Generate SYNTHETIC flags.

Dont emit debugging info for synthetic variables.
Added the SYNTHETIC flag to some local vars created by the compiler.

3 files changed, 34 insertions, 18 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala b/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
index 931a041d3f..9885f06034 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
@@ -463,6 +463,7 @@ abstract class GenICode extends SubComponent  {
             handlers = Pair(NoSymbol, {
                             ctx: Context =>
                               val exception = new Local(ctx.method.symbol.newVariable(finalizer.pos, unit.fresh.newName("exc"))
+                                    .setFlag(Flags.SYNTHETIC)
                                     .setInfo(definitions.ThrowableClass.tpe),
                                   REFERENCE(definitions.ThrowableClass), false);
                               ctx.method.addLocal(exception);
@@ -479,7 +480,7 @@ abstract class GenICode extends SubComponent  {
               generatedType = kind; //toTypeKind(block.tpe);
               val ctx1 = genLoad(block, bodyCtx, generatedType);
               if (kind != UNIT && mayCleanStack(finalizer)) {
-                val tmp = new Local(ctx.method.symbol.newVariable(tree.pos, unit.fresh.newName("tmp")).setInfo(tree.tpe),
+                val tmp = new Local(ctx.method.symbol.newVariable(tree.pos, unit.fresh.newName("tmp")).setInfo(tree.tpe).setFlag(Flags.SYNTHETIC),
                     kind, false);
                 ctx1.method.addLocal(tmp);
                 ctx1.bb.emit(STORE_LOCAL(tmp));
@@ -651,7 +652,8 @@ abstract class GenICode extends SubComponent  {
               generatedType = BOOL;
               ctx1 = afterCtx;
             } else if (code == scalaPrimitives.SYNCHRONIZED) {
-              val monitor = new Local(ctx.method.symbol.newVariable(tree.pos, unit.fresh.newName("monitor")).setInfo(definitions.ObjectClass.tpe),
+              val monitor = new Local(ctx.method.symbol.newVariable(tree.pos, unit.fresh.newName("monitor"))
+                                      .setInfo(definitions.ObjectClass.tpe).setFlag(Flags.SYNTHETIC),
                                       ANY_REF_CLASS, false);
               ctx.method.addLocal(monitor);
 
@@ -1246,7 +1248,7 @@ abstract class GenICode extends SubComponent  {
       ctx.method.lookupLocal(eqEqTemp) match {
         case Some(local) => eqEqTempVar = local.sym; eqEqTempLocal = local;
         case None =>
-          eqEqTempVar = ctx.method.symbol.newVariable(l.pos, eqEqTemp);
+          eqEqTempVar = ctx.method.symbol.newVariable(l.pos, eqEqTemp).setFlag(Flags.SYNTHETIC);
           eqEqTempVar.setInfo(definitions.AnyRefClass.typeConstructor);
           eqEqTempLocal = new Local(eqEqTempVar, REFERENCE(definitions.AnyRefClass), false);
           ctx.method.addLocal(eqEqTempLocal);
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/GenJVM.scala b/src/compiler/scala/tools/nsc/backend/jvm/GenJVM.scala
index eedf108b36..8f45d4f777 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/GenJVM.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/GenJVM.scala
@@ -391,7 +391,7 @@ abstract class GenJVM extends SubComponent {
         jcode = jmethod.getCode().asInstanceOf[JExtendedCode];
         genCode(m);
         if (emitVars)
-          genLocalVariableTable;
+          genLocalVariableTable(m);
       }
 
       addExceptionsAttribute(m.symbol)
@@ -1178,6 +1178,7 @@ abstract class GenJVM extends SubComponent {
 
       var jf: Int = 0;
       val f = sym.flags;
+      jf = jf | (if (sym hasFlag Flags.SYNTHETIC) ACC_SYNTHETIC else 0);
       jf = jf | (if (sym hasFlag Flags.PRIVATE) ACC_PRIVATE else ACC_PUBLIC);
       jf = jf | (if ((sym hasFlag Flags.ABSTRACT) ||
                      (sym hasFlag Flags.DEFERRED)) ACC_ABSTRACT else 0);
@@ -1226,29 +1227,41 @@ abstract class GenJVM extends SubComponent {
       settings.outdir.value + File.separatorChar + path + suffix
     }
 
-    private def genLocalVariableTable: Unit = {
-        val vars: Array[JLocalVariable] = jmethod.getLocalVariables();
+    /** Emit a Local variable table for debugging purposes.
+     *  Synthetic locals are skipped. All variables are method-scoped.
+     */
+    private def genLocalVariableTable(m: IMethod): Unit = {
+        var vars = m.locals.filter(l => !l.sym.hasFlag(Flags.SYNTHETIC));
 
-        if (vars.length == 0)
-            return;
+        if (vars.length == 0) return;
 
         val pool = jclass.getConstantPool();
         val pc = jcode.getPC();
         var anonCounter = 0;
+        val locals = if (jmethod.isStatic()) vars.length else 1 + vars.length;
+
+        val lvTab = ByteBuffer.allocate(2 + 10 * locals);
+        def emitEntry(name: String, signature: String, idx: Short): Unit = {
+          lvTab.putShort(0.asInstanceOf[Short]);
+          lvTab.putShort(pc.asInstanceOf[Short]);
+          lvTab.putShort(pool.addUtf8(name).asInstanceOf[Short]);
+          lvTab.putShort(pool.addUtf8(signature).asInstanceOf[Short]);
+          lvTab.putShort(idx);
+        }
+
+        lvTab.putShort(locals.asInstanceOf[Short]);
+
+        if (!jmethod.isStatic()) {
+          emitEntry("this", jclass.getType().getSignature(), 0);
+        }
 
-        val lvTab = ByteBuffer.allocate(2 + 10 * vars.length);
-        lvTab.putShort(vars.length.asInstanceOf[Short]);
         for (val lv <- vars) {
-            val name = if (lv.getName() == null) {
+            val name = if (javaName(lv.sym) eq null) {
               anonCounter = anonCounter + 1;
               "<anon" + anonCounter + ">"
-            } else lv.getName();
+            } else javaName(lv.sym)
 
-            lvTab.putShort(0.asInstanceOf[Short]);
-            lvTab.putShort(pc.asInstanceOf[Short]);
-            lvTab.putShort(pool.addUtf8(name).asInstanceOf[Short]);
-            lvTab.putShort(pool.addUtf8(lv.getType().getSignature()).asInstanceOf[Short]);
-            lvTab.putShort(lv.getIndex().asInstanceOf[Short]);
+            emitEntry(name, javaType(lv.kind).getSignature(), indexOf(lv).asInstanceOf[Short]);
         }
         val attr =
             fjbgContext.JOtherAttribute(jclass,
diff --git a/src/compiler/scala/tools/nsc/matching/PatternNodeCreator.scala b/src/compiler/scala/tools/nsc/matching/PatternNodeCreator.scala
index 23f1f7fa45..092be313c6 100644
--- a/src/compiler/scala/tools/nsc/matching/PatternNodeCreator.scala
+++ b/src/compiler/scala/tools/nsc/matching/PatternNodeCreator.scala
@@ -1,6 +1,7 @@
 package scala.tools.nsc.matching;
 
 import scala.tools.nsc.util.Position;
+import scala.tools.nsc.symtab.Flags;
 
 /** PatternNode factory.
  *  we inherit the globals from PatternTool.
@@ -112,7 +113,7 @@ trait PatternNodeCreator requires (TransMatcher with PatternNodes) {
   }
 
   def newVar(pos: int, tpe: Type): Symbol = {
-    newVar(pos, cunit.fresh.newName("temp"), tpe);
+    newVar(pos, cunit.fresh.newName("temp"), tpe).setFlag(Flags.SYNTHETIC);
   }
 }