configury: Fix up --enable-link-serialization support

Eric reported that the --enable-link-serialization changes seemed to
cause the binaries to be always relinked, for example from the
gcc/ directory of the build tree:
make
[relink of gnat1, brig1, cc1plus, d21, f951, go1, lto1, ...]
make
[relink of gnat1, brig1, cc1plus, d21, f951, go1, lto1, ...]
Furthermore as reported in PR, it can cause problems during make install
where make install rebuilds the binaries again.

The problem is that for make .PHONY targets are just
"rebuilt" always, so it is very much undesirable for the cc1plus$(exeext)
etc. dependencies to include .PHONY targets, but I was using
them - cc1plus.prev which would depend on some *.serial and
e.g. cc1.serial depending on c and c depending on cc1$(exeext).

The following patch rewrites this so that *.serial and *.prev aren't
.PHONY targets, but instead just make variables.

I was worried that the order in which the language makefile fragments are
included (which is quite random, what order we get from the filesystem
matching */config-lang.in) would be a problem but it seems to work fine
- as it uses make = rather than := variables, later definitions are just
fine for earlier uses as long as the uses aren't needed during the
makefile parsing, but only in the dependencies of make targets and in
their commands.

2020-11-20  Jakub Jelinek  <jakub@redhat.com>

	PR other/97911
gcc/
	* configure.ac: In SERIAL_LIST use lang words without .serial
	suffix.  Change $lang.prev from a target to variable and instead
	of depending on *.serial expand to the *.serial variable if
	the word is in the SERIAL_LIST at all, otherwise to nothing.
	* configure: Regenerated.
gcc/c/
	* Make-lang.in (c.serial): Change from goal to a variable.
	(.PHONY): Drop c.serial.
gcc/ada/
	* gcc-interface/Make-lang.in (ada.serial): Change from goal to a
	variable.
	(.PHONY): Drop ada.serial and ada.prev.
	(gnat1$(exeext)): Depend on $(ada.serial) rather than ada.serial.
gcc/brig/
	* Make-lang.in (brig.serial): Change from goal to a variable.
	(.PHONY): Drop brig.serial and brig.prev.
	(brig1$(exeext)): Depend on $(brig.serial) rather than brig.serial.
gcc/cp/
	* Make-lang.in (c++.serial): Change from goal to a variable.
	(.PHONY): Drop c++.serial and c++.prev.
	(cc1plus$(exeext)): Depend on $(c++.serial) rather than c++.serial.
gcc/d/
	* Make-lang.in (d.serial): Change from goal to a variable.
	(.PHONY): Drop d.serial and d.prev.
	(d21$(exeext)): Depend on $(d.serial) rather than d.serial.
gcc/fortran/
	* Make-lang.in (fortran.serial): Change from goal to a variable.
	(.PHONY): Drop fortran.serial and fortran.prev.
	(f951$(exeext)): Depend on $(fortran.serial) rather than
	fortran.serial.
gcc/go/
	* Make-lang.in (go.serial): Change from goal to a variable.
	(.PHONY): Drop go.serial and go.prev.
	(go1$(exeext)): Depend on $(go.serial) rather than go.serial.
gcc/jit/
	* Make-lang.in (jit.serial): Change from goal to a
	variable.
	(.PHONY): Drop jit.serial and jit.prev.
	($(LIBGCCJIT_FILENAME)): Depend on $(jit.serial) rather than
	jit.serial.
gcc/lto/
	* Make-lang.in (lto1.serial, lto2.serial): Change from goals to
	variables.
	(.PHONY): Drop lto1.serial, lto2.serial, lto1.prev and lto2.prev.
	($(LTO_EXE)): Depend on $(lto1.serial) rather than lto1.serial.
	($(LTO_DUMP_EXE)): Depend on $(lto2.serial) rather than lto2.serial.
gcc/objc/
	* Make-lang.in (objc.serial): Change from goal to a variable.
	(.PHONY): Drop objc.serial and objc.prev.
	(cc1obj$(exeext)): Depend on $(objc.serial) rather than objc.serial.
gcc/objcp/
	* Make-lang.in (obj-c++.serial): Change from goal to a variable.
	(.PHONY): Drop obj-c++.serial and obj-c++.prev.
	(cc1objplus$(exeext)): Depend on $(obj-c++.serial) rather than
	obj-c++.serial.

13 files changed, 40 insertions, 40 deletions

diff --git a/gcc/ada/gcc-interface/Make-lang.in b/gcc/ada/gcc-interface/Make-lang.in
index e414657..89b5750 100644
--- a/gcc/ada/gcc-interface/Make-lang.in
+++ b/gcc/ada/gcc-interface/Make-lang.in
@@ -146,10 +146,10 @@ endif
 
 # Define the names for selecting Ada in LANGUAGES.
 ada: gnat1$(exeext) gnatbind$(exeext)
-ada.serial: gnat1$(exeext)
+ada.serial = gnat1$(exeext)
 
 # Tell GNU Make to ignore these, if they exist.
-.PHONY: ada ada.serial ada.prev
+.PHONY: ada
 
 # Compute the FLAGS to pass for gnattools, now linked with a C++ driver as
 # we're linking against at least libcommon which contains C++ compiled code.
@@ -669,7 +669,7 @@ ada/libgnat/s-excmac.adb: $(srcdir)/ada/libgnat/s-excmac__$(EH_MECHANISM).adb
 # Since the RTL should be built with the latest compiler, remove the
 #  stamp target in the parent directory whenever gnat1 is rebuilt
 gnat1$(exeext): $(TARGET_ADA_SRCS) $(GNAT1_OBJS) $(ADA_BACKEND) libcommon-target.a \
-		$(LIBDEPS) ada.prev
+		$(LIBDEPS) $(ada.prev)
 	@$(call LINK_PROGRESS,$(INDEX.ada),start)
 	+$(GCC_LLINK) -o $@ $(GNAT1_OBJS) $(ADA_BACKEND) \
 	  libcommon-target.a $(LIBS) $(SYSLIBS) $(BACKENDLIBS) $(CFLAGS)
diff --git a/gcc/brig/Make-lang.in b/gcc/brig/Make-lang.in
index dffc750..0141b982 100644
--- a/gcc/brig/Make-lang.in
+++ b/gcc/brig/Make-lang.in
@@ -29,9 +29,9 @@ GCCBRIG_TARGET_INSTALL_NAME := $(target_noncanonical)-$(shell echo gccbrig|sed \
 
 # The name for selecting brig in LANGUAGES.
 brig: brig1$(exeext)
-brig.serial: brig
+brig.serial = brig1$(exeext)
 
-.PHONY: brig brig.serial brig.prev
+.PHONY: brig
 
 CFLAGS-brig/brigspec.o += $(DRIVER_DEFINES)
 
@@ -82,7 +82,7 @@ BRIG_OBJS = \
 
 brig_OBJS = $(BRIG_OBJS) brig/brigspec.o
 
-brig1$(exeext): $(BRIG_OBJS) attribs.o $(BACKEND) $(LIBDEPS) brig.prev
+brig1$(exeext): $(BRIG_OBJS) attribs.o $(BACKEND) $(LIBDEPS) $(brig.prev)
 	@$(call LINK_PROGRESS,$(INDEX.brig),start)
 	+$(LLINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
 	      $(BRIG_OBJS) attribs.o $(BACKEND) $(LIBS) \
diff --git a/gcc/c/Make-lang.in b/gcc/c/Make-lang.in
index c776ab6..4b2e616 100644
--- a/gcc/c/Make-lang.in
+++ b/gcc/c/Make-lang.in
@@ -37,10 +37,10 @@
 #
 # Define the names for selecting c in LANGUAGES.
 c: cc1$(exeext)
-c.serial: c
+c.serial = cc1$(exeext)
 
 # Tell GNU make to ignore these if they exist.
-.PHONY: c gcc c.serial
+.PHONY: c gcc
 
 # The C front end driver.  This is different from the drivers for other
 # front ends, because there is no C language specific driver (i.e. nothing
diff --git a/gcc/configure b/gcc/configure
index 9c70db2..3316dd7 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -30913,7 +30913,7 @@ echo "SERIAL_LIST =" >> Make-hooks
 echo else >> Make-hooks
 lang_cnt=0
 lang_list=
-prev=c.serial
+prev=c
 serialization_languages=c
 for lang in $all_selected_languages
 do
@@ -30929,7 +30929,7 @@ do
 	test $lang = c && continue
 	lang_cnt=`expr $lang_cnt + 1`
 	lang_list=" $prev$lang_list"
-	prev=${lang}.serial
+	prev=${lang}
 done
 echo "SERIAL_LIST = \$(wordlist \$(DO_LINK_SERIALIZATION),$lang_cnt,$lang_list)" >> Make-hooks
 echo endif >> Make-hooks
@@ -30939,7 +30939,7 @@ lang_idx=1
 for lang in $serialization_languages
 do
 	test $lang = c && continue
-	echo "$lang.prev: \$(word $lang_cnt,\$(SERIAL_LIST))" >> Make-hooks
+	echo "$lang.prev = \$(if \$(word $lang_cnt,\$(SERIAL_LIST)),\$(\$(word $lang_cnt,\$(SERIAL_LIST)).serial))" >> Make-hooks
 	echo "INDEX.$lang = $lang_idx" >> Make-hooks
 	lang_cnt=`expr $lang_cnt - 1`
 	lang_idx=`expr $lang_idx + 1`
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 1cce371..b410428 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -6934,7 +6934,7 @@ echo "SERIAL_LIST =" >> Make-hooks
 echo else >> Make-hooks
 lang_cnt=0
 lang_list=
-prev=c.serial
+prev=c
 serialization_languages=c
 for lang in $all_selected_languages
 do
@@ -6950,7 +6950,7 @@ do
 	test $lang = c && continue
 	lang_cnt=`expr $lang_cnt + 1`
 	lang_list=" $prev$lang_list"
-	prev=${lang}.serial
+	prev=${lang}
 done
 echo "SERIAL_LIST = \$(wordlist \$(DO_LINK_SERIALIZATION),$lang_cnt,$lang_list)" >> Make-hooks
 echo endif >> Make-hooks
@@ -6960,7 +6960,7 @@ lang_idx=1
 for lang in $serialization_languages
 do
 	test $lang = c && continue
-	echo "$lang.prev: \$(word $lang_cnt,\$(SERIAL_LIST))" >> Make-hooks
+	echo "$lang.prev = \$(if \$(word $lang_cnt,\$(SERIAL_LIST)),\$(\$(word $lang_cnt,\$(SERIAL_LIST)).serial))" >> Make-hooks
 	echo "INDEX.$lang = $lang_idx" >> Make-hooks
 	lang_cnt=`expr $lang_cnt - 1`
 	lang_idx=`expr $lang_idx + 1`
diff --git a/gcc/cp/Make-lang.in b/gcc/cp/Make-lang.in
index 6be4678..52b1dba 100644
--- a/gcc/cp/Make-lang.in
+++ b/gcc/cp/Make-lang.in
@@ -47,10 +47,10 @@ CP_PLUGIN_HEADERS := cp-tree.h cxx-pretty-print.h name-lookup.h type-utils.h ope
 # into the C++ rule, but that needs a little bit of work
 # to do the right thing within all.cross.
 c++: cc1plus$(exeext)
-c++.serial: c++
+c++.serial = cc1plus$(exeext)
 
 # Tell GNU make to ignore these if they exist.
-.PHONY: c++ c++.serial c++.prev
+.PHONY: c++
 
 CFLAGS-cp/g++spec.o += $(DRIVER_DEFINES)
 
@@ -117,7 +117,7 @@ cc1plus-checksum.c : build/genchecksum$(build_exeext) checksum-options \
 	  $(srcdir)/../move-if-change cc1plus-checksum.c.tmp cc1plus-checksum.c; \
 	fi
 
-cc1plus$(exeext): $(CXX_OBJS) cc1plus-checksum.o $(BACKEND) $(LIBDEPS) c++.prev
+cc1plus$(exeext): $(CXX_OBJS) cc1plus-checksum.o $(BACKEND) $(LIBDEPS) $(c++.prev)
 	@$(call LINK_PROGRESS,$(INDEX.c++),start)
 	+$(LLINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
 	      $(CXX_OBJS) cc1plus-checksum.o $(BACKEND) $(LIBS) $(BACKENDLIBS)
diff --git a/gcc/d/Make-lang.in b/gcc/d/Make-lang.in
index 0242c9c..8c0c753 100644
--- a/gcc/d/Make-lang.in
+++ b/gcc/d/Make-lang.in
@@ -27,10 +27,10 @@ D_LIBPHOBOS = -DLIBPHOBOS=\"gphobos\"
 
 # The name for selecting d in LANGUAGES.
 d: d21$(exeext)
-d.serial: d
+d.serial = d21$(exeext)
 
 # Tell GNU make to ignore these if they exist.
-.PHONY: d d.serial d.prev
+.PHONY: d
 
 # Create the compiler driver for D.
 CFLAGS-d/d-spec.o += $(DRIVER_DEFINES) $(D_LIBPHOBOS)
@@ -163,7 +163,7 @@ D_ALL_OBJS = $(D_FRONTEND_OBJS) $(D_GENERATED_OBJS) $(D_OBJS) $(D_TARGET_OBJS)
 
 d_OBJS = $(D_ALL_OBJS) d/d-spec.o
 
-d21$(exeext): $(D_ALL_OBJS) attribs.o $(BACKEND) $(LIBDEPS) d.prev
+d21$(exeext): $(D_ALL_OBJS) attribs.o $(BACKEND) $(LIBDEPS) $(d.prev)
 	@$(call LINK_PROGRESS,$(INDEX.d),start)
 	+$(LLINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
 		$(D_ALL_OBJS) attribs.o $(BACKEND) $(LIBS) $(BACKENDLIBS)
diff --git a/gcc/fortran/Make-lang.in b/gcc/fortran/Make-lang.in
index ea2e49b..4afd874 100644
--- a/gcc/fortran/Make-lang.in
+++ b/gcc/fortran/Make-lang.in
@@ -72,10 +72,10 @@ fortran_OBJS = $(F95_OBJS) fortran/gfortranspec.o
 #
 # Define the names for selecting gfortran in LANGUAGES.
 fortran: f951$(exeext)
-fortran.serial: fortran
+fortran.serial = f951$(exeext)
 
 # Tell GNU make to ignore files by these names if they exist.
-.PHONY: fortran fortran.serial fortran.prev
+.PHONY: fortran
 
 CFLAGS-fortran/gfortranspec.o += $(DRIVER_DEFINES)
 
@@ -93,7 +93,7 @@ gfortran-cross$(exeext): gfortran$(exeext)
 	cp gfortran$(exeext) gfortran-cross$(exeext)
 
 # The compiler itself is called f951.
-f951$(exeext): $(F95_OBJS) $(BACKEND) $(LIBDEPS) attribs.o fortran.prev
+f951$(exeext): $(F95_OBJS) $(BACKEND) $(LIBDEPS) attribs.o $(fortran.prev)
 	@$(call LINK_PROGRESS,$(INDEX.fortran),start)
 	+$(LLINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
 		$(F95_OBJS) $(BACKEND) $(ZLIB) $(LIBS) attribs.o \
diff --git a/gcc/go/Make-lang.in b/gcc/go/Make-lang.in
index 7c586cb..a987127 100644
--- a/gcc/go/Make-lang.in
+++ b/gcc/go/Make-lang.in
@@ -27,9 +27,9 @@ GCCGO_TARGET_INSTALL_NAME := $(target_noncanonical)-$(shell echo gccgo|sed '$(pr
 
 # The name for selecting go in LANGUAGES.
 go: go1$(exeext)
-go.serial: go
+go.serial = go1$(exeext)
 
-.PHONY: go go.serial go.prev
+.PHONY: go
 
 CFLAGS-go/gospec.o += $(DRIVER_DEFINES)
 
@@ -79,7 +79,7 @@ GO_OBJS = \
 
 go_OBJS = $(GO_OBJS) go/gospec.o
 
-go1$(exeext): $(GO_OBJS) attribs.o $(BACKEND) $(LIBDEPS) go.prev
+go1$(exeext): $(GO_OBJS) attribs.o $(BACKEND) $(LIBDEPS) $(go.prev)
 	@$(call LINK_PROGRESS,$(INDEX.go),start)
 	+$(LLINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
 	      $(GO_OBJS) attribs.o $(BACKEND) $(LIBS) $(BACKENDLIBS)
diff --git a/gcc/jit/Make-lang.in b/gcc/jit/Make-lang.in
index 012f62d..1d34d2a0 100644
--- a/gcc/jit/Make-lang.in
+++ b/gcc/jit/Make-lang.in
@@ -81,10 +81,10 @@ jit: $(LIBGCCJIT_FILENAME) \
 	$(FULL_DRIVER_NAME)
 endif
 
-jit.serial: $(LIBGCCJIT_FILENAME)
+jit.serial = $(LIBGCCJIT_FILENAME)
 
 # Tell GNU make to ignore these if they exist.
-.PHONY: jit jit.serial jit.prev
+.PHONY: jit
 
 jit_OBJS = attribs.o \
 	jit/dummy-frontend.o \
@@ -119,7 +119,7 @@ $(LIBGCCJIT_FILENAME): $(jit_OBJS) \
 	libbackend.a libcommon-target.a libcommon.a \
 	$(CPPLIB) $(LIBDECNUMBER) \
 	$(LIBDEPS) $(srcdir)/jit/libgccjit.map \
-	$(EXTRA_GCC_OBJS) jit.prev
+	$(EXTRA_GCC_OBJS) $(jit.prev)
 	@$(call LINK_PROGRESS,$(INDEX.jit),start)
 	+$(LLINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ -shared \
 	     $(jit_OBJS) libbackend.a libcommon-target.a libcommon.a \
diff --git a/gcc/lto/Make-lang.in b/gcc/lto/Make-lang.in
index 4a03f19..6e5fbac 100644
--- a/gcc/lto/Make-lang.in
+++ b/gcc/lto/Make-lang.in
@@ -42,10 +42,10 @@ lto_dump_OBJS = $(LTO_DUMP_OBJS)
 # Rules
 
 lto: $(LTO_EXE) $(LTO_DUMP_EXE)
-lto1.serial: $(LTO_EXE)
-lto2.serial: $(LTO_DUMP_EXE)
+lto1.serial = $(LTO_EXE)
+lto2.serial = $(LTO_DUMP_EXE)
 
-.PHONY: lto lto1.serial lto1.prev lto2.serial lto2.prev
+.PHONY: lto
 
 # These hooks are used by the main GCC Makefile.  Consult that
 # Makefile for documentation.
@@ -90,13 +90,13 @@ lto.stagefeedback:
 # Use strict warnings for this front end.
 lto-warn = $(STRICT_WARN)
 
-$(LTO_EXE): $(LTO_OBJS) $(BACKEND) $(LIBDEPS) lto1.prev
+$(LTO_EXE): $(LTO_OBJS) $(BACKEND) $(LIBDEPS) $(lto1.prev)
 	@$(call LINK_PROGRESS,$(INDEX.lto1),start)
 	+$(LLINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
 		$(LTO_OBJS) $(BACKEND) $(BACKENDLIBS) $(LIBS)
 	@$(call LINK_PROGRESS,$(INDEX.lto1),end)
 
-$(LTO_DUMP_EXE): $(LTO_DUMP_OBJS) $(BACKEND) $(LIBDEPS) lto2.prev
+$(LTO_DUMP_EXE): $(LTO_DUMP_OBJS) $(BACKEND) $(LIBDEPS) $(lto2.prev)
 	@$(call LINK_PROGRESS,$(INDEX.lto2),start)
 	+$(LLINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
 		$(LTO_DUMP_OBJS) $(BACKEND) $(BACKENDLIBS) $(LIBS)
diff --git a/gcc/objc/Make-lang.in b/gcc/objc/Make-lang.in
index a19befb..2edf0a9 100644
--- a/gcc/objc/Make-lang.in
+++ b/gcc/objc/Make-lang.in
@@ -38,10 +38,10 @@
 #
 # Define the names for selecting Objective-C in LANGUAGES.
 objc: cc1obj$(exeext)
-objc.serial: objc
+objc.serial = cc1obj$(exeext)
 
 # Tell GNU make to ignore these if they exist.
-.PHONY: objc objc.serial objc.prev
+.PHONY: objc
 
 # Use maximal warnings for this front end.
 objc-warn = $(STRICT_WARN)
@@ -64,7 +64,7 @@ cc1obj-checksum.c : build/genchecksum$(build_exeext) checksum-options \
 	$(srcdir)/../move-if-change cc1obj-checksum.c.tmp cc1obj-checksum.c
 
 cc1obj$(exeext): $(OBJC_OBJS) $(C_AND_OBJC_OBJS) cc1obj-checksum.o $(BACKEND) \
-		 $(LIBDEPS) objc.prev
+		 $(LIBDEPS) $(objc.prev)
 	@$(call LINK_PROGRESS,$(INDEX.objc),start)
 	+$(LLINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
 	      $(OBJC_OBJS) $(C_AND_OBJC_OBJS) cc1obj-checksum.o \
diff --git a/gcc/objcp/Make-lang.in b/gcc/objcp/Make-lang.in
index 2f6954e..2e3e37e 100644
--- a/gcc/objcp/Make-lang.in
+++ b/gcc/objcp/Make-lang.in
@@ -39,10 +39,10 @@
 #
 # Define the names for selecting Objective-C++ in LANGUAGES.
 obj-c++: cc1objplus$(exeext)
-obj-c++.serial: obj-c++
+obj-c++.serial = cc1objplus$(exeext)
 
 # Tell GNU make to ignore these if they exist.
-.PHONY: obj-c++ obj-c++.serial obj-c++.prev
+.PHONY: obj-c++
 
 # Use maximal warnings for this front end.  Also, make ObjC and C++
 # headers accessible.
@@ -68,7 +68,7 @@ cc1objplus-checksum.c : build/genchecksum$(build_exeext) checksum-options \
 	cc1objplus-checksum.c
 
 cc1objplus$(exeext): $(OBJCXX_OBJS) cc1objplus-checksum.o $(BACKEND) \
-		     $(LIBDEPS) obj-c++.prev
+		     $(LIBDEPS) $(obj-c++.prev)
 	@$(call LINK_PROGRESS,$(INDEX.obj-c++),start)
 	+$(LLINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
 		$(OBJCXX_OBJS) cc1objplus-checksum.o $(BACKEND) $(LIBS) $(BACKENDLIBS)