From 3728821ffcf74858b028948e224e1dc4695d9112 Mon Sep 17 00:00:00 2001
From: Ian Lance Taylor <iant@google.com>
Date: Wed, 14 Nov 2007 07:52:21 +0000
Subject: Support special always-defined symbols for targets.

---
 gold/i386.cc   |  5 +++++
 gold/symtab.cc |  3 ++-
 gold/target.h  | 13 +++++++++++++
 gold/x86_64.cc |  5 +++++
 4 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/gold/i386.cc b/gold/i386.cc
index eae6b7f..9b90c79 100644
--- a/gold/i386.cc
+++ b/gold/i386.cc
@@ -84,6 +84,11 @@ class Target_i386 : public Sized_target<32, false>
   uint64_t
   do_dynsym_value(const Symbol*) const;
 
+  // Return whether SYM is always defined.
+  bool
+  do_is_always_defined(Symbol* sym) const
+  { return strcmp(sym->name(), "___tls_get_addr") == 0; }
+
   // Relocate a section.
   void
   relocate_section(const Relocate_info<32, false>*,
diff --git a/gold/symtab.cc b/gold/symtab.cc
index f5e2132..2443023 100644
--- a/gold/symtab.cc
+++ b/gold/symtab.cc
@@ -1610,7 +1610,8 @@ Symbol_table::sized_write_globals(const Target* target,
           && sym->object()->is_dynamic()
           && sym->shndx() == elfcpp::SHN_UNDEF
 	  && sym->binding() != elfcpp::STB_WEAK
-	  && !parameters->allow_shlib_undefined())
+	  && !parameters->allow_shlib_undefined()
+	  && !target->is_always_defined(sym))
 	{
 	  // A very ugly cast.
 	  Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
diff --git a/gold/target.h b/gold/target.h
index 8ecc078..33c351c 100644
--- a/gold/target.h
+++ b/gold/target.h
@@ -137,6 +137,13 @@ class Target
   code_fill(off_t length)
   { return this->do_code_fill(length); }
 
+  // Return whether SYM is a special symbol which is known to be
+  // defined.  This is used to avoid inappropriate warnings about
+  // undefined symbols.
+  bool
+  is_always_defined(Symbol* sym) const
+  { return this->do_is_always_defined(sym); }
+
  protected:
   // This struct holds the constant information for a child class.  We
   // use a struct to avoid the overhead of virtual function calls for
@@ -188,6 +195,12 @@ class Target
   do_code_fill(off_t)
   { gold_unreachable(); }
 
+  // Virtual function which may be implemented by the child class if
+  // needed.
+  virtual bool
+  do_is_always_defined(Symbol*) const
+  { return false; }
+
  private:
   Target(const Target&);
   Target& operator=(const Target&);
diff --git a/gold/x86_64.cc b/gold/x86_64.cc
index 0614e89..ead93d9 100644
--- a/gold/x86_64.cc
+++ b/gold/x86_64.cc
@@ -97,6 +97,11 @@ class Target_x86_64 : public Sized_target<64, false>
   uint64_t
   do_dynsym_value(const Symbol*) const;
 
+  // Return whether SYM is always defined.
+  bool
+  do_is_always_defined(Symbol* sym) const
+  { return strcmp(sym->name(), "__tls_get_addr") == 0; }
+
   // Relocate a section.
   void
   relocate_section(const Relocate_info<64, false>*,
-- 
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