commit cd453cd072004d26ede355b850b3831acffaeddd

Author: Ulrich Weigand <ulrich.weigand@de.ibm.com>

Date:   Tue Feb 4 18:38:56 2014 +0100

    PowerPC64 ELFv2 ABI: base support

    This is the first patch of a series to implement support for the

    PowerPC ELFv2 ABI.  While powerpc64le-linux will use ELFv2, and

    the existing powerpc64-linux code will continue to use ELFv1,

    in theory ELFv2 is also defined for big-endian systems (and

    ELFv1 was also defined for little-endian systems).

    Therefore this patch adds a new tdep->elf_abi variable to decide

    which ABI version to use.  This is detected from the ELF header

    e_flags value; if this is not present, we default to ELFv2 on

    little-endian and ELFv1 otherwise.

    This patch does not yet introduce any actual difference in GDB's

    handling of the two ABIs.  Those will be added by the remainder

    of this patch series.

    For an overview of the changes in ELFv2, have a look at the

    comments in the patch series that added ELFv2 to GCC, starting at:

    http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01144.html

    gdb/ChangeLog:

    	* ppc-tdep.h (enum powerpc_elf_abi): New data type.

    	(struct gdbarch_tdep): New member elf_abi.

    	* rs6000-tdep.c: Include "elf/ppc64.h".

    	(rs6000_gdbarch_init): Detect ELF ABI version.

Index: gdb-7.6.1/gdb/ppc-tdep.h

===================================================================

--- gdb-7.6.1.orig/gdb/ppc-tdep.h

+++ gdb-7.6.1/gdb/ppc-tdep.h

@@ -182,6 +182,15 @@ extern void ppc_collect_vsxregset (const

 /* Private data that this module attaches to struct gdbarch.  */

+/* ELF ABI version used by the inferior.  */

+enum powerpc_elf_abi

+{

+  POWERPC_ELF_AUTO,

+  POWERPC_ELF_V1,

+  POWERPC_ELF_V2,

+  POWERPC_ELF_LAST

+};

+

 /* Vector ABI used by the inferior.  */

 enum powerpc_vector_abi

 {

@@ -197,6 +206,8 @@ struct gdbarch_tdep

     int wordsize;		/* Size in bytes of fixed-point word.  */

     int soft_float;		/* Avoid FP registers for arguments?  */

+    enum powerpc_elf_abi elf_abi;	/* ELF ABI version.  */

+

     /* How to pass vector arguments.  Never set to AUTO or LAST.  */

     enum powerpc_vector_abi vector_abi;

Index: gdb-7.6.1/gdb/rs6000-tdep.c

===================================================================

--- gdb-7.6.1.orig/gdb/rs6000-tdep.c

+++ gdb-7.6.1/gdb/rs6000-tdep.c

@@ -48,6 +48,7 @@

 #include "elf-bfd.h"

 #include "elf/ppc.h"

+#include "elf/ppc64.h"

 #include "solib-svr4.h"

 #include "ppc-tdep.h"

@@ -3605,6 +3606,7 @@ rs6000_gdbarch_init (struct gdbarch_info

   enum auto_boolean soft_float_flag = powerpc_soft_float_global;

   int soft_float;

   enum powerpc_vector_abi vector_abi = powerpc_vector_abi_global;

+  enum powerpc_elf_abi elf_abi = POWERPC_ELF_AUTO;

   int have_fpu = 1, have_spe = 0, have_mq = 0, have_altivec = 0, have_dfp = 0,

       have_vsx = 0;

   int tdesc_wordsize = -1;

@@ -3911,6 +3913,21 @@ rs6000_gdbarch_init (struct gdbarch_info

     }

 #ifdef HAVE_ELF

+  if (from_elf_exec)

+    {

+      switch (elf_elfheader (info.abfd)->e_flags & EF_PPC64_ABI)

+	{

+	case 1:

+	  elf_abi = POWERPC_ELF_V1;

+	  break;

+	case 2:

+	  elf_abi = POWERPC_ELF_V2;

+	  break;

+	default:

+	  break;

+	}

+    }

+

   if (soft_float_flag == AUTO_BOOLEAN_AUTO && from_elf_exec)

     {

       switch (bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_GNU,

@@ -3947,6 +3964,21 @@ rs6000_gdbarch_init (struct gdbarch_info

     }

 #endif

+  /* At this point, the only supported ELF-based 64-bit little-endian

+     operating system is GNU/Linux, and this uses the ELFv2 ABI by

+     default.  All other supported ELF-based operating systems use the

+     ELFv1 ABI by default.  Therefore, if the ABI marker is missing,

+     e.g. because we run a legacy binary, or have attached to a process

+     and have not found any associated binary file, set the default

+     according to this heuristic.  */

+  if (elf_abi == POWERPC_ELF_AUTO)

+    {

+      if (wordsize == 8 && info.byte_order == BFD_ENDIAN_LITTLE)

+        elf_abi = POWERPC_ELF_V2;

+      else

+        elf_abi = POWERPC_ELF_V1;

+    }

+

   if (soft_float_flag == AUTO_BOOLEAN_TRUE)

     soft_float = 1;

   else if (soft_float_flag == AUTO_BOOLEAN_FALSE)

@@ -3989,6 +4021,8 @@ rs6000_gdbarch_init (struct gdbarch_info

          meaningful, because 64-bit CPUs can run in 32-bit mode.  So, perform

          separate word size check.  */

       tdep = gdbarch_tdep (arches->gdbarch);

+      if (tdep && tdep->elf_abi != elf_abi)

+	continue;

       if (tdep && tdep->soft_float != soft_float)

 	continue;

       if (tdep && tdep->vector_abi != vector_abi)

@@ -4011,6 +4045,7 @@ rs6000_gdbarch_init (struct gdbarch_info

   tdep = XCALLOC (1, struct gdbarch_tdep);

   tdep->wordsize = wordsize;

+  tdep->elf_abi = elf_abi;

   tdep->soft_float = soft_float;

   tdep->vector_abi = vector_abi;