From a2575bec2413d361c6ecfc4aecb2a31c86123f95 Mon Sep 17 00:00:00 2001
From: Cary Coutant <ccoutant@gmail.com>
Date: Fri, 22 Jun 2018 23:36:50 -0700
Subject: Update support for .note.gnu.property sections.

The original patch did not give the target enough hooks to discover that
an input object file does not have a particular property. For the
GNU_PROPERTY_X86_FEATURE_1_AND property, for example, where a missing
property should be assumed to be all zeroes, and ANDed with other
object modules, this is essential. We now store the target-specific
properties locally in the Target structure as native uint32_t fields,
then AND the per-object feature bits with the program's feature bits
when we're finished processing each input object file. The target-specific
properties are then added back to the output note section during
finalization.

gold/
	PR gold/22914
	* layout.cc (read_sized_value): Fix spelling of section name.
	(Layout::layout_gnu_property): Call Sized_target::record_gnu_property
	for target-specific properties;
	don't store them with target-independent properties yet.
	(Layout::merge_gnu_properties): New method.
	(Layout::add_gnu_property): New method.
	(Layout::create_gnu_properties_note): Call target to finalize
	target-specific properties. Fix spelling of output section name.
	* layout.h (Layout::merge_gnu_properties): New method.
	(Layout::add_gnu_property): New method.
	* object.cc (Sized_relobj_file::do_layout): Call
	Layout::merge_gnu_properties.
	* target.h (Target::merge_gnu_property): Remove.
	(Target::finalize_gnu_properties): New method.
	(Target::do_merge_gnu_property): Move to Sized_target and rename.
	(Target::do_finalize_gnu_properties): New virtual method.
	(Sized_target::record_gnu_property): Moved and renamed from
	Target::do_merge_gnu_property.
	(Sized_target::merge_gnu_properties): New virtual method.
	* x86_64.cc (Target_x86_64::isa_1_used_, isa_1_needed_)
	(feature_1_, object_feature_1_, seen_first_object_): New data members.
	(Target_x86_64::do_merge_gnu_property): Rename to ...
	(Target_x86_64::record_gnu_property): ... this.  Save target-specific
	properties in Target class object.
	(Target_x86_64::merge_gnu_properties): New method.
	(add_property): New static inline function.
	(Target_x86_64::do_finalize_gnu_properties): New method.
	* testsuite/Makefile.am (gnu_property_test): Remove C source file;
	link directly without compiler driver.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/gnu_property_a.S: Add _start.
---
 gold/target.h | 35 ++++++++++++++++-------------------
 1 file changed, 16 insertions(+), 19 deletions(-)

(limited to 'gold/target.h')

diff --git a/gold/target.h b/gold/target.h
index 1f8f757..bb31206 100644
--- a/gold/target.h
+++ b/gold/target.h
@@ -509,22 +509,10 @@ class Target
   should_include_section(elfcpp::Elf_Word sh_type) const
   { return this->do_should_include_section(sh_type); }
 
-  // Merge a target-specific program property in the .note.gnu.properties
-  // section.
+  // Finalize the target-specific properties in the .note.gnu.property section.
   void
-  merge_gnu_property(int note_type,
-		     int pr_type,
-		     size_t new_pr_datasz,
-		     const unsigned char* new_pr_data,
-		     size_t old_pr_datasz,
-		     unsigned char* old_pr_data,
-		     const Object* object) const
-  {
-    return this->do_merge_gnu_property(note_type, pr_type,
-				       new_pr_datasz, new_pr_data,
-				       old_pr_datasz, old_pr_data,
-				       object);
-  }
+  finalize_gnu_properties(Layout* layout) const
+  { this->do_finalize_gnu_properties(layout); }
 
  protected:
   // This struct holds the constant information for a child class.  We
@@ -832,11 +820,9 @@ class Target
   do_should_include_section(elfcpp::Elf_Word) const
   { return true; }
 
-  // Merge a target-specific program property in the .note.gnu.properties
-  // section.
+  // Finalize the target-specific properties in the .note.gnu.property section.
   virtual void
-  do_merge_gnu_property(int, int, size_t, const unsigned char*,
-			size_t, unsigned char*, const Object*) const
+  do_finalize_gnu_properties(Layout*) const
   { }
 
  private:
@@ -1158,6 +1144,17 @@ class Sized_target : public Target
     return elfcpp::elf_r_sym<size>(rel.get_r_info());
   }
 
+  // Record a target-specific program property in the .note.gnu.property
+  // section.
+  virtual void
+  record_gnu_property(int, int, size_t, const unsigned char*, const Object*)
+  { }
+
+  // Merge the target-specific program properties from the current object.
+  virtual void
+  merge_gnu_properties(const Object*)
+  { }
+
  protected:
   Sized_target(const Target::Target_info* pti)
     : Target(pti)
-- 
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