INTRO-581 move mdb_v8 into illumos-joyent

6 files changed, 2780 insertions, 1 deletions

diff --git a/manifest b/manifest
index 672c463ec5..b03f1b678d 100644
--- a/manifest
+++ b/manifest
@@ -9500,6 +9500,7 @@ f usr/lib/mdb/proc/mdb_ds.so 0555 root sys
 f usr/lib/mdb/proc/mdb_test.so 0555 root sys
 f usr/lib/mdb/proc/svc.configd.so 0555 root sys
 f usr/lib/mdb/proc/svc.startd.so 0555 root sys
+f usr/lib/mdb/proc/v8.so 0555 root sys
 d usr/lib/mdb/raw 0755 root sys
 d usr/lib/mdb/raw/amd64 0755 root sys
 f usr/lib/mdb/raw/amd64/dof.so 0555 root sys
diff --git a/usr/src/cmd/mdb/Makefile.common b/usr/src/cmd/mdb/Makefile.common
index 4e282bf001..3bbca8d4e0 100644
--- a/usr/src/cmd/mdb/Makefile.common
+++ b/usr/src/cmd/mdb/Makefile.common
@@ -45,7 +45,8 @@ COMMON_MODULES_PROC = \
 #
 COMMON_MODULES_PROC_32BIT = \
 	svc.configd \
-	svc.startd
+	svc.startd  \
+	v8
 
 #
 # MDB modules used for debugging kernels.
diff --git a/usr/src/cmd/mdb/common/modules/v8/mdb_v8.c b/usr/src/cmd/mdb/common/modules/v8/mdb_v8.c
new file mode 100644
index 0000000000..7f4d2e7110
--- /dev/null
+++ b/usr/src/cmd/mdb/common/modules/v8/mdb_v8.c
@@ -0,0 +1,1939 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2011, Joyent, Inc. All rights reserved.
+ */
+
+/*
+ * mdb(1M) module for debugging the V8 JavaScript engine.  This implementation
+ * makes heavy use of metadata defined in the V8 binary for inspecting in-memory
+ * structures.  Canned configurations can be manually loaded for V8 binaries
+ * that predate this metadata.  See mdb_v8_cfg.c for details.
+ */
+
+#include <assert.h>
+#include <ctype.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <sys/mdb_modapi.h>
+
+#include "v8dbg.h"
+#include "v8cfg.h"
+
+/*
+ * The "v8_class" and "v8_field" structures describe the C++ classes used to
+ * represent V8 heap objects.
+ */
+typedef struct v8_class {
+	struct v8_class *v8c_next;	/* list linkage */
+	struct v8_class *v8c_parent;	/* parent class (inheritance) */
+	struct v8_field *v8c_fields;	/* array of class fields */
+	size_t		v8c_start;	/* offset of first class field */
+	size_t		v8c_end;	/* offset of first subclass field */
+	char		v8c_name[64];	/* heap object class name */
+} v8_class_t;
+
+typedef struct v8_field {
+	struct v8_field	*v8f_next;	/* list linkage */
+	ssize_t		v8f_offset;	/* field offset */
+	char 		v8f_name[64];	/* field name */
+	boolean_t	v8f_isbyte;	/* 1-byte int field */
+} v8_field_t;
+
+/*
+ * Similarly, the "v8_enum" structure describes an enum from V8.
+ */
+typedef struct {
+	char 	v8e_name[64];
+	uint_t	v8e_value;
+} v8_enum_t;
+
+/*
+ * During configuration, the dmod updates these globals with the actual set of
+ * classes, types, and frame types based on the debug metadata.
+ */
+static v8_class_t	*v8_classes;
+
+static v8_enum_t	v8_types[128];
+static int 		v8_next_type;
+
+static v8_enum_t 	v8_frametypes[16];
+static int 		v8_next_frametype;
+
+/*
+ * The following constants describe offsets from the frame pointer that are used
+ * to inspect each stack frame.  They're initialized from the debug metadata.
+ */
+static ssize_t	V8_OFF_FP_CONTEXT;
+static ssize_t	V8_OFF_FP_MARKER;
+static ssize_t	V8_OFF_FP_FUNCTION;
+static ssize_t	V8_OFF_FP_ARGS;
+
+/*
+ * The following constants are used by macros defined in heap-dbg-common.h to
+ * examine the types of various V8 heap objects.  In general, the macros should
+ * be preferred to using the constants directly.  The values of these constants
+ * are initialized from the debug metadata.
+ */
+static intptr_t	V8_FirstNonstringType;
+static intptr_t	V8_IsNotStringMask;
+static intptr_t	V8_StringTag;
+static intptr_t	V8_NotStringTag;
+static intptr_t	V8_StringEncodingMask;
+static intptr_t	V8_TwoByteStringTag;
+static intptr_t	V8_AsciiStringTag;
+static intptr_t	V8_StringRepresentationMask;
+static intptr_t	V8_SeqStringTag;
+static intptr_t	V8_ConsStringTag;
+static intptr_t	V8_ExternalStringTag;
+static intptr_t	V8_FailureTag;
+static intptr_t	V8_FailureTagMask;
+static intptr_t	V8_HeapObjectTag;
+static intptr_t	V8_HeapObjectTagMask;
+static intptr_t	V8_SmiTag;
+static intptr_t	V8_SmiTagMask;
+static intptr_t	V8_SmiValueShift;
+static intptr_t	V8_PointerSizeLog2;
+
+static intptr_t	V8_PROP_IDX_CONTENT;
+static intptr_t	V8_PROP_IDX_FIRST;
+static intptr_t	V8_PROP_TYPE_FIELD;
+static intptr_t	V8_PROP_FIRST_PHANTOM;
+static intptr_t	V8_PROP_TYPE_MASK;
+
+/*
+ * Although we have this information in v8_classes, the following offsets are
+ * defined explicitly because they're used directly in code below.
+ */
+static ssize_t	V8_OFF_FIXEDARRAY_DATA;
+static ssize_t	V8_OFF_SEQASCIISTR_CHARS;
+
+static const char *V8_FIXEDARRAY_BASE;
+
+#define	NODE_OFF_EXTSTR_DATA		0x4	/* see node_string.h */
+
+/*
+ * Table of constants used directly by this file.
+ */
+typedef struct v8_constant {
+	intptr_t	*v8c_valp;
+	const char	*v8c_symbol;
+} v8_constant_t;
+
+static v8_constant_t v8_constants[] = {
+	{ &V8_OFF_FP_CONTEXT,		"v8dbg_off_fp_context"		},
+	{ &V8_OFF_FP_FUNCTION,		"v8dbg_off_fp_function"		},
+	{ &V8_OFF_FP_MARKER,		"v8dbg_off_fp_marker"		},
+	{ &V8_OFF_FP_ARGS,		"v8dbg_off_fp_args"		},
+
+	{ &V8_FirstNonstringType,	"v8dbg_FirstNonstringType"	},
+	{ &V8_IsNotStringMask,		"v8dbg_IsNotStringMask"		},
+	{ &V8_StringTag,		"v8dbg_StringTag"		},
+	{ &V8_NotStringTag,		"v8dbg_NotStringTag"		},
+	{ &V8_StringEncodingMask,	"v8dbg_StringEncodingMask"	},
+	{ &V8_TwoByteStringTag,		"v8dbg_TwoByteStringTag"	},
+	{ &V8_AsciiStringTag,		"v8dbg_AsciiStringTag"		},
+	{ &V8_StringRepresentationMask,	"v8dbg_StringRepresentationMask" },
+	{ &V8_SeqStringTag,		"v8dbg_SeqStringTag"		},
+	{ &V8_ConsStringTag,		"v8dbg_ConsStringTag"		},
+	{ &V8_ExternalStringTag,	"v8dbg_ExternalStringTag"	},
+	{ &V8_FailureTag,		"v8dbg_FailureTag"		},
+	{ &V8_FailureTagMask,		"v8dbg_FailureTagMask"		},
+	{ &V8_HeapObjectTag,		"v8dbg_HeapObjectTag"		},
+	{ &V8_HeapObjectTagMask,	"v8dbg_HeapObjectTagMask"	},
+	{ &V8_SmiTag,			"v8dbg_SmiTag"			},
+	{ &V8_SmiTagMask,		"v8dbg_SmiTagMask"		},
+	{ &V8_SmiValueShift,		"v8dbg_SmiValueShift"		},
+	{ &V8_PointerSizeLog2,		"v8dbg_PointerSizeLog2"		},
+
+	{ &V8_PROP_IDX_CONTENT,		"v8dbg_prop_idx_content"	},
+	{ &V8_PROP_IDX_FIRST,		"v8dbg_prop_idx_first"		},
+	{ &V8_PROP_TYPE_FIELD,		"v8dbg_prop_type_field"		},
+	{ &V8_PROP_FIRST_PHANTOM,	"v8dbg_prop_type_first_phantom"	},
+	{ &V8_PROP_TYPE_MASK,		"v8dbg_prop_type_mask"		},
+};
+
+static int v8_nconstants = sizeof (v8_constants) / sizeof (v8_constants[0]);
+
+static int autoconf_iter_symbol(mdb_symbol_t *, void *);
+static v8_class_t *conf_class_findcreate(const char *);
+static v8_field_t *conf_field_create(v8_class_t *, const char *, size_t);
+static char *conf_next_part(char *, char *);
+static int conf_update_parent(const char *);
+static int conf_update_field(v8_cfg_t *, const char *);
+static int conf_update_enum(v8_cfg_t *, const char *, const char *,
+    v8_enum_t *);
+static int conf_update_type(v8_cfg_t *, const char *);
+static int conf_update_frametype(v8_cfg_t *, const char *);
+static void conf_class_compute_offsets(v8_class_t *);
+
+static int heap_offset(const char *, const char *, ssize_t *, boolean_t);
+
+/*
+ * Invoked when this dmod is initially loaded to load the set of classes, enums,
+ * and other constants from the metadata in the target binary.
+ */
+static int
+autoconfigure(v8_cfg_t *cfgp)
+{
+	v8_class_t *clp;
+	struct v8_constant *cnp;
+	ssize_t unused;
+	int ii;
+
+	assert(v8_classes == NULL);
+
+	/*
+	 * Iterate all global symbols looking for metadata.
+	 */
+	if (cfgp->v8cfg_iter(cfgp, autoconf_iter_symbol, cfgp) != 0) {
+		mdb_warn("failed to autoconfigure V8 support\n");
+		return (-1);
+	}
+
+	/*
+	 * By now we've configured all of the classes so we can update the
+	 * "start" and "end" fields in each class with information from its
+	 * parent class.
+	 */
+	for (clp = v8_classes; clp != NULL; clp = clp->v8c_next) {
+		if (clp->v8c_end != (size_t)-1)
+			continue;
+
+		conf_class_compute_offsets(clp);
+	};
+
+	/*
+	 * Finally, load various constants used directly in the module.
+	 */
+	for (ii = 0; ii < v8_nconstants; ii++) {
+		cnp = &v8_constants[ii];
+
+		if (cfgp->v8cfg_readsym(cfgp, cnp->v8c_symbol,
+		    cnp->v8c_valp) == -1) {
+			mdb_warn("failed to read \"%s\"", cnp->v8c_symbol);
+			return (-1);
+		}
+	}
+
+	if (heap_offset("SeqAsciiString", "chars", &V8_OFF_SEQASCIISTR_CHARS,
+	    B_FALSE) != 0 || heap_offset("FixedArray", "data",
+	    &V8_OFF_FIXEDARRAY_DATA, B_FALSE) != 0)
+		return (-1);
+
+	/*
+	 * The V8 included in node v0.6 uses a FixedArrayBase class to contain
+	 * the "length" field, while the one in v0.4 has no such base class and
+	 * stores the field directly in FixedArray.  We handle both cases here.
+	 */
+	V8_FIXEDARRAY_BASE = heap_offset("FixedArray", "length", &unused,
+	    B_TRUE) == 0 ?  "FixedArray" : "FixedArrayBase";
+
+	return (0);
+}
+
+/* ARGSUSED */
+static int
+autoconf_iter_symbol(mdb_symbol_t *symp, void *arg)
+{
+	v8_cfg_t *cfgp = arg;
+
+	if (strncmp(symp->sym_name, "v8dbg_parent_",
+	    sizeof ("v8dbg_parent_") - 1) == 0)
+		return (conf_update_parent(symp->sym_name));
+
+	if (strncmp(symp->sym_name, "v8dbg_class_",
+	    sizeof ("v8dbg_class_") - 1) == 0)
+		return (conf_update_field(cfgp, symp->sym_name));
+
+	if (strncmp(symp->sym_name, "v8dbg_type_",
+	    sizeof ("v8dbg_type_") - 1) == 0)
+		return (conf_update_type(cfgp, symp->sym_name));
+
+	if (strncmp(symp->sym_name, "v8dbg_frametype_",
+	    sizeof ("v8dbg_frametype_") - 1) == 0)
+		return (conf_update_frametype(cfgp, symp->sym_name));
+
+	return (0);
+}
+
+/*
+ * Extracts the next field of a string whose fields are separated by "__" (as
+ * the V8 metadata symbols are).
+ */
+static char *
+conf_next_part(char *buf, char *start)
+{
+	char *pp;
+
+	if ((pp = strstr(start, "__")) == NULL) {
+		mdb_warn("malformed symbol name: %s\n", buf);
+		return (NULL);
+	}
+
+	*pp = '\0';
+	return (pp + sizeof ("__") - 1);
+}
+
+static v8_class_t *
+conf_class_findcreate(const char *name)
+{
+	v8_class_t *clp, *iclp, **ptr;
+	int cmp;
+
+	if (v8_classes == NULL || strcmp(v8_classes->v8c_name, name) > 0) {
+		ptr = &v8_classes;
+	} else {
+		for (iclp = v8_classes; iclp->v8c_next != NULL;
+		    iclp = iclp->v8c_next) {
+			cmp = strcmp(iclp->v8c_next->v8c_name, name);
+
+			if (cmp == 0)
+				return (iclp->v8c_next);
+
+			if (cmp > 0)
+				break;
+		}
+
+		ptr = &iclp->v8c_next;
+	}
+
+	if ((clp = mdb_zalloc(sizeof (*clp), UM_NOSLEEP)) == NULL)
+		return (NULL);
+
+	(void) strlcpy(clp->v8c_name, name, sizeof (clp->v8c_name));
+	clp->v8c_end = (size_t)-1;
+
+	clp->v8c_next = *ptr;
+	*ptr = clp;
+	return (clp);
+}
+
+static v8_field_t *
+conf_field_create(v8_class_t *clp, const char *name, size_t offset)
+{
+	v8_field_t *flp, *iflp;
+
+	if ((flp = mdb_zalloc(sizeof (*flp), UM_NOSLEEP)) == NULL)
+		return (NULL);
+
+	(void) strlcpy(flp->v8f_name, name, sizeof (flp->v8f_name));
+	flp->v8f_offset = offset;
+
+	if (clp->v8c_fields == NULL || clp->v8c_fields->v8f_offset > offset) {
+		flp->v8f_next = clp->v8c_fields;
+		clp->v8c_fields = flp;
+		return (flp);
+	}
+
+	for (iflp = clp->v8c_fields; iflp->v8f_next != NULL;
+	    iflp = iflp->v8f_next) {
+		if (iflp->v8f_next->v8f_offset > offset)
+			break;
+	}
+
+	flp->v8f_next = iflp->v8f_next;
+	iflp->v8f_next = flp;
+	return (flp);
+}
+
+/*
+ * Given a "v8dbg_parent_X__Y", symbol, update the parent of class X to class Y.
+ * Note that neither class necessarily exists already.
+ */
+static int
+conf_update_parent(const char *symbol)
+{
+	char *pp, *qq;
+	char buf[128];
+	v8_class_t *clp, *pclp;
+
+	(void) strlcpy(buf, symbol, sizeof (buf));
+	pp = buf + sizeof ("v8dbg_parent_") - 1;
+	qq = conf_next_part(buf, pp);
+
+	if (qq == NULL)
+		return (-1);
+
+	clp = conf_class_findcreate(pp);
+	pclp = conf_class_findcreate(qq);
+
+	if (clp == NULL || pclp == NULL) {
+		mdb_warn("mdb_v8: out of memory\n");
+		return (-1);
+	}
+
+	clp->v8c_parent = pclp;
+	return (0);
+}
+
+/*
+ * Given a "v8dbg_class_CLASS__FIELD__TYPE", symbol, save field "FIELD" into
+ * class CLASS with the offset described by the symbol.  Note that CLASS does
+ * not necessarily exist already.
+ */
+static int
+conf_update_field(v8_cfg_t *cfgp, const char *symbol)
+{
+	v8_class_t *clp;
+	v8_field_t *flp;
+	intptr_t offset;
+	char *pp, *qq, *tt;
+	char buf[128];
+
+	(void) strlcpy(buf, symbol, sizeof (buf));
+
+	pp = buf + sizeof ("v8dbg_class_") - 1;
+	qq = conf_next_part(buf, pp);
+
+	if (qq == NULL || (tt = conf_next_part(buf, qq)) == NULL)
+		return (-1);
+
+	if (cfgp->v8cfg_readsym(cfgp, symbol, &offset) == -1) {
+		mdb_warn("failed to read symbol \"%s\"", symbol);
+		return (-1);
+	}
+
+	if ((clp = conf_class_findcreate(pp)) == NULL ||
+	    (flp = conf_field_create(clp, qq, (size_t)offset)) == NULL)
+		return (-1);
+
+	if (strcmp(tt, "int") == 0)
+		flp->v8f_isbyte = B_TRUE;
+
+	return (0);
+}
+
+static int
+conf_update_enum(v8_cfg_t *cfgp, const char *symbol, const char *name,
+    v8_enum_t *enp)
+{
+	intptr_t value;
+
+	if (cfgp->v8cfg_readsym(cfgp, symbol, &value) == -1) {
+		mdb_warn("failed to read symbol \"%s\"", symbol);
+		return (-1);
+	}
+
+	enp->v8e_value = (int)value;
+	(void) strlcpy(enp->v8e_name, name, sizeof (enp->v8e_name));
+	return (0);
+}
+
+/*
+ * Given a "v8dbg_type_TYPENAME" constant, save the type name in v8_types.  Note
+ * that this enum has multiple integer values with the same string label.
+ */
+static int
+conf_update_type(v8_cfg_t *cfgp, const char *symbol)
+{
+	char *klass;
+	v8_enum_t *enp;
+	char buf[128];
+
+	if (v8_next_type > sizeof (v8_types) / sizeof (v8_types[0])) {
+		mdb_warn("too many V8 types\n");
+		return (-1);
+	}
+
+	(void) strlcpy(buf, symbol, sizeof (buf));
+
+	klass = buf + sizeof ("v8dbg_type_") - 1;
+	if (conf_next_part(buf, klass) == NULL)
+		return (-1);
+
+	enp = &v8_types[v8_next_type++];
+	return (conf_update_enum(cfgp, symbol, klass, enp));
+}
+
+/*
+ * Given a "v8dbg_frametype_TYPENAME" constant, save the frame type in
+ * v8_frametypes.
+ */
+static int
+conf_update_frametype(v8_cfg_t *cfgp, const char *symbol)
+{
+	const char *frametype;
+	v8_enum_t *enp;
+
+	if (v8_next_frametype >
+	    sizeof (v8_frametypes) / sizeof (v8_frametypes[0])) {
+		mdb_warn("too many V8 frame types\n");
+		return (-1);
+	}
+
+	enp = &v8_frametypes[v8_next_frametype++];
+	frametype = symbol + sizeof ("v8dbg_frametype_") - 1;
+	return (conf_update_enum(cfgp, symbol, frametype, enp));
+}
+
+/*
+ * Now that all classes have been loaded, update the "start" and "end" fields of
+ * each class based on the values of its parent class.
+ */
+static void
+conf_class_compute_offsets(v8_class_t *clp)
+{
+	v8_field_t *flp;
+
+	assert(clp->v8c_start == 0);
+	assert(clp->v8c_end == (size_t)-1);
+
+	if (clp->v8c_parent != NULL) {
+		if (clp->v8c_parent->v8c_end == (size_t)-1)
+			conf_class_compute_offsets(clp->v8c_parent);
+
+		clp->v8c_start = clp->v8c_parent->v8c_end;
+	}
+
+	if (clp->v8c_fields == NULL) {
+		clp->v8c_end = clp->v8c_start;
+		return;
+	}
+
+	for (flp = clp->v8c_fields; flp->v8f_next != NULL; flp = flp->v8f_next)
+		;
+
+	if (flp == NULL)
+		clp->v8c_end = clp->v8c_start;
+	else
+		clp->v8c_end = flp->v8f_offset + sizeof (uintptr_t);
+}
+
+/*
+ * Utility functions
+ */
+static int jsstr_print(uintptr_t, boolean_t, char **, size_t *);
+
+static const char *
+enum_lookup_str(v8_enum_t *enums, int val, const char *dflt)
+{
+	v8_enum_t *ep;
+
+	for (ep = enums; ep->v8e_name[0] != '\0'; ep++) {
+		if (ep->v8e_value == val)
+			return (ep->v8e_name);
+	}
+
+	return (dflt);
+}
+
+static void
+enum_print(v8_enum_t *enums)
+{
+	v8_enum_t *itp;
+
+	for (itp = enums; itp->v8e_name[0] != '\0'; itp++)
+		mdb_printf("%-30s = 0x%02x\n", itp->v8e_name, itp->v8e_value);
+}
+
+/*
+ * b[v]snprintf behave like [v]snprintf(3c), except that they update the buffer
+ * and length arguments based on how much buffer space is used by the operation.
+ * This makes it much easier to combine multiple calls in sequence without
+ * worrying about buffer overflow.
+ */
+static size_t
+bvsnprintf(char **bufp, size_t *buflenp, const char *format, va_list alist)
+{
+	size_t rv, len;
+
+	if (*buflenp == 0)
+		return (vsnprintf(NULL, 0, format, alist));
+
+	rv = vsnprintf(*bufp, *buflenp, format, alist);
+
+	len = MIN(rv, *buflenp);
+	*buflenp -= len;
+	*bufp += len;
+
+	return (len);
+}
+
+static size_t
+bsnprintf(char **bufp, size_t *buflenp, const char *format, ...)
+{
+	va_list alist;
+	size_t rv;
+
+	va_start(alist, format);
+	rv = bvsnprintf(bufp, buflenp, format, alist);
+	va_end(alist);
+
+	return (rv);
+}
+
+/*
+ * Returns in "offp" the offset of field "field" in C++ class "klass".
+ */
+static int
+heap_offset(const char *klass, const char *field, ssize_t *offp,
+    boolean_t silent)
+{
+	v8_class_t *clp;
+	v8_field_t *flp;
+
+	for (clp = v8_classes; clp != NULL; clp = clp->v8c_next) {
+		if (strcmp(klass, clp->v8c_name) == 0)
+			break;
+	}
+
+	if (clp == NULL) {
+		if (!silent)
+			mdb_warn("couldn't find class \"%s\"\n", klass);
+		return (-1);
+	}
+
+	for (flp = clp->v8c_fields; flp != NULL; flp = flp->v8f_next) {
+		if (strcmp(field, flp->v8f_name) == 0)
+			break;
+	}
+
+	if (flp == NULL) {
+		if (!silent)
+			mdb_warn("couldn't find class \"%s\" field \"%s\"\n",
+			    klass, field);
+		return (-1);
+	}
+
+	*offp = V8_OFF_HEAP(flp->v8f_offset);
+	return (0);
+}
+
+/*
+ * Assuming "addr" is an instance of the C++ heap class "klass", read into *valp
+ * the pointer-sized value of field "field".
+ */
+static int
+read_heap_ptr(uintptr_t *valp, uintptr_t addr, const char *klass,
+    const char *field)
+{
+	ssize_t off;
+
+	if (heap_offset(klass, field, &off, B_FALSE) != 0)
+		return (-1);
+
+	if (mdb_vread(valp, sizeof (*valp), addr + off) == -1) {
+		mdb_warn("failed to read heap value at %p", addr + off);
+		return (-1);
+	}
+
+	return (0);
+}
+
+/*
+ * Like read_heap_ptr, but assume the field is an SMI and store the actual value
+ * into *valp rather than the encoded representation.
+ */
+static int
+read_heap_smi(uintptr_t *valp, uintptr_t addr, const char *klass,
+    const char *field)
+{
+	if (read_heap_ptr(valp, addr, klass, field) != 0)
+		return (-1);
+
+	if (!V8_IS_SMI(*valp)) {
+		mdb_warn("expected SMI, got %p\n", *valp);
+		return (-1);
+	}
+
+	*valp = V8_SMI_VALUE(*valp);
+
+	return (0);
+}
+
+static int
+read_heap_double(double *valp, uintptr_t addr, const char *klass,
+    const char *field)
+{
+	ssize_t off;
+
+	if (heap_offset(klass, field, &off, B_FALSE) != 0)
+		return (-1);
+
+	if (mdb_vread(valp, sizeof (*valp), addr + off) == -1) {
+		mdb_warn("failed to read heap value at %p", addr + off);
+		return (-1);
+	}
+
+	return (0);
+}
+
+/*
+ * Assuming "addr" refers to a FixedArray, return a newly-allocated array
+ * representing its contents.
+ */
+static int
+read_heap_array(uintptr_t addr, uintptr_t **retp, size_t *lenp)
+{
+	uintptr_t len;
+
+	if (read_heap_smi(&len, addr, V8_FIXEDARRAY_BASE, "length") != 0)
+		return (-1);
+
+	*lenp = len;
+
+	if (len == 0) {
+		*retp = NULL;
+		return (0);
+	}
+
+	if ((*retp = mdb_zalloc(len * sizeof (uintptr_t), UM_GC)) == NULL)
+		return (-1);
+
+	if (mdb_vread(*retp, len * sizeof (uintptr_t),
+	    addr + V8_OFF_FIXEDARRAY_DATA) == -1)
+		return (-1);
+
+	return (0);
+}
+
+static int
+read_heap_byte(uint8_t *valp, uintptr_t addr, const char *klass,
+    const char *field)
+{
+	ssize_t off;
+
+	if (heap_offset(klass, field, &off, B_FALSE) != 0)
+		return (-1);
+
+	if (mdb_vread(valp, sizeof (*valp), addr + off) == -1) {
+		mdb_warn("failed to read heap value at %p", addr + off);
+		return (-1);
+	}
+
+	return (0);
+}
+
+/*
+ * Given a heap object, returns in *valp the byte describing the type of the
+ * object.  This is shorthand for first retrieving the Map at the start of the
+ * heap object and then retrieving the type byte from the Map object.
+ */
+static int
+read_typebyte(uint8_t *valp, uintptr_t addr)
+{
+	uintptr_t mapaddr;
+
+	if (read_heap_ptr(&mapaddr, addr, "HeapObject", "map") != 0)
+		return (-1);
+
+	if (!V8_IS_HEAPOBJECT(mapaddr)) {
+		mdb_warn("heap object map is not itself a heap object\n");
+		return (-1);
+	}
+
+	if (read_heap_byte(valp, mapaddr, "Map", "instance_attributes") == -1)
+		return (-1);
+
+	return (0);
+}
+
+/*
+ * Given a heap object, returns in *valp the size of the object.  For
+ * variable-size objects, returns an undefined value.
+ */
+static int
+read_size(size_t *valp, uintptr_t addr)
+{
+	uintptr_t mapaddr;
+	uint8_t size;
+
+	if (read_heap_ptr(&mapaddr, addr, "HeapObject", "map") != 0)
+		return (-1);
+
+	if (!V8_IS_HEAPOBJECT(mapaddr)) {
+		mdb_warn("heap object map is not itself a heap object\n");
+		return (-1);
+	}
+
+	if (read_heap_byte(&size, mapaddr, "Map", "instance_size") != 0)
+		return (-1);
+
+	*valp = size << V8_PointerSizeLog2;
+	return (0);
+}
+
+/*
+ * Returns in "buf" a description of the type of "addr" suitable for printing.
+ */
+static int
+obj_jstype(uintptr_t addr, char **bufp, size_t *lenp, uint8_t *typep)
+{
+	uint8_t typebyte;
+	uintptr_t strptr;
+	const char *typename;
+
+	if (V8_IS_FAILURE(addr)) {
+		if (typep)
+			*typep = 0;
+		(void) bsnprintf(bufp, lenp, "'Failure' object");
+		return (0);
+	}
+
+	if (V8_IS_SMI(addr)) {
+		if (typep)
+			*typep = 0;
+		(void) bsnprintf(bufp, lenp, "SMI: value = %d",
+		    V8_SMI_VALUE(addr));
+		return (0);
+	}
+
+	if (read_typebyte(&typebyte, addr) != 0)
+		return (-1);
+
+	if (typep)
+		*typep = typebyte;
+
+	typename = enum_lookup_str(v8_types, typebyte, "<unknown>");
+	(void) bsnprintf(bufp, lenp, typename);
+
+	if (strcmp(typename, "Oddball") == 0) {
+		if (read_heap_ptr(&strptr, addr, "Oddball",
+		    "to_string") != -1) {
+			(void) bsnprintf(bufp, lenp, ": \"");
+			(void) jsstr_print(strptr, B_FALSE, bufp, lenp);
+			(void) bsnprintf(bufp, lenp, "\"");
+		}
+	}
+
+	return (0);
+}
+
+/*
+ * Print out the fields of the given object that come from the given class.
+ */
+static int
+obj_print_fields(uintptr_t baddr, v8_class_t *clp)
+{
+	v8_field_t *flp;
+	uintptr_t addr, value;
+	int rv;
+	char *bufp;
+	size_t len;
+	uint8_t type;
+	char buf[256];
+
+	for (flp = clp->v8c_fields; flp != NULL; flp = flp->v8f_next) {
+		bufp = buf;
+		len = sizeof (buf);
+
+		addr = baddr + V8_OFF_HEAP(flp->v8f_offset);
+
+		if (flp->v8f_isbyte) {
+			uint8_t sv;
+			if (mdb_vread(&sv, sizeof (sv), addr) == -1) {
+				mdb_printf("%p %s (unreadable)\n",
+				    addr, flp->v8f_name);
+				continue;
+			}
+
+			mdb_printf("%p %s = 0x%x\n", addr, flp->v8f_name, sv);
+			continue;
+		}
+
+		rv = mdb_vread((void *)&value, sizeof (value), addr);
+
+		if (rv != sizeof (value) ||
+		    obj_jstype(value, &bufp, &len, &type) != 0) {
+			mdb_printf("%p %s (unreadable)\n", addr, flp->v8f_name);
+			continue;
+		}
+
+		if (type != 0 && V8_TYPE_STRING(type)) {
+			(void) bsnprintf(&bufp, &len, ": \"");
+			(void) jsstr_print(value, B_FALSE, &bufp, &len);
+			(void) bsnprintf(&bufp, &len, "\"");
+		}
+
+		mdb_printf("%p %s = %p (%s)\n", addr, flp->v8f_name, value,
+		    buf);
+	}
+
+	return (DCMD_OK);
+}
+
+/*
+ * Print out all fields of the given object, starting with the root of the class
+ * hierarchy and working down the most specific type.
+ */
+static int
+obj_print_class(uintptr_t addr, v8_class_t *clp)
+{
+	int rv = 0;
+
+	/*
+	 * If we have no fields, we just print a simple inheritance hierarchy.
+	 * If we have fields but our parent doesn't, our header includes the
+	 * inheritance hierarchy.
+	 */
+	if (clp->v8c_end == 0) {
+		mdb_printf("%s ", clp->v8c_name);
+
+		if (clp->v8c_parent != NULL) {
+			mdb_printf("< ");
+			(void) obj_print_class(addr, clp->v8c_parent);
+		}
+
+		return (0);
+	}
+
+	mdb_printf("%p %s", addr, clp->v8c_name);
+
+	if (clp->v8c_start == 0 && clp->v8c_parent != NULL) {
+		mdb_printf(" < ");
+		(void) obj_print_class(addr, clp->v8c_parent);
+	}
+
+	mdb_printf(" {\n");
+	(void) mdb_inc_indent(4);
+
+	if (clp->v8c_start > 0 && clp->v8c_parent != NULL)
+		rv = obj_print_class(addr, clp->v8c_parent);
+
+	rv |= obj_print_fields(addr, clp);
+	(void) mdb_dec_indent(4);
+	mdb_printf("}\n");
+
+	return (rv);
+}
+
+/*
+ * Print the ASCII string for the given ASCII JS string, expanding ConsStrings
+ * and ExternalStrings as needed.
+ */
+static int jsstr_print_seq(uintptr_t, boolean_t, char **, size_t *);
+static int jsstr_print_cons(uintptr_t, boolean_t, char **, size_t *);
+static int jsstr_print_external(uintptr_t, boolean_t, char **, size_t *);
+
+static int
+jsstr_print(uintptr_t addr, boolean_t verbose, char **bufp, size_t *lenp)
+{
+	uint8_t typebyte;
+	int err = 0;
+	char *lbufp;
+	size_t llen;
+	char buf[64];
+
+	if (read_typebyte(&typebyte, addr) != 0)
+		return (0);
+
+	if (!V8_TYPE_STRING(typebyte)) {
+		(void) bsnprintf(bufp, lenp, "<not a string>");
+		return (0);
+	}
+
+	if (!V8_STRENC_ASCII(typebyte)) {
+		(void) bsnprintf(bufp, lenp, "<two-byte string>");
+		return (0);
+	}
+
+	if (verbose) {
+		lbufp = buf;
+		llen = sizeof (buf);
+		(void) obj_jstype(addr, &lbufp, &llen, NULL);
+		mdb_printf("%s\n", buf);
+		(void) mdb_inc_indent(4);
+	}
+
+	if (V8_STRREP_SEQ(typebyte))
+		err = jsstr_print_seq(addr, verbose, bufp, lenp);
+	else if (V8_STRREP_CONS(typebyte))
+		err = jsstr_print_cons(addr, verbose, bufp, lenp);
+	else if (V8_STRREP_EXT(typebyte))
+		err = jsstr_print_external(addr, verbose, bufp, lenp);
+	else {
+		(void) bsnprintf(bufp, lenp, "<unknown string type>");
+		err = -1;
+	}
+
+	if (verbose)
+		(void) mdb_dec_indent(4);
+
+	return (err);
+}
+
+static int
+jsstr_print_seq(uintptr_t addr, boolean_t verbose, char **bufp, size_t *lenp)
+{
+	uintptr_t len, rlen;
+	char buf[256];
+
+	if (read_heap_smi(&len, addr, "String", "length") != 0)
+		return (-1);
+
+	rlen = len <= sizeof (buf) - 1 ? len : sizeof (buf) - sizeof ("[...]");
+
+	if (verbose)
+		mdb_printf("length: %d, will read: %d\n", len, rlen);
+
+	buf[0] = '\0';
+
+	if (rlen > 0 && mdb_readstr(buf, rlen + 1,
+	    addr + V8_OFF_SEQASCIISTR_CHARS) == -1) {
+		mdb_warn("failed to read SeqString data");
+		return (-1);
+	}
+
+	if (rlen != len)
+		(void) strlcat(buf, "[...]", sizeof (buf));
+
+	if (verbose)
+		mdb_printf("value: \"%s\"\n", buf);
+
+	(void) bsnprintf(bufp, lenp, "%s", buf);
+	return (0);
+}
+
+static int
+jsstr_print_cons(uintptr_t addr, boolean_t verbose, char **bufp, size_t *lenp)
+{
+	uintptr_t ptr1, ptr2;
+
+	if (read_heap_ptr(&ptr1, addr, "ConsString", "first") != 0 ||
+	    read_heap_ptr(&ptr2, addr, "ConsString", "second") != 0)
+		return (-1);
+
+	if (verbose) {
+		mdb_printf("ptr1: %p\n", ptr1);
+		mdb_printf("ptr2: %p\n", ptr2);
+	}
+
+	if (jsstr_print(ptr1, verbose, bufp, lenp) != 0)
+		return (-1);
+
+	return (jsstr_print(ptr2, verbose, bufp, lenp));
+}
+
+static int
+jsstr_print_external(uintptr_t addr, boolean_t verbose, char **bufp,
+    size_t *lenp)
+{
+	uintptr_t ptr1, ptr2;
+	char buf[256];
+
+	if (verbose)
+		mdb_printf("assuming Node.js string\n");
+
+	if (read_heap_ptr(&ptr1, addr, "ExternalString", "resource") != 0)
+		return (-1);
+
+	if (mdb_vread(&ptr2, sizeof (ptr2),
+	    ptr1 + NODE_OFF_EXTSTR_DATA) == -1) {
+		mdb_warn("failed to read node external pointer: %p",
+		    ptr1 + NODE_OFF_EXTSTR_DATA);
+		return (-1);
+	}
+
+	if (mdb_readstr(buf, sizeof (buf), ptr2) == -1) {
+		mdb_warn("failed to read ExternalString data");
+		return (-1);
+	}
+
+	if (buf[0] != '\0' && !isascii(buf[0])) {
+		mdb_warn("failed to read ExternalString ascii data\n");
+		return (-1);
+	}
+
+	(void) bsnprintf(bufp, lenp, "%s", buf);
+	return (0);
+}
+
+/*
+ * Returns true if the given address refers to the "undefined" object.  Returns
+ * false on failure (since we shouldn't fail on the actual "undefined" value).
+ */
+static boolean_t
+jsobj_is_undefined(uintptr_t addr)
+{
+	uint8_t type;
+	uintptr_t strptr;
+	const char *typename;
+	char buf[16];
+	char *bufp = buf;
+	size_t len = sizeof (buf);
+
+	if (read_typebyte(&type, addr) != 0)
+		return (B_FALSE);
+
+	typename = enum_lookup_str(v8_types, type, "<unknown>");
+	if (strcmp(typename, "Oddball") != 0)
+		return (B_FALSE);
+
+	if (read_heap_ptr(&strptr, addr, "Oddball", "to_string") == -1)
+		return (B_FALSE);
+
+	if (jsstr_print(strptr, B_FALSE, &bufp, &len) != 0)
+		return (B_FALSE);
+
+	return (strcmp(buf, "undefined") == 0);
+}
+
+/*
+ * Given the line endings table in "lendsp", computes the line number for the
+ * given token position and print the result into "buf".  If "lendsp" is
+ * undefined, prints the token position instead.
+ */
+static int
+jsfunc_lineno(uintptr_t lendsp, uintptr_t tokpos, char *buf, size_t buflen)
+{
+	uintptr_t size, bufsz, lower, upper, ii;
+	uintptr_t *data;
+
+	if (jsobj_is_undefined(lendsp)) {
+		mdb_snprintf(buf, buflen, "position %d", tokpos);
+		return (0);
+	}
+
+	if (read_heap_smi(&size, lendsp, V8_FIXEDARRAY_BASE, "length") != 0)
+		return (-1);
+
+	bufsz = size * sizeof (data[0]);
+
+	if ((data = mdb_alloc(bufsz, UM_NOSLEEP)) == NULL) {
+		mdb_warn("failed to alloc %d bytes for FixedArray data", bufsz);
+		return (-1);
+	}
+
+	if (mdb_vread(data, bufsz, lendsp + V8_OFF_FIXEDARRAY_DATA) != bufsz) {
+		mdb_warn("failed to read FixedArray data");
+		mdb_free(data, bufsz);
+		return (-1);
+	}
+
+	lower = 0;
+	upper = size - 1;
+
+	if (tokpos > data[upper]) {
+		(void) strlcpy(buf, "position out of range", buflen);
+		mdb_free(data, bufsz);
+		return (0);
+	}
+
+	if (tokpos <= data[0]) {
+		(void) strlcpy(buf, "line 1", buflen);
+		mdb_free(data, bufsz);
+		return (0);
+	}
+
+	while (upper >= 1) {
+		ii = (lower + upper) >> 1;
+		if (tokpos > data[ii])
+			lower = ii + 1;
+		else if (tokpos <= data[ii - 1])
+			upper = ii - 1;
+		else
+			break;
+	}
+
+	(void) mdb_snprintf(buf, buflen, "line %d", ii + 1);
+	mdb_free(data, bufsz);
+	return (0);
+}
+
+/*
+ * Given a SharedFunctionInfo object, prints into bufp a name of the function
+ * suitable for printing.  This function attempts to infer a name for anonymous
+ * functions.
+ */
+static int
+jsfunc_name(uintptr_t funcinfop, char **bufp, size_t *lenp)
+{
+	uintptr_t ptrp;
+	char *bufs = *bufp;
+
+	if (read_heap_ptr(&ptrp, funcinfop, "SharedFunctionInfo",
+	    "name") != 0 || jsstr_print(ptrp, B_FALSE, bufp, lenp) != 0)
+		return (-1);
+
+	if (*bufp != bufs)
+		return (0);
+
+	if (read_heap_ptr(&ptrp, funcinfop, "SharedFunctionInfo",
+	    "inferred_name") != 0) {
+		(void) bsnprintf(bufp, lenp, "<anonymous>");
+		return (0);
+	}
+
+	(void) bsnprintf(bufp, lenp, "<anonymous> (as ");
+	bufs = *bufp;
+
+	if (jsstr_print(ptrp, B_FALSE, bufp, lenp) != 0)
+		return (-1);
+
+	if (*bufp == bufs)
+		(void) bsnprintf(bufp, lenp, "<anon>");
+
+	(void) bsnprintf(bufp, lenp, ")");
+
+	return (0);
+}
+
+/*
+ * JavaScript-level object printing
+ */
+static int jsobj_print_number(uintptr_t, char **, size_t *);
+static int jsobj_print_oddball(uintptr_t, char **, size_t *);
+static int jsobj_print_jsobject(uintptr_t, boolean_t, int, int, char **,
+    size_t *);
+static int jsobj_print_jsarray(uintptr_t, boolean_t, int, int, char **,
+    size_t *);
+static int jsobj_print_jsfunction(uintptr_t, char **, size_t *);
+
+static int
+jsobj_print(uintptr_t addr, boolean_t printaddr, int indent, int depth,
+    char **bufp, size_t *lenp)
+{
+	uint8_t type;
+	const char *klass;
+
+	if (printaddr)
+		(void) bsnprintf(bufp, lenp, "%p: ", addr);
+
+	if (V8_IS_SMI(addr)) {
+		(void) bsnprintf(bufp, lenp, "%d", V8_SMI_VALUE(addr));
+		return (0);
+	}
+
+	if (!V8_IS_HEAPOBJECT(addr)) {
+		mdb_warn("not a heap object: %p\n", addr);
+		return (-1);
+	}
+
+	if (read_typebyte(&type, addr) != 0)
+		return (-1);
+
+	if (V8_TYPE_STRING(type))
+		return (jsstr_print(addr, B_FALSE, bufp, lenp));
+
+	klass = enum_lookup_str(v8_types, type, "<unknown>");
+	if (strcmp(klass, "HeapNumber") == 0)
+		return (jsobj_print_number(addr, bufp, lenp));
+	if (strcmp(klass, "Oddball") == 0)
+		return (jsobj_print_oddball(addr, bufp, lenp));
+	if (strcmp(klass, "JSObject") == 0)
+		return (jsobj_print_jsobject(addr, printaddr, indent, depth,
+		    bufp, lenp));
+	if (strcmp(klass, "JSArray") == 0)
+		return (jsobj_print_jsarray(addr, printaddr, indent, depth,
+		    bufp, lenp));
+	if (strcmp(klass, "JSFunction") == 0)
+		return (jsobj_print_jsfunction(addr, bufp, lenp));
+
+	mdb_warn("unknown JavaScript object type \"%s\"\n", klass);
+	return (-1);
+}
+
+static int
+jsobj_print_number(uintptr_t addr, char **bufp, size_t *lenp)
+{
+	double numval;
+
+	if (read_heap_double(&numval, addr, "HeapNumber", "value") == -1)
+		return (-1);
+
+	if (numval == (long long)numval)
+		(void) bsnprintf(bufp, lenp, "%lld", (long long)numval);
+	else
+		(void) bsnprintf(bufp, lenp, "%e", numval);
+
+	return (0);
+}
+
+static int
+jsobj_print_oddball(uintptr_t addr, char **bufp, size_t *lenp)
+{
+	uintptr_t strptr;
+
+	if (read_heap_ptr(&strptr, addr, "Oddball", "to_string") != 0)
+		return (-1);
+
+	return (jsstr_print(strptr, B_FALSE, bufp, lenp));
+}
+
+static int
+jsobj_print_jsobject(uintptr_t addr, boolean_t printaddr, int indent,
+    int depth, char **bufp, size_t *lenp)
+{
+	uintptr_t ptr, map;
+	uintptr_t *props, *descs, *content;
+	size_t ii, size, nprops, rndescs, ndescs, ncontent;
+	uint8_t type, ninprops;
+
+	if (depth == 0) {
+		(void) bsnprintf(bufp, lenp, "[...]");
+		return (0);
+	}
+
+	/*
+	 * Objects have either "fast" properties represented with a FixedArray
+	 * or slow properties represented with a Dictionary.  We only support
+	 * the former, so we check that up front.
+	 */
+	if (read_heap_ptr(&ptr, addr, "JSObject", "properties") != 0)
+		return (-1);
+
+	if (read_typebyte(&type, ptr) != 0)
+		return (-1);
+
+	if (strcmp(enum_lookup_str(v8_types, type, ""), "FixedArray") != 0) {
+		(void) bsnprintf(bufp, lenp, "{ /* unknown property */ }");
+		return (0);
+	}
+
+	if (read_heap_array(ptr, &props, &nprops) != 0)
+		return (-1);
+
+	/*
+	 * To iterate the properties, we need to examine the instance
+	 * descriptors of the associated Map object.  Some properties may be
+	 * stored inside the object itself, in which case we need to know how
+	 * big the object is and how many such properties there are.
+	 */
+	if (read_heap_ptr(&map, addr, "HeapObject", "map") != 0 ||
+	    read_heap_ptr(&ptr, map, "Map", "instance_descriptors") != 0 ||
+	    read_heap_array(ptr, &descs, &ndescs) != 0)
+		return (-1);
+
+	if (read_size(&size, addr) != 0)
+		size = 0;
+
+	if (read_heap_byte(&ninprops, map, "Map", "inobject_properties") != 0)
+		return (-1);
+
+	if (V8_PROP_IDX_CONTENT < ndescs &&
+	    read_heap_array(descs[V8_PROP_IDX_CONTENT], &content,
+	    &ncontent) != 0)
+		return (-1);
+
+	(void) bsnprintf(bufp, lenp, "{");
+
+	/*
+	 * The first FIRST (2) entries in the descriptors array are special.
+	 */
+	rndescs = ndescs <= V8_PROP_IDX_FIRST ? 0 : ndescs - V8_PROP_IDX_FIRST;
+
+	for (ii = 0; ii < rndescs; ii++) {
+		uintptr_t keyidx, validx, detidx;
+		intptr_t val;
+
+		keyidx = V8_DESC_KEYIDX(ii);
+		validx = V8_DESC_VALIDX(ii);
+		detidx = V8_DESC_DETIDX(ii);
+
+		if (detidx >= ncontent) {
+			mdb_warn("property descriptor %d: detidx (%d) "
+			    "out of bounds for content array (length %d)\n",
+			    ii, detidx, ncontent);
+			continue;
+		}
+
+		if (!V8_DESC_ISFIELD(content[detidx]))
+			continue;
+
+		if (keyidx >= ndescs) {
+			mdb_warn("property descriptor %d: keyidx (%d) "
+			    "out of bounds for descriptor array (length %d)\n",
+			    ii, keyidx, ndescs);
+			continue;
+		}
+
+		(void) bsnprintf(bufp, lenp, "\n%*s", indent + 4, "");
+		if (jsstr_print(descs[keyidx], B_FALSE, bufp, lenp) != 0)
+			continue;
+
+		(void) bsnprintf(bufp, lenp, ": ");
+
+		val = (intptr_t)content[validx];
+
+		if (!V8_IS_SMI(val)) {
+			mdb_warn("property descriptor %d: value index value "
+			    "is not an SMI: %p\n", ii, val);
+			continue;
+		}
+
+		val = V8_SMI_VALUE(val) - ninprops;
+
+		if (val < 0) {
+			/* property is stored directly in the object */
+			if (mdb_vread(&ptr, sizeof (ptr), addr + V8_OFF_HEAP(
+			    size + val * sizeof (uintptr_t))) == -1) {
+				mdb_warn("failed to read in-object "
+				    "property at %p\n", addr + V8_OFF_HEAP(
+				    size + val * sizeof (uintptr_t)));
+				continue;
+			}
+		} else {
+			/* property should be in "props" array */
+			if (val >= nprops) {
+				mdb_warn("property descriptor %d: value index "
+				    "value (%d) out of bounds (%d)\n", ii, val,
+				    nprops);
+				continue;
+			}
+
+			ptr = props[val];
+		}
+
+
+		(void) jsobj_print(ptr, printaddr, indent + 4,
+		    depth - 1, bufp, lenp);
+
+		(void) bsnprintf(bufp, lenp, ",");
+	}
+
+	if (ii > 0)
+		(void) bsnprintf(bufp, lenp, "\n%*s", indent, "");
+
+	(void) bsnprintf(bufp, lenp, "}");
+
+	return (DCMD_OK);
+}
+
+static int
+jsobj_print_jsarray(uintptr_t addr, boolean_t printaddr, int indent,
+    int depth, char **bufp, size_t *lenp)
+{
+	uintptr_t ptr;
+	uintptr_t *elts;
+	size_t ii, len;
+
+	if (depth == 0) {
+		(void) bsnprintf(bufp, lenp, "[...]");
+		return (0);
+	}
+
+	if (read_heap_ptr(&ptr, addr, "JSObject", "elements") != 0 ||
+	    read_heap_array(ptr, &elts, &len) != 0)
+		return (-1);
+
+	if (len == 0) {
+		(void) bsnprintf(bufp, lenp, "[]");
+		return (0);
+	}
+
+	if (len == 1) {
+		(void) bsnprintf(bufp, lenp, "[ ");
+		(void) jsobj_print(elts[0], printaddr, indent + 4,
+		    depth - 1, bufp, lenp);
+		(void) bsnprintf(bufp, lenp, " ]");
+		return (0);
+	}
+
+	(void) bsnprintf(bufp, lenp, "[\n");
+	for (ii = 0; ii < len; ii++) {
+		(void) bsnprintf(bufp, lenp, "%*s", indent + 4, "");
+		(void) jsobj_print(elts[ii], printaddr, indent + 4,
+		    depth - 1, bufp, lenp);
+		(void) bsnprintf(bufp, lenp, ",\n");
+	}
+
+	(void) bsnprintf(bufp, lenp, "%*s", indent, "");
+	(void) bsnprintf(bufp, lenp, "]");
+
+	return (0);
+}
+
+static int
+jsobj_print_jsfunction(uintptr_t addr, char **bufp, size_t *lenp)
+{
+	uintptr_t shared;
+
+	if (read_heap_ptr(&shared, addr, "JSFunction", "shared") != 0)
+		return (-1);
+
+	(void) bsnprintf(bufp, lenp, "function ");
+	return (jsfunc_name(shared, bufp, lenp) != 0);
+}
+
+/*
+ * dcmd implementations
+ */
+
+/* ARGSUSED */
+static int
+dcmd_v8classes(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
+{
+	v8_class_t *clp;
+
+	for (clp = v8_classes; clp != NULL; clp = clp->v8c_next)
+		mdb_printf("%s\n", clp->v8c_name);
+
+	return (DCMD_OK);
+}
+
+static void
+dcmd_v8print_help(void)
+{
+	mdb_printf(
+	    "Prints out \".\" (a V8 heap object) as an instance of its C++\n"
+	    "class.  With no arguments, the appropriate class is detected\n"
+	    "automatically.  The 'class' argument overrides this to print an\n"
+	    "object as an instance of the given class.  The list of known\n"
+	    "classes can be viewed with ::jsclasses.");
+}
+
+/* ARGSUSED */
+static int
+dcmd_v8print(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
+{
+	const char *rqclass;
+	v8_class_t *clp;
+	char *bufp;
+	size_t len;
+	uint8_t type;
+	char buf[256];
+
+	if (argc < 1) {
+		/*
+		 * If no type was specified, determine it automatically.
+		 */
+		bufp = buf;
+		len = sizeof (buf);
+		if (obj_jstype(addr, &bufp, &len, &type) != 0)
+			return (DCMD_ERR);
+
+		if (type == 0) {
+			/* For SMI or Failure, just print out the type. */
+			mdb_printf("%s\n", buf);
+			return (DCMD_OK);
+		}
+
+		if ((rqclass = enum_lookup_str(v8_types, type, NULL)) == NULL) {
+			mdb_warn("object has unknown type\n");
+			return (DCMD_ERR);
+		}
+	} else {
+		if (argv[0].a_type != MDB_TYPE_STRING)
+			return (DCMD_USAGE);
+
+		rqclass = argv[0].a_un.a_str;
+	}
+
+	for (clp = v8_classes; clp != NULL; clp = clp->v8c_next) {
+		if (strcmp(rqclass, clp->v8c_name) == 0)
+			break;
+	}
+
+	if (clp == NULL) {
+		mdb_warn("unknown class '%s'\n", rqclass);
+		return (DCMD_USAGE);
+	}
+
+	return (obj_print_class(addr, clp));
+}
+
+/* ARGSUSED */
+static int
+dcmd_v8type(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
+{
+	char buf[64];
+	char *bufp = buf;
+	size_t len = sizeof (buf);
+
+	if (obj_jstype(addr, &bufp, &len, NULL) != 0)
+		return (DCMD_ERR);
+
+	mdb_printf("0x%p: %s\n", addr, buf);
+	return (DCMD_OK);
+}
+
+/* ARGSUSED */
+static int
+dcmd_v8types(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
+{
+	enum_print(v8_types);
+	return (DCMD_OK);
+}
+
+/* ARGSUSED */
+static int
+dcmd_jsframe(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
+{
+	uintptr_t ftype, funcp, funcinfop, tokpos, scriptp, lendsp, ptrp;
+	uintptr_t ii, nargs;
+	boolean_t opt_v = B_FALSE;
+	char typebuf[256];
+	char funcname[64];
+	char *bufp;
+	size_t len;
+
+	if (mdb_getopts(argc, argv, 'v', MDB_OPT_SETBITS, B_TRUE, &opt_v,
+	    NULL) != argc)
+		return (DCMD_USAGE);
+
+	/*
+	 * First figure out what kind of frame this is using the same algorithm
+	 * as V8's ComputeType function.  We only print useful information for
+	 * JavaScriptFrames.  Conveniently, most other frame types are indicated
+	 * by the presence of a frame type identifier on the stack.  For
+	 * ArgumentsAdaptorFrames, the type identifier is in the "context" slot,
+	 * while for other frames the type identifier is in the "marker" slot.
+	 * Like V8, we check for the AdaptorFrame first, then look for other
+	 * types, and if we haven't found a frame type identifier then we assume
+	 * we're looking at a JavaScriptFrame.
+	 */
+	if (mdb_vread(&ftype, sizeof (ftype), addr + V8_OFF_FP_CONTEXT) == -1)
+		return (DCMD_ERR);
+
+	if (!V8_IS_SMI(ftype) &&
+	    mdb_vread(&ftype, sizeof (ftype), addr + V8_OFF_FP_MARKER) == -1)
+		return (DCMD_ERR);
+
+	if (V8_IS_SMI(ftype)) {
+		mdb_printf("%p <%s>\n", addr, enum_lookup_str(
+		    v8_frametypes, V8_SMI_VALUE(ftype), "<unknown>"));
+		return (DCMD_OK);
+	}
+
+	if (mdb_vread(&funcp, sizeof (funcp), addr + V8_OFF_FP_FUNCTION) == -1)
+		return (DCMD_ERR);
+
+	if (read_heap_ptr(&funcinfop, funcp, "JSFunction", "shared") != 0)
+		return (DCMD_ERR);
+
+	bufp = funcname;
+	len = sizeof (funcname);
+	if (jsfunc_name(funcinfop, &bufp, &len) != 0)
+		return (DCMD_ERR);
+
+	mdb_printf("%p %s", addr, funcname);
+
+	/*
+	 * Although the token position is technically an SMI, we're going to
+	 * byte-compare it to other SMI values so we don't want decode it here.
+	 */
+	if (read_heap_ptr(&tokpos, funcinfop,
+	    "SharedFunctionInfo", "function_token_position") != 0)
+		return (DCMD_ERR);
+
+	if (read_heap_ptr(&scriptp, funcinfop,
+	    "SharedFunctionInfo", "script") != 0)
+		return (DCMD_ERR);
+
+	if (read_heap_ptr(&ptrp, scriptp, "Script", "name") != 0)
+		return (DCMD_ERR);
+
+	bufp = typebuf;
+	len = sizeof (typebuf);
+	(void) jsstr_print(ptrp, B_FALSE, &bufp, &len);
+
+	if (opt_v) {
+		mdb_printf("\n");
+		(void) mdb_inc_indent(4);
+		mdb_printf("func: %p\n", funcp);
+		mdb_printf("file: %s\n", typebuf);
+	} else {
+		mdb_printf(" at %s ", typebuf);
+	}
+
+	if (read_heap_ptr(&lendsp, scriptp, "Script", "line_ends") != 0)
+		return (DCMD_ERR);
+
+	(void) jsfunc_lineno(lendsp, tokpos, typebuf, sizeof (typebuf));
+
+	if (opt_v)
+		mdb_printf("posn: %s\n", typebuf);
+	else
+		mdb_printf("%s\n", typebuf);
+
+	if (opt_v) {
+		if (read_heap_smi(&nargs, funcinfop,
+		    "SharedFunctionInfo", "length") == 0) {
+			for (ii = 0; ii < nargs; ii++) {
+				uintptr_t argptr;
+
+				if (mdb_vread(&argptr, sizeof (argptr),
+				    addr + V8_OFF_FP_ARGS + (nargs - ii - 1) *
+				    sizeof (uintptr_t)) == -1)
+					continue;
+
+				bufp = typebuf;
+				len = sizeof (typebuf);
+				(void) obj_jstype(argptr, &bufp, &len, NULL);
+
+				mdb_printf("arg%d: %p (%s)\n", (ii + 1),
+				    argptr, typebuf);
+			}
+		}
+
+		(void) mdb_dec_indent(4);
+	}
+
+	return (DCMD_OK);
+}
+
+/* ARGSUSED */
+static int
+dcmd_jsprint(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
+{
+	char *buf;
+	char *bufp;
+	size_t len, bufsz = 262144;
+	boolean_t verbose;
+	uint64_t depth;
+	int rv;
+
+	verbose = B_FALSE;
+	depth = 2;
+
+	if (mdb_getopts(argc, argv,
+	    'a', MDB_OPT_SETBITS, B_TRUE, &verbose,
+	    'd', MDB_OPT_UINT64, &depth, NULL) != argc)
+		return (DCMD_USAGE);
+
+	if ((buf = mdb_zalloc(bufsz, UM_NOSLEEP)) == NULL)
+		return (DCMD_ERR);
+
+	bufp = buf;
+	len = bufsz;
+	rv = jsobj_print(addr, verbose, 0, (int)depth, &bufp, &len);
+	(void) mdb_printf("%s\n", buf);
+	mdb_free(buf, bufsz);
+	return (rv == 0 ? DCMD_OK : DCMD_ERR);
+}
+
+/* ARGSUSED */
+static int
+dcmd_v8array(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
+{
+	uint8_t type;
+	uintptr_t *array;
+	size_t ii, len;
+
+	if (read_typebyte(&type, addr) != 0)
+		return (DCMD_ERR);
+
+	if (strcmp(enum_lookup_str(v8_types, type, ""), "FixedArray") != 0) {
+		mdb_warn("%p is not an instance of FixedArray\n", addr);
+		return (DCMD_ERR);
+	}
+
+	if (read_heap_array(addr, &array, &len) != 0)
+		return (DCMD_ERR);
+
+	for (ii = 0; ii < len; ii++)
+		mdb_printf("%p\n", array[ii]);
+
+	return (DCMD_OK);
+}
+
+/* ARGSUSED */
+static int
+dcmd_jsstack(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
+{
+	if (mdb_walk_dcmd("jsframe", "jsframe", argc, argv) == -1)
+		return (DCMD_ERR);
+
+	return (DCMD_OK);
+}
+
+/* ARGSUSED */
+static int
+dcmd_v8str(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
+{
+	boolean_t opt_v = B_FALSE;
+	char buf[256];
+	char *bufp;
+	size_t len;
+
+	if (mdb_getopts(argc, argv, 'v', MDB_OPT_SETBITS, B_TRUE, &opt_v,
+	    NULL) != argc)
+		return (DCMD_USAGE);
+
+	bufp = buf;
+	len = sizeof (buf);
+	if (jsstr_print(addr, opt_v, &bufp, &len) != 0)
+		return (DCMD_ERR);
+
+	mdb_printf("%s\n", buf);
+	return (DCMD_OK);
+}
+
+static void
+dcmd_v8load_help(void)
+{
+	v8_cfg_t *cfp;
+
+	mdb_printf(
+	    "To traverse in-memory V8 structures, the V8 dmod requires\n"
+	    "configuration that describes the layout of various V8 structures\n"
+	    "in memory.  Normally, this information is pulled from metadata\n"
+	    "in the target binary.  However, it's possible to use the module\n"
+	    "with a binary not built with metadata by loading one of the\n"
+	    "canned configurations.\n\n");
+
+	mdb_printf("Available configurations:\n");
+
+	(void) mdb_inc_indent(4);
+
+	for (cfp = v8_cfgs; cfp->v8cfg_name != NULL; cfp++)
+		mdb_printf("%-10s    %s\n", cfp->v8cfg_name, cfp->v8cfg_label);
+
+	(void) mdb_dec_indent(4);
+}
+
+/* ARGSUSED */
+static int
+dcmd_v8load(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
+{
+	v8_cfg_t *cfgp;
+
+	if (v8_classes != NULL) {
+		mdb_warn("v8 module already configured\n");
+		return (DCMD_ERR);
+	}
+
+	if (argc < 1 || argv->a_type != MDB_TYPE_STRING)
+		return (DCMD_USAGE);
+
+	for (cfgp = v8_cfgs; cfgp->v8cfg_name != NULL; cfgp++) {
+		if (strcmp(argv->a_un.a_str, cfgp->v8cfg_name) == 0)
+			break;
+	}
+
+	if (cfgp->v8cfg_name == NULL) {
+		mdb_warn("unknown configuration: \"%s\"\n", argv->a_un.a_str);
+		return (DCMD_ERR);
+	}
+
+	if (autoconfigure(cfgp) == -1) {
+		mdb_warn("autoconfigure failed\n");
+		return (DCMD_ERR);
+	}
+
+	mdb_printf("V8 dmod configured based on %s\n", cfgp->v8cfg_name);
+	return (DCMD_OK);
+}
+
+static int
+walk_jsframes_init(mdb_walk_state_t *wsp)
+{
+	mdb_tid_t tid;
+	mdb_reg_t reg;
+
+	tid = wsp->walk_addr != NULL ?
+	    (mdb_tid_t)wsp->walk_addr : 1;
+
+	if (mdb_getareg(tid, "ebp", &reg) != 0) {
+		mdb_warn("failed to read ebp for thread %d", tid);
+		return (WALK_ERR);
+	}
+
+	wsp->walk_addr = (uintptr_t)reg;
+	return (WALK_NEXT);
+}
+
+static int
+walk_jsframes_step(mdb_walk_state_t *wsp)
+{
+	uintptr_t ftype, addr, next;
+	int rv;
+
+	addr = wsp->walk_addr;
+	rv = wsp->walk_callback(wsp->walk_addr, NULL, wsp->walk_cbdata);
+
+	if (rv != WALK_NEXT)
+		return (rv);
+
+	/*
+	 * Figure out the type of this frame.
+	 */
+	if (mdb_vread(&ftype, sizeof (ftype), addr + V8_OFF_FP_MARKER) == -1)
+		return (WALK_ERR);
+
+	if (V8_IS_SMI(ftype) && V8_SMI_VALUE(ftype) == 0)
+		return (WALK_DONE);
+
+	if (mdb_vread(&next, sizeof (next), addr) == -1)
+		return (WALK_ERR);
+
+	wsp->walk_addr = next;
+	return (WALK_NEXT);
+}
+
+/*
+ * MDB linkage
+ */
+
+static const mdb_dcmd_t v8_mdb_dcmds[] = {
+	/*
+	 * Commands to inspect JavaScript-level state
+	 */
+	{ "jsframe", ":[-v]", "summarize a JavaScript stack frame",
+		dcmd_jsframe },
+	{ "jsprint", ":[-a] [-d depth]", "print a JavaScript object",
+		dcmd_jsprint },
+	{ "jsstack", "[-v]", "print a JavaScript stacktrace",
+		dcmd_jsstack },
+
+	/*
+	 * Commands to inspect V8-level state
+	 */
+	{ "v8array", ":", "print elements of a V8 FixedArray",
+		dcmd_v8array },
+	{ "v8classes", NULL, "list known V8 heap object C++ classes",
+		dcmd_v8classes },
+	{ "v8load", "version", "load canned config for a specific V8 version",
+		dcmd_v8load, dcmd_v8load_help },
+	{ "v8print", ":[class]", "print a V8 heap object",
+		dcmd_v8print, dcmd_v8print_help },
+	{ "v8str", ":[-v]", "print the contents of a V8 string",
+		dcmd_v8str },
+	{ "v8type", ":", "print the type of a V8 heap object",
+		dcmd_v8type },
+	{ "v8types", NULL, "list known V8 heap object types",
+		dcmd_v8types },
+
+	{ NULL }
+};
+
+static const mdb_walker_t v8_mdb_walkers[] = {
+	{ "jsframe", "walk V8 JavaScript stack frames",
+		walk_jsframes_init, walk_jsframes_step },
+	{ NULL }
+};
+
+static mdb_modinfo_t v8_mdb = { MDB_API_VERSION, v8_mdb_dcmds, v8_mdb_walkers };
+
+const mdb_modinfo_t *
+_mdb_init(void)
+{
+	GElf_Sym sym;
+
+	/*
+	 * Do a quick check first for debug metadata included in the binary.  If
+	 * it's there, we autoconfigure based on this metadata.  If not, we
+	 * assume this is not a V8 binary and there's nothing for us to do.  If
+	 * there's no metadata but this really is V8, the user can attempt to
+	 * load a canned configuration using ::v8load.
+	 */
+	if (mdb_lookup_by_name("v8dbg_SmiTag", &sym) == 0) {
+		if (autoconfigure(&v8_cfg_target) != 0)
+			mdb_warn("failed to autoconfigure from target\n");
+		else
+			mdb_printf("Loaded V8 support.\n");
+	}
+
+	return (&v8_mdb);
+}
diff --git a/usr/src/cmd/mdb/common/modules/v8/mdb_v8_cfg.c b/usr/src/cmd/mdb/common/modules/v8/mdb_v8_cfg.c
new file mode 100644
index 0000000000..05d25b65d6
--- /dev/null
+++ b/usr/src/cmd/mdb/common/modules/v8/mdb_v8_cfg.c
@@ -0,0 +1,715 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2011, Joyent, Inc. All rights reserved.
+ */
+
+/*
+ * mdb_v8_cfg.c: canned configurations for previous V8 versions.
+ *
+ * The functions and data defined here enable this dmod to support debugging
+ * Node.js binaries that predated V8's built-in postmortem debugging support.
+ */
+
+#include "v8cfg.h"
+
+/*ARGSUSED*/
+static int
+v8cfg_target_iter(v8_cfg_t *cfgp, int (*func)(mdb_symbol_t *, void *),
+    void *arg)
+{
+	return (mdb_symbol_iter(MDB_OBJ_EVERY, MDB_SYMTAB,
+	    MDB_BIND_GLOBAL | MDB_TYPE_OBJECT | MDB_TYPE_FUNC,
+	    func, arg));
+}
+
+/*ARGSUSED*/
+static int
+v8cfg_target_readsym(v8_cfg_t *cfgp, const char *name, intptr_t *valp)
+{
+	return (mdb_readsym(valp, sizeof (valp), name));
+}
+
+/*
+ * Analog of mdb_symbol_iter() for a canned configuration.
+ */
+static int
+v8cfg_canned_iter(v8_cfg_t *cfgp, int (*func)(mdb_symbol_t *, void *),
+    void *arg)
+{
+	v8_cfg_symbol_t *v8sym;
+	mdb_symbol_t mdbsym;
+	int rv;
+
+	for (v8sym = cfgp->v8cfg_symbols; v8sym->v8cs_name != NULL; v8sym++) {
+		mdbsym.sym_name = v8sym->v8cs_name;
+		mdbsym.sym_object = NULL;
+		mdbsym.sym_sym = NULL;
+		mdbsym.sym_table = 0;
+		mdbsym.sym_id = 0;
+
+		if ((rv = func(&mdbsym, arg)) != 0)
+			return (rv);
+	}
+
+	return (0);
+}
+
+/*
+ * Analog of mdb_readsym() for a canned configuration.
+ */
+static int
+v8cfg_canned_readsym(v8_cfg_t *cfgp, const char *name, intptr_t *valp)
+{
+	v8_cfg_symbol_t *v8sym;
+
+	for (v8sym = cfgp->v8cfg_symbols; v8sym->v8cs_name != NULL; v8sym++) {
+		if (strcmp(name, v8sym->v8cs_name) == 0)
+			break;
+	}
+
+	if (v8sym->v8cs_name == NULL) {
+		mdb_warn("no such canned symbol: %s\n", name);
+		return (-1);
+	}
+
+	*valp = v8sym->v8cs_value;
+	return (0);
+}
+
+/*
+ * Canned configuration for the V8 bundled with Node.js v0.4.8 and later.
+ */
+static v8_cfg_symbol_t v8_cfg_node_04[] = {
+	{ "v8dbg_type_AccessCheckInfo__ACCESS_CHECK_INFO_TYPE", 0x91 },
+	{ "v8dbg_type_AccessorInfo__ACCESSOR_INFO_TYPE", 0x90 },
+	{ "v8dbg_type_BreakPointInfo__BREAK_POINT_INFO_TYPE", 0x9b },
+	{ "v8dbg_type_ByteArray__BYTE_ARRAY_TYPE", 0x86 },
+	{ "v8dbg_type_CallHandlerInfo__CALL_HANDLER_INFO_TYPE", 0x93 },
+	{ "v8dbg_type_Code__CODE_TYPE", 0x81 },
+	{ "v8dbg_type_CodeCache__CODE_CACHE_TYPE", 0x99 },
+	{ "v8dbg_type_ConsString__CONS_ASCII_STRING_TYPE", 0x5 },
+	{ "v8dbg_type_ConsString__CONS_ASCII_SYMBOL_TYPE", 0x45 },
+	{ "v8dbg_type_ConsString__CONS_STRING_TYPE", 0x1 },
+	{ "v8dbg_type_ConsString__CONS_SYMBOL_TYPE", 0x41 },
+	{ "v8dbg_type_DebugInfo__DEBUG_INFO_TYPE", 0x9a },
+	{ "v8dbg_type_ExternalAsciiString__EXTERNAL_ASCII_STRING_TYPE", 0x6 },
+	{ "v8dbg_type_ExternalAsciiString__EXTERNAL_ASCII_SYMBOL_TYPE", 0x46 },
+	{ "v8dbg_type_ExternalByteArray__EXTERNAL_BYTE_ARRAY_TYPE", 0x88 },
+	{ "v8dbg_type_ExternalFloatArray__EXTERNAL_FLOAT_ARRAY_TYPE", 0x8e },
+	{ "v8dbg_type_ExternalIntArray__EXTERNAL_INT_ARRAY_TYPE", 0x8c },
+	{ "v8dbg_type_ExternalShortArray__EXTERNAL_SHORT_ARRAY_TYPE", 0x8a },
+	{ "v8dbg_type_ExternalString__EXTERNAL_STRING_TYPE", 0x2 },
+	{ "v8dbg_type_ExternalString__EXTERNAL_SYMBOL_TYPE", 0x42 },
+	{ "v8dbg_type_ExternalUnsignedByteArray__"
+		"EXTERNAL_UNSIGNED_BYTE_ARRAY_TYPE", 0x89 },
+	{ "v8dbg_type_ExternalUnsignedIntArray__"
+		"EXTERNAL_UNSIGNED_INT_ARRAY_TYPE", 0x8d },
+	{ "v8dbg_type_ExternalUnsignedShortArray__"
+		"EXTERNAL_UNSIGNED_SHORT_ARRAY_TYPE", 0x8b },
+	{ "v8dbg_type_FixedArray__FIXED_ARRAY_TYPE", 0x9c },
+	{ "v8dbg_type_FunctionTemplateInfo__"
+		"FUNCTION_TEMPLATE_INFO_TYPE", 0x94 },
+	{ "v8dbg_type_HeapNumber__HEAP_NUMBER_TYPE", 0x84 },
+	{ "v8dbg_type_InterceptorInfo__INTERCEPTOR_INFO_TYPE", 0x92 },
+	{ "v8dbg_type_JSArray__JS_ARRAY_TYPE", 0xa5 },
+	{ "v8dbg_type_JSBuiltinsObject__JS_BUILTINS_OBJECT_TYPE", 0xa3 },
+	{ "v8dbg_type_JSFunction__JS_FUNCTION_TYPE", 0xa7 },
+	{ "v8dbg_type_JSGlobalObject__JS_GLOBAL_OBJECT_TYPE", 0xa2 },
+	{ "v8dbg_type_JSGlobalPropertyCell__"
+		"JS_GLOBAL_PROPERTY_CELL_TYPE", 0x83 },
+	{ "v8dbg_type_JSGlobalProxy__JS_GLOBAL_PROXY_TYPE", 0xa4 },
+	{ "v8dbg_type_JSMessageObject__JS_MESSAGE_OBJECT_TYPE", 0x9e },
+	{ "v8dbg_type_JSObject__JS_OBJECT_TYPE", 0xa0 },
+	{ "v8dbg_type_JSRegExp__JS_REGEXP_TYPE", 0xa6 },
+	{ "v8dbg_type_JSValue__JS_VALUE_TYPE", 0x9f },
+	{ "v8dbg_type_Map__MAP_TYPE", 0x80 },
+	{ "v8dbg_type_ObjectTemplateInfo__OBJECT_TEMPLATE_INFO_TYPE", 0x95 },
+	{ "v8dbg_type_Oddball__ODDBALL_TYPE", 0x82 },
+	{ "v8dbg_type_Script__SCRIPT_TYPE", 0x98 },
+	{ "v8dbg_type_SeqAsciiString__ASCII_STRING_TYPE", 0x4 },
+	{ "v8dbg_type_SeqAsciiString__ASCII_SYMBOL_TYPE", 0x44 },
+	{ "v8dbg_type_SharedFunctionInfo__SHARED_FUNCTION_INFO_TYPE", 0x9d },
+	{ "v8dbg_type_SignatureInfo__SIGNATURE_INFO_TYPE", 0x96 },
+	{ "v8dbg_type_String__STRING_TYPE", 0x0 },
+	{ "v8dbg_type_String__SYMBOL_TYPE", 0x40 },
+	{ "v8dbg_type_TypeSwitchInfo__TYPE_SWITCH_INFO_TYPE", 0x97 },
+
+	{ "v8dbg_class_AccessCheckInfo__data__Object", 0xc },
+	{ "v8dbg_class_AccessCheckInfo__indexed_callback__Object", 0x8 },
+	{ "v8dbg_class_AccessCheckInfo__named_callback__Object", 0x4 },
+	{ "v8dbg_class_AccessorInfo__data__Object", 0xc },
+	{ "v8dbg_class_AccessorInfo__flag__Smi", 0x14 },
+	{ "v8dbg_class_AccessorInfo__getter__Object", 0x4 },
+	{ "v8dbg_class_AccessorInfo__name__Object", 0x10 },
+	{ "v8dbg_class_AccessorInfo__setter__Object", 0x8 },
+	{ "v8dbg_class_BreakPointInfo__break_point_objects__Object", 0x10 },
+	{ "v8dbg_class_BreakPointInfo__code_position__Smi", 0x4 },
+	{ "v8dbg_class_BreakPointInfo__source_position__Smi", 0x8 },
+	{ "v8dbg_class_BreakPointInfo__statement_position__Smi", 0xc },
+	{ "v8dbg_class_ByteArray__length__SMI", 0x4 },
+	{ "v8dbg_class_CallHandlerInfo__callback__Object", 0x4 },
+	{ "v8dbg_class_CallHandlerInfo__data__Object", 0x8 },
+	{ "v8dbg_class_Code__deoptimization_data__FixedArray", 0xc },
+	{ "v8dbg_class_Code__relocation_info__ByteArray", 0x8 },
+	{ "v8dbg_class_CodeCache__default_cache__FixedArray", 0x4 },
+	{ "v8dbg_class_CodeCache__normal_type_cache__Object", 0x8 },
+	{ "v8dbg_class_ConsString__first__String", 0xc },
+	{ "v8dbg_class_ConsString__second__String", 0x10 },
+	{ "v8dbg_class_DebugInfo__break_points__FixedArray", 0x14 },
+	{ "v8dbg_class_DebugInfo__code__Code", 0xc },
+	{ "v8dbg_class_DebugInfo__original_code__Code", 0x8 },
+	{ "v8dbg_class_DebugInfo__shared__SharedFunctionInfo", 0x4 },
+	{ "v8dbg_class_ExternalString__resource__Object", 0xc },
+	{ "v8dbg_class_FixedArray__data__uintptr_t", 0x8 },
+	{ "v8dbg_class_FixedArray__length__SMI", 0x4 },
+	{ "v8dbg_class_FunctionTemplateInfo__access_check_info__Object", 0x38 },
+	{ "v8dbg_class_FunctionTemplateInfo__call_code__Object", 0x10 },
+	{ "v8dbg_class_FunctionTemplateInfo__class_name__Object", 0x2c },
+	{ "v8dbg_class_FunctionTemplateInfo__flag__Smi", 0x3c },
+	{ "v8dbg_class_FunctionTemplateInfo__"
+		"indexed_property_handler__Object", 0x24 },
+	{ "v8dbg_class_FunctionTemplateInfo__"
+		"instance_call_handler__Object", 0x34 },
+	{ "v8dbg_class_FunctionTemplateInfo__instance_template__Object", 0x28 },
+	{ "v8dbg_class_FunctionTemplateInfo__"
+		"named_property_handler__Object", 0x20 },
+	{ "v8dbg_class_FunctionTemplateInfo__parent_template__Object", 0x1c },
+	{ "v8dbg_class_FunctionTemplateInfo__"
+		"property_accessors__Object", 0x14 },
+	{ "v8dbg_class_FunctionTemplateInfo__"
+		"prototype_template__Object", 0x18 },
+	{ "v8dbg_class_FunctionTemplateInfo__serial_number__Object", 0xc },
+	{ "v8dbg_class_FunctionTemplateInfo__signature__Object", 0x30 },
+	{ "v8dbg_class_GlobalObject__builtins__JSBuiltinsObject", 0xc },
+	{ "v8dbg_class_GlobalObject__global_context__Context", 0x10 },
+	{ "v8dbg_class_GlobalObject__global_receiver__JSObject", 0x14 },
+	{ "v8dbg_class_HeapNumber__value__SMI", 0x4 },
+	{ "v8dbg_class_HeapObject__map__Map", 0x0 },
+	{ "v8dbg_class_InterceptorInfo__data__Object", 0x18 },
+	{ "v8dbg_class_InterceptorInfo__deleter__Object", 0x10 },
+	{ "v8dbg_class_InterceptorInfo__enumerator__Object", 0x14 },
+	{ "v8dbg_class_InterceptorInfo__getter__Object", 0x4 },
+	{ "v8dbg_class_InterceptorInfo__query__Object", 0xc },
+	{ "v8dbg_class_InterceptorInfo__setter__Object", 0x8 },
+	{ "v8dbg_class_JSArray__length__Object", 0xc },
+	{ "v8dbg_class_JSFunction__literals__FixedArray", 0x1c },
+	{ "v8dbg_class_JSFunction__next_function_link__Object", 0x20 },
+	{ "v8dbg_class_JSFunction__prototype_or_initial_map__Object", 0x10 },
+	{ "v8dbg_class_JSFunction__shared__SharedFunctionInfo", 0x14 },
+	{ "v8dbg_class_JSGlobalProxy__context__Object", 0xc },
+	{ "v8dbg_class_JSMessageObject__arguments__JSArray", 0x10 },
+	{ "v8dbg_class_JSMessageObject__end_position__SMI", 0x24 },
+	{ "v8dbg_class_JSMessageObject__script__Object", 0x14 },
+	{ "v8dbg_class_JSMessageObject__stack_frames__Object", 0x1c },
+	{ "v8dbg_class_JSMessageObject__stack_trace__Object", 0x18 },
+	{ "v8dbg_class_JSMessageObject__start_position__SMI", 0x20 },
+	{ "v8dbg_class_JSMessageObject__type__String", 0xc },
+	{ "v8dbg_class_JSObject__elements__Object", 0x8 },
+	{ "v8dbg_class_JSObject__properties__FixedArray", 0x4 },
+	{ "v8dbg_class_JSRegExp__data__Object", 0xc },
+	{ "v8dbg_class_JSValue__value__Object", 0xc },
+	{ "v8dbg_class_Map__code_cache__Object", 0x18 },
+	{ "v8dbg_class_Map__constructor__Object", 0x10 },
+	{ "v8dbg_class_Map__inobject_properties__int", 0x5 },
+	{ "v8dbg_class_Map__instance_size__int", 0x4 },
+	{ "v8dbg_class_Map__instance_attributes__int", 0x8 },
+	{ "v8dbg_class_Map__instance_descriptors__DescriptorArray", 0x14 },
+	{ "v8dbg_class_ObjectTemplateInfo__constructor__Object", 0xc },
+	{ "v8dbg_class_ObjectTemplateInfo__"
+		"internal_field_count__Object", 0x10 },
+	{ "v8dbg_class_Oddball__to_number__Object", 0x8 },
+	{ "v8dbg_class_Oddball__to_string__String", 0x4 },
+	{ "v8dbg_class_Script__column_offset__Smi", 0x10 },
+	{ "v8dbg_class_Script__compilation_type__Smi", 0x24 },
+	{ "v8dbg_class_Script__context_data__Object", 0x18 },
+	{ "v8dbg_class_Script__data__Object", 0x14 },
+	{ "v8dbg_class_Script__eval_from_instructions_offset__Smi", 0x34 },
+	{ "v8dbg_class_Script__eval_from_shared__Object", 0x30 },
+	{ "v8dbg_class_Script__id__Object", 0x2c },
+	{ "v8dbg_class_Script__line_ends__Object", 0x28 },
+	{ "v8dbg_class_Script__line_offset__Smi", 0xc },
+	{ "v8dbg_class_Script__name__Object", 0x8 },
+	{ "v8dbg_class_Script__source__Object", 0x4 },
+	{ "v8dbg_class_Script__type__Smi", 0x20 },
+	{ "v8dbg_class_Script__wrapper__Proxy", 0x1c },
+	{ "v8dbg_class_SeqAsciiString__chars__char", 0xc },
+	{ "v8dbg_class_SharedFunctionInfo__compiler_hints__SMI", 0x50 },
+	{ "v8dbg_class_SharedFunctionInfo__construct_stub__Code", 0x10 },
+	{ "v8dbg_class_SharedFunctionInfo__debug_info__Object", 0x20 },
+	{ "v8dbg_class_SharedFunctionInfo__end_position__SMI", 0x48 },
+	{ "v8dbg_class_SharedFunctionInfo__"
+		"expected_nof_properties__SMI", 0x3c },
+	{ "v8dbg_class_SharedFunctionInfo__formal_parameter_count__SMI", 0x38 },
+	{ "v8dbg_class_SharedFunctionInfo__function_data__Object", 0x18 },
+	{ "v8dbg_class_SharedFunctionInfo__"
+		"function_token_position__SMI", 0x4c },
+	{ "v8dbg_class_SharedFunctionInfo__inferred_name__String", 0x24 },
+	{ "v8dbg_class_SharedFunctionInfo__initial_map__Object", 0x28 },
+	{ "v8dbg_class_SharedFunctionInfo__instance_class_name__Object", 0x14 },
+	{ "v8dbg_class_SharedFunctionInfo__length__SMI", 0x34 },
+	{ "v8dbg_class_SharedFunctionInfo__name__Object", 0x4 },
+	{ "v8dbg_class_SharedFunctionInfo__num_literals__SMI", 0x40 },
+	{ "v8dbg_class_SharedFunctionInfo__opt_count__SMI", 0x58 },
+	{ "v8dbg_class_SharedFunctionInfo__script__Object", 0x1c },
+	{ "v8dbg_class_SharedFunctionInfo__"
+		"start_position_and_type__SMI", 0x44 },
+	{ "v8dbg_class_SharedFunctionInfo__"
+		"this_property_assignments__Object", 0x2c },
+	{ "v8dbg_class_SharedFunctionInfo__"
+		"this_property_assignments_count__SMI", 0x54 },
+	{ "v8dbg_class_SignatureInfo__args__Object", 0x8 },
+	{ "v8dbg_class_SignatureInfo__receiver__Object", 0x4 },
+	{ "v8dbg_class_String__length__SMI", 0x4 },
+	{ "v8dbg_class_TemplateInfo__property_list__Object", 0x8 },
+	{ "v8dbg_class_TemplateInfo__tag__Object", 0x4 },
+	{ "v8dbg_class_TypeSwitchInfo__types__Object", 0x4 },
+
+	{ "v8dbg_parent_AccessCheckInfo__Struct", 0x0 },
+	{ "v8dbg_parent_AccessorInfo__Struct", 0x0 },
+	{ "v8dbg_parent_BreakPointInfo__Struct", 0x0 },
+	{ "v8dbg_parent_ByteArray__HeapObject", 0x0 },
+	{ "v8dbg_parent_CallHandlerInfo__Struct", 0x0 },
+	{ "v8dbg_parent_Code__HeapObject", 0x0 },
+	{ "v8dbg_parent_CodeCache__Struct", 0x0 },
+	{ "v8dbg_parent_ConsString__String", 0x0 },
+	{ "v8dbg_parent_DebugInfo__Struct", 0x0 },
+	{ "v8dbg_parent_DeoptimizationInputData__FixedArray", 0x0 },
+	{ "v8dbg_parent_DeoptimizationOutputData__FixedArray", 0x0 },
+	{ "v8dbg_parent_DescriptorArray__FixedArray", 0x0 },
+	{ "v8dbg_parent_ExternalArray__HeapObject", 0x0 },
+	{ "v8dbg_parent_ExternalAsciiString__ExternalString", 0x0 },
+	{ "v8dbg_parent_ExternalByteArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_ExternalFloatArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_ExternalIntArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_ExternalShortArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_ExternalString__String", 0x0 },
+	{ "v8dbg_parent_ExternalTwoByteString__ExternalString", 0x0 },
+	{ "v8dbg_parent_ExternalUnsignedByteArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_ExternalUnsignedIntArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_ExternalUnsignedShortArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_Failure__MaybeObject", 0x0 },
+	{ "v8dbg_parent_FixedArray__HeapObject", 0x0 },
+	{ "v8dbg_parent_FunctionTemplateInfo__TemplateInfo", 0x0 },
+	{ "v8dbg_parent_GlobalObject__JSObject", 0x0 },
+	{ "v8dbg_parent_HeapNumber__HeapObject", 0x0 },
+	{ "v8dbg_parent_HeapObject__Object", 0x0 },
+	{ "v8dbg_parent_InterceptorInfo__Struct", 0x0 },
+	{ "v8dbg_parent_JSArray__JSObject", 0x0 },
+	{ "v8dbg_parent_JSBuiltinsObject__GlobalObject", 0x0 },
+	{ "v8dbg_parent_JSFunction__JSObject", 0x0 },
+	{ "v8dbg_parent_JSFunctionResultCache__FixedArray", 0x0 },
+	{ "v8dbg_parent_JSGlobalObject__GlobalObject", 0x0 },
+	{ "v8dbg_parent_JSGlobalPropertyCell__HeapObject", 0x0 },
+	{ "v8dbg_parent_JSGlobalProxy__JSObject", 0x0 },
+	{ "v8dbg_parent_JSMessageObject__JSObject", 0x0 },
+	{ "v8dbg_parent_JSObject__HeapObject", 0x0 },
+	{ "v8dbg_parent_JSRegExp__JSObject", 0x0 },
+	{ "v8dbg_parent_JSRegExpResult__JSArray", 0x0 },
+	{ "v8dbg_parent_JSValue__JSObject", 0x0 },
+	{ "v8dbg_parent_Map__HeapObject", 0x0 },
+	{ "v8dbg_parent_NormalizedMapCache__FixedArray", 0x0 },
+	{ "v8dbg_parent_Object__MaybeObject", 0x0 },
+	{ "v8dbg_parent_ObjectTemplateInfo__TemplateInfo", 0x0 },
+	{ "v8dbg_parent_Oddball__HeapObject", 0x0 },
+	{ "v8dbg_parent_Script__Struct", 0x0 },
+	{ "v8dbg_parent_SeqAsciiString__SeqString", 0x0 },
+	{ "v8dbg_parent_SeqString__String", 0x0 },
+	{ "v8dbg_parent_SeqTwoByteString__SeqString", 0x0 },
+	{ "v8dbg_parent_SharedFunctionInfo__HeapObject", 0x0 },
+	{ "v8dbg_parent_SignatureInfo__Struct", 0x0 },
+	{ "v8dbg_parent_Smi__Object", 0x0 },
+	{ "v8dbg_parent_String__HeapObject", 0x0 },
+	{ "v8dbg_parent_Struct__HeapObject", 0x0 },
+	{ "v8dbg_parent_TemplateInfo__Struct", 0x0 },
+	{ "v8dbg_parent_TypeSwitchInfo__Struct", 0x0 },
+
+	{ "v8dbg_frametype_ArgumentsAdaptorFrame", 0x8 },
+	{ "v8dbg_frametype_ConstructFrame", 0x7 },
+	{ "v8dbg_frametype_EntryConstructFrame", 0x2 },
+	{ "v8dbg_frametype_EntryFrame", 0x1 },
+	{ "v8dbg_frametype_ExitFrame", 0x3 },
+	{ "v8dbg_frametype_InternalFrame", 0x6 },
+	{ "v8dbg_frametype_JavaScriptFrame", 0x4 },
+	{ "v8dbg_frametype_OptimizedFrame", 0x5 },
+
+	{ "v8dbg_off_fp_context", -0x4 },
+	{ "v8dbg_off_fp_function", -0x8 },
+	{ "v8dbg_off_fp_marker", -0x8 },
+	{ "v8dbg_off_fp_args", 0x8 },
+
+	{ "v8dbg_prop_idx_content", 0x0 },
+	{ "v8dbg_prop_idx_first", 0x2 },
+	{ "v8dbg_prop_type_field", 0x1 },
+	{ "v8dbg_prop_type_first_phantom", 0x6 },
+	{ "v8dbg_prop_type_mask", 0xf },
+
+	{ "v8dbg_AsciiStringTag", 0x4 },
+	{ "v8dbg_ConsStringTag", 0x1 },
+	{ "v8dbg_ExternalStringTag", 0x2 },
+	{ "v8dbg_FailureTag", 0x3 },
+	{ "v8dbg_FailureTagMask", 0x3 },
+	{ "v8dbg_FirstNonstringType", 0x80 },
+	{ "v8dbg_HeapObjectTag", 0x1 },
+	{ "v8dbg_HeapObjectTagMask", 0x3 },
+	{ "v8dbg_IsNotStringMask", 0x80 },
+	{ "v8dbg_NotStringTag", 0x80 },
+	{ "v8dbg_SeqStringTag", 0x0 },
+	{ "v8dbg_SmiTag", 0x0 },
+	{ "v8dbg_SmiTagMask", 0x1 },
+	{ "v8dbg_SmiValueShift", 0x1 },
+	{ "v8dbg_StringEncodingMask", 0x4 },
+	{ "v8dbg_StringRepresentationMask", 0x3 },
+	{ "v8dbg_StringTag", 0x0 },
+	{ "v8dbg_TwoByteStringTag", 0x0 },
+	{ "v8dbg_PointerSizeLog2", 0x2 },
+
+	{ NULL }
+};
+
+/*
+ * Canned configuration for the V8 bundled with Node.js v0.6.5.
+ */
+static v8_cfg_symbol_t v8_cfg_node_065[] = {
+	{ "v8dbg_type_AccessCheckInfo__ACCESS_CHECK_INFO_TYPE", 0x93 },
+	{ "v8dbg_type_AccessorInfo__ACCESSOR_INFO_TYPE", 0x92 },
+	{ "v8dbg_type_BreakPointInfo__BREAK_POINT_INFO_TYPE", 0x9e },
+	{ "v8dbg_type_ByteArray__BYTE_ARRAY_TYPE", 0x86 },
+	{ "v8dbg_type_CallHandlerInfo__CALL_HANDLER_INFO_TYPE", 0x95 },
+	{ "v8dbg_type_Code__CODE_TYPE", 0x81 },
+	{ "v8dbg_type_CodeCache__CODE_CACHE_TYPE", 0x9b },
+	{ "v8dbg_type_ConsString__CONS_ASCII_STRING_TYPE", 0x5 },
+	{ "v8dbg_type_ConsString__CONS_ASCII_SYMBOL_TYPE", 0x45 },
+	{ "v8dbg_type_ConsString__CONS_STRING_TYPE", 0x1 },
+	{ "v8dbg_type_ConsString__CONS_SYMBOL_TYPE", 0x41 },
+	{ "v8dbg_type_DebugInfo__DEBUG_INFO_TYPE", 0x9d },
+	{ "v8dbg_type_ExternalAsciiString__EXTERNAL_ASCII_STRING_TYPE", 0x6 },
+	{ "v8dbg_type_ExternalAsciiString__EXTERNAL_ASCII_SYMBOL_TYPE", 0x46 },
+	{ "v8dbg_type_ExternalByteArray__EXTERNAL_BYTE_ARRAY_TYPE", 0x87 },
+	{ "v8dbg_type_ExternalDoubleArray__EXTERNAL_DOUBLE_ARRAY_TYPE", 0x8e },
+	{ "v8dbg_type_ExternalFloatArray__EXTERNAL_FLOAT_ARRAY_TYPE", 0x8d },
+	{ "v8dbg_type_ExternalIntArray__EXTERNAL_INT_ARRAY_TYPE", 0x8b },
+	{ "v8dbg_type_ExternalPixelArray__EXTERNAL_PIXEL_ARRAY_TYPE", 0x8f },
+	{ "v8dbg_type_ExternalShortArray__EXTERNAL_SHORT_ARRAY_TYPE", 0x89 },
+	{ "v8dbg_type_ExternalTwoByteString__EXTERNAL_STRING_TYPE", 0x2 },
+	{ "v8dbg_type_ExternalTwoByteString__EXTERNAL_SYMBOL_TYPE", 0x42 },
+	{ "v8dbg_type_ExternalUnsignedByteArray__"
+		"EXTERNAL_UNSIGNED_BYTE_ARRAY_TYPE", 0x88 },
+	{ "v8dbg_type_ExternalUnsignedIntArray__"
+		"EXTERNAL_UNSIGNED_INT_ARRAY_TYPE", 0x8c },
+	{ "v8dbg_type_ExternalUnsignedShortArray__"
+		"EXTERNAL_UNSIGNED_SHORT_ARRAY_TYPE", 0x8a },
+	{ "v8dbg_type_FixedArray__FIXED_ARRAY_TYPE", 0x9f },
+	{ "v8dbg_type_FixedDoubleArray__FIXED_DOUBLE_ARRAY_TYPE", 0x90 },
+	{ "v8dbg_type_Foreign__FOREIGN_TYPE", 0x85 },
+	{ "v8dbg_type_FunctionTemplateInfo__FUNCTION_TEMPLATE_INFO_TYPE",
+		0x96 },
+	{ "v8dbg_type_HeapNumber__HEAP_NUMBER_TYPE", 0x84 },
+	{ "v8dbg_type_InterceptorInfo__INTERCEPTOR_INFO_TYPE", 0x94 },
+	{ "v8dbg_type_JSArray__JS_ARRAY_TYPE", 0xa8 },
+	{ "v8dbg_type_JSBuiltinsObject__JS_BUILTINS_OBJECT_TYPE", 0xa6 },
+	{ "v8dbg_type_JSFunction__JS_FUNCTION_TYPE", 0xac },
+	{ "v8dbg_type_JSFunctionProxy__JS_FUNCTION_PROXY_TYPE", 0xad },
+	{ "v8dbg_type_JSGlobalObject__JS_GLOBAL_OBJECT_TYPE", 0xa5 },
+	{ "v8dbg_type_JSGlobalPropertyCell__JS_GLOBAL_PROPERTY_CELL_TYPE",
+		0x83 },
+	{ "v8dbg_type_JSMessageObject__JS_MESSAGE_OBJECT_TYPE", 0xa1 },
+	{ "v8dbg_type_JSObject__JS_OBJECT_TYPE", 0xa3 },
+	{ "v8dbg_type_JSProxy__JS_PROXY_TYPE", 0xa9 },
+	{ "v8dbg_type_JSRegExp__JS_REGEXP_TYPE", 0xab },
+	{ "v8dbg_type_JSValue__JS_VALUE_TYPE", 0xa2 },
+	{ "v8dbg_type_JSWeakMap__JS_WEAK_MAP_TYPE", 0xaa },
+	{ "v8dbg_type_Map__MAP_TYPE", 0x80 },
+	{ "v8dbg_type_ObjectTemplateInfo__OBJECT_TEMPLATE_INFO_TYPE", 0x97 },
+	{ "v8dbg_type_Oddball__ODDBALL_TYPE", 0x82 },
+	{ "v8dbg_type_PolymorphicCodeCache__POLYMORPHIC_CODE_CACHE_TYPE",
+		0x9c },
+	{ "v8dbg_type_Script__SCRIPT_TYPE", 0x9a },
+	{ "v8dbg_type_SeqAsciiString__ASCII_STRING_TYPE", 0x4 },
+	{ "v8dbg_type_SeqAsciiString__ASCII_SYMBOL_TYPE", 0x44 },
+	{ "v8dbg_type_SeqTwoByteString__STRING_TYPE", 0x0 },
+	{ "v8dbg_type_SeqTwoByteString__SYMBOL_TYPE", 0x40 },
+	{ "v8dbg_type_SharedFunctionInfo__SHARED_FUNCTION_INFO_TYPE", 0xa0 },
+	{ "v8dbg_type_SignatureInfo__SIGNATURE_INFO_TYPE", 0x98 },
+	{ "v8dbg_type_SlicedString__SLICED_ASCII_STRING_TYPE", 0x7 },
+	{ "v8dbg_type_SlicedString__SLICED_STRING_TYPE", 0x3 },
+	{ "v8dbg_type_TypeSwitchInfo__TYPE_SWITCH_INFO_TYPE", 0x99 },
+
+	{ "v8dbg_class_AccessCheckInfo__data__Object", 0xc },
+	{ "v8dbg_class_AccessCheckInfo__indexed_callback__Object", 0x8 },
+	{ "v8dbg_class_AccessCheckInfo__named_callback__Object", 0x4 },
+	{ "v8dbg_class_AccessorInfo__data__Object", 0xc },
+	{ "v8dbg_class_AccessorInfo__flag__Smi", 0x14 },
+	{ "v8dbg_class_AccessorInfo__getter__Object", 0x4 },
+	{ "v8dbg_class_AccessorInfo__name__Object", 0x10 },
+	{ "v8dbg_class_AccessorInfo__setter__Object", 0x8 },
+	{ "v8dbg_class_BreakPointInfo__break_point_objects__Object", 0x10 },
+	{ "v8dbg_class_BreakPointInfo__code_position__Smi", 0x4 },
+	{ "v8dbg_class_BreakPointInfo__source_position__Smi", 0x8 },
+	{ "v8dbg_class_BreakPointInfo__statement_position__Smi", 0xc },
+	{ "v8dbg_class_CallHandlerInfo__callback__Object", 0x4 },
+	{ "v8dbg_class_CallHandlerInfo__data__Object", 0x8 },
+	{ "v8dbg_class_Code__deoptimization_data__FixedArray", 0xc },
+	{ "v8dbg_class_Code__next_code_flushing_candidate__Object", 0x10 },
+	{ "v8dbg_class_Code__relocation_info__ByteArray", 0x8 },
+	{ "v8dbg_class_CodeCache__default_cache__FixedArray", 0x4 },
+	{ "v8dbg_class_CodeCache__normal_type_cache__Object", 0x8 },
+	{ "v8dbg_class_ConsString__first__String", 0xc },
+	{ "v8dbg_class_ConsString__second__String", 0x10 },
+	{ "v8dbg_class_DebugInfo__break_points__FixedArray", 0x14 },
+	{ "v8dbg_class_DebugInfo__code__Code", 0xc },
+	{ "v8dbg_class_DebugInfo__original_code__Code", 0x8 },
+	{ "v8dbg_class_DebugInfo__shared__SharedFunctionInfo", 0x4 },
+	{ "v8dbg_class_ExternalString__resource__Object", 0xc },
+	{ "v8dbg_class_FixedArray__data__uintptr_t", 0x8 },
+	{ "v8dbg_class_FixedArrayBase__length__SMI", 0x4 },
+	{ "v8dbg_class_FunctionTemplateInfo__access_check_info__Object", 0x38 },
+	{ "v8dbg_class_FunctionTemplateInfo__call_code__Object", 0x10 },
+	{ "v8dbg_class_FunctionTemplateInfo__class_name__Object", 0x2c },
+	{ "v8dbg_class_FunctionTemplateInfo__flag__Smi", 0x3c },
+	{ "v8dbg_class_FunctionTemplateInfo__indexed_property_handler__Object",
+		0x24 },
+	{ "v8dbg_class_FunctionTemplateInfo__instance_call_handler__Object",
+		0x34 },
+	{ "v8dbg_class_FunctionTemplateInfo__instance_template__Object", 0x28 },
+	{ "v8dbg_class_FunctionTemplateInfo__named_property_handler__Object",
+		0x20 },
+	{ "v8dbg_class_FunctionTemplateInfo__parent_template__Object", 0x1c },
+	{ "v8dbg_class_FunctionTemplateInfo__property_accessors__Object",
+		0x14 },
+	{ "v8dbg_class_FunctionTemplateInfo__prototype_template__Object",
+		0x18 },
+	{ "v8dbg_class_FunctionTemplateInfo__serial_number__Object", 0xc },
+	{ "v8dbg_class_FunctionTemplateInfo__signature__Object", 0x30 },
+	{ "v8dbg_class_GlobalObject__builtins__JSBuiltinsObject", 0xc },
+	{ "v8dbg_class_GlobalObject__global_context__Context", 0x10 },
+	{ "v8dbg_class_GlobalObject__global_receiver__JSObject", 0x14 },
+	{ "v8dbg_class_HeapNumber__value__double", 0x4 },
+	{ "v8dbg_class_HeapObject__map__Map", 0x0 },
+	{ "v8dbg_class_InterceptorInfo__data__Object", 0x18 },
+	{ "v8dbg_class_InterceptorInfo__deleter__Object", 0x10 },
+	{ "v8dbg_class_InterceptorInfo__enumerator__Object", 0x14 },
+	{ "v8dbg_class_InterceptorInfo__getter__Object", 0x4 },
+	{ "v8dbg_class_InterceptorInfo__query__Object", 0xc },
+	{ "v8dbg_class_InterceptorInfo__setter__Object", 0x8 },
+	{ "v8dbg_class_JSArray__length__Object", 0xc },
+	{ "v8dbg_class_JSFunction__literals__FixedArray", 0x1c },
+	{ "v8dbg_class_JSFunction__next_function_link__Object", 0x20 },
+	{ "v8dbg_class_JSFunction__prototype_or_initial_map__Object", 0x10 },
+	{ "v8dbg_class_JSFunction__shared__SharedFunctionInfo", 0x14 },
+	{ "v8dbg_class_JSFunctionProxy__call_trap__Object", 0x8 },
+	{ "v8dbg_class_JSFunctionProxy__construct_trap__Object", 0xc },
+	{ "v8dbg_class_JSGlobalProxy__context__Object", 0xc },
+	{ "v8dbg_class_JSMessageObject__arguments__JSArray", 0x10 },
+	{ "v8dbg_class_JSMessageObject__end_position__SMI", 0x24 },
+	{ "v8dbg_class_JSMessageObject__script__Object", 0x14 },
+	{ "v8dbg_class_JSMessageObject__stack_frames__Object", 0x1c },
+	{ "v8dbg_class_JSMessageObject__stack_trace__Object", 0x18 },
+	{ "v8dbg_class_JSMessageObject__start_position__SMI", 0x20 },
+	{ "v8dbg_class_JSMessageObject__type__String", 0xc },
+	{ "v8dbg_class_JSObject__elements__Object", 0x8 },
+	{ "v8dbg_class_JSObject__properties__FixedArray", 0x4 },
+	{ "v8dbg_class_JSProxy__handler__Object", 0x4 },
+	{ "v8dbg_class_JSRegExp__data__Object", 0xc },
+	{ "v8dbg_class_JSValue__value__Object", 0xc },
+	{ "v8dbg_class_JSWeakMap__next__Object", 0x10 },
+	{ "v8dbg_class_JSWeakMap__table__ObjectHashTable", 0xc },
+	{ "v8dbg_class_Map__code_cache__Object", 0x18 },
+	{ "v8dbg_class_Map__constructor__Object", 0x10 },
+	{ "v8dbg_class_Map__inobject_properties__int", 0x5 },
+	{ "v8dbg_class_Map__instance_attributes__int", 0x8 },
+	{ "v8dbg_class_Map__instance_descriptors__int", 0x14 },
+	{ "v8dbg_class_Map__instance_size__int", 0x4 },
+	{ "v8dbg_class_Map__prototype_transitions__FixedArray", 0x1c },
+	{ "v8dbg_class_ObjectTemplateInfo__constructor__Object", 0xc },
+	{ "v8dbg_class_ObjectTemplateInfo__internal_field_count__Object",
+		0x10 },
+	{ "v8dbg_class_Oddball__to_number__Object", 0x8 },
+	{ "v8dbg_class_Oddball__to_string__String", 0x4 },
+	{ "v8dbg_class_PolymorphicCodeCache__cache__Object", 0x4 },
+	{ "v8dbg_class_Script__column_offset__Smi", 0x10 },
+	{ "v8dbg_class_Script__compilation_type__Smi", 0x24 },
+	{ "v8dbg_class_Script__context_data__Object", 0x18 },
+	{ "v8dbg_class_Script__data__Object", 0x14 },
+	{ "v8dbg_class_Script__eval_from_instructions_offset__Smi", 0x34 },
+	{ "v8dbg_class_Script__eval_from_shared__Object", 0x30 },
+	{ "v8dbg_class_Script__id__Object", 0x2c },
+	{ "v8dbg_class_Script__line_ends__Object", 0x28 },
+	{ "v8dbg_class_Script__line_offset__Smi", 0xc },
+	{ "v8dbg_class_Script__name__Object", 0x8 },
+	{ "v8dbg_class_Script__source__Object", 0x4 },
+	{ "v8dbg_class_Script__type__Smi", 0x20 },
+	{ "v8dbg_class_Script__wrapper__Foreign", 0x1c },
+	{ "v8dbg_class_SeqAsciiString__chars__char", 0xc },
+	{ "v8dbg_class_SharedFunctionInfo__compiler_hints__SMI", 0x50 },
+	{ "v8dbg_class_SharedFunctionInfo__construct_stub__Code", 0x10 },
+	{ "v8dbg_class_SharedFunctionInfo__debug_info__Object", 0x20 },
+	{ "v8dbg_class_SharedFunctionInfo__end_position__SMI", 0x48 },
+	{ "v8dbg_class_SharedFunctionInfo__expected_nof_properties__SMI",
+		0x3c },
+	{ "v8dbg_class_SharedFunctionInfo__formal_parameter_count__SMI", 0x38 },
+	{ "v8dbg_class_SharedFunctionInfo__function_data__Object", 0x18 },
+	{ "v8dbg_class_SharedFunctionInfo__function_token_position__SMI",
+		0x4c },
+	{ "v8dbg_class_SharedFunctionInfo__inferred_name__String", 0x24 },
+	{ "v8dbg_class_SharedFunctionInfo__initial_map__Object", 0x28 },
+	{ "v8dbg_class_SharedFunctionInfo__instance_class_name__Object", 0x14 },
+	{ "v8dbg_class_SharedFunctionInfo__length__SMI", 0x34 },
+	{ "v8dbg_class_SharedFunctionInfo__name__Object", 0x4 },
+	{ "v8dbg_class_SharedFunctionInfo__num_literals__SMI", 0x40 },
+	{ "v8dbg_class_SharedFunctionInfo__opt_count__SMI", 0x58 },
+	{ "v8dbg_class_SharedFunctionInfo__script__Object", 0x1c },
+	{ "v8dbg_class_SharedFunctionInfo__"
+		"start_position_and_type__SMI", 0x44 },
+	{ "v8dbg_class_SharedFunctionInfo__"
+		"this_property_assignments__Object", 0x2c },
+	{ "v8dbg_class_SharedFunctionInfo__"
+		"this_property_assignments_count__SMI", 0x54 },
+	{ "v8dbg_class_SignatureInfo__args__Object", 0x8 },
+	{ "v8dbg_class_SignatureInfo__receiver__Object", 0x4 },
+	{ "v8dbg_class_SlicedString__offset__SMI", 0x10 },
+	{ "v8dbg_class_String__length__SMI", 0x4 },
+	{ "v8dbg_class_TemplateInfo__property_list__Object", 0x8 },
+	{ "v8dbg_class_TemplateInfo__tag__Object", 0x4 },
+	{ "v8dbg_class_TypeSwitchInfo__types__Object", 0x4 },
+
+	{ "v8dbg_parent_AccessCheckInfo__Struct", 0x0 },
+	{ "v8dbg_parent_AccessorInfo__Struct", 0x0 },
+	{ "v8dbg_parent_BreakPointInfo__Struct", 0x0 },
+	{ "v8dbg_parent_ByteArray__FixedArrayBase", 0x0 },
+	{ "v8dbg_parent_CallHandlerInfo__Struct", 0x0 },
+	{ "v8dbg_parent_Code__HeapObject", 0x0 },
+	{ "v8dbg_parent_CodeCache__Struct", 0x0 },
+	{ "v8dbg_parent_ConsString__String", 0x0 },
+	{ "v8dbg_parent_DebugInfo__Struct", 0x0 },
+	{ "v8dbg_parent_DeoptimizationInputData__FixedArray", 0x0 },
+	{ "v8dbg_parent_DeoptimizationOutputData__FixedArray", 0x0 },
+	{ "v8dbg_parent_DescriptorArray__FixedArray", 0x0 },
+	{ "v8dbg_parent_ExternalArray__FixedArrayBase", 0x0 },
+	{ "v8dbg_parent_ExternalAsciiString__ExternalString", 0x0 },
+	{ "v8dbg_parent_ExternalByteArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_ExternalDoubleArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_ExternalFloatArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_ExternalIntArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_ExternalPixelArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_ExternalShortArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_ExternalString__String", 0x0 },
+	{ "v8dbg_parent_ExternalTwoByteString__ExternalString", 0x0 },
+	{ "v8dbg_parent_ExternalUnsignedByteArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_ExternalUnsignedIntArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_ExternalUnsignedShortArray__ExternalArray", 0x0 },
+	{ "v8dbg_parent_Failure__MaybeObject", 0x0 },
+	{ "v8dbg_parent_FixedArray__FixedArrayBase", 0x0 },
+	{ "v8dbg_parent_FixedArrayBase__HeapObject", 0x0 },
+	{ "v8dbg_parent_FixedDoubleArray__FixedArrayBase", 0x0 },
+	{ "v8dbg_parent_Foreign__HeapObject", 0x0 },
+	{ "v8dbg_parent_FunctionTemplateInfo__TemplateInfo", 0x0 },
+	{ "v8dbg_parent_GlobalObject__JSObject", 0x0 },
+	{ "v8dbg_parent_HashTable__FixedArray", 0x0 },
+	{ "v8dbg_parent_HeapNumber__HeapObject", 0x0 },
+	{ "v8dbg_parent_HeapObject__Object", 0x0 },
+	{ "v8dbg_parent_InterceptorInfo__Struct", 0x0 },
+	{ "v8dbg_parent_JSArray__JSObject", 0x0 },
+	{ "v8dbg_parent_JSBuiltinsObject__GlobalObject", 0x0 },
+	{ "v8dbg_parent_JSFunction__JSObject", 0x0 },
+	{ "v8dbg_parent_JSFunctionProxy__JSProxy", 0x0 },
+	{ "v8dbg_parent_JSFunctionResultCache__FixedArray", 0x0 },
+	{ "v8dbg_parent_JSGlobalObject__GlobalObject", 0x0 },
+	{ "v8dbg_parent_JSGlobalPropertyCell__HeapObject", 0x0 },
+	{ "v8dbg_parent_JSMessageObject__JSObject", 0x0 },
+	{ "v8dbg_parent_JSObject__JSReceiver", 0x0 },
+	{ "v8dbg_parent_JSProxy__JSReceiver", 0x0 },
+	{ "v8dbg_parent_JSReceiver__HeapObject", 0x0 },
+	{ "v8dbg_parent_JSRegExp__JSObject", 0x0 },
+	{ "v8dbg_parent_JSRegExpResult__JSArray", 0x0 },
+	{ "v8dbg_parent_JSValue__JSObject", 0x0 },
+	{ "v8dbg_parent_JSWeakMap__JSObject", 0x0 },
+	{ "v8dbg_parent_Map__HeapObject", 0x0 },
+	{ "v8dbg_parent_NormalizedMapCache__FixedArray", 0x0 },
+	{ "v8dbg_parent_ObjectTemplateInfo__TemplateInfo", 0x0 },
+	{ "v8dbg_parent_Oddball__HeapObject", 0x0 },
+	{ "v8dbg_parent_PolymorphicCodeCache__Struct", 0x0 },
+	{ "v8dbg_parent_Script__Struct", 0x0 },
+	{ "v8dbg_parent_SeqAsciiString__SeqString", 0x0 },
+	{ "v8dbg_parent_SeqString__String", 0x0 },
+	{ "v8dbg_parent_SeqTwoByteString__SeqString", 0x0 },
+	{ "v8dbg_parent_SharedFunctionInfo__HeapObject", 0x0 },
+	{ "v8dbg_parent_SignatureInfo__Struct", 0x0 },
+	{ "v8dbg_parent_SlicedString__String", 0x0 },
+	{ "v8dbg_parent_Smi__Object", 0x0 },
+	{ "v8dbg_parent_String__HeapObject", 0x0 },
+	{ "v8dbg_parent_Struct__HeapObject", 0x0 },
+	{ "v8dbg_parent_TemplateInfo__Struct", 0x0 },
+	{ "v8dbg_parent_TypeSwitchInfo__Struct", 0x0 },
+
+	{ "v8dbg_frametype_ArgumentsAdaptorFrame", 0x8 },
+	{ "v8dbg_frametype_ConstructFrame", 0x7 },
+	{ "v8dbg_frametype_EntryConstructFrame", 0x2 },
+	{ "v8dbg_frametype_EntryFrame", 0x1 },
+	{ "v8dbg_frametype_ExitFrame", 0x3 },
+	{ "v8dbg_frametype_InternalFrame", 0x6 },
+	{ "v8dbg_frametype_JavaScriptFrame", 0x4 },
+	{ "v8dbg_frametype_OptimizedFrame", 0x5 },
+
+	{ "v8dbg_off_fp_args", 0x8 },
+	{ "v8dbg_off_fp_context", -0x4 },
+	{ "v8dbg_off_fp_function", -0x8 },
+	{ "v8dbg_off_fp_marker", -0x8 },
+
+	{ "v8dbg_prop_idx_content", 0x1 },
+	{ "v8dbg_prop_idx_first", 0x3 },
+	{ "v8dbg_prop_type_field", 0x1 },
+	{ "v8dbg_prop_type_first_phantom", 0x6 },
+	{ "v8dbg_prop_type_mask", 0xf },
+
+	{ "v8dbg_AsciiStringTag", 0x4 },
+	{ "v8dbg_PointerSizeLog2", 0x2 },
+	{ "v8dbg_SeqStringTag", 0x0 },
+	{ "v8dbg_SmiTag", 0x0 },
+	{ "v8dbg_SmiTagMask", 0x1 },
+	{ "v8dbg_SmiValueShift", 0x1 },
+	{ "v8dbg_StringEncodingMask", 0x4 },
+	{ "v8dbg_StringRepresentationMask", 0x3 },
+	{ "v8dbg_StringTag", 0x0 },
+	{ "v8dbg_TwoByteStringTag", 0x0 },
+	{ "v8dbg_ConsStringTag", 0x1 },
+	{ "v8dbg_ExternalStringTag", 0x2 },
+	{ "v8dbg_FailureTag", 0x3 },
+	{ "v8dbg_FailureTagMask", 0x3 },
+	{ "v8dbg_FirstNonstringType", 0x80 },
+	{ "v8dbg_HeapObjectTag", 0x1 },
+	{ "v8dbg_HeapObjectTagMask", 0x3 },
+	{ "v8dbg_IsNotStringMask", 0x80 },
+	{ "v8dbg_NotStringTag", 0x80 },
+
+	{ NULL },
+};
+
+v8_cfg_t v8_cfgs[] = {
+	{ "node-0.4", "node 0.4 versions starting with 0.4.8", v8_cfg_node_04,
+	    v8cfg_canned_iter, v8cfg_canned_readsym },
+	{ "node-0.6.5", "node v0.6.5", v8_cfg_node_065,
+	    v8cfg_canned_iter, v8cfg_canned_readsym },
+	{ NULL }
+};
+
+v8_cfg_t v8_cfg_target = { NULL, NULL, NULL, v8cfg_target_iter,
+	v8cfg_target_readsym };
diff --git a/usr/src/cmd/mdb/common/modules/v8/v8dbg.h b/usr/src/cmd/mdb/common/modules/v8/v8dbg.h
new file mode 100644
index 0000000000..486ac5e255
--- /dev/null
+++ b/usr/src/cmd/mdb/common/modules/v8/v8dbg.h
@@ -0,0 +1,81 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2011, Joyent, Inc. All rights reserved.
+ */
+
+/*
+ * v8dbg.h: macros for use by V8 heap inspection tools.  The consumer must
+ * define values for various tags and shifts.  The MDB module gets these
+ * constants from information encoded in the binary itself.
+ */
+
+#ifndef _V8DBG_H
+#define	_V8DBG_H
+
+/*
+ * Recall that while V8 heap objects are always 4-byte aligned, heap object
+ * pointers always have the last bit set.  So when looking for a field nominally
+ * at offset X, one must be sure to clear the tag bit first.
+ */
+#define	V8_OFF_HEAP(x)			((x) - V8_HeapObjectTag)
+
+/*
+ * Determine whether a given pointer refers to a SMI, Failure, or HeapObject.
+ */
+#define	V8_IS_SMI(ptr)		(((ptr) & V8_SmiTagMask) == V8_SmiTag)
+#define	V8_IS_FAILURE(ptr)	(((ptr) & V8_FailureTagMask) == V8_FailureTag)
+#define	V8_IS_HEAPOBJECT(ptr)	\
+	(((ptr) & V8_HeapObjectTagMask) == V8_HeapObjectTag)
+
+/*
+ * Extract the value of a SMI "pointer".  Recall that small integers are stored
+ * using the upper 31 bits.
+ */
+#define	V8_SMI_VALUE(smi)	((smi) >> V8_SmiValueShift)
+
+/*
+ * Determine the encoding and representation of a V8 string.
+ */
+#define	V8_TYPE_STRING(type)	(((type) & V8_IsNotStringMask) == V8_StringTag)
+
+#define	V8_STRENC_ASCII(type)	\
+	(((type) & V8_StringEncodingMask) == V8_AsciiStringTag)
+
+#define	V8_STRREP_SEQ(type)	\
+	(((type) & V8_StringRepresentationMask) == V8_SeqStringTag)
+#define	V8_STRREP_CONS(type)	\
+	(((type) & V8_StringRepresentationMask) == V8_ConsStringTag)
+#define	V8_STRREP_EXT(type)	\
+	(((type) & V8_StringRepresentationMask) == V8_ExternalStringTag)
+
+/*
+ * Several of the following constants and transformations are hardcoded in V8 as
+ * well, so there's no way to extract them programmatically from the binary.
+ */
+#define	V8_DESC_KEYIDX(x)		((x) + V8_PROP_IDX_FIRST)
+#define	V8_DESC_VALIDX(x)		((x) << 1)
+#define	V8_DESC_DETIDX(x)		(((x) << 1) + 1)
+
+#define	V8_DESC_ISFIELD(x)		\
+	(V8_SMI_VALUE((x) & V8_PROP_TYPE_MASK) == V8_PROP_TYPE_FIELD)
+
+#endif /* _V8DBG_H */
diff --git a/usr/src/cmd/mdb/intel/ia32/v8/Makefile b/usr/src/cmd/mdb/intel/ia32/v8/Makefile
new file mode 100644
index 0000000000..a824d4a8e3
--- /dev/null
+++ b/usr/src/cmd/mdb/intel/ia32/v8/Makefile
@@ -0,0 +1,42 @@
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License, Version 1.0 only
+# (the "License").  You may not use this file except in compliance
+# with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+#
+# Copyright (c) 2011, Joyent, Inc. All rights reserved.
+#
+
+MODULE = v8.so
+MDBTGT = proc
+
+MODSRCS_DIR = ../../../common/modules/v8
+
+MODSRCS = mdb_v8.c mdb_v8_cfg.c
+
+include ../../../../Makefile.cmd
+include ../../Makefile.ia32
+include ../../../Makefile.module
+
+%.o: $(MODSRCS_DIR)/%.c
+	$(COMPILE.c) $<
+	$(CTFCONVERT_O)
+
+%.ln: $(MODSRCS_DIR)/%.c
+	$(LINT.c) -c $<