[GDBserver] Centralize tdesc for i386-linux

tdesc_i386_XXX_linux is used in many places in linux-x86-low.c and this
patch adds a new function i386_linux_read_description to return the right
tdesc according to xcr0.  i386_linux_read_description is quite similar to
the counterpart in GDB, and the following patch will share the duplicated
code, so this patch adds arch/tdesc.h includes the declarations of various
tdesc apis which are used by the shared code.  The generated c feature
files can include arch/tdesc.h only.

gdb/gdbserver:

2017-09-05  Yao Qi  <yao.qi@linaro.org>

	* configure.srv (srv_tgtobj): Append linux-x86-tdesc.o.
	(ipa_obj): Likewise.
	* linux-i386-ipa.c: Include common/x86-xstate.h
	(get_ipa_tdesc): Call i386_linux_read_description.
	(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_linux_read_description.
	(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.

gdb:

2017-09-05  Yao Qi  <yao.qi@linaro.org>

	* arch/tdesc.h: New file.
	* regformats/regdat.sh: Generate code using tdesc_create_reg.
	* target-descriptions.c: Update comments.
	* target-descriptions.h: Include "arch/tdesc.h".  Remove the
	declarations.
	* features/i386/32bit-avx.c: Re-generated.
	* features/i386/32bit-avx512.c: Re-generated.
	* features/i386/32bit-core.c: Re-generated.
	* features/i386/32bit-linux.c: Re-generated.
	* features/i386/32bit-mpx.c: Re-generated.
	* features/i386/32bit-pkeys.c: Re-generated.
	* features/i386/32bit-sse.c: Re-generated.

1 files changed, 25 insertions, 4 deletions

diff --git a/gdb/gdbserver/tdesc.h b/gdb/gdbserver/tdesc.h
index 424a2fd..50d0364 100644
--- a/gdb/gdbserver/tdesc.h
+++ b/gdb/gdbserver/tdesc.h
@@ -19,14 +19,20 @@
 #ifndef TDESC_H
 #define TDESC_H
 
+#include "arch/tdesc.h"
+
 struct reg;
 
 typedef struct reg *tdesc_reg_p;
 DEF_VEC_P(tdesc_reg_p);
 
-/* A target description.  */
+struct tdesc_feature
+{};
+
+/* A target description.  Inherit from tdesc_feature so that target_desc
+   can be used as tdesc_feature.  */
 
-struct target_desc
+struct target_desc : tdesc_feature
 {
   /* A vector of elements of register definitions that
      describe the inferior's register set.  */
@@ -38,13 +44,28 @@ struct target_desc
 #ifndef IN_PROCESS_AGENT
   /* An array of register names.  These are the "expedite" registers:
      registers whose values are sent along with stop replies.  */
-  const char **expedite_regs;
+  const char **expedite_regs = NULL;
 
   /* Defines what to return when looking for the "target.xml" file in
      response to qXfer:features:read.  Its contents can either be
      verbatim XML code (prefixed with a '@') or else the name of the
      actual XML file to be used in place of "target.xml".  */
-  const char *xmltarget;
+  const char *xmltarget = NULL;
+
+public:
+  target_desc ()
+    : reg_defs (NULL), registers_size (0)
+  {}
+
+  ~target_desc ()
+  {
+    int i;
+    struct reg *reg;
+
+    for (i = 0; VEC_iterate (tdesc_reg_p, reg_defs, i, reg); i++)
+      xfree (reg);
+    VEC_free (tdesc_reg_p, reg_defs);
+  }
 #endif
 };