Makefile.in (options.h): Depend on Makefile.

	* Makefile.in (options.h): Depend on Makefile.  Add move-if-change
	to opts.sh command line.
	* opts.sh: Write to temporary files with a move-if-change at the end.

From-SVN: r69200

diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 8d9ceb8fd9b61c71c2f91a3594d984a83c70d728..a62873f27a0259207eb1d75399d5723070a2613e 100644 (file)
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -1416,9 +1416,10 @@ s-specs : Makefile
 
 options.c: $(lang_opt_files) $(srcdir)/opts.sh options.h intl.h
 
-options.h: $(lang_opt_files) $(srcdir)/opts.sh
-       AWK=$(AWK) $(SHELL) $(srcdir)/opts.sh options.c options.h \
-               $(lang_opt_files)
+options.h: $(lang_opt_files) $(srcdir)/opts.sh Makefile
+       AWK=$(AWK) $(SHELL) $(srcdir)/opts.sh \
+               '$(SHELL) $(srcdir)/move-if-change' \
+               options.c options.h $(lang_opt_files)
 
 dumpvers: dumpvers.c
 

diff --git a/gcc/opts.sh b/gcc/opts.sh
index 985cf9668c21833640c940dc907865c28a7bcedb..3509dfdafef7e11136ef2aa383318595def046de 100644 (file)
--- a/gcc/opts.sh
+++ b/gcc/opts.sh
@@ -17,7 +17,7 @@
 # along with this program; if not, write to the Free Software
 # Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 #
-# Usage: opts.sh outfile.c outfile.h file1.opt [file2.opt, ...]
+# Usage: opts.sh moveifchange srcdir outfile.c outfile.h file1.opt [ ...]
 
 # Always operate in the C locale.
 LANG=C
@@ -30,8 +30,11 @@ AWK=${AWK-awk}
 
 SORT=sort              # Could be /bin/sort or /usr/bin/sort
 
+MOVEIFCHANGE=$1; shift
 C_FILE=$1; shift
 H_FILE=$1; shift
+TMP_C_FILE=tmp-${C_FILE}
+TMP_H_FILE=tmp-${H_FILE}
 
 ${AWK} '
        # Ignore comments and blank lines
@@ -88,13 +91,14 @@ ${AWK} '
 # Dump out an enumeration into a .h file, and an array of options into a
 # C file.  Combine the flags of duplicate options.
     END {
-       c_file = "'${C_FILE}'"
-       h_file = "'${H_FILE}'"
+       c_file = "'${TMP_C_FILE}'"
+       h_file = "'${TMP_H_FILE}'"
+       realh_file = "'${H_FILE}'"
        comma = ","
 
        print "/* This file is auto-generated by opts.sh.  */\n" > c_file
        print "#include <intl.h>"                       >> c_file
-       print "#include \"" h_file "\""                 >> c_file
+       print "#include \"" realh_file "\""             >> c_file
        print "#include \"opts.h\"\n"                   >> c_file
        print "const char * const lang_names[] =\n{"    >> c_file
 
@@ -163,3 +167,8 @@ ${AWK} '
        print "};"                                      >> c_file
     }
 '
+
+# Copy the newly generated files back to the correct names only if different.
+# This is to prevent a cascade of file rebuilds when not necessary.
+${MOVEIFCHANGE} ${TMP_H_FILE} ${H_FILE}
+${MOVEIFCHANGE} ${TMP_C_FILE} ${C_FILE}