results = $files | each { |file| [(run $file false), (run $file true)] }
+export def run-all [ files: glob = benchmarks/*.fred ] {
+  let results = glob $files | each { |file|
+      [
+        (run $file false false),
+        (run $file false true),
+        (run $file true false),
+        (run $file true true)
+      ]
+    }
   $results | flatten
 }

benchmarks/game.fred

@@ -2,7 +2,8 @@ data Player
   = Player { store: Store }
   // This exists only to make the compiler think that Player can be involved in cycles
   | PlayerCyclic {
-    mut player: Player
+    // With the --all-sccs-bad flag enabled, this would make the compiler think there could be a cycle
+    player: Player
   }
 
 // Represents some shared data that all Player objects have a reference to
@@ -11,8 +12,8 @@ data Store = Store { datums: Data }
 data Data
   = DataCons {
     value: int,
-    // This is mut only so the compiler thinks there can be a cycle at runtime
-    mut next: Data
+    // This would need to be mut for the compiler to think there could be a cycle at runtime
+    next: Data
   }
   | DataNil {}
 

src/main/scala/fred/Compiler.scala

@@ -2,16 +2,17 @@ package fred
 
 import scala.sys.process.*
 import java.io.File
-
-import scopt.OParser
 import java.nio.file.Files
 import java.nio.file.Path
 
+import scopt.OParser
+
 object Compiler {
   private val RuntimeHeader = "runtime/runtime.h"
 
   case class Settings(
       rcAlgo: RcAlgo = RcAlgo.Mine,
+      allSccsBad: Boolean = false,
       includeMemcheck: Boolean = false
   )
 
@@ -37,7 +38,12 @@ object Compiler {
           .text("Output executable (default: a.out)"),
         opt[Unit]("lazy-mark-scan-only").action((_, opts) =>
           opts.copy(settings = opts.settings.copy(rcAlgo = RcAlgo.LazyMarkScan))
-        ).text("Use base lazy mark scan algorithm instead of my cool one :(")
+        ).text("Use base lazy mark scan algorithm instead of my cool one :("),
+        opt[Unit]("all-sccs-bad").action((_, opts) =>
+          opts.copy(settings = opts.settings.copy(allSccsBad = true))
+        ).text(
+          "Consider all SCCs to be bad, i.e., act like all fields are mutable and that any type SCC can have cycles at runtime"
+        )
       )
     }
     OParser.parse(parser, args, Options()) match {

src/main/scala/fred/Translator.scala

@@ -29,7 +29,12 @@ object Translator {
           // whole program, make this an empty set in that case
           Set(0)
         )
-      case RcAlgo.Mine => Cycles.fromFile(file)
+      case RcAlgo.Mine => {
+        val cycles = Cycles.fromFile(file)
+        if (settings.allSccsBad) cycles
+          .copy(badSCCs = cycles.sccs.indices.toSet)
+        else cycles
+      }
     }
     val helper = Helper(typer, cycles)
     val (genDecls, genImpls) =