[gcc r12-1257] For obj-c stage-final re-use the checksum from the previous stage

[gcc r12-1257] For obj-c stage-final re-use the checksum from the previous stage

[Bernd Edlinger]

https://gcc.gnu.org/g:3e00f8ddb729913831e494f87207b658292e6c2b

commit r12-1257-g3e00f8ddb729913831e494f87207b658292e6c2b
Author: Bernd Edlinger <bernd.edlinger@hotmail.de>
Date:   Fri May 28 06:54:13 2021 +0200

    For obj-c stage-final re-use the checksum from the previous stage
    
    This silences the stage compare.
    
    gcc/objc:
    2021-06-07  Bernd Edlinger  <bernd.edlinger@softing.com>
    
            * Make-lang.in (cc1obj-checksum.c): For stage-final re-use
            the checksum from the previous stage.
    
    gcc/objcp:
    2021-06-07  Bernd Edlinger  <bernd.edlinger@softing.com>
    
            * Make-lang.in (cc1objplus-checksum.c): For stage-final re-use
            the checksum from the previous stage.

Diff:
---
 gcc/objc/Make-lang.in  | 14 +++++++++++---
 gcc/objcp/Make-lang.in | 15 +++++++++++----
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/gcc/objc/Make-lang.in b/gcc/objc/Make-lang.in
index c91148a578e..901114066d5 100644
--- a/gcc/objc/Make-lang.in
+++ b/gcc/objc/Make-lang.in
@@ -57,11 +57,19 @@ OBJC_OBJS = objc/objc-lang.o objc/objc-act.o hash-table.o \
 
 objc_OBJS = $(OBJC_OBJS) cc1obj-checksum.o
 
+# compute checksum over all object files and the options
+# re-use the checksum from the prev-final stage so it passes
+# the bootstrap comparison and allows comparing of the cc1 binary
 cc1obj-checksum.c : build/genchecksum$(build_exeext) checksum-options \
         $(OBJC_OBJS) $(C_AND_OBJC_OBJS) $(BACKEND) $(LIBDEPS)
-	build/genchecksum$(build_exeext) $(OBJC_OBJS) $(C_AND_OBJC_OBJS) \
-        $(BACKEND) $(LIBDEPS) checksum-options > cc1obj-checksum.c.tmp && \
-	$(srcdir)/../move-if-change cc1obj-checksum.c.tmp cc1obj-checksum.c
+	if [ -f ../stage_final ] \
+	   && cmp -s ../stage_current ../stage_final; then \
+	  cp ../prev-gcc/$@ $@; \
+	else \
+	  build/genchecksum$(build_exeext) $(OBJC_OBJS) $(C_AND_OBJC_OBJS) \
+		$(BACKEND) $(LIBDEPS) checksum-options > $@.tmp && \
+	  $(srcdir)/../move-if-change $@.tmp $@; \
+	fi
 
 cc1obj$(exeext): $(OBJC_OBJS) $(C_AND_OBJC_OBJS) cc1obj-checksum.o $(BACKEND) \
 		 $(LIBDEPS) $(objc.prev)
diff --git a/gcc/objcp/Make-lang.in b/gcc/objcp/Make-lang.in
index dfa4d230eac..3ecc50b53bd 100644
--- a/gcc/objcp/Make-lang.in
+++ b/gcc/objcp/Make-lang.in
@@ -60,12 +60,19 @@ OBJCXX_OBJS = objcp/objcp-act.o objcp/objcp-lang.o objcp/objcp-decl.o \
 
 obj-c++_OBJS = $(OBJCXX_OBJS) cc1objplus-checksum.o
 
+# compute checksum over all object files and the options
+# re-use the checksum from the prev-final stage so it passes
+# the bootstrap comparison and allows comparing of the cc1 binary
 cc1objplus-checksum.c : build/genchecksum$(build_exeext) checksum-options \
 	$(OBJCXX_OBJS) $(BACKEND) $(CODYLIB) $(LIBDEPS)
-	build/genchecksum$(build_exeext) $(OBJCXX_OBJS) $(BACKEND) $(CODYLIB) \
-		$(LIBDEPS) checksum-options > cc1objplus-checksum.c.tmp && \
-	$(srcdir)/../move-if-change cc1objplus-checksum.c.tmp \
-	cc1objplus-checksum.c
+	if [ -f ../stage_final ] \
+	   && cmp -s ../stage_current ../stage_final; then \
+	  cp ../prev-gcc/$@ $@; \
+	else \
+	  build/genchecksum$(build_exeext) $(OBJCXX_OBJS) $(BACKEND) \
+		$(CODYLIB) $(LIBDEPS) checksum-options > $@.tmp && \
+	  $(srcdir)/../move-if-change $@.tmp $@; \
+	fi
 
 cc1objplus$(exeext): $(OBJCXX_OBJS) cc1objplus-checksum.o $(BACKEND) \
 		     $(CODYLIB) $(LIBDEPS) $(obj-c++.prev)