Build a call graph for inlining decisions

Inlining decisions will be taken by analyzing the ASM bytecode. This
commit adds tools to build a call graph representation that can be
used for these decisions.

The call graph is currently built by considering method descriptors of
callsite instructions. It will become more precise by using data flow
analyses.

1 files changed, 8 insertions, 2 deletions

diff --git a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
index d7f4cca615..9674b4cfae 100644
--- a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
+++ b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala
@@ -222,6 +222,8 @@ trait ScalaSettings extends AbsScalaSettings
     val emptyLineNumbers        = Choice("empty-line-numbers",        "Eliminate unnecessary line number information.")
     val emptyLabels             = Choice("empty-labels",              "Eliminate and collapse redundant labels in the bytecode.")
     val compactLocals           = Choice("compact-locals",            "Eliminate empty slots in the sequence of local variables.")
+    val inlineProject           = Choice("inline-project",            "Inline only methods defined in the files being compiled")
+    val inlineGlobal            = Choice("inline-global",             "Inline methods from any source, including classfiles on the compile classpath")
 
     val lNone           = Choice("l:none",      "Don't enable any optimizations.")
 
@@ -231,10 +233,10 @@ trait ScalaSettings extends AbsScalaSettings
     private val methodChoices = List(unreachableCode, simplifyJumps, recurseUnreachableJumps, emptyLineNumbers, emptyLabels, compactLocals)
     val lMethod         = Choice("l:method",    "Enable intra-method optimizations: "+ methodChoices.mkString(","),                                expandsTo = methodChoices)
 
-    private val projectChoices = List(lMethod)
+    private val projectChoices = List(lMethod, inlineProject)
     val lProject        = Choice("l:project",   "Enable cross-method optimizations within the current project: "+ projectChoices.mkString(","),    expandsTo = projectChoices)
 
-    private val classpathChoices = List(lProject)
+    private val classpathChoices = List(lProject, inlineGlobal)
     val lClasspath      = Choice("l:classpath", "Enable cross-method optimizations across the entire classpath: "+ classpathChoices.mkString(","), expandsTo = classpathChoices)
   }
 
@@ -252,6 +254,10 @@ trait ScalaSettings extends AbsScalaSettings
   def YoptEmptyLabels             = Yopt.contains(YoptChoices.emptyLabels)
   def YoptCompactLocals           = Yopt.contains(YoptChoices.compactLocals)
 
+  def YoptInlineProject           = Yopt.contains(YoptChoices.inlineProject)
+  def YoptInlineGlobal            = Yopt.contains(YoptChoices.inlineGlobal)
+  def YoptInlinerEnabled          = YoptInlineProject || YoptInlineGlobal
+
   private def removalIn212 = "This flag is scheduled for removal in 2.12. If you have a case where you need this flag then please report a bug."
 
   object YstatisticsPhases extends MultiChoiceEnumeration { val parser, typer, patmat, erasure, cleanup, jvm = Value }