bfd/

	* elf-bfd.h (struct elf_obj_tdata): Delete dt_soname field.  Add
	dyn_lib_class field.  Rearrange for better packing.
	(elf_dt_soname): Delete.
	(elf_dyn_lib_class): Define.
	* elf.c (bfd_elf_set_dt_needed_name): Update comment.
	(bfd_elf_set_dt_needed_soname): Delete.
	(bfd_elf_set_dyn_lib_class): New function.
	* elflink.h (add_dt_needed_tag): New function.  Split out from..
	(elf_link_add_object_symbols): ..here.  Rename "name" to "soname".
	Use elf_dyn_lib_class to set dt_needed and add_needed.  Move fallback
	initialization of soname.
	(elf_link_check_versioned_symbol): Test elf_dyn_lib_class instead of
	elf_dt_soname.
	* bfd-in.h (enum dynamic_lib_link_class): New.
	(bfd_elf_set_dt_needed_soname): Delete.
	(bfd_elf_set_dyn_lib_class): Declare.
	* bfd-in2.h: Regenerate.
ld/
	* ld.texinfo: Add --as-needed doco.
	* ldmain.c (as_needed): New global var.
	* ldmain.h (as_needed): Declare.
	* lexsup.c (option_values): Add OPTION_AS_NEEDED and
	OPTION_NO_AS_NEEDED.
	(ld_options): Likewise.
	(parse_args): Handle them.
	* ldlang.h (lang_input_statement_type): Add as_needed field.
	* ldlang.c (new_afile): Set p->as_needed.
	* emultempl/elf32.em (gld${EMULATION_NAME}_load_symbols): New function.
	(gld${EMULATION_NAME}_try_needed): Use bfd_elf_set_dyn_lib_class.
	(ld_${EMULATION_NAME}_emulation): Set LDEMUL_RECOGNIZED_FILE entry.

	* ldlang.c (open_input_bfds): Remove useless cast.
	(lang_do_assignments_1): Likewise.
	(lang_for_each_input_section): Delete.

8 files changed, 87 insertions, 32 deletions

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 0b3407f..3c4940c 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,22 @@
+2004-03-18  Alan Modra  <amodra@bigpond.net.au>
+
+	* ld.texinfo: Add --as-needed doco.
+	* ldmain.c (as_needed): New global var.
+	* ldmain.h (as_needed): Declare.
+	* lexsup.c (option_values): Add OPTION_AS_NEEDED and
+	OPTION_NO_AS_NEEDED.
+	(ld_options): Likewise.
+	(parse_args): Handle them.
+	* ldlang.h (lang_input_statement_type): Add as_needed field.
+	* ldlang.c (new_afile): Set p->as_needed.
+	* emultempl/elf32.em (gld${EMULATION_NAME}_load_symbols): New function.
+	(gld${EMULATION_NAME}_try_needed): Use bfd_elf_set_dyn_lib_class.
+	(ld_${EMULATION_NAME}_emulation): Set LDEMUL_RECOGNIZED_FILE entry.
+
+	* ldlang.c (open_input_bfds): Remove useless cast.
+	(lang_do_assignments_1): Likewise.
+	(lang_for_each_input_section): Delete.
+
 2004-03-17  Ralf Corsepius <corsepiu@faw.uni-ulm.de>
 
 	* configure.tgt: Switch sh-*-rtems* to ELF.  Add sh-*-rtemscoff*.
diff --git a/ld/emultempl/elf32.em b/ld/emultempl/elf32.em
index 45749e7..e95b3a9 100644
--- a/ld/emultempl/elf32.em
+++ b/ld/emultempl/elf32.em
@@ -89,6 +89,28 @@ gld${EMULATION_NAME}_before_parse (void)
 EOF
 fi
 
+if test x"$LDEMUL_RECOGNIZED_FILE" != xgld"${EMULATION_NAME}"_load_symbols; then
+cat >>e${EMULATION_NAME}.c <<EOF
+/* Handle as_needed DT_NEEDED.  */
+
+static bfd_boolean
+gld${EMULATION_NAME}_load_symbols (lang_input_statement_type *entry)
+{
+  if (!entry->as_needed
+      || (bfd_get_file_flags (entry->the_bfd) & DYNAMIC) == 0)
+    return FALSE;
+
+  /* Tell the ELF linker that we don't want the output file to have a
+     DT_NEEDED entry for this file, unless it is used to resolve
+     references in a regular object.  */
+  bfd_elf_set_dyn_lib_class (entry->the_bfd, DYN_AS_NEEDED);
+
+  /* Continue on with normal load_symbols processing.  */
+  return FALSE;
+}
+EOF
+fi
+
 cat >>e${EMULATION_NAME}.c <<EOF
 
 /* These variables are required to pass information back and forth
@@ -336,14 +358,13 @@ cat >>e${EMULATION_NAME}.c <<EOF
       return TRUE;
     }
 
-  /* Tell the ELF backend that we don't want the output file to have a
-     DT_NEEDED entry for this file.  */
-  bfd_elf_set_dt_needed_name (abfd, "");
+  /* Specify the soname to use.  */
+  bfd_elf_set_dt_needed_name (abfd, soname);
 
-  /* Tell the ELF backend that the output file needs a DT_NEEDED
-     entry for this file if it is used to resolve the reference in
-     a regular object.  */
-  bfd_elf_set_dt_needed_soname (abfd, soname);
+  /* Tell the ELF linker that we don't want the output file to have a
+     DT_NEEDED entry for this file, unless it is used to resolve
+     references in a regular object.  */
+  bfd_elf_set_dyn_lib_class (abfd, DYN_DT_NEEDED);
 
   /* Add this file into the symbol table.  */
   if (! bfd_link_add_symbols (abfd, &link_info))
@@ -1752,7 +1773,7 @@ struct ld_emulation_xfer_struct ld_${EMULATION_NAME}_emulation =
   gld${EMULATION_NAME}_handle_option,
   ${LDEMUL_UNRECOGNIZED_FILE-NULL},
   ${LDEMUL_LIST_OPTIONS-gld${EMULATION_NAME}_list_options},
-  ${LDEMUL_RECOGNIZED_FILE-NULL},
+  ${LDEMUL_RECOGNIZED_FILE-gld${EMULATION_NAME}_load_symbols},
   ${LDEMUL_FIND_POTENTIAL_LIBRARIES-NULL},
   ${LDEMUL_NEW_VERS_PATTERN-NULL}
 };
diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index 9710f4f..4310c12 100644
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -972,6 +972,18 @@ behaviour from release 2.14 onwards is to reject such input files, and
 so the @samp{--accept-unknown-input-arch} option has been added to
 restore the old behaviour.
 
+@kindex --as-needed
+@kindex --no-as-needed
+@item --as-needed
+@itemx --no-as-needed
+This option affects ELF DT_NEEDED tags for dynamic libraries mentioned
+on the command line after the @option{--as-needed} option.  Normally,
+the linker will add a DT_NEEDED tag for each dynamic library mentioned
+on the command line, regardless of whether the library is actually
+needed. @option{--as-needed} causes DT_NEEDED tags to only be emitted
+for libraries that satisfy some reference from regular objects.
+@option{--no-as-needed} restores the default behaviour.
+
 @kindex -assert @var{keyword}
 @item -assert @var{keyword}
 This option is ignored for SunOS compatibility.
diff --git a/ld/ldlang.c b/ld/ldlang.c
index 3855998..0c08601 100644
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -445,6 +445,7 @@ new_afile (const char *name,
   p->next = NULL;
   p->symbol_count = 0;
   p->dynamic = config.dynamic_link;
+  p->as_needed = as_needed;
   p->whole_archive = whole_archive;
   p->loaded = FALSE;
   lang_statement_append (&input_file_chain,
@@ -1842,7 +1843,7 @@ open_input_bfds (lang_statement_union_type *s, bfd_boolean force)
 	  /* Maybe we should load the file's symbols.  */
 	  if (s->wild_statement.filename
 	      && ! wildcardp (s->wild_statement.filename))
-	    (void) lookup_name (s->wild_statement.filename);
+	    lookup_name (s->wild_statement.filename);
 	  open_input_bfds (s->wild_statement.children.head, force);
 	  break;
 	case lang_group_statement_enum:
@@ -3348,8 +3349,7 @@ lang_do_assignments_1
 	    if (os->bfd_section != NULL)
 	      {
 		dot = os->bfd_section->vma;
-		(void) lang_do_assignments_1 (os->children.head, os,
-					      os->fill, dot);
+		lang_do_assignments_1 (os->children.head, os, os->fill, dot);
 		dot = (os->bfd_section->vma
 		       + TO_ADDR (os->bfd_section->_raw_size));
 
@@ -3938,24 +3938,6 @@ lang_for_each_file (void (*func) (lang_input_statement_type *))
     }
 }
 
-#if 0
-
-/* Not used.  */
-
-void
-lang_for_each_input_section (void (*func) (bfd *ab, asection *as))
-{
-  LANG_FOR_EACH_INPUT_STATEMENT (f)
-    {
-      asection *s;
-
-      for (s = f->the_bfd->sections; s != NULL; s = s->next)
-	func (f->the_bfd, s);
-    }
-}
-
-#endif
-
 void
 ldlang_add_file (lang_input_statement_type *entry)
 {
diff --git a/ld/ldlang.h b/ld/ldlang.h
index d518398..649fea1 100644
--- a/ld/ldlang.h
+++ b/ld/ldlang.h
@@ -264,6 +264,10 @@ typedef struct lang_input_statement_struct
   /* Whether to search for this entry as a dynamic archive.  */
   bfd_boolean dynamic;
 
+  /* Whether this entry should cause a DT_NEEDED tag only when
+     satisfying references from regular files, or always.  */
+  bfd_boolean as_needed;
+
   /* Whether to include the entire contents of an archive.  */
   bfd_boolean whole_archive;
 
diff --git a/ld/ldmain.c b/ld/ldmain.c
index 88b5c75..d0e0b12 100644
--- a/ld/ldmain.c
+++ b/ld/ldmain.c
@@ -1,6 +1,6 @@
 /* Main program of GNU linker.
    Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
-   2002, 2003
+   2002, 2003, 2004
    Free Software Foundation, Inc.
    Written by Steve Chamberlain steve@cygnus.com
 
@@ -93,6 +93,10 @@ bfd_boolean version_printed;
 /* Nonzero means link in every member of an archive.  */
 bfd_boolean whole_archive;
 
+/* Nonzero means create DT_NEEDED entries only if a dynamic library
+   actually satisfies some reference in a regular object.  */
+bfd_boolean as_needed;
+
 /* TRUE if we should demangle symbol names.  */
 bfd_boolean demangling;
 
diff --git a/ld/ldmain.h b/ld/ldmain.h
index 10169dd..8cab5fe 100644
--- a/ld/ldmain.h
+++ b/ld/ldmain.h
@@ -1,5 +1,5 @@
 /* ldmain.h -
-   Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1999, 2002, 2003
+   Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1999, 2002, 2003, 2004
    Free Software Foundation, Inc.
 
    This file is part of GLD, the Gnu Linker.
@@ -32,6 +32,7 @@ extern bfd_boolean trace_files;
 extern bfd_boolean trace_file_tries;
 extern bfd_boolean version_printed;
 extern bfd_boolean whole_archive;
+extern bfd_boolean as_needed;
 extern bfd_boolean demangling;
 extern int g_switch_value;
 extern const char *output_filename;
diff --git a/ld/lexsup.c b/ld/lexsup.c
index e43e15e..d3b3d8d 100644
--- a/ld/lexsup.c
+++ b/ld/lexsup.c
@@ -1,6 +1,6 @@
 /* Parse options for the GNU linker.
    Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
-   2001, 2002, 2003
+   2001, 2002, 2003, 2004
    Free Software Foundation, Inc.
 
    This file is part of GLD, the Gnu Linker.
@@ -112,6 +112,8 @@ enum option_values
   OPTION_SPLIT_BY_RELOC,
   OPTION_SPLIT_BY_FILE ,
   OPTION_WHOLE_ARCHIVE,
+  OPTION_AS_NEEDED,
+  OPTION_NO_AS_NEEDED,
   OPTION_WRAP,
   OPTION_FORCE_EXE_SUFFIX,
   OPTION_GC_SECTIONS,
@@ -438,6 +440,10 @@ static const struct ld_option ld_options[] =
      TWO_DASHES },
   { {"whole-archive", no_argument, NULL, OPTION_WHOLE_ARCHIVE},
       '\0', NULL, N_("Include all objects from following archives"), TWO_DASHES },
+  { {"as-needed", no_argument, NULL, OPTION_AS_NEEDED},
+      '\0', NULL, N_("Only set DT_NEEDED for following dynamic libs if used"), TWO_DASHES },
+  { {"no-as-needed", no_argument, NULL, OPTION_NO_AS_NEEDED},
+      '\0', NULL, N_("Always set DT_NEEDED for following dynamic libs"), TWO_DASHES },
   { {"wrap", required_argument, NULL, OPTION_WRAP},
       '\0', N_("SYMBOL"), N_("Use wrapper functions for SYMBOL"), TWO_DASHES }
 };
@@ -1156,6 +1162,12 @@ parse_args (unsigned argc, char **argv)
 	case OPTION_WHOLE_ARCHIVE:
 	  whole_archive = TRUE;
 	  break;
+	case OPTION_AS_NEEDED:
+	  as_needed = TRUE;
+	  break;
+	case OPTION_NO_AS_NEEDED:
+	  as_needed = FALSE;
+	  break;
 	case OPTION_WRAP:
 	  add_wrap (optarg);
 	  break;