Look for libfts and libobstack during configure, these
libraries are external to libc when using musl, whereas
on glibc these libraries are provided in libc itself.

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Upstream-Status: Inappropriate [workaround for musl]
--- a/configure.ac
+++ b/configure.ac
@@ -494,6 +494,60 @@ else
 fi
 AC_SUBST([argp_LDADD])
 
+dnl Check if we have fts available from our libc
+AC_LINK_IFELSE(
+	[AC_LANG_PROGRAM(
+		[#if !defined(__x86_64__)
+		#undef  _FILE_OFFSET_BITS
+		#define _FILE_OFFSET_BITS 32
+		#endif
+		#include <fts.h>],
+		[FTS* fts = 0; return fts_close(fts); return 0;]
+		)],
+	[libc_has_fts="true"],
+	[libc_has_fts="false"]
+)
+
+dnl If our libc doesn't provide fts, then test for libfts
+if test "$libc_has_fts" = "false" ; then
+	AC_MSG_WARN("libc does not have fts")
+	AC_CHECK_LIB([fts], [fts_close], [have_fts="true"], [have_fts="false"])
+
+	if test "$have_fts" = "false"; then
+		AC_MSG_ERROR("no libfts found")
+	else
+		fts_LDADD="-lfts"
+	fi
+else
+	fts_LDADD=""
+fi
+AC_SUBST([fts_LDADD])
+
+dnl Check if we have obstack available from our libc
+AC_LINK_IFELSE(
+	[AC_LANG_PROGRAM(
+		[#include <obstack.h>],
+		[_obstack_begin(0, 0, 0, NULL, NULL); return 0;]
+		)],
+	[libc_has_obstack="true"],
+	[libc_has_obstack="false"]
+)
+
+dnl If our libc doesn't provide obstack, then test for libobstack
+if test "$libc_has_obstack" = "false" ; then
+	AC_MSG_WARN("libc does not have obstack")
+	AC_CHECK_LIB([obstack], [_obstack_begin], [have_obstack="true"], [have_obstack="false"])
+
+	if test "$have_obstack" = "false"; then
+		AC_MSG_ERROR("no libobstack found")
+	else
+		obstack_LDADD="-lobstack"
+	fi
+else
+	obstack_LDADD=""
+fi
+AC_SUBST([obstack_LDADD])
+
 dnl The directories with content.
 
 dnl Documentation.
--- a/libdw/Makefile.am
+++ b/libdw/Makefile.am
@@ -108,7 +108,7 @@ am_libdw_pic_a_OBJECTS = $(libdw_a_SOURC
 libdw_so_LIBS = libdw_pic.a ../libdwelf/libdwelf_pic.a \
 	  ../libdwfl/libdwfl_pic.a ../libebl/libebl.a
 libdw_so_DEPS = ../lib/libeu.a ../libelf/libelf.so
-libdw_so_LDLIBS = $(libdw_so_DEPS) -ldl -lz $(argp_LDADD) $(zip_LIBS)
+libdw_so_LDLIBS = $(libdw_so_DEPS) -ldl -lz $(argp_LDADD) $(fts_LDADD) $(zip_LIBS)
 libdw_so_SOURCES =
 libdw.so$(EXEEXT): $(srcdir)/libdw.map $(libdw_so_LIBS) $(libdw_so_DEPS)
 # The rpath is necessary for libebl because its $ORIGIN use will
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -68,8 +68,8 @@ ar_no_Wstack_usage = yes
 unstrip_no_Wstack_usage = yes
 
 readelf_LDADD = $(libdw) $(libebl) $(libelf) $(libeu) $(argp_LDADD) -ldl
-nm_LDADD = $(libdw) $(libebl) $(libelf) $(libeu) $(argp_LDADD) -ldl \
-	   $(demanglelib)
+nm_LDADD = $(libdw) $(libebl) $(libelf) $(libeu) $(argp_LDADD) \
+	   $(obstack_LDADD) -ldl $(demanglelib)
 size_LDADD = $(libelf) $(libeu) $(argp_LDADD)
 strip_LDADD = $(libebl) $(libelf) $(libdw) $(libeu) $(argp_LDADD) -ldl
 elflint_LDADD  = $(libebl) $(libelf) $(libeu) $(argp_LDADD) -ldl
@@ -77,9 +77,9 @@ findtextrel_LDADD = $(libdw) $(libelf) $
 addr2line_LDADD = $(libdw) $(libelf) $(libeu) $(argp_LDADD) $(demanglelib)
 elfcmp_LDADD = $(libebl) $(libelf) $(libeu) $(argp_LDADD) -ldl
 objdump_LDADD  = $(libasm) $(libebl) $(libelf) $(libeu) $(argp_LDADD) -ldl
-ranlib_LDADD = libar.a $(libelf) $(libeu) $(argp_LDADD)
+ranlib_LDADD = libar.a $(libelf) $(libeu) $(argp_LDADD) $(obstack_LDADD)
 strings_LDADD = $(libelf) $(libeu) $(argp_LDADD)
-ar_LDADD = libar.a $(libelf) $(libeu) $(argp_LDADD)
+ar_LDADD = libar.a $(libelf) $(libeu) $(argp_LDADD) $(obstack_LDADD)
 unstrip_LDADD = $(libebl) $(libelf) $(libdw) $(libeu) $(argp_LDADD) -ldl
 stack_LDADD = $(libebl) $(libelf) $(libdw) $(libeu) $(argp_LDADD) -ldl $(demanglelib)
 elfcompress_LDADD = $(libebl) $(libelf) $(libdw) $(libeu) $(argp_LDADD)