[Bug bootstrap/61899] gcc/Makefile.in: compile failure occasionally while parallel make enabled

["hongxu.jia at windriver dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61899

--- Comment #2 from hongxu jia <hongxu.jia at windriver dot com> ---
The previous fix is incorrect, it caused other build failure.
Here is the new solution:

The gcc-ar.o, gcc-nm.o, gcc-ranlib.o and errors.o included
config.h which was a generated file. But no explicity rule
to clarify the dependency. There was potential building
failure while parallel make.

For gcc-ar.o, gcc-nm.o and gcc-ranlib.o, they were compiled from one C
source file gcc-ar.c, we add them to ALL_HOST_BACKEND_OBJS, so the
'$(ALL_HOST_OBJS) : | $(generated_files)' rule could work for these
objects.

For errors.o, it is part of gengtype, and the gengtype generator program
is special: Two versions are built. One is for the build machine, and one
is for the host. We refered what gengtype-parse.o did (which also is part
of gengtype).

Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
---
 gcc/Makefile.in | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index a726109..cdaa406 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -1491,13 +1491,16 @@ OBJS-libcommon-target = $(common_out_object_file)
prefix.o params.o \
     opts.o opts-common.o options.o vec.o hooks.o common/common-targhooks.o \
     hash-table.o file-find.o

+# Objects compiled from one C source file gcc-ar.c
+OBJS-gcc-ar = gcc-ar.o gcc-nm.o gcc-ranlib.o
+
 # This lists all host objects for the front ends.
 ALL_HOST_FRONTEND_OBJS = $(foreach v,$(CONFIG_LANGUAGES),$($(v)_OBJS))

 ALL_HOST_BACKEND_OBJS = $(GCC_OBJS) $(OBJS) $(OBJS-libcommon) \
   $(OBJS-libcommon-target) @TREEBROWSER@ main.o c-family/cppspec.o \
   $(COLLECT2_OBJS) $(EXTRA_GCC_OBJS) $(GCOV_OBJS) $(GCOV_DUMP_OBJS) \
-  $(GCOV_TOOL_OBJS) lto-wrapper.o collect-utils.o
+  $(GCOV_TOOL_OBJS) lto-wrapper.o collect-utils.o $(OBJS-gcc-ar)

 # This lists all host object files, whether they are included in this
 # compilation or not.
@@ -2447,6 +2450,8 @@ gengtype-lex.o: $(CONFIG_H) $(BCONFIG_H)
 CFLAGS-gengtype-lex.o += -DGENERATOR_FILE
 build/gengtype-lex.o: $(BCONFIG_H)

+errors.o : $(CONFIG_H)
+
 gengtype-parse.o build/gengtype-parse.o : gengtype-parse.c gengtype.h \
   $(SYSTEM_H)
 gengtype-parse.o: $(CONFIG_H)