Make etags path used by build system configurable

This commit allows users to specify a path to their "etags"
executable for use when doing "make tags".
I based this patch off of this one from upstream automake:
https://git.savannah.gnu.org/cgit/automake.git/commit/m4?id=d2ccbd7eb38d6a4277d6f42b994eb5a29b1edf29
This means that I just supplied variables that the user can override
for the tags programs, rather than having the configure scripts
actually check for them. I handle etags and ctags separately because
the intl subdirectory has separate targets for them. This commit
only affects the subdirectories that use handwritten Makefiles; the
ones that use automake will have to wait until we update the version
of automake used to be 1.16.4 or newer before they'll be fixed.

Addresses #103021

gcc/ChangeLog:

	PR other/103021
	* Makefile.in: Substitute CTAGS, ETAGS, and CSCOPE
	variables. Use ETAGS variable in TAGS target.
	* configure: Regenerate.
	* configure.ac: Allow CTAGS, ETAGS, and CSCOPE
	variables to be overridden.

gcc/ada/ChangeLog:

	PR other/103021
	* gcc-interface/Make-lang.in: Use ETAGS variable in
	TAGS target.

gcc/c/ChangeLog:

	PR other/103021
	* Make-lang.in: Use ETAGS variable in TAGS target.

gcc/cp/ChangeLog:

	PR other/103021
	* Make-lang.in: Use ETAGS variable in TAGS target.

gcc/d/ChangeLog:

	PR other/103021
	* Make-lang.in: Use ETAGS variable in TAGS target.

gcc/fortran/ChangeLog:

	PR other/103021
	* Make-lang.in: Use ETAGS variable in TAGS target.

gcc/go/ChangeLog:

	PR other/103021
	* Make-lang.in: Use ETAGS variable in TAGS target.

gcc/objc/ChangeLog:

	PR other/103021
	* Make-lang.in: Use ETAGS variable in TAGS target.

gcc/objcp/ChangeLog:

	PR other/103021
	* Make-lang.in: Use ETAGS variable in TAGS target.

intl/ChangeLog:

	PR other/103021
	* Makefile.in: Use ETAGS variable in TAGS target,
	CTAGS variable in CTAGS target, and MKID variable
	in ID target.
	* configure: Regenerate.
	* configure.ac: Allow CTAGS, ETAGS, and MKID
	variables to be overridden.

libcpp/ChangeLog:

	PR other/103021
	* Makefile.in: Use ETAGS variable in TAGS target.
	* configure: Regenerate.
	* configure.ac: Allow ETAGS variable to be overridden.

libiberty/ChangeLog:

	PR other/103021
	* Makefile.in: Use ETAGS variable in TAGS target.
	* configure: Regenerate.
	* configure.ac: Allow ETAGS variable to be overridden.

11 files changed, 55 insertions, 20 deletions

diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index a4344d6..7054201 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -4319,6 +4319,10 @@ paranoia: paranoia.o real.o $(LIBIBERTY)
 
 # These exist for maintenance purposes.
 
+CTAGS=@CTAGS@
+ETAGS=@ETAGS@
+CSCOPE=@CSCOPE@
+
 # Update the tags table.
 TAGS: lang.tags
 	(cd $(srcdir);					\
@@ -4328,14 +4332,14 @@ TAGS: lang.tags
 	    incs="$$incs --include $$dir/TAGS.sub";	\
 	  fi;						\
 	done;						\
-	etags -o TAGS.sub c-family/*.h c-family/*.c c-family/*.cc \
+	$(ETAGS) -o TAGS.sub c-family/*.h c-family/*.c c-family/*.cc \
 	      *.h *.c *.cc \
 	      ../include/*.h ../libiberty/*.c \
 	      ../libcpp/*.c ../libcpp/include/*.h \
 	      --language=none --regex="/\(char\|unsigned int\|int\|bool\|void\|HOST_WIDE_INT\|enum [A-Za-z_0-9]+\) [*]?\([A-Za-z_0-9]+\)/\2/" common.opt	\
 	      --language=none --regex="/\(DEF_RTL_EXPR\|DEFTREECODE\|DEFGSCODE\|DEFTIMEVAR\|DEFPARAM\|DEFPARAMENUM5\)[ ]?(\([A-Za-z_0-9]+\)/\2/" rtl.def tree.def gimple.def timevar.def \
 		; \
-	etags --include TAGS.sub $$incs)
+	$(ETAGS) --include TAGS.sub $$incs)
 
 # -----------------------------------------------------
 # Rules for generating translated message descriptions.
diff --git a/gcc/ada/gcc-interface/Make-lang.in b/gcc/ada/gcc-interface/Make-lang.in
index ae5158a..c01945b 100644
--- a/gcc/ada/gcc-interface/Make-lang.in
+++ b/gcc/ada/gcc-interface/Make-lang.in
@@ -805,8 +805,8 @@ ada.srcextra:
 ada.srcman:
 
 ada.tags: force
-	cd $(srcdir)/ada && etags -o TAGS.sub *.c *.h *.ads *.adb && \
-	etags --include TAGS.sub --include ../TAGS.sub
+	cd $(srcdir)/ada && $(ETAGS) -o TAGS.sub *.c *.h *.ads *.adb && \
+	$(ETAGS) --include TAGS.sub --include ../TAGS.sub
 
 
 # Generate documentation.
diff --git a/gcc/c/Make-lang.in b/gcc/c/Make-lang.in
index 67a40fc..9090096 100644
--- a/gcc/c/Make-lang.in
+++ b/gcc/c/Make-lang.in
@@ -109,8 +109,8 @@ c.srcinfo:
 c.srcextra: gengtype-lex.c
 	-cp -p $^ $(srcdir)
 c.tags: force
-	cd $(srcdir)/c; etags -o TAGS.sub *.c *.h; \
-	etags --include TAGS.sub --include ../TAGS.sub
+	cd $(srcdir)/c; $(ETAGS) -o TAGS.sub *.c *.h; \
+	$(ETAGS) --include TAGS.sub --include ../TAGS.sub
 c.man:
 c.srcman:
 
diff --git a/gcc/configure b/gcc/configure
index 74b9d9b..40b5ed9 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -714,6 +714,9 @@ gcc_tooldir
 enable_lto
 DO_LINK_SERIALIZATION
 DO_LINK_MUTEX
+CSCOPE
+ETAGS
+CTAGS
 MAINT
 zlibinc
 zlibdir
@@ -19455,7 +19458,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 19458 "configure"
+#line 19461 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -19561,7 +19564,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 19564 "configure"
+#line 19567 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -31378,6 +31381,19 @@ else
   MAINT='#'
 fi
 
+if test -z "$CTAGS"; then
+  CTAGS=ctags
+fi
+
+if test -z "$ETAGS"; then
+  ETAGS=etags
+fi
+
+if test -z "$CSCOPE"; then
+  CSCOPE=cscope
+fi
+
+
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to avoid linking multiple front-ends at once" >&5
 $as_echo_n "checking whether to avoid linking multiple front-ends at once... " >&6; }
@@ -33941,3 +33957,4 @@ $as_echo "$as_me: WARNING: unrecognized options: $ac_unrecognized_opts" >&2;}
 fi
 
 
+_AC_FINALIZE
diff --git a/gcc/configure.ac b/gcc/configure.ac
index c9ee1fb..aa2f6d8 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -7040,6 +7040,20 @@ else
 fi
 AC_SUBST(MAINT)dnl
 
+dnl Variables for tags utilities; copied from automake 1.16.4+'s init.m4
+if test -z "$CTAGS"; then
+  CTAGS=ctags
+fi
+AC_SUBST([CTAGS])
+if test -z "$ETAGS"; then
+  ETAGS=etags
+fi
+AC_SUBST([ETAGS])
+if test -z "$CSCOPE"; then
+  CSCOPE=cscope
+fi
+AC_SUBST([CSCOPE])
+
 dnl Whether to prevent multiple front-ends from linking at the same time
 
 AC_MSG_CHECKING([whether to avoid linking multiple front-ends at once])
diff --git a/gcc/cp/Make-lang.in b/gcc/cp/Make-lang.in
index de1fc02..3dfa9ce 100644
--- a/gcc/cp/Make-lang.in
+++ b/gcc/cp/Make-lang.in
@@ -174,9 +174,9 @@ c++.srcinfo:
 c++.srcextra:
 
 c++.tags: force
-	cd $(srcdir)/cp; etags -o TAGS.sub *.c *.cc *.h --language=none \
+	cd $(srcdir)/cp; $(ETAGS) -o TAGS.sub *.c *.cc *.h --language=none \
 	  --regex='/DEFTREECODE [(]\([A-Z_]+\)/\1/' cp-tree.def; \
-	etags --include TAGS.sub --include ../TAGS.sub
+	$(ETAGS) --include TAGS.sub --include ../TAGS.sub
 
 c++.man: doc/g++.1
 
diff --git a/gcc/d/Make-lang.in b/gcc/d/Make-lang.in
index 554a26e..1ed8134 100644
--- a/gcc/d/Make-lang.in
+++ b/gcc/d/Make-lang.in
@@ -221,8 +221,8 @@ d.srcextra:
 
 d.tags: force
 	cd $(srcdir)/d; \
-	etags -o TAGS.sub *.c *.cc *.h dmd/*.c dmd/*.h dmd/root/*.h dmd/root/*.c; \
-	etags --include TAGS.sub --include ../TAGS.sub
+	$(ETAGS) -o TAGS.sub *.c *.cc *.h dmd/*.c dmd/*.h dmd/root/*.h dmd/root/*.c; \
+	$(ETAGS) --include TAGS.sub --include ../TAGS.sub
 
 d.man: doc/gdc.1
 d.srcman: doc/gdc.1
diff --git a/gcc/fortran/Make-lang.in b/gcc/fortran/Make-lang.in
index 58ce589..414f3eb 100644
--- a/gcc/fortran/Make-lang.in
+++ b/gcc/fortran/Make-lang.in
@@ -113,8 +113,8 @@ fortran.srcinfo: doc/gfortran.info
 	-cp -p $^ $(srcdir)/fortran
 
 fortran.tags: force
-	cd $(srcdir)/fortran; etags -o TAGS.sub *.c *.h; \
-	etags --include TAGS.sub --include ../TAGS.sub
+	cd $(srcdir)/fortran; $(ETAGS) -o TAGS.sub *.c *.h; \
+	$(ETAGS) --include TAGS.sub --include ../TAGS.sub
 
 fortran.info: doc/gfortran.info doc/gfc-internals.info
 
diff --git a/gcc/go/Make-lang.in b/gcc/go/Make-lang.in
index 4bdc8f6..6fdf55b 100644
--- a/gcc/go/Make-lang.in
+++ b/gcc/go/Make-lang.in
@@ -133,8 +133,8 @@ go.srcinfo: doc/gccgo.info
 go.srcextra:
 go.tags: force
 	cd $(srcdir)/go; \
-	etags -o TAGS.sub *.c *.h gofrontend/*.h gofrontend/*.cc; \
-	etags --include TAGS.sub --include ../TAGS.sub
+	$(ETAGS) -o TAGS.sub *.c *.h gofrontend/*.h gofrontend/*.cc; \
+	$(ETAGS) --include TAGS.sub --include ../TAGS.sub
 go.man: doc/gccgo.1
 go.srcman: doc/gccgo.1
 	-cp -p $^ $(srcdir)/doc
diff --git a/gcc/objc/Make-lang.in b/gcc/objc/Make-lang.in
index d3f99c8..2a94815 100644
--- a/gcc/objc/Make-lang.in
+++ b/gcc/objc/Make-lang.in
@@ -102,8 +102,8 @@ objc.srcman:
 objc.install-plugin:
 
 objc.tags: force
-	cd $(srcdir)/objc; etags -o TAGS.sub *.c *.h; \
-	etags --include TAGS.sub --include ../TAGS.sub
+	cd $(srcdir)/objc; $(ETAGS) -o TAGS.sub *.c *.h; \
+	$(ETAGS) --include TAGS.sub --include ../TAGS.sub
 
 lang_checks += check-objc
 
diff --git a/gcc/objcp/Make-lang.in b/gcc/objcp/Make-lang.in
index 1806386..33f448a 100644
--- a/gcc/objcp/Make-lang.in
+++ b/gcc/objcp/Make-lang.in
@@ -136,8 +136,8 @@ obj-c++.man:
 obj-c++.install-plugin:
 
 obj-c++.tags: force
-	cd $(srcdir)/objcp; etags -o TAGS.sub *.c *.h; \
-	etags --include TAGS.sub --include ../TAGS.sub
+	cd $(srcdir)/objcp; $(ETAGS) -o TAGS.sub *.c *.h; \
+	$(ETAGS) --include TAGS.sub --include ../TAGS.sub
 
 lang_checks += check-obj-c++