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[PATCH] gold: Don't rescan for undefined symbols in dynamic objects
- From: Stephen Crane <sjc at immunant dot com>
- To: binutils at sourceware dot org
- Date: Fri, 17 Nov 2017 13:58:43 -0800
- Subject: [PATCH] gold: Don't rescan for undefined symbols in dynamic objects
- Authentication-results: sourceware.org; auth=none
I ran into a bug when mixing LTO and linking against shared
libraries. If a shared library contains an undefined symbol and LTO adds
a new reference to that same undefined symbol, the reference in the new
object added by the plugin would not trigger a rescan of the archive
containing the symbol. Full bug report:
https://sourceware.org/bugzilla/show_bug.cgi?id=22448
Here is a proposed fix, does this look good? Thanks!
gold/ChangeLog:
2017-11-17 Stephen Crane <sjc@immunant.com>
PR gold/22448
* symtab.cc (Symbol_table::add_from_object): Only rescan for
undefined symbols in regular, not dynamic, objects.
diff --git a/gold/symtab.cc b/gold/symtab.cc
index d1f71e02d0..e50b42c43b 100644
--- a/gold/symtab.cc
+++ b/gold/symtab.cc
@@ -990,7 +990,7 @@ Symbol_table::add_from_object(Object* object,
// ins.second: true if new entry was inserted, false if not.
Sized_symbol<size>* ret;
- bool was_undefined;
+ bool was_undefined_in_reg;
bool was_common;
if (!ins.second)
{
@@ -998,7 +998,7 @@ Symbol_table::add_from_object(Object* object,
ret = this->get_sized_symbol<size>(ins.first->second);
gold_assert(ret != NULL);
- was_undefined = ret->is_undefined();
+ was_undefined_in_reg = ret->is_undefined() && ret->in_reg();
// Commons from plugins are just placeholders.
was_common = ret->is_common() && ret->object()->pluginobj() == NULL;
@@ -1049,7 +1049,7 @@ Symbol_table::add_from_object(Object* object,
// it, then change it to NAME/VERSION.
ret = this->get_sized_symbol<size>(insdefault.first->second);
- was_undefined = ret->is_undefined();
+ was_undefined_in_reg = ret->is_undefined() && ret->in_reg();
// Commons from plugins are just placeholders.
was_common = ret->is_common() && ret->object()->pluginobj() == NULL;
@@ -1061,7 +1061,7 @@ Symbol_table::add_from_object(Object* object,
}
else
{
- was_undefined = false;
+ was_undefined_in_reg = false;
was_common = false;
Sized_target<size, big_endian>* target =
@@ -1105,9 +1105,10 @@ Symbol_table::add_from_object(Object* object,
ret->set_is_default();
}
- // Record every time we see a new undefined symbol, to speed up
- // archive groups.
- if (!was_undefined && ret->is_undefined())
+ // Record every time we see a new undefined symbol, to speed up archive
+ // groups. We only care about symbols undefined in regular objects here
+ // because undefined symbols only in dynamic objects should't trigger rescans.
+ if (!was_undefined_in_reg && ret->is_undefined() && ret->in_reg())
{
++this->saw_undefined_;
if (parameters->options().has_plugins())