http://sourceware.org/ml/gdb-patches/2012-01/msg00170.html
Subject: [patch 2/2] Fix linking on non-x86* after libgdb.a removal

Hi,

this is the second part for solving corelow after the s390x regression:
	[patch 2/2] Do not build libgdb.a by default
	http://sourceware.org/ml/gdb-patches/2011-12/msg00716.html
->
	corelow.o:(.bss+0x0): multiple definition of `core_gdbarch'
	corelow.o:(.bss+0x0): first defined here
	corelow.o: In function `deprecated_add_core_fns':
	corelow.c:(.text+0x0): multiple definition of `deprecated_add_core_fns'
	corelow.o:corelow.c:(.text+0x0): first defined here


For targets using new set_gdbarch_regset_from_core_section it would not be
a problem, just put corelow.o into the right entry of gdb/configure.tgt.

But for legacy targets still using deprecated_add_core_fns (like
sparc-solaris2.6 etc.) the addition to gdb/configure.tgt would enable
corelow.o even for cross-targeted GDBs where there is unfortunately still no
core files support.

Created the original configuration, just avoiding a duplicate corelow.o entry.
A better idea is welcome.

(s390x not available now for a test but it should work I hope.)


Sorry,
Jan


2012-01-04  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Fix duplicate .o files after omitting libbfd.a.
	* Makefile.in (CORELOW_O): New definition.
	(ALL_TARGET_OBS): Remove corelow.o.
	(DEPFILES): Add $(CORELOW_O).
	* config/alpha/alpha-linux.mh (NATDEPFILES): Remove corelow.o.
	(CORELOW_O): New definition.
	* config/alpha/alpha-osf3.mh: Likewise.
	* config/alpha/fbsd.mh: Likewise.
	* config/arm/nbsdaout.mh: Likewise.
	* config/arm/nbsdelf.mh: Likewise.
	* config/i386/i386gnu.mh: Likewise.
	* config/ia64/hpux.mh: Likewise.
	* config/ia64/linux.mh: Likewise.
	* config/m32r/linux.mh: Likewise.
	* config/m68k/linux.mh: Likewise.
	* config/mips/irix5.mh: Likewise.
	* config/mips/irix6.mh: Likewise.
	* config/pa/hpux.mh: Likewise.
	* config/pa/linux.mh: Likewise.
	* config/powerpc/aix.mh: Likewise.
	* config/s390/s390.mh: Likewise.
	* config/sparc/linux.mh: Likewise.
	* config/sparc/linux64.mh: Likewise.
	* config/sparc/sol2.mh: Likewise.
	* config/vax/vax.mh: Likewise.
	* configure: Regenerate.
	* configure.ac (CORELOW_O): New variable.
	(gdb_target_obs): Exclude corelow.o and set CORELOW_O instead.
	(all_targets): Set CORELOW_O.
	(CORELOW_O): AC_SUBST it.

--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -512,6 +512,12 @@ SIM_OBS = @SIM_OBS@
 # Target-dependent object files.
 TARGET_OBS = @TARGET_OBS@
 
+# corelow.o may be requested by either config/*/*.mh file or for ALL_TARGET_OBS
+# or for specific target(s) from configure.tgt.  Avoid duplicating it.
+# CORELOW_O may get overriden (set to corelow.o) by 'host_makefile_frag' below.
+# CORELOW_O is assumed to be corelow.o for ALL_TARGET_OBS.
+CORELOW_O := @CORELOW_O@
+
 # All target-dependent objects files that require 64-bit CORE_ADDR
 # (used with --enable-targets=all --enable-64-bit-bfd).
 ALL_64_TARGET_OBS = \
@@ -581,7 +587,6 @@ ALL_TARGET_OBS = \
 	remote-m32r-sdi.o remote-mips.o \
 	xcoffread.o \
 	symfile-mem.o \
-	corelow.o \
 	windows-tdep.o \
 	linux-record.o
 
@@ -843,7 +848,7 @@ REMOTE_EXAMPLES = m68k-stub.c i386-stub.c sparc-stub.c rem-multi.shar
 # variables analogous to SER_HARDWIRE which get defaulted in this
 # Makefile.in
 
-DEPFILES = $(TARGET_OBS) $(SER_HARDWIRE) $(NATDEPFILES) \
+DEPFILES = $(TARGET_OBS) $(SER_HARDWIRE) $(NATDEPFILES) $(CORELOW_O) \
 	   $(REMOTE_OBS) $(SIM_OBS)
 
 SOURCES = $(SFILES) $(ALLDEPFILES) $(YYFILES) $(CONFIG_SRCS)
--- a/gdb/config/alpha/alpha-linux.mh
+++ b/gdb/config/alpha/alpha-linux.mh
@@ -1,8 +1,9 @@
 # Host: Little-endian Alpha running Linux
 NAT_FILE= config/nm-linux.h
-NATDEPFILES= inf-ptrace.o corelow.o alpha-linux-nat.o \
+NATDEPFILES= inf-ptrace.o alpha-linux-nat.o \
 	fork-child.o proc-service.o linux-thread-db.o \
 	linux-nat.o linux-osdata.o linux-fork.o linux-procfs.o
+CORELOW_O := corelow.o
 NAT_CDEPS = $(srcdir)/proc-service.list
 
 # The dynamically loaded libthread_db needs access to symbols in the
--- a/gdb/config/alpha/alpha-osf3.mh
+++ b/gdb/config/alpha/alpha-osf3.mh
@@ -1,6 +1,7 @@
 # Host: Little-endian Alpha running OSF/1-3.x and higher using procfs
 NAT_FILE= nm-osf3.h
-NATDEPFILES= corelow.o alpha-nat.o fork-child.o \
+NATDEPFILES= alpha-nat.o fork-child.o \
 	solib-osf.o procfs.o proc-api.o proc-events.o proc-flags.o \
 	proc-why.o dec-thread.o
+CORELOW_O := corelow.o
 NAT_CLIBS= -lpthreaddebug
--- a/gdb/config/alpha/fbsd.mh
+++ b/gdb/config/alpha/fbsd.mh
@@ -1,6 +1,7 @@
 # Host: FreeBSD/alpha
 NATDEPFILES= fork-child.o inf-ptrace.o \
 	fbsd-nat.o alphabsd-nat.o bsd-kvm.o \
-	corelow.o core-regset.o
+	core-regset.o
+CORELOW_O := corelow.o
 
 LOADLIBES= -lkvm
--- a/gdb/config/arm/nbsdaout.mh
+++ b/gdb/config/arm/nbsdaout.mh
@@ -1,3 +1,4 @@
 # Host: NetBSD/arm
-NATDEPFILES= fork-child.o inf-ptrace.o corelow.o armnbsd-nat.o \
+NATDEPFILES= fork-child.o inf-ptrace.o armnbsd-nat.o \
 	solib-sunos.o
+CORELOW_O := corelow.o
--- a/gdb/config/arm/nbsdelf.mh
+++ b/gdb/config/arm/nbsdelf.mh
@@ -1,2 +1,3 @@
 # Host: NetBSD/arm
-NATDEPFILES= fork-child.o inf-ptrace.o corelow.o armnbsd-nat.o
+NATDEPFILES= fork-child.o inf-ptrace.o armnbsd-nat.o
+CORELOW_O := corelow.o
--- a/gdb/config/i386/i386gnu.mh
+++ b/gdb/config/i386/i386gnu.mh
@@ -1,7 +1,8 @@
 # Host: Intel 386 running the GNU Hurd
-NATDEPFILES= i386gnu-nat.o gnu-nat.o corelow.o core-regset.o fork-child.o \
+NATDEPFILES= i386gnu-nat.o gnu-nat.o core-regset.o fork-child.o \
 	     notify_S.o process_reply_S.o msg_reply_S.o \
 	     msg_U.o exc_request_U.o exc_request_S.o
+CORELOW_O := corelow.o
 
 NAT_FILE= nm-i386gnu.h
 MH_CFLAGS = -D_GNU_SOURCE
--- a/gdb/config/ia64/hpux.mh
+++ b/gdb/config/ia64/hpux.mh
@@ -1,3 +1,4 @@
 # Host: ia64 running HP-UX
-NATDEPFILES= fork-child.o inf-ttrace.o corelow.o ia64-hpux-nat.o \
+NATDEPFILES= fork-child.o inf-ttrace.o ia64-hpux-nat.o \
         solib-ia64-hpux.o
+CORELOW_O := corelow.o
--- a/gdb/config/ia64/linux.mh
+++ b/gdb/config/ia64/linux.mh
@@ -1,11 +1,12 @@
 # Host: Intel IA-64 running GNU/Linux
 
 NAT_FILE= config/nm-linux.h
-NATDEPFILES= inf-ptrace.o fork-child.o corelow.o \
+NATDEPFILES= inf-ptrace.o fork-child.o \
 	core-regset.o ia64-linux-nat.o \
 	proc-service.o linux-thread-db.o \
 	linux-nat.o linux-osdata.o linux-fork.o \
 	linux-procfs.o
+CORELOW_O := corelow.o
 NAT_CDEPS = $(srcdir)/proc-service.list
 
 LOADLIBES = -ldl $(RDYNAMIC)
--- a/gdb/config/m32r/linux.mh
+++ b/gdb/config/m32r/linux.mh
@@ -1,9 +1,10 @@
 # Host: M32R based machine running GNU/Linux
 
 NAT_FILE= config/nm-linux.h
-NATDEPFILES= inf-ptrace.o fork-child.o corelow.o	\
+NATDEPFILES= inf-ptrace.o fork-child.o				\
 	m32r-linux-nat.o proc-service.o linux-thread-db.o	\
 	linux-nat.o linux-osdata.o linux-fork.o linux-procfs.o
+CORELOW_O := corelow.o
 NAT_CDEPS = $(srcdir)/proc-service.list
 
 LOADLIBES= -ldl $(RDYNAMIC)
--- a/gdb/config/m68k/linux.mh
+++ b/gdb/config/m68k/linux.mh
@@ -2,9 +2,10 @@
 
 NAT_FILE= config/nm-linux.h
 NATDEPFILES= inf-ptrace.o fork-child.o \
-	corelow.o m68klinux-nat.o \
+	m68klinux-nat.o \
 	proc-service.o linux-thread-db.o \
 	linux-nat.o linux-osdata.o linux-fork.o linux-procfs.o
+CORELOW_O := corelow.o
 NAT_CDEPS = $(srcdir)/proc-service.list
 
 # The dynamically loaded libthread_db needs access to symbols in the
--- a/gdb/config/mips/irix5.mh
+++ b/gdb/config/mips/irix5.mh
@@ -1,3 +1,4 @@
 # Host: SGI Iris running irix 5.x
-NATDEPFILES= fork-child.o irix5-nat.o corelow.o procfs.o \
+NATDEPFILES= fork-child.o irix5-nat.o procfs.o \
 	proc-api.o proc-events.o proc-flags.o proc-why.o
+CORELOW_O := corelow.o
--- a/gdb/config/mips/irix6.mh
+++ b/gdb/config/mips/irix6.mh
@@ -1,3 +1,4 @@
 # Host: SGI Iris running irix 6.x
-NATDEPFILES= fork-child.o irix5-nat.o corelow.o procfs.o \
+NATDEPFILES= fork-child.o irix5-nat.o procfs.o \
 	proc-api.o proc-events.o proc-flags.o proc-why.o
+CORELOW_O := corelow.o
--- a/gdb/config/pa/hpux.mh
+++ b/gdb/config/pa/hpux.mh
@@ -1,3 +1,4 @@
 # Host: PA-RISC HP-UX
 NATDEPFILES= fork-child.o inf-ptrace.o inf-ttrace.o \
-	hppa-hpux-nat.o corelow.o somread.o
+	hppa-hpux-nat.o somread.o
+CORELOW_O := corelow.o
--- a/gdb/config/pa/linux.mh
+++ b/gdb/config/pa/linux.mh
@@ -1,9 +1,10 @@
 # Host: Hewlett-Packard PA-RISC machine, running Linux
 NAT_FILE= config/nm-linux.h
-NATDEPFILES= inf-ptrace.o fork-child.o corelow.o \
+NATDEPFILES= inf-ptrace.o fork-child.o \
 	hppa-linux-nat.o proc-service.o linux-thread-db.o \
 	linux-nat.o linux-osdata.o linux-fork.o \
 	linux-procfs.o
+CORELOW_O := corelow.o
 NAT_CDEPS = $(srcdir)/proc-service.list
 
 LOADLIBES = -ldl $(RDYNAMIC)
--- a/gdb/config/powerpc/aix.mh
+++ b/gdb/config/powerpc/aix.mh
@@ -3,8 +3,9 @@
 NAT_FILE= config/rs6000/nm-rs6000.h
 
 # aix-thread.o is not listed in NATDEPFILES as it is pulled in by configure.
-NATDEPFILES= fork-child.o inf-ptrace.o corelow.o rs6000-nat.o \
+NATDEPFILES= fork-child.o inf-ptrace.o rs6000-nat.o \
 	     xcoffsolib.o
+CORELOW_O := corelow.o
 
 # When compiled with cc, for debugging, this argument should be passed.
 # We have no idea who our current compiler is though, so we skip it.
--- a/gdb/config/s390/s390.mh
+++ b/gdb/config/s390/s390.mh
@@ -1,7 +1,8 @@
 # Host: S390, running Linux
 NAT_FILE= config/nm-linux.h
-NATDEPFILES= inf-ptrace.o fork-child.o corelow.o s390-nat.o \
+NATDEPFILES= inf-ptrace.o fork-child.o s390-nat.o \
 	linux-thread-db.o proc-service.o \
 	linux-nat.o linux-osdata.o linux-fork.o linux-procfs.o
+CORELOW_O := corelow.o
 NAT_CDEPS = $(srcdir)/proc-service.list
 LOADLIBES = -ldl $(RDYNAMIC)
--- a/gdb/config/sparc/linux.mh
+++ b/gdb/config/sparc/linux.mh
@@ -1,10 +1,11 @@
 # Host: GNU/Linux SPARC
 NAT_FILE= config/nm-linux.h
 NATDEPFILES= sparc-nat.o sparc-linux-nat.o \
-	corelow.o core-regset.o fork-child.o inf-ptrace.o \
+	core-regset.o fork-child.o inf-ptrace.o \
 	proc-service.o linux-thread-db.o \
 	linux-nat.o linux-osdata.o linux-fork.o \
 	linux-procfs.o
+CORELOW_O := corelow.o
 NAT_CDEPS = $(srcdir)/proc-service.list
 
 # The dynamically loaded libthread_db needs access to symbols in the
--- a/gdb/config/sparc/linux64.mh
+++ b/gdb/config/sparc/linux64.mh
@@ -1,11 +1,12 @@
 # Host: GNU/Linux UltraSPARC
 NAT_FILE= config/nm-linux.h
 NATDEPFILES= sparc-nat.o sparc64-nat.o sparc64-linux-nat.o \
-	corelow.o core-regset.o \
+	core-regset.o \
 	fork-child.o inf-ptrace.o \
 	proc-service.o linux-thread-db.o \
 	linux-nat.o linux-osdata.o linux-fork.o \
 	linux-procfs.o
+CORELOW_O := corelow.o
 NAT_CDEPS = $(srcdir)/proc-service.list
 
 # The dynamically loaded libthread_db needs access to symbols in the
--- a/gdb/config/sparc/sol2.mh
+++ b/gdb/config/sparc/sol2.mh
@@ -1,5 +1,6 @@
 # Host: Solaris SPARC & UltraSPARC
 NAT_FILE= nm-sol2.h
 NATDEPFILES= sparc-sol2-nat.o \
-	corelow.o core-regset.o fork-child.o \
+	core-regset.o fork-child.o \
 	procfs.o proc-api.o proc-events.o proc-flags.o proc-why.o
+CORELOW_O := corelow.o
--- a/gdb/config/vax/vax.mh
+++ b/gdb/config/vax/vax.mh
@@ -1,2 +1,3 @@
 # Host: VAX running 4.2BSD or Ultrix
-NATDEPFILES= vax-nat.o fork-child.o inf-ptrace.o corelow.o
+NATDEPFILES= vax-nat.o fork-child.o inf-ptrace.o
+CORELOW_O := corelow.o
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -174,6 +174,7 @@ fi
 # Accumulate some settings from configure.tgt over all enabled targets
 
 TARGET_OBS=
+CORELOW_O=
 all_targets=
 
 for targ_alias in `echo $target_alias $enable_targets | sed 's/,/ /g'`
@@ -196,12 +197,16 @@ do
 
     # Target-specific object files
     for i in ${gdb_target_obs}; do
-        case " $TARGET_OBS " in
-        *" ${i} "*) ;;
-        *)
-          TARGET_OBS="$TARGET_OBS ${i}"
-          ;;
-        esac
+        if test "$i" = corelow.o; then
+            CORELOW_O=corelow.o
+        else
+            case " $TARGET_OBS " in
+            *" ${i} "*) ;;
+            *)
+              TARGET_OBS="$TARGET_OBS ${i}"
+              ;;
+            esac
+        fi
     done
 
     # Check whether this target needs 64-bit CORE_ADDR
@@ -233,9 +238,11 @@ if test x${all_targets} = xtrue; then
   else
     TARGET_OBS='$(ALL_TARGET_OBS)'
   fi
+  CORELOW_O=corelow.o
 fi
 
 AC_SUBST(TARGET_OBS)
+AC_SUBST(CORELOW_O)
 
 # For other settings, only the main target counts.
 gdb_sim=