[RFA/JVMTI] Breakpoint class

[Keith Seitz <keiths at redhat dot com>]

Hi,

This patch adds a gnu.gcj.jvmti.Breakpoint class which represents a 
breakpoint installed in the interpreter, holding information about the 
original instruction. Another manager class which keeps track of all 
these things is to follow after this one.

Keith

ChangeLog
2006-10-27  Keith Seitz  <keiths@redhat.com>

        * Makefile.am (nat_source_files): Add natBreakpoint.cc.
	* Makefile.in: Regenerate.
        * gnu/gcj/jvmti/Breakpoint.java: New file.
        * gnu/gcj/jvmti/natBreakpoint.java: New file.

Index: Makefile.am
===================================================================
--- Makefile.am	(revision 118009)
+++ Makefile.am	(working copy)
@@ -818,6 +818,7 @@
 gnu/gcj/convert/natOutput_SJIS.cc \
 gnu/gcj/io/natSimpleSHSStream.cc \
 gnu/gcj/io/shs.cc \
+gnu/gcj/jvmti/natBreakpoint.cc \
 gnu/gcj/runtime/natFinalizerThread.cc \
 gnu/gcj/runtime/natSharedLibLoader.cc \
 gnu/gcj/runtime/natSystemClassLoader.cc \
Index: gnu/gcj/jvmti/Breakpoint.java
===================================================================
--- gnu/gcj/jvmti/Breakpoint.java	(revision 0)
+++ gnu/gcj/jvmti/Breakpoint.java	(revision 0)
@@ -0,0 +1,57 @@
+// Breakpoint.java -  a breakpoint in the interpreter
+
+/* Copyright (C) 2006  Free Software Foundation
+
+   This file is part of libgcj.
+
+This software is copyrighted work licensed under the terms of the
+Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
+details.  */
+
+package gnu.gcj.jvmti;
+
+import gnu.gcj.RawDataManaged;
+
+/**
+ * Class representing a Breakpoint.
+ *
+ * @author Keith Seitz (keiths@redhat.com)
+ */
+public class Breakpoint
+{
+  // Location of this breakpoint
+  private long method;
+  private long location;
+
+  // The original instruction that this breakpoint replaced
+  private RawDataManaged data;
+
+  /**
+   * Constructs a new Breakpoint. SetBreakpoint will verify the
+   * validity of the arguments.
+   *
+   * @param method the method (a jmethodID)
+   * @param location the jlocation of the breakpoint (a jlocation)
+   */
+  public Breakpoint (long method, long location)
+  {
+    this.method = method;
+    this.location = location;
+    initialize_native ();
+  }
+
+  private native void initialize_native ();
+
+  public native void install ();
+
+  public native void remove ();
+
+  /**
+   * Returns the original instruction at the location where
+   * this breakpoint was set
+   */
+  public RawDataManaged getInsn ()
+  {
+    return data;
+  }
+}
Index: gnu/gcj/jvmti/natBreakpoint.cc
===================================================================
--- gnu/gcj/jvmti/natBreakpoint.cc	(revision 0)
+++ gnu/gcj/jvmti/natBreakpoint.cc	(revision 0)
@@ -0,0 +1,57 @@
+// natBreakpoint.cc - C++ side of Breakpoint
+
+/* Copyright (C) 2006  Free Software Foundation
+
+   This file is part of libgcj.
+
+This software is copyrighted work licensed under the terms of the
+Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
+details.  */
+
+#include <config.h>
+#include <gcj/cni.h>
+#include <gcj/method.h>
+#include <java-interp.h>
+#include <java-insns.h>
+#include <java-assert.h>
+#include <jvmti.h>
+
+#include <gnu/gcj/jvmti/Breakpoint.h>
+
+static _Jv_InterpMethod *
+get_interp_method (jlong method)
+{
+  jmethodID id = reinterpret_cast<jmethodID> (method);
+  jclass klass = _Jv_GetMethodDeclaringClass (id);
+  JvAssert (_Jv_IsInterpretedClass (klass));
+  _Jv_MethodBase *base
+    = _Jv_FindInterpreterMethod (klass, id);
+  JvAssert (base != NULL);
+  return reinterpret_cast<_Jv_InterpMethod *> (base);
+}
+
+void
+gnu::gcj::jvmti::Breakpoint::initialize_native ()
+{
+  _Jv_InterpMethod *imeth = get_interp_method (method);
+
+  // copy contents of insn at location into data
+  pc_t code = imeth->get_insn (location);
+  data = (RawDataManaged *) JvAllocBytes (sizeof (*code));
+  memcpy (data, code, sizeof (*code));
+  install ();
+}
+
+void
+gnu::gcj::jvmti::Breakpoint::install ()
+{
+  _Jv_InterpMethod *imeth = get_interp_method (method);
+  imeth->install_break (location);
+}
+
+void
+gnu::gcj::jvmti::Breakpoint::remove ()
+{
+  _Jv_InterpMethod *imeth = get_interp_method (method);
+  imeth->set_insn (location, reinterpret_cast<pc_t> (data));
+}