Add support for .note.gnu.property sections.

elfcpp/
	PR gold/22914
	* elfcpp.h (NT_GNU_PROPERTY_TYPE_0): New note type.
	(GNU_PROPERTY_*): New Gnu property types.
	* x86_64.h (GNU_PROPERTY_X86_FEATURE_1_IBT)
	(GNU_PROPERTY_X86_FEATURE_1_SHSTK): New x86 feature bits.

gold/
	PR gold/22914
	* layout.cc (Layout::Layout): Initialize gnu_properties_.
	(read_sized_value, write_sized_value): New functions.
	(Layout::layout_gnu_property): New method.
	(Layout::create_notes): Call create_gnu_properties_note.
	(Layout::create_gnu_properties_note): New method.
	* layout.h (Layout::layout_gnu_property): New method.
	(Layout::create_gnu_properties_note): New method.
	(Layout::Gnu_property, Layout::Gnu_properties): New types.
	(Layout::gnu_properties_): New data member.
	* object.cc (Sized_relobj_file::layout_gnu_property_section): New
	method.
	(Sized_relobj_file::do_layout): Handle .note.gnu.property sections.
	* object.h (Sized_relobj_file::layout_gnu_property_section): New
	method.
	* target.h (Target::merge_gnu_property): New method.
	(Target::do_merge_gnu_property): New virtual method.
	* x86_64.cc (Target_x86_64::do_merge_gnu_property): New method.
	* testsuite/Makefile.am (gnu_property_test): New test case.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/gnu_property_a.S: New source file.
	* testsuite/gnu_property_b.S: New source file.
	* testsuite/gnu_property_c.S: New source file.
	* testsuite/gnu_property_main.c: New source file.
	* testsuite/gnu_property_test.sh: New test script.

1 files changed, 39 insertions, 0 deletions

diff --git a/gold/x86_64.cc b/gold/x86_64.cc
index 603ac30..e6fa47e 100644
--- a/gold/x86_64.cc
+++ b/gold/x86_64.cc
@@ -1188,6 +1188,12 @@ class Target_x86_64 : public Sized_target<size, false>
 				  this->rela_dyn_section(layout));
   }
 
+  // Merge a target-specific program property in the .note.gnu.properties
+  // section.
+  void
+  do_merge_gnu_property(int, int, size_t, const unsigned char*,
+			size_t, unsigned char*, const Object*) const;
+
   // Information about this specific target which we pass to the
   // general Target structure.
   static const Target::Target_info x86_64_info;
@@ -1433,6 +1439,39 @@ Target_x86_64<size>::rela_irelative_section(Layout* layout)
   return this->rela_irelative_;
 }
 
+// Merge a target-specific program property in the .note.gnu.properties
+// section.
+template<int size>
+void
+Target_x86_64<size>::do_merge_gnu_property(
+    int, 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*) const
+{
+  size_t min_datasz = (new_pr_datasz > old_pr_datasz
+		       ? old_pr_datasz
+		       : new_pr_datasz);
+  switch (pr_type)
+    {
+    case elfcpp::GNU_PROPERTY_X86_ISA_1_USED:
+    case elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED:
+      {
+        for (size_t i = 0; i < min_datasz; ++i)
+          old_pr_data[i] |= new_pr_data[i];
+      }
+      break;
+    case elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND:
+      {
+        for (size_t i = 0; i < min_datasz; ++i)
+          old_pr_data[i] &= new_pr_data[i];
+      }
+      break;
+    default:
+      break;
+    }
+}
+
 // Write the first three reserved words of the .got.plt section.
 // The remainder of the section is written while writing the PLT
 // in Output_data_plt_i386::do_write.