x86: Properly merge GNU_PROPERTY_X86_ISA_1_USED

Without the GNU_PROPERTY_X86_ISA_1_USED property, all ISAs may be used.
If a bit in the GNU_PROPERTY_X86_ISA_1_USED property is unset, the
corresponding x86 instruction set isn’t used.  When merging properties
from 2 input files and one input file doesn't have the
GNU_PROPERTY_X86_ISA_1_USED property, the output file shouldn't have
it neither.  This patch removes the GNU_PROPERTY_X86_ISA_1_USED
property if an input file doesn't have it.

This patch replaces the GNU_PROPERTY_X86_ISA_1_USED property with the
GNU_PROPERTY_X86_ISA_1_NEEDED property which is the minimum ISA
requirement.

bfd/

	PR ld/23486
	* elfxx-x86.c (_bfd_x86_elf_merge_gnu_properties): Remove
	GNU_PROPERTY_X86_ISA_1_USED if an input file doesn't have it.
	(_bfd_x86_elf_link_setup_gnu_properties): Adding the
	GNU_PROPERTY_X86_ISA_1_NEEDED, instead of
	GNU_PROPERTY_X86_ISA_1_USED, property.

ld/

	PR ld/23486
	* testsuite/ld-i386/i386.exp: Run PR ld/23486 tests.
	* testsuite/ld-x86-64/x86-64.exp: Likewise.
	* testsuite/ld-i386/pr23486a.d: New file.
	* testsuite/ld-i386/pr23486b.d: Likewise.
	* testsuite/ld-x86-64/pr23486a-x32.d: Likewise.
	* testsuite/ld-x86-64/pr23486a.d: Likewise.
	* testsuite/ld-x86-64/pr23486a.s: Likewise.
	* testsuite/ld-x86-64/pr23486b-x32.d: Likewise.
	* testsuite/ld-x86-64/pr23486b.d: Likewise.
	* testsuite/ld-x86-64/pr23486b.s: Likewise.
	* testsuite/ld-i386/property-3.r: Remove "x86 ISA used".
	* testsuite/ld-i386/property-4.r: Likewise.
	* testsuite/ld-i386/property-5.r: Likewise.
	* testsuite/ld-i386/property-x86-ibt3a.d: Likewise.
	* testsuite/ld-i386/property-x86-ibt3b.d: Likewise.
	* testsuite/ld-i386/property-x86-shstk3a.d: Likewise.
	* testsuite/ld-i386/property-x86-shstk3b.d: Likewise.
	* testsuite/ld-x86-64/property-3.r: Likewise.
	* testsuite/ld-x86-64/property-4.r: Likewise.
	* testsuite/ld-x86-64/property-5.r: Likewise.
	* testsuite/ld-x86-64/property-x86-ibt3a-x32.d: Likewise.
	* testsuite/ld-x86-64/property-x86-ibt3a.d: Likewise.
	* testsuite/ld-x86-64/property-x86-ibt3b-x32.d: Likewise.
	* testsuite/ld-x86-64/property-x86-ibt3b.d: Likewise.
	* testsuite/ld-x86-64/property-x86-shstk3a-x32.d: Likewise.
	* testsuite/ld-x86-64/property-x86-shstk3a.d: Likewise.
	* testsuite/ld-x86-64/property-x86-shstk3b-x32.d: Likewise.
	* testsuite/ld-x86-64/property-x86-shstk3b.d: Likewise.

2 files changed, 29 insertions, 5 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index b16353f..dfa305d 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,12 @@
+2018-08-08  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/23486
+	* elfxx-x86.c (_bfd_x86_elf_merge_gnu_properties): Remove
+	GNU_PROPERTY_X86_ISA_1_USED if an input file doesn't have it.
+	(_bfd_x86_elf_link_setup_gnu_properties): Adding the
+	GNU_PROPERTY_X86_ISA_1_NEEDED, instead of
+	GNU_PROPERTY_X86_ISA_1_USED, property.
+
 2018-08-07  Alan Modra  <amodra@gmail.com>
 
 	* elf64-ppc.c (struct map_stub): Delete tls_get_addr_opt_bctrl.
diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c
index 2e4ff88..7ccfd25 100644
--- a/bfd/elfxx-x86.c
+++ b/bfd/elfxx-x86.c
@@ -2407,12 +2407,27 @@ _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
   switch (pr_type)
     {
     case GNU_PROPERTY_X86_ISA_1_USED:
+      if (aprop == NULL || bprop == NULL)
+	{
+	  /* Only one of APROP and BPROP can be NULL.  */
+	  if (aprop != NULL)
+	    {
+	      /* Remove this property since the other input file doesn't
+		 have it.  */
+	      aprop->pr_kind = property_remove;
+	      updated = TRUE;
+	    }
+	  break;
+	}
+      goto or_property;
+
     case GNU_PROPERTY_X86_ISA_1_NEEDED:
       if (aprop != NULL && bprop != NULL)
 	{
+or_property:
 	  number = aprop->u.number;
 	  aprop->u.number = number | bprop->u.number;
-	  /* Remove the property if ISA bits are empty.  */
+	  /* Remove the property if all bits are empty.  */
 	  if (aprop->u.number == 0)
 	    {
 	      aprop->pr_kind = property_remove;
@@ -2428,14 +2443,14 @@ _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info,
 	    {
 	      if (aprop->u.number == 0)
 		{
-		  /* Remove APROP if ISA bits are empty.  */
+		  /* Remove APROP if all bits are empty.  */
 		  aprop->pr_kind = property_remove;
 		  updated = TRUE;
 		}
 	    }
 	  else
 	    {
-	      /* Return TRUE if APROP is NULL and ISA bits of BPROP
+	      /* Return TRUE if APROP is NULL and all bits of BPROP
 		 aren't empty to indicate that BPROP should be added
 		 to ABFD.  */
 	      updated = bprop->u.number != 0;
@@ -2582,9 +2597,9 @@ _bfd_x86_elf_link_setup_gnu_properties
 	{
 	  /* If the separate code program header is needed, make sure
 	     that the first read-only PT_LOAD segment has no code by
-	     adding a GNU_PROPERTY_X86_ISA_1_USED note.  */
+	     adding a GNU_PROPERTY_X86_ISA_1_NEEDED note.  */
 	  prop = _bfd_elf_get_property (ebfd,
-					GNU_PROPERTY_X86_ISA_1_USED,
+					GNU_PROPERTY_X86_ISA_1_NEEDED,
 					4);
 	  prop->u.number = GNU_PROPERTY_X86_ISA_1_486;
 	  prop->pr_kind = property_number;