target_ops::beneath -> target_ops::beneath()

This changes target_ops::beneath from a pointer to a method, and
adjusts all references throughout.  The idea here is to make it easier
to change the target stack representation from an intrusive singly
linked list to something else without leaking implementation details
throughout.

The commit does not change the representation yet, that will be done
in a following patch.  That is why a new target_ops::m_beneath field
appears here.  That new field isn't really documented properly or made
private, simply because it will be removed shortly.

Note that target_ops::beneath() is essentially the same as the current
find_target_beneath routine.  The following patch will eliminate the
latter.

gdb/ChangeLog:
2018-06-07  Pedro Alves  <palves@redhat.com>

	* target.h (target_ops) <beneath>: Now a method.  All references
	updated.
	(target_ops) <m_beneath>: New.
	* target.c (target_ops::beneath): New.
	* corelow.c: Adjust all references to target_ops::beneath.
	* linux-thread-db.c: Likewise.
	* make-target-delegates: Likewise.
	* record-btrace.c: Likewise.
	* record-full.c: Likewise.
	* remote.c: Likewise.
	* target.c: Likewise.
	* target-delegates.c: Regenerate.

1 files changed, 37 insertions, 54 deletions

diff --git a/gdb/target.c b/gdb/target.c
index 13f7e68..c8fa8e1 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -268,9 +268,7 @@ default_child_has_execution (ptid_t the_ptid)
 int
 target_has_all_memory_1 (void)
 {
-  struct target_ops *t;
-
-  for (t = current_top_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
     if (t->has_all_memory ())
       return 1;
 
@@ -280,9 +278,7 @@ target_has_all_memory_1 (void)
 int
 target_has_memory_1 (void)
 {
-  struct target_ops *t;
-
-  for (t = current_top_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
     if (t->has_memory ())
       return 1;
 
@@ -292,9 +288,7 @@ target_has_memory_1 (void)
 int
 target_has_stack_1 (void)
 {
-  struct target_ops *t;
-
-  for (t = current_top_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
     if (t->has_stack ())
       return 1;
 
@@ -304,9 +298,7 @@ target_has_stack_1 (void)
 int
 target_has_registers_1 (void)
 {
-  struct target_ops *t;
-
-  for (t = current_top_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
     if (t->has_registers ())
       return 1;
 
@@ -316,9 +308,7 @@ target_has_registers_1 (void)
 int
 target_has_execution_1 (ptid_t the_ptid)
 {
-  struct target_ops *t;
-
-  for (t = current_top_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
     if (t->has_execution (the_ptid))
       return 1;
 
@@ -654,7 +644,7 @@ push_target (struct target_ops *t)
   struct target_ops **cur;
 
   /* Find the proper stratum to install this target in.  */
-  for (cur = &g_current_top_target; (*cur) != NULL; cur = &(*cur)->beneath)
+  for (cur = &g_current_top_target; (*cur) != NULL; cur = &(*cur)->m_beneath)
     {
       if ((int) (t->to_stratum) >= (int) (*cur)->to_stratum)
 	break;
@@ -669,13 +659,13 @@ push_target (struct target_ops *t)
          and un-hook it from the stack.  */
       struct target_ops *tmp = (*cur);
 
-      (*cur) = (*cur)->beneath;
-      tmp->beneath = NULL;
+      (*cur) = (*cur)->m_beneath;
+      tmp->m_beneath = NULL;
       target_close (tmp);
     }
 
   /* We have removed all targets in our stratum, now add the new one.  */
-  t->beneath = (*cur);
+  t->m_beneath = (*cur);
   (*cur) = t;
 }
 
@@ -695,7 +685,7 @@ unpush_target (struct target_ops *t)
   /* Look for the specified target.  Note that we assume that a target
      can only occur once in the target stack.  */
 
-  for (cur = &g_current_top_target; (*cur) != NULL; cur = &(*cur)->beneath)
+  for (cur = &g_current_top_target; (*cur) != NULL; cur = &(*cur)->m_beneath)
     {
       if ((*cur) == t)
 	break;
@@ -708,8 +698,8 @@ unpush_target (struct target_ops *t)
 
   /* Unchain the target.  */
   tmp = (*cur);
-  (*cur) = (*cur)->beneath;
-  tmp->beneath = NULL;
+  (*cur) = (*cur)->m_beneath;
+  tmp->m_beneath = NULL;
 
   /* Finally close the target.  Note we do this after unchaining, so
      any target method calls from within the target_close
@@ -761,9 +751,9 @@ pop_all_targets (void)
 int
 target_is_pushed (struct target_ops *t)
 {
-  struct target_ops *cur;
-
-  for (cur = current_top_target (); cur != NULL; cur = cur->beneath)
+  for (target_ops *cur = current_top_target ();
+       cur != NULL;
+       cur = cur->beneath ())
     if (cur == t)
       return 1;
 
@@ -1060,7 +1050,7 @@ raw_memory_xfer_partial (struct target_ops *ops, gdb_byte *readbuf,
       if (ops->has_all_memory ())
 	break;
 
-      ops = ops->beneath;
+      ops = ops->beneath ();
     }
   while (ops != NULL);
 
@@ -1968,14 +1958,13 @@ target_remove_breakpoint (struct gdbarch *gdbarch,
 static void
 info_target_command (const char *args, int from_tty)
 {
-  struct target_ops *t;
   int has_all_mem = 0;
 
   if (symfile_objfile != NULL)
     printf_unfiltered (_("Symbols from \"%s\".\n"),
 		       objfile_name (symfile_objfile));
 
-  for (t = current_top_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
     {
       if (!t->has_memory ())
 	continue;
@@ -2405,9 +2394,7 @@ target_search_memory (CORE_ADDR start_addr, ULONGEST search_space_len,
 void
 target_require_runnable (void)
 {
-  struct target_ops *t;
-
-  for (t = current_top_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
     {
       /* If this target knows how to create a new program, then
 	 assume we will still be able to after killing the current
@@ -2497,7 +2484,7 @@ struct target_ops *
 find_attach_target (void)
 {
   /* If a target on the current stack can attach, use it.  */
-  for (target_ops *t = current_top_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
     {
       if (t->can_attach ())
 	return t;
@@ -2513,7 +2500,7 @@ struct target_ops *
 find_run_target (void)
 {
   /* If a target on the current stack can run, use it.  */
-  for (target_ops *t = current_top_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
     {
       if (t->can_create_inferior ())
 	return t;
@@ -2543,7 +2530,7 @@ target_info_proc (const char *args, enum info_proc_what what)
   if (t == NULL)
     t = find_default_run_target (NULL);
 
-  for (; t != NULL; t = t->beneath)
+  for (; t != NULL; t = t->beneath ())
     {
       if (t->info_proc (args, what))
 	{
@@ -2633,6 +2620,14 @@ target_thread_address_space (ptid_t ptid)
   return aspace;
 }
 
+/* See target.h.  */
+
+target_ops *
+target_ops::beneath () const
+{
+  return m_beneath;
+}
+
 void
 target_ops::close ()
 {
@@ -2672,9 +2667,7 @@ target_ops::can_run ()
 int
 target_can_run ()
 {
-  struct target_ops *t;
-
-  for (t = current_top_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
     {
       if (t->can_run ())
 	return 1;
@@ -2856,9 +2849,7 @@ target_fileio_open_1 (struct inferior *inf, const char *filename,
 		      int flags, int mode, int warn_if_slow,
 		      int *target_errno)
 {
-  struct target_ops *t;
-
-  for (t = default_fileio_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = default_fileio_target (); t != NULL; t = t->beneath ())
     {
       int fd = t->fileio_open (inf, filename, flags, mode,
 			       warn_if_slow, target_errno);
@@ -3014,9 +3005,7 @@ int
 target_fileio_unlink (struct inferior *inf, const char *filename,
 		      int *target_errno)
 {
-  struct target_ops *t;
-
-  for (t = default_fileio_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = default_fileio_target (); t != NULL; t = t->beneath ())
     {
       int ret = t->fileio_unlink (inf, filename, target_errno);
 
@@ -3042,9 +3031,7 @@ gdb::optional<std::string>
 target_fileio_readlink (struct inferior *inf, const char *filename,
 			int *target_errno)
 {
-  struct target_ops *t;
-
-  for (t = default_fileio_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = default_fileio_target (); t != NULL; t = t->beneath ())
     {
       gdb::optional<std::string> ret
 	= t->fileio_readlink (inf, filename, target_errno);
@@ -3231,7 +3218,7 @@ default_thread_architecture (struct target_ops *ops, ptid_t ptid)
 struct target_ops *
 find_target_beneath (struct target_ops *t)
 {
-  return t->beneath;
+  return t->beneath ();
 }
 
 /* See target.h.  */
@@ -3239,9 +3226,7 @@ find_target_beneath (struct target_ops *t)
 struct target_ops *
 find_target_at (enum strata stratum)
 {
-  struct target_ops *t;
-
-  for (t = current_top_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
     if (t->to_stratum == stratum)
       return t;
 
@@ -3370,7 +3355,7 @@ dummy_target::info () const
 const target_info &
 debug_target::info () const
 {
-  return beneath->info ();
+  return beneath ()->info ();
 }
 
 
@@ -3906,11 +3891,9 @@ flash_erase_command (const char *cmd, int from_tty)
 static void
 maintenance_print_target_stack (const char *cmd, int from_tty)
 {
-  struct target_ops *t;
-
   printf_filtered (_("The current target stack is:\n"));
 
-  for (t = current_top_target (); t != NULL; t = t->beneath)
+  for (target_ops *t = current_top_target (); t != NULL; t = t->beneath ())
     {
       if (t->to_stratum == debug_stratum)
 	continue;