[PATCH 1/1] tools/build: Let link command read option from file

[<changqing.li@windriver.com>]

From: Changqing Li <changqing.li@windriver.com>

ld_multi will link multiple objects, when there are many objects, and
O=[absolute_path] is set, and the absolute_path is relatively long. It
is possile that this line "$(call if_changed,$(host)ld_multi)" will
report error:
"make[4]: /bin/sh: Argument list too long"

So make the ld command read option from file to fix above error. In
order to convenient debug, write the file content in dot-target.cmd
as comments.

Signed-off-by: Changqing Li <changqing.li@windriver.com>
---
 tools/build/Makefile.build | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tools/build/Makefile.build b/tools/build/Makefile.build
index 3584ff308607..e57ce8c34685 100644
--- a/tools/build/Makefile.build
+++ b/tools/build/Makefile.build
@@ -70,11 +70,13 @@ quiet_cmd_gen = GEN     $@
 # If there's nothing to link, create empty $@ object.
 quiet_cmd_ld_multi = LD      $@
       cmd_ld_multi = $(if $(strip $(obj-y)),\
-                     $(LD) -r -o $@  $(filter $(obj-y),$^),rm -f $@; $(AR) rcs $@)
+                     $(LD) -r -o $@ @$@.in,rm -f $@; $(AR) rcs $@)
 
 quiet_cmd_host_ld_multi = HOSTLD  $@
       cmd_host_ld_multi = $(if $(strip $(obj-y)),\
-                          $(HOSTLD) -r -o $@  $(filter $(obj-y),$^),rm -f $@; $(HOSTAR) rcs $@)
+                          $(HOSTLD) -r -o $@ @$@.in,rm -f $@; $(HOSTAR) rcs $@)
+
+output_ld_multi_dotin = $(if $(quiet),,@printf "# %s:\n# " $@.in >> $(dot-target).cmd;cat $@.in >> $(dot-target).cmd)
 
 ifneq ($(filter $(obj),$(hostprogs)),)
   host = host_
@@ -145,7 +147,10 @@ $(sort $(subdir-obj-y)): $(subdir-y) ;
 
 $(in-target): $(obj-y) $(test-y) FORCE
 	$(call rule_mkdir)
+	$(file >$@.in,$(filter $(obj-y),$^))
 	$(call if_changed,$(host)ld_multi)
+	$(if $(strip $(any-prereq) $(arg-check)), $(output_ld_multi_dotin))
+	@rm $@.in
 
 __build: $(in-target)
 	@:
-- 
2.34.1