[RFC PATCH 1/3] Implemement support for groups of syscalls in the xml-syscall interface.

[Gabriel Krisman Bertazi <gabriel at krisman dot be>]

This implements support for groups of syscalls in the xml-syscall
interface.

It is done by maintaining a list of syscall_group_desc for each syscall
group inside the syscalls_info structure.  Inside each
syscall_group_desc we have a vector of pointers to the syscalls that are
part of that group.

I also experimented with storing the group info inside each syscall_desc
element, but that wasn't very practical when dealing with syscalls that
are part of more than one group. :)

gdb/

	* syscalls/gdb-syscalls.dtd: Include group attribute to the
	syscall element.
	* xml-syscall.c (get_syscall_names_by_group): New.
	(get_syscall_group_names): New.
	(struct syscall_group_desc): New structure to store group data.
	(struct syscalls_info): Include field to store the group list.
	(sysinfo_free_syscall_group_desc): New.
	(free_syscalls_info): Free group list.
	(syscall_group_create_syscall_group_desc): New.
	(syscall_group_add_syscall): New.
	(syscall_create_syscall_desc): Add syscall to its groups.
	(syscall_start_syscall): Load group attribute.
	(syscall_group_get_group_by_name): New.
	(xml_list_of_syscalls): Add filter by group name.
	(xml_list_of_groups): New.
	(get_syscall_names): Call xml_list_of_syscalls with a NULL group
	filter string.
	* xml-syscall.h (get_syscall_names_by_group): Export function
	to retrieve a list of syscalls filtered by the group name.
	(get_syscall_group_names): Export function to retrieve the list of
	syscall groups.
---
 gdb/syscalls/gdb-syscalls.dtd |   1 +
 gdb/xml-syscall.c             | 183 ++++++++++++++++++++++++++++++++++++++++--
 gdb/xml-syscall.h             |  12 +++
 3 files changed, 190 insertions(+), 6 deletions(-)

diff --git a/gdb/syscalls/gdb-syscalls.dtd b/gdb/syscalls/gdb-syscalls.dtd
index 3ad3625..5255869 100644
--- a/gdb/syscalls/gdb-syscalls.dtd
+++ b/gdb/syscalls/gdb-syscalls.dtd
@@ -10,5 +10,6 @@
 
 <!ELEMENT syscall		EMPTY>
 <!ATTLIST syscall
+	groups			CDATA	#OPTIONAL
 	name			CDATA	#REQUIRED
 	number			CDATA	#REQUIRED>
diff --git a/gdb/xml-syscall.c b/gdb/xml-syscall.c
index 3824468..39d3f02 100644
--- a/gdb/xml-syscall.c
+++ b/gdb/xml-syscall.c
@@ -76,6 +76,20 @@ get_syscall_names (void)
   return NULL;
 }
 
+const char **
+get_syscall_names_by_group (const char *group)
+{
+  syscall_warn_user ();
+  return NULL;
+}
+
+const char **
+get_syscall_group_names (void)
+{
+  syscall_warn_user ();
+  return NULL;
+}
+
 #else /* ! HAVE_LIBEXPAT */
 
 /* Variable that will hold the last known data-directory.  This is useful to
@@ -95,12 +109,29 @@ typedef struct syscall_desc
 } *syscall_desc_p;
 DEF_VEC_P(syscall_desc_p);
 
+/* Structure of a syscall group.  */
+typedef struct syscall_group_desc
+{
+  /* The group name.  */
+
+  char *name;
+
+  /* The syscalls that are part of the group.  */
+
+  VEC(syscall_desc_p) *syscalls;
+} *syscall_group_desc_p;
+DEF_VEC_P(syscall_group_desc_p);
+
 /* Structure that represents syscalls information.  */
 struct syscalls_info
 {
   /* The syscalls.  */
 
   VEC(syscall_desc_p) *syscalls;
+
+  /* The syscall groups.  */
+
+  VEC(syscall_group_desc_p) *groups;
 };
 
 /* Callback data for syscall information parsing.  */
@@ -134,17 +165,32 @@ sysinfo_free_syscalls_desc (struct syscall_desc *sd)
 }
 
 static void
+sysinfo_free_syscall_group_desc (struct syscall_group_desc *sd)
+{
+  VEC_free (syscall_desc_p, sd->syscalls);
+  xfree (sd->name);
+}
+
+static void
 free_syscalls_info (void *arg)
 {
   struct syscalls_info *sysinfo = arg;
   struct syscall_desc *sysdesc;
+  struct syscall_group_desc *groupdesc;
   int i;
 
   for (i = 0;
        VEC_iterate (syscall_desc_p, sysinfo->syscalls, i, sysdesc);
        i++)
     sysinfo_free_syscalls_desc (sysdesc);
+
+  for (i = 0;
+       VEC_iterate (syscall_group_desc_p, sysinfo->groups, i, groupdesc);
+       i++)
+    sysinfo_free_syscall_group_desc (groupdesc);
+
   VEC_free (syscall_desc_p, sysinfo->syscalls);
+  VEC_free (syscall_group_desc_p, sysinfo->groups);
 
   xfree (sysinfo);
 }
@@ -155,15 +201,59 @@ make_cleanup_free_syscalls_info (struct syscalls_info *sysinfo)
   return make_cleanup (free_syscalls_info, sysinfo);
 }
 
+static struct syscall_group_desc *
+syscall_group_create_syscall_group_desc (struct syscalls_info *sysinfo,
+					 const char *group)
+{
+  struct syscall_group_desc *groupdesc = XCNEW (struct syscall_group_desc);
+
+  groupdesc->name = strdup (group);
+
+  VEC_safe_push (syscall_group_desc_p, sysinfo->groups, groupdesc);
+
+  return groupdesc;
+}
+
+static void
+syscall_group_add_syscall (struct syscalls_info *sysinfo,
+			   struct syscall_desc *syscall,
+			   const char *group)
+{
+  struct syscall_group_desc *groupdesc;
+  int i;
+
+  /* Search for an existing group.  */
+  for (i = 0;
+       VEC_iterate (syscall_group_desc_p, sysinfo->groups, i, groupdesc);
+       i++)
+    if (strcmp (groupdesc->name, group) == 0)
+      break;
+
+  if (groupdesc == NULL)
+    {
+      /* Create new group.  */
+      groupdesc = syscall_group_create_syscall_group_desc (sysinfo, group);
+    }
+
+  VEC_safe_push (syscall_desc_p, groupdesc->syscalls, syscall);
+}
+
 static void
 syscall_create_syscall_desc (struct syscalls_info *sysinfo,
-                             const char *name, int number)
+			     const char *name, int number,
+			     char *groups)
 {
   struct syscall_desc *sysdesc = XCNEW (struct syscall_desc);
+  char *group;
 
   sysdesc->name = xstrdup (name);
   sysdesc->number = number;
 
+  /*  Add syscall to its groups.  */
+  if (groups != NULL)
+    for (group = strtok (groups, ","); group; group = strtok (NULL, ","))
+      syscall_group_add_syscall (sysinfo, sysdesc, group);
+
   VEC_safe_push (syscall_desc_p, sysinfo->syscalls, sysdesc);
 }
 
@@ -179,6 +269,7 @@ syscall_start_syscall (struct gdb_xml_parser *parser,
   /* syscall info.  */
   char *name = NULL;
   int number = 0;
+  char *groups = NULL;
 
   len = VEC_length (gdb_xml_value_s, attributes);
 
@@ -188,13 +279,15 @@ syscall_start_syscall (struct gdb_xml_parser *parser,
         name = 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 = attrs[i].value;
       else
         internal_error (__FILE__, __LINE__,
                         _("Unknown attribute name '%s'."), attrs[i].name);
     }
 
   gdb_assert (name);
-  syscall_create_syscall_desc (data->sysinfo, name, number);
+  syscall_create_syscall_desc (data->sysinfo, name, number, groups);
 }
 
 
@@ -202,6 +295,7 @@ syscall_start_syscall (struct gdb_xml_parser *parser,
 static const struct gdb_xml_attribute syscall_attr[] = {
   { "number", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
   { "name", GDB_XML_AF_NONE, NULL, NULL },
+  { "groups", GDB_XML_AF_OPTIONAL, NULL, NULL },
   { NULL, GDB_XML_AF_NONE, NULL, NULL }
 };
 
@@ -315,6 +409,26 @@ init_sysinfo (void)
   my_gdb_datadir = xstrdup (gdb_datadir);
 }
 
+static struct syscall_group_desc *
+syscall_group_get_group_by_name (const struct syscalls_info *sysinfo,
+				 const char *group)
+{
+  struct syscall_group_desc *groupdesc;
+  int i;
+
+  if (sysinfo == NULL)
+    return NULL;
+
+   /* Search for existing group.  */
+  for (i = 0;
+       VEC_iterate (syscall_group_desc_p, sysinfo->groups, i, groupdesc);
+       i++)
+    if (strcmp (groupdesc->name, group) == 0)
+      return groupdesc;
+
+  return NULL;
+}
+
 static int
 xml_get_syscall_number (const struct syscalls_info *sysinfo,
                         const char *syscall_name)
@@ -356,8 +470,10 @@ xml_get_syscall_name (const struct syscalls_info *sysinfo,
 }
 
 static const char **
-xml_list_of_syscalls (const struct syscalls_info *sysinfo)
+xml_list_of_syscalls (const struct syscalls_info *sysinfo,
+		      const char *group_filter)
 {
+  VEC(syscall_desc_p) *syscall_list = NULL;
   struct syscall_desc *sysdesc;
   const char **names = NULL;
   int nsyscalls;
@@ -366,11 +482,26 @@ xml_list_of_syscalls (const struct syscalls_info *sysinfo)
   if (sysinfo == NULL)
     return NULL;
 
-  nsyscalls = VEC_length (syscall_desc_p, sysinfo->syscalls);
+  if (group_filter == NULL)
+    {
+      /* We use the general list that includes every syscall.  */
+      syscall_list = sysinfo->syscalls;
+    }
+  else
+    {
+      struct syscall_group_desc *groupdesc;
+
+      groupdesc = syscall_group_get_group_by_name (sysinfo,
+						   group_filter);
+      if (groupdesc != NULL)
+	syscall_list = groupdesc->syscalls;
+    }
+
+  nsyscalls = VEC_length (syscall_desc_p, syscall_list);
   names = xmalloc ((nsyscalls + 1) * sizeof (char *));
 
   for (i = 0;
-       VEC_iterate (syscall_desc_p, sysinfo->syscalls, i, sysdesc);
+       VEC_iterate (syscall_desc_p, syscall_list, i, sysdesc);
        i++)
     names[i] = sysdesc->name;
 
@@ -379,6 +510,30 @@ xml_list_of_syscalls (const struct syscalls_info *sysinfo)
   return names;
 }
 
+static const char **
+xml_list_of_groups (const struct syscalls_info *sysinfo)
+{
+  struct syscall_group_desc *groupdesc;
+  const char **names = NULL;
+  int i;
+  int ngroups;
+
+  if (sysinfo == NULL)
+    return NULL;
+
+  ngroups = VEC_length (syscall_group_desc_p, sysinfo->groups);
+  names = xmalloc ((ngroups + 1) * sizeof (char *));
+
+  for (i = 0;
+       VEC_iterate (syscall_group_desc_p, sysinfo->groups, i, groupdesc);
+       i++)
+    names[i] = groupdesc->name;
+
+  names[i] = NULL;
+
+  return names;
+}
+
 void
 set_xml_syscall_file_name (const char *name)
 {
@@ -410,7 +565,23 @@ get_syscall_names (void)
 {
   init_sysinfo ();
 
-  return xml_list_of_syscalls (sysinfo);
+  return xml_list_of_syscalls (sysinfo, NULL);
+}
+
+const char **
+get_syscall_names_by_group (const char *group)
+{
+  init_sysinfo ();
+
+  return xml_list_of_syscalls (sysinfo, group);
+}
+
+const char **
+get_syscall_group_names (void)
+{
+  init_sysinfo ();
+
+  return xml_list_of_groups (sysinfo);
 }
 
 #endif /* ! HAVE_LIBEXPAT */
diff --git a/gdb/xml-syscall.h b/gdb/xml-syscall.h
index dff389d..903a758 100644
--- a/gdb/xml-syscall.h
+++ b/gdb/xml-syscall.h
@@ -47,4 +47,16 @@ void get_syscall_by_name (const char *syscall_name, struct syscall *s);
 
 const char **get_syscall_names (void);
 
+/* Function used to retrieve the list of syscalls of a given group in
+   the system.  If group is NULL, return every syscall. The vector is
+   returned as an array of strings terminated by a NULL element.
+   Returns the list of syscalls of a group, or NULL otherwise.  */
+
+const char **get_syscall_names_by_group (const char *group);
+
+/* Function used to retrieve the list of syscall groups in the system.
+   Returns an array of strings terminated by a NULL element.  */
+
+const char **get_syscall_group_names (void);
+
 #endif /* XML_SYSCALL_H */
-- 
1.9.3