Support PIE on Solaris 12

[Rainer Orth <ro at CeBiTec dot Uni-Bielefeld dot DE>]

As mentioned in

	https://gcc.gnu.org/ml/gcc-patches/2015-08/msg01389.html

Solaris 12 will gain support for Position Independent Executables
(PIE).  The following patch implements the changes to ld (and a minor
readelf addition) to handle this.  Effectively it's only setting the new
DF_1_PIE flag.

The patch was tested with an early version of the new PIC CRTs, the PIE
patch from the message above, and mainline gcc configured both without
and with --enable-default-pie.

Ok for mainline?

	Rainer

-- 
-----------------------------------------------------------------------------
Rainer Orth, Center for Biotechnology, Bielefeld University


2015-08-25  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	ld:
	* emulparams/solaris2.sh (GENERATE_PIE_SCRIPT): Set to yes.

	* emultempl/elf32.em (ld_${EMULATION_NAME}_emulation): Allow
	overriding gld${EMULATION_NAME}_handle_option.
	* emultempl/solaris2.em: Include ldlex.h.
	(gld${EMULATION_NAME}_handle_option): Declare.
	(elf_solaris2_handle_option): New function.
	(LDEMUL_HANDLE_OPTION): Uset it.

	include/elf:
	* common.h (DF_1_PIE): Define.

	binutils:
	* readelf.c (process_dynamic_section): Handle DF_1_PIE.

diff --git a/binutils/readelf.c b/binutils/readelf.c
--- a/binutils/readelf.c
+++ b/binutils/readelf.c
@@ -9234,6 +9234,11 @@ process_dynamic_section (FILE * file)
 		      printf (" SINGLETON");
 		      val ^= DF_1_SINGLETON;
 		    }
+		  if (val & DF_1_PIE)
+		    {
+		      printf (" PIE");
+		      val ^= DF_1_PIE;
+		    }
 		  if (val != 0)
 		    printf (" %lx", val);
 		  puts ("");
diff --git a/include/elf/common.h b/include/elf/common.h
--- a/include/elf/common.h
+++ b/include/elf/common.h
@@ -868,6 +868,8 @@
 #define	DF_1_GLOBAUDIT	0x01000000
 #define	DF_1_SINGLETON	0x02000000
 
+#define	DF_1_PIE	0x08000000
+
 /* Flag values for the DT_FLAGS entry.	*/
 #define DF_ORIGIN	(1 << 0)
 #define DF_SYMBOLIC	(1 << 1)
diff --git a/ld/emulparams/solaris2.sh b/ld/emulparams/solaris2.sh
--- a/ld/emulparams/solaris2.sh
+++ b/ld/emulparams/solaris2.sh
@@ -8,3 +8,5 @@
 # File, p.63.
 TEXT_START_SYMBOLS='_START_ = .;'
 OTHER_END_SYMBOLS='_END_ = .;'
+# Beginning with Solaris 12, there's PIE support.
+GENERATE_PIE_SCRIPT=yes
diff --git a/ld/emultempl/elf32.em b/ld/emultempl/elf32.em
--- a/ld/emultempl/elf32.em
+++ b/ld/emultempl/elf32.em
@@ -2463,7 +2463,7 @@ struct ld_emulation_xfer_struct ld_${EMU
   ${LDEMUL_SET_SYMBOLS-NULL},
   ${LDEMUL_PARSE_ARGS-NULL},
   gld${EMULATION_NAME}_add_options,
-  gld${EMULATION_NAME}_handle_option,
+  ${LDEMUL_HANDLE_OPTION-gld${EMULATION_NAME}_handle_option},
   ${LDEMUL_UNRECOGNIZED_FILE-NULL},
   ${LDEMUL_LIST_OPTIONS-${gld_list_options}},
   ${LDEMUL_RECOGNIZED_FILE-gld${EMULATION_NAME}_load_symbols},
diff --git a/ld/emultempl/solaris2.em b/ld/emultempl/solaris2.em
--- a/ld/emultempl/solaris2.em
+++ b/ld/emultempl/solaris2.em
@@ -29,6 +29,10 @@ fragment <<EOF
    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
    MA 02110-1301, USA.  */
 
+#include "ldlex.h"
+
+static bfd_boolean gld${EMULATION_NAME}_handle_option (int);
+
 #define TARGET_IS_${EMULATION_NAME}
 
 /* The Solaris 2 ABI requires some global symbols to be present in the
@@ -149,7 +153,21 @@ elf_solaris2_after_allocation (void)
   gld${EMULATION_NAME}_after_allocation ();
 }
 
+static bfd_boolean
+elf_solaris2_handle_option (int optc)
+{
+  if (optc == OPTION_PIE)
+    {
+      link_info.flags_1 |= (bfd_vma) DF_1_PIE;
+      /* Necessary to have lexsup.c (parse_args) do its work.  */
+      return FALSE;
+    }
+      
+  return gld${EMULATION_NAME}_handle_option (optc);
+}
+
 EOF
 
 LDEMUL_BEFORE_ALLOCATION=elf_solaris2_before_allocation
 LDEMUL_AFTER_ALLOCATION=elf_solaris2_after_allocation
+LDEMUL_HANDLE_OPTION=elf_solaris2_handle_option