needed-list fails in libiberty

[Eli Zaretskii <eliz@gnu.org>]

The following snippet from libiberty/Makefile.in:

    # needed-list is used by libstdc++.  NEEDED is the list of functions
    # to include there.  Do not add anything LGPL to this list; libstdc++
    # can't use anything encumbering.
    NEEDED = atexit calloc memchr memcmp memcpy memmove memset rename strchr \
	     strerror strncmp strrchr strstr strtol strtoul tmpnam vfprintf vprintf \
	     vfork waitpid bcmp bcopy bzero
    needed-list: Makefile
	    rm -f needed-list; touch needed-list; \
	    for f in $(NEEDED); do \
	      for g in $(LIBOBJS) $(EXTRA_OFILES); do \
		case "$$g" in \
		  *$$f*) echo $$g >> needed-list ;; \
		esac; \
	      done; \
	    done

assumes that either $(LIBOBJS) or $(EXTRA_OFILES), or both, will be
non-empty.  If that assumption is wrong, building libiberty fails:

    rm -f needed-list; touch needed-list; \
    for f in atexit calloc memchr memcmp memcpy memmove memset rename strchr strerror strncmp strrchr strstr strtol strtoul tmpnam vfprintf vprintf vfork waitpid bcmp bcopy bzero; do \
      for g in  ; do \
	case "$g" in \
	  *$f*) echo $g >> needed-list ;; \
	esac; \
      done; \
    done
    d:\usr\tmp/dj850000: line 1: syntax error near unexpected token `;'

This was in a DJGPP build of GDB, and the root cause of $(LIBOBJS)
being empty was another bug (see my other mail today about "libiberty
configuration for DJGPP").  But in principle, some build that has all
of the required functions in the system library can potentially fail
in the same way, no?

So how about the following patch?

2009-04-14  Eli Zaretskii  <eliz@gnu.org>

	* Makefile.in (needed-list): Add "notused" to the list of the
	inner `for', to avoid failure when both $(LIBOBJS) and
	$(EXTRA_OFILES) are empty.


--- libiberty/Makefile.i~0	2009-03-28 05:07:29.000000000 +0300
+++ libiberty/Makefile.in	2009-04-11 12:27:37.284000000 +0300
@@ -383,10 +383,12 @@
 NEEDED = atexit calloc memchr memcmp memcpy memmove memset rename strchr \
 	 strerror strncmp strrchr strstr strtol strtoul tmpnam vfprintf vprintf \
 	 vfork waitpid bcmp bcopy bzero
+# The notused gork is for when both LIBOBJS and EXTRA_OFILES end up
+# empty: the for loop will then barf.
 needed-list: Makefile
 	rm -f needed-list; touch needed-list; \
 	for f in $(NEEDED); do \
-	  for g in $(LIBOBJS) $(EXTRA_OFILES); do \
+	  for g in $(LIBOBJS) $(EXTRA_OFILES) notused; do \
 	    case "$$g" in \
 	      *$$f*) echo $$g >> needed-list ;; \
 	    esac; \