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[PATCH] Support anonymous versions in version scripts
- From: Jakub Jelinek <jakub at redhat dot com>
- To: binutils at sources dot redhat dot com
- Date: Wed, 12 Dec 2001 22:23:48 +0100
- Subject: [PATCH] Support anonymous versions in version scripts
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
The following patch adds anonymous version nodes (per Ulrich's request
anonymous version nodes are allowed only if there are no other nodes in the
version script).
Thus one can write:
x.map
{ global: foo; bar; local: *; };
-Wl,--version-script,x.map
and have all but foo and bar symbols not visible in .dynsym.
Ok to commit?
2001-12-12 Jakub Jelinek <jakub@redhat.com>
* ldgram.y (vers_node): Support anonymous version tags.
* ldlang.c (lang_register_vers_node): Ensure anonymous version
tag is not defined together with non-anonymous versions.
* ld.texinfo: Document it.
* elflink.h (size_dynamic_sections): Skip anonymous version tag.
(elf_link_assign_sym_version): Don't count anonymous version tag.
--- bfd/elflink.h.jj Wed Dec 12 20:10:29 2001
+++ bfd/elflink.h Wed Dec 12 22:57:17 2001
@@ -3179,6 +3179,10 @@ NAME(bfd_elf,size_dynamic_sections) (out
just linking a regular application. */
verdefs = asvinfo.verdefs;
+ /* Skip anonymous version tag. */
+ if (verdefs != NULL && verdefs->vernum == 0)
+ verdefs = verdefs->next;
+
if (verdefs == NULL)
_bfd_strip_section_from_output (info, s);
else
@@ -4241,6 +4245,9 @@ elf_link_assign_sym_version (h, data)
t->used = true;
version_index = 1;
+ /* Don't count anonymous version tag. */
+ if (sinfo->verdefs != NULL && sinfo->verdefs->vernum == 0)
+ version_index = 0;
for (pp = &sinfo->verdefs; *pp != NULL; pp = &(*pp)->next)
++version_index;
t->vernum = version_index;
--- ld/ldgram.y.jj Tue Nov 13 18:26:43 2001
+++ ld/ldgram.y Wed Dec 12 22:13:05 2001
@@ -1061,7 +1061,11 @@ vers_nodes:
;
vers_node:
- VERS_TAG '{' vers_tag '}' ';'
+ '{' vers_tag '}' ';'
+ {
+ lang_register_vers_node (NULL, $2, NULL);
+ }
+ | VERS_TAG '{' vers_tag '}' ';'
{
lang_register_vers_node ($1, $3, NULL);
}
--- ld/ldlang.c.jj Thu Nov 22 11:05:04 2001
+++ ld/ldlang.c Wed Dec 12 22:48:39 2001
@@ -5031,6 +5031,16 @@ lang_register_vers_node (name, version,
struct bfd_elf_version_tree *t, **pp;
struct bfd_elf_version_expr *e1;
+ if (name == NULL)
+ name = "";
+
+ if ((name[0] == '\0' && lang_elf_version_info != NULL)
+ || (lang_elf_version_info && lang_elf_version_info->name[0] == '\0'))
+ {
+ einfo (_("%X%P: anonymous version tag cannot be combined with other version tags\n"));
+ return;
+ }
+
/* Make sure this node has a unique name. */
for (t = lang_elf_version_info; t != NULL; t = t->next)
if (strcmp (t->name, name) == 0)
@@ -5067,8 +5077,13 @@ lang_register_vers_node (name, version,
version->deps = deps;
version->name = name;
- ++version_index;
- version->vernum = version_index;
+ if (name[0] != '\0')
+ {
+ ++version_index;
+ version->vernum = version_index;
+ }
+ else
+ version->vernum = 0;
for (pp = &lang_elf_version_info; *pp != NULL; pp = &(*pp)->next)
;
--- ld/ld.texinfo.jj Tue Nov 13 18:26:43 2001
+++ ld/ld.texinfo Wed Dec 12 23:32:34 2001
@@ -3685,6 +3685,15 @@ they might suggest to the person reading
could just as well have appeared in between @samp{1.1} and @samp{1.2}.
However, this would be a confusing way to write a version script.
+Node name can be ommited, provided it is the only version node
+in the version script. Such version script doesn't assign any versions to
+symbols, only selects which symbols will be globally visible out and which
+won't.
+
+@smallexample
+@{ global: foo; bar; local: *; @}
+#end smallexample
+
When you link an application against a shared library that has versioned
symbols, the application itself knows which version of each symbol it
requires, and it also knows which version nodes it needs from each
Jakub