6885 CTF Everywhere Part 1

6886 Want ctfdiff
6887 ctfdump should be written in terms of libctf
6888 ctfmerge should be implemented in terms of libctf
6889 ctfconvert should be implemented in terms of libctf
6890 Want general workq
6891 Want general mergeq
6892 ctf_add_encoded assigns() incorrect byte size to types
6893 ctf_add_{struct,union,enum} can reuse forwards
6894 ctf_add_{struct,union,enum} occasionally forget to dirty the ctf_file_t
6895 ctf_add_member could better handle bitfields
6896 ctf_type_size() reports wrong size for forwards
6897 Want libctf ctf_kind_name() function
6898 Want libctf function to set struct/union size
Portions contributed by: John Levon <john.levon@joyent.com>
Portions contributed by: Richard Lowe <richlowe@richlowe.net>
Reviewed by: John Levon <john.levon@joyent.com>
Reviewed by: Andy Fiddaman <andy@omniosce.org>
Reviewed by: Gergő Doma <domag02@gmail.com>
Approved by: Dan McDonald <danmcd@joyent.com>

1 files changed, 1551 insertions, 0 deletions

diff --git a/usr/src/lib/libctf/common/ctf_merge.c b/usr/src/lib/libctf/common/ctf_merge.c
new file mode 100644
index 0000000000..c93a2a4f7c
--- /dev/null
+++ b/usr/src/lib/libctf/common/ctf_merge.c
@@ -0,0 +1,1551 @@
+/*
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ */
+
+/*
+ * Copyright (c) 2015 Joyent, Inc.
+ */
+
+/*
+ * To perform a merge of two CTF containers, we first diff the two containers
+ * types. For every type that's in the src container, but not in the dst
+ * container, we note it and add it to dst container. If there are any objects
+ * or functions associated with src, we go through and update the types that
+ * they refer to such that they all refer to types in the dst container.
+ *
+ * The bulk of the logic for the merge, after we've run the diff, occurs in
+ * ctf_merge_common().
+ *
+ * In terms of exported APIs, we don't really export a simple merge two
+ * containers, as the general way this is used, in something like ctfmerge(1),
+ * is to add all the containers and then let us figure out the best way to merge
+ * it.
+ */
+
+#include <libctf_impl.h>
+#include <sys/debug.h>
+#include <sys/list.h>
+#include <stddef.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <mergeq.h>
+#include <errno.h>
+
+typedef struct ctf_merge_tinfo {
+	uint16_t cmt_map;	/* Map to the type in out */
+	boolean_t cmt_fixup;
+	boolean_t cmt_forward;
+	boolean_t cmt_missing;
+} ctf_merge_tinfo_t;
+
+/*
+ * State required for doing an individual merge of two containers.
+ */
+typedef struct ctf_merge_types {
+	ctf_file_t *cm_out;		/* Output CTF file */
+	ctf_file_t *cm_src;		/* Input CTF file */
+	ctf_merge_tinfo_t *cm_tmap;	/* Type state information */
+	boolean_t cm_dedup;		/* Are we doing a dedup? */
+	boolean_t cm_unique;		/* are we doing a uniquify? */
+} ctf_merge_types_t;
+
+typedef struct ctf_merge_objmap {
+	list_node_t cmo_node;
+	const char *cmo_name;		/* Symbol name */
+	ulong_t cmo_idx;		/* Symbol ID */
+	ctf_id_t cmo_tid;		/* Type ID */
+} ctf_merge_objmap_t;
+
+typedef struct ctf_merge_funcmap {
+	list_node_t cmf_node;
+	const char *cmf_name;		/* Symbol name */
+	ulong_t cmf_idx;		/* Symbol ID */
+	ctf_id_t cmf_rtid;		/* Type ID */
+	uint_t cmf_flags;		/* ctf_funcinfo_t ctc_flags */
+	uint_t cmf_argc;		/* Number of arguments */
+	ctf_id_t cmf_args[];		/* Types of arguments */
+} ctf_merge_funcmap_t;
+
+typedef struct ctf_merge_input {
+	list_node_t cmi_node;
+	ctf_file_t *cmi_input;
+	list_t cmi_omap;
+	list_t cmi_fmap;
+	boolean_t cmi_created;
+} ctf_merge_input_t;
+
+struct ctf_merge_handle {
+	list_t cmh_inputs;		/* Input list */
+	uint_t cmh_ninputs;		/* Number of inputs */
+	uint_t cmh_nthreads;		/* Number of threads to use */
+	ctf_file_t *cmh_unique;		/* ctf to uniquify against */
+	boolean_t cmh_msyms;		/* Should we merge symbols/funcs? */
+	int cmh_ofd;			/* FD for output file */
+	int cmh_flags;			/* Flags that control merge behavior */
+	char *cmh_label;		/* Optional label */
+	char *cmh_pname;		/* Parent name */
+};
+
+static int ctf_merge_add_type(ctf_merge_types_t *, ctf_id_t);
+
+static ctf_id_t
+ctf_merge_gettype(ctf_merge_types_t *cmp, ctf_id_t id)
+{
+	if (cmp->cm_dedup == B_FALSE) {
+		VERIFY(cmp->cm_tmap[id].cmt_map != 0);
+		return (cmp->cm_tmap[id].cmt_map);
+	}
+
+	while (cmp->cm_tmap[id].cmt_missing == B_FALSE) {
+		VERIFY(cmp->cm_tmap[id].cmt_map != 0);
+		id = cmp->cm_tmap[id].cmt_map;
+	}
+	VERIFY(cmp->cm_tmap[id].cmt_map != 0);
+	return (cmp->cm_tmap[id].cmt_map);
+}
+
+static void
+ctf_merge_diffcb(ctf_file_t *ifp, ctf_id_t iid, boolean_t same, ctf_file_t *ofp,
+    ctf_id_t oid, void *arg)
+{
+	ctf_merge_types_t *cmp = arg;
+	ctf_merge_tinfo_t *cmt = cmp->cm_tmap;
+
+	if (same == B_TRUE) {
+		if (ctf_type_kind(ifp, iid) == CTF_K_FORWARD &&
+		    ctf_type_kind(ofp, oid) != CTF_K_FORWARD) {
+			VERIFY(cmt[oid].cmt_map == 0);
+
+			/*
+			 * If we're uniquifying types, it's possible for the
+			 * container that we're uniquifying against to have a
+			 * forward which exists in the container being reduced.
+			 * For example, genunix has the machcpu structure as a
+			 * forward which is actually in unix and we uniquify
+			 * unix against genunix. In such cases, we explicitly do
+			 * not do any mapping of the forward information, lest
+			 * we risk losing the real definition. Instead, mark
+			 * that it's missing.
+			 */
+			if (cmp->cm_unique == B_TRUE) {
+				cmt[oid].cmt_missing = B_TRUE;
+				return;
+			}
+
+			cmt[oid].cmt_map = iid;
+			cmt[oid].cmt_forward = B_TRUE;
+			ctf_dprintf("merge diff forward mapped %d->%d\n", oid,
+			    iid);
+			return;
+		}
+
+		/*
+		 * We could have multiple things that a given type ends up
+		 * matching in the world of forwards and pointers to forwards.
+		 * For now just take the first one...
+		 */
+		if (cmt[oid].cmt_map != 0)
+			return;
+		cmt[oid].cmt_map = iid;
+		ctf_dprintf("merge diff mapped %d->%d\n", oid, iid);
+	} else if (ifp == cmp->cm_src) {
+		VERIFY(cmt[iid].cmt_map == 0);
+		cmt[iid].cmt_missing = B_TRUE;
+		ctf_dprintf("merge diff said %d is missing\n", iid);
+	}
+}
+
+static int
+ctf_merge_add_number(ctf_merge_types_t *cmp, ctf_id_t id)
+{
+	int ret, flags;
+	const ctf_type_t *tp;
+	const char *name;
+	ctf_encoding_t en;
+
+	if (ctf_type_encoding(cmp->cm_src, id, &en) != 0)
+		return (CTF_ERR);
+
+	tp = LCTF_INDEX_TO_TYPEPTR(cmp->cm_src, id);
+	name = ctf_strraw(cmp->cm_src, tp->ctt_name);
+	if (CTF_INFO_ISROOT(tp->ctt_info) != 0)
+		flags = CTF_ADD_ROOT;
+	else
+		flags = CTF_ADD_NONROOT;
+
+	ret = ctf_add_encoded(cmp->cm_out, flags, name, &en,
+	    ctf_type_kind(cmp->cm_src, id));
+
+	if (ret == CTF_ERR)
+		return (ret);
+
+	VERIFY(cmp->cm_tmap[id].cmt_map == 0);
+	cmp->cm_tmap[id].cmt_map = ret;
+	return (0);
+}
+
+static int
+ctf_merge_add_array(ctf_merge_types_t *cmp, ctf_id_t id)
+{
+	int ret, flags;
+	const ctf_type_t *tp;
+	ctf_arinfo_t ar;
+
+	if (ctf_array_info(cmp->cm_src, id, &ar) == CTF_ERR)
+		return (CTF_ERR);
+
+	tp = LCTF_INDEX_TO_TYPEPTR(cmp->cm_src, id);
+	if (CTF_INFO_ISROOT(tp->ctt_info) != 0)
+		flags = CTF_ADD_ROOT;
+	else
+		flags = CTF_ADD_NONROOT;
+
+	if (cmp->cm_tmap[ar.ctr_contents].cmt_map == 0) {
+		ret = ctf_merge_add_type(cmp, ar.ctr_contents);
+		if (ret != 0)
+			return (ret);
+		ASSERT(cmp->cm_tmap[ar.ctr_contents].cmt_map != 0);
+	}
+	ar.ctr_contents = ctf_merge_gettype(cmp, ar.ctr_contents);
+
+	if (cmp->cm_tmap[ar.ctr_index].cmt_map == 0) {
+		ret = ctf_merge_add_type(cmp, ar.ctr_index);
+		if (ret != 0)
+			return (ret);
+		ASSERT(cmp->cm_tmap[ar.ctr_index].cmt_map != 0);
+	}
+	ar.ctr_index = ctf_merge_gettype(cmp, ar.ctr_index);
+
+	ret = ctf_add_array(cmp->cm_out, flags, &ar);
+	if (ret == CTF_ERR)
+		return (ret);
+
+	VERIFY(cmp->cm_tmap[id].cmt_map == 0);
+	cmp->cm_tmap[id].cmt_map = ret;
+
+	return (0);
+}
+
+static int
+ctf_merge_add_reftype(ctf_merge_types_t *cmp, ctf_id_t id)
+{
+	int ret, flags;
+	const ctf_type_t *tp;
+	ctf_id_t reftype;
+	const char *name;
+
+	tp = LCTF_INDEX_TO_TYPEPTR(cmp->cm_src, id);
+	name = ctf_strraw(cmp->cm_src, tp->ctt_name);
+	if (CTF_INFO_ISROOT(tp->ctt_info) != 0)
+		flags = CTF_ADD_ROOT;
+	else
+		flags = CTF_ADD_NONROOT;
+
+	reftype = ctf_type_reference(cmp->cm_src, id);
+	if (reftype == CTF_ERR)
+		return (ctf_set_errno(cmp->cm_out, ctf_errno(cmp->cm_src)));
+
+	if (cmp->cm_tmap[reftype].cmt_map == 0) {
+		ret = ctf_merge_add_type(cmp, reftype);
+		if (ret != 0)
+			return (ret);
+		ASSERT(cmp->cm_tmap[reftype].cmt_map != 0);
+	}
+	reftype = ctf_merge_gettype(cmp, reftype);
+
+	ret = ctf_add_reftype(cmp->cm_out, flags, name, reftype,
+	    ctf_type_kind(cmp->cm_src, id));
+	if (ret == CTF_ERR)
+		return (ret);
+
+	VERIFY(cmp->cm_tmap[id].cmt_map == 0);
+	cmp->cm_tmap[id].cmt_map = ret;
+	return (0);
+}
+
+static int
+ctf_merge_add_typedef(ctf_merge_types_t *cmp, ctf_id_t id)
+{
+	int ret, flags;
+	const ctf_type_t *tp;
+	const char *name;
+	ctf_id_t reftype;
+
+	tp = LCTF_INDEX_TO_TYPEPTR(cmp->cm_src, id);
+	name = ctf_strraw(cmp->cm_src, tp->ctt_name);
+	if (CTF_INFO_ISROOT(tp->ctt_info) != 0)
+		flags = CTF_ADD_ROOT;
+	else
+		flags = CTF_ADD_NONROOT;
+
+	reftype = ctf_type_reference(cmp->cm_src, id);
+	if (reftype == CTF_ERR)
+		return (ctf_set_errno(cmp->cm_out, ctf_errno(cmp->cm_src)));
+
+	if (cmp->cm_tmap[reftype].cmt_map == 0) {
+		ret = ctf_merge_add_type(cmp, reftype);
+		if (ret != 0)
+			return (ret);
+		ASSERT(cmp->cm_tmap[reftype].cmt_map != 0);
+	}
+	reftype = ctf_merge_gettype(cmp, reftype);
+
+	ret = ctf_add_typedef(cmp->cm_out, flags, name, reftype);
+	if (ret == CTF_ERR)
+		return (ret);
+
+	VERIFY(cmp->cm_tmap[id].cmt_map == 0);
+	cmp->cm_tmap[id].cmt_map = ret;
+	return (0);
+}
+
+typedef struct ctf_merge_enum {
+	ctf_file_t *cme_fp;
+	ctf_id_t cme_id;
+} ctf_merge_enum_t;
+
+static int
+ctf_merge_add_enumerator(const char *name, int value, void *arg)
+{
+	ctf_merge_enum_t *cmep = arg;
+
+	return (ctf_add_enumerator(cmep->cme_fp, cmep->cme_id, name, value) ==
+	    CTF_ERR);
+}
+
+static int
+ctf_merge_add_enum(ctf_merge_types_t *cmp, ctf_id_t id)
+{
+	int flags;
+	const ctf_type_t *tp;
+	const char *name;
+	ctf_id_t enumid;
+	ctf_merge_enum_t cme;
+
+	tp = LCTF_INDEX_TO_TYPEPTR(cmp->cm_src, id);
+	name = ctf_strraw(cmp->cm_src, tp->ctt_name);
+	if (CTF_INFO_ISROOT(tp->ctt_info) != 0)
+		flags = CTF_ADD_ROOT;
+	else
+		flags = CTF_ADD_NONROOT;
+
+	enumid = ctf_add_enum(cmp->cm_out, flags, name);
+	if (enumid == CTF_ERR)
+		return (enumid);
+
+	cme.cme_fp = cmp->cm_out;
+	cme.cme_id = enumid;
+	if (ctf_enum_iter(cmp->cm_src, id, ctf_merge_add_enumerator,
+	    &cme) != 0)
+		return (CTF_ERR);
+
+	VERIFY(cmp->cm_tmap[id].cmt_map == 0);
+	cmp->cm_tmap[id].cmt_map = enumid;
+	return (0);
+}
+
+static int
+ctf_merge_add_func(ctf_merge_types_t *cmp, ctf_id_t id)
+{
+	int ret, flags, i;
+	const ctf_type_t *tp;
+	ctf_funcinfo_t ctc;
+	ctf_id_t *argv;
+
+	tp = LCTF_INDEX_TO_TYPEPTR(cmp->cm_src, id);
+	if (CTF_INFO_ISROOT(tp->ctt_info) != 0)
+		flags = CTF_ADD_ROOT;
+	else
+		flags = CTF_ADD_NONROOT;
+
+	if (ctf_func_info_by_id(cmp->cm_src, id, &ctc) == CTF_ERR)
+		return (ctf_set_errno(cmp->cm_out, ctf_errno(cmp->cm_src)));
+
+	argv = ctf_alloc(sizeof (ctf_id_t) * ctc.ctc_argc);
+	if (argv == NULL)
+		return (ctf_set_errno(cmp->cm_out, ENOMEM));
+	if (ctf_func_args_by_id(cmp->cm_src, id, ctc.ctc_argc, argv) ==
+	    CTF_ERR) {
+		ctf_free(argv, sizeof (ctf_id_t) * ctc.ctc_argc);
+		return (ctf_set_errno(cmp->cm_out, ctf_errno(cmp->cm_src)));
+	}
+
+	if (cmp->cm_tmap[ctc.ctc_return].cmt_map == 0) {
+		ret = ctf_merge_add_type(cmp, ctc.ctc_return);
+		if (ret != 0)
+			return (ret);
+		ASSERT(cmp->cm_tmap[ctc.ctc_return].cmt_map != 0);
+	}
+	ctc.ctc_return = ctf_merge_gettype(cmp, ctc.ctc_return);
+
+	for (i = 0; i < ctc.ctc_argc; i++) {
+		if (cmp->cm_tmap[argv[i]].cmt_map == 0) {
+			ret = ctf_merge_add_type(cmp, argv[i]);
+			if (ret != 0)
+				return (ret);
+			ASSERT(cmp->cm_tmap[argv[i]].cmt_map != 0);
+		}
+		argv[i] = ctf_merge_gettype(cmp, argv[i]);
+	}
+
+	ret = ctf_add_funcptr(cmp->cm_out, flags, &ctc, argv);
+	ctf_free(argv, sizeof (ctf_id_t) * ctc.ctc_argc);
+	if (ret == CTF_ERR)
+		return (ret);
+
+	VERIFY(cmp->cm_tmap[id].cmt_map == 0);
+	cmp->cm_tmap[id].cmt_map = ret;
+	return (0);
+}
+
+static int
+ctf_merge_add_forward(ctf_merge_types_t *cmp, ctf_id_t id)
+{
+	int ret, flags;
+	const ctf_type_t *tp;
+	const char *name;
+
+	tp = LCTF_INDEX_TO_TYPEPTR(cmp->cm_src, id);
+	name = ctf_strraw(cmp->cm_src, tp->ctt_name);
+	if (CTF_INFO_ISROOT(tp->ctt_info) != 0)
+		flags = CTF_ADD_ROOT;
+	else
+		flags = CTF_ADD_NONROOT;
+
+	/*
+	 * ctf_add_forward tries to check to see if a given forward already
+	 * exists in one of its hash tables.  If we're here then we know that we
+	 * have a forward in a container that isn't present in another.
+	 * Therefore, we choose a token hash table to satisfy the API choice
+	 * here.
+	 */
+	ret = ctf_add_forward(cmp->cm_out, flags, name, CTF_K_STRUCT);
+	if (ret == CTF_ERR)
+		return (CTF_ERR);
+
+	VERIFY(cmp->cm_tmap[id].cmt_map == 0);
+	cmp->cm_tmap[id].cmt_map = ret;
+	return (0);
+}
+
+typedef struct ctf_merge_su {
+	ctf_merge_types_t *cms_cm;
+	ctf_id_t cms_id;
+} ctf_merge_su_t;
+
+static int
+ctf_merge_add_member(const char *name, ctf_id_t type, ulong_t offset, void *arg)
+{
+	ctf_merge_su_t *cms = arg;
+
+	VERIFY(cms->cms_cm->cm_tmap[type].cmt_map != 0);
+	type = cms->cms_cm->cm_tmap[type].cmt_map;
+
+	ctf_dprintf("Trying to add member %s to %d\n", name, cms->cms_id);
+	return (ctf_add_member(cms->cms_cm->cm_out, cms->cms_id, name,
+	    type, offset) == CTF_ERR);
+}
+
+/*
+ * During the first pass, we always add the generic structure and union but none
+ * of its members as they might not all have been mapped yet. Instead we just
+ * mark all structures and unions as needing to be fixed up.
+ */
+static int
+ctf_merge_add_sou(ctf_merge_types_t *cmp, ctf_id_t id, boolean_t forward)
+{
+	int flags, kind;
+	const ctf_type_t *tp;
+	const char *name;
+	ctf_id_t suid;
+
+	tp = LCTF_INDEX_TO_TYPEPTR(cmp->cm_src, id);
+	name = ctf_strraw(cmp->cm_src, tp->ctt_name);
+	if (CTF_INFO_ISROOT(tp->ctt_info) != 0)
+		flags = CTF_ADD_ROOT;
+	else
+		flags = CTF_ADD_NONROOT;
+	kind = ctf_type_kind(cmp->cm_src, id);
+
+	if (kind == CTF_K_STRUCT)
+		suid = ctf_add_struct(cmp->cm_out, flags, name);
+	else
+		suid = ctf_add_union(cmp->cm_out, flags, name);
+
+	if (suid == CTF_ERR)
+		return (suid);
+
+	/*
+	 * If this is a forward reference then its mapping should already
+	 * exist.
+	 */
+	if (forward == B_FALSE) {
+		VERIFY(cmp->cm_tmap[id].cmt_map == 0);
+		cmp->cm_tmap[id].cmt_map = suid;
+		ctf_dprintf("added sou \"%s\" as (%d) %d->%d\n", name, kind, id,
+		    suid);
+	} else {
+		VERIFY(cmp->cm_tmap[id].cmt_map == suid);
+	}
+	cmp->cm_tmap[id].cmt_fixup = B_TRUE;
+
+	return (0);
+}
+
+static int
+ctf_merge_add_type(ctf_merge_types_t *cmp, ctf_id_t id)
+{
+	int kind, ret;
+
+	/*
+	 * We may end up evaluating a type more than once as we may deal with it
+	 * as we recursively evaluate some kind of reference and then we may see
+	 * it normally.
+	 */
+	if (cmp->cm_tmap[id].cmt_map != 0)
+		return (0);
+
+	kind = ctf_type_kind(cmp->cm_src, id);
+	switch (kind) {
+	case CTF_K_INTEGER:
+	case CTF_K_FLOAT:
+		ret = ctf_merge_add_number(cmp, id);
+		break;
+	case CTF_K_ARRAY:
+		ret = ctf_merge_add_array(cmp, id);
+		break;
+	case CTF_K_POINTER:
+	case CTF_K_VOLATILE:
+	case CTF_K_CONST:
+	case CTF_K_RESTRICT:
+		ret = ctf_merge_add_reftype(cmp, id);
+		break;
+	case CTF_K_TYPEDEF:
+		ret = ctf_merge_add_typedef(cmp, id);
+		break;
+	case CTF_K_ENUM:
+		ret = ctf_merge_add_enum(cmp, id);
+		break;
+	case CTF_K_FUNCTION:
+		ret = ctf_merge_add_func(cmp, id);
+		break;
+	case CTF_K_FORWARD:
+		ret = ctf_merge_add_forward(cmp, id);
+		break;
+	case CTF_K_STRUCT:
+	case CTF_K_UNION:
+		ret = ctf_merge_add_sou(cmp, id, B_FALSE);
+		break;
+	case CTF_K_UNKNOWN:
+		/*
+		 * We don't add unknown types, and we later assert that nothing
+		 * should reference them.
+		 */
+		return (0);
+	default:
+		abort();
+	}
+
+	return (ret);
+}
+
+static int
+ctf_merge_fixup_sou(ctf_merge_types_t *cmp, ctf_id_t id)
+{
+	ctf_dtdef_t *dtd;
+	ctf_merge_su_t cms;
+	ctf_id_t mapid;
+	ssize_t size;
+
+	mapid = cmp->cm_tmap[id].cmt_map;
+	VERIFY(mapid != 0);
+	dtd = ctf_dtd_lookup(cmp->cm_out, mapid);
+	VERIFY(dtd != NULL);
+
+	ctf_dprintf("Trying to fix up sou %d\n", id);
+	cms.cms_cm = cmp;
+	cms.cms_id = mapid;
+	if (ctf_member_iter(cmp->cm_src, id, ctf_merge_add_member, &cms) != 0)
+		return (CTF_ERR);
+
+	if ((size = ctf_type_size(cmp->cm_src, id)) == CTF_ERR)
+		return (CTF_ERR);
+	if (ctf_set_size(cmp->cm_out, mapid, size) == CTF_ERR)
+		return (CTF_ERR);
+
+	return (0);
+}
+
+static int
+ctf_merge_fixup_type(ctf_merge_types_t *cmp, ctf_id_t id)
+{
+	int kind, ret;
+
+	kind = ctf_type_kind(cmp->cm_src, id);
+	switch (kind) {
+	case CTF_K_STRUCT:
+	case CTF_K_UNION:
+		ret = ctf_merge_fixup_sou(cmp, id);
+		break;
+	default:
+		VERIFY(0);
+		ret = CTF_ERR;
+	}
+
+	return (ret);
+}
+
+/*
+ * Now that we've successfully merged everything, we're going to clean
+ * up the merge type table. Traditionally if we had just two different
+ * files that we were working between, the types would be fully
+ * resolved. However, because we were comparing with ourself every step
+ * of the way and not our reduced self, we need to go through and update
+ * every mapped entry to what it now points to in the deduped file.
+ */
+static void
+ctf_merge_fixup_dedup_map(ctf_merge_types_t *cmp)
+{
+	int i;
+
+	for (i = 1; i < cmp->cm_src->ctf_typemax + 1; i++) {
+		ctf_id_t tid;
+
+		/*
+		 * Missing types always have their id updated to exactly what it
+		 * should be.
+		 */
+		if (cmp->cm_tmap[i].cmt_missing == B_TRUE) {
+			VERIFY(cmp->cm_tmap[i].cmt_map != 0);
+			continue;
+		}
+
+		tid = i;
+		while (cmp->cm_tmap[tid].cmt_missing == B_FALSE) {
+			VERIFY(cmp->cm_tmap[tid].cmt_map != 0);
+			tid = cmp->cm_tmap[tid].cmt_map;
+		}
+		VERIFY(cmp->cm_tmap[tid].cmt_map != 0);
+		cmp->cm_tmap[i].cmt_map = cmp->cm_tmap[tid].cmt_map;
+	}
+}
+
+
+/*
+ * We're going to do three passes over the containers.
+ *
+ * Pass 1 checks for forward references in the output container that we know
+ * exist in the source container.
+ *
+ * Pass 2 adds all the missing types from the source container. As part of this
+ * we may be adding a type as a forward reference that doesn't exist yet.
+ * Any types that we encounter in this form, we need to add to a third pass.
+ *
+ * Pass 3 is the fixup pass. Here we go through and find all the types that were
+ * missing in the first.
+ *
+ * Importantly, we *must* call ctf_update between the second and third pass,
+ * otherwise several of the libctf functions will not properly find the data in
+ * the container. If we're doing a dedup we also fix up the type mapping.
+ */
+static int
+ctf_merge_common(ctf_merge_types_t *cmp)
+{
+	int ret, i;
+
+	ctf_phase_dump(cmp->cm_src, "merge-common-src");
+	ctf_phase_dump(cmp->cm_out, "merge-common-dest");
+
+	/* Pass 1 */
+	for (i = 1; i <= cmp->cm_src->ctf_typemax; i++) {
+		if (cmp->cm_tmap[i].cmt_forward == B_TRUE) {
+			ret = ctf_merge_add_sou(cmp, i, B_TRUE);
+			if (ret != 0) {
+				return (ret);
+			}
+		}
+	}
+
+	/* Pass 2 */
+	for (i = 1; i <= cmp->cm_src->ctf_typemax; i++) {
+		if (cmp->cm_tmap[i].cmt_missing == B_TRUE) {
+			ret = ctf_merge_add_type(cmp, i);
+			if (ret != 0) {
+				ctf_dprintf("Failed to merge type %d\n", i);
+				return (ret);
+			}
+		}
+	}
+
+	ret = ctf_update(cmp->cm_out);
+	if (ret != 0)
+		return (ret);
+
+	if (cmp->cm_dedup == B_TRUE) {
+		ctf_merge_fixup_dedup_map(cmp);
+	}
+
+	ctf_dprintf("Beginning merge pass 3\n");
+	/* Pass 3 */
+	for (i = 1; i <= cmp->cm_src->ctf_typemax; i++) {
+		if (cmp->cm_tmap[i].cmt_fixup == B_TRUE) {
+			ret = ctf_merge_fixup_type(cmp, i);
+			if (ret != 0)
+				return (ret);
+		}
+	}
+
+	if (cmp->cm_dedup == B_TRUE) {
+		ctf_merge_fixup_dedup_map(cmp);
+	}
+
+	return (0);
+}
+
+/*
+ * Uniquification is slightly different from a stock merge. For starters, we
+ * don't need to replace any forward references in the output. In this case
+ * though, the types that already exist are in a parent container to the empty
+ * output container.
+ */
+static int
+ctf_merge_uniquify_types(ctf_merge_types_t *cmp)
+{
+	int i, ret;
+
+	for (i = 1; i <= cmp->cm_src->ctf_typemax; i++) {
+		if (cmp->cm_tmap[i].cmt_missing == B_FALSE)
+			continue;
+		ret = ctf_merge_add_type(cmp, i);
+		if (ret != 0)
+			return (ret);
+	}
+
+	ret = ctf_update(cmp->cm_out);
+	if (ret != 0)
+		return (ret);
+
+	for (i = 1; i <= cmp->cm_src->ctf_typemax; i++) {
+		if (cmp->cm_tmap[i].cmt_fixup == B_FALSE)
+			continue;
+		ret = ctf_merge_fixup_type(cmp, i);
+		if (ret != 0)
+			return (ret);
+	}
+
+	return (0);
+}
+
+static int
+ctf_merge_types_init(ctf_merge_types_t *cmp)
+{
+	cmp->cm_tmap = ctf_alloc(sizeof (ctf_merge_tinfo_t) *
+	    (cmp->cm_src->ctf_typemax + 1));
+	if (cmp->cm_tmap == NULL)
+		return (ctf_set_errno(cmp->cm_out, ENOMEM));
+	bzero(cmp->cm_tmap, sizeof (ctf_merge_tinfo_t) *
+	    (cmp->cm_src->ctf_typemax + 1));
+	return (0);
+}
+
+static void
+ctf_merge_types_fini(ctf_merge_types_t *cmp)
+{
+	ctf_free(cmp->cm_tmap, sizeof (ctf_merge_tinfo_t) *
+	    (cmp->cm_src->ctf_typemax + 1));
+}
+
+/*
+ * Merge the types contained inside of two input files. The second input file is
+ * always going to be the destination. We're guaranteed that it's always
+ * writeable.
+ */
+static int
+ctf_merge_types(void *arg, void *arg2, void **outp, void *unsued)
+{
+	int ret;
+	ctf_merge_types_t cm;
+	ctf_diff_t *cdp;
+	ctf_merge_objmap_t *cmo;
+	ctf_merge_funcmap_t *cmf;
+	ctf_merge_input_t *scmi = arg;
+	ctf_merge_input_t *dcmi = arg2;
+	ctf_file_t *out = dcmi->cmi_input;
+	ctf_file_t *source = scmi->cmi_input;
+
+	ctf_dprintf("merging %p->%p\n", source, out);
+
+	if (!(out->ctf_flags & LCTF_RDWR))
+		return (ctf_set_errno(out, ECTF_RDONLY));
+
+	if (ctf_getmodel(out) != ctf_getmodel(source))
+		return (ctf_set_errno(out, ECTF_DMODEL));
+
+	if ((ret = ctf_diff_init(out, source, &cdp)) != 0)
+		return (ret);
+
+	cm.cm_out = out;
+	cm.cm_src = source;
+	cm.cm_dedup = B_FALSE;
+	cm.cm_unique = B_FALSE;
+	ret = ctf_merge_types_init(&cm);
+	if (ret != 0) {
+		ctf_diff_fini(cdp);
+		return (ctf_set_errno(out, ret));
+	}
+
+	ret = ctf_diff_types(cdp, ctf_merge_diffcb, &cm);
+	if (ret != 0)
+		goto cleanup;
+	ret = ctf_merge_common(&cm);
+	ctf_dprintf("merge common returned with %d\n", ret);
+	if (ret == 0) {
+		ret = ctf_update(out);
+		ctf_dprintf("update returned with %d\n", ret);
+	} else {
+		goto cleanup;
+	}
+
+	/*
+	 * Now we need to fix up the object and function maps.
+	 */
+	for (cmo = list_head(&scmi->cmi_omap); cmo != NULL;
+	    cmo = list_next(&scmi->cmi_omap, cmo)) {
+		if (cmo->cmo_tid == 0)
+			continue;
+		VERIFY(cm.cm_tmap[cmo->cmo_tid].cmt_map != 0);
+		cmo->cmo_tid = cm.cm_tmap[cmo->cmo_tid].cmt_map;
+	}
+
+	for (cmf = list_head(&scmi->cmi_fmap); cmf != NULL;
+	    cmf = list_next(&scmi->cmi_fmap, cmf)) {
+		int i;
+
+		VERIFY(cm.cm_tmap[cmf->cmf_rtid].cmt_map != 0);
+		cmf->cmf_rtid = cm.cm_tmap[cmf->cmf_rtid].cmt_map;
+		for (i = 0; i < cmf->cmf_argc; i++) {
+			VERIFY(cm.cm_tmap[cmf->cmf_args[i]].cmt_map != 0);
+			cmf->cmf_args[i] = cm.cm_tmap[cmf->cmf_args[i]].cmt_map;
+		}
+	}
+
+	/*
+	 * Now that we've fixed things up, we need to give our function and
+	 * object maps to the destination, such that it can continue to update
+	 * them going forward.
+	 */
+	list_move_tail(&dcmi->cmi_fmap, &scmi->cmi_fmap);
+	list_move_tail(&dcmi->cmi_omap, &scmi->cmi_omap);
+
+cleanup:
+	if (ret == 0)
+		*outp = dcmi;
+	ctf_merge_types_fini(&cm);
+	ctf_diff_fini(cdp);
+	if (ret != 0)
+		return (ctf_errno(out));
+	return (0);
+}
+
+/*
+ * After performing a pass, we need to go through the object and function type
+ * maps and potentially fix them up based on the new maps that we haev.
+ */
+static void
+ctf_merge_fixup_nontypes(ctf_merge_types_t *cmp, ctf_merge_input_t *cmi)
+{
+	ctf_merge_objmap_t *cmo;
+	ctf_merge_funcmap_t *cmf;
+
+	for (cmo = list_head(&cmi->cmi_omap); cmo != NULL;
+	    cmo = list_next(&cmi->cmi_omap, cmo)) {
+		if (cmo->cmo_tid == 0)
+			continue;
+		VERIFY(cmp->cm_tmap[cmo->cmo_tid].cmt_map != 0);
+		cmo->cmo_tid = cmp->cm_tmap[cmo->cmo_tid].cmt_map;
+	}
+
+	for (cmf = list_head(&cmi->cmi_fmap); cmf != NULL;
+	    cmf = list_next(&cmi->cmi_fmap, cmf)) {
+		int i;
+
+		VERIFY(cmp->cm_tmap[cmf->cmf_rtid].cmt_map != 0);
+		cmf->cmf_rtid = cmp->cm_tmap[cmf->cmf_rtid].cmt_map;
+		for (i = 0; i < cmf->cmf_argc; i++) {
+			VERIFY(cmp->cm_tmap[cmf->cmf_args[i]].cmt_map !=
+			    0);
+			cmf->cmf_args[i] =
+			    cmp->cm_tmap[cmf->cmf_args[i]].cmt_map;
+		}
+	}
+}
+
+static int
+ctf_uniquify_types(ctf_merge_t *cmh, ctf_file_t *src, ctf_file_t **outp)
+{
+	int err, ret;
+	ctf_file_t *out;
+	ctf_merge_types_t cm;
+	ctf_diff_t *cdp;
+	ctf_merge_input_t *cmi;
+	ctf_file_t *parent = cmh->cmh_unique;
+
+	*outp = NULL;
+	out = ctf_fdcreate(cmh->cmh_ofd, &err);
+	if (out == NULL)
+		return (ctf_set_errno(src, err));
+
+	out->ctf_parname = cmh->cmh_pname;
+	if (ctf_setmodel(out, ctf_getmodel(parent)) != 0) {
+		(void) ctf_set_errno(src, ctf_errno(out));
+		ctf_close(out);
+		return (CTF_ERR);
+	}
+
+	if (ctf_import(out, parent) != 0) {
+		(void) ctf_set_errno(src, ctf_errno(out));
+		ctf_close(out);
+		return (CTF_ERR);
+	}
+
+	if ((ret = ctf_diff_init(parent, src, &cdp)) != 0) {
+		ctf_close(out);
+		return (ctf_set_errno(src, ctf_errno(parent)));
+	}
+
+	cm.cm_out = parent;
+	cm.cm_src = src;
+	cm.cm_dedup = B_FALSE;
+	cm.cm_unique = B_TRUE;
+	ret = ctf_merge_types_init(&cm);
+	if (ret != 0) {
+		ctf_close(out);
+		ctf_diff_fini(cdp);
+		return (ctf_set_errno(src, ret));
+	}
+
+	ret = ctf_diff_types(cdp, ctf_merge_diffcb, &cm);
+	if (ret == 0) {
+		cm.cm_out = out;
+		ret = ctf_merge_uniquify_types(&cm);
+		if (ret == 0)
+			ret = ctf_update(out);
+	}
+
+	if (ret != 0) {
+		ctf_merge_types_fini(&cm);
+		ctf_diff_fini(cdp);
+		return (ctf_set_errno(src, ctf_errno(cm.cm_out)));
+	}
+
+	for (cmi = list_head(&cmh->cmh_inputs); cmi != NULL;
+	    cmi = list_next(&cmh->cmh_inputs, cmi)) {
+		ctf_merge_fixup_nontypes(&cm, cmi);
+	}
+
+	ctf_merge_types_fini(&cm);
+	ctf_diff_fini(cdp);
+	*outp = out;
+	return (0);
+}
+
+static void
+ctf_merge_fini_input(ctf_merge_input_t *cmi)
+{
+	ctf_merge_objmap_t *cmo;
+	ctf_merge_funcmap_t *cmf;
+
+	while ((cmo = list_remove_head(&cmi->cmi_omap)) != NULL)
+		ctf_free(cmo, sizeof (ctf_merge_objmap_t));
+
+	while ((cmf = list_remove_head(&cmi->cmi_fmap)) != NULL)
+		ctf_free(cmf, sizeof (ctf_merge_funcmap_t) +
+		    sizeof (ctf_id_t) * cmf->cmf_argc);
+
+	if (cmi->cmi_created == B_TRUE && cmi->cmi_input != NULL)
+		ctf_close(cmi->cmi_input);
+
+	ctf_free(cmi, sizeof (ctf_merge_input_t));
+}
+
+void
+ctf_merge_fini(ctf_merge_t *cmh)
+{
+	size_t len;
+	ctf_merge_input_t *cmi;
+
+	if (cmh->cmh_label != NULL) {
+		len = strlen(cmh->cmh_label) + 1;
+		ctf_free(cmh->cmh_label, len);
+	}
+
+	if (cmh->cmh_pname != NULL) {
+		len = strlen(cmh->cmh_pname) + 1;
+		ctf_free(cmh->cmh_pname, len);
+	}
+
+	while ((cmi = list_remove_head(&cmh->cmh_inputs)) != NULL)
+		ctf_merge_fini_input(cmi);
+
+	ctf_free(cmh, sizeof (ctf_merge_t));
+}
+
+ctf_merge_t *
+ctf_merge_init(int fd, int *errp)
+{
+	int err;
+	ctf_merge_t *out;
+	struct stat st;
+
+	if (errp == NULL)
+		errp = &err;
+
+	if (fd != -1 && fstat(fd, &st) != 0) {
+		*errp = EINVAL;
+		return (NULL);
+	}
+
+	out = ctf_alloc(sizeof (ctf_merge_t));
+	if (out == NULL) {
+		*errp = ENOMEM;
+		return (NULL);
+	}
+
+	if (fd == -1) {
+		out->cmh_msyms = B_FALSE;
+	} else {
+		out->cmh_msyms = B_TRUE;
+	}
+
+	list_create(&out->cmh_inputs, sizeof (ctf_merge_input_t),
+	    offsetof(ctf_merge_input_t, cmi_node));
+	out->cmh_ninputs = 0;
+	out->cmh_nthreads = 1;
+	out->cmh_unique = NULL;
+	out->cmh_ofd = fd;
+	out->cmh_flags = 0;
+	out->cmh_label = NULL;
+	out->cmh_pname = NULL;
+
+	return (out);
+}
+
+int
+ctf_merge_label(ctf_merge_t *cmh, const char *label)
+{
+	char *dup;
+
+	if (label == NULL)
+		return (EINVAL);
+
+	dup = ctf_strdup(label);
+	if (dup == NULL)
+		return (EAGAIN);
+
+	if (cmh->cmh_label != NULL) {
+		size_t len = strlen(cmh->cmh_label) + 1;
+		ctf_free(cmh->cmh_label, len);
+	}
+
+	cmh->cmh_label = dup;
+	return (0);
+}
+
+static int
+ctf_merge_add_funcs_cb(const char *name, ulong_t idx, ctf_funcinfo_t *fip,
+    void *arg)
+{
+	ctf_merge_input_t *cmi = arg;
+	ctf_merge_funcmap_t *fmap;
+
+	fmap = ctf_alloc(sizeof (ctf_merge_funcmap_t) +
+	    sizeof (ctf_id_t) * fip->ctc_argc);
+	if (fmap == NULL)
+		return (ENOMEM);
+
+	fmap->cmf_idx = idx;
+	fmap->cmf_rtid = fip->ctc_return;
+	fmap->cmf_flags = fip->ctc_flags;
+	fmap->cmf_argc = fip->ctc_argc;
+	fmap->cmf_name = name;
+
+	if (ctf_func_args(cmi->cmi_input, idx, fmap->cmf_argc,
+	    fmap->cmf_args) != 0) {
+		ctf_free(fmap, sizeof (ctf_merge_funcmap_t) +
+		    sizeof (ctf_id_t) * fip->ctc_argc);
+		return (ctf_errno(cmi->cmi_input));
+	}
+
+	list_insert_tail(&cmi->cmi_fmap, fmap);
+	return (0);
+}
+
+static int
+ctf_merge_add_objs_cb(const char *name, ctf_id_t id, ulong_t idx, void *arg)
+{
+	ctf_merge_input_t *cmi = arg;
+	ctf_merge_objmap_t *cmo;
+
+	cmo = ctf_alloc(sizeof (ctf_merge_objmap_t));
+	if (cmo == NULL)
+		return (ENOMEM);
+
+	cmo->cmo_name = name;
+	cmo->cmo_idx = idx;
+	cmo->cmo_tid = id;
+	list_insert_tail(&cmi->cmi_omap, cmo);
+	return (0);
+}
+
+/*
+ * Whenever we create an entry to merge, we then go and add a second empty
+ * ctf_file_t which we use for the purposes of our merging. It's not the best,
+ * but it's the best that we've got at the moment.
+ */
+int
+ctf_merge_add(ctf_merge_t *cmh, ctf_file_t *input)
+{
+	int ret;
+	ctf_merge_input_t *cmi;
+	ctf_file_t *empty;
+
+	if (input->ctf_flags & LCTF_CHILD)
+		return (ECTF_MCHILD);
+
+	cmi = ctf_alloc(sizeof (ctf_merge_input_t));
+	if (cmi == NULL)
+		return (ENOMEM);
+
+	cmi->cmi_created = B_FALSE;
+	cmi->cmi_input = input;
+	list_create(&cmi->cmi_fmap, sizeof (ctf_merge_funcmap_t),
+	    offsetof(ctf_merge_funcmap_t, cmf_node));
+	list_create(&cmi->cmi_omap, sizeof (ctf_merge_funcmap_t),
+	    offsetof(ctf_merge_objmap_t, cmo_node));
+
+	if (cmh->cmh_msyms == B_TRUE) {
+		if ((ret = ctf_function_iter(input, ctf_merge_add_funcs_cb,
+		    cmi)) != 0) {
+			ctf_merge_fini_input(cmi);
+			return (ret);
+		}
+
+		if ((ret = ctf_object_iter(input, ctf_merge_add_objs_cb,
+		    cmi)) != 0) {
+			ctf_merge_fini_input(cmi);
+			return (ret);
+		}
+	}
+
+	list_insert_tail(&cmh->cmh_inputs, cmi);
+	cmh->cmh_ninputs++;
+
+	/* And now the empty one to merge into this */
+	cmi = ctf_alloc(sizeof (ctf_merge_input_t));
+	if (cmi == NULL)
+		return (ENOMEM);
+	list_create(&cmi->cmi_fmap, sizeof (ctf_merge_funcmap_t),
+	    offsetof(ctf_merge_funcmap_t, cmf_node));
+	list_create(&cmi->cmi_omap, sizeof (ctf_merge_funcmap_t),
+	    offsetof(ctf_merge_objmap_t, cmo_node));
+
+	empty = ctf_fdcreate(cmh->cmh_ofd, &ret);
+	if (empty == NULL)
+		return (ret);
+	cmi->cmi_input = empty;
+	cmi->cmi_created = B_TRUE;
+
+	if (ctf_setmodel(empty, ctf_getmodel(input)) == CTF_ERR) {
+		return (ctf_errno(empty));
+	}
+
+	list_insert_tail(&cmh->cmh_inputs, cmi);
+	cmh->cmh_ninputs++;
+	ctf_dprintf("added containers %p and %p\n", input, empty);
+	return (0);
+}
+
+int
+ctf_merge_uniquify(ctf_merge_t *cmh, ctf_file_t *u, const char *pname)
+{
+	char *dup;
+
+	if (u->ctf_flags & LCTF_CHILD)
+		return (ECTF_MCHILD);
+	if (pname == NULL)
+		return (EINVAL);
+	dup = ctf_strdup(pname);
+	if (dup == NULL)
+		return (EINVAL);
+	if (cmh->cmh_pname != NULL) {
+		size_t len = strlen(cmh->cmh_pname) + 1;
+		ctf_free(cmh->cmh_pname, len);
+	}
+	cmh->cmh_pname = dup;
+	cmh->cmh_unique = u;
+	return (0);
+}
+
+static int
+ctf_merge_symbols(ctf_merge_t *cmh, ctf_file_t *fp)
+{
+	int err;
+	ulong_t i;
+
+	uintptr_t symbase = (uintptr_t)fp->ctf_symtab.cts_data;
+	uintptr_t strbase = (uintptr_t)fp->ctf_strtab.cts_data;
+
+	for (i = 0; i < fp->ctf_nsyms; i++) {
+		const char *name;
+		ctf_merge_input_t *cmi;
+		ctf_merge_objmap_t *cmo;
+
+		if (fp->ctf_symtab.cts_entsize == sizeof (Elf32_Sym)) {
+			const Elf32_Sym *symp = (Elf32_Sym *)symbase + i;
+			int type = ELF32_ST_TYPE(symp->st_info);
+			if (type != STT_OBJECT)
+				continue;
+			if (ctf_sym_valid(strbase, type, symp->st_shndx,
+			    symp->st_value, symp->st_name) == B_FALSE)
+				continue;
+			name = (char *)(strbase + symp->st_name);
+		} else {
+			const Elf64_Sym *symp = (Elf64_Sym *)symbase + i;
+			int type = ELF64_ST_TYPE(symp->st_info);
+			if (type != STT_OBJECT)
+				continue;
+			if (ctf_sym_valid(strbase, type, symp->st_shndx,
+			    symp->st_value, symp->st_name) == B_FALSE)
+				continue;
+			name = (char *)(strbase + symp->st_name);
+		}
+
+		cmo = NULL;
+		for (cmi = list_head(&cmh->cmh_inputs); cmi != NULL;
+		    cmi = list_next(&cmh->cmh_inputs, cmi)) {
+			for (cmo = list_head(&cmi->cmi_omap); cmo != NULL;
+			    cmo = list_next(&cmi->cmi_omap, cmo)) {
+				if (strcmp(cmo->cmo_name, name) == 0)
+					goto found;
+			}
+		}
+found:
+		if (cmo != NULL) {
+			if (cmo->cmo_tid == 0)
+				continue;
+			if ((err = ctf_add_object(fp, i, cmo->cmo_tid)) != 0) {
+				ctf_dprintf("Failed to add symbol %s->%d: %s\n",
+				    name, cmo->cmo_tid,
+				    ctf_errmsg(ctf_errno(fp)));
+				return (err);
+			}
+		}
+	}
+
+	return (0);
+}
+
+static int
+ctf_merge_functions(ctf_merge_t *cmh, ctf_file_t *fp)
+{
+	int err;
+	ulong_t i;
+	ctf_funcinfo_t fi;
+
+	uintptr_t symbase = (uintptr_t)fp->ctf_symtab.cts_data;
+	uintptr_t strbase = (uintptr_t)fp->ctf_strtab.cts_data;
+
+	for (i = 0; i < fp->ctf_nsyms; i++) {
+		const char *name;
+		ctf_merge_input_t *cmi;
+		ctf_merge_funcmap_t *cmf;
+
+		if (fp->ctf_symtab.cts_entsize == sizeof (Elf32_Sym)) {
+			const Elf32_Sym *symp = (Elf32_Sym *)symbase + i;
+			int type = ELF32_ST_TYPE(symp->st_info);
+			if (ELF32_ST_TYPE(symp->st_info) != STT_FUNC)
+				continue;
+			if (ctf_sym_valid(strbase, type, symp->st_shndx,
+			    symp->st_value, symp->st_name) == B_FALSE)
+				continue;
+			name = (char *)(strbase + symp->st_name);
+		} else {
+			const Elf64_Sym *symp = (Elf64_Sym *)symbase + i;
+			int type = ELF64_ST_TYPE(symp->st_info);
+			if (ELF64_ST_TYPE(symp->st_info) != STT_FUNC)
+				continue;
+			if (ctf_sym_valid(strbase, type, symp->st_shndx,
+			    symp->st_value, symp->st_name) == B_FALSE)
+				continue;
+			name = (char *)(strbase + symp->st_name);
+		}
+
+		cmf = NULL;
+		for (cmi = list_head(&cmh->cmh_inputs); cmi != NULL;
+		    cmi = list_next(&cmh->cmh_inputs, cmi)) {
+			for (cmf = list_head(&cmi->cmi_fmap); cmf != NULL;
+			    cmf = list_next(&cmi->cmi_fmap, cmf)) {
+				if (strcmp(cmf->cmf_name, name) == 0)
+					goto found;
+			}
+		}
+found:
+		if (cmf != NULL) {
+			fi.ctc_return = cmf->cmf_rtid;
+			fi.ctc_argc = cmf->cmf_argc;
+			fi.ctc_flags = cmf->cmf_flags;
+			if ((err = ctf_add_function(fp, i, &fi,
+			    cmf->cmf_args)) != 0)
+				return (err);
+		}
+	}
+
+	return (0);
+
+}
+
+int
+ctf_merge_merge(ctf_merge_t *cmh, ctf_file_t **outp)
+{
+	int err, merr;
+	ctf_merge_input_t *cmi;
+	ctf_id_t ltype;
+	mergeq_t *mqp;
+	ctf_merge_input_t *final;
+	ctf_file_t *out;
+
+	if (cmh->cmh_label != NULL && cmh->cmh_unique != NULL) {
+		const char *label = ctf_label_topmost(cmh->cmh_unique);
+		if (label == NULL)
+			return (ECTF_NOLABEL);
+		if (strcmp(label, cmh->cmh_label) != 0)
+			return (ECTF_LCONFLICT);
+	}
+
+	if (mergeq_init(&mqp, cmh->cmh_nthreads) == -1) {
+		return (errno);
+	}
+
+	VERIFY(cmh->cmh_ninputs % 2 == 0);
+	for (cmi = list_head(&cmh->cmh_inputs); cmi != NULL;
+	    cmi = list_next(&cmh->cmh_inputs, cmi)) {
+		if (mergeq_add(mqp, cmi) == -1) {
+			err = errno;
+			mergeq_fini(mqp);
+		}
+	}
+
+	err = mergeq_merge(mqp, ctf_merge_types, NULL, (void **)&final, &merr);
+	mergeq_fini(mqp);
+
+	if (err == MERGEQ_ERROR) {
+		return (errno);
+	} else if (err == MERGEQ_UERROR) {
+		return (merr);
+	}
+
+	/*
+	 * Disassociate the generated ctf_file_t from the original input. That
+	 * way when the input gets cleaned up, we don't accidentally kill the
+	 * final reference to the ctf_file_t. If it gets uniquified then we'll
+	 * kill it.
+	 */
+	VERIFY(final->cmi_input != NULL);
+	out = final->cmi_input;
+	final->cmi_input = NULL;
+
+	ctf_dprintf("preparing to uniquify against: %p\n", cmh->cmh_unique);
+	if (cmh->cmh_unique != NULL) {
+		ctf_file_t *u;
+		err = ctf_uniquify_types(cmh, out, &u);
+		if (err != 0) {
+			err = ctf_errno(out);
+			ctf_close(out);
+			return (err);
+		}
+		ctf_close(out);
+		out = u;
+	}
+
+	ltype = out->ctf_typemax;
+	if ((out->ctf_flags & LCTF_CHILD) && ltype != 0)
+		ltype += CTF_CHILD_START;
+	ctf_dprintf("trying to add the label\n");
+	if (cmh->cmh_label != NULL &&
+	    ctf_add_label(out, cmh->cmh_label, ltype, 0) != 0) {
+		ctf_close(out);
+		return (ctf_errno(out));
+	}
+
+	ctf_dprintf("merging symbols and the like\n");
+	if (cmh->cmh_msyms == B_TRUE) {
+		err = ctf_merge_symbols(cmh, out);
+		if (err != 0) {
+			ctf_close(out);
+			return (ctf_errno(out));
+		}
+
+		err = ctf_merge_functions(cmh, out);
+		if (err != 0) {
+			ctf_close(out);
+			return (ctf_errno(out));
+		}
+	}
+
+	err = ctf_update(out);
+	if (err != 0) {
+		ctf_close(out);
+		return (ctf_errno(out));
+	}
+
+	*outp = out;
+	return (0);
+}
+
+/*
+ * When we get told that something is unique, eg. same is B_FALSE, then that
+ * tells us that we need to add it to the output. If same is B_TRUE, then we'll
+ * want to record it in the mapping table so that we know how to redirect types
+ * to the extant ones.
+ */
+static void
+ctf_dedup_cb(ctf_file_t *ifp, ctf_id_t iid, boolean_t same, ctf_file_t *ofp,
+    ctf_id_t oid, void *arg)
+{
+	ctf_merge_types_t *cmp = arg;
+	ctf_merge_tinfo_t *cmt = cmp->cm_tmap;
+
+	if (same == B_TRUE) {
+		/*
+		 * The output id here may itself map to something else.
+		 * Therefore, we need to basically walk a chain and see what it
+		 * points to until it itself points to a base type, eg. -1.
+		 * Otherwise we'll dedup to something which no longer exists.
+		 */
+		while (cmt[oid].cmt_missing == B_FALSE)
+			oid = cmt[oid].cmt_map;
+		cmt[iid].cmt_map = oid;
+		ctf_dprintf("%d->%d \n", iid, oid);
+	} else {
+		VERIFY(cmt[iid].cmt_map == 0);
+		cmt[iid].cmt_missing = B_TRUE;
+		ctf_dprintf("%d is missing\n", iid);
+	}
+}
+
+/*
+ * Dedup a CTF container.
+ *
+ * DWARF and other encoding formats that we use to create CTF data may create
+ * multiple copies of a given type. However, after doing a conversion, and
+ * before doing a merge, we'd prefer, if possible, to have every input container
+ * to be unique.
+ *
+ * Doing a deduplication is like a normal merge. However, when we diff the types
+ * in the container, rather than doing a normal diff, we instead want to diff
+ * against any already processed types. eg, for a given type i in a container,
+ * we want to diff it from 0 to i - 1.
+ */
+int
+ctf_merge_dedup(ctf_merge_t *cmp, ctf_file_t **outp)
+{
+	int ret;
+	ctf_diff_t *cdp = NULL;
+	ctf_merge_input_t *cmi, *cmc;
+	ctf_file_t *ifp, *ofp;
+	ctf_merge_types_t cm;
+
+	if (cmp == NULL || outp == NULL)
+		return (EINVAL);
+
+	ctf_dprintf("encountered %d inputs\n", cmp->cmh_ninputs);
+	if (cmp->cmh_ninputs != 2)
+		return (EINVAL);
+
+	ctf_dprintf("passed argument sanity check\n");
+
+	cmi = list_head(&cmp->cmh_inputs);
+	VERIFY(cmi != NULL);
+	cmc = list_next(&cmp->cmh_inputs, cmi);
+	VERIFY(cmc != NULL);
+	ifp = cmi->cmi_input;
+	ofp = cmc->cmi_input;
+	VERIFY(ifp != NULL);
+	VERIFY(ofp != NULL);
+	cm.cm_src = ifp;
+	cm.cm_out = ofp;
+	cm.cm_dedup = B_TRUE;
+	cm.cm_unique = B_FALSE;
+
+	if ((ret = ctf_merge_types_init(&cm)) != 0) {
+		return (ret);
+	}
+
+	if ((ret = ctf_diff_init(ifp, ifp, &cdp)) != 0)
+		goto err;
+
+	ctf_dprintf("Successfully initialized dedup\n");
+	if ((ret = ctf_diff_self(cdp, ctf_dedup_cb, &cm)) != 0)
+		goto err;
+
+	ctf_dprintf("Successfully diffed types\n");
+	ret = ctf_merge_common(&cm);
+	ctf_dprintf("deduping types result: %d\n", ret);
+	if (ret == 0)
+		ret = ctf_update(cm.cm_out);
+	if (ret != 0)
+		goto err;
+
+	ctf_dprintf("Successfully deduped types\n");
+	ctf_phase_dump(cm.cm_out, "dedup-pre-syms");
+
+	/*
+	 * Now we need to fix up the object and function maps.
+	 */
+	ctf_merge_fixup_nontypes(&cm, cmi);
+
+	if (cmp->cmh_msyms == B_TRUE) {
+		ret = ctf_merge_symbols(cmp, cm.cm_out);
+		if (ret != 0) {
+			ret = ctf_errno(cm.cm_out);
+			ctf_dprintf("failed to dedup symbols: %s\n",
+			    ctf_errmsg(ret));
+			goto err;
+		}
+
+		ret = ctf_merge_functions(cmp, cm.cm_out);
+		if (ret != 0) {
+			ret = ctf_errno(cm.cm_out);
+			ctf_dprintf("failed to dedup functions: %s\n",
+			    ctf_errmsg(ret));
+			goto err;
+		}
+	}
+
+	ret = ctf_update(cm.cm_out);
+	if (ret == 0) {
+		cmc->cmi_input = NULL;
+		*outp = cm.cm_out;
+	}
+err:
+	ctf_merge_types_fini(&cm);
+	ctf_diff_fini(cdp);
+	return (ret);
+}
+
+int
+ctf_merge_set_nthreads(ctf_merge_t *cmp, const uint_t nthrs)
+{
+	if (nthrs == 0)
+		return (EINVAL);
+	cmp->cmh_nthreads = nthrs;
+	return (0);
+}