[patch v4 07/13] xml, btrace: define btrace xml document style

[markus.t.metzger@intel.com]

From: Markus Metzger <markus.t.metzger@intel.com>

Define the xml document style for transferring branch trace data.

Add a function to parse a btrace xml document into a vector of branch trace
blocks.

2012-11-27 Markus Metzger <markus.t.metzger@intel.com>

	* features/btrace.dtd: New file.
	* Makefile.in (XMLFILES): Add btrace.dtd.
	* btrace.h (parse_xml_btrace): New declaration.
	* btrace.c (parse_xml_btrace): New function.
	(parse_xml_btrace_block): New function.
	(block_attributes): New struct.
	(btrace_attributes): New struct.
	(btrace_children): New struct.
	(btrace_elements): New struct.


---
 gdb/Makefile.in         |    3 +-
 gdb/btrace.c            |   89 +++++++++++++++++++++++++++++++++++++++++++++++
 gdb/btrace.h            |    3 ++
 gdb/features/btrace.dtd |   12 ++++++
 4 files changed, 106 insertions(+), 1 deletions(-)
 create mode 100644 gdb/features/btrace.dtd

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 584de8a..d2e3d4c 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -494,7 +494,8 @@ RUNTESTFLAGS=
 XMLFILES = $(srcdir)/features/gdb-target.dtd $(srcdir)/features/xinclude.dtd \
 	$(srcdir)/features/library-list.dtd \
 	$(srcdir)/features/library-list-svr4.dtd $(srcdir)/features/osdata.dtd \
-	$(srcdir)/features/threads.dtd $(srcdir)/features/traceframe-info.dtd
+	$(srcdir)/features/threads.dtd $(srcdir)/features/traceframe-info.dtd \
+	$(srcdir)/features/btrace.dtd
 
 # This is ser-unix.o for any system which supports a v7/BSD/SYSV/POSIX
 # interface to the serial port.  Hopefully if get ported to OS/2, VMS,
diff --git a/gdb/btrace.c b/gdb/btrace.c
index aaadc41..187287b 100644
--- a/gdb/btrace.c
+++ b/gdb/btrace.c
@@ -32,6 +32,7 @@
 #include "arch-utils.h"
 #include "disasm.h"
 #include "gdbarch.h"
+#include "xml-support.h"
 
 #include <ctype.h>
 #include <string.h>
@@ -716,6 +717,94 @@ cmd_btrace (char *args, int from_tty)
     do_btrace_range (tp, flags, args);
 }
 
+#if defined(HAVE_LIBEXPAT)
+
+/* Check the btrace document version.  */
+static void
+check_xml_btrace_version (struct gdb_xml_parser *parser,
+			  const struct gdb_xml_element *element,
+			  void *user_data, VEC (gdb_xml_value_s) *attributes)
+{
+  const char *version = xml_find_attribute (attributes, "version")->value;
+
+  if (strcmp (version, "1.0") != 0)
+    gdb_xml_error (parser, _("Unsupported btrace version: \"%s\""), version);
+}
+
+/* Parse a btrace "block" xml record.  */
+static void
+parse_xml_btrace_block (struct gdb_xml_parser *parser,
+			const struct gdb_xml_element *element,
+			void *user_data, VEC (gdb_xml_value_s) *attributes)
+{
+  VEC (btrace_block_s) **btrace = user_data;
+  struct btrace_block *block = VEC_safe_push (btrace_block_s, *btrace, NULL);
+  ULONGEST *begin, *end;
+
+  begin = xml_find_attribute (attributes, "begin")->value;
+  end = xml_find_attribute (attributes, "end")->value;
+
+  block->begin = *begin;
+  block->end = *end;
+}
+
+static const struct gdb_xml_attribute block_attributes[] = {
+  { "begin", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
+  { "end", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
+  { NULL, GDB_XML_AF_NONE, NULL, NULL }
+};
+
+static const struct gdb_xml_attribute btrace_attributes[] = {
+  { "version", GDB_XML_AF_NONE, NULL, NULL },
+  { NULL, GDB_XML_AF_NONE, NULL, NULL }
+};
+
+static const struct gdb_xml_element btrace_children[] = {
+  { "block", block_attributes, NULL,
+    GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL, parse_xml_btrace_block, NULL },
+  { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
+};
+
+static const struct gdb_xml_element btrace_elements[] = {
+  { "btrace", btrace_attributes, btrace_children, GDB_XML_EF_NONE,
+    check_xml_btrace_version, NULL },
+  { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
+};
+
+#endif /* defined(HAVE_LIBEXPAT) */
+
+/* See btrace.h.  */
+VEC (btrace_block_s) *
+parse_xml_btrace (const char *buffer)
+{
+  VEC (btrace_block_s) *btrace = NULL;
+  struct cleanup *cleanup;
+  int errcode;
+
+#if defined(HAVE_LIBEXPAT)
+
+  cleanup = make_cleanup (VEC_cleanup (btrace_block_s), &btrace);
+  errcode = gdb_xml_parse_quick (_("btrace"), "btrace.dtd", btrace_elements,
+				 buffer, &btrace);
+  if (errcode)
+    {
+      do_cleanups (cleanup);
+      errno = errcode;
+      return NULL;
+    }
+
+  /* Keep parse results.  */
+  discard_cleanups (cleanup);
+
+#else  /* !defined(HAVE_LIBEXPAT) */
+
+  error (_("Cannot process branch tracing result. XML parsing not supported."));
+
+#endif  /* !defined(HAVE_LIBEXPAT) */
+
+  return btrace;
+}
+
 void _initialize_btrace (void);
 
 /* Initialize btrace commands.  */
diff --git a/gdb/btrace.h b/gdb/btrace.h
index e70a46e..855162f 100644
--- a/gdb/btrace.h
+++ b/gdb/btrace.h
@@ -71,4 +71,7 @@ extern struct btrace_block *read_btrace (struct thread_info *, int);
 extern struct btrace_block *prev_btrace (struct thread_info *);
 extern struct btrace_block *next_btrace (struct thread_info *);
 
+/* Parse a branch trace xml document into a block vector.  */
+extern VEC (btrace_block_s) *parse_xml_btrace (const char*);
+
 #endif /* BTRACE_H */
diff --git a/gdb/features/btrace.dtd b/gdb/features/btrace.dtd
new file mode 100644
index 0000000..7e6bfd0
--- /dev/null
+++ b/gdb/features/btrace.dtd
@@ -0,0 +1,12 @@
+<!-- Copyright (C) 2012 Free Software Foundation, Inc.
+
+     Copying and distribution of this file, with or without modification,
+     are permitted in any medium without royalty provided the copyright
+     notice and this notice are preserved.  -->
+
+<!ELEMENT btrace  (block)* >
+<!ATTLIST btrace  version CDATA   #REQUIRED>
+
+<!ELEMENT block        EMPTY>
+<!ATTLIST block        begin  CDATA   #REQUIRED
+                       end    CDATA   #REQUIRED>
-- 
1.7.1