Dynamically composite xml in reply to GDB

GDBserver still uses pre-generated target descriptions in order to
reply to GDB's query on target description (see xml-builtin-generated.c
in GDBserver build directory).  This patch teaches GDBserver to
create XML contents according to the target descriptions rather than
using pre-generated ones.

First, change target feature c files to pass the feature xml file
name to tdesc_create_feature, so that target description in GDBserver
can record them, and create XML contents from these features in
buffer, like

  ...
  <xi:include href="$FEATURE1_XML_NAME"/>
  <xi:include href="$FEATURE2_XML_NAME"/>
  ...

and send this buffer back to GDB.

Note that this patch reuses target_desc.xmltarget a little bit, which is
to hold the XML contents dynamically generated in tdesc_get_features_xml.
However, it is not xfree'ed in ~target_desc, because we can't tell it is
from xstrdup or a literal string.  Since we don't delete target_desc,
there is no memory leak yet.  After we change all target descriptions to
the new style, target_desc.xmltarget is from xstrdup, then, we can safely
xfree it in ~target_desc.

gdb:

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

	* arch/tdesc.h (tdesc_create_feature): Add an argument xml.
	* target-descriptions.c (tdesc_create_feature): Likewise, and
	adjust code.
	* 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.

gdb/gdbserver:

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

	* linux-x86-tdesc.c: Don't include <inttypes.h>.
	(i386_linux_read_description) [!IN_PROCESS_AGENT]: Call
	set_tdesc_architecture and set_tdesc_osabi.  Remove code setting
	.xmltarget.
	* server.c (get_features_xml): Call tdesc_get_features_xml.
	* tdesc.c (set_tdesc_architecture): New function.
	(set_tdesc_osabi): New function.
	(tdesc_get_features_xml): New function.
	(tdesc_create_feature): Add an argument.
	* tdesc.h (struct target_desc) <features>: New field.
	<arch, osabi>: New field.
	(~target_desc): xfree features, arch, and osabi.
	(target_desc::oerator==): Don't compare .xmltarget.
	[!IN_PROCESS_AGENT] (set_tdesc_architecture): Declare.
	(set_tdesc_osabi): Likewise.
	(tdesc_get_features_xml): Likewise.

1 files changed, 6 insertions, 3 deletions

diff --git a/gdb/target-descriptions.c b/gdb/target-descriptions.c
index f0ced66..6135e0d 100644
--- a/gdb/target-descriptions.c
+++ b/gdb/target-descriptions.c
@@ -1750,7 +1750,8 @@ tdesc_add_enum_value (struct tdesc_type *type, int value,
 /* See arch/tdesc.h.  */
 
 struct tdesc_feature *
-tdesc_create_feature (struct target_desc *tdesc, const char *name)
+tdesc_create_feature (struct target_desc *tdesc, const char *name,
+		      const char *xml)
 {
   struct tdesc_feature *new_feature = new tdesc_feature (name);
 
@@ -2202,8 +2203,10 @@ public:
 
     printf_unfiltered ("{\n");
     printf_unfiltered ("  struct tdesc_feature *feature;\n");
-    printf_unfiltered ("\n  feature = tdesc_create_feature (result, \"%s\");\n",
-		       e->name);
+
+    printf_unfiltered
+      ("\n  feature = tdesc_create_feature (result, \"%s\", \"%s\");\n",
+       e->name, lbasename (m_filename_after_features.c_str ()));
   }
 
   void visit_post (const tdesc_feature *e) override