From: Denis Khalikov <d.khalikov@partner.samsung.com>
Date: Sat, 29 Jul 2017 19:18:59 +0000 (+0300)
Subject: PR sanitizer/77631
X-Git-Tag: accepted/tizen/base/20170908.223816~5
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=refs%2Fchanges%2F56%2F134256%2F16;p=platform%2Fupstream%2Flinaro-gcc.git

PR sanitizer/77631

    * Makefile.am: Updated.
    * configure.ac: Updated.
    * configure: Regenerated.
    * Makefile.in: Regenerated.
    * elf.c (enum type_of_file): New enum.
    (enum type_of_elf): New enum.
    (enum debug_path): New enum.
    (get_uint32): New function.
    (get_crc32): New function.
    (base_name_len): New function.
    (check_sum): New function. Verify sum.
    (process_elf_header): New function. Process elf header.
    (elf_get_section_by_name): New function. Get section by name.
    (backtrace_readlink): New function. Get type of file from filename.
    (resolve_realname): New function. Resolve real name if file is link.
    (backtrace_resolve_realname): New function. Resolve real name for any
    file type.
    (search_for_debugfile): New function. Search for debug file in known
    paths.
    (open_debugfile_by_gnulink): New function. Open debug file with
    gnulink.
    (hex): New function. Convert to hex.
    (get_build_id_name): New function. Generate build-id name.
    (open_debugfile_by_build_id): New function. Open debug file with
    build-id.
    (backtrace_open_debugfile): New function. Open debug file.
    (get_exec_filename): New function. Get pathname of the executable.
    (elf_add): Move code which reads elf header, headers section and names
    section to process_elf_header.
    Call backtrace_open_debugfile_file for executable.
    (phdr_callback): Call backtrace_open_debugfile function for shared
    library.
    * crc32.c: New file.
    (gnu_debuglink_crc32): New function. Generate crc32 sum.

Change-Id: I30d9fbcfa24b3aadf3b7c54525dccedd60cd1a5d
---

diff --git a/libbacktrace/ChangeLog b/libbacktrace/ChangeLog
index 4cb639b..c2546be 100644
--- a/libbacktrace/ChangeLog
+++ b/libbacktrace/ChangeLog
@@ -1,3 +1,42 @@
+2017-07-29 Denis Khalikov <d.khalikov@partner.samsung.com>
+
+    PR sanitizer/77631
+    * Makefile.am: Updated.
+    * configure.ac: Updated.
+    * configure: Regenerated.
+    * Makefile.in: Regenerated.
+    * elf.c (enum type_of_file): New enum.
+    (enum type_of_elf): New enum.
+    (enum debug_path): New enum.
+    (get_uint32): New function.
+    (get_crc32): New function.
+    (base_name_len): New function.
+    (check_sum): New function. Verify sum.
+    (process_elf_header): New function. Process elf header.
+    (elf_get_section_by_name): New function. Get section by name.
+    (backtrace_readlink): New function. Get type of file from filename.
+    (resolve_realname): New function. Resolve real name if file is link.
+    (backtrace_resolve_realname): New function. Resolve real name for any
+    file type.
+    (search_for_debugfile): New function. Search for debug file in known
+    paths.
+    (open_debugfile_by_gnulink): New function. Open debug file with
+    gnulink.
+    (hex): New function. Convert to hex.
+    (get_build_id_name): New function. Generate build-id name.
+    (open_debugfile_by_build_id): New function. Open debug file with
+    build-id.
+    (backtrace_open_debugfile): New function. Open debug file.
+    (get_exec_filename): New function. Get pathname of the executable.
+    (elf_add): Move code which reads elf header, headers section and names
+    section to process_elf_header.
+    Call backtrace_open_debugfile_file for executable.
+    (phdr_callback): Call backtrace_open_debugfile function for shared
+    library.
+    * crc32.c: New file.
+    (gnu_debuglink_crc32): New function. Generate crc32 sum.
+
+
 2016-12-21  Release Manager
 
 	* GCC 6.3.0 released.
diff --git a/libbacktrace/Makefile.am b/libbacktrace/Makefile.am
index a7df025..61f1804 100644
--- a/libbacktrace/Makefile.am
+++ b/libbacktrace/Makefile.am
@@ -100,8 +100,161 @@ stest_LDADD = libbacktrace.la
 
 check_PROGRAMS += stest
 
-endif NATIVE
+glinktest_SOURCES = btest.c
+glinktest_CFLAGS = $(AM_CFLAGS) -g -O
+glinktest_LDADD = libbacktrace.la
+
+check_PROGRAMS += glinktest
+
+bidtest_SOURCES = btest.c
+bidtest_CFLAGS = $(AM_CFLAGS) -g -O -Wl,--build-id=0x0123456789abcdef0123456789abcdef01234567
+bidtest_LDADD = libbacktrace.la
+
+check_PROGRAMS += bidtest
+
+pictest_SOURCES = btest.c
+pictest_CFLAGS = $(AM_CFLAGS) -g -O -fPIC -pie
+pictest_LDADD = libbacktrace.la
 
+check_PROGRAMS += pictest
+
+check-TESTS: $(TESTS)
+	@failed=0; all=0; xfail=0; xpass=0; skip=0; \
+	srcdir=$(srcdir); export srcdir; \
+	list=' $(TESTS) '; \
+	$(am__tty_colors); \
+	if ! test -e glinktest.debug; then \
+	  $(OBJCOPY) --only-keep-debug glinktest glinktest.debug; \
+	  $(STRIP) glinktest; \
+	  $(OBJCOPY) --add-gnu-debuglink=glinktest.debug glinktest; \
+	fi; \
+	if ! test -e pictest.debug; then \
+	  $(OBJCOPY) --only-keep-debug pictest pictest.debug; \
+	  $(STRIP) pictest; \
+	  $(OBJCOPY) --add-gnu-debuglink=pictest.debug pictest; \
+	fi; \
+	if ! test -e .build-id; then \
+	  mkdir .build-id; \
+	  mkdir .build-id/01/; \
+	  mkdir temp; \
+	  $(OBJCOPY) --only-keep-debug bidtest bidtest.debug; \
+	  $(STRIP) bidtest; \
+	  touch temp; \
+	  mv bidtest.debug temp;\
+	  ln -s ../../temp/bidtest.debug .build-id/01/23456789abcdef0123456789abcdef01234567.debug; \
+	fi; \
+	if test -n "$$list"; then \
+	  for tst in $$list; do \
+	    if test -f ./$$tst; then dir=./; \
+	    elif test -f $$tst; then dir=; \
+	    else dir="$(srcdir)/"; fi; \
+	    if $(TESTS_ENVIRONMENT) $${dir}$$tst; then \
+	      all=`expr $$all + 1`; \
+	      case " $(XFAIL_TESTS) " in \
+	      *[\ \	]$$tst[\ \	]*) \
+		xpass=`expr $$xpass + 1`; \
+		failed=`expr $$failed + 1`; \
+		col=$$red; res=XPASS; \
+	      ;; \
+	      *) \
+		col=$$grn; res=PASS; \
+	      ;; \
+	      esac; \
+	    elif test $$? -ne 77; then \
+	      all=`expr $$all + 1`; \
+	      case " $(XFAIL_TESTS) " in \
+	      *[\ \	]$$tst[\ \	]*) \
+		xfail=`expr $$xfail + 1`; \
+		col=$$lgn; res=XFAIL; \
+	      ;; \
+	      *) \
+		failed=`expr $$failed + 1`; \
+		col=$$red; res=FAIL; \
+	      ;; \
+	      esac; \
+	    else \
+	      skip=`expr $$skip + 1`; \
+	      col=$$blu; res=SKIP; \
+	    fi; \
+	    echo "$${col}$$res$${std}: $$tst"; \
+	  done; \
+	  if test "$$all" -eq 1; then \
+	    tests="test"; \
+	    All=""; \
+	  else \
+	    tests="tests"; \
+	    All="All "; \
+	  fi; \
+	  if test "$$failed" -eq 0; then \
+	    if test "$$xfail" -eq 0; then \
+	      banner="$$All$$all $$tests passed"; \
+	    else \
+	      if test "$$xfail" -eq 1; then failures=failure; else failures=failures; fi; \
+	      banner="$$All$$all $$tests behaved as expected ($$xfail expected $$failures)"; \
+	    fi; \
+	  else \
+	    if test "$$xpass" -eq 0; then \
+	      banner="$$failed of $$all $$tests failed"; \
+	    else \
+	      if test "$$xpass" -eq 1; then passes=pass; else passes=passes; fi; \
+	      banner="$$failed of $$all $$tests did not behave as expected ($$xpass unexpected $$passes)"; \
+	    fi; \
+	  fi; \
+	  dashes="$$banner"; \
+	  skipped=""; \
+	  if test "$$skip" -ne 0; then \
+	    if test "$$skip" -eq 1; then \
+	      skipped="($$skip test was not run)"; \
+	    else \
+	      skipped="($$skip tests were not run)"; \
+	    fi; \
+	    test `echo "$$skipped" | wc -c` -le `echo "$$banner" | wc -c` || \
+	      dashes="$$skipped"; \
+	  fi; \
+	  report=""; \
+	  if test "$$failed" -ne 0 && test -n "$(PACKAGE_BUGREPORT)"; then \
+	    report="Please report to $(PACKAGE_BUGREPORT)"; \
+	    test `echo "$$report" | wc -c` -le `echo "$$banner" | wc -c` || \
+	      dashes="$$report"; \
+	  fi; \
+	  dashes=`echo "$$dashes" | sed s/./=/g`; \
+	  if test "$$failed" -eq 0; then \
+	    col="$$grn"; \
+	  else \
+	    col="$$red"; \
+	  fi; \
+	  echo "$${col}$$dashes$${std}"; \
+	  echo "$${col}$$banner$${std}"; \
+	  test -z "$$skipped" || echo "$${col}$$skipped$${std}"; \
+	  test -z "$$report" || echo "$${col}$$report$${std}"; \
+	  echo "$${col}$$dashes$${std}"; \
+	  test "$$failed" -eq 0; \
+	else :; fi
+
+
+clean-checkPROGRAMS:
+	@if test -e glinktest.debug; then \
+	 echo "rm -f glinktest.debug pictest.debug"; \
+	 rm -f glinktest.debug pictest.debug; \
+	fi; \
+	if test -d temp; then \
+	 echo "rm -rf temp"; \
+	 rm -rf temp; \
+	fi; \
+	if test -d .build-id; then \
+	  echo "rm -rf .build-id"; \
+	  rm -rf .build-id; \
+	fi; \
+	list='$(check_PROGRAMS)'; \
+	test -n "$$list" || exit 0; \
+	echo " rm -f" $$list; \
+	rm -f $$list || exit $$?; \
+	test -n "$(EXEEXT)" || exit 0; \
+	list=`for p in $$list; do echo "$$p"; done | sed 's/$(EXEEXT)$$//'`; \
+	echo " rm -f" $$list; \
+	rm -f $$list;
+
+endif NATIVE
 # We can't use automake's automatic dependency tracking, because it
 # breaks when using bootstrap-lean.  Automatic dependency tracking
 # with GCC bootstrap will cause some of the objects to depend on
diff --git a/libbacktrace/Makefile.in b/libbacktrace/Makefile.in
index 586b6a6..1f51c4e 100644
--- a/libbacktrace/Makefile.in
+++ b/libbacktrace/Makefile.in
@@ -16,7 +16,7 @@
 @SET_MAKE@
 
 # Makefile.am -- Backtrace Makefile.
-# Copyright (C) 2012-2015 Free Software Foundation, Inc.
+# Copyright (C) 2012-2016 Free Software Foundation, Inc.
 
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
@@ -84,7 +84,7 @@ build_triplet = @build@
 host_triplet = @host@
 target_triplet = @target@
 check_PROGRAMS = $(am__EXEEXT_1)
-@NATIVE_TRUE@am__append_1 = btest stest
+@NATIVE_TRUE@am__append_1 = btest stest glinktest bidtest pictest
 subdir = .
 DIST_COMMON = README ChangeLog $(srcdir)/Makefile.in \
 	$(srcdir)/Makefile.am $(top_srcdir)/configure \
@@ -113,13 +113,33 @@ am__DEPENDENCIES_1 =
 am_libbacktrace_la_OBJECTS = atomic.lo dwarf.lo fileline.lo posix.lo \
 	print.lo sort.lo state.lo
 libbacktrace_la_OBJECTS = $(am_libbacktrace_la_OBJECTS)
-@NATIVE_TRUE@am__EXEEXT_1 = btest$(EXEEXT) stest$(EXEEXT)
+@NATIVE_TRUE@am__EXEEXT_1 = btest$(EXEEXT) stest$(EXEEXT) \
+@NATIVE_TRUE@	glinktest$(EXEEXT) bidtest$(EXEEXT) \
+@NATIVE_TRUE@	pictest$(EXEEXT)
+@NATIVE_TRUE@am_bidtest_OBJECTS = bidtest-btest.$(OBJEXT)
+bidtest_OBJECTS = $(am_bidtest_OBJECTS)
+@NATIVE_TRUE@bidtest_DEPENDENCIES = libbacktrace.la
+bidtest_LINK = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
+	--mode=link $(CCLD) $(bidtest_CFLAGS) $(CFLAGS) $(AM_LDFLAGS) \
+	$(LDFLAGS) -o $@
 @NATIVE_TRUE@am_btest_OBJECTS = btest-btest.$(OBJEXT)
 btest_OBJECTS = $(am_btest_OBJECTS)
 @NATIVE_TRUE@btest_DEPENDENCIES = libbacktrace.la
 btest_LINK = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
 	--mode=link $(CCLD) $(btest_CFLAGS) $(CFLAGS) $(AM_LDFLAGS) \
 	$(LDFLAGS) -o $@
+@NATIVE_TRUE@am_glinktest_OBJECTS = glinktest-btest.$(OBJEXT)
+glinktest_OBJECTS = $(am_glinktest_OBJECTS)
+@NATIVE_TRUE@glinktest_DEPENDENCIES = libbacktrace.la
+glinktest_LINK = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) \
+	$(LIBTOOLFLAGS) --mode=link $(CCLD) $(glinktest_CFLAGS) \
+	$(CFLAGS) $(AM_LDFLAGS) $(LDFLAGS) -o $@
+@NATIVE_TRUE@am_pictest_OBJECTS = pictest-btest.$(OBJEXT)
+pictest_OBJECTS = $(am_pictest_OBJECTS)
+@NATIVE_TRUE@pictest_DEPENDENCIES = libbacktrace.la
+pictest_LINK = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
+	--mode=link $(CCLD) $(pictest_CFLAGS) $(CFLAGS) $(AM_LDFLAGS) \
+	$(LDFLAGS) -o $@
 @NATIVE_TRUE@am_stest_OBJECTS = stest.$(OBJEXT)
 stest_OBJECTS = $(am_stest_OBJECTS)
 @NATIVE_TRUE@stest_DEPENDENCIES = libbacktrace.la
@@ -136,7 +156,8 @@ LINK = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
 	--mode=link $(CCLD) $(AM_CFLAGS) $(CFLAGS) $(AM_LDFLAGS) \
 	$(LDFLAGS) -o $@
 SOURCES = $(libbacktrace_la_SOURCES) $(EXTRA_libbacktrace_la_SOURCES) \
-	$(btest_SOURCES) $(stest_SOURCES)
+	$(bidtest_SOURCES) $(btest_SOURCES) $(glinktest_SOURCES) \
+	$(pictest_SOURCES) $(stest_SOURCES)
 MULTISRCTOP = 
 MULTIBUILDTOP = 
 MULTIDIRS = 
@@ -200,6 +221,7 @@ MAKEINFO = @MAKEINFO@
 MKDIR_P = @MKDIR_P@
 NM = @NM@
 NMEDIT = @NMEDIT@
+OBJCOPY = @OBJCOPY@
 OBJDUMP = @OBJDUMP@
 OBJEXT = @OBJEXT@
 OTOOL = @OTOOL@
@@ -330,6 +352,15 @@ TESTS = $(check_PROGRAMS)
 @NATIVE_TRUE@btest_LDADD = libbacktrace.la
 @NATIVE_TRUE@stest_SOURCES = stest.c
 @NATIVE_TRUE@stest_LDADD = libbacktrace.la
+@NATIVE_TRUE@glinktest_SOURCES = btest.c
+@NATIVE_TRUE@glinktest_CFLAGS = $(AM_CFLAGS) -g -O
+@NATIVE_TRUE@glinktest_LDADD = libbacktrace.la
+@NATIVE_TRUE@bidtest_SOURCES = btest.c
+@NATIVE_TRUE@bidtest_CFLAGS = $(AM_CFLAGS) -g -O -Wl,--build-id=0x0123456789abcdef0123456789abcdef01234567
+@NATIVE_TRUE@bidtest_LDADD = libbacktrace.la
+@NATIVE_TRUE@pictest_SOURCES = btest.c
+@NATIVE_TRUE@pictest_CFLAGS = $(AM_CFLAGS) -g -O -fPIC -pie
+@NATIVE_TRUE@pictest_LDADD = libbacktrace.la
 
 # We can't use automake's automatic dependency tracking, because it
 # breaks when using bootstrap-lean.  Automatic dependency tracking
@@ -411,17 +442,26 @@ clean-noinstLTLIBRARIES:
 libbacktrace.la: $(libbacktrace_la_OBJECTS) $(libbacktrace_la_DEPENDENCIES) $(EXTRA_libbacktrace_la_DEPENDENCIES) 
 	$(LINK)  $(libbacktrace_la_OBJECTS) $(libbacktrace_la_LIBADD) $(LIBS)
 
-clean-checkPROGRAMS:
-	@list='$(check_PROGRAMS)'; test -n "$$list" || exit 0; \
-	echo " rm -f" $$list; \
-	rm -f $$list || exit $$?; \
-	test -n "$(EXEEXT)" || exit 0; \
-	list=`for p in $$list; do echo "$$p"; done | sed 's/$(EXEEXT)$$//'`; \
-	echo " rm -f" $$list; \
-	rm -f $$list
+@NATIVE_FALSE@clean-checkPROGRAMS:
+@NATIVE_FALSE@	@list='$(check_PROGRAMS)'; test -n "$$list" || exit 0; \
+@NATIVE_FALSE@	echo " rm -f" $$list; \
+@NATIVE_FALSE@	rm -f $$list || exit $$?; \
+@NATIVE_FALSE@	test -n "$(EXEEXT)" || exit 0; \
+@NATIVE_FALSE@	list=`for p in $$list; do echo "$$p"; done | sed 's/$(EXEEXT)$$//'`; \
+@NATIVE_FALSE@	echo " rm -f" $$list; \
+@NATIVE_FALSE@	rm -f $$list
+bidtest$(EXEEXT): $(bidtest_OBJECTS) $(bidtest_DEPENDENCIES) $(EXTRA_bidtest_DEPENDENCIES) 
+	@rm -f bidtest$(EXEEXT)
+	$(bidtest_LINK) $(bidtest_OBJECTS) $(bidtest_LDADD) $(LIBS)
 btest$(EXEEXT): $(btest_OBJECTS) $(btest_DEPENDENCIES) $(EXTRA_btest_DEPENDENCIES) 
 	@rm -f btest$(EXEEXT)
 	$(btest_LINK) $(btest_OBJECTS) $(btest_LDADD) $(LIBS)
+glinktest$(EXEEXT): $(glinktest_OBJECTS) $(glinktest_DEPENDENCIES) $(EXTRA_glinktest_DEPENDENCIES) 
+	@rm -f glinktest$(EXEEXT)
+	$(glinktest_LINK) $(glinktest_OBJECTS) $(glinktest_LDADD) $(LIBS)
+pictest$(EXEEXT): $(pictest_OBJECTS) $(pictest_DEPENDENCIES) $(EXTRA_pictest_DEPENDENCIES) 
+	@rm -f pictest$(EXEEXT)
+	$(pictest_LINK) $(pictest_OBJECTS) $(pictest_LDADD) $(LIBS)
 stest$(EXEEXT): $(stest_OBJECTS) $(stest_DEPENDENCIES) $(EXTRA_stest_DEPENDENCIES) 
 	@rm -f stest$(EXEEXT)
 	$(LINK) $(stest_OBJECTS) $(stest_LDADD) $(LIBS)
@@ -441,12 +481,30 @@ distclean-compile:
 .c.lo:
 	$(LTCOMPILE) -c -o $@ $<
 
+bidtest-btest.o: btest.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(bidtest_CFLAGS) $(CFLAGS) -c -o bidtest-btest.o `test -f 'btest.c' || echo '$(srcdir)/'`btest.c
+
+bidtest-btest.obj: btest.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(bidtest_CFLAGS) $(CFLAGS) -c -o bidtest-btest.obj `if test -f 'btest.c'; then $(CYGPATH_W) 'btest.c'; else $(CYGPATH_W) '$(srcdir)/btest.c'; fi`
+
 btest-btest.o: btest.c
 	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(btest_CFLAGS) $(CFLAGS) -c -o btest-btest.o `test -f 'btest.c' || echo '$(srcdir)/'`btest.c
 
 btest-btest.obj: btest.c
 	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(btest_CFLAGS) $(CFLAGS) -c -o btest-btest.obj `if test -f 'btest.c'; then $(CYGPATH_W) 'btest.c'; else $(CYGPATH_W) '$(srcdir)/btest.c'; fi`
 
+glinktest-btest.o: btest.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(glinktest_CFLAGS) $(CFLAGS) -c -o glinktest-btest.o `test -f 'btest.c' || echo '$(srcdir)/'`btest.c
+
+glinktest-btest.obj: btest.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(glinktest_CFLAGS) $(CFLAGS) -c -o glinktest-btest.obj `if test -f 'btest.c'; then $(CYGPATH_W) 'btest.c'; else $(CYGPATH_W) '$(srcdir)/btest.c'; fi`
+
+pictest-btest.o: btest.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(pictest_CFLAGS) $(CFLAGS) -c -o pictest-btest.o `test -f 'btest.c' || echo '$(srcdir)/'`btest.c
+
+pictest-btest.obj: btest.c
+	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(pictest_CFLAGS) $(CFLAGS) -c -o pictest-btest.obj `if test -f 'btest.c'; then $(CYGPATH_W) 'btest.c'; else $(CYGPATH_W) '$(srcdir)/btest.c'; fi`
+
 mostlyclean-libtool:
 	-rm -f *.lo
 
@@ -525,98 +583,98 @@ GTAGS:
 distclean-tags:
 	-rm -f TAGS ID GTAGS GRTAGS GSYMS GPATH tags
 
-check-TESTS: $(TESTS)
-	@failed=0; all=0; xfail=0; xpass=0; skip=0; \
-	srcdir=$(srcdir); export srcdir; \
-	list=' $(TESTS) '; \
-	$(am__tty_colors); \
-	if test -n "$$list"; then \
-	  for tst in $$list; do \
-	    if test -f ./$$tst; then dir=./; \
-	    elif test -f $$tst; then dir=; \
-	    else dir="$(srcdir)/"; fi; \
-	    if $(TESTS_ENVIRONMENT) $${dir}$$tst; then \
-	      all=`expr $$all + 1`; \
-	      case " $(XFAIL_TESTS) " in \
-	      *[\ \	]$$tst[\ \	]*) \
-		xpass=`expr $$xpass + 1`; \
-		failed=`expr $$failed + 1`; \
-		col=$$red; res=XPASS; \
-	      ;; \
-	      *) \
-		col=$$grn; res=PASS; \
-	      ;; \
-	      esac; \
-	    elif test $$? -ne 77; then \
-	      all=`expr $$all + 1`; \
-	      case " $(XFAIL_TESTS) " in \
-	      *[\ \	]$$tst[\ \	]*) \
-		xfail=`expr $$xfail + 1`; \
-		col=$$lgn; res=XFAIL; \
-	      ;; \
-	      *) \
-		failed=`expr $$failed + 1`; \
-		col=$$red; res=FAIL; \
-	      ;; \
-	      esac; \
-	    else \
-	      skip=`expr $$skip + 1`; \
-	      col=$$blu; res=SKIP; \
-	    fi; \
-	    echo "$${col}$$res$${std}: $$tst"; \
-	  done; \
-	  if test "$$all" -eq 1; then \
-	    tests="test"; \
-	    All=""; \
-	  else \
-	    tests="tests"; \
-	    All="All "; \
-	  fi; \
-	  if test "$$failed" -eq 0; then \
-	    if test "$$xfail" -eq 0; then \
-	      banner="$$All$$all $$tests passed"; \
-	    else \
-	      if test "$$xfail" -eq 1; then failures=failure; else failures=failures; fi; \
-	      banner="$$All$$all $$tests behaved as expected ($$xfail expected $$failures)"; \
-	    fi; \
-	  else \
-	    if test "$$xpass" -eq 0; then \
-	      banner="$$failed of $$all $$tests failed"; \
-	    else \
-	      if test "$$xpass" -eq 1; then passes=pass; else passes=passes; fi; \
-	      banner="$$failed of $$all $$tests did not behave as expected ($$xpass unexpected $$passes)"; \
-	    fi; \
-	  fi; \
-	  dashes="$$banner"; \
-	  skipped=""; \
-	  if test "$$skip" -ne 0; then \
-	    if test "$$skip" -eq 1; then \
-	      skipped="($$skip test was not run)"; \
-	    else \
-	      skipped="($$skip tests were not run)"; \
-	    fi; \
-	    test `echo "$$skipped" | wc -c` -le `echo "$$banner" | wc -c` || \
-	      dashes="$$skipped"; \
-	  fi; \
-	  report=""; \
-	  if test "$$failed" -ne 0 && test -n "$(PACKAGE_BUGREPORT)"; then \
-	    report="Please report to $(PACKAGE_BUGREPORT)"; \
-	    test `echo "$$report" | wc -c` -le `echo "$$banner" | wc -c` || \
-	      dashes="$$report"; \
-	  fi; \
-	  dashes=`echo "$$dashes" | sed s/./=/g`; \
-	  if test "$$failed" -eq 0; then \
-	    col="$$grn"; \
-	  else \
-	    col="$$red"; \
-	  fi; \
-	  echo "$${col}$$dashes$${std}"; \
-	  echo "$${col}$$banner$${std}"; \
-	  test -z "$$skipped" || echo "$${col}$$skipped$${std}"; \
-	  test -z "$$report" || echo "$${col}$$report$${std}"; \
-	  echo "$${col}$$dashes$${std}"; \
-	  test "$$failed" -eq 0; \
-	else :; fi
+@NATIVE_FALSE@check-TESTS: $(TESTS)
+@NATIVE_FALSE@	@failed=0; all=0; xfail=0; xpass=0; skip=0; \
+@NATIVE_FALSE@	srcdir=$(srcdir); export srcdir; \
+@NATIVE_FALSE@	list=' $(TESTS) '; \
+@NATIVE_FALSE@	$(am__tty_colors); \
+@NATIVE_FALSE@	if test -n "$$list"; then \
+@NATIVE_FALSE@	  for tst in $$list; do \
+@NATIVE_FALSE@	    if test -f ./$$tst; then dir=./; \
+@NATIVE_FALSE@	    elif test -f $$tst; then dir=; \
+@NATIVE_FALSE@	    else dir="$(srcdir)/"; fi; \
+@NATIVE_FALSE@	    if $(TESTS_ENVIRONMENT) $${dir}$$tst; then \
+@NATIVE_FALSE@	      all=`expr $$all + 1`; \
+@NATIVE_FALSE@	      case " $(XFAIL_TESTS) " in \
+@NATIVE_FALSE@	      *[\ \	]$$tst[\ \	]*) \
+@NATIVE_FALSE@		xpass=`expr $$xpass + 1`; \
+@NATIVE_FALSE@		failed=`expr $$failed + 1`; \
+@NATIVE_FALSE@		col=$$red; res=XPASS; \
+@NATIVE_FALSE@	      ;; \
+@NATIVE_FALSE@	      *) \
+@NATIVE_FALSE@		col=$$grn; res=PASS; \
+@NATIVE_FALSE@	      ;; \
+@NATIVE_FALSE@	      esac; \
+@NATIVE_FALSE@	    elif test $$? -ne 77; then \
+@NATIVE_FALSE@	      all=`expr $$all + 1`; \
+@NATIVE_FALSE@	      case " $(XFAIL_TESTS) " in \
+@NATIVE_FALSE@	      *[\ \	]$$tst[\ \	]*) \
+@NATIVE_FALSE@		xfail=`expr $$xfail + 1`; \
+@NATIVE_FALSE@		col=$$lgn; res=XFAIL; \
+@NATIVE_FALSE@	      ;; \
+@NATIVE_FALSE@	      *) \
+@NATIVE_FALSE@		failed=`expr $$failed + 1`; \
+@NATIVE_FALSE@		col=$$red; res=FAIL; \
+@NATIVE_FALSE@	      ;; \
+@NATIVE_FALSE@	      esac; \
+@NATIVE_FALSE@	    else \
+@NATIVE_FALSE@	      skip=`expr $$skip + 1`; \
+@NATIVE_FALSE@	      col=$$blu; res=SKIP; \
+@NATIVE_FALSE@	    fi; \
+@NATIVE_FALSE@	    echo "$${col}$$res$${std}: $$tst"; \
+@NATIVE_FALSE@	  done; \
+@NATIVE_FALSE@	  if test "$$all" -eq 1; then \
+@NATIVE_FALSE@	    tests="test"; \
+@NATIVE_FALSE@	    All=""; \
+@NATIVE_FALSE@	  else \
+@NATIVE_FALSE@	    tests="tests"; \
+@NATIVE_FALSE@	    All="All "; \
+@NATIVE_FALSE@	  fi; \
+@NATIVE_FALSE@	  if test "$$failed" -eq 0; then \
+@NATIVE_FALSE@	    if test "$$xfail" -eq 0; then \
+@NATIVE_FALSE@	      banner="$$All$$all $$tests passed"; \
+@NATIVE_FALSE@	    else \
+@NATIVE_FALSE@	      if test "$$xfail" -eq 1; then failures=failure; else failures=failures; fi; \
+@NATIVE_FALSE@	      banner="$$All$$all $$tests behaved as expected ($$xfail expected $$failures)"; \
+@NATIVE_FALSE@	    fi; \
+@NATIVE_FALSE@	  else \
+@NATIVE_FALSE@	    if test "$$xpass" -eq 0; then \
+@NATIVE_FALSE@	      banner="$$failed of $$all $$tests failed"; \
+@NATIVE_FALSE@	    else \
+@NATIVE_FALSE@	      if test "$$xpass" -eq 1; then passes=pass; else passes=passes; fi; \
+@NATIVE_FALSE@	      banner="$$failed of $$all $$tests did not behave as expected ($$xpass unexpected $$passes)"; \
+@NATIVE_FALSE@	    fi; \
+@NATIVE_FALSE@	  fi; \
+@NATIVE_FALSE@	  dashes="$$banner"; \
+@NATIVE_FALSE@	  skipped=""; \
+@NATIVE_FALSE@	  if test "$$skip" -ne 0; then \
+@NATIVE_FALSE@	    if test "$$skip" -eq 1; then \
+@NATIVE_FALSE@	      skipped="($$skip test was not run)"; \
+@NATIVE_FALSE@	    else \
+@NATIVE_FALSE@	      skipped="($$skip tests were not run)"; \
+@NATIVE_FALSE@	    fi; \
+@NATIVE_FALSE@	    test `echo "$$skipped" | wc -c` -le `echo "$$banner" | wc -c` || \
+@NATIVE_FALSE@	      dashes="$$skipped"; \
+@NATIVE_FALSE@	  fi; \
+@NATIVE_FALSE@	  report=""; \
+@NATIVE_FALSE@	  if test "$$failed" -ne 0 && test -n "$(PACKAGE_BUGREPORT)"; then \
+@NATIVE_FALSE@	    report="Please report to $(PACKAGE_BUGREPORT)"; \
+@NATIVE_FALSE@	    test `echo "$$report" | wc -c` -le `echo "$$banner" | wc -c` || \
+@NATIVE_FALSE@	      dashes="$$report"; \
+@NATIVE_FALSE@	  fi; \
+@NATIVE_FALSE@	  dashes=`echo "$$dashes" | sed s/./=/g`; \
+@NATIVE_FALSE@	  if test "$$failed" -eq 0; then \
+@NATIVE_FALSE@	    col="$$grn"; \
+@NATIVE_FALSE@	  else \
+@NATIVE_FALSE@	    col="$$red"; \
+@NATIVE_FALSE@	  fi; \
+@NATIVE_FALSE@	  echo "$${col}$$dashes$${std}"; \
+@NATIVE_FALSE@	  echo "$${col}$$banner$${std}"; \
+@NATIVE_FALSE@	  test -z "$$skipped" || echo "$${col}$$skipped$${std}"; \
+@NATIVE_FALSE@	  test -z "$$report" || echo "$${col}$$report$${std}"; \
+@NATIVE_FALSE@	  echo "$${col}$$dashes$${std}"; \
+@NATIVE_FALSE@	  test "$$failed" -eq 0; \
+@NATIVE_FALSE@	else :; fi
 check-am: all-am
 	$(MAKE) $(AM_MAKEFLAGS) $(check_PROGRAMS)
 	$(MAKE) $(AM_MAKEFLAGS) check-TESTS
@@ -745,6 +803,141 @@ uninstall-am:
 	mostlyclean-multi pdf pdf-am ps ps-am tags uninstall \
 	uninstall-am
 
+
+@NATIVE_TRUE@check-TESTS: $(TESTS)
+@NATIVE_TRUE@	@failed=0; all=0; xfail=0; xpass=0; skip=0; \
+@NATIVE_TRUE@	srcdir=$(srcdir); export srcdir; \
+@NATIVE_TRUE@	list=' $(TESTS) '; \
+@NATIVE_TRUE@	$(am__tty_colors); \
+@NATIVE_TRUE@	if ! test -e glinktest.debug; then \
+@NATIVE_TRUE@	  $(OBJCOPY) --only-keep-debug glinktest glinktest.debug; \
+@NATIVE_TRUE@	  $(STRIP) glinktest; \
+@NATIVE_TRUE@	  $(OBJCOPY) --add-gnu-debuglink=glinktest.debug glinktest; \
+@NATIVE_TRUE@	fi; \
+@NATIVE_TRUE@	if ! test -e pictest.debug; then \
+@NATIVE_TRUE@	  $(OBJCOPY) --only-keep-debug pictest pictest.debug; \
+@NATIVE_TRUE@	  $(STRIP) pictest; \
+@NATIVE_TRUE@	  $(OBJCOPY) --add-gnu-debuglink=pictest.debug pictest; \
+@NATIVE_TRUE@	fi; \
+@NATIVE_TRUE@	if ! test -e .build-id; then \
+@NATIVE_TRUE@	  mkdir .build-id; \
+@NATIVE_TRUE@	  mkdir .build-id/01/; \
+@NATIVE_TRUE@	  mkdir temp; \
+@NATIVE_TRUE@	  $(OBJCOPY) --only-keep-debug bidtest bidtest.debug; \
+@NATIVE_TRUE@	  $(STRIP) bidtest; \
+@NATIVE_TRUE@	  touch temp; \
+@NATIVE_TRUE@	  mv bidtest.debug temp;\
+@NATIVE_TRUE@	  ln -s ../../temp/bidtest.debug .build-id/01/23456789abcdef0123456789abcdef01234567.debug; \
+@NATIVE_TRUE@	fi; \
+@NATIVE_TRUE@	if test -n "$$list"; then \
+@NATIVE_TRUE@	  for tst in $$list; do \
+@NATIVE_TRUE@	    if test -f ./$$tst; then dir=./; \
+@NATIVE_TRUE@	    elif test -f $$tst; then dir=; \
+@NATIVE_TRUE@	    else dir="$(srcdir)/"; fi; \
+@NATIVE_TRUE@	    if $(TESTS_ENVIRONMENT) $${dir}$$tst; then \
+@NATIVE_TRUE@	      all=`expr $$all + 1`; \
+@NATIVE_TRUE@	      case " $(XFAIL_TESTS) " in \
+@NATIVE_TRUE@	      *[\ \	]$$tst[\ \	]*) \
+@NATIVE_TRUE@		xpass=`expr $$xpass + 1`; \
+@NATIVE_TRUE@		failed=`expr $$failed + 1`; \
+@NATIVE_TRUE@		col=$$red; res=XPASS; \
+@NATIVE_TRUE@	      ;; \
+@NATIVE_TRUE@	      *) \
+@NATIVE_TRUE@		col=$$grn; res=PASS; \
+@NATIVE_TRUE@	      ;; \
+@NATIVE_TRUE@	      esac; \
+@NATIVE_TRUE@	    elif test $$? -ne 77; then \
+@NATIVE_TRUE@	      all=`expr $$all + 1`; \
+@NATIVE_TRUE@	      case " $(XFAIL_TESTS) " in \
+@NATIVE_TRUE@	      *[\ \	]$$tst[\ \	]*) \
+@NATIVE_TRUE@		xfail=`expr $$xfail + 1`; \
+@NATIVE_TRUE@		col=$$lgn; res=XFAIL; \
+@NATIVE_TRUE@	      ;; \
+@NATIVE_TRUE@	      *) \
+@NATIVE_TRUE@		failed=`expr $$failed + 1`; \
+@NATIVE_TRUE@		col=$$red; res=FAIL; \
+@NATIVE_TRUE@	      ;; \
+@NATIVE_TRUE@	      esac; \
+@NATIVE_TRUE@	    else \
+@NATIVE_TRUE@	      skip=`expr $$skip + 1`; \
+@NATIVE_TRUE@	      col=$$blu; res=SKIP; \
+@NATIVE_TRUE@	    fi; \
+@NATIVE_TRUE@	    echo "$${col}$$res$${std}: $$tst"; \
+@NATIVE_TRUE@	  done; \
+@NATIVE_TRUE@	  if test "$$all" -eq 1; then \
+@NATIVE_TRUE@	    tests="test"; \
+@NATIVE_TRUE@	    All=""; \
+@NATIVE_TRUE@	  else \
+@NATIVE_TRUE@	    tests="tests"; \
+@NATIVE_TRUE@	    All="All "; \
+@NATIVE_TRUE@	  fi; \
+@NATIVE_TRUE@	  if test "$$failed" -eq 0; then \
+@NATIVE_TRUE@	    if test "$$xfail" -eq 0; then \
+@NATIVE_TRUE@	      banner="$$All$$all $$tests passed"; \
+@NATIVE_TRUE@	    else \
+@NATIVE_TRUE@	      if test "$$xfail" -eq 1; then failures=failure; else failures=failures; fi; \
+@NATIVE_TRUE@	      banner="$$All$$all $$tests behaved as expected ($$xfail expected $$failures)"; \
+@NATIVE_TRUE@	    fi; \
+@NATIVE_TRUE@	  else \
+@NATIVE_TRUE@	    if test "$$xpass" -eq 0; then \
+@NATIVE_TRUE@	      banner="$$failed of $$all $$tests failed"; \
+@NATIVE_TRUE@	    else \
+@NATIVE_TRUE@	      if test "$$xpass" -eq 1; then passes=pass; else passes=passes; fi; \
+@NATIVE_TRUE@	      banner="$$failed of $$all $$tests did not behave as expected ($$xpass unexpected $$passes)"; \
+@NATIVE_TRUE@	    fi; \
+@NATIVE_TRUE@	  fi; \
+@NATIVE_TRUE@	  dashes="$$banner"; \
+@NATIVE_TRUE@	  skipped=""; \
+@NATIVE_TRUE@	  if test "$$skip" -ne 0; then \
+@NATIVE_TRUE@	    if test "$$skip" -eq 1; then \
+@NATIVE_TRUE@	      skipped="($$skip test was not run)"; \
+@NATIVE_TRUE@	    else \
+@NATIVE_TRUE@	      skipped="($$skip tests were not run)"; \
+@NATIVE_TRUE@	    fi; \
+@NATIVE_TRUE@	    test `echo "$$skipped" | wc -c` -le `echo "$$banner" | wc -c` || \
+@NATIVE_TRUE@	      dashes="$$skipped"; \
+@NATIVE_TRUE@	  fi; \
+@NATIVE_TRUE@	  report=""; \
+@NATIVE_TRUE@	  if test "$$failed" -ne 0 && test -n "$(PACKAGE_BUGREPORT)"; then \
+@NATIVE_TRUE@	    report="Please report to $(PACKAGE_BUGREPORT)"; \
+@NATIVE_TRUE@	    test `echo "$$report" | wc -c` -le `echo "$$banner" | wc -c` || \
+@NATIVE_TRUE@	      dashes="$$report"; \
+@NATIVE_TRUE@	  fi; \
+@NATIVE_TRUE@	  dashes=`echo "$$dashes" | sed s/./=/g`; \
+@NATIVE_TRUE@	  if test "$$failed" -eq 0; then \
+@NATIVE_TRUE@	    col="$$grn"; \
+@NATIVE_TRUE@	  else \
+@NATIVE_TRUE@	    col="$$red"; \
+@NATIVE_TRUE@	  fi; \
+@NATIVE_TRUE@	  echo "$${col}$$dashes$${std}"; \
+@NATIVE_TRUE@	  echo "$${col}$$banner$${std}"; \
+@NATIVE_TRUE@	  test -z "$$skipped" || echo "$${col}$$skipped$${std}"; \
+@NATIVE_TRUE@	  test -z "$$report" || echo "$${col}$$report$${std}"; \
+@NATIVE_TRUE@	  echo "$${col}$$dashes$${std}"; \
+@NATIVE_TRUE@	  test "$$failed" -eq 0; \
+@NATIVE_TRUE@	else :; fi
+
+@NATIVE_TRUE@clean-checkPROGRAMS:
+@NATIVE_TRUE@	@if test -e glinktest.debug; then \
+@NATIVE_TRUE@	 echo "rm -f glinktest.debug pictest.debug"; \
+@NATIVE_TRUE@	 rm -f glinktest.debug pictest.debug; \
+@NATIVE_TRUE@	fi; \
+@NATIVE_TRUE@	if test -d temp; then \
+@NATIVE_TRUE@	 echo "rm -rf temp"; \
+@NATIVE_TRUE@	 rm -rf temp; \
+@NATIVE_TRUE@	fi; \
+@NATIVE_TRUE@	if test -d .build-id; then \
+@NATIVE_TRUE@	  echo "rm -rf .build-id"; \
+@NATIVE_TRUE@	  rm -rf .build-id; \
+@NATIVE_TRUE@	fi; \
+@NATIVE_TRUE@	list='$(check_PROGRAMS)'; \
+@NATIVE_TRUE@	test -n "$$list" || exit 0; \
+@NATIVE_TRUE@	echo " rm -f" $$list; \
+@NATIVE_TRUE@	rm -f $$list || exit $$?; \
+@NATIVE_TRUE@	test -n "$(EXEEXT)" || exit 0; \
+@NATIVE_TRUE@	list=`for p in $$list; do echo "$$p"; done | sed 's/$(EXEEXT)$$//'`; \
+@NATIVE_TRUE@	echo " rm -f" $$list; \
+@NATIVE_TRUE@	rm -f $$list;
 alloc.lo: config.h backtrace.h internal.h
 backtrace.lo: config.h backtrace.h internal.h
 btest.lo: (INCDIR)/filenames.h backtrace.h backtrace-supported.h
diff --git a/libbacktrace/configure b/libbacktrace/configure
index 4e720e1..8910996 100755
--- a/libbacktrace/configure
+++ b/libbacktrace/configure
@@ -630,6 +630,7 @@ LD
 FGREP
 SED
 LIBTOOL
+OBJCOPY
 RANLIB
 MAINT
 MAINTAINER_MODE_FALSE
@@ -5011,6 +5012,44 @@ else
 fi
 
 
+# Extract the first word of "objcopy", so it can be a program name with args.
+set dummy objcopy; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if test "${ac_cv_prog_OBJCOPY+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$OBJCOPY"; then
+  ac_cv_prog_OBJCOPY="$OBJCOPY" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
+    ac_cv_prog_OBJCOPY="objcopy"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+fi
+fi
+OBJCOPY=$ac_cv_prog_OBJCOPY
+if test -n "$OBJCOPY"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $OBJCOPY" >&5
+$as_echo "$OBJCOPY" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+
 for ac_prog in gawk mawk nawk awk
 do
   # Extract the first word of "$ac_prog", so it can be a program name with args.
@@ -11131,7 +11170,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11134 "configure"
+#line 11173 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11237,7 +11276,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11240 "configure"
+#line 11279 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
diff --git a/libbacktrace/configure.ac b/libbacktrace/configure.ac
index 71e8518..bc4e688 100644
--- a/libbacktrace/configure.ac
+++ b/libbacktrace/configure.ac
@@ -74,6 +74,8 @@ AC_SUBST(CFLAGS)
 
 AC_PROG_RANLIB
 
+AC_CHECK_PROG(OBJCOPY, objcopy, objcopy)
+
 AC_PROG_AWK
 case "$AWK" in
 "") AC_MSG_ERROR([can't build without awk]) ;;
diff --git a/libbacktrace/crc32.c b/libbacktrace/crc32.c
new file mode 100644
index 0000000..f38a422
--- /dev/null
+++ b/libbacktrace/crc32.c
@@ -0,0 +1,107 @@
+/* crc32.c -- compute the CRC-32
+
+   The CRC-32 defined in IEEE 802.3 using the polynomial:
+
+   x32 + x26 + x23 + x22 + x16 + x12 + x11  + x10 + x8 + x7 + x5 + x4
+   + x2 + x + 1
+
+   Hexademical representation of the polynomial over GF(2): 0xedb88320
+
+   The table was generated by algorithm from zlib.(zlib/crc32.c)
+   The algorithm is described below.
+
+   * Copyright (C) 1995-2006, 2010, 2011, 2012, 2016 Mark Adler
+   * For conditions of distribution and use, see copyright notice in zlib.h
+
+   Polynomials over GF(2) are represented in binary, one bit per coefficient,
+   with the lowest powers in the most significant bit.  Then adding polynomials
+   is just exclusive-or, and multiplying a polynomial by x is a right shift by
+   one.
+
+   This calculation is done using the shift-register method of multiplying and
+   taking the remainder.  The register is initialized to zero, and for each
+   incoming bit, x^32 is added mod p to the register if the bit is a one (where
+   x^32 mod p is p+x^32 = x^26+...+1), and the register is multiplied mod p by
+   x (which is shifting right by one and adding x^32 mod p if the bit shifted
+   out is a one).  We start with the highest power (least significant bit) of
+   q and repeat for all eight bits of q.
+
+   unsigned long crc_table[256];
+   void make_crc_table()
+   {
+    unsigned long c;
+    int n, k;
+    unsigned long poly;
+    static const unsigned char p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26};
+
+    poly = 0;
+    for (n = 0; n < (int)(sizeof(p)/sizeof(unsigned char)); n++)
+        poly |= (unsigned long)1 << (31 - p[n]);
+
+    for (n = 0; n < 256; n++) {
+       c = (unsigned long)n;
+       for (k = 0; k < 8; k++)
+           c = c & 1 ? poly ^ (c >> 1) : c >> 1;
+       crc_table[n] = c;
+     }
+   }
+*/
+
+static const uint32_t crc32_table[256]
+  = {0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
+     0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
+     0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
+     0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+     0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
+     0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
+     0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
+     0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+     0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
+     0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+     0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
+     0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+     0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
+     0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
+     0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+     0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+     0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
+     0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
+     0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
+     0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+     0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
+     0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+     0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
+     0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+     0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
+     0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
+     0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
+     0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+     0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
+     0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+     0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
+     0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+     0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
+     0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+     0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+     0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+     0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
+     0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+     0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
+     0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+     0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
+     0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+     0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d};
+
+static uint32_t
+gnu_debuglink_crc32 (uint32_t crc, const unsigned char *buf, size_t len)
+{
+  const unsigned char *end;
+  end = buf + len;
+  crc = ~crc;
+  while (buf < end)
+    {
+      crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8);
+      ++buf;
+    }
+  return ~crc;
+}
diff --git a/libbacktrace/elf.c b/libbacktrace/elf.c
index 81ba344..ec68737 100644
--- a/libbacktrace/elf.c
+++ b/libbacktrace/elf.c
@@ -35,6 +35,9 @@ POSSIBILITY OF SUCH DAMAGE.  */
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
 
 #ifdef HAVE_DL_ITERATE_PHDR
 #include <link.h>
@@ -42,6 +45,24 @@ POSSIBILITY OF SUCH DAMAGE.  */
 
 #include "backtrace.h"
 #include "internal.h"
+#include "filenames.h"
+/* In case some other libraries build libbacktrace from source
+   (for example: libsanitizer does that way), we should manually update
+   each Makefile for each library to avoid situation with undefined
+   references after adding new file into libbacktrace sources.
+   Another way is to include crc32.c file into preproccessing stage.  */
+#include "crc32.c"
+
+#undef PATH_MAX
+#define PATH_MAX 4096
+
+#ifndef DIR_SEPARATOR
+#define DIR_SEPARATOR '/'
+#endif
+
+#ifndef HAVE_GETEXECNAME
+#define getexecname() NULL
+#endif
 
 #ifndef HAVE_DL_ITERATE_PHDR
 
@@ -283,6 +304,853 @@ struct elf_syminfo_data
   size_t count;
 };
 
+/* Information to read ELF note section.  */
+
+typedef struct
+{
+  unsigned char namesz[4];
+  unsigned char descsz[4];
+  unsigned char type[4];
+  unsigned char name[1];
+} Elf_External_Note;
+
+/* Information about type of the file.  */
+
+enum type_of_file
+{
+  FILE_TYPE_INVALID = -1,
+  FILE_TYPE_LINK = 1,
+  FILE_TYPE_REGULAR = 2
+};
+
+/* Information about debug paths.  */
+
+enum debug_path
+{
+  DEBUG_PATH_CURRENT,
+  DEBUG_PATH_CURRENT_DEBUG,
+  DEBUG_PATH_USR_LIB_DEBUG,
+  DEBUG_PATH_USR_LIB_DEBUG_PATH_TO_EXE,
+  DEBUG_PATH_MAX
+};
+
+/* Type of the ELF file.  */
+
+enum type_of_elf
+{
+  ELF_TYPE_DYN = -1,
+  ELF_TYPE_INVALID = 0,
+  ELF_TYPE_EXEC = 1
+};
+
+/* Paths to debug file.  */
+
+static const char *const debug_file_path[DEBUG_PATH_MAX]
+  = {"", ".debug/", "/usr/lib/debug/", "/usr/lib/debug"};
+
+/* Get a uint32 from the buffer.  */
+
+static uint32_t
+get_uint32 (const unsigned char *p, int is_bigendian)
+{
+  if (is_bigendian)
+    return (((uint32_t) p[0] << 24) | ((uint32_t) p[1] << 16)
+	    | ((uint32_t) p[2] << 8) | (uint32_t) p[3]);
+  else
+    return (((uint32_t) p[3] << 24) | ((uint32_t) p[2] << 16)
+	    | ((uint32_t) p[1] << 8) | (uint32_t) p[0]);
+}
+
+/* Generate crc32 sum from the file.  */
+
+static uint32_t
+get_crc32 (struct backtrace_state *state, int descriptor,
+	   backtrace_error_callback error_callback, void *data)
+{
+  uint32_t file_crc;
+  off_t offset;
+  size_t buffer_count;
+  size_t buffer_len;
+  size_t pass;
+  size_t out_of_buffer_len;
+  const unsigned char *buffer;
+  struct stat file_stat;
+  struct backtrace_view file_view;
+
+  buffer_len = 8 * 1024;
+  offset = 0;
+  file_crc = 0;
+  out_of_buffer_len = 0;
+
+  memset (&file_stat, 0, sizeof (struct stat));
+
+  if (fstat (descriptor, &file_stat) == -1)
+    {
+      if (errno != ENOENT)
+	error_callback (data, "fstat", errno);
+      return 0;
+    }
+
+  if (!backtrace_get_view (state, descriptor, offset, file_stat.st_size,
+			   error_callback, data, &file_view))
+    return 0;
+
+  buffer = (const unsigned char *) file_view.data;
+  buffer_count = file_stat.st_size / buffer_len;
+  out_of_buffer_len = file_stat.st_size % buffer_len;
+
+  for (pass = 0; pass < buffer_count; ++pass)
+    {
+      file_crc = gnu_debuglink_crc32 (file_crc, buffer + offset, buffer_len);
+      offset += buffer_len;
+    }
+
+  if (out_of_buffer_len)
+    file_crc
+      = gnu_debuglink_crc32 (file_crc, buffer + offset, out_of_buffer_len);
+
+  backtrace_release_view (state, &file_view, error_callback, data);
+  return file_crc;
+}
+
+/* Get length of the base name.  */
+
+static size_t
+base_name_len (const char *buffer)
+{
+  size_t len;
+
+  len = strlen (buffer);
+  while (len > 1 && !IS_DIR_SEPARATOR (buffer[len - 1]))
+    --len;
+  return len > 1 ? len : 0;
+}
+
+/* Verify crc32 sum.  */
+
+static unsigned int
+check_sum (struct backtrace_state *state, int descriptor,
+	   backtrace_error_callback error_callback, void *data,
+	   const unsigned char *debug_link, size_t offset, size_t section_size,
+	   int is_bigendian)
+{
+  uint32_t crc32_debug_link;
+  uint32_t crc32_debug_file;
+  offset += 1;
+  offset = (offset + 3) & ~3;
+  if (offset + 4 > section_size)
+    return 0;
+  crc32_debug_link = get_uint32 (debug_link + offset, is_bigendian);
+  crc32_debug_file = get_crc32 (state, descriptor, error_callback, data);
+  return crc32_debug_link == crc32_debug_file;
+}
+
+/* Process elf header. Verify magic number, version, etc, of the ELF
+   header. Populate ehdr_out, names_view_out and shdrs_view_out. Caller
+   should release view of the names_view_out and shdrs_view_out. Return
+   ELF_TYPE_EXEC if the file type is EXE, ELF_TYPE_DYN if type of the
+   file is DYN and ELF_TYPE_INVALID on the fail.  */
+
+static enum type_of_elf
+process_elf_header (struct backtrace_state *state, int descriptor,
+		    backtrace_error_callback error_callback, void *data,
+		    int exe, b_elf_ehdr *ehdr_out,
+		    struct backtrace_view *shdrs_view_out,
+		    struct backtrace_view *names_view_out)
+{
+  struct backtrace_view ehdr_view;
+  const b_elf_shdr *shstrhdr;
+  const b_elf_shdr *shdrs;
+  unsigned int shstrndx;
+  unsigned int shnum;
+  off_t shoff;
+  int shdrs_view_valid;
+
+  shdrs_view_valid = 0;
+
+  if (!backtrace_get_view (state, descriptor, 0, sizeof *ehdr_out,
+			   error_callback, data, &ehdr_view))
+    goto fail;
+
+  memcpy (ehdr_out, ehdr_view.data, sizeof *ehdr_out);
+
+  backtrace_release_view (state, &ehdr_view, error_callback, data);
+
+  if (ehdr_out->e_ident[EI_MAG0] != ELFMAG0
+      || ehdr_out->e_ident[EI_MAG1] != ELFMAG1
+      || ehdr_out->e_ident[EI_MAG2] != ELFMAG2
+      || ehdr_out->e_ident[EI_MAG3] != ELFMAG3)
+    {
+      error_callback (data, "processed file is not ELF", 0);
+      goto fail;
+    }
+  if (ehdr_out->e_ident[EI_VERSION] != EV_CURRENT)
+    {
+      error_callback (data, "processed file is unrecognized ELF version", 0);
+      goto fail;
+    }
+
+#if BACKTRACE_ELF_SIZE == 32
+#define BACKTRACE_ELFCLASS ELFCLASS32
+#else
+#define BACKTRACE_ELFCLASS ELFCLASS64
+#endif
+
+  if (ehdr_out->e_ident[EI_CLASS] != BACKTRACE_ELFCLASS)
+    {
+      error_callback (data, "processed file is unexpected ELF class", 0);
+      goto fail;
+    }
+
+  if (ehdr_out->e_ident[EI_DATA] != ELFDATA2LSB
+      && ehdr_out->e_ident[EI_DATA] != ELFDATA2MSB)
+    {
+      error_callback (data, "processed file has unknown endianness", 0);
+      goto fail;
+    }
+
+  /* If the executable is ET_DYN, it is either a PIE, or we are running
+     directly a shared library with .interp.  We need to wait for
+     dl_iterate_phdr in that case to determine the actual base_address.  */
+  if (exe && ehdr_out->e_type == ET_DYN)
+    return ELF_TYPE_DYN;
+
+  shoff = ehdr_out->e_shoff;
+  shnum = ehdr_out->e_shnum;
+  shstrndx = ehdr_out->e_shstrndx;
+
+  if ((shnum == 0 || shstrndx == SHN_XINDEX) && shoff != 0)
+    {
+      struct backtrace_view shdr_view;
+      const b_elf_shdr *shdr;
+
+      if (!backtrace_get_view (state, descriptor, shoff, sizeof (b_elf_shdr),
+			       error_callback, data, &shdr_view))
+	goto fail;
+
+      shdr = (const b_elf_shdr *) shdr_view.data;
+
+      if (shnum == 0)
+	shnum = shdr->sh_size;
+
+      if (shstrndx == SHN_XINDEX)
+	{
+	  shstrndx = shdr->sh_link;
+
+	  /* Versions of the GNU binutils between 2.12 and 2.18 did
+	     not handle objects with more than SHN_LORESERVE sections
+	     correctly.  All large section indexes were offset by
+	     0x100.  There is more information at
+	     http://sourceware.org/bugzilla/show_bug.cgi?id-5900 .
+	     Fortunately these object files are easy to detect, as the
+	     GNU binutils always put the section header string table
+	     near the end of the list of sections.  Thus if the
+	     section header string table index is larger than the
+	     number of sections, then we know we have to subtract
+	     0x100 to get the real section index.  */
+	  if (shstrndx >= shnum && shstrndx >= SHN_LORESERVE + 0x100)
+	    shstrndx -= 0x100;
+	}
+      backtrace_release_view (state, &shdr_view, error_callback, data);
+    }
+
+  /* Read the section headers, skipping the first one.  */
+
+  if (!backtrace_get_view (state, descriptor, shoff + sizeof (b_elf_shdr),
+			   (shnum - 1) * sizeof (b_elf_shdr), error_callback,
+			   data, shdrs_view_out))
+    goto fail;
+
+  shdrs_view_valid = 1;
+
+  shdrs = (const b_elf_shdr *) shdrs_view_out->data;
+  shstrhdr = &shdrs[shstrndx - 1];
+
+  /* Read the section names.  */
+
+  if (!backtrace_get_view (state, descriptor, shstrhdr->sh_offset,
+			   shstrhdr->sh_size, error_callback, data,
+			   names_view_out))
+    goto fail;
+
+  ehdr_out->e_shoff = shoff;
+  ehdr_out->e_shnum = shnum;
+  ehdr_out->e_shstrndx = shstrndx;
+
+  return ELF_TYPE_EXEC;
+
+ fail:
+  /* In case fail happens with backtrace_get_view for names section.  */
+  if (shdrs_view_valid)
+    backtrace_release_view (state, shdrs_view_out, error_callback, data);
+  return ELF_TYPE_INVALID;
+}
+
+/* Get content of the specifying section.  */
+
+static unsigned char *
+elf_get_section_by_name (struct backtrace_state *state, int descriptor,
+			 backtrace_error_callback error_callback, void *data,
+			 size_t *section_data_len_out, const char *section_name,
+			 b_elf_ehdr *ehdr, struct backtrace_view *shdrs_view,
+			 struct backtrace_view *names_view)
+{
+  const b_elf_shdr *shdrs;
+  const b_elf_shdr *shstrhdr;
+  size_t shstr_size;
+  struct backtrace_view section_view;
+  const char *names;
+  unsigned int i;
+  unsigned int shnum;
+  unsigned int shstrndx;
+  int section_view_valid;
+  unsigned char *section_data;
+
+  section_view_valid = 0;
+  section_data = NULL;
+
+  shnum = ehdr->e_shnum;
+  shstrndx = ehdr->e_shstrndx;
+  shdrs = (const b_elf_shdr *) shdrs_view->data;
+  shstrhdr = &shdrs[shstrndx - 1];
+  shstr_size = shstrhdr->sh_size;
+
+  names = (const char *) names_view->data;
+
+  for (i = 1; i < shnum; ++i)
+    {
+      const b_elf_shdr *shdr;
+      unsigned int sh_name;
+      const char *name;
+      shdr = &shdrs[i - 1];
+      sh_name = shdr->sh_name;
+      if (sh_name >= shstr_size)
+	{
+	  error_callback (data, "ELF section name out of range", 0);
+	  goto exit;
+	}
+
+      name = names + sh_name;
+
+      if (strcmp (name, section_name) == 0)
+	{
+	  if (backtrace_get_view (state, descriptor, shdr->sh_offset,
+				  shdr->sh_size, error_callback, data,
+				  &section_view))
+	    {
+	      section_view_valid = 1;
+	      section_data
+		= backtrace_alloc (state, shdr->sh_size, error_callback, data);
+	      if (section_data == NULL)
+		goto exit;
+	      memcpy (section_data, section_view.data, shdr->sh_size);
+	      *section_data_len_out = shdr->sh_size;
+	    }
+	  break;
+	}
+    }
+
+ exit:
+  if (section_view_valid)
+    backtrace_release_view (state, &section_view, error_callback, data);
+  return section_data;
+}
+
+/* Verify type of the file.  */
+
+static enum type_of_file
+backtrace_readlink (const char *filename,
+		    backtrace_error_callback error_callback, void *data)
+{
+  struct stat link_stat;
+  enum type_of_file file_type;
+  mode_t mode;
+
+  memset (&link_stat, 0, sizeof (struct stat));
+
+  if (lstat (filename, &link_stat) == -1)
+    {
+      if (errno != ENOENT)
+	error_callback (data, filename, errno);
+      file_type = FILE_TYPE_INVALID;
+    }
+
+  mode = link_stat.st_mode & S_IFMT;
+
+  switch (mode)
+    {
+    case S_IFLNK:
+      file_type = FILE_TYPE_LINK;
+      break;
+    case S_IFREG:
+      file_type = FILE_TYPE_REGULAR;
+      break;
+    default:
+      file_type = FILE_TYPE_INVALID;
+    }
+  return file_type;
+}
+
+/* Resolve full name of the link. In this case we can't use realpath function
+   because it could be undefined on some platfroms, also it allocates memory
+   by malloc, which we can't use.  */
+
+static ssize_t
+resolve_realname (const char *filename, char *buffer,
+		  struct backtrace_state *state,
+		  backtrace_error_callback error_callback, void *data)
+{
+  char *temp_buffer;
+  enum type_of_file file_type;
+  ssize_t filename_len;
+  size_t temp_filename_len;
+  size_t base_len;
+  int valid_temp_buffer;
+
+  valid_temp_buffer = 0;
+  filename_len = -1;
+  file_type = FILE_TYPE_LINK;
+
+  /* Allocate memory for sizeof(PATH_MAX) + 1 bytes because at this time
+     we don't know how long path could be.  */
+  temp_buffer = backtrace_alloc (state, PATH_MAX + 1, error_callback, data);
+  if (temp_buffer == NULL)
+    return -1;
+
+  valid_temp_buffer = 1;
+
+  memset (temp_buffer, 0, PATH_MAX + 1);
+  memcpy (temp_buffer, filename, strlen (filename));
+
+  while (file_type == FILE_TYPE_LINK)
+    {
+      filename_len = readlink (temp_buffer, buffer, PATH_MAX);
+      if (filename_len < 1)
+	goto exit;
+
+      temp_filename_len = strlen (buffer);
+
+      /* Full path.  */
+      if (IS_ABSOLUTE_PATH (buffer))
+	{
+	  memset (temp_buffer, 0, PATH_MAX);
+	  memcpy (temp_buffer, buffer, temp_filename_len);
+	}
+      else
+	{
+	  /* Relative path.  */
+	  base_len = base_name_len (temp_buffer);
+	  if (!base_len || (base_len + filename_len > PATH_MAX))
+	    {
+	      filename_len = -1;
+	      goto exit;
+	    }
+	  memcpy (temp_buffer + base_len, buffer, filename_len);
+	  temp_buffer[base_len + filename_len] = '\0';
+	}
+
+      file_type = backtrace_readlink (temp_buffer, error_callback, data);
+      memset (buffer, 0, filename_len);
+    }
+
+  if (file_type != FILE_TYPE_REGULAR)
+    {
+      filename_len = -1;
+      goto exit;
+    }
+
+  filename_len = strlen (temp_buffer);
+  memcpy (buffer, temp_buffer, filename_len);
+
+ exit:
+  if (valid_temp_buffer)
+    backtrace_free (state, temp_buffer, PATH_MAX + 1, error_callback, data);
+  return filename_len;
+}
+
+/* Resolve realname of the filename. This function verifies filename.
+   If filename is name of the file it populates realname buffer.
+   If filename is link, it calls resolve_realname function.  */
+
+static unsigned int
+backtrace_resolve_realname (const char *filename, char *realname,
+			    struct backtrace_state *state,
+			    backtrace_error_callback error_callback, void *data)
+{
+  enum type_of_file file_type;
+  ssize_t filename_len;
+
+  filename_len = -1;
+
+  file_type = backtrace_readlink (filename, error_callback, data);
+
+  if (file_type == FILE_TYPE_LINK)
+    {
+      /* Read the actual filename.  */
+      filename_len
+	= resolve_realname (filename, realname, state, error_callback, data);
+      if (filename_len < 1)
+	return 0;
+    }
+  else if (file_type == FILE_TYPE_REGULAR)
+    {
+      filename_len = strlen (filename);
+      if (filename_len > PATH_MAX)
+	return 0;
+      memcpy (realname, filename, filename_len);
+    }
+  /* FILE_TYPE_INVALID.  */
+  else
+    return 0;
+
+  return 1;
+}
+
+/* Search for debug file into specifying directorires.  */
+
+static int
+search_for_debugfile (char *realname, char *debug_filename,
+		      backtrace_error_callback error_callback, void *data,
+		      struct backtrace_state *state)
+{
+  size_t debug_filename_len;
+  size_t pass;
+  size_t debug_path_len;
+  size_t buffer_len;
+  size_t base_len;
+  int debug_does_not_exist;
+  int debug_descriptor;
+  int valid_buffer;
+  char *buffer;
+
+  debug_descriptor = -1;
+  valid_buffer = 0;
+
+  base_len = base_name_len (realname);
+
+  if (!base_len)
+    return debug_descriptor;
+
+  debug_filename_len = strlen ((const char *) debug_filename);
+
+  if (!debug_filename_len)
+    return debug_descriptor;
+
+  buffer_len = base_len + strlen (debug_file_path[DEBUG_PATH_USR_LIB_DEBUG])
+	       + debug_filename_len + 1;
+
+  buffer = backtrace_alloc (state, buffer_len, error_callback, data);
+
+  if (buffer == NULL)
+    return debug_descriptor;
+
+  valid_buffer = 1;
+
+  memset (buffer, 0, buffer_len);
+  memcpy (buffer, realname, base_len);
+
+  for (pass = 0; pass < DEBUG_PATH_MAX; ++pass)
+    {
+      switch (pass)
+	{
+	case DEBUG_PATH_CURRENT:
+	  {
+	    memcpy (buffer + base_len, debug_filename, debug_filename_len);
+	    break;
+	  }
+	case DEBUG_PATH_CURRENT_DEBUG:
+	  {
+	    debug_path_len = strlen (debug_file_path[DEBUG_PATH_CURRENT_DEBUG]);
+	    memcpy (buffer + base_len,
+		    debug_file_path[DEBUG_PATH_CURRENT_DEBUG], debug_path_len);
+	    memcpy (buffer + base_len + debug_path_len, debug_filename,
+		    debug_filename_len);
+	    break;
+	  }
+	case DEBUG_PATH_USR_LIB_DEBUG:
+	  {
+	    debug_path_len = strlen (debug_file_path[DEBUG_PATH_USR_LIB_DEBUG]);
+	    memset (buffer, 0, buffer_len);
+	    memcpy (buffer, debug_file_path[DEBUG_PATH_USR_LIB_DEBUG],
+		    debug_path_len);
+	    memcpy (buffer + debug_path_len, debug_filename,
+		    debug_filename_len);
+	    break;
+	  }
+	case DEBUG_PATH_USR_LIB_DEBUG_PATH_TO_EXE:
+	  {
+	    debug_path_len
+	      = strlen (debug_file_path[DEBUG_PATH_USR_LIB_DEBUG_PATH_TO_EXE]);
+	    memset (buffer, 0, buffer_len);
+	    memcpy (buffer,
+		    debug_file_path[DEBUG_PATH_USR_LIB_DEBUG_PATH_TO_EXE],
+		    debug_path_len);
+	    memcpy (buffer + debug_path_len, realname, base_len);
+	    memcpy (buffer + debug_path_len + base_len, debug_filename,
+		    debug_filename_len);
+	    break;
+	  }
+	default:
+	  goto exit;
+	}
+
+      debug_descriptor
+	= backtrace_open (buffer, error_callback, data, &debug_does_not_exist);
+
+      if (debug_descriptor >= 0)
+	break;
+    }
+
+ exit:
+  if (valid_buffer)
+    backtrace_free (state, buffer, buffer_len, error_callback, data);
+  return debug_descriptor;
+}
+
+/* Open debug file by gnulink.  */
+
+static int
+open_debugfile_by_gnulink (char *realname, unsigned char *section_data,
+			   size_t section_data_len, int is_bigendian,
+			   struct backtrace_state *state,
+			   backtrace_error_callback error_callback, void *data)
+{
+  int debug_descriptor;
+
+  debug_descriptor = search_for_debugfile (realname, (char *) section_data,
+					   error_callback, data, state);
+  if (debug_descriptor < 0)
+    return -1;
+
+  /* Check the crc32 checksum if it is not the same return -1.  */
+
+  if (!check_sum (state, debug_descriptor, error_callback, data,
+		  (const unsigned char *) section_data,
+		  strlen ((char *) section_data), section_data_len,
+		  is_bigendian))
+    {
+      /* If crc32 sums are different, just close the descriptor
+	 associated with debuginfo file.  */
+      backtrace_close (debug_descriptor, error_callback, data);
+      debug_descriptor = -1;
+    }
+
+  return debug_descriptor;
+}
+
+/* Convert char to hex */
+
+static char
+hex (char ch)
+{
+  return ch > 9 ? ('a' + (ch - 10)) : ('0' + ch);
+}
+
+/* Get build-id name.  */
+
+static char *
+get_build_id_name (unsigned char *section_data, size_t *len,
+		   int is_bigendian, struct backtrace_state *state,
+		   backtrace_error_callback error_callback, void *data)
+{
+  Elf_External_Note *build_id_section;
+  char *build_id_name;
+  char *temp;
+  const char *debug_postfix;
+  const char *debug_prefix;
+  size_t debug_postfix_len;
+  size_t debug_prefix_len;
+  size_t name_size;
+  size_t offset;
+  unsigned char *hash_start;
+  uint32_t hash_size;
+  uint32_t identifier;
+
+  debug_postfix_len = 6;
+  debug_prefix_len = 10;
+  debug_postfix = ".debug";
+  debug_prefix = ".build-id/";
+
+  build_id_section = (Elf_External_Note *) section_data;
+  hash_size = get_uint32 (build_id_section->descsz, is_bigendian);
+  identifier = get_uint32 (build_id_section->type, is_bigendian);
+  name_size = get_uint32 (build_id_section->namesz, is_bigendian);
+
+  if (identifier != NT_GNU_BUILD_ID || hash_size == 0 || name_size != 4
+      || strncmp ((char *) build_id_section->name, "GNU", 3) != 0)
+    return NULL;
+
+  offset = 16;
+  hash_start = section_data + offset;
+  *len = hash_size * 2 + debug_postfix_len + debug_prefix_len + 1;
+  build_id_name = backtrace_alloc (state, *len, error_callback, data);
+
+  if (build_id_name == NULL)
+    {
+      *len = 0;
+      return NULL;
+    }
+
+  memset (build_id_name, 0, *len);
+  memcpy (build_id_name, debug_prefix, debug_prefix_len);
+  temp = build_id_name + debug_prefix_len;
+
+  *temp++ = hex ((*hash_start & 0xF0) >> 4);
+  *temp++ = hex (*hash_start & 0x0F);
+  ++hash_start;
+  --hash_size;
+  *temp++ = DIR_SEPARATOR;
+
+  while (hash_size--)
+    {
+      *temp++ = hex ((*hash_start & 0xF0) >> 4);
+      *temp++ = hex (*hash_start & 0x0F);
+      ++hash_start;
+    }
+
+  memcpy (temp, debug_postfix, debug_postfix_len);
+  return build_id_name;
+}
+
+/* Open file by build-id.  */
+
+static int
+open_debugfile_by_build_id (char *realname, unsigned char *section_data,
+			    int is_bigendian, struct backtrace_state *state,
+			    backtrace_error_callback error_callback, void *data)
+
+{
+  char *build_id_name;
+  int debug_descriptor;
+  size_t build_id_name_len;
+  int valid_build_id_name;
+
+  debug_descriptor = -1;
+  valid_build_id_name = 0;
+  build_id_name_len = 0;
+
+  build_id_name = get_build_id_name (section_data, &build_id_name_len,
+				     is_bigendian, state, error_callback, data);
+
+  if (!build_id_name_len)
+    return -1;
+
+  valid_build_id_name = 1;
+
+  debug_descriptor = search_for_debugfile (realname, build_id_name,
+					   error_callback, data, state);
+
+  if (valid_build_id_name)
+    backtrace_free (state, build_id_name, build_id_name_len, error_callback,
+		    data);
+  return debug_descriptor;
+}
+
+/* Open debug file.  */
+
+static int
+backtrace_open_debugfile (int descriptor, const char *filename,
+			  backtrace_error_callback error_callback, void *data,
+			  struct backtrace_state *state)
+{
+  int debug_descriptor;
+  unsigned char *gnulink_section_data;
+  unsigned char *build_id_section_data;
+  int valid_descriptor;
+  int valid_gnulink_section_data;
+  int valid_build_id_section_data;
+  int valid_realname;
+  int valid_elf_header;
+  size_t build_id_section_data_len;
+  size_t gnu_link_section_data_len;
+  char *realname;
+  b_elf_ehdr ehdr;
+  struct backtrace_view shdrs_view;
+  struct backtrace_view names_view;
+
+  valid_elf_header = 0;
+  valid_realname = 0;
+  valid_descriptor = 0;
+  valid_gnulink_section_data = 0;
+  valid_build_id_section_data = 0;
+  build_id_section_data_len = 0;
+  gnu_link_section_data_len = 0;
+  debug_descriptor = -1;
+
+  if (!process_elf_header (state, descriptor, error_callback, data, 0, &ehdr,
+			   &shdrs_view, &names_view))
+    return -1;
+
+  valid_elf_header = 1;
+
+  realname = backtrace_alloc (state, PATH_MAX + 1, error_callback, data);
+
+  if (realname == NULL)
+    goto exit;
+
+  /* Indicates that we successfully allocated memory.  */
+  valid_realname = 1;
+
+  /* Populate the buffer with realname.  */
+  if (!backtrace_resolve_realname (filename, realname, state, error_callback,
+				   data))
+    goto exit;
+
+  /* Check if build-id section does exist.  */
+  build_id_section_data
+    = elf_get_section_by_name (state, descriptor, error_callback, data,
+			       &build_id_section_data_len, ".note.gnu.build-id",
+			       &ehdr, &shdrs_view, &names_view);
+
+  if (build_id_section_data_len)
+    {
+      valid_build_id_section_data = 1;
+      debug_descriptor
+	= open_debugfile_by_build_id (realname, build_id_section_data,
+				      ehdr.e_ident[EI_DATA] == ELFDATA2MSB,
+				      state, error_callback, data);
+    }
+
+  if (debug_descriptor < 0)
+    {
+      gnulink_section_data
+	= elf_get_section_by_name (state, descriptor, error_callback, data,
+				   &gnu_link_section_data_len, ".gnu_debuglink",
+				   &ehdr, &shdrs_view, &names_view);
+
+      if (gnu_link_section_data_len)
+	{
+	  valid_gnulink_section_data = 1;
+	  debug_descriptor
+	    = open_debugfile_by_gnulink (realname, gnulink_section_data,
+					 gnu_link_section_data_len,
+					 ehdr.e_ident[EI_DATA] == ELFDATA2MSB,
+					 state, error_callback, data);
+	}
+    }
+
+  if (debug_descriptor >= 0)
+    valid_descriptor = 1;
+
+ exit:
+  if (valid_descriptor)
+    backtrace_close (descriptor, error_callback, data);
+  if (valid_gnulink_section_data)
+    backtrace_free (state, gnulink_section_data, gnu_link_section_data_len,
+		    error_callback, data);
+  if (valid_build_id_section_data)
+    backtrace_free (state, build_id_section_data, build_id_section_data_len,
+		    error_callback, data);
+  if (valid_realname)
+    backtrace_free (state, realname, PATH_MAX + 1, error_callback, data);
+  if (valid_elf_header)
+    {
+      backtrace_release_view (state, &names_view, error_callback, data);
+      backtrace_release_view (state, &shdrs_view, error_callback, data);
+    }
+  return debug_descriptor;
+}
+
 /* A dummy callback function used when we can't find any debug info.  */
 
 static int
@@ -521,9 +1389,7 @@ elf_add (struct backtrace_state *state, int descriptor, uintptr_t base_address,
 	 backtrace_error_callback error_callback, void *data,
 	 fileline *fileline_fn, int *found_sym, int *found_dwarf, int exe)
 {
-  struct backtrace_view ehdr_view;
   b_elf_ehdr ehdr;
-  off_t shoff;
   unsigned int shnum;
   unsigned int shstrndx;
   struct backtrace_view shdrs_view;
@@ -531,7 +1397,6 @@ elf_add (struct backtrace_state *state, int descriptor, uintptr_t base_address,
   const b_elf_shdr *shdrs;
   const b_elf_shdr *shstrhdr;
   size_t shstr_size;
-  off_t shstr_off;
   struct backtrace_view names_view;
   int names_view_valid;
   const char *names;
@@ -547,6 +1412,7 @@ elf_add (struct backtrace_state *state, int descriptor, uintptr_t base_address,
   off_t max_offset;
   struct backtrace_view debug_view;
   int debug_view_valid;
+  enum type_of_elf elf_type;
 
   *found_sym = 0;
   *found_dwarf = 0;
@@ -557,116 +1423,32 @@ elf_add (struct backtrace_state *state, int descriptor, uintptr_t base_address,
   strtab_view_valid = 0;
   debug_view_valid = 0;
 
-  if (!backtrace_get_view (state, descriptor, 0, sizeof ehdr, error_callback,
-			   data, &ehdr_view))
-    goto fail;
-
-  memcpy (&ehdr, ehdr_view.data, sizeof ehdr);
-
-  backtrace_release_view (state, &ehdr_view, error_callback, data);
-
-  if (ehdr.e_ident[EI_MAG0] != ELFMAG0
-      || ehdr.e_ident[EI_MAG1] != ELFMAG1
-      || ehdr.e_ident[EI_MAG2] != ELFMAG2
-      || ehdr.e_ident[EI_MAG3] != ELFMAG3)
-    {
-      error_callback (data, "executable file is not ELF", 0);
-      goto fail;
-    }
-  if (ehdr.e_ident[EI_VERSION] != EV_CURRENT)
-    {
-      error_callback (data, "executable file is unrecognized ELF version", 0);
-      goto fail;
-    }
-
-#if BACKTRACE_ELF_SIZE == 32
-#define BACKTRACE_ELFCLASS ELFCLASS32
-#else
-#define BACKTRACE_ELFCLASS ELFCLASS64
-#endif
-
-  if (ehdr.e_ident[EI_CLASS] != BACKTRACE_ELFCLASS)
+  elf_type = process_elf_header (state, descriptor, error_callback, data, exe,
+				 &ehdr, &shdrs_view, &names_view);
+  switch (elf_type)
     {
-      error_callback (data, "executable file is unexpected ELF class", 0);
+    /* Binary compiled with PIE option.  */
+    case ELF_TYPE_DYN:
+      return -1;
+    case ELF_TYPE_EXEC:
+      break;
+    /* Header is invalid.  */
+    case ELF_TYPE_INVALID:
       goto fail;
     }
 
-  if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB
-      && ehdr.e_ident[EI_DATA] != ELFDATA2MSB)
-    {
-      error_callback (data, "executable file has unknown endianness", 0);
-      goto fail;
-    }
-
-  /* If the executable is ET_DYN, it is either a PIE, or we are running
-     directly a shared library with .interp.  We need to wait for
-     dl_iterate_phdr in that case to determine the actual base_address.  */
-  if (exe && ehdr.e_type == ET_DYN)
-    return -1;
-
-  shoff = ehdr.e_shoff;
-  shnum = ehdr.e_shnum;
-  shstrndx = ehdr.e_shstrndx;
-
-  if ((shnum == 0 || shstrndx == SHN_XINDEX)
-      && shoff != 0)
-    {
-      struct backtrace_view shdr_view;
-      const b_elf_shdr *shdr;
-
-      if (!backtrace_get_view (state, descriptor, shoff, sizeof shdr,
-			       error_callback, data, &shdr_view))
-	goto fail;
-
-      shdr = (const b_elf_shdr *) shdr_view.data;
-
-      if (shnum == 0)
-	shnum = shdr->sh_size;
-
-      if (shstrndx == SHN_XINDEX)
-	{
-	  shstrndx = shdr->sh_link;
-
-	  /* Versions of the GNU binutils between 2.12 and 2.18 did
-	     not handle objects with more than SHN_LORESERVE sections
-	     correctly.  All large section indexes were offset by
-	     0x100.  There is more information at
-	     http://sourceware.org/bugzilla/show_bug.cgi?id-5900 .
-	     Fortunately these object files are easy to detect, as the
-	     GNU binutils always put the section header string table
-	     near the end of the list of sections.  Thus if the
-	     section header string table index is larger than the
-	     number of sections, then we know we have to subtract
-	     0x100 to get the real section index.  */
-	  if (shstrndx >= shnum && shstrndx >= SHN_LORESERVE + 0x100)
-	    shstrndx -= 0x100;
-	}
-
-      backtrace_release_view (state, &shdr_view, error_callback, data);
-    }
+  shdrs_view_valid = 1;
+  names_view_valid = 1;
 
   /* To translate PC to file/line when using DWARF, we need to find
      the .debug_info and .debug_line sections.  */
 
-  /* Read the section headers, skipping the first one.  */
-
-  if (!backtrace_get_view (state, descriptor, shoff + sizeof (b_elf_shdr),
-			   (shnum - 1) * sizeof (b_elf_shdr),
-			   error_callback, data, &shdrs_view))
-    goto fail;
-  shdrs_view_valid = 1;
   shdrs = (const b_elf_shdr *) shdrs_view.data;
 
-  /* Read the section names.  */
-
+  shnum = ehdr.e_shnum;
+  shstrndx = ehdr.e_shstrndx;
   shstrhdr = &shdrs[shstrndx - 1];
   shstr_size = shstrhdr->sh_size;
-  shstr_off = shstrhdr->sh_offset;
-
-  if (!backtrace_get_view (state, descriptor, shstr_off, shstr_size,
-			   error_callback, data, &names_view))
-    goto fail;
-  names_view_valid = 1;
   names = (const char *) names_view.data;
 
   symtab_shndx = 0;
@@ -877,6 +1659,7 @@ phdr_callback (struct dl_phdr_info *info, size_t size ATTRIBUTE_UNUSED,
   int does_not_exist;
   fileline elf_fileline_fn;
   int found_dwarf;
+  int debug_descriptor;
 
   /* There is not much we can do if we don't have the module name,
      unless executable is ET_DYN, where we expect the very first
@@ -895,11 +1678,19 @@ phdr_callback (struct dl_phdr_info *info, size_t size ATTRIBUTE_UNUSED,
 	  backtrace_close (pd->exe_descriptor, pd->error_callback, pd->data);
 	  pd->exe_descriptor = -1;
 	}
+      debug_descriptor = -1;
 
       descriptor = backtrace_open (info->dlpi_name, pd->error_callback,
 				   pd->data, &does_not_exist);
+
       if (descriptor < 0)
 	return 0;
+
+      debug_descriptor
+	= backtrace_open_debugfile (descriptor, info->dlpi_name,
+				    pd->error_callback, pd->data, pd->state);
+      if (debug_descriptor >= 0)
+	descriptor = debug_descriptor;
     }
 
   if (elf_add (pd->state, descriptor, info->dlpi_addr, pd->error_callback,
@@ -915,6 +1706,53 @@ phdr_callback (struct dl_phdr_info *info, size_t size ATTRIBUTE_UNUSED,
   return 0;
 }
 
+/* On succcess returns pathname of the executable. On fail returns NULL.  */
+static const char *
+get_exec_filename (backtrace_error_callback error_callback, void *data)
+{
+  int descriptor;
+  const char *filename;
+  unsigned int pass;
+
+  descriptor = -1;
+  filename = NULL;
+
+  for (pass = 0; pass < 4; ++pass)
+    {
+      int does_not_exist;
+
+      switch (pass)
+	{
+	case 0:
+	  filename = getexecname ();
+	  break;
+	case 1:
+	  filename = "/proc/self/exe";
+	  break;
+	case 2:
+	  filename = "/proc/curproc/file";
+	  break;
+	default:
+	  filename = NULL;
+	  break;
+	}
+
+      if (filename == NULL)
+	continue;
+
+      descriptor
+	= backtrace_open (filename, error_callback, data, &does_not_exist);
+
+      if (descriptor >= 0)
+	break;
+    }
+
+  if (descriptor >= 0)
+    backtrace_close (descriptor, error_callback, data);
+
+  return filename;
+}
+
 /* Initialize the backtrace data we need from an ELF executable.  At
    the ELF level, all we need to do is find the debug info
    sections.  */
@@ -929,6 +1767,24 @@ backtrace_initialize (struct backtrace_state *state, int descriptor,
   int found_dwarf;
   fileline elf_fileline_fn = elf_nodebug;
   struct phdr_data pd;
+  int debug_descriptor;
+  const char *filename;
+
+  debug_descriptor = -1;
+
+  /* In case state->filename is not initialized, we should resolve the
+     executable name, because that name is needed to find the path to
+     the file with debug info. So to avoid changing API for
+     backtrace_initalize we can do it with some overhead by iterating
+     through all possible names and trying to open the file.  */
+  filename = state->filename == NULL ? get_exec_filename (error_callback, data)
+				     : state->filename;
+
+  if (filename != NULL)
+    debug_descriptor = backtrace_open_debugfile (descriptor, filename,
+						 error_callback, data, state);
+  if (debug_descriptor >= 0)
+    descriptor = debug_descriptor;
 
   ret = elf_add (state, descriptor, 0, error_callback, data, &elf_fileline_fn,
 		 &found_sym, &found_dwarf, 1);