* sanitizer_common/sanitizer_symbolizer_libbacktrace.h

	(LibbacktraceSymbolizer::Demangle): New declaration.
	* sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
	(POSIXSymbolizer::Demangle): Use libbacktrace_symbolizer_'s Demangle
	method if possible.
	* sanitizer_common/sanitizer_symbolizer_libbacktrace.cc: Include
	"demangle.h" if SANITIZE_CP_DEMANGLE is defined.
	(struct CplusV3DemangleData): New type.
	(CplusV3DemangleCallback, CplusV3Demangle): New functions.
	(SymbolizeCodePCInfoCallback, SymbolizeCodeCallback,
	SymbolizeDataCallback): Use CplusV3Demangle.
	* sanitizer_common/Makefile.am (AM_CXXFLAGS): Add
	-DSANITIZE_CP_DEMANGLE and -I $(top_srcdir)/../include.
	* libbacktrace/backtrace-rename.h (cplus_demangle_builtin_types,
	cplus_demangle_fill_ctor, cplus_demangle_fill_dtor,
	cplus_demangle_fill_extended_operator, cplus_demangle_fill_name,
	cplus_demangle_init_info, cplus_demangle_mangled_name,
	cplus_demangle_operators, cplus_demangle_print,
	cplus_demangle_print_callback, cplus_demangle_type, cplus_demangle_v3,
	cplus_demangle_v3_callback, is_gnu_v3_mangled_ctor,
	is_gnu_v3_mangled_dtor, java_demangle_v3, java_demangle_v3_callback):
	Define.
	(__asan_internal_memcmp, __asan_internal_strncmp): New prototypes.
	(memcmp, strncmp): Redefine.
	* libbacktrace/Makefile.am (libsanitizer_libbacktrace_la_SOURCES): Add
	../../libiberty/cp-demangle.c.
	* libbacktrace/bridge.cc (__asan_internal_memcmp,
	__asan_internal_strncmp): New functions.
	* sanitizer_common/Makefile.in: Regenerated.
	* libbacktrace/Makefile.in: Regenerated.
	* configure: Regenerated.
	* configure.ac: Regenerated.
	* config.h.in: Regenerated.

From-SVN: r206477

13 files changed, 180 insertions, 11 deletions

diff --git a/libsanitizer/ChangeLog b/libsanitizer/ChangeLog
index 66a81e4..30a26bc 100644
--- a/libsanitizer/ChangeLog
+++ b/libsanitizer/ChangeLog
@@ -1,5 +1,39 @@
 2014-01-09  Jakub Jelinek  <jakub@redhat.com>
 
+	* sanitizer_common/sanitizer_symbolizer_libbacktrace.h
+	(LibbacktraceSymbolizer::Demangle): New declaration.
+	* sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
+	(POSIXSymbolizer::Demangle): Use libbacktrace_symbolizer_'s Demangle
+	method if possible.
+	* sanitizer_common/sanitizer_symbolizer_libbacktrace.cc: Include
+	"demangle.h" if SANITIZE_CP_DEMANGLE is defined.
+	(struct CplusV3DemangleData): New type.
+	(CplusV3DemangleCallback, CplusV3Demangle): New functions.
+	(SymbolizeCodePCInfoCallback, SymbolizeCodeCallback,
+	SymbolizeDataCallback): Use CplusV3Demangle.
+	* sanitizer_common/Makefile.am (AM_CXXFLAGS): Add
+	-DSANITIZE_CP_DEMANGLE and -I $(top_srcdir)/../include.
+	* libbacktrace/backtrace-rename.h (cplus_demangle_builtin_types,
+	cplus_demangle_fill_ctor, cplus_demangle_fill_dtor,
+	cplus_demangle_fill_extended_operator, cplus_demangle_fill_name,
+	cplus_demangle_init_info, cplus_demangle_mangled_name,
+	cplus_demangle_operators, cplus_demangle_print,
+	cplus_demangle_print_callback, cplus_demangle_type, cplus_demangle_v3,
+	cplus_demangle_v3_callback, is_gnu_v3_mangled_ctor,
+	is_gnu_v3_mangled_dtor, java_demangle_v3, java_demangle_v3_callback):
+	Define.
+	(__asan_internal_memcmp, __asan_internal_strncmp): New prototypes.
+	(memcmp, strncmp): Redefine.
+	* libbacktrace/Makefile.am (libsanitizer_libbacktrace_la_SOURCES): Add
+	../../libiberty/cp-demangle.c.
+	* libbacktrace/bridge.cc (__asan_internal_memcmp,
+	__asan_internal_strncmp): New functions.
+	* sanitizer_common/Makefile.in: Regenerated.
+	* libbacktrace/Makefile.in: Regenerated.
+	* configure: Regenerated.
+	* configure.ac: Regenerated.
+	* config.h.in: Regenerated.
+
 	* sanitizer_common/Makefile.am (AM_CPPFLAGS): Add
 	-isystem $(top_srcdir)/include/system.
 	* sanitizer_common/Makefile.in: Regenerated.
diff --git a/libsanitizer/config.h.in b/libsanitizer/config.h.in
index bb4bb8a..e4b2786 100644
--- a/libsanitizer/config.h.in
+++ b/libsanitizer/config.h.in
@@ -3,6 +3,9 @@
 /* ELF size: 32 or 64 */
 #undef BACKTRACE_ELF_SIZE
 
+/* Define to 1 if you have the <alloca.h> header file. */
+#undef HAVE_ALLOCA_H
+
 /* Define to 1 if you have the __atomic functions */
 #undef HAVE_ATOMIC_FUNCTIONS
 
diff --git a/libsanitizer/configure b/libsanitizer/configure
index bb20f12..c207359 100755
--- a/libsanitizer/configure
+++ b/libsanitizer/configure
@@ -16134,12 +16134,14 @@ ac_config_commands="$ac_config_commands gstdint.h"
 
 
 
-for ac_header in sys/mman.h
+for ac_header in sys/mman.h alloca.h
 do :
-  ac_fn_c_check_header_mongrel "$LINENO" "sys/mman.h" "ac_cv_header_sys_mman_h" "$ac_includes_default"
-if test "x$ac_cv_header_sys_mman_h" = x""yes; then :
+  as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
+ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
+eval as_val=\$$as_ac_Header
+   if test "x$as_val" = x""yes; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_SYS_MMAN_H 1
+#define `$as_echo "HAVE_$ac_header" | $as_tr_cpp` 1
 _ACEOF
 
 fi
diff --git a/libsanitizer/configure.ac b/libsanitizer/configure.ac
index ab4b216..c4641d4 100644
--- a/libsanitizer/configure.ac
+++ b/libsanitizer/configure.ac
@@ -208,7 +208,7 @@ AC_SUBST(BACKTRACE_SUPPORTED)
 
 GCC_HEADER_STDINT(gstdint.h)
 
-AC_CHECK_HEADERS(sys/mman.h)
+AC_CHECK_HEADERS(sys/mman.h alloca.h)
 if test "$ac_cv_header_sys_mman_h" = "no"; then
   have_mmap=no
 else
diff --git a/libsanitizer/libbacktrace/Makefile.am b/libsanitizer/libbacktrace/Makefile.am
index bde141c..39c91aa 100644
--- a/libsanitizer/libbacktrace/Makefile.am
+++ b/libsanitizer/libbacktrace/Makefile.am
@@ -51,6 +51,7 @@ libsanitizer_libbacktrace_la_SOURCES = \
 	../../libbacktrace/internal.h \
 	../../libbacktrace/posix.c \
 	../../libbacktrace/state.c \
+	../../libiberty/cp-demangle.c \
 	bridge.cc
 
 FORMAT_FILES = \
diff --git a/libsanitizer/libbacktrace/Makefile.in b/libsanitizer/libbacktrace/Makefile.in
index efbf618..3dca45b 100644
--- a/libsanitizer/libbacktrace/Makefile.in
+++ b/libsanitizer/libbacktrace/Makefile.in
@@ -90,7 +90,7 @@ CONFIG_CLEAN_VPATH_FILES =
 LTLIBRARIES = $(noinst_LTLIBRARIES)
 am__DEPENDENCIES_1 =
 am_libsanitizer_libbacktrace_la_OBJECTS = atomic.lo dwarf.lo \
-	fileline.lo posix.lo state.lo bridge.lo
+	fileline.lo posix.lo state.lo cp-demangle.lo bridge.lo
 libsanitizer_libbacktrace_la_OBJECTS =  \
 	$(am_libsanitizer_libbacktrace_la_OBJECTS)
 DEFAULT_INCLUDES = -I.@am__isrc@ -I$(top_builddir)
@@ -280,6 +280,7 @@ libsanitizer_libbacktrace_la_SOURCES = \
 	../../libbacktrace/internal.h \
 	../../libbacktrace/posix.c \
 	../../libbacktrace/state.c \
+	../../libiberty/cp-demangle.c \
 	bridge.cc
 
 FORMAT_FILES = \
@@ -362,6 +363,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/alloc.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/atomic.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/bridge.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/cp-demangle.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/dwarf.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/elf.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/fileline.Plo@am__quote@
@@ -428,6 +430,13 @@ state.lo: ../../libbacktrace/state.c
 @AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
 @am__fastdepCC_FALSE@	$(LIBTOOL)  --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -c -o state.lo `test -f '../../libbacktrace/state.c' || echo '$(srcdir)/'`../../libbacktrace/state.c
 
+cp-demangle.lo: ../../libiberty/cp-demangle.c
+@am__fastdepCC_TRUE@	$(LIBTOOL)  --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -MT cp-demangle.lo -MD -MP -MF $(DEPDIR)/cp-demangle.Tpo -c -o cp-demangle.lo `test -f '../../libiberty/cp-demangle.c' || echo '$(srcdir)/'`../../libiberty/cp-demangle.c
+@am__fastdepCC_TRUE@	$(am__mv) $(DEPDIR)/cp-demangle.Tpo $(DEPDIR)/cp-demangle.Plo
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	source='../../libiberty/cp-demangle.c' object='cp-demangle.lo' libtool=yes @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
+@am__fastdepCC_FALSE@	$(LIBTOOL)  --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -c -o cp-demangle.lo `test -f '../../libiberty/cp-demangle.c' || echo '$(srcdir)/'`../../libiberty/cp-demangle.c
+
 elf.lo: ../../libbacktrace/elf.c
 @am__fastdepCC_TRUE@	$(LIBTOOL)  --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) -MT elf.lo -MD -MP -MF $(DEPDIR)/elf.Tpo -c -o elf.lo `test -f '../../libbacktrace/elf.c' || echo '$(srcdir)/'`../../libbacktrace/elf.c
 @am__fastdepCC_TRUE@	$(am__mv) $(DEPDIR)/elf.Tpo $(DEPDIR)/elf.Plo
diff --git a/libsanitizer/libbacktrace/backtrace-rename.h b/libsanitizer/libbacktrace/backtrace-rename.h
index 08402c8..af8f36b 100644
--- a/libsanitizer/libbacktrace/backtrace-rename.h
+++ b/libsanitizer/libbacktrace/backtrace-rename.h
@@ -14,25 +14,49 @@
 #define backtrace_vector_grow __asan_backtrace_vector_grow
 #define backtrace_vector_release __asan_backtrace_vector_release
 
+#define cplus_demangle_builtin_types __asan_cplus_demangle_builtin_types
+#define cplus_demangle_fill_ctor __asan_cplus_demangle_fill_ctor
+#define cplus_demangle_fill_dtor __asan_cplus_demangle_fill_dtor
+#define cplus_demangle_fill_extended_operator __asan_cplus_demangle_fill_extended_operator
+#define cplus_demangle_fill_name __asan_cplus_demangle_fill_name
+#define cplus_demangle_init_info __asan_cplus_demangle_init_info
+#define cplus_demangle_mangled_name __asan_cplus_demangle_mangled_name
+#define cplus_demangle_operators __asan_cplus_demangle_operators
+#define cplus_demangle_print __asan_cplus_demangle_print
+#define cplus_demangle_print_callback __asan_cplus_demangle_print_callback
+#define cplus_demangle_type __asan_cplus_demangle_type
+#define cplus_demangle_v3 __asan_cplus_demangle_v3
+#define cplus_demangle_v3_callback __asan_cplus_demangle_v3_callback
+#define is_gnu_v3_mangled_ctor __asan_is_gnu_v3_mangled_ctor
+#define is_gnu_v3_mangled_dtor __asan_is_gnu_v3_mangled_dtor
+#define java_demangle_v3 __asan_java_demangle_v3
+#define java_demangle_v3_callback __asan_java_demangle_v3_callback
+
 #ifndef __cplusplus
 
 #include <string.h>
 
 extern void *__asan_internal_memcpy (void *, const void *, size_t);
 extern void *__asan_internal_memset (void *, int, size_t);
+extern int __asan_internal_memcmp (const void *, const void *, size_t);
 extern int __asan_internal_strcmp (const char *, const char *);
+extern int __asan_internal_strncmp (const char *, const char *, size_t);
 extern size_t __asan_internal_strlen (const char *);
 extern size_t __asan_internal_strnlen (const char *, size_t);
 
 #undef memcpy
 #undef memset
+#undef memcmp
 #undef strcmp
+#undef strncmp
 #undef strlen
 #undef strnlen
 
 #define memcpy(x,y,z) __asan_internal_memcpy (x, y, z)
 #define memset(x,y,z) __asan_internal_memset (x, y, z)
+#define memcmp(x,y,z) __asan_internal_memcmp (x, y, z)
 #define strcmp(x,y) __asan_internal_strcmp (x, y)
+#define strncmp(x,y,z) __asan_internal_strncmp (x, y, z)
 #define strlen(x) __asan_internal_strlen (x)
 #ifdef HAVE_DECL_STRNLEN
 #define strnlen(x,y) __asan_internal_strnlen (x, y)
diff --git a/libsanitizer/libbacktrace/bridge.cc b/libsanitizer/libbacktrace/bridge.cc
index 3f95898..d553c66 100644
--- a/libsanitizer/libbacktrace/bridge.cc
+++ b/libsanitizer/libbacktrace/bridge.cc
@@ -52,11 +52,23 @@ __asan_internal_memset (void *dest, int c, size_t n)
 }
 
 int
+__asan_internal_memcmp (const void *s1, const void *s2, size_t n)
+{
+  return __sanitizer::internal_memcmp (s1, s2, n);
+}
+
+int
 __asan_internal_strcmp (const char *s1, const char *s2)
 {
   return __sanitizer::internal_strcmp (s1, s2);
 }
 
+int
+__asan_internal_strncmp (const char *s1, const char *s2, size_t n)
+{
+  return __sanitizer::internal_strncmp (s1, s2, n);
+}
+
 size_t
 __asan_internal_strlen (const char *str)
 {
diff --git a/libsanitizer/sanitizer_common/Makefile.am b/libsanitizer/sanitizer_common/Makefile.am
index 11af196..8e9038d 100644
--- a/libsanitizer/sanitizer_common/Makefile.am
+++ b/libsanitizer/sanitizer_common/Makefile.am
@@ -7,8 +7,10 @@ DEFS = -D_GNU_SOURCE -D_DEBUG -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D
 AM_CXXFLAGS = -Wall -W -Wno-unused-parameter -Wwrite-strings -pedantic -Wno-long-long  -fPIC -fno-builtin -fno-exceptions -fno-rtti -fomit-frame-pointer -funwind-tables -fvisibility=hidden -Wno-variadic-macros
 AM_CXXFLAGS += $(LIBSTDCXX_RAW_CXX_CXXFLAGS)
 if LIBBACKTRACE_SUPPORTED
-AM_CXXFLAGS += -DSANITIZER_LIBBACKTRACE -I $(top_srcdir)/../libbacktrace \
+AM_CXXFLAGS += -DSANITIZER_LIBBACKTRACE -DSANITIZER_CP_DEMANGLE \
+	       -I $(top_srcdir)/../libbacktrace \
 	       -I $(top_builddir)/libbacktrace \
+	       -I $(top_srcdir)/../include \
 	       -include $(top_srcdir)/libbacktrace/backtrace-rename.h
 endif
 ACLOCAL_AMFLAGS = -I m4
diff --git a/libsanitizer/sanitizer_common/Makefile.in b/libsanitizer/sanitizer_common/Makefile.in
index e5dc5be..e9fd115 100644
--- a/libsanitizer/sanitizer_common/Makefile.in
+++ b/libsanitizer/sanitizer_common/Makefile.in
@@ -35,8 +35,10 @@ POST_UNINSTALL = :
 build_triplet = @build@
 host_triplet = @host@
 target_triplet = @target@
-@LIBBACKTRACE_SUPPORTED_TRUE@am__append_1 = -DSANITIZER_LIBBACKTRACE -I $(top_srcdir)/../libbacktrace \
+@LIBBACKTRACE_SUPPORTED_TRUE@am__append_1 = -DSANITIZER_LIBBACKTRACE -DSANITIZER_CP_DEMANGLE \
+@LIBBACKTRACE_SUPPORTED_TRUE@	       -I $(top_srcdir)/../libbacktrace \
 @LIBBACKTRACE_SUPPORTED_TRUE@	       -I $(top_builddir)/libbacktrace \
+@LIBBACKTRACE_SUPPORTED_TRUE@	       -I $(top_srcdir)/../include \
 @LIBBACKTRACE_SUPPORTED_TRUE@	       -include $(top_srcdir)/libbacktrace/backtrace-rename.h
 
 subdir = sanitizer_common
diff --git a/libsanitizer/sanitizer_common/sanitizer_symbolizer_libbacktrace.cc b/libsanitizer/sanitizer_common/sanitizer_symbolizer_libbacktrace.cc
index 5654d1d..3023002 100644
--- a/libsanitizer/sanitizer_common/sanitizer_symbolizer_libbacktrace.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_symbolizer_libbacktrace.cc
@@ -20,6 +20,10 @@
 # include "backtrace-supported.h"
 # if SANITIZER_POSIX && BACKTRACE_SUPPORTED && !BACKTRACE_USES_MALLOC
 #  include "backtrace.h"
+#  if SANITIZER_CP_DEMANGLE
+#   undef ARRAY_SIZE
+#   include "demangle.h"
+#  endif
 # else
 #  define SANITIZER_LIBBACKTRACE 0
 # endif
@@ -31,6 +35,60 @@ namespace __sanitizer {
 
 namespace {
 
+#if SANITIZER_CP_DEMANGLE
+struct CplusV3DemangleData {
+  char *buf;
+  uptr size, allocated;
+};
+
+extern "C" {
+static void CplusV3DemangleCallback(const char *s, size_t l, void *vdata) {
+  CplusV3DemangleData *data = (CplusV3DemangleData *)vdata;
+  uptr needed = data->size + l + 1;
+  if (needed > data->allocated) {
+    data->allocated *= 2;
+    if (needed > data->allocated)
+      data->allocated = needed;
+    char *buf = (char *)InternalAlloc(data->allocated);
+    if (data->buf) {
+      internal_memcpy(buf, data->buf, data->size);
+      InternalFree(data->buf);
+    }
+    data->buf = buf;
+  }
+  internal_memcpy(data->buf + data->size, s, l);
+  data->buf[data->size + l] = '\0';
+  data->size += l;
+}
+}  // extern "C"
+
+char *CplusV3Demangle(const char *name, bool always_alloc) {
+  CplusV3DemangleData data;
+  data.buf = 0;
+  data.size = 0;
+  data.allocated = 0;
+  if (cplus_demangle_v3_callback(name, DMGL_PARAMS | DMGL_ANSI,
+				 CplusV3DemangleCallback, &data)) {
+    if (data.size + 64 > data.allocated)
+      return data.buf;
+    char *buf = internal_strdup(data.buf);
+    InternalFree(data.buf);
+    return buf;
+  }
+  if (data.buf)
+    InternalFree(data.buf);
+  if (always_alloc)
+    return internal_strdup(name);
+  return 0;
+}
+#else
+const char *CplusV3Demangle(const char *name, bool always_alloc) {
+  if (always_alloc)
+    return internal_strdup(name);
+  return 0;
+}
+#endif
+
 struct SymbolizeCodeData {
   AddressInfo *frames;
   uptr n_frames;
@@ -49,7 +107,7 @@ static int SymbolizeCodePCInfoCallback(void *vdata, uintptr_t addr,
     info->Clear();
     info->FillAddressAndModuleInfo(addr, cdata->module_name,
                                    cdata->module_offset);
-    info->function = internal_strdup(function);
+    info->function = CplusV3Demangle(function, true);
     if (filename)
       info->file = internal_strdup(filename);
     info->line = lineno;
@@ -67,7 +125,7 @@ static void SymbolizeCodeCallback(void *vdata, uintptr_t addr,
     info->Clear();
     info->FillAddressAndModuleInfo(addr, cdata->module_name,
                                    cdata->module_offset);
-    info->function = internal_strdup(symname);
+    info->function = CplusV3Demangle(symname, true);
     cdata->n_frames = 1;
   }
 }
@@ -76,7 +134,7 @@ static void SymbolizeDataCallback(void *vdata, uintptr_t, const char *symname,
                                   uintptr_t symval, uintptr_t symsize) {
   DataInfo *info = (DataInfo *)vdata;
   if (symname && symval) {
-    info->name = internal_strdup(symname);
+    info->name = CplusV3Demangle(symname, true);
     info->start = symval;
     info->size = symsize;
   }
@@ -121,6 +179,17 @@ bool LibbacktraceSymbolizer::SymbolizeData(DataInfo *info) {
   return true;
 }
 
+const char *LibbacktraceSymbolizer::Demangle(const char *name) {
+#if SANITIZER_CP_DEMANGLE
+  const char *demangled = CplusV3Demangle(name, false);
+  if (demangled)
+    return demangled;
+  return name;
+#else
+  return 0;
+#endif
+}
+
 #else  // SANITIZER_LIBBACKTRACE
 
 LibbacktraceSymbolizer *LibbacktraceSymbolizer::get(LowLevelAllocator *alloc) {
@@ -139,6 +208,10 @@ bool LibbacktraceSymbolizer::SymbolizeData(DataInfo *info) {
   return false;
 }
 
+const char *LibbacktraceSymbolizer::Demangle(const char *name) {
+  return 0;
+}
+
 #endif  // SANITIZER_LIBBACKTRACE
 
 }  // namespace __sanitizer
diff --git a/libsanitizer/sanitizer_common/sanitizer_symbolizer_libbacktrace.h b/libsanitizer/sanitizer_common/sanitizer_symbolizer_libbacktrace.h
index f09cea5..05f0558 100644
--- a/libsanitizer/sanitizer_common/sanitizer_symbolizer_libbacktrace.h
+++ b/libsanitizer/sanitizer_common/sanitizer_symbolizer_libbacktrace.h
@@ -29,6 +29,8 @@ class LibbacktraceSymbolizer {
 
   bool SymbolizeData(DataInfo *info);
 
+  const char *Demangle(const char *name);
+
  private:
   explicit LibbacktraceSymbolizer(void *state) : state_(state) {}
 
diff --git a/libsanitizer/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
index 9f34b64..7aead97 100644
--- a/libsanitizer/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
@@ -513,6 +513,11 @@ class POSIXSymbolizer : public Symbolizer {
     SymbolizerScope sym_scope(this);
     if (internal_symbolizer_ != 0)
       return internal_symbolizer_->Demangle(name);
+    if (libbacktrace_symbolizer_ != 0) {
+      const char *demangled = libbacktrace_symbolizer_->Demangle(name);
+      if (demangled)
+	return demangled;
+    }
     return DemangleCXXABI(name);
   }