A brand new, fast classfile parser.

Try it: ./tools/dump-class ./build/quick/classes

The output is intended to be easy to filter on the command line.
This is a starting point for lots of interesting bytecode analysis
for which we have waited too long.

Example.  All generic signatures we produce.

  // almost 20K classfiles
  % find build/quick/classes -name '*.class' |wc -l
      18519

  // fully parsed in 6 seconds
  tools/dump-class build/quick/classes |grep "^  signature" | wc -l
      50802

  real	0m6.230s

It's designed to be easy to make faster if you don't care about
particular classfile bits; you can override those methods to jump
forward in the input stream rather than building a structure.
For just a little sampling, here are our most frequently
repeated name/signature combinations.

194   signature               <init>  ()V   // this one is weird, wonder why there's a generic signature
115   signature    $div$colon$bslash  <A1:Ljava/lang/Object;>(TA1;Lscala/Function2<TA1;TA1;TA1;>;)TA1;
105   signature          applyOrElse  <A1:Ljava/lang/Object;B1:Ljava/lang/Object;>(TA1;Lscala/Function1<TA1;TB1;>;)TB1;
103   signature                 view  ()Ljava/lang/Object;
101   signature                toSet  <B:Ljava/lang/Object;>()Lscala/collection/immutable/Set<TB;>;

And the top five name/descriptor combinations.

11170   descriptor           <clinit>  ()V
10155   descriptor   serialVersionUID  J
7130   descriptor              apply  (Ljava/lang/Object;)Ljava/lang/Object;
3028   descriptor              apply  ()Ljava/lang/Object;
2426   descriptor             <init>  ()V

3 files changed, 30 insertions, 0 deletions

diff --git a/test/files/run/inner-parse/J_1.java b/test/files/run/inner-parse/J_1.java
new file mode 100644
index 0000000000..920ab951ab
--- /dev/null
+++ b/test/files/run/inner-parse/J_1.java
@@ -0,0 +1,9 @@
+package j;
+
+public class J_1 implements java.util.RandomAccess {  // "random" marker interface
+  class B {
+    class C {
+      class D { }
+    }
+  }
+}
diff --git a/test/files/run/inner-parse/S_2.scala b/test/files/run/inner-parse/S_2.scala
new file mode 100644
index 0000000000..fd144a40b7
--- /dev/null
+++ b/test/files/run/inner-parse/S_2.scala
@@ -0,0 +1,9 @@
+package s;
+
+class J_1 extends java.util.RandomAccess {
+  class B {
+    class C {
+      class D { }
+    }
+  }
+}
diff --git a/test/files/run/inner-parse/S_3.scala b/test/files/run/inner-parse/S_3.scala
new file mode 100644
index 0000000000..296a651460
--- /dev/null
+++ b/test/files/run/inner-parse/S_3.scala
@@ -0,0 +1,12 @@
+import scala.reflect.internal.JvmClassInfo
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val cwd = sys.props("partest.output")
+    
+    for ((f, info) <- JvmClassInfo.classInfoList(cwd)) {
+      println("file " + f.stripPrefix(cwd + "/"))
+      println(info)
+    }
+  }
+}