[GDBserver] Centralize tdesc for i386-linux

tdesc_i386_XXX_linux is spread in linux-x86-low.c and this patch adds
a new function i386_get_ipa_tdesc to return the right tdesc according to
tdesc index.  Note that GDB has a similar function returning tdesc, but
with different argument.  Ultimately, GDB and GDBserver should share
this function.

gdb/gdbserver:

2017-06-07  Yao Qi  <yao.qi@linaro.org>

	* configure.srv (srv_tgtobj): Append linux-x86-tdesc.o.
	(ipa_obj): Likewise.
	* linux-i386-ipa.c (get_ipa_tdesc): Move it to
	linux-x86-tdesc.c.
	(initialize_low_tracepoint): Don't call  init_registers_XXX
	functions, call initialize_low_tdesc instead.
	* linux-x86-low.c (x86_linux_read_description): Call
	i386_get_ipa_tdesc.
	(initialize_low_arch): Don't call init_registers_i386_XXX
	functions, call initialize_low_tdesc.
	* linux-x86-tdesc.c: New file.
	* linux-x86-tdesc.h (x86_linux_tdesc): New X86_TDESC_LAST.
	(i386_get_ipa_tdesc_idx): Declare.
	(i386_get_ipa_tdesc): Declare.
	(initialize_low_tdesc): Declare.

5 files changed, 135 insertions, 93 deletions

diff --git a/gdb/gdbserver/configure.srv b/gdb/gdbserver/configure.srv
index 43f90c9..1a5801a 100644
--- a/gdb/gdbserver/configure.srv
+++ b/gdb/gdbserver/configure.srv
@@ -122,13 +122,14 @@ case "${target}" in
 			    srv_tgtobj="amd64-linux-siginfo.o"
 			fi
 			srv_tgtobj="${srv_tgtobj} $srv_linux_obj linux-x86-low.o x86-low.o x86-dregs.o i387-fp.o"
+			srv_tgtobj="${srv_tgtobj} linux-x86-tdesc.o"
 			srv_tgtobj="${srv_tgtobj} linux-btrace.o x86-linux.o"
 			srv_tgtobj="${srv_tgtobj} x86-linux-dregs.o"
 			srv_linux_usrregs=yes
 			srv_linux_regsets=yes
 			srv_linux_thread_db=yes
 			srv_linux_btrace=yes
-			ipa_obj="${ipa_i386_linux_regobj} linux-i386-ipa.o"
+			ipa_obj="${ipa_i386_linux_regobj} linux-i386-ipa.o linux-x86-tdesc-ipa.o"
 			;;
   i[34567]86-*-lynxos*)	srv_regobj="i386.o"
 			srv_tgtobj="lynx-low.o lynx-i386-low.o fork-child.o fork-inferior.o"
@@ -356,6 +357,7 @@ case "${target}" in
 			;;
   x86_64-*-linux*)	srv_regobj="$srv_amd64_linux_regobj $srv_i386_linux_regobj"
 			srv_tgtobj="$srv_linux_obj linux-x86-low.o x86-low.o x86-dregs.o i387-fp.o"
+			srv_tgtobj="${srv_tgtobj} linux-x86-tdesc.o"
 			srv_tgtobj="${srv_tgtobj} linux-btrace.o x86-linux.o"
 			srv_tgtobj="${srv_tgtobj} x86-linux-dregs.o"
 			srv_tgtobj="${srv_tgtobj} amd64-linux-siginfo.o"
@@ -369,7 +371,7 @@ case "${target}" in
 			else
 			    ipa_obj="${ipa_amd64_linux_regobj}"
 			fi
-			ipa_obj="${ipa_obj} linux-amd64-ipa.o"
+			ipa_obj="${ipa_obj} linux-amd64-ipa.o linux-x86-tdesc-ipa.o"
 			;;
   x86_64-*-mingw*)	srv_regobj="$srv_amd64_regobj"
 			srv_tgtobj="x86-low.o x86-dregs.o i387-fp.o win32-low.o win32-i386-low.o"
diff --git a/gdb/gdbserver/linux-i386-ipa.c b/gdb/gdbserver/linux-i386-ipa.c
index e9ac78b..bca3fdb 100644
--- a/gdb/gdbserver/linux-i386-ipa.c
+++ b/gdb/gdbserver/linux-i386-ipa.c
@@ -244,35 +244,6 @@ initialize_fast_tracepoint_trampoline_buffer (void)
     }
 }
 
-/* Return target_desc to use for IPA, given the tdesc index passed by
-   gdbserver.  */
-
-const struct target_desc *
-get_ipa_tdesc (int idx)
-{
-  switch (idx)
-    {
-    case X86_TDESC_MMX:
-      return tdesc_i386_mmx_linux;
-    case X86_TDESC_SSE:
-      return tdesc_i386_linux;
-    case X86_TDESC_AVX:
-      return tdesc_i386_avx_linux;
-    case X86_TDESC_MPX:
-      return tdesc_i386_mpx_linux;
-    case X86_TDESC_AVX_MPX:
-      return tdesc_i386_avx_mpx_linux;
-    case X86_TDESC_AVX_AVX512:
-      return tdesc_i386_avx_avx512_linux;
-    case X86_TDESC_AVX_MPX_AVX512_PKU:
-      return tdesc_i386_avx_mpx_avx512_pku_linux;
-    default:
-      internal_error (__FILE__, __LINE__,
-		      "unknown ipa tdesc index: %d", idx);
-      return tdesc_i386_linux;
-    }
-}
-
 /* Allocate buffer for the jump pads.  On i386, we can reach an arbitrary
    address with a jump instruction, so just allocate normally.  */
 
@@ -291,12 +262,7 @@ alloc_jump_pad_buffer (size_t size)
 void
 initialize_low_tracepoint (void)
 {
-  init_registers_i386_mmx_linux ();
-  init_registers_i386_linux ();
-  init_registers_i386_avx_linux ();
-  init_registers_i386_mpx_linux ();
-  init_registers_i386_avx_avx512_linux ();
-  init_registers_i386_avx_mpx_avx512_pku_linux ();
+  initialize_low_tdesc ();
 
   initialize_fast_tracepoint_trampoline_buffer ();
 }
diff --git a/gdb/gdbserver/linux-x86-low.c b/gdb/gdbserver/linux-x86-low.c
index b39026c..f5d4aa1 100644
--- a/gdb/gdbserver/linux-x86-low.c
+++ b/gdb/gdbserver/linux-x86-low.c
@@ -757,7 +757,7 @@ x86_linux_read_description (void)
 	{
 	  have_ptrace_getfpxregs = 0;
 	  have_ptrace_getregset = 0;
-	  return tdesc_i386_mmx_linux;
+	  return i386_get_ipa_tdesc (X86_TDESC_MMX);
 	}
       else
 	have_ptrace_getfpxregs = 1;
@@ -878,26 +878,26 @@ x86_linux_read_description (void)
 	  switch (xcr0 & X86_XSTATE_ALL_MASK)
 	    {
 	    case X86_XSTATE_AVX_MPX_AVX512_PKU_MASK:
-	      return tdesc_i386_avx_mpx_avx512_pku_linux;
+	      return i386_get_ipa_tdesc (X86_TDESC_AVX_MPX_AVX512_PKU);
 
 	    case (X86_XSTATE_AVX_AVX512_MASK):
-	      return tdesc_i386_avx_avx512_linux;
+	      return i386_get_ipa_tdesc (X86_TDESC_AVX_AVX512);
 
 	    case (X86_XSTATE_MPX_MASK):
-	      return tdesc_i386_mpx_linux;
+	      return i386_get_ipa_tdesc (X86_TDESC_MPX);
 
 	    case (X86_XSTATE_AVX_MPX_MASK):
-	      return tdesc_i386_avx_mpx_linux;
+	      return i386_get_ipa_tdesc (X86_TDESC_AVX_MPX);
 
 	    case (X86_XSTATE_AVX_MASK):
-	      return tdesc_i386_avx_linux;
+	      return i386_get_ipa_tdesc (X86_TDESC_AVX);
 
 	    default:
-	      return tdesc_i386_linux;
+	      return i386_get_ipa_tdesc (X86_TDESC_SSE);
 	    }
 	}
       else
-	return tdesc_i386_linux;
+	return i386_get_ipa_tdesc (X86_TDESC_SSE);
     }
 
   gdb_assert_not_reached ("failed to return tdesc");
@@ -2912,22 +2912,10 @@ x86_get_ipa_tdesc_idx (void)
     return X86_TDESC_AVX_AVX512;
 #endif
 
-  if (tdesc == tdesc_i386_mmx_linux)
-    return X86_TDESC_MMX;
-  if (tdesc == tdesc_i386_linux || tdesc == tdesc_i386_linux_no_xml)
+  if (tdesc == tdesc_i386_linux_no_xml)
     return X86_TDESC_SSE;
-  if (tdesc == tdesc_i386_avx_linux)
-    return X86_TDESC_AVX;
-  if (tdesc == tdesc_i386_mpx_linux)
-    return X86_TDESC_MPX;
-  if (tdesc == tdesc_i386_avx_mpx_linux)
-    return X86_TDESC_AVX_MPX;
-  if (tdesc == tdesc_i386_avx_mpx_avx512_pku_linux)
-    return X86_TDESC_AVX_MPX_AVX512_PKU;
-  if (tdesc == tdesc_i386_avx_avx512_linux)
-    return X86_TDESC_AVX_AVX512;
 
-  return 0;
+  return i386_get_ipa_tdesc_idx (tdesc);
 }
 
 /* This is initialized assuming an amd64 target.
@@ -2996,16 +2984,12 @@ initialize_low_arch (void)
   copy_target_description (tdesc_amd64_linux_no_xml, tdesc_amd64_linux);
   tdesc_amd64_linux_no_xml->xmltarget = xmltarget_amd64_linux_no_xml;
 #endif
-  init_registers_i386_linux ();
-  init_registers_i386_mmx_linux ();
-  init_registers_i386_avx_linux ();
-  init_registers_i386_mpx_linux ();
-  init_registers_i386_avx_mpx_linux ();
-  init_registers_i386_avx_avx512_linux ();
-  init_registers_i386_avx_mpx_avx512_pku_linux ();
+
+  initialize_low_tdesc ();
 
   tdesc_i386_linux_no_xml = XNEW (struct target_desc);
-  copy_target_description (tdesc_i386_linux_no_xml, tdesc_i386_linux);
+  copy_target_description (tdesc_i386_linux_no_xml,
+			   i386_get_ipa_tdesc (X86_TDESC_SSE));
   tdesc_i386_linux_no_xml->xmltarget = xmltarget_i386_linux_no_xml;
 
   initialize_regsets_info (&x86_regsets_info);
diff --git a/gdb/gdbserver/linux-x86-tdesc.c b/gdb/gdbserver/linux-x86-tdesc.c
new file mode 100644
index 0000000..e294a98
--- /dev/null
+++ b/gdb/gdbserver/linux-x86-tdesc.c
@@ -0,0 +1,111 @@
+/* GNU/Linux/x86-64 specific target description, for the remote server
+   for GDB.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "server.h"
+#include "linux-x86-tdesc.h"
+
+#if defined __i386__ || !defined IN_PROCESS_AGENT
+/* Defined in auto-generated file i386-linux.c.  */
+void init_registers_i386_linux (void);
+extern const struct target_desc *tdesc_i386_linux;
+
+/* Defined in auto-generated file i386-mmx-linux.c.  */
+void init_registers_i386_mmx_linux (void);
+extern const struct target_desc *tdesc_i386_mmx_linux;
+
+/* Defined in auto-generated file i386-avx-linux.c.  */
+void init_registers_i386_avx_linux (void);
+extern const struct target_desc *tdesc_i386_avx_linux;
+
+/* Defined in auto-generated file i386-avx-mpx-linux.c.  */
+void init_registers_i386_avx_mpx_linux (void);
+extern const struct target_desc *tdesc_i386_avx_mpx_linux;
+
+/* Defined in auto-generated file i386-avx-avx512-linux.c.  */
+void init_registers_i386_avx_avx512_linux (void);
+extern const struct target_desc *tdesc_i386_avx_avx512_linux;
+
+/* Defined in auto-generated file i386-avx-mpx-avx512-linux.c.  */
+void init_registers_i386_avx_mpx_avx512_pku_linux (void);
+extern const struct target_desc *tdesc_i386_avx_mpx_avx512_pku_linux;
+
+/* Defined in auto-generated file i386-mpx-linux.c.  */
+void init_registers_i386_mpx_linux (void);
+extern const struct target_desc *tdesc_i386_mpx_linux;
+#endif
+
+static const struct target_desc *i386_tdescs[X86_TDESC_LAST] = { };
+
+void
+initialize_low_tdesc ()
+{
+#if defined __i386__ || !defined IN_PROCESS_AGENT
+  init_registers_i386_linux ();
+  init_registers_i386_mmx_linux ();
+  init_registers_i386_avx_linux ();
+  init_registers_i386_mpx_linux ();
+  init_registers_i386_avx_mpx_linux ();
+  init_registers_i386_avx_avx512_linux ();
+  init_registers_i386_avx_mpx_avx512_pku_linux ();
+
+  i386_tdescs[X86_TDESC_MMX] = tdesc_i386_mmx_linux;
+  i386_tdescs[X86_TDESC_SSE] = tdesc_i386_linux;
+  i386_tdescs[X86_TDESC_AVX] = tdesc_i386_avx_linux;
+  i386_tdescs[X86_TDESC_MPX] = tdesc_i386_mpx_linux;
+  i386_tdescs[X86_TDESC_AVX_MPX] = tdesc_i386_avx_mpx_linux;
+  i386_tdescs[X86_TDESC_AVX_AVX512] = tdesc_i386_avx_avx512_linux;
+  i386_tdescs[X86_TDESC_AVX_MPX_AVX512_PKU]
+    = tdesc_i386_avx_mpx_avx512_pku_linux;
+#endif
+}
+
+const struct target_desc *
+i386_get_ipa_tdesc (int idx)
+{
+  if (idx >= X86_TDESC_LAST)
+    internal_error (__FILE__, __LINE__,
+		    "unknown ipa tdesc index: %d", idx);
+
+  return i386_tdescs[idx];
+}
+
+#ifdef IN_PROCESS_AGENT
+
+#if defined __i386__
+const struct target_desc *
+get_ipa_tdesc (int idx)
+{
+return i386_get_ipa_tdesc (idx);
+}
+#endif
+
+#else
+int
+i386_get_ipa_tdesc_idx (const struct target_desc *tdesc)
+{
+  for (int i = 0; i < X86_TDESC_LAST; i++)
+    {
+      if (tdesc == i386_tdescs[i])
+	return i;
+    }
+
+  return 0;
+}
+
+#endif
diff --git a/gdb/gdbserver/linux-x86-tdesc.h b/gdb/gdbserver/linux-x86-tdesc.h
index bbe4078..894cf4e 100644
--- a/gdb/gdbserver/linux-x86-tdesc.h
+++ b/gdb/gdbserver/linux-x86-tdesc.h
@@ -30,6 +30,7 @@ enum x86_linux_tdesc {
   X86_TDESC_AVX_MPX = 4,
   X86_TDESC_AVX_AVX512 = 5,
   X86_TDESC_AVX_MPX_AVX512_PKU = 6,
+  X86_TDESC_LAST = 7,
 };
 
 #ifdef __x86_64__
@@ -77,31 +78,9 @@ extern const struct target_desc *tdesc_x32_avx_avx512_linux;
 #endif
 
 #if defined __i386__ || !defined IN_PROCESS_AGENT
-/* Defined in auto-generated file i386-linux.c.  */
-void init_registers_i386_linux (void);
-extern const struct target_desc *tdesc_i386_linux;
-
-/* Defined in auto-generated file i386-mmx-linux.c.  */
-void init_registers_i386_mmx_linux (void);
-extern const struct target_desc *tdesc_i386_mmx_linux;
-
-/* Defined in auto-generated file i386-avx-linux.c.  */
-void init_registers_i386_avx_linux (void);
-extern const struct target_desc *tdesc_i386_avx_linux;
-
-/* Defined in auto-generated file i386-avx-mpx-linux.c.  */
-void init_registers_i386_avx_mpx_linux (void);
-extern const struct target_desc *tdesc_i386_avx_mpx_linux;
-
-/* Defined in auto-generated file i386-avx-avx512-linux.c.  */
-void init_registers_i386_avx_avx512_linux (void);
-extern const struct target_desc *tdesc_i386_avx_avx512_linux;
+int i386_get_ipa_tdesc_idx (const struct target_desc *tdesc);
+#endif
 
-/* Defined in auto-generated file i386-avx-mpx-avx512-linux.c.  */
-void init_registers_i386_avx_mpx_avx512_pku_linux (void);
-extern const struct target_desc *tdesc_i386_avx_mpx_avx512_pku_linux;
+const struct target_desc *i386_get_ipa_tdesc (int idx);
 
-/* Defined in auto-generated file i386-mpx-linux.c.  */
-void init_registers_i386_mpx_linux (void);
-extern const struct target_desc *tdesc_i386_mpx_linux;
-#endif
+void initialize_low_tdesc ();