buildsys: clean up libubacktrace linker script handling

Currently, the installed libubacktrace linker script entry always uses
HARDWIRED_ABSPATH semantics, even if HARDWIRED_ABSPATH is disabled:

    $ grep GROUP $PREFIX/mipsel-linux-uclibc/sys-root/usr/lib/libc.so
    GROUP ( libc.so.0 uclibc_nonshared.a AS_NEEDED ( ld-uClibc.so.0 ) )
    GROUP ( AS_NEEDED ( /lib/libubacktrace.so.0 ) )

This causes problems when building a non-sysroot toolchain.

Move the AS_NEEDED insertion into libc/Makefile.in, and add a case to
the HARDWIRED_ABSPATH substitution command so libubacktrace is handled
the same way as the other libraries listed in the script.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

Makefile.in

@@ -341,18 +341,13 @@ ifeq ($(HARDWIRED_ABSPATH),y)
 		$(SED) -e 's:$(NONSHARED_LIBNAME):$(DEVEL_PREFIX)$(MULTILIB_DIR)/$(NONSHARED_LIBNAME):' \
 		    -e 's:$(SHARED_LIBNAME):$(RUNTIME_PREFIX)$(MULTILIB_DIR)/$(SHARED_LIBNAME):' \
 		    -e 's:$(UCLIBC_LDSO):$(RUNTIME_PREFIX)$(MULTILIB_DIR)/$(UCLIBC_LDSO):' \
+		    -e 's:$(UBACKTRACE_DSO):$(RUNTIME_PREFIX)$(MULTILIB_DIR)/$(UBACKTRACE_DSO):' \
 		    $(top_builddir)lib/libc.so > $(PREFIX)$(DEVEL_PREFIX)$(MULTILIB_DIR)/libc.so; \
 		$(SED) -i -e 's://:/:g' $(PREFIX)$(DEVEL_PREFIX)$(MULTILIB_DIR)/libc.so; \
 	fi
 else
 	-$(INSTALL) -m 755 $(top_builddir)lib/libc.so $(PREFIX)$(DEVEL_PREFIX)$(MULTILIB_DIR)/
 endif
-ifeq ($(UCLIBC_HAS_BACKTRACE),y)
-# Add the AS_NEEDED entry for libubacktrace.so
-	if [ -f $(top_builddir)lib/libc.so -a -f $(PREFIX)$(RUNTIME_PREFIX)$(MULTILIB_DIR)/$(SHARED_LIBNAME) ] ; then \
-		echo "GROUP ( $(UBACKTRACE_ASNEEDED) )" >> $(PREFIX)$(DEVEL_PREFIX)$(MULTILIB_DIR)/libc.so; \
-	fi
-endif
 ifeq ($(UCLIBC_HAS_THREADS),y)
 ifneq ($(LINUXTHREADS_OLD),y)
 ifeq ($(HARDWIRED_ABSPATH),y)

Rules.mak

@@ -575,10 +575,12 @@ link.asneeded = $(if $(findstring yy,$(CC_FLAG_ASNEEDED)$(CC_FLAG_NO_ASNEEDED)),
 # Check for AS_NEEDED support in linker script (binutils>=2.16.1 has it)
 ifndef ASNEEDED
 export ASNEEDED:=$(shell $(LD) --help 2>/dev/null | grep -q -- --as-needed && echo "AS_NEEDED ( $(UCLIBC_LDSO) )" || echo "$(UCLIBC_LDSO)")
-ifeq ($(UCLIBC_HAS_BACKTRACE),y)
+
 # Only used in installed libc.so linker script
-UBACKTRACE_FULL_NAME := $(RUNTIME_PREFIX)lib/$(UBACKTRACE_DSO)
-export UBACKTRACE_ASNEEDED:=$(shell $(LD) --help 2>/dev/null | grep -q -- --as-needed && echo "AS_NEEDED ( $(UBACKTRACE_FULL_NAME) )" || echo "$(UBACKTRACE_FULL_NAME)")
+ifeq ($(UCLIBC_HAS_BACKTRACE),y)
+export UBACKTRACE_ASNEEDED:=$(shell $(LD) --help 2>/dev/null | grep -q -- --as-needed && \
+	echo "GROUP ( AS_NEEDED ( $(UBACKTRACE_DSO) ) )" || \
+	echo "GROUP ( $(UBACKTRACE_DSO) )")
 else
 export UBACKTRACE_ASNEEDED:=""
 endif

libc/Makefile.in

@@ -74,6 +74,7 @@ ifeq ($(COMPAT_ATEXIT),y)
 else
 	$(Q)echo "GROUP ( $(SHARED_LIBNAME) $(NONSHARED_LIBNAME) $(ASNEEDED) )" >> $@.tmp
 endif
+	$(Q)echo "$(UBACKTRACE_ASNEEDED)" >> $@.tmp
 	$(Q)mv $@.tmp $@
 
 $(libc_OUT)/libc_so.a: $(libc-so-y) | $(top_builddir)lib/libc.a $(top_builddir)lib/$(NONSHARED_LIBNAME)