Fix the behaviour of --allow-shlib-undefined, so that it does what it claims

to do.  Add an inverse switch.  Update the documentation.

4 files changed, 40 insertions, 16 deletions

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 807758c..431345f 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,11 @@
+2003-02-17  Nick Clifton  <nickc@redhat.com>
+
+	* ldmain.c (main) Default allow_shlib_undefined to true.
+        * lexsup.c (ld_options): Add --no-allow-shlib-undefined.
+        (parse_args): Parse the new switch.
+        * ld.texinfo: Document new switch and default behaviour of
+        allowing undefined symbols in shared libraries.
+
 2003-02-11 Dmitry Diky  <diwil@mail.ru>
 
 	* scripttempl/elf32msp430.sc: Add new data anchors definitions.
diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index 412ea88..0255662 100644
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -1108,8 +1108,10 @@ while linking a large executable.
 @item --no-undefined
 @itemx -z defs
 Normally when creating a non-symbolic shared library, undefined symbols
-are allowed and left to be resolved by the runtime loader.  These options
-disallows such undefined symbols.
+are allowed and left to be resolved by the runtime loader.  This option
+disallows such undefined symbols if they come from regular object
+files.  The switch @samp{--no-allow-shlib-undefined} controls the
+behaviour for shared objects being linked into the shared library.
 
 @kindex --allow-multiple-definition
 @kindex -z muldefs
@@ -1120,17 +1122,25 @@ report a fatal error. These options allow multiple definitions and the
 first definition will be used.
 
 @kindex --allow-shlib-undefined
+@kindex --no-allow-shlib-undefined
 @item --allow-shlib-undefined
-Allow undefined symbols in shared objects even  when --no-undefined is
-set. The net result will be that undefined symbols in regular objects
-will still trigger an error, but undefined symbols in shared objects
-will be ignored.  The implementation of no_undefined makes the
-assumption that the runtime linker will choke on undefined symbols.
-However there is at least one system (BeOS) where undefined symbols in
-shared libraries is normal since the kernel patches them at load time to
-select which function is most appropriate for the current architecture.
-I.E. dynamically select an appropriate memset function.  Apparently it
-is also normal for HPPA shared libraries to have undefined symbols.
+@itemx --no-allow-shlib-undefined
+Allow (the default) or disallow undefined symbols in shared objects.
+The setting of this switch overrides @samp {--no-undefined} where
+shared objects are concerned.  Thus if @samp {--no-undefined} is set
+but @samp {--no-allow-shlib-undefined} is not, the net result will be
+that undefined symbols in regular object files will trigger an error,
+but undefined symbols in shared objects will be ignored.
+
+The reason that @samp{--allow-shlib-undefined} is the default is that
+the shared object being specified at link time may not be the same one
+that is available at load time, so the symbols might actually be
+resolvable at load time.  Plus there are some systems, (eg BeOS) where
+undefined symbols in shared libraries is normal since the kernel
+patches them at load time to select which function is most appropriate
+for the current architecture. eg. to dynamically select an appropriate
+memset function.  Apparently it is also normal for HPPA shared
+libraries to have undefined symbols.
 
 @kindex --no-undefined-version
 @item --no-undefined-version
diff --git a/ld/ldmain.c b/ld/ldmain.c
index 9be3711..3aaef5d 100644
--- a/ld/ldmain.c
+++ b/ld/ldmain.c
@@ -265,7 +265,7 @@ main (argc, argv)
   link_info.traditional_format = FALSE;
   link_info.optimize = FALSE;
   link_info.no_undefined = FALSE;
-  link_info.allow_shlib_undefined = FALSE;
+  link_info.allow_shlib_undefined = TRUE;
   link_info.allow_multiple_definition = FALSE;
   link_info.allow_undefined_version = TRUE;
   link_info.keep_memory = TRUE;
diff --git a/ld/lexsup.c b/ld/lexsup.c
index 87a729a..8102f4e 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
+   2001, 2002, 2003
    Free Software Foundation, Inc.
 
    This file is part of GLD, the Gnu Linker.
@@ -126,7 +126,8 @@ int parsing_defsym = 0;
 #define OPTION_UNIQUE			(OPTION_SECTION_START + 1)
 #define OPTION_TARGET_HELP              (OPTION_UNIQUE + 1)
 #define OPTION_ALLOW_SHLIB_UNDEFINED	(OPTION_TARGET_HELP + 1)
-#define OPTION_ALLOW_MULTIPLE_DEFINITION (OPTION_ALLOW_SHLIB_UNDEFINED + 1)
+#define OPTION_NO_ALLOW_SHLIB_UNDEFINED	(OPTION_ALLOW_SHLIB_UNDEFINED + 1)
+#define OPTION_ALLOW_MULTIPLE_DEFINITION (OPTION_NO_ALLOW_SHLIB_UNDEFINED + 1)
 #define OPTION_NO_UNDEFINED_VERSION	(OPTION_ALLOW_MULTIPLE_DEFINITION + 1)
 #define OPTION_DISCARD_NONE		(OPTION_NO_UNDEFINED_VERSION + 1)
 #define OPTION_SPARE_DYNAMIC_TAGS	(OPTION_DISCARD_NONE + 1)
@@ -335,7 +336,9 @@ static const struct ld_option ld_options[] =
   { {"no-undefined", no_argument, NULL, OPTION_NO_UNDEFINED},
      '\0', NULL, N_("Allow no undefined symbols"), TWO_DASHES },
   { {"allow-shlib-undefined", no_argument, NULL, OPTION_ALLOW_SHLIB_UNDEFINED},
-     '\0', NULL, N_("Allow undefined symbols in shared objects"), TWO_DASHES },
+     '\0', NULL, N_("Allow undefined symbols in shared objects (the default)"), TWO_DASHES },
+  { {"no-allow-shlib-undefined", no_argument, NULL, OPTION_NO_ALLOW_SHLIB_UNDEFINED},
+     '\0', NULL, N_("Do not allow undefined symbols in shared objects"), TWO_DASHES },
   { {"allow-multiple-definition", no_argument, NULL, OPTION_ALLOW_MULTIPLE_DEFINITION},
      '\0', NULL, N_("Allow multiple definitions"), TWO_DASHES },
   { {"no-undefined-version", no_argument, NULL, OPTION_NO_UNDEFINED_VERSION},
@@ -788,6 +791,9 @@ parse_args (argc, argv)
 	case OPTION_ALLOW_SHLIB_UNDEFINED:
 	  link_info.allow_shlib_undefined = TRUE;
 	  break;
+	case OPTION_NO_ALLOW_SHLIB_UNDEFINED:
+	  link_info.allow_shlib_undefined = FALSE;
+	  break;
 	case OPTION_ALLOW_MULTIPLE_DEFINITION:
 	  link_info.allow_multiple_definition = TRUE;
 	  break;