Replace VEC(gdb_xml_value_s) with std::vector

This patch replaces VEC(gdb_xml_value_s), which is passed to XML
visitors, with an std::vector.  In order to be able to remove the
cleanup in gdb_xml_parser::start_element, the gdb_xml_parser structure
is made to own the value with a gdb::unique_xmalloc_ptr.

This patch has been tested on the buildbot.

gdb/ChangeLog:

	* xml-support.h (struct gdb_xml_value): Add constructor.
	<value>: Change type to unique_xmalloc_ptr.
	(gdb_xml_value_s): Remove typedef.
	(DEF_VEC_O (gdb_xml_value_s)): Remove.
	(gdb_xml_element_start_handler): Change parameter type to
	std::vector.
	(xml_find_attribute): Likewise.
	* xml-support.c (xml_find_attribute): Change parameter type to
	std::vector and adjust.
	(gdb_xml_values_cleanup): Remove.
	(gdb_xml_parser::start_element): Adjust to std::vector.
	(xinclude_start_include): Change paraeter type to std::vector
	and adjust.
	* btrace.c (check_xml_btrace_version): Likewise.
	(parse_xml_btrace_block): Likewise.
	(parse_xml_btrace_pt_config_cpu): Likewise.
	(parse_xml_btrace_pt): Likewise.
	(parse_xml_btrace_conf_bts): Likewise.
	(parse_xml_btrace_conf_pt): Likewise.
	* memory-map.c (memory_map_start_memory): Likewise.
	(memory_map_start_property): Likewise.
	* osdata.c (osdata_start_osdata): Likewise.
	(osdata_start_item): Likewise.
	(osdata_start_column): Likewise.
	* remote.c (start_thread): Likewise.
	* solib-aix.c (library_list_start_library): Likewise.
	(library_list_start_list): Likewise.
	* solib-svr4.c (library_list_start_library): Likewise.
	(svr4_library_list_start_list): Likewise.
	* solib-target.c (library_list_start_segment): Likewise.
	(library_list_start_section): Likewise.
	(library_list_start_library): Likewise.
	(library_list_start_list): Likewise.
	* tracepoint.c (traceframe_info_start_memory): Likewise.
	(traceframe_info_start_tvar): Likewise.
	* xml-syscall.c (syscall_start_syscall): Likewise.
	* xml-tdesc.c (tdesc_start_target): Likewise.
	(tdesc_start_feature): Likewise.
	(tdesc_start_reg): Likewise.
	(tdesc_start_union): Likewise.
	(tdesc_start_struct): Likewise.
	(tdesc_start_flags): Likewise.
	(tdesc_start_enum): Likewise.
	(tdesc_start_field): Likewise.
	(tdesc_start_enum_value): Likewise.
	(tdesc_start_vector): Likewise.

13 files changed, 203 insertions, 154 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index ff45306..585ad5e 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,54 @@
 2018-01-07  Simon Marchi  <simon.marchi@polymtl.ca>
 
+	* xml-support.h (struct gdb_xml_value): Add constructor.
+	<value>: Change type to unique_xmalloc_ptr.
+	(gdb_xml_value_s): Remove typedef.
+	(DEF_VEC_O (gdb_xml_value_s)): Remove.
+	(gdb_xml_element_start_handler): Change parameter type to
+	std::vector.
+	(xml_find_attribute): Likewise.
+	* xml-support.c (xml_find_attribute): Change parameter type to
+	std::vector and adjust.
+	(gdb_xml_values_cleanup): Remove.
+	(gdb_xml_parser::start_element): Adjust to std::vector.
+	(xinclude_start_include): Change paraeter type to std::vector
+	and adjust.
+	* btrace.c (check_xml_btrace_version): Likewise.
+	(parse_xml_btrace_block): Likewise.
+	(parse_xml_btrace_pt_config_cpu): Likewise.
+	(parse_xml_btrace_pt): Likewise.
+	(parse_xml_btrace_conf_bts): Likewise.
+	(parse_xml_btrace_conf_pt): Likewise.
+	* memory-map.c (memory_map_start_memory): Likewise.
+	(memory_map_start_property): Likewise.
+	* osdata.c (osdata_start_osdata): Likewise.
+	(osdata_start_item): Likewise.
+	(osdata_start_column): Likewise.
+	* remote.c (start_thread): Likewise.
+	* solib-aix.c (library_list_start_library): Likewise.
+	(library_list_start_list): Likewise.
+	* solib-svr4.c (library_list_start_library): Likewise.
+	(svr4_library_list_start_list): Likewise.
+	* solib-target.c (library_list_start_segment): Likewise.
+	(library_list_start_section): Likewise.
+	(library_list_start_library): Likewise.
+	(library_list_start_list): Likewise.
+	* tracepoint.c (traceframe_info_start_memory): Likewise.
+	(traceframe_info_start_tvar): Likewise.
+	* xml-syscall.c (syscall_start_syscall): Likewise.
+	* xml-tdesc.c (tdesc_start_target): Likewise.
+	(tdesc_start_feature): Likewise.
+	(tdesc_start_reg): Likewise.
+	(tdesc_start_union): Likewise.
+	(tdesc_start_struct): Likewise.
+	(tdesc_start_flags): Likewise.
+	(tdesc_start_enum): Likewise.
+	(tdesc_start_field): Likewise.
+	(tdesc_start_enum_value): Likewise.
+	(tdesc_start_vector): Likewise.
+
+2018-01-07  Simon Marchi  <simon.marchi@polymtl.ca>
+
 	* extension.h (struct xmethod_worker) <clone>: Remove.
 	* python/py-xmethods.c (struct python_xmethod_worker) <clone>:
 	Remove.
diff --git a/gdb/btrace.c b/gdb/btrace.c
index 8823046..ffcf53a 100644
--- a/gdb/btrace.c
+++ b/gdb/btrace.c
@@ -2002,10 +2002,11 @@ btrace_free_objfile (struct objfile *objfile)
 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)
+			  void *user_data,
+			  std::vector<gdb_xml_value> &attributes)
 {
   const char *version
-    = (const char *) xml_find_attribute (attributes, "version")->value;
+    = (const char *) xml_find_attribute (attributes, "version")->value.get ();
 
   if (strcmp (version, "1.0") != 0)
     gdb_xml_error (parser, _("Unsupported btrace version: \"%s\""), version);
@@ -2016,7 +2017,8 @@ check_xml_btrace_version (struct gdb_xml_parser *parser,
 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)
+			void *user_data,
+			std::vector<gdb_xml_value> &attributes)
 {
   struct btrace_data *btrace;
   struct btrace_block *block;
@@ -2038,8 +2040,8 @@ parse_xml_btrace_block (struct gdb_xml_parser *parser,
       gdb_xml_error (parser, _("Btrace format error."));
     }
 
-  begin = (ULONGEST *) xml_find_attribute (attributes, "begin")->value;
-  end = (ULONGEST *) xml_find_attribute (attributes, "end")->value;
+  begin = (ULONGEST *) xml_find_attribute (attributes, "begin")->value.get ();
+  end = (ULONGEST *) xml_find_attribute (attributes, "end")->value.get ();
 
   block = VEC_safe_push (btrace_block_s, btrace->variant.bts.blocks, NULL);
   block->begin = *begin;
@@ -2092,16 +2094,20 @@ static void
 parse_xml_btrace_pt_config_cpu (struct gdb_xml_parser *parser,
 				const struct gdb_xml_element *element,
 				void *user_data,
-				VEC (gdb_xml_value_s) *attributes)
+				std::vector<gdb_xml_value> &attributes)
 {
   struct btrace_data *btrace;
   const char *vendor;
   ULONGEST *family, *model, *stepping;
 
-  vendor = (const char *) xml_find_attribute (attributes, "vendor")->value;
-  family = (ULONGEST *) xml_find_attribute (attributes, "family")->value;
-  model = (ULONGEST *) xml_find_attribute (attributes, "model")->value;
-  stepping = (ULONGEST *) xml_find_attribute (attributes, "stepping")->value;
+  vendor =
+    (const char *) xml_find_attribute (attributes, "vendor")->value.get ();
+  family
+    = (ULONGEST *) xml_find_attribute (attributes, "family")->value.get ();
+  model
+    = (ULONGEST *) xml_find_attribute (attributes, "model")->value.get ();
+  stepping
+    = (ULONGEST *) xml_find_attribute (attributes, "stepping")->value.get ();
 
   btrace = (struct btrace_data *) user_data;
 
@@ -2132,7 +2138,8 @@ parse_xml_btrace_pt_raw (struct gdb_xml_parser *parser,
 static void
 parse_xml_btrace_pt (struct gdb_xml_parser *parser,
 		     const struct gdb_xml_element *element,
-		     void *user_data, VEC (gdb_xml_value_s) *attributes)
+		     void *user_data,
+		     std::vector<gdb_xml_value> &attributes)
 {
   struct btrace_data *btrace;
 
@@ -2226,7 +2233,8 @@ parse_xml_btrace (struct btrace_data *btrace, const char *buffer)
 static void
 parse_xml_btrace_conf_bts (struct gdb_xml_parser *parser,
 			  const struct gdb_xml_element *element,
-			  void *user_data, VEC (gdb_xml_value_s) *attributes)
+			  void *user_data,
+			  std::vector<gdb_xml_value> &attributes)
 {
   struct btrace_config *conf;
   struct gdb_xml_value *size;
@@ -2237,7 +2245,7 @@ parse_xml_btrace_conf_bts (struct gdb_xml_parser *parser,
 
   size = xml_find_attribute (attributes, "size");
   if (size != NULL)
-    conf->bts.size = (unsigned int) *(ULONGEST *) size->value;
+    conf->bts.size = (unsigned int) *(ULONGEST *) size->value.get ();
 }
 
 /* Parse a btrace-conf "pt" xml record.  */
@@ -2245,7 +2253,8 @@ parse_xml_btrace_conf_bts (struct gdb_xml_parser *parser,
 static void
 parse_xml_btrace_conf_pt (struct gdb_xml_parser *parser,
 			  const struct gdb_xml_element *element,
-			  void *user_data, VEC (gdb_xml_value_s) *attributes)
+			  void *user_data,
+			  std::vector<gdb_xml_value> &attributes)
 {
   struct btrace_config *conf;
   struct gdb_xml_value *size;
@@ -2256,7 +2265,7 @@ parse_xml_btrace_conf_pt (struct gdb_xml_parser *parser,
 
   size = xml_find_attribute (attributes, "size");
   if (size != NULL)
-    conf->pt.size = (unsigned int) *(ULONGEST *) size->value;
+    conf->pt.size = (unsigned int) *(ULONGEST *) size->value.get ();
 }
 
 static const struct gdb_xml_attribute btrace_conf_pt_attributes[] = {
diff --git a/gdb/memory-map.c b/gdb/memory-map.c
index 55b207e..6a1220e 100644
--- a/gdb/memory-map.c
+++ b/gdb/memory-map.c
@@ -58,18 +58,19 @@ struct memory_map_parsing_data
 static void
 memory_map_start_memory (struct gdb_xml_parser *parser,
 			 const struct gdb_xml_element *element,
-			 void *user_data, VEC(gdb_xml_value_s) *attributes)
+			 void *user_data,
+			 std::vector<gdb_xml_value> &attributes)
 {
   struct memory_map_parsing_data *data
     = (struct memory_map_parsing_data *) user_data;
   ULONGEST *start_p, *length_p, *type_p;
 
   start_p
-    = (ULONGEST *) xml_find_attribute (attributes, "start")->value;
+    = (ULONGEST *) xml_find_attribute (attributes, "start")->value.get ();
   length_p
-    = (ULONGEST *) xml_find_attribute (attributes, "length")->value;
+    = (ULONGEST *) xml_find_attribute (attributes, "length")->value.get ();
   type_p
-    = (ULONGEST *) xml_find_attribute (attributes, "type")->value;
+    = (ULONGEST *) xml_find_attribute (attributes, "type")->value.get ();
 
   data->memory_map->emplace_back (*start_p, *start_p + *length_p,
 				  (enum mem_access_mode) *type_p);
@@ -97,13 +98,14 @@ memory_map_end_memory (struct gdb_xml_parser *parser,
 static void
 memory_map_start_property (struct gdb_xml_parser *parser,
 			   const struct gdb_xml_element *element,
-			   void *user_data, VEC(gdb_xml_value_s) *attributes)
+			   void *user_data,
+			   std::vector<gdb_xml_value> &attributes)
 {
   struct memory_map_parsing_data *data
     = (struct memory_map_parsing_data *) user_data;
   char *name;
 
-  name = (char *) xml_find_attribute (attributes, "name")->value;
+  name = (char *) xml_find_attribute (attributes, "name")->value.get ();
   data->property_name.assign (name);
 }
 
diff --git a/gdb/osdata.c b/gdb/osdata.c
index f390940..5c41cb1 100644
--- a/gdb/osdata.c
+++ b/gdb/osdata.c
@@ -56,14 +56,15 @@ struct osdata_parsing_data
 static void
 osdata_start_osdata (struct gdb_xml_parser *parser,
                         const struct gdb_xml_element *element,
-                        void *user_data, VEC(gdb_xml_value_s) *attributes)
+                        void *user_data,
+			std::vector<gdb_xml_value> &attributes)
 {
   struct osdata_parsing_data *data = (struct osdata_parsing_data *) user_data;
 
   if (data->osdata != NULL)
     gdb_xml_error (parser, _("Seen more than on osdata element"));
 
-  char *type = (char *) xml_find_attribute (attributes, "type")->value;
+  char *type = (char *) xml_find_attribute (attributes, "type")->value.get ();
   data->osdata.reset (new struct osdata (std::string (type)));
 }
 
@@ -72,7 +73,8 @@ osdata_start_osdata (struct gdb_xml_parser *parser,
 static void
 osdata_start_item (struct gdb_xml_parser *parser,
                   const struct gdb_xml_element *element,
-                  void *user_data, VEC(gdb_xml_value_s) *attributes)
+                  void *user_data,
+		  std::vector<gdb_xml_value> &attributes)
 {
   struct osdata_parsing_data *data = (struct osdata_parsing_data *) user_data;
   data->osdata->items.emplace_back ();
@@ -83,11 +85,12 @@ osdata_start_item (struct gdb_xml_parser *parser,
 static void
 osdata_start_column (struct gdb_xml_parser *parser,
                     const struct gdb_xml_element *element,
-                    void *user_data, VEC(gdb_xml_value_s) *attributes)
+                    void *user_data,
+		    std::vector<gdb_xml_value> &attributes)
 {
   struct osdata_parsing_data *data = (struct osdata_parsing_data *) user_data;
   const char *name
-    = (const char *) xml_find_attribute (attributes, "name")->value;
+    = (const char *) xml_find_attribute (attributes, "name")->value.get ();
 
   data->property_name.assign (name);
 }
diff --git a/gdb/remote.c b/gdb/remote.c
index 9ff6028..81c772a 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -3077,13 +3077,14 @@ remote_get_threads_with_ql (struct target_ops *ops,
 static void
 start_thread (struct gdb_xml_parser *parser,
 	      const struct gdb_xml_element *element,
-	      void *user_data, VEC(gdb_xml_value_s) *attributes)
+	      void *user_data,
+	      std::vector<gdb_xml_value> &attributes)
 {
   struct threads_listing_context *data
     = (struct threads_listing_context *) user_data;
   struct gdb_xml_value *attr;
 
-  char *id = (char *) xml_find_attribute (attributes, "id")->value;
+  char *id = (char *) xml_find_attribute (attributes, "id")->value.get ();
   ptid_t ptid = read_ptid (id, NULL);
 
   data->items.emplace_back (ptid);
@@ -3091,15 +3092,15 @@ start_thread (struct gdb_xml_parser *parser,
 
   attr = xml_find_attribute (attributes, "core");
   if (attr != NULL)
-    item.core = *(ULONGEST *) attr->value;
+    item.core = *(ULONGEST *) attr->value.get ();
 
   attr = xml_find_attribute (attributes, "name");
   if (attr != NULL)
-    item.name = (const char *) attr->value;
+    item.name = (const char *) attr->value.get ();
 
   attr = xml_find_attribute (attributes, "handle");
   if (attr != NULL)
-    item.thread_handle = hex2bin ((const char *) attr->value);
+    item.thread_handle = hex2bin ((const char *) attr->value.get ());
 }
 
 static void
diff --git a/gdb/solib-aix.c b/gdb/solib-aix.c
index 74f0eaa..463f060 100644
--- a/gdb/solib-aix.c
+++ b/gdb/solib-aix.c
@@ -134,30 +134,30 @@ static void
 library_list_start_library (struct gdb_xml_parser *parser,
 			    const struct gdb_xml_element *element,
 			    void *user_data,
-			    VEC (gdb_xml_value_s) *attributes)
+			    std::vector<gdb_xml_value> &attributes)
 {
   VEC (lm_info_aix_p) **list = (VEC (lm_info_aix_p) **) user_data;
   lm_info_aix *item = new lm_info_aix;
   struct gdb_xml_value *attr;
 
   attr = xml_find_attribute (attributes, "name");
-  item->filename = xstrdup ((const char *) attr->value);
+  item->filename = xstrdup ((const char *) attr->value.get ());
 
   attr = xml_find_attribute (attributes, "member");
   if (attr != NULL)
-    item->member_name = xstrdup ((const char *) attr->value);
+    item->member_name = xstrdup ((const char *) attr->value.get ());
 
   attr = xml_find_attribute (attributes, "text_addr");
-  item->text_addr = * (ULONGEST *) attr->value;
+  item->text_addr = * (ULONGEST *) attr->value.get ();
 
   attr = xml_find_attribute (attributes, "text_size");
-  item->text_size = * (ULONGEST *) attr->value;
+  item->text_size = * (ULONGEST *) attr->value.get ();
 
   attr = xml_find_attribute (attributes, "data_addr");
-  item->data_addr = * (ULONGEST *) attr->value;
+  item->data_addr = * (ULONGEST *) attr->value.get ();
 
   attr = xml_find_attribute (attributes, "data_size");
-  item->data_size = * (ULONGEST *) attr->value;
+  item->data_size = * (ULONGEST *) attr->value.get ();
 
   VEC_safe_push (lm_info_aix_p, *list, item);
 }
@@ -167,9 +167,11 @@ library_list_start_library (struct gdb_xml_parser *parser,
 static void
 library_list_start_list (struct gdb_xml_parser *parser,
                          const struct gdb_xml_element *element,
-                         void *user_data, VEC (gdb_xml_value_s) *attributes)
+                         void *user_data,
+			 std::vector<gdb_xml_value> &attributes)
 {
-  char *version = (char *) xml_find_attribute (attributes, "version")->value;
+  char *version
+    = (char *) xml_find_attribute (attributes, "version")->value.get ();
 
   if (strcmp (version, "1.0") != 0)
     gdb_xml_error (parser,
diff --git a/gdb/solib-svr4.c b/gdb/solib-svr4.c
index 4973cc2..c8f5e93 100644
--- a/gdb/solib-svr4.c
+++ b/gdb/solib-svr4.c
@@ -1144,17 +1144,18 @@ svr4_copy_library_list (struct so_list *src)
 static void
 library_list_start_library (struct gdb_xml_parser *parser,
 			    const struct gdb_xml_element *element,
-			    void *user_data, VEC(gdb_xml_value_s) *attributes)
+			    void *user_data,
+			    std::vector<gdb_xml_value> &attributes)
 {
   struct svr4_library_list *list = (struct svr4_library_list *) user_data;
   const char *name
-    = (const char *) xml_find_attribute (attributes, "name")->value;
+    = (const char *) xml_find_attribute (attributes, "name")->value.get ();
   ULONGEST *lmp
-    = (ULONGEST *) xml_find_attribute (attributes, "lm")->value;
+    = (ULONGEST *) xml_find_attribute (attributes, "lm")->value.get ();
   ULONGEST *l_addrp
-    = (ULONGEST *) xml_find_attribute (attributes, "l_addr")->value;
+    = (ULONGEST *) xml_find_attribute (attributes, "l_addr")->value.get ();
   ULONGEST *l_ldp
-    = (ULONGEST *) xml_find_attribute (attributes, "l_ld")->value;
+    = (ULONGEST *) xml_find_attribute (attributes, "l_ld")->value.get ();
   struct so_list *new_elem;
 
   new_elem = XCNEW (struct so_list);
@@ -1177,11 +1178,12 @@ library_list_start_library (struct gdb_xml_parser *parser,
 static void
 svr4_library_list_start_list (struct gdb_xml_parser *parser,
 			      const struct gdb_xml_element *element,
-			      void *user_data, VEC(gdb_xml_value_s) *attributes)
+			      void *user_data,
+			      std::vector<gdb_xml_value> &attributes)
 {
   struct svr4_library_list *list = (struct svr4_library_list *) user_data;
   const char *version
-    = (const char *) xml_find_attribute (attributes, "version")->value;
+    = (const char *) xml_find_attribute (attributes, "version")->value.get ();
   struct gdb_xml_value *main_lm = xml_find_attribute (attributes, "main-lm");
 
   if (strcmp (version, "1.0") != 0)
@@ -1190,7 +1192,7 @@ svr4_library_list_start_list (struct gdb_xml_parser *parser,
 		   version);
 
   if (main_lm)
-    list->main_lm = *(ULONGEST *) main_lm->value;
+    list->main_lm = *(ULONGEST *) main_lm->value.get ();
 }
 
 /* The allowed elements and attributes for an XML library list.
diff --git a/gdb/solib-target.c b/gdb/solib-target.c
index 70f864e..0968e49 100644
--- a/gdb/solib-target.c
+++ b/gdb/solib-target.c
@@ -79,12 +79,13 @@ solib_target_parse_libraries (const char *library)
 static void
 library_list_start_segment (struct gdb_xml_parser *parser,
 			    const struct gdb_xml_element *element,
-			    void *user_data, VEC(gdb_xml_value_s) *attributes)
+			    void *user_data,
+			    std::vector<gdb_xml_value> &attributes)
 {
   VEC(lm_info_target_p) **list = (VEC(lm_info_target_p) **) user_data;
   lm_info_target *last = VEC_last (lm_info_target_p, *list);
   ULONGEST *address_p
-    = (ULONGEST *) xml_find_attribute (attributes, "address")->value;
+    = (ULONGEST *) xml_find_attribute (attributes, "address")->value.get ();
   CORE_ADDR address = (CORE_ADDR) *address_p;
 
   if (!last->section_bases.empty ())
@@ -97,12 +98,13 @@ library_list_start_segment (struct gdb_xml_parser *parser,
 static void
 library_list_start_section (struct gdb_xml_parser *parser,
 			    const struct gdb_xml_element *element,
-			    void *user_data, VEC(gdb_xml_value_s) *attributes)
+			    void *user_data,
+			    std::vector<gdb_xml_value> &attributes)
 {
   VEC(lm_info_target_p) **list = (VEC(lm_info_target_p) **) user_data;
   lm_info_target *last = VEC_last (lm_info_target_p, *list);
   ULONGEST *address_p
-    = (ULONGEST *) xml_find_attribute (attributes, "address")->value;
+    = (ULONGEST *) xml_find_attribute (attributes, "address")->value.get ();
   CORE_ADDR address = (CORE_ADDR) *address_p;
 
   if (!last->segment_bases.empty ())
@@ -117,12 +119,13 @@ library_list_start_section (struct gdb_xml_parser *parser,
 static void
 library_list_start_library (struct gdb_xml_parser *parser,
 			    const struct gdb_xml_element *element,
-			    void *user_data, VEC(gdb_xml_value_s) *attributes)
+			    void *user_data,
+			    std::vector<gdb_xml_value> &attributes)
 {
   VEC(lm_info_target_p) **list = (VEC(lm_info_target_p) **) user_data;
   lm_info_target *item = new lm_info_target;
   const char *name
-    = (const char *) xml_find_attribute (attributes, "name")->value;
+    = (const char *) xml_find_attribute (attributes, "name")->value.get ();
 
   item->name = xstrdup (name);
   VEC_safe_push (lm_info_target_p, *list, item);
@@ -146,14 +149,15 @@ library_list_end_library (struct gdb_xml_parser *parser,
 static void
 library_list_start_list (struct gdb_xml_parser *parser,
 			 const struct gdb_xml_element *element,
-			 void *user_data, VEC(gdb_xml_value_s) *attributes)
+			 void *user_data,
+			 std::vector<gdb_xml_value> &attributes)
 {
   struct gdb_xml_value *version = xml_find_attribute (attributes, "version");
 
   /* #FIXED attribute may be omitted, Expat returns NULL in such case.  */
   if (version != NULL)
     {
-      const char *string = (const char *) version->value;
+      const char *string = (const char *) version->value.get ();
 
       if (strcmp (string, "1.0") != 0)
 	gdb_xml_error (parser,
diff --git a/gdb/tracepoint.c b/gdb/tracepoint.c
index b0f855a..f34f103 100644
--- a/gdb/tracepoint.c
+++ b/gdb/tracepoint.c
@@ -3959,15 +3959,16 @@ parse_traceframe_info (const char *tframe_info)
 static void
 traceframe_info_start_memory (struct gdb_xml_parser *parser,
 			      const struct gdb_xml_element *element,
-			      void *user_data, VEC(gdb_xml_value_s) *attributes)
+			      void *user_data,
+			      std::vector<gdb_xml_value> &attributes)
 {
   struct traceframe_info *info = (struct traceframe_info *) user_data;
   ULONGEST *start_p, *length_p;
 
   start_p
-    = (ULONGEST *) xml_find_attribute (attributes, "start")->value;
+    = (ULONGEST *) xml_find_attribute (attributes, "start")->value.get ();
   length_p
-    = (ULONGEST *) xml_find_attribute (attributes, "length")->value;
+    = (ULONGEST *) xml_find_attribute (attributes, "length")->value.get ();
 
   info->memory.emplace_back (*start_p, *length_p);
 }
@@ -3978,11 +3979,11 @@ static void
 traceframe_info_start_tvar (struct gdb_xml_parser *parser,
 			     const struct gdb_xml_element *element,
 			     void *user_data,
-			     VEC(gdb_xml_value_s) *attributes)
+			     std::vector<gdb_xml_value> &attributes)
 {
   struct traceframe_info *info = (struct traceframe_info *) user_data;
   const char *id_attrib
-    = (const char *) xml_find_attribute (attributes, "id")->value;
+    = (const char *) xml_find_attribute (attributes, "id")->value.get ();
   int id = gdb_xml_parse_ulongest (parser, id_attrib);
 
   info->tvars.push_back (id);
diff --git a/gdb/xml-support.c b/gdb/xml-support.c
index dacc5c4..2547882 100644
--- a/gdb/xml-support.c
+++ b/gdb/xml-support.c
@@ -228,32 +228,16 @@ gdb_xml_error (struct gdb_xml_parser *parser, const char *format, ...)
    ATTRIBUTES.  Returns NULL if not found.  */
 
 struct gdb_xml_value *
-xml_find_attribute (VEC(gdb_xml_value_s) *attributes, const char *name)
+xml_find_attribute (std::vector<gdb_xml_value> &attributes,
+		    const char *name)
 {
-  struct gdb_xml_value *value;
-  int ix;
-
-  for (ix = 0; VEC_iterate (gdb_xml_value_s, attributes, ix, value); ix++)
-    if (strcmp (value->name, name) == 0)
-      return value;
+  for (gdb_xml_value &value : attributes)
+    if (strcmp (value.name, name) == 0)
+      return &value;
 
   return NULL;
 }
 
-/* Clean up a vector of parsed attribute values.  */
-
-static void
-gdb_xml_values_cleanup (void *data)
-{
-  VEC(gdb_xml_value_s) **values = (VEC(gdb_xml_value_s) **) data;
-  struct gdb_xml_value *value;
-  int ix;
-
-  for (ix = 0; VEC_iterate (gdb_xml_value_s, *values, ix, value); ix++)
-    xfree (value->value);
-  VEC_free (gdb_xml_value_s, *values);
-}
-
 /* Handle the start of an element.  NAME is the element, and ATTRS are
    the names and values of this element's attributes.  */
 
@@ -266,9 +250,7 @@ gdb_xml_parser::start_element (const XML_Char *name,
 
   const struct gdb_xml_element *element;
   const struct gdb_xml_attribute *attribute;
-  VEC(gdb_xml_value_s) *attributes = NULL;
   unsigned int seen;
-  struct cleanup *back_to;
 
   /* Push an error scope.  If we return or throw an exception before
      filling this in, it will tell us to ignore children of this
@@ -317,7 +299,7 @@ gdb_xml_parser::start_element (const XML_Char *name,
 
   scope.seen |= seen;
 
-  back_to = make_cleanup (gdb_xml_values_cleanup, &attributes);
+  std::vector<gdb_xml_value> attributes;
 
   for (attribute = element->attributes;
        attribute != NULL && attribute->name != NULL;
@@ -326,7 +308,6 @@ gdb_xml_parser::start_element (const XML_Char *name,
       const char *val = NULL;
       const XML_Char **p;
       void *parsed_value;
-      struct gdb_xml_value new_value;
 
       for (p = attrs; *p != NULL; p += 2)
 	if (!strcmp (attribute->name, p[0]))
@@ -361,9 +342,7 @@ gdb_xml_parser::start_element (const XML_Char *name,
       else
 	parsed_value = xstrdup (val);
 
-      new_value.name = attribute->name;
-      new_value.value = parsed_value;
-      VEC_safe_push (gdb_xml_value_s, attributes, &new_value);
+      attributes.emplace_back (attribute->name, parsed_value);
     }
 
   /* Check for unrecognized attributes.  */
@@ -395,8 +374,6 @@ gdb_xml_parser::start_element (const XML_Char *name,
   scope_level &new_scope = m_scopes.back ();
   new_scope.element = element;
   new_scope.elements = element->children;
-
-  do_cleanups (back_to);
 }
 
 /* Wrapper for gdb_xml_start_element, to prevent throwing exceptions
@@ -803,11 +780,12 @@ struct xinclude_parsing_data
 static void
 xinclude_start_include (struct gdb_xml_parser *parser,
 			const struct gdb_xml_element *element,
-			void *user_data, VEC(gdb_xml_value_s) *attributes)
+			void *user_data,
+			std::vector<gdb_xml_value> &attributes)
 {
   struct xinclude_parsing_data *data
     = (struct xinclude_parsing_data *) user_data;
-  char *href = (char *) xml_find_attribute (attributes, "href")->value;
+  char *href = (char *) xml_find_attribute (attributes, "href")->value.get ();
 
   gdb_xml_debug (parser, _("Processing XInclude of \"%s\""), href);
 
diff --git a/gdb/xml-support.h b/gdb/xml-support.h
index ee5fd52..5947623 100644
--- a/gdb/xml-support.h
+++ b/gdb/xml-support.h
@@ -74,11 +74,13 @@ bool xml_process_xincludes (std::string &result,
 
 struct gdb_xml_value
 {
+  gdb_xml_value (const char *name_, void *value_)
+  : name (name_), value (value_)
+  {}
+
   const char *name;
-  void *value;
+  gdb::unique_xmalloc_ptr<void> value;
 };
-typedef struct gdb_xml_value gdb_xml_value_s;
-DEF_VEC_O(gdb_xml_value_s);
 
 /* The type of an attribute handler.
 
@@ -146,7 +148,7 @@ enum gdb_xml_element_flag
 
 typedef void (gdb_xml_element_start_handler)
      (struct gdb_xml_parser *parser, const struct gdb_xml_element *element,
-      void *user_data, VEC(gdb_xml_value_s) *attributes);
+      void *user_data, std::vector<gdb_xml_value> &attributes);
 
 /* A handler called at the end of an element.
 
@@ -199,8 +201,8 @@ void gdb_xml_error (struct gdb_xml_parser *parser, const char *format, ...)
 /* Find the attribute named NAME in the set of parsed attributes
    ATTRIBUTES.  Returns NULL if not found.  */
 
-struct gdb_xml_value *xml_find_attribute (VEC(gdb_xml_value_s) *attributes,
-					  const char *name);
+struct gdb_xml_value *xml_find_attribute
+  (std::vector<gdb_xml_value> &attributes, const char *name);
 
 /* Parse an integer attribute into a ULONGEST.  */
 
diff --git a/gdb/xml-syscall.c b/gdb/xml-syscall.c
index a53b76f..0ba6d44 100644
--- a/gdb/xml-syscall.c
+++ b/gdb/xml-syscall.c
@@ -227,29 +227,26 @@ syscall_create_syscall_desc (struct syscalls_info *syscalls_info,
 static void
 syscall_start_syscall (struct gdb_xml_parser *parser,
                        const struct gdb_xml_element *element,
-                       void *user_data, VEC(gdb_xml_value_s) *attributes)
+                       void *user_data,
+		       std::vector<gdb_xml_value> &attributes)
 {
   struct syscall_parsing_data *data = (struct syscall_parsing_data *) user_data;
-  struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
-  int len, i;
   /* syscall info.  */
   char *name = NULL;
   int number = 0;
   char *groups = NULL;
 
-  len = VEC_length (gdb_xml_value_s, attributes);
-
-  for (i = 0; i < len; i++)
+  for (const gdb_xml_value &attr : attributes)
     {
-      if (strcmp (attrs[i].name, "name") == 0)
-        name = (char *) attrs[i].value;
-      else if (strcmp (attrs[i].name, "number") == 0)
-        number = * (ULONGEST *) attrs[i].value;
-      else if (strcmp (attrs[i].name, "groups") == 0)
-        groups = (char *) attrs[i].value;
+      if (strcmp (attr.name, "name") == 0)
+        name = (char *) attr.value.get ();
+      else if (strcmp (attr.name, "number") == 0)
+        number = * (ULONGEST *) attr.value.get ();
+      else if (strcmp (attr.name, "groups") == 0)
+        groups = (char *) attr.value.get ();
       else
         internal_error (__FILE__, __LINE__,
-                        _("Unknown attribute name '%s'."), attrs[i].name);
+                        _("Unknown attribute name '%s'."), attr.name);
     }
 
   gdb_assert (name);
diff --git a/gdb/xml-tdesc.c b/gdb/xml-tdesc.c
index 1228375..9190d5f 100644
--- a/gdb/xml-tdesc.c
+++ b/gdb/xml-tdesc.c
@@ -144,9 +144,10 @@ tdesc_end_compatible (struct gdb_xml_parser *parser,
 static void
 tdesc_start_target (struct gdb_xml_parser *parser,
 		    const struct gdb_xml_element *element,
-		    void *user_data, VEC(gdb_xml_value_s) *attributes)
+		    void *user_data, std::vector<gdb_xml_value> &attributes)
 {
-  char *version = (char *) xml_find_attribute (attributes, "version")->value;
+  char *version
+    = (char *) xml_find_attribute (attributes, "version")->value.get ();
 
   if (strcmp (version, "1.0") != 0)
     gdb_xml_error (parser,
@@ -159,10 +160,10 @@ tdesc_start_target (struct gdb_xml_parser *parser,
 static void
 tdesc_start_feature (struct gdb_xml_parser *parser,
 		     const struct gdb_xml_element *element,
-		     void *user_data, VEC(gdb_xml_value_s) *attributes)
+		     void *user_data, std::vector<gdb_xml_value> &attributes)
 {
   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
-  char *name = (char *) xml_find_attribute (attributes, "name")->value;
+  char *name = (char *) xml_find_attribute (attributes, "name")->value.get ();
 
   data->current_feature = tdesc_create_feature (data->tdesc, name);
 }
@@ -173,37 +174,36 @@ tdesc_start_feature (struct gdb_xml_parser *parser,
 static void
 tdesc_start_reg (struct gdb_xml_parser *parser,
 		 const struct gdb_xml_element *element,
-		 void *user_data, VEC(gdb_xml_value_s) *attributes)
+		 void *user_data, std::vector<gdb_xml_value> &attributes)
 {
   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
-  struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
-  int ix = 0, length;
+  int ix = 0;
   char *name, *group;
   const char *type;
   int bitsize, regnum, save_restore;
 
-  length = VEC_length (gdb_xml_value_s, attributes);
+  int length = attributes.size ();
 
-  name = (char *) attrs[ix++].value;
-  bitsize = * (ULONGEST *) attrs[ix++].value;
+  name = (char *) attributes[ix++].value.get ();
+  bitsize = * (ULONGEST *) attributes[ix++].value.get ();
 
-  if (ix < length && strcmp (attrs[ix].name, "regnum") == 0)
-    regnum = * (ULONGEST *) attrs[ix++].value;
+  if (ix < length && strcmp (attributes[ix].name, "regnum") == 0)
+    regnum = * (ULONGEST *) attributes[ix++].value.get ();
   else
     regnum = data->next_regnum;
 
-  if (ix < length && strcmp (attrs[ix].name, "type") == 0)
-    type = (char *) attrs[ix++].value;
+  if (ix < length && strcmp (attributes[ix].name, "type") == 0)
+    type = (char *) attributes[ix++].value.get ();
   else
     type = "int";
 
-  if (ix < length && strcmp (attrs[ix].name, "group") == 0)
-    group = (char *) attrs[ix++].value;
+  if (ix < length && strcmp (attributes[ix].name, "group") == 0)
+    group = (char *) attributes[ix++].value.get ();
   else
     group = NULL;
 
-  if (ix < length && strcmp (attrs[ix].name, "save-restore") == 0)
-    save_restore = * (ULONGEST *) attrs[ix++].value;
+  if (ix < length && strcmp (attributes[ix].name, "save-restore") == 0)
+    save_restore = * (ULONGEST *) attributes[ix++].value.get ();
   else
     save_restore = 1;
 
@@ -225,10 +225,10 @@ tdesc_start_reg (struct gdb_xml_parser *parser,
 static void
 tdesc_start_union (struct gdb_xml_parser *parser,
 		   const struct gdb_xml_element *element,
-		   void *user_data, VEC(gdb_xml_value_s) *attributes)
+		   void *user_data, std::vector<gdb_xml_value> &attributes)
 {
   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
-  char *id = (char *) xml_find_attribute (attributes, "id")->value;
+  char *id = (char *) xml_find_attribute (attributes, "id")->value.get ();
 
   data->current_type = tdesc_create_union (data->current_feature, id);
   data->current_type_size = 0;
@@ -240,10 +240,10 @@ tdesc_start_union (struct gdb_xml_parser *parser,
 static void
 tdesc_start_struct (struct gdb_xml_parser *parser,
 		   const struct gdb_xml_element *element,
-		   void *user_data, VEC(gdb_xml_value_s) *attributes)
+		   void *user_data, std::vector<gdb_xml_value> &attributes)
 {
   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
-  char *id = (char *) xml_find_attribute (attributes, "id")->value;
+  char *id = (char *) xml_find_attribute (attributes, "id")->value.get ();
   struct gdb_xml_value *attr;
 
   tdesc_type_with_fields *type_with_fields
@@ -254,7 +254,7 @@ tdesc_start_struct (struct gdb_xml_parser *parser,
   attr = xml_find_attribute (attributes, "size");
   if (attr != NULL)
     {
-      ULONGEST size = * (ULONGEST *) attr->value;
+      ULONGEST size = * (ULONGEST *) attr->value.get ();
 
       if (size > MAX_FIELD_SIZE)
 	{
@@ -270,12 +270,12 @@ tdesc_start_struct (struct gdb_xml_parser *parser,
 static void
 tdesc_start_flags (struct gdb_xml_parser *parser,
 		   const struct gdb_xml_element *element,
-		   void *user_data, VEC(gdb_xml_value_s) *attributes)
+		   void *user_data, std::vector<gdb_xml_value> &attributes)
 {
   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
-  char *id = (char *) xml_find_attribute (attributes, "id")->value;
+  char *id = (char *) xml_find_attribute (attributes, "id")->value.get ();
   ULONGEST size = * (ULONGEST *)
-    xml_find_attribute (attributes, "size")->value;
+    xml_find_attribute (attributes, "size")->value.get ();
 
   if (size > MAX_FIELD_SIZE)
     {
@@ -291,12 +291,12 @@ tdesc_start_flags (struct gdb_xml_parser *parser,
 static void
 tdesc_start_enum (struct gdb_xml_parser *parser,
 		  const struct gdb_xml_element *element,
-		  void *user_data, VEC(gdb_xml_value_s) *attributes)
+		  void *user_data, std::vector<gdb_xml_value> &attributes)
 {
   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
-  char *id = (char *) xml_find_attribute (attributes, "id")->value;
+  char *id = (char *) xml_find_attribute (attributes, "id")->value.get ();
   int size = * (ULONGEST *)
-    xml_find_attribute (attributes, "size")->value;
+    xml_find_attribute (attributes, "size")->value.get ();
 
   if (size > MAX_FIELD_SIZE)
     {
@@ -315,7 +315,7 @@ tdesc_start_enum (struct gdb_xml_parser *parser,
 static void
 tdesc_start_field (struct gdb_xml_parser *parser,
 		   const struct gdb_xml_element *element,
-		   void *user_data, VEC(gdb_xml_value_s) *attributes)
+		   void *user_data, std::vector<gdb_xml_value> &attributes)
 {
   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
   struct gdb_xml_value *attr;
@@ -323,12 +323,12 @@ tdesc_start_field (struct gdb_xml_parser *parser,
   char *field_name, *field_type_id;
   int start, end;
 
-  field_name = (char *) xml_find_attribute (attributes, "name")->value;
+  field_name = (char *) xml_find_attribute (attributes, "name")->value.get ();
 
   attr = xml_find_attribute (attributes, "type");
   if (attr != NULL)
     {
-      field_type_id = (char *) attr->value;
+      field_type_id = (char *) attr->value.get ();
       field_type = tdesc_named_type (data->current_feature, field_type_id);
     }
   else
@@ -340,7 +340,7 @@ tdesc_start_field (struct gdb_xml_parser *parser,
   attr = xml_find_attribute (attributes, "start");
   if (attr != NULL)
     {
-      ULONGEST ul_start = * (ULONGEST *) attr->value;
+      ULONGEST ul_start = * (ULONGEST *) attr->value.get ();
 
       if (ul_start > MAX_FIELD_BITSIZE)
 	{
@@ -356,7 +356,7 @@ tdesc_start_field (struct gdb_xml_parser *parser,
   attr = xml_find_attribute (attributes, "end");
   if (attr != NULL)
     {
-      ULONGEST ul_end = * (ULONGEST *) attr->value;
+      ULONGEST ul_end = * (ULONGEST *) attr->value.get ();
 
       if (ul_end > MAX_FIELD_BITSIZE)
 	{
@@ -444,7 +444,7 @@ tdesc_start_field (struct gdb_xml_parser *parser,
 static void
 tdesc_start_enum_value (struct gdb_xml_parser *parser,
 			const struct gdb_xml_element *element,
-			void *user_data, VEC(gdb_xml_value_s) *attributes)
+			void *user_data, std::vector<gdb_xml_value> &attributes)
 {
   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
   struct gdb_xml_value *attr;
@@ -452,10 +452,10 @@ tdesc_start_enum_value (struct gdb_xml_parser *parser,
   ULONGEST ul_value;
   int value;
 
-  field_name = (char *) xml_find_attribute (attributes, "name")->value;
+  field_name = (char *) xml_find_attribute (attributes, "name")->value.get ();
 
   attr = xml_find_attribute (attributes, "value");
-  ul_value = * (ULONGEST *) attr->value;
+  ul_value = * (ULONGEST *) attr->value.get ();
   if (ul_value > INT_MAX)
     {
       gdb_xml_error (parser,
@@ -473,17 +473,16 @@ tdesc_start_enum_value (struct gdb_xml_parser *parser,
 static void
 tdesc_start_vector (struct gdb_xml_parser *parser,
 		    const struct gdb_xml_element *element,
-		    void *user_data, VEC(gdb_xml_value_s) *attributes)
+		    void *user_data, std::vector<gdb_xml_value> &attributes)
 {
   struct tdesc_parsing_data *data = (struct tdesc_parsing_data *) user_data;
-  struct gdb_xml_value *attrs = VEC_address (gdb_xml_value_s, attributes);
   struct tdesc_type *field_type;
   char *id, *field_type_id;
   ULONGEST count;
 
-  id = (char *) attrs[0].value;
-  field_type_id = (char *) attrs[1].value;
-  count = * (ULONGEST *) attrs[2].value;
+  id = (char *) attributes[0].value.get ();
+  field_type_id = (char *) attributes[1].value.get ();
+  count = * (ULONGEST *) attributes[2].value.get ();
 
   if (count > MAX_VECTOR_SIZE)
     {