[nto] Fix nto target stopped by watchpoint.

Fix 'stopped by watchpoint' detection: add inferior data, use inferior data
for storing last stopped flags needed for detection.

gdb/ChangeLog:

	* nto-procfs.c (procfs_wait): Set stopped_flags nad stopped_pc.
	(procfs_stopped_by_watchpoint): Use flags stored in inferior data.
	* nto-tdep.c (nto_new_inferior_data_reg): New definition.
	(nto_new_inferior_data, nto_inferior_data_cleanup, nto_inferior_data):
	New functions.
	(_initialize_nto_tdep): New forward declaration, new function.
	* nto-tdep.h (struct nto_inferior_data): New struct.
	(nto_inferior_data): New function declaration.

4 files changed, 96 insertions, 1 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index e54695046c6..277a0ceadd7 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,14 @@
+2015-10-21  Aleksandar Ristovski  <aristovski@qnx.com>
+
+	* nto-procfs.c (procfs_wait): Set stopped_flags nad stopped_pc.
+	(procfs_stopped_by_watchpoint): Use flags stored in inferior data.
+	* nto-tdep.c (nto_new_inferior_data_reg): New definition.
+	(nto_new_inferior_data, nto_inferior_data_cleanup, nto_inferior_data):
+	New functions.
+	(_initialize_nto_tdep): New forward declaration, new function.
+	* nto-tdep.h (struct nto_inferior_data): New struct.
+	(nto_inferior_data): New function declaration.
+
 2015-10-20  Jan Kratochvil  <jan.kratochvil@redhat.com>
 
 	* findvar.c (address_from_register): Check REGNUM validity.
diff --git a/gdb/nto-procfs.c b/gdb/nto-procfs.c
index 82b428c0783..6ab78e35b0a 100644
--- a/gdb/nto-procfs.c
+++ b/gdb/nto-procfs.c
@@ -784,6 +784,9 @@ procfs_wait (struct target_ops *ops,
       devctl (ctl_fd, DCMD_PROC_STATUS, &status, sizeof (status), 0);
     }
 
+  nto_inferior_data (NULL)->stopped_flags = status.flags;
+  nto_inferior_data (NULL)->stopped_pc = status.ip;
+
   if (status.flags & _DEBUG_FLAG_SSTEP)
     {
       ourstatus->kind = TARGET_WAITKIND_STOPPED;
@@ -1626,5 +1629,21 @@ procfs_insert_hw_watchpoint (struct target_ops *self,
 static int
 procfs_stopped_by_watchpoint (struct target_ops *ops)
 {
-  return 0;
+  /* NOTE: nto_stopped_by_watchpoint will be called ONLY while we are
+     stopped due to a SIGTRAP.  This assumes gdb works in 'all-stop' mode;
+     future gdb versions will likely run in 'non-stop' mode in which case
+     we will have to store/examine statuses per thread in question.
+     Until then, this will work fine.  */
+
+  struct inferior *inf = current_inferior ();
+  struct nto_inferior_data *inf_data;
+
+  gdb_assert (inf != NULL);
+
+  inf_data = nto_inferior_data (inf);
+
+  return inf_data->stopped_flags
+	 & (_DEBUG_FLAG_TRACE_RD
+	    | _DEBUG_FLAG_TRACE_WR
+	    | _DEBUG_FLAG_TRACE_MODIFY);
 }
diff --git a/gdb/nto-tdep.c b/gdb/nto-tdep.c
index 62eb88afdb2..e50d3021972 100644
--- a/gdb/nto-tdep.c
+++ b/gdb/nto-tdep.c
@@ -46,6 +46,8 @@ static char default_nto_target[] = "";
 
 struct nto_target_ops current_nto_target;
 
+static const struct inferior_data *nto_inferior_data_reg;
+
 static char *
 nto_target (void)
 {
@@ -477,3 +479,53 @@ nto_read_auxv_from_initial_stack (CORE_ADDR initial_stack, gdb_byte *readbuf,
     }
   return len_read;
 }
+
+/* Allocate new nto_inferior_data object.  */
+
+static struct nto_inferior_data *
+nto_new_inferior_data (void)
+{
+  struct nto_inferior_data *const inf_data
+    = XCNEW (struct nto_inferior_data);
+
+  return inf_data;
+}
+
+/* Free inferior data.  */
+
+static void
+nto_inferior_data_cleanup (struct inferior *const inf, void *const dat)
+{
+  xfree (dat);
+}
+
+/* Return nto_inferior_data for the given INFERIOR.  If not yet created,
+   construct it.  */
+
+struct nto_inferior_data *
+nto_inferior_data (struct inferior *const inferior)
+{
+  struct inferior *const inf = inferior ? inferior : current_inferior ();
+  struct nto_inferior_data *inf_data;
+
+  gdb_assert (inf != NULL);
+
+  inf_data = inferior_data (inf, nto_inferior_data_reg);
+  if (inf_data == NULL)
+    {
+      set_inferior_data (inf, nto_inferior_data_reg,
+			 (inf_data = nto_new_inferior_data ()));
+    }
+
+  return inf_data;
+}
+
+/* Provide a prototype to silence -Wmissing-prototypes.  */
+extern initialize_file_ftype _initialize_nto_tdep;
+
+void
+_initialize_nto_tdep (void)
+{
+  nto_inferior_data_reg
+    = register_inferior_data_with_cleanup (NULL, nto_inferior_data_cleanup);
+}
diff --git a/gdb/nto-tdep.h b/gdb/nto-tdep.h
index d029f073ddd..6ed9da0c2ce 100644
--- a/gdb/nto-tdep.h
+++ b/gdb/nto-tdep.h
@@ -142,6 +142,16 @@ struct private_thread_info
   char name[1];
 };
 
+/* Per-inferior data, common for both procfs and remote.  */
+struct nto_inferior_data
+{
+  /* Last stopped flags result from wait function */
+  unsigned int stopped_flags;
+
+  /* Last known stopped PC */
+  CORE_ADDR stopped_pc;
+};
+
 /* Generic functions in nto-tdep.c.  */
 
 void nto_init_solib_absolute_prefix (void);
@@ -171,4 +181,7 @@ char *nto_extra_thread_info (struct target_ops *self, struct thread_info *);
 LONGEST nto_read_auxv_from_initial_stack (CORE_ADDR inital_stack,
 					  gdb_byte *readbuf,
 					  LONGEST len, size_t sizeof_auxv_t);
+
+struct nto_inferior_data *nto_inferior_data (struct inferior *inf);
+
 #endif