Read version 51 (JDK 7) class files.

This commit makes the ClassFileReader/ICodeReader parse class files
from JDK 7 (class file version 51). It does that by skipping over
the method handle related entries in the constant pool and by doing
some dummy processing on invoke dynamic instructions. The inliner
is updated to not try to inline a method with an invoke dynamic
instruction. A place holder INVOKE_DYNAMIC instruction is added to ICode
but it is designed to create an error if there's ever any attempt to
analyze it. Because the inliner is the only phase that ever tries
to analyze ICode instructions not generated from Scala source and
because Scala source will never emit an INVOKE_DYNAMIC, the place
holder INVOKE_DYNAMIC should never cause any errors.

A test is included that generates a class file with INVOKE_DYNAMIC
and then compiles Scala code that depends on it.

5 files changed, 34 insertions, 2 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/icode/Members.scala b/src/compiler/scala/tools/nsc/backend/icode/Members.scala
index 7ba212f42e..b74770f051 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/Members.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/Members.scala
@@ -171,6 +171,7 @@ trait Members {
     var returnType: TypeKind = _
     var recursive: Boolean = false
     var bytecodeHasEHs = false // set by ICodeReader only, used by Inliner to prevent inlining (SI-6188)
+    var bytecodeHasInvokeDynamic = false // set by ICodeReader only, used by Inliner to prevent inlining until we have proper invoke dynamic support
 
     /** local variables and method parameters */
     var locals: List[Local] = Nil
diff --git a/src/compiler/scala/tools/nsc/backend/icode/Opcodes.scala b/src/compiler/scala/tools/nsc/backend/icode/Opcodes.scala
index 8c9a72638d..a3a0edb35d 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/Opcodes.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/Opcodes.scala
@@ -409,6 +409,25 @@ trait Opcodes { self: ICodes =>
 
       override def category = mthdsCat
     }
+    
+    /**
+     * A place holder entry that allows us to parse class files with invoke dynamic
+     * instructions. Because the compiler doesn't yet really understand the
+     * behavior of invokeDynamic, this op acts as a poison pill. Any attempt to analyze
+     * this instruction will cause a failure. The only optimization that
+     * should ever look at non-Scala generated icode is the inliner, and it
+     * has been modified to not examine any method with invokeDynamic 
+     * instructions. So if this poison pill ever causes problems then
+     * there's been a serious misunderstanding
+     */
+    // TODO do the real thing
+    case class INVOKE_DYNAMIC(poolEntry: Char) extends Instruction {
+      private def error = sys.error("INVOKE_DYNAMIC is not fully implemented and should not be analyzed")
+      override def consumed = error
+      override def produced = error
+      override def producedTypes = error
+      override def category = error
+    }
 
     case class BOX(boxType: TypeKind) extends Instruction {
       assert(boxType.isValueType && (boxType ne UNIT)) // documentation
diff --git a/src/compiler/scala/tools/nsc/backend/opt/Inliners.scala b/src/compiler/scala/tools/nsc/backend/opt/Inliners.scala
index 521b6cc132..498db78636 100644
--- a/src/compiler/scala/tools/nsc/backend/opt/Inliners.scala
+++ b/src/compiler/scala/tools/nsc/backend/opt/Inliners.scala
@@ -961,6 +961,7 @@ abstract class Inliners extends SubComponent {
             if(isInlineForbidden)  { rs ::= "is annotated @noinline" }
             if(inc.isSynchronized) { rs ::= "is synchronized method" }
             if(inc.m.bytecodeHasEHs) { rs ::= "bytecode contains exception handlers / finally clause" } // SI-6188
+            if(inc.m.bytecodeHasInvokeDynamic) { rs ::= "bytecode contains invoke dynamic" }
             if(rs.isEmpty) null else rs.mkString("", ", and ", "")
           }
 
diff --git a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
index 1f42fa8aab..29cac86c16 100644
--- a/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
+++ b/src/compiler/scala/tools/nsc/symtab/classfile/ClassfileParser.scala
@@ -137,10 +137,13 @@ abstract class ClassfileParser {
         (in.nextByte.toInt: @switch) match {
           case CONSTANT_UTF8 | CONSTANT_UNICODE =>
             in.skip(in.nextChar)
-          case CONSTANT_CLASS | CONSTANT_STRING =>
+          case CONSTANT_CLASS | CONSTANT_STRING | CONSTANT_METHODTYPE=>
             in.skip(2)
+          case CONSTANT_METHODHANDLE =>
+            in.skip(3)
           case CONSTANT_FIELDREF | CONSTANT_METHODREF | CONSTANT_INTFMETHODREF
-             | CONSTANT_NAMEANDTYPE | CONSTANT_INTEGER | CONSTANT_FLOAT =>
+             | CONSTANT_NAMEANDTYPE | CONSTANT_INTEGER | CONSTANT_FLOAT
+             | CONSTANT_INVOKEDYNAMIC =>
             in.skip(4)
           case CONSTANT_LONG | CONSTANT_DOUBLE =>
             in.skip(8)
diff --git a/src/compiler/scala/tools/nsc/symtab/classfile/ICodeReader.scala b/src/compiler/scala/tools/nsc/symtab/classfile/ICodeReader.scala
index 13c0d8993a..d38907d182 100644
--- a/src/compiler/scala/tools/nsc/symtab/classfile/ICodeReader.scala
+++ b/src/compiler/scala/tools/nsc/symtab/classfile/ICodeReader.scala
@@ -506,6 +506,12 @@ abstract class ICodeReader extends ClassfileParser {
             code.emit(UNBOX(toTypeKind(m.info.resultType)))
           else
             code.emit(CALL_METHOD(m, Static(false)))
+        case JVM.invokedynamic  =>
+          // TODO, this is just a place holder. A real implementation must parse the class constant entry
+          containsInvokeDynamic = true
+          val poolEntry = in.nextChar
+          in.skip(2)
+          code.emit(INVOKE_DYNAMIC(poolEntry))
 
         case JVM.new_          =>
           code.emit(NEW(REFERENCE(pool.getClassSymbol(in.nextChar))))
@@ -644,6 +650,7 @@ abstract class ICodeReader extends ClassfileParser {
     var containsDUPX = false
     var containsNEW  = false
     var containsEHs  = false
+    var containsInvokeDynamic = false
 
     def emit(i: Instruction) {
       instrs += ((pc, i))
@@ -662,6 +669,7 @@ abstract class ICodeReader extends ClassfileParser {
       val code = new Code(method)
       method.setCode(code)
       method.bytecodeHasEHs = containsEHs
+      method.bytecodeHasInvokeDynamic = containsInvokeDynamic
       var bb = code.startBlock
 
       def makeBasicBlocks: mutable.Map[Int, BasicBlock] =