11267 Add rust demangling support

Reviewed by: Michal Nowak <mnowak@startmail.com>
Reviewed by: Toomas Soome <tsoome@me.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

27 files changed, 1237 insertions, 91 deletions

diff --git a/usr/src/cmd/dis/dis_util.c b/usr/src/cmd/dis/dis_util.c
index f74e7cef67..af38189cb4 100644
--- a/usr/src/cmd/dis/dis_util.c
+++ b/usr/src/cmd/dis/dis_util.c
@@ -24,6 +24,7 @@
  * Use is subject to license terms.
  *
  * Copyright 2018 Jason King.
+ * Copyright 2018, Joyent, Inc.
  */
 
 #include <dlfcn.h>
@@ -106,6 +107,6 @@ dis_demangle(const char *name)
 	 * from previous invocations is freed.
 	 */
 	free(demangled_name);
-	demangled_name = sysdemangle(name, SYSDEM_LANG_CPP, NULL);
+	demangled_name = sysdemangle(name, SYSDEM_LANG_AUTO, NULL);
 	return ((demangled_name != NULL) ? demangled_name : name);
 }
diff --git a/usr/src/cmd/mdb/common/mdb/mdb_cmds.c b/usr/src/cmd/mdb/common/mdb/mdb_cmds.c
index dd3f9cd11e..fff03274d5 100644
--- a/usr/src/cmd/mdb/common/mdb/mdb_cmds.c
+++ b/usr/src/cmd/mdb/common/mdb/mdb_cmds.c
@@ -3207,8 +3207,8 @@ const mdb_dcmd_t mdb_dcmd_builtins[] = {
 	 */
 	{ "?", "fmt-list", "format data from object file", cmd_print_object },
 	{ "$>", "[file]", "log session to a file", cmd_old_log },
-	{ "$g", "?", "get/set C++ demangling options", cmd_demflags },
-	{ "$G", NULL, "enable/disable C++ demangling support", cmd_demangle },
+	{ "$g", "?", "get/set demangling options", cmd_demflags },
+	{ "$G", NULL, "enable/disable demangling support", cmd_demangle },
 	{ "$i", NULL, "print signals that are ignored", cmd_notsup },
 	{ "$l", NULL, "print the representative thread's lwp id", cmd_notsup },
 	{ "$p", ":", "change debugger target context", cmd_context },
diff --git a/usr/src/cmd/mdb/common/mdb/mdb_demangle.c b/usr/src/cmd/mdb/common/mdb/mdb_demangle.c
index ad7555dcc0..94386d5f66 100644
--- a/usr/src/cmd/mdb/common/mdb/mdb_demangle.c
+++ b/usr/src/cmd/mdb/common/mdb/mdb_demangle.c
@@ -26,6 +26,10 @@
  * Copyright 2018 Jason King
  */
 
+/*
+ * Copyright (c) 2019, Joyent, Inc.  All rights reserved.
+ */
+
 #include <mdb/mdb_modapi.h>
 #include <mdb/mdb_demangle.h>
 #include <mdb/mdb_err.h>
@@ -62,8 +66,7 @@ mdb_dem_load(void)
 	dmp->dm_len = 0;
 	dmp->dm_buf = NULL;
 	dmp->dm_flags = MDB_DM_SCOPE;
-	/* stick with C++ for now to match old behavior */
-	dmp->dm_lang = SYSDEM_LANG_CPP;
+	dmp->dm_lang = SYSDEM_LANG_AUTO;
 
 	return (dmp);
 }
@@ -207,7 +210,20 @@ mdb_dem_process(mdb_demangler_t *dmp, const char *name)
 
 	res = sysdemangle(name + prefixlen, dmp->dm_lang, &mdb_dem_demops);
 	if (res == NULL) {
-		if (errno != EINVAL)
+		/*
+		 * EINVAL indicates the name is not a properly mangled name
+		 * (or perhaps is truncated so it cannot be correctly
+		 * demangled) while ENOTSUP means sysdemangle could not
+		 * determine which language was used to mangle the name when
+		 * SYSDEM_LANG_AUTO is used (the name might not be mangled,
+		 * the name could be truncated enough to prevent determination
+		 * of the name, etc).
+		 *
+		 * Both are allowed/expected failure modes, so in both cases
+		 * do not emit a warning -- let the caller display the
+		 * original name.
+		 */
+		if (errno != EINVAL && errno != ENOTSUP)
 			mdb_warn("Error while demangling");
 		return (-1);
 	}
diff --git a/usr/src/cmd/sgs/elfdump/common/elfdump.msg b/usr/src/cmd/sgs/elfdump/common/elfdump.msg
index 253ea4a788..5876b59f1f 100644
--- a/usr/src/cmd/sgs/elfdump/common/elfdump.msg
+++ b/usr/src/cmd/sgs/elfdump/common/elfdump.msg
@@ -37,7 +37,7 @@
 			 [-N name] [-O osabi] [-T type] [-p | -w outfile] \
 			 file...\n"
 @ MSG_USAGE_DETAIL1	"\t[-c]\t\tdump section header information\n"
-@ MSG_USAGE_DETAIL2	"\t[-C]\t\tdemangle C++ symbol names\n"
+@ MSG_USAGE_DETAIL2	"\t[-C]\t\tdemangle symbol names\n"
 @ MSG_USAGE_DETAIL3	"\t[-d]\t\tdump the contents of the .dynamic section\n"
 @ MSG_USAGE_DETAIL4	"\t[-e]\t\tdump the elf header\n"
 @ MSG_USAGE_DETAIL5	"\t[-g]\t\tdump the contents of the .group sections\n"
diff --git a/usr/src/cmd/sgs/pvs/common/pvs.c b/usr/src/cmd/sgs/pvs/common/pvs.c
index 4d51ce300d..5a53021e09 100644
--- a/usr/src/cmd/sgs/pvs/common/pvs.c
+++ b/usr/src/cmd/sgs/pvs/common/pvs.c
@@ -22,12 +22,13 @@
 /*
  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
+ * Copyright 2019 Joyent, Inc.
  */
 
 /*
  * Analyze the versioning information within a file.
  *
- *   -C		demangle C++ symbol names.
+ *   -C		demangle symbol names.
  *
  *   -d		dump version definitions.
  *
@@ -91,7 +92,7 @@ typedef struct gver_desc {
 
 /* Versym related data used by gvers_syms() */
 typedef struct {
-	GElf_Versym	*vsd_vsp;   	/* ptr to versym data */
+	GElf_Versym	*vsd_vsp;	/* ptr to versym data */
 	Elf_Data	*vsd_sym_data;	/* ptr to symtab data */
 	Word		vsd_symn;	/* # of symbols in symtab */
 	const char	*vsd_strs;	/* string table data */
@@ -710,7 +711,7 @@ gvers_find(const char *name, unsigned long hash, APlist *lst)
  *
  * exit:
  *	Return the corresponding GVer_desc struct. If the
- * 	descriptor does not already exist, it is created.
+ *	descriptor does not already exist, it is created.
  *	On error, a fatal error is issued and the process exits.
  */
 static GVer_desc *
@@ -766,7 +767,7 @@ static void
 gvers_derefer(GVer_desc *vdp, int weak)
 {
 	Aliste		idx;
-	GVer_desc 	*_vdp;
+	GVer_desc	*_vdp;
 
 	/*
 	 * If the head of the list was a weak then we only clear out
@@ -874,7 +875,7 @@ gvers_def(Cache *cache, Cache *def, const Gver_sym_data *vsdata,
 	if (nflag) {
 		for (APLIST_TRAVERSE(verdefs, idx1, vdp)) {
 			Aliste		idx2;
-			GVer_desc 	*_vdp;
+			GVer_desc	*_vdp;
 			int		type = vdp->vd_flags & VER_FLG_WEAK;
 
 			for (APLIST_TRAVERSE(vdp->vd_deps, idx2, _vdp))
@@ -895,7 +896,7 @@ gvers_def(Cache *cache, Cache *def, const Gver_sym_data *vsdata,
 	 */
 	for (APLIST_TRAVERSE(verdefs, idx1, vdp)) {
 		Aliste		idx2;
-		GVer_desc 	*_vdp;
+		GVer_desc	*_vdp;
 		int		count;
 
 		if (!match(NULL, vdp->vd_name, vdp->vd_ndx))
@@ -1006,13 +1007,13 @@ main(int argc, char **argv, char **envp)
 	Elf		*elf;
 	Elf_Scn		*scn;
 	Elf_Data	*data;
-	GElf_Ehdr 	ehdr;
+	GElf_Ehdr	ehdr;
 	int		nfile, var;
 	char		*names;
 	Cache		*cache, *_cache;
 	Cache		*_cache_def, *_cache_need, *_cache_sym, *_cache_loc;
 	int		error = 0;
-	Gver_sym_data 	vsdata_s;
+	Gver_sym_data	vsdata_s;
 	const Gver_sym_data	*vsdata = NULL;
 
 	/*
diff --git a/usr/src/cmd/sgs/pvs/common/pvs.msg b/usr/src/cmd/sgs/pvs/common/pvs.msg
index 82a61385cd..eb888a753a 100644
--- a/usr/src/cmd/sgs/pvs/common/pvs.msg
+++ b/usr/src/cmd/sgs/pvs/common/pvs.msg
@@ -22,6 +22,7 @@
 #
 # Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 # Use is subject to license terms.
+# Copyright 2018, Joyent, Inc.
 #
 
 @ _START_
@@ -34,7 +35,7 @@
 # Argument usage messages.
 
 @ MSG_USAGE_BRIEF	"usage: %s [-Cdlnorsv] [-I index] [-N Name] file(s)\n"
-@ MSG_USAGE_DETAIL	"\t[-C]\t\tdemangle C++ symbol names\n\
+@ MSG_USAGE_DETAIL	"\t[-C]\t\tdemangle symbol names\n\
 			 \t[-d]\t\tprint version definition information\n\
 			 \t[-I index]\tqualify version with an index\n\
 			 \t[-l]\t\tprint reduced symbols\n\
diff --git a/usr/src/lib/Makefile b/usr/src/lib/Makefile
index a5b8ab9e57..002501f668 100644
--- a/usr/src/lib/Makefile
+++ b/usr/src/lib/Makefile
@@ -596,6 +596,7 @@ libcmdutils:	libavl
 libcpc:		libpctx
 libcrypt:	libgen
 libctf:		libdwarf
+libdemangle:	libcustr
 libdevid:	libdevinfo
 libdevinfo:	libsec libgen
 libdhcpagent:	libdhcputil libuuid libdlpi libcontract
diff --git a/usr/src/lib/libdemangle/Makefile.com b/usr/src/lib/libdemangle/Makefile.com
index 0b0d495df7..7eba05ce1c 100644
--- a/usr/src/lib/libdemangle/Makefile.com
+++ b/usr/src/lib/libdemangle/Makefile.com
@@ -16,12 +16,12 @@
 
 LIBRARY = libdemangle-sys.a
 VERS    = .1
-OBJECTS = str.o util.o cxx_util.o cxx.o demangle.o
+OBJECTS = str.o strview.o util.o cxx_util.o cxx.o demangle.o rust.o
 
 include ../../Makefile.lib
 
 LIBS =		$(DYNLIB) $(LINTLIB)
-LDLIBS +=	-lc
+LDLIBS +=	-lc -lcustr
 
 SRCDIR =	../common
 $(LINTLIB) :=	SRCS = $(SRCDIR)/$(LINTSRC)
diff --git a/usr/src/lib/libdemangle/common/cxx.c b/usr/src/lib/libdemangle/common/cxx.c
index e3b4c06a8a..af5f549f78 100644
--- a/usr/src/lib/libdemangle/common/cxx.c
+++ b/usr/src/lib/libdemangle/common/cxx.c
@@ -165,11 +165,10 @@ static const char *parse_vector_type(const char *, const char *, cpp_db_t *);
 size_t cpp_name_max_depth = 1024;	/* max depth of name stack */
 
 char *
-cpp_demangle(const char *src, sysdem_ops_t *ops)
+cpp_demangle(const char *src, size_t srclen, sysdem_ops_t *ops)
 {
 	char *result = NULL;
 	cpp_db_t db;
-	size_t srclen = strlen(src);
 
 	if (!db_init(&db, ops))
 		goto done;
diff --git a/usr/src/lib/libdemangle/common/demangle-sys.h b/usr/src/lib/libdemangle/common/demangle-sys.h
index 02636c9521..05776ee5ee 100644
--- a/usr/src/lib/libdemangle/common/demangle-sys.h
+++ b/usr/src/lib/libdemangle/common/demangle-sys.h
@@ -11,6 +11,7 @@
 
 /*
  * Copyright 2017 Jason King
+ * Copyright 2018, Joyent, Inc.
  */
 
 #ifndef _DEMANGLE_SYS_H
@@ -24,7 +25,8 @@ extern "C" {
 
 typedef enum sysdem_lang_e {
 	SYSDEM_LANG_AUTO,
-	SYSDEM_LANG_CPP
+	SYSDEM_LANG_CPP,
+	SYSDEM_LANG_RUST
 } sysdem_lang_t;
 
 typedef struct sysdem_alloc_s {
diff --git a/usr/src/lib/libdemangle/common/demangle.c b/usr/src/lib/libdemangle/common/demangle.c
index e827fd8cec..4f8e9ad678 100644
--- a/usr/src/lib/libdemangle/common/demangle.c
+++ b/usr/src/lib/libdemangle/common/demangle.c
@@ -11,13 +11,17 @@
 
 /*
  * Copyright 2018 Jason King
+ * Copyright 2019, Joyent, Inc.
  */
 
 #include <stdlib.h>
+#include <stdio.h>
 #include <string.h>
 #include <errno.h>
 #include <pthread.h>
+#include <sys/ctype.h>
 #include <sys/debug.h>
+#include <stdarg.h>
 #include "demangle-sys.h"
 #include "demangle_int.h"
 
@@ -25,31 +29,63 @@
 
 static pthread_once_t debug_once = PTHREAD_ONCE_INIT;
 volatile boolean_t demangle_debug;
+FILE *debugf = stderr;
+
+static const char *
+langstr(sysdem_lang_t lang)
+{
+	switch (lang) {
+	case SYSDEM_LANG_AUTO:
+		return ("auto");
+	case SYSDEM_LANG_CPP:
+		return ("c++");
+	case SYSDEM_LANG_RUST:
+		return ("rust");
+	default:
+		return ("invalid");
+	}
+}
 
 static sysdem_lang_t
-detect_lang(const char *str)
+detect_lang(const char *str, size_t n)
 {
-	size_t n = strlen(str);
+	const char *p = str;
+	size_t len;
 
 	if (n < 3 || str[0] != '_')
 		return (SYSDEM_LANG_AUTO);
 
-	switch (str[1]) {
-	case 'Z':
+	/*
+	 * Check for ^_Z or ^__Z
+	 */
+	p = str + 1;
+	if (*p == '_') {
+		p++;
+	}
+
+	if (*p != 'Z')
+		return (SYSDEM_LANG_AUTO);
+
+	/*
+	 * Sadly, rust currently uses the same prefix as C++, however
+	 * demangling rust as a C++ mangled name yields less than desirable
+	 * results.  However rust names end with a hash.  We use that to
+	 * attempt to disambiguate
+	 */
+
+	/* Find 'h'<hexdigit>+E$ */
+	if ((p = strrchr(p, 'h')) == NULL)
 		return (SYSDEM_LANG_CPP);
 
-	case '_':
-		break;
+	if ((len = strspn(p + 1, "0123456789abcdef")) == 0)
+		return (SYSDEM_LANG_CPP);
 
-	default:
-		return (SYSDEM_LANG_AUTO);
-	}
+	p += len + 1;
 
-	/* why they use ___Z sometimes is puzzling... *sigh* */
-	if (str[2] == '_' && str[3] == 'Z')
+	if (p[0] != 'E' || p[1] != '\0')
 		return (SYSDEM_LANG_CPP);
 
-	return (SYSDEM_LANG_AUTO);
+	return (SYSDEM_LANG_RUST);
 }
 
 static void
@@ -62,26 +98,76 @@ check_debug(void)
 char *
 sysdemangle(const char *str, sysdem_lang_t lang, sysdem_ops_t *ops)
 {
+	/*
+	 * While the language specific demangler code can handle non-NUL
+	 * terminated strings, we currently don't expose this to consumers.
+	 * Consumers should still pass in a NUL-terminated string.
+	 */
+	size_t slen;
+
 	VERIFY0(pthread_once(&debug_once, check_debug));
 
+	DEMDEBUG("name = '%s'", (str == NULL) ? "(NULL)" : str);
+	DEMDEBUG("lang = %s (%d)", langstr(lang), lang);
+
+	if (str == NULL) {
+		errno = EINVAL;
+		return (NULL);
+	}
+
+	slen = strlen(str);
+
+	switch (lang) {
+		case SYSDEM_LANG_AUTO:
+		case SYSDEM_LANG_CPP:
+		case SYSDEM_LANG_RUST:
+			break;
+		default:
+			errno = EINVAL;
+			return (NULL);
+	}
+
 	if (ops == NULL)
 		ops = sysdem_ops_default;
 
 	if (lang == SYSDEM_LANG_AUTO) {
-		lang = detect_lang(str);
-		if (lang == SYSDEM_LANG_AUTO) {
-			errno = ENOTSUP;
-			return (NULL);
-		}
+		lang = detect_lang(str, slen);
+		if (lang != SYSDEM_LANG_AUTO)
+			DEMDEBUG("detected language is %s", langstr(lang));
 	}
 
 	switch (lang) {
-	case SYSDEM_LANG_AUTO:
-		break;
 	case SYSDEM_LANG_CPP:
-		return (cpp_demangle(str, ops));
+		return (cpp_demangle(str, slen, ops));
+	case SYSDEM_LANG_RUST:
+		return (rust_demangle(str, slen, ops));
+	case SYSDEM_LANG_AUTO:
+		DEMDEBUG("could not detect language");
+		errno = ENOTSUP;
+		return (NULL);
+	default:
+		/*
+		 * This can't happen unless there's a bug with detect_lang,
+		 * but gcc doesn't know that.
+		 */
+		errno = EINVAL;
+		return (NULL);
 	}
+}
 
-	errno = ENOTSUP;
-	return (NULL);
+int
+demdebug(const char *fmt, ...)
+{
+	va_list ap;
+
+	flockfile(debugf);
+	(void) fprintf(debugf, "LIBDEMANGLE: ");
+	va_start(ap, fmt);
+	(void) vfprintf(debugf, fmt, ap);
+	(void) fputc('\n', debugf);
+	(void) fflush(debugf);
+	va_end(ap);
+	funlockfile(debugf);
+
+	return (0);
 }
diff --git a/usr/src/lib/libdemangle/common/demangle_int.h b/usr/src/lib/libdemangle/common/demangle_int.h
index 9abb2cc295..66a34cf41d 100644
--- a/usr/src/lib/libdemangle/common/demangle_int.h
+++ b/usr/src/lib/libdemangle/common/demangle_int.h
@@ -11,6 +11,7 @@
 
 /*
  * Copyright 2017 Jason King
+ * Copyright 2019, Joyent, Inc.
  */
 #ifndef _DEMANGLE_INT_H
 #define	_DEMANGLE_INT_H
@@ -24,14 +25,26 @@ extern "C" {
 
 extern sysdem_ops_t *sysdem_ops_default;
 
-char *cpp_demangle(const char *, sysdem_ops_t *);
+char *cpp_demangle(const char *, size_t, sysdem_ops_t *);
+char *rust_demangle(const char *, size_t, sysdem_ops_t *);
 
 void *zalloc(sysdem_ops_t *, size_t);
 void *xrealloc(sysdem_ops_t *, void *, size_t, size_t);
 void xfree(sysdem_ops_t *, void *, size_t);
+char *xstrdup(sysdem_ops_t *, const char *);
 
 extern volatile boolean_t demangle_debug;
 
+/*
+ * gcc seems to get unhappy with the ASSERT() style definition (also borrowed
+ * for the DEMDEBUG macro unless demdebug() is returns a non-void value
+ * (despite the return value never being used).
+ */
+int demdebug(const char *, ...);
+
+#define	DEMDEBUG(s, ...) \
+	((void)(demangle_debug && demdebug(s, ## __VA_ARGS__)))
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/usr/src/lib/libdemangle/common/rust.c b/usr/src/lib/libdemangle/common/rust.c
new file mode 100644
index 0000000000..f99fe79a10
--- /dev/null
+++ b/usr/src/lib/libdemangle/common/rust.c
@@ -0,0 +1,543 @@
+/*
+ * 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 2019, Joyent, Inc.
+ */
+
+#include <errno.h>
+#include <libcustr.h>
+#include <limits.h>
+#include <string.h>
+#include <sys/ctype.h>	/* We want the C locale ISXXX() versions */
+#include <sys/debug.h>
+#include <stdio.h>
+#include <sys/sysmacros.h>
+
+#include "strview.h"
+#include "demangle_int.h"
+
+/*
+ * Unfortunately, there is currently no official specification for the rust
+ * name mangling.  This is an attempt to document the understanding of the
+ * mangling used here.  It is based off examination of
+ *     https://docs.rs/rustc-demangle/0.1.13/rustc_demangle/
+ *
+ * A mangled rust name is:
+ *     <prefix> <name> <hash> E
+ *
+ * <prefix>	::=	_Z
+ *			__Z
+ *
+ * <name>	::= <name-segment>+
+ *
+ * <name-segment> ::= <len> <name-chars>{len}
+ *
+ * <len>	::= [1-9][0-9]+
+ *
+ * <name-chars>	::=	<[A-Za-z]> <[A-Za-z0-9]>*
+ *			<separator>
+ *			<special>
+ *
+ * <separator>	::=	'..'	# '::'
+ *
+ * <special>	::=	$SP$	# ' '
+ *			$BP$	# '*'
+ *			$RF$	# '&'
+ *			$LT$	# '<'
+ *			$GT$	# '>'
+ *			$LP$	# '('
+ *			$RP$	# ')'
+ *			$C$	# ','
+ *			$u7e$	# '~'
+ *			$u20$	# ' '
+ *			$u27$	# '\''
+ *			$u3d$	# '='
+ *			$u5b$	# '['
+ *			$u5d$	# ']'
+ *			$u7b$	# '{'
+ *			$u7d$	# '}'
+ *			$u3b$	# ';'
+ *			$u2b$	# '+'
+ *			$u22$	# '"'
+ *
+ * <hash>	:= <len> h <hex-digits>+
+ *
+ * <hex-digits>	:= <[0-9a-f]>
+ */
+
+typedef struct rustdem_state {
+	const char	*rds_str;
+	custr_t		*rds_demangled;
+	sysdem_ops_t	*rds_ops;
+	int		rds_error;
+} rustdem_state_t;
+
+static const struct rust_charmap {
+	const char	*ruc_seq;
+	char		ruc_ch;
+} rust_charmap[] = {
+	{ "$SP$", '@' },
+	{ "$BP$", '*' },
+	{ "$RF$", '&' },
+	{ "$LT$", '<' },
+	{ "$GT$", '>' },
+	{ "$LP$", '(' },
+	{ "$RP$", ')' },
+	{ "$C$", ',' },
+	{ "$u7e$", '~' },
+	{ "$u20$", ' ' },
+	{ "$u27$", '\'' },
+	{ "$u3d$", '=' },
+	{ "$u5b$", '[' },
+	{ "$u5d$", ']' },
+	{ "$u7b$", '{' },
+	{ "$u7d$", '}' },
+	{ "$u3b$", ';' },
+	{ "$u2b$", '+' },
+	{ "$u22$", '"' }
+};
+static const size_t rust_charmap_sz = ARRAY_SIZE(rust_charmap);
+
+static void *rustdem_alloc(custr_alloc_t *, size_t);
+static void rustdem_free(custr_alloc_t *, void *, size_t);
+
+static boolean_t rustdem_append_c(rustdem_state_t *, char);
+static boolean_t rustdem_all_ascii(const strview_t *);
+
+static boolean_t rustdem_parse_prefix(rustdem_state_t *, strview_t *);
+static boolean_t rustdem_parse_name(rustdem_state_t *, strview_t *);
+static boolean_t rustdem_parse_hash(rustdem_state_t *, strview_t *);
+static boolean_t rustdem_parse_num(rustdem_state_t *, strview_t *, uint64_t *);
+static boolean_t rustdem_parse_special(rustdem_state_t *, strview_t *);
+static boolean_t rustdem_add_sep(rustdem_state_t *);
+
+char *
+rust_demangle(const char *s, size_t slen, sysdem_ops_t *ops)
+{
+	rustdem_state_t st = {
+		.rds_str = s,
+		.rds_ops = ops,
+	};
+	custr_alloc_ops_t custr_ops = {
+		.custr_ao_alloc = rustdem_alloc,
+		.custr_ao_free = rustdem_free
+	};
+	custr_alloc_t custr_alloc = {
+		.cua_version = CUSTR_VERSION
+	};
+	strview_t sv;
+	int ret;
+
+	if (custr_alloc_init(&custr_alloc, &custr_ops) != 0)
+		return (NULL);
+	custr_alloc.cua_arg = &st;
+
+	sv_init_str(&sv, s, s + slen);
+
+	if (sv_remaining(&sv) < 1 || sv_peek(&sv, -1) != 'E') {
+		DEMDEBUG("ERROR: string is either too small or does not end "
+		    "with 'E'");
+		errno = EINVAL;
+		return (NULL);
+	}
+
+	if (!rustdem_parse_prefix(&st, &sv)) {
+		DEMDEBUG("ERROR: could not parse prefix");
+		errno = EINVAL;
+		return (NULL);
+	}
+	DEMDEBUG("parsed prefix; remaining='%.*s'", SV_PRINT(&sv));
+
+	if (!rustdem_all_ascii(&sv)) {
+		/* rustdem_all_ascii() provides debug output */
+		errno = EINVAL;
+		return (NULL);
+	}
+
+	if ((ret = custr_xalloc(&st.rds_demangled, &custr_alloc)) != 0)
+		return (NULL);
+
+	while (sv_remaining(&sv) > 1) {
+		if (rustdem_parse_name(&st, &sv))
+			continue;
+		if (st.rds_error != 0)
+			goto fail;
+	}
+
+	if (st.rds_error != 0 || !sv_consume_if_c(&sv, 'E'))
+		goto fail;
+
+	char *res = xstrdup(ops, custr_cstr(st.rds_demangled));
+	if (res == NULL) {
+		st.rds_error = errno;
+		goto fail;
+	}
+
+	custr_free(st.rds_demangled);
+	DEMDEBUG("result = '%s'", res);
+	return (res);
+
+fail:
+	custr_free(st.rds_demangled);
+	errno = st.rds_error;
+	return (NULL);
+}
+
+static boolean_t
+rustdem_parse_prefix(rustdem_state_t *st, strview_t *svp)
+{
+	strview_t pfx;
+
+	sv_init_sv(&pfx, svp);
+
+	DEMDEBUG("checking for '_ZN' or '__ZN' in '%.*s'", SV_PRINT(&pfx));
+
+	if (st->rds_error != 0)
+		return (B_FALSE);
+
+	if (!sv_consume_if_c(&pfx, '_'))
+		return (B_FALSE);
+
+	(void) sv_consume_if_c(&pfx, '_');
+
+	if (!sv_consume_if_c(&pfx, 'Z') || !sv_consume_if_c(&pfx, 'N'))
+		return (B_FALSE);
+
+	/* Update svp with new position */
+	sv_init_sv(svp, &pfx);
+	return (B_TRUE);
+}
+
+static boolean_t
+rustdem_parse_name_segment(rustdem_state_t *st, strview_t *svp, boolean_t first)
+{
+	strview_t sv;
+	strview_t name;
+	uint64_t len;
+	size_t rem;
+	boolean_t last = B_FALSE;
+
+	if (st->rds_error != 0 || sv_remaining(svp) == 0)
+		return (B_FALSE);
+
+	sv_init_sv(&sv, svp);
+
+	if (!rustdem_parse_num(st, &sv, &len)) {
+		DEMDEBUG("ERROR: no leading length");
+		st->rds_error = EINVAL;
+		return (B_FALSE);
+	}
+
+	rem = sv_remaining(&sv);
+
+	if (rem < len || len > SIZE_MAX) {
+		st->rds_error = EINVAL;
+		return (B_FALSE);
+	}
+
+	/* Is this the last segment before the terminating E? */
+	if (rem == len + 1) {
+		VERIFY3U(sv_peek(&sv, -1), ==, 'E');
+		last = B_TRUE;
+	}
+
+	if (!first && !rustdem_add_sep(st))
+		return (B_FALSE);
+
+	/* Reduce length of seg to the length we parsed */
+	(void) sv_init_sv_range(&name, &sv, len);
+
+	DEMDEBUG("%s: segment='%.*s'", __func__, SV_PRINT(&name));
+
+	/*
+	 * A rust hash starts with 'h', and is the last component of a name
+	 * before the terminating 'E'
+	 */
+	if (sv_peek(&name, 0) == 'h' && last) {
+		if (!rustdem_parse_hash(st, &name))
+			return (B_FALSE);
+		goto done;
+	}
+
+	while (sv_remaining(&name) > 0) {
+		switch (sv_peek(&name, 0)) {
+		case '$':
+			if (rustdem_parse_special(st, &name))
+				continue;
+			break;
+		case '_':
+			if (sv_peek(&name, 1) == '$') {
+				/*
+				 * Only consume/ignore '_'.  Leave
+				 * $ for next round.
+				 */
+				sv_consume_n(&name, 1);
+				continue;
+			}
+			break;
+		case '.':
+			/* Convert '..' to '::' */
+			if (sv_peek(&name, 1) != '.')
+				break;
+
+			if (!rustdem_add_sep(st))
+				return (B_FALSE);
+
+			sv_consume_n(&name, 2);
+			continue;
+		default:
+			break;
+		}
+
+		if (custr_appendc(st->rds_demangled,
+		    sv_consume_c(&name)) != 0) {
+			st->rds_error = ENOMEM;
+			return (B_FALSE);
+		}
+	}
+
+done:
+	DEMDEBUG("%s: consumed '%.*s'", __func__, (int)len, svp->sv_first);
+	sv_consume_n(&sv, len);
+	sv_init_sv(svp, &sv);
+	return (B_TRUE);
+}
+
+static boolean_t
+rustdem_parse_name(rustdem_state_t *st, strview_t *svp)
+{
+	strview_t name;
+	boolean_t first = B_TRUE;
+
+	if (st->rds_error != 0)
+		return (B_FALSE);
+
+	sv_init_sv(&name, svp);
+
+	if (sv_remaining(&name) == 0)
+		return (B_FALSE);
+
+	while (sv_remaining(&name) > 0 && sv_peek(&name, 0) != 'E') {
+		if (!rustdem_parse_name_segment(st, &name, first))
+			return (B_FALSE);
+		first = B_FALSE;
+	}
+
+	sv_init_sv(svp, &name);
+	return (B_TRUE);
+}
+
+static boolean_t
+rustdem_parse_hash(rustdem_state_t *st, strview_t *svp)
+{
+	strview_t sv;
+
+	sv_init_sv(&sv, svp);
+
+	VERIFY(sv_consume_if_c(&sv, 'h'));
+	if (!rustdem_append_c(st, 'h'))
+		return (B_FALSE);
+
+	while (sv_remaining(&sv) > 0) {
+		char c = sv_consume_c(&sv);
+
+		switch (c) {
+		/*
+		 * The upper-case hex digits (A-F) are excluded as valid
+		 * hash values for several reasons:
+		 *
+		 * 1. It would result in two different possible names for
+		 * the same function, leading to ambiguity in linking (among
+		 * other things).
+		 *
+		 * 2. It would cause potential ambiguity in parsing -- is a
+		 * trailing 'E' part of the hash, or the terminating character
+		 * in the mangled name?
+		 *
+		 * 3. No examples were able to be found in the wild where
+		 * uppercase digits are used, and other rust demanglers all
+		 * seem to assume the hash must contain lower-case hex digits.
+		 */
+		case '0': case '1': case '2': case '3':
+		case '4': case '5': case '6': case '7':
+		case '8': case '9': case 'a': case 'b':
+		case 'c': case 'd': case 'e': case 'f':
+			if (!rustdem_append_c(st, c))
+				return (B_FALSE);
+			break;
+		default:
+			return (B_FALSE);
+		}
+	}
+
+	sv_init_sv(svp, &sv);
+	return (B_TRUE);
+}
+
+/*
+ * A 10 digit value would imply a name 1Gb or larger in size.  It seems
+ * unlikely to the point of absurdity any such value could every possibly
+ * be valid (or even have compiled properly).  This also prevents the
+ * uint64_t conversion from possibly overflowing since the value must always
+ * be below 10 * UINT32_MAX.
+ */
+#define	MAX_DIGITS 10
+
+static boolean_t
+rustdem_parse_num(rustdem_state_t *restrict st, strview_t *restrict svp,
+    uint64_t *restrict valp)
+{
+	strview_t snum;
+	uint64_t v = 0;
+	size_t ndigits = 0;
+	char c;
+
+	if (st->rds_error != 0)
+		return (B_FALSE);
+
+	sv_init_sv(&snum, svp);
+
+	DEMDEBUG("%s: str='%.*s'", __func__, SV_PRINT(&snum));
+
+	c = sv_peek(&snum, 0);
+	if (!ISDIGIT(c)) {
+		DEMDEBUG("%s: ERROR no digits in str\n", __func__);
+		st->rds_error = EINVAL;
+		return (B_FALSE);
+	}
+
+	/*
+	 * Since there is currently no official specification on rust name
+	 * mangling, only that it has been stated that rust follows what
+	 * C++ mangling does.  In the Itanium C++ ABI (what practically
+	 * every non-Windows C++ implementation uses these days), it
+	 * explicitly disallows leading 0s in numeric values (except for
+	 * substition and template indexes, which aren't relevant here).
+	 * We enforce the same restriction -- if a rust implementation allowed
+	 * leading zeros in numbers (basically segment lengths) it'd
+	 * cause all sorts of ambiguity problems with names that likely lead
+	 * to much bigger problems with linking and such, so this seems
+	 * reasonable.
+	 */
+	if (c == '0') {
+		DEMDEBUG("%s: ERROR number starts with leading 0\n", __func__);
+		st->rds_error = EINVAL;
+		return (B_FALSE);
+	}
+
+	while (sv_remaining(&snum) > 0 && ndigits <= MAX_DIGITS) {
+		c = sv_consume_c(&snum);
+
+		if (!ISDIGIT(c))
+			break;
+
+		v *= 10;
+		v += c - '0';
+		ndigits++;
+	}
+
+	if (ndigits > MAX_DIGITS) {
+		DEMDEBUG("%s: value %llu is too large\n", __func__, v);
+		st->rds_error = ERANGE;
+		return (B_FALSE);
+	}
+
+	DEMDEBUG("%s: num=%llu", __func__, v);
+
+	*valp = v;
+	sv_consume_n(svp, ndigits);
+	return (B_TRUE);
+}
+
+static boolean_t
+rustdem_parse_special(rustdem_state_t *restrict st, strview_t *restrict svp)
+{
+	if (st->rds_error != 0)
+		return (B_FALSE);
+
+	if (sv_peek(svp, 0) != '$')
+		return (B_FALSE);
+
+	for (size_t i = 0; i < rust_charmap_sz; i++) {
+		if (sv_consume_if(svp, rust_charmap[i].ruc_seq)) {
+			if (!rustdem_append_c(st, rust_charmap[i].ruc_ch))
+				return (B_FALSE);
+			return (B_TRUE);
+		}
+	}
+	return (B_FALSE);
+}
+
+static boolean_t
+rustdem_add_sep(rustdem_state_t *st)
+{
+	if (st->rds_error != 0)
+		return (B_FALSE);
+
+	if (!rustdem_append_c(st, ':') ||
+	    !rustdem_append_c(st, ':'))
+		return (B_FALSE);
+
+	return (B_TRUE);
+}
+
+static boolean_t
+rustdem_append_c(rustdem_state_t *st, char c)
+{
+	if (st->rds_error != 0)
+		return (B_FALSE);
+
+	if (custr_appendc(st->rds_demangled, c) == 0)
+		return (B_TRUE);
+
+	st->rds_error = errno;
+	return (B_FALSE);
+}
+
+static boolean_t
+rustdem_all_ascii(const strview_t *svp)
+{
+	strview_t p;
+
+	sv_init_sv(&p, svp);
+
+	while (sv_remaining(&p) > 0) {
+		char c = sv_consume_c(&p);
+
+		/*
+		 * #including <sys/ctype.h> conflicts with <ctype.h>.  Since
+		 * we want the C locale macros (ISDIGIT, etc), it also means
+		 * we can't use isascii(3C).
+		 */
+		if ((c & 0x80) != 0) {
+			DEMDEBUG("%s: found non-ascii character 0x%02hhx at "
+			    "offset %tu", __func__, c,
+			    (ptrdiff_t)(p.sv_first - svp->sv_first));
+			return (B_FALSE);
+		}
+	}
+	return (B_TRUE);
+}
+
+static void *
+rustdem_alloc(custr_alloc_t *cao, size_t len)
+{
+	rustdem_state_t *st = cao->cua_arg;
+	return (zalloc(st->rds_ops, len));
+}
+
+static void
+rustdem_free(custr_alloc_t *cao, void *p, size_t len)
+{
+	rustdem_state_t *st = cao->cua_arg;
+	xfree(st->rds_ops, p, len);
+}
diff --git a/usr/src/lib/libdemangle/common/strview.c b/usr/src/lib/libdemangle/common/strview.c
new file mode 100644
index 0000000000..e4576ee17a
--- /dev/null
+++ b/usr/src/lib/libdemangle/common/strview.c
@@ -0,0 +1,107 @@
+/*
+ * 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 2019, Joyent, Inc.
+ */
+
+#include <string.h>
+#include <sys/debug.h>
+#include "strview.h"
+
+void
+sv_init_sv(strview_t *sv, const strview_t *src)
+{
+	*sv = *src;
+}
+
+void
+sv_init_sv_range(strview_t *sv, const strview_t *src, size_t len)
+{
+	VERIFY3U(sv_remaining(src), >=, len);
+
+	sv->sv_first = src->sv_first;
+	sv->sv_last = src->sv_first + len;
+	sv->sv_rem = len;
+}
+
+void
+sv_init_str(strview_t *sv, const char *first, const char *last)
+{
+	if (last == NULL)
+		last = first + strlen(first);
+
+	VERIFY3P(first, <=, last);
+	sv->sv_first = first;
+	sv->sv_last = last;
+	sv->sv_rem = (size_t)(uintptr_t)(sv->sv_last - sv->sv_first);
+}
+
+size_t
+sv_remaining(const strview_t *sv)
+{
+	return (sv->sv_rem);
+}
+
+boolean_t
+sv_consume_if_c(strview_t *sv, char c)
+{
+	if (sv->sv_rem < 1 || *sv->sv_first != c)
+		return (B_FALSE);
+
+	sv->sv_first++;
+	sv->sv_rem--;
+	return (B_TRUE);
+}
+
+boolean_t
+sv_consume_if(strview_t *sv, const char *str)
+{
+	size_t slen = strlen(str);
+
+	if (sv->sv_rem < slen)
+		return (B_FALSE);
+	if (strncmp(sv->sv_first, str, slen) != 0)
+		return (B_FALSE);
+
+	sv->sv_first += slen;
+	sv->sv_rem -= slen;
+	return (B_TRUE);
+}
+
+char
+sv_peek(const strview_t *sv, ssize_t n)
+{
+	const char *p;
+
+	p = (n >= 0) ? sv->sv_first + n : sv->sv_last + n;
+	return ((p >= sv->sv_first && p < sv->sv_last) ? *p : '\0');
+}
+
+char
+sv_consume_c(strview_t *sv)
+{
+	char c = '\0';
+
+	if (sv->sv_first < sv->sv_last) {
+		c = *sv->sv_first++;
+		sv->sv_rem--;
+	}
+	return (c);
+}
+
+void
+sv_consume_n(strview_t *sv, size_t n)
+{
+	VERIFY3U(sv->sv_rem, >=, n);
+	sv->sv_first += n;
+	sv->sv_rem -= n;
+}
diff --git a/usr/src/lib/libdemangle/common/strview.h b/usr/src/lib/libdemangle/common/strview.h
new file mode 100644
index 0000000000..ac94c67c6c
--- /dev/null
+++ b/usr/src/lib/libdemangle/common/strview.h
@@ -0,0 +1,140 @@
+/*
+ * 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 2019, Joyent, Inc.
+ */
+
+#ifndef _STRVIEW_H
+#define	_STRVIEW_H
+
+#include <inttypes.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * strview_t's represent a read-only subset of a string.  It is somewhat
+ * similar to the concept of ranges found in other languages in that one can
+ * create a strview_t, and then create a smaller range for iteration.
+ *
+ * sv_first is the address of the first location (and is advanced as values
+ * are consumed) in the string.
+ *
+ * sv_last is the address one byte after the last valid value of the subset.
+ * Basically, the length of the range is equal to 'sv_last - sv_first'.  For
+ * example, in the string 'abcdef' to create a view 'bcd', *sv_first would
+ * equal 'b' and *sv_last would equal 'e'.
+ *
+ * sv_rem is the number of bytes remaining in the range.
+ *
+ * A strview_t maintains references to the underlying string, so the lifetime
+ * of a strview_t should be equal to or less than the underlying string (i.e.
+ * it doesn't copy the data from the underlying string, but maintains pointers
+ * to the original data).
+ *
+ * While the underlying string does not need to be NUL-terminated, NUL is still
+ * used as a sentinel value in some instances (e.g. sv_peek()), and should not
+ * be contained within the defined range.
+ *
+ * As hinted above, the functions currently do not deal with multi-byte
+ * characters, i.e. each character is assumed to be a single byte.  The
+ * current consumers do not need to handle multi-byte characters (UTF-8
+ * or otherwise), so this is sufficient at the current time.
+ */
+typedef struct strview {
+	const char *sv_first;
+	const char *sv_last;
+	size_t sv_rem;
+} strview_t;
+
+/*
+ * SV_PRINT() is used for printing strview_t values during debugging, e.g.
+ * `DEMDEBUG("%*.s", SV_PRINT(sv));`
+ */
+#define	SV_PRINT(_sv)	(int)(_sv)->sv_rem, (_sv)->sv_first
+
+/*
+ * Initialize a strview_t from an already initialized strview_t -- the state of
+ * the source strview_t is duplicated in the newly initialized strview_t.
+ */
+void sv_init_sv(strview_t *, const strview_t *);
+
+/*
+ * Initialize a strview_t as a subset of an already initialized strview_t.
+ * The size of the subset (size_t) must be <= sv_remaining(src).
+ */
+void sv_init_sv_range(strview_t *, const strview_t *, size_t);
+
+/*
+ * Initialize a strview_t from a string.  The two const char * pointers are the
+ * sv_first and sv_last values to use (see above).  If the source string is
+ * NUL-terminated, one can optionally pass NULL for the second parameter in
+ * which case, the entire NUL-terminated string (starting at sv_first) is
+ * treated as a strview_t.
+ */
+void sv_init_str(strview_t *, const char *, const char *);
+
+/*
+ * Return the number of bytes remaining to consume in the strview_t
+ */
+size_t sv_remaining(const strview_t *);
+
+/*
+ * Return the char at the given position in the strview_t (without advancing
+ * the position).  Position values >=0 are relative to the current position
+ * of the strview_t (e.g. '0' will return the next character, '1' will return
+ * the character after that), while negative position values are relative to
+ * the end of the strview_t (e.g. '-1' will return the last character, '-2'
+ * will return the second to last character).
+ *
+ * If the position value is out of range, '\0' is returned.
+ */
+char sv_peek(const strview_t *, ssize_t);
+
+/*
+ * Return the next character and advance the strview_t position.  If no more
+ * characters are available, '\0' is returned.
+ */
+char sv_consume_c(strview_t *);
+
+/*
+ * Advance the position of the strview_t by the given number of bytes.  The
+ * amount must be <= the number of bytes remaining in the strview_t.
+ */
+void sv_consume_n(strview_t *, size_t);
+
+/*
+ * Advance the strview_t position if the bytes of the strview starting at the
+ * current position match the given NUL-terminated string.  The length of the
+ * NUL-terminated string must be <= the number of bytes remaining in the
+ * strview_t.
+ *
+ * If there is a match, the position of the strview_t is advanced by the
+ * length of the NUL-terminated comparison string, and B_TRUE is returned. If
+ * there is no match, the position is not advanced and B_FALSE is returned.
+ */
+boolean_t sv_consume_if(strview_t *, const char *);
+
+/*
+ * Advance the position of the strview_t if the next char in the strview_t
+ * is equal to the given char.  If there is a match, the strview_t position
+ * is advanced one byte and B_TRUE is returned.  If they do not match, B_FALSE
+ * is returned and the position is not advanced.
+ */
+boolean_t sv_consume_if_c(strview_t *, char);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _STRVIEW_H */
diff --git a/usr/src/lib/libdemangle/common/util.c b/usr/src/lib/libdemangle/common/util.c
index 9ffb72c79b..739c554826 100644
--- a/usr/src/lib/libdemangle/common/util.c
+++ b/usr/src/lib/libdemangle/common/util.c
@@ -11,6 +11,7 @@
 
 /*
  * Copyright 2017 Jason King
+ * Copyright 2019, Joyent, Inc.
  */
 
 #include <sys/debug.h>
@@ -71,6 +72,20 @@ xrealloc(sysdem_ops_t *ops, void *p, size_t oldsz, size_t newsz)
 	return (temp);
 }
 
+char *
+xstrdup(sysdem_ops_t *ops, const char *src)
+{
+	size_t len = strlen(src);
+	char *str = zalloc(ops, len + 1);
+
+	if (str == NULL)
+		return (NULL);
+
+	/* zalloc(len+1) guarantees this will be NUL-terminated */
+	(void) memcpy(str, src, len);
+	return (str);
+}
+
 /*ARGSUSED*/
 static void
 def_free(void *p, size_t len)
diff --git a/usr/src/man/man1/dis.1 b/usr/src/man/man1/dis.1
index bff3a55372..103fd48509 100644
--- a/usr/src/man/man1/dis.1
+++ b/usr/src/man/man1/dis.1
@@ -43,8 +43,9 @@
 .\" Copyright 1989 AT&T
 .\" Portions Copyright (c) 1992, X/Open Company Limited  All Rights Reserved
 .\" Copyright (c) 2009, Sun Microsystems, Inc.  All Rights Reserved
+.\" Copyright 2019 Joyent, Inc.
 .\"
-.TH DIS 1 "Aug 24, 2009"
+.TH DIS 1 "Dec 19, 2018"
 .SH NAME
 dis \- object code disassembler
 .SH SYNOPSIS
@@ -55,14 +56,12 @@ dis \- object code disassembler
 .fi
 
 .SH DESCRIPTION
-.sp
 .LP
 The \fBdis\fR command produces an assembly language listing of \fIfile\fR,
 which can be an object file or an archive of object files. The listing includes
 assembly statements and an octal or hexadecimal representation of the binary
 that produced those statements.
 .SH OPTIONS
-.sp
 .LP
 Options are interpreted by the disassembler and can be specified in any order.
 .sp
@@ -74,7 +73,7 @@ The following options are supported:
 \fB\fB-C\fR\fR
 .ad
 .RS 15n
-Displays demangled C++ symbol names in the disassembly.
+Displays demangled symbol names in the disassembly.
 .RE
 
 .sp
@@ -194,7 +193,6 @@ On output, a number enclosed in brackets at the beginning of a line, such as
 following instruction. These line numbers is printed only if the file was
 compiled with additional debugging information.
 .SH OPERANDS
-.sp
 .LP
 The following operand is supported:
 .sp
@@ -207,7 +205,6 @@ A path name of an object file or an archive (see \fBar\fR(1)) of object files.
 .RE
 
 .SH ENVIRONMENT VARIABLES
-.sp
 .LP
 See \fBenviron\fR(5) for descriptions of the following environment variables
 that affect the execution of \fBdis\fR: \fBLC_CTYPE\fR, \fBLC_MESSAGES\fR, and
@@ -224,7 +221,6 @@ defaults to searching for the library under \fB/usr/lib\fR.
 .RE
 
 .SH EXIT STATUS
-.sp
 .LP
 The following exit values are returned:
 .sp
@@ -246,7 +242,6 @@ An error occurred.
 .RE
 
 .SH FILES
-.sp
 .ne 2
 .na
 \fB\fB/usr/lib\fR\fR
@@ -256,7 +251,6 @@ default \fBLIBDIR\fR
 .RE
 
 .SH ATTRIBUTES
-.sp
 .LP
 See \fBattributes\fR(5) for descriptions of the following attributes:
 .sp
@@ -276,12 +270,10 @@ Interface Stability	See below.
 The human readable output is Uncommitted. The command line options are
 Committed.
 .SH SEE ALSO
-.sp
 .LP
 \fBar\fR(1), \fBas\fR(1), \fBld\fR(1), \fBa.out\fR(4), \fBattributes\fR(5),
 \fBenviron\fR(5)
 .SH DIAGNOSTICS
-.sp
 .LP
 The self-explanatory diagnostics indicate errors in the command line or
 problems encountered with the specified files.
diff --git a/usr/src/man/man1/dump.1 b/usr/src/man/man1/dump.1
index 50540b462d..6c1c4ff317 100644
--- a/usr/src/man/man1/dump.1
+++ b/usr/src/man/man1/dump.1
@@ -1,9 +1,10 @@
 '\" te
 .\"  Copyright 1989 AT&T  Copyright (c) 2002, Sun Microsystems, Inc.  All Rights Reserved
+.\" Copyright 2019 Joyent, Inc.
 .\" 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]
-.TH DUMP 1 "Sep 6, 2002"
+.TH DUMP 1 "Dec 19, 2018"
 .SH NAME
 dump \- dump selected parts of an object file
 .SH SYNOPSIS
@@ -28,7 +29,6 @@ dump \- dump selected parts of an object file
 .fi
 
 .SH DESCRIPTION
-.sp
 .LP
 The \fBdump\fR utility dumps selected parts of each of its object \fIfile\fR
 arguments.
@@ -37,7 +37,6 @@ arguments.
 The \fBdump\fR utility is best suited for use in shell scripts, whereas the
 \fBelfdump\fR(1) command is recommended for more human-readable output.
 .SH OPTIONS
-.sp
 .LP
 This utility will accept both object files and archives of object files. It
 processes each file argument according to one or more of the following options:
@@ -65,7 +64,7 @@ Dumps the string table(s).
 \fB\fB-C\fR\fR
 .ad
 .RS 20n
-Dumps decoded C++ symbol table names.
+Dumps decoded symbol table names.
 .RE
 
 .sp
@@ -315,7 +314,6 @@ The \fBdump\fR utility attempts to format the information it dumps in a
 meaningful way, printing certain information in character, hexadecimal, octal,
 or decimal representation as appropriate.
 .SH SEE ALSO
-.sp
 .LP
 \fBelfdump\fR(1), \fBnm\fR(1), \fBar.h\fR(3HEAD), \fBa.out\fR(4),
 \fBattributes\fR(5)
diff --git a/usr/src/man/man1/elfdump.1 b/usr/src/man/man1/elfdump.1
index c27e7aef0b..3859847ecf 100644
--- a/usr/src/man/man1/elfdump.1
+++ b/usr/src/man/man1/elfdump.1
@@ -1,6 +1,7 @@
 '\" te
 .\"  Copyright (c) 2009 by Sun Microsystems, Inc.
 .\" All rights reserved.
+.\" Copyright 2019 Joyent, Inc.
 .\" 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
@@ -11,7 +12,7 @@
 .\"  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]
-.TH ELFDUMP 1 "Apr 3, 2009"
+.TH ELFDUMP 1 "Dec 19, 2018"
 .SH NAME
 elfdump \- dumps selected parts of an object file
 .SH SYNOPSIS
@@ -22,7 +23,6 @@ elfdump \- dumps selected parts of an object file
 .fi
 
 .SH DESCRIPTION
-.sp
 .LP
 The \fBelfdump\fR utility symbolically dumps selected parts of the specified
 object file(s). The options allow specific portions of the file to be
@@ -93,7 +93,6 @@ displays all available information for each object.
 For a complete description of the displayed information, refer to the \fILinker
 and Libraries Guide\fR.
 .SH OPTIONS
-.sp
 .LP
 The following options are supported:
 .sp
@@ -111,7 +110,7 @@ Dumps section header information.
 \fB\fB-C\fR\fR
 .ad
 .RS 18n
-Demangles C++ symbol names.
+Demangles symbol names.
 .RE
 
 .sp
@@ -505,7 +504,6 @@ Dumps the contents of the \fB\&.SUNW_syminfo\fR section.
 .RE
 
 .SH OPERANDS
-.sp
 .LP
 The following operand is supported:
 .sp
@@ -519,7 +517,6 @@ The name of the specified object file.
 
 .SH USAGE
 .SS "Matching Options"
-.sp
 .LP
 The options \fB-I\fR, \fB-N\fR, and \fB-T\fR are collectively referred to as
 the \fBmatching options\fR. These options are used to narrow the range of
@@ -562,7 +559,6 @@ matched by any of the matching options used. This feature allows for the
 selection of complex groupings of items using the most convenient form for
 specifying each item.
 .SH FILES
-.sp
 .ne 2
 .na
 \fB\fBliblddbg.so\fR\fR
@@ -572,7 +568,6 @@ linker debugging library
 .RE
 
 .SH ATTRIBUTES
-.sp
 .LP
 See \fBattributes\fR(5) for descriptions of the following attributes:
 .sp
@@ -588,7 +583,6 @@ Interface Stability	Committed
 .TE
 
 .SH SEE ALSO
-.sp
 .LP
 \fBar\fR(1), \fBdump\fR(1), \fBnm\fR(1), \fBpvs\fR(1), \fBelf\fR(3ELF),
 \fBcore\fR(4), \fBattributes\fR(5)
diff --git a/usr/src/man/man1/gprof.1 b/usr/src/man/man1/gprof.1
index 4e2d0bf807..feb128771c 100644
--- a/usr/src/man/man1/gprof.1
+++ b/usr/src/man/man1/gprof.1
@@ -1,9 +1,10 @@
 '\" te
 .\"  Copyright 1989 AT&T  Copyright (c) 2007, Sun Microsystems, Inc.  All Rights Reserved
+.\" Copyright 2019 Joyent, Inc.
 .\" 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]
-.TH GPROF 1 "Feb 8, 2007"
+.TH GPROF 1 "Dec 19, 2018"
 .SH NAME
 gprof \- display call-graph profile data
 .SH SYNOPSIS
@@ -16,7 +17,6 @@ gprof \- display call-graph profile data
 .fi
 
 .SH DESCRIPTION
-.sp
 .LP
 The \fBgprof\fR utility produces an execution profile of a program. The effect
 of called routines is incorporated in the profile of each caller.  The profile
@@ -67,7 +67,6 @@ number of times that arc is traversed.
 The profiled program must call \fBexit\fR(2) or return normally for the
 profiling information to be saved in the \fBgmon.out\fR file.
 .SH OPTIONS
-.sp
 .LP
 The following options are supported:
 .sp
@@ -109,7 +108,7 @@ shared objects' text segments are not examined.
 \fB\fB-C\fR\fR
 .ad
 .RS 19n
-Demangle C++ symbol names before printing them out.
+Demangle symbol names before printing them out.
 .RE
 
 .sp
@@ -230,7 +229,6 @@ examined by the \fB-c\fR option.
 .RE
 
 .SH ENVIRONMENT VARIABLES
-.sp
 .ne 2
 .na
 \fB\fBPROFDIR\fR\fR
@@ -246,7 +244,6 @@ file \fBgmon.out\fR.
 .RE
 
 .SH FILES
-.sp
 .ne 2
 .na
 \fB\fBa.out\fR\fR
@@ -283,7 +280,6 @@ summarized dynamic call-graph and profile
 .RE
 
 .SH SEE ALSO
-.sp
 .LP
 \fBcc\fR(1), \fBld.so.1\fR(1), \fBprof\fR(1), \fBexit\fR(2), \fBpcsample\fR(2),
 \fBprofil\fR(2), \fBmalloc\fR(3C), \fBmalloc\fR(3MALLOC), \fBmonitor\fR(3C),
@@ -297,7 +293,6 @@ Profiler Proceedings of the SIGPLAN '82 Symposium on Compiler Construction\fR,
 .LP
 \fILinker and Libraries Guide\fR
 .SH NOTES
-.sp
 .LP
 If the executable image has been stripped and does not have the \fB\&.symtab\fR
 symbol table, \fBgprof\fR reads the global dynamic symbol tables
@@ -339,7 +334,6 @@ functions are not present in an unprofiled application, time accumulated and
 call counts for these functions may be ignored when evaluating the performance
 of an application.
 .SS "64-bit profiling"
-.sp
 .LP
 64-bit profiling may be used freely with dynamically linked executables, and
 profiling information is collected for the shared objects if the objects are
@@ -353,7 +347,6 @@ appropriate module for the symbol.
 When using the \fB-s\fR or \fB-D\fRoption to sum multiple profile files, care
 must be taken not to mix 32-bit profile files with 64-bit profile files.
 .SS "32-bit profiling"
-.sp
 .LP
 32-bit profiling may be used with dynamically linked executables, but care must
 be applied. In 32-bit profiling, shared objects cannot be profiled with
@@ -386,7 +379,6 @@ improvement can be made by looking at routine \fBB\fR and not routine \fBA\fR.
 The value of the profiler in this case is severely degraded; the solution is to
 use archives as much as possible for profiling.
 .SH BUGS
-.sp
 .LP
 Parents which are not themselves profiled will have the time of their profiled
 children propagated to them, but they will appear to be spontaneously invoked
diff --git a/usr/src/man/man1/nm.1 b/usr/src/man/man1/nm.1
index eba513cc07..8e6b82a346 100644
--- a/usr/src/man/man1/nm.1
+++ b/usr/src/man/man1/nm.1
@@ -45,7 +45,7 @@
 .\" Copyright (c) 2007, Sun Microsystems, Inc.  All Rights Reserved
 .\" Copyright 2019, Joyent, Inc.
 .\"
-.TH NM 1 "March 7, 2019"
+.TH NM 1 "March 26, 2019"
 .SH NAME
 nm \- print name list of an object file
 .SH SYNOPSIS
@@ -87,7 +87,7 @@ Writes the full path name or library name of an object on each line.
 \fB\fB-C\fR\fR
 .ad
 .RS 13n
-Demangles C++ symbol names before printing them out.
+Demangles symbol names before printing them out.
 .RE
 
 .sp
diff --git a/usr/src/man/man1/pvs.1 b/usr/src/man/man1/pvs.1
index 8304261cd3..b6ea0d52d8 100644
--- a/usr/src/man/man1/pvs.1
+++ b/usr/src/man/man1/pvs.1
@@ -1,10 +1,11 @@
 '\" te
 .\"  Copyright (c) 2008, Sun Microsystems, Inc.
+.\" Copyright 2019 Joyent, Inc.
 .\"  All Rights Reserved
 .\" 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]
-.TH PVS 1 "Sep 25, 2008"
+.TH PVS 1 "Dec 19, 2018"
 .SH NAME
 pvs \- display the internal version information of dynamic objects
 .SH SYNOPSIS
@@ -14,7 +15,6 @@ pvs \- display the internal version information of dynamic objects
 .fi
 
 .SH DESCRIPTION
-.sp
 .LP
 The \fBpvs\fR utility displays any internal version information contained
 within an \fBELF\fR file. Commonly, these files are dynamic executables and
@@ -53,7 +53,6 @@ dynamic object being created. At process initialization, the runtime linker
 uses any version \fIdependencies\fR as a means of validating the interface
 requirements of the dynamic objects used to construct the process.
 .SH OPTIONS
-.sp
 .LP
 The following options are supported. If neither the \fB-d\fR or \fB-r\fR
 options are specified, both are enabled.
@@ -63,7 +62,7 @@ options are specified, both are enabled.
 \fB\fB-C\fR\fR
 .ad
 .RS 18n
-Demangles C++ symbol names.
+Demangles symbol names.
 .RE
 
 .sp
@@ -220,7 +219,6 @@ inheritance of the base version definition is also shown. When used with the
 .RE
 
 .SH OPERANDS
-.sp
 .LP
 The following operands are supported.
 .sp
@@ -234,7 +232,6 @@ The  \fBELF\fR file about which internal version information is displayed.
 
 .SH USAGE
 .SS "Matching Options"
-.sp
 .LP
 The \fB-I\fR and \fB-N\fR options are collectively referred to as the
 \fBmatching options\fR. These options are used to narrow the range of versions
@@ -388,7 +385,6 @@ specify its name:
 .sp
 
 .SH EXIT STATUS
-.sp
 .LP
 If the requested version information is not found, a non-zero value is
 returned. Otherwise, a \fB0\fR value is returned.
@@ -415,7 +411,6 @@ neither the \fB-d\fR nor \fB-r\fR option is specified and no version
 definitions or version requirements are found.
 .RE
 .SH SEE ALSO
-.sp
 .LP
 \fBelfdump\fR(1), \fBld\fR(1), \fBldd\fR(1), \fBstrip\fR(1), \fBelf\fR(3ELF),
 \fBattributes\fR(5)
diff --git a/usr/src/pkg/manifests/system-test-utiltest.mf b/usr/src/pkg/manifests/system-test-utiltest.mf
index df9546a962..6533f742c5 100644
--- a/usr/src/pkg/manifests/system-test-utiltest.mf
+++ b/usr/src/pkg/manifests/system-test-utiltest.mf
@@ -15,6 +15,7 @@
 # Copyright 2014 Nexenta Systems, Inc. All rights reserved.
 # Copyright 2019, Joyent, Inc.
 # Copyright 2017 Jason King.
+# Copyright 2018, Joyent, Inc.
 #
 
 set name=pkg.fmri value=pkg:/system/test/utiltest@$(PKGVERS)
@@ -115,6 +116,7 @@ file path=opt/util-tests/tests/date_test mode=0555
 file path=opt/util-tests/tests/demangle/afl-fast mode=0555
 file path=opt/util-tests/tests/demangle/gcc-libstdc++ mode=0555
 file path=opt/util-tests/tests/demangle/llvm-stdcxxabi mode=0555
+file path=opt/util-tests/tests/demangle/rust mode=0555
 file path=opt/util-tests/tests/dis/distest mode=0555
 file path=opt/util-tests/tests/dis/i386/32.adx.out mode=0444
 file path=opt/util-tests/tests/dis/i386/32.adx.s mode=0444
@@ -425,5 +427,7 @@ file path=opt/util-tests/tests/xargs_test mode=0555
 license lic_CDDL license=lic_CDDL
 license usr/src/lib/libdemangle/THIRDPARTYLICENSE \
     license=usr/src/lib/libdemangle/THIRDPARTYLICENSE
+license usr/src/test/util-tests/tests/demangle/THIRDPARTYLICENSE.rust \
+    license=usr/src/test/util-tests/tests/demangle/THIRDPARTYLICENSE.rust
 depend fmri=system/library/iconv/utf-8 type=require
 depend fmri=system/test/testrunner type=require
diff --git a/usr/src/test/util-tests/tests/demangle/Makefile b/usr/src/test/util-tests/tests/demangle/Makefile
index fd64f0a2f4..18c2a25cb9 100644
--- a/usr/src/test/util-tests/tests/demangle/Makefile
+++ b/usr/src/test/util-tests/tests/demangle/Makefile
@@ -11,6 +11,7 @@
 
 #
 # Copyright 2018 Jason King.
+# Copyright 2019 Joyent, Inc.
 #
 
 include $(SRC)/Makefile.master
@@ -19,7 +20,7 @@ include $(SRC)/test/Makefile.com
 
 ROOTBINDIR = $(ROOTOPTPKG)/bin
 
-PROG = gcc-libstdc++ llvm-stdcxxabi afl-fast
+PROG = gcc-libstdc++ llvm-stdcxxabi afl-fast rust
 
 ROOTOPTPKG = $(ROOT)/opt/util-tests
 TESTDIR = $(ROOTOPTPKG)/tests/demangle
@@ -33,6 +34,7 @@ SRCS = $(OBJS:%.o=%.c)
 CSTD = $(CSTD_GNU99)
 
 LDLIBS += -ldemangle-sys
+rust := LDLIBS += -lumem
 
 all: $(PROG)
 
@@ -48,6 +50,10 @@ afl-fast: afl-fast.o
 	$(LINK.c) -o $@ afl-fast.o $(LDLIBS)
 	$(POST_PROCESS)
 
+rust: rust.o
+	$(LINK.c) -o $@ rust.o $(LDLIBS)
+	$(POST_PROCESS)
+
 install: all $(CMDS)
 
 lint:
diff --git a/usr/src/test/util-tests/tests/demangle/THIRDPARTYLICENSE.rust b/usr/src/test/util-tests/tests/demangle/THIRDPARTYLICENSE.rust
new file mode 100644
index 0000000000..39e0ed6602
--- /dev/null
+++ b/usr/src/test/util-tests/tests/demangle/THIRDPARTYLICENSE.rust
@@ -0,0 +1,25 @@
+Copyright (c) 2014 Alex Crichton
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/usr/src/test/util-tests/tests/demangle/THIRDPARTYLICENSE.rust.descrip b/usr/src/test/util-tests/tests/demangle/THIRDPARTYLICENSE.rust.descrip
new file mode 100644
index 0000000000..8b510416f8
--- /dev/null
+++ b/usr/src/test/util-tests/tests/demangle/THIRDPARTYLICENSE.rust.descrip
@@ -0,0 +1 @@
+Rust test case data
diff --git a/usr/src/test/util-tests/tests/demangle/rust.c b/usr/src/test/util-tests/tests/demangle/rust.c
new file mode 100644
index 0000000000..0b13c9db7e
--- /dev/null
+++ b/usr/src/test/util-tests/tests/demangle/rust.c
@@ -0,0 +1,214 @@
+/*
+ * Copyright (c) 2014 Alex Crichton
+ *
+ * Permission is hereby granted, free of charge, to any
+ * person obtaining a copy of this software and associated
+ * documentation files (the "Software"), to deal in the
+ * Software without restriction, including without
+ * limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software
+ * is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice
+ * shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ * ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+ * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+ * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+ * SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+ * IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+/*
+ * Copyright 2019, Joyent, Inc.
+ */
+
+/*
+ * Test cases taken from rustc-demangle 0.1.9
+ */
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/sysmacros.h>
+#include <demangle-sys.h>
+
+typedef struct rust_test_case {
+	const char *mangled;
+	const char *demangled;
+} rust_test_case_t;
+#define	T(_m, _d) { .mangled = _m, .demangled = _d }
+#define	T_ERR(_m) { .mangled = _m }
+
+typedef struct rust_test_grp {
+	const char		*name;
+	rust_test_case_t	tests[];
+} rust_test_grp_t;
+#define	GROUP(_n, ...)			\
+	static rust_test_grp_t _n = {	\
+		.name = #_n,		\
+		.tests = {		\
+			__VA_ARGS__,	\
+			{ NULL, NULL }	\
+		}			\
+	}
+
+GROUP(demangle,
+    T_ERR("test"),
+    T("_ZN4testE", "test"),
+    T_ERR("_ZN4test"),
+    T("_ZN4test1a2bcE", "test::a::bc"));
+
+GROUP(demangle_dollars,
+    T("_ZN4$RP$E", ")"),
+    T("_ZN8$RF$testE", "&test"),
+    T("_ZN8$BP$test4foobE", "*test::foob"),
+    T("_ZN9$u20$test4foobE", " test::foob"),
+    T("_ZN35Bar$LT$$u5b$u32$u3b$$u20$4$u5d$$GT$E", "Bar<[u32; 4]>"));
+
+GROUP(demangle_many_dollars,
+    T("_ZN13test$u20$test4foobE", "test test::foob"),
+    T("_ZN12test$BP$test4foobE", "test*test::foob"));
+
+/* BEGIN CSTYLED */
+GROUP(demangle_osx,
+    T("__ZN5alloc9allocator6Layout9for_value17h02a996811f781011E",
+    "alloc::allocator::Layout::for_value::h02a996811f781011"),
+    T("__ZN38_$LT$core..option..Option$LT$T$GT$$GT$6unwrap18_MSG_FILE_LINE_COL17haf7cb8d5824ee659E",
+    "<core::option::Option<T>>::unwrap::_MSG_FILE_LINE_COL::haf7cb8d5824ee659"),
+    T("__ZN4core5slice89_$LT$impl$u20$core..iter..traits..IntoIterator$u20$for$u20$$RF$$u27$a$u20$$u5b$T$u5d$$GT$9into_iter17h450e234d27262170E",
+    "core::slice::<impl core::iter::traits::IntoIterator for &'a [T]>::into_iter::h450e234d27262170"));
+/* END CSTYLED */
+
+GROUP(demangle_elements_beginning_with_underscore,
+    T("_ZN13_$LT$test$GT$E", "<test>"),
+    T("_ZN28_$u7b$$u7b$closure$u7d$$u7d$E", "{{closure}}"),
+    T("_ZN15__STATIC_FMTSTRE", "__STATIC_FMTSTR"));
+
+/* BEGIN CSTYLED */
+GROUP(demangle_trait_impls,
+    T("_ZN71_$LT$Test$u20$$u2b$$u20$$u27$static$u20$as$u20$foo..Bar$LT$Test$GT$$GT$3barE",
+    "<Test + 'static as foo::Bar<Test>>::bar"));
+/* END CSTYLED */
+
+GROUP(invalid_no_chop, T_ERR("_ZNfooE"));
+
+/* BEGIN CSTYLED */
+GROUP(handle_assoc_types,
+    T("_ZN151_$LT$alloc..boxed..Box$LT$alloc..boxed..FnBox$LT$A$C$$u20$Output$u3d$R$GT$$u20$$u2b$$u20$$u27$a$GT$$u20$as$u20$core..ops..function..FnOnce$LT$A$GT$$GT$9call_once17h69e8f44b3723e1caE",
+    "<alloc::boxed::Box<alloc::boxed::FnBox<A, Output=R> + 'a> as core::ops::function::FnOnce<A>>::call_once::h69e8f44b3723e1ca"));
+/* END CSTYLED */
+
+static rust_test_grp_t *rust_tests[] = {
+	&demangle,
+	&demangle_dollars,
+	&demangle_many_dollars,
+	&demangle_osx,
+	&demangle_elements_beginning_with_underscore,
+	&demangle_trait_impls,
+	&invalid_no_chop,
+	&handle_assoc_types
+};
+
+static const size_t n_rust_tests = ARRAY_SIZE(rust_tests);
+
+static boolean_t
+check_failure(size_t i, rust_test_case_t *tc, const char *dem, boolean_t res)
+{
+	int savederr = errno;
+
+	if (dem == NULL && savederr == EINVAL)
+		return (B_TRUE);
+
+	if (res)
+		(void) printf("FAILURE\n");
+
+	if (dem != NULL) {
+		(void) printf("  [%zu] Successfully demanged an invalid "
+		    "name\n", i);
+		(void) printf("         Name: '%s'\n", tc->mangled);
+		(void) printf("    Demangled: '%s'\n", dem);
+		return (B_FALSE);
+	}
+
+	(void) printf("  [%zu] demangle() returned an unexpected error\n", i);
+	(void) printf("    Errno: %d\n", savederr);
+	return (B_FALSE);
+}
+
+static boolean_t
+check_success(size_t i, rust_test_case_t *tc, const char *dem, boolean_t res)
+{
+	if (dem != NULL && strcmp(tc->demangled, dem) == 0)
+		return (B_TRUE);
+
+	if (res)
+		(void) printf("FAILURE\n");
+
+	if (dem == NULL) {
+		(void) printf("  [%zu] Failed to demangle '%s'\n", i,
+		    tc->mangled);
+		return (B_FALSE);
+	}
+
+	(void) printf("  [%zu] Demangled results do not match.\n", i);
+	(void) printf("       Mangled: %s\n", tc->mangled);
+	(void) printf("      Expected: %s\n", tc->demangled);
+	(void) printf("        Actual: %s\n", dem);
+	return (B_FALSE);
+}
+
+static boolean_t
+run_test(rust_test_grp_t *test)
+{
+	boolean_t res = B_TRUE;
+
+	(void) printf("Test %s: ", test->name);
+
+	for (size_t i = 0; test->tests[i].mangled != NULL; i++) {
+		char *dem;
+
+		dem = sysdemangle(test->tests[i].mangled, SYSDEM_LANG_RUST,
+		    NULL);
+		if (test->tests[i].demangled == NULL)
+			res &= check_failure(i, &test->tests[i], dem, res);
+		else
+			res &= check_success(i, &test->tests[i], dem, res);
+
+		free(dem);
+	}
+
+	if (res)
+		(void) printf("SUCCESS\n");
+
+	return (res);
+}
+
+int
+main(int argc, char **argv)
+{
+	boolean_t ok = B_TRUE;
+
+	for (size_t i = 0; i < n_rust_tests; i++)
+		ok &= run_test(rust_tests[i]);
+
+	return (ok ? 0 : 1);
+}
+
+const char *
+_umem_debug_init(void)
+{
+	return ("default,verbose");
+}
+
+const char *
+_umem_logging_init(void)
+{
+	return ("fail,contents");
+}