gdbserver: fix the declared type of register_status in regcache

The register_status field of regcache is declared as `unsigned char *`.
This is incorrect, because `enum register_status` from
gdbsupport/common-regcache.h is based on signed char and
REG_UNAVAILABLE is defined as -1.  Fix the declared type.

Now that we are modifying the declaration, also use a unique_ptr
and make the field private.

The get/set methods already use the correct type, but we update cast
operations in two places.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

2 files changed, 18 insertions, 14 deletions

diff --git a/gdbserver/regcache.cc b/gdbserver/regcache.cc
index 06ac372..ee0c1b3 100644
--- a/gdbserver/regcache.cc
+++ b/gdbserver/regcache.cc
@@ -130,8 +130,8 @@ regcache::regcache (const target_desc *tdesc)
      garbage.  */
   this->registers
     = (unsigned char *) xmalloc (tdesc->registers_size);
-  this->register_status
-    = (unsigned char *) xmalloc (tdesc->reg_defs.size ());
+  size_t num_regs = tdesc->reg_defs.size ();
+  m_register_status.reset (new enum register_status[num_regs]);
   reset (REG_UNKNOWN);
 }
 
@@ -139,7 +139,6 @@ regcache::~regcache ()
 {
   if (registers_owned)
     free (registers);
-  free (register_status);
 }
 
 #endif
@@ -152,8 +151,8 @@ regcache::reset (enum register_status status)
      of garbage.  */
   memset (this->registers, 0, this->tdesc->registers_size);
 #ifndef IN_PROCESS_AGENT
-  if (this->register_status != nullptr)
-    memset (this->register_status, status, this->tdesc->reg_defs.size ());
+  for (int i = 0; i < this->tdesc->reg_defs.size (); i++)
+    set_register_status (i, status);
 #endif
 }
 
@@ -166,8 +165,8 @@ regcache::copy_from (regcache *src)
 
   memcpy (this->registers, src->registers, src->tdesc->registers_size);
 #ifndef IN_PROCESS_AGENT
-  if (this->register_status != nullptr && src->register_status != nullptr)
-    memcpy (this->register_status, src->register_status,
+  if (m_register_status != nullptr && src->m_register_status != nullptr)
+    memcpy (m_register_status.get (), src->m_register_status.get (),
 	    src->tdesc->reg_defs.size ());
 #endif
   this->registers_fetched = src->registers_fetched;
@@ -477,8 +476,8 @@ regcache::get_register_status (int regnum) const
 {
 #ifndef IN_PROCESS_AGENT
   gdb_assert (regnum >= 0 && regnum < tdesc->reg_defs.size ());
-  if (register_status != nullptr)
-    return (enum register_status) (register_status[regnum]);
+  if (m_register_status != nullptr)
+    return m_register_status[regnum];
   else
     return REG_VALID;
 #else
@@ -491,8 +490,8 @@ regcache::set_register_status (int regnum, enum register_status status)
 {
 #ifndef IN_PROCESS_AGENT
   gdb_assert (regnum >= 0 && regnum < tdesc->reg_defs.size ());
-  if (register_status != nullptr)
-    register_status[regnum] = status;
+  if (m_register_status != nullptr)
+    m_register_status[regnum] = status;
 #endif
 }
 
diff --git a/gdbserver/regcache.h b/gdbserver/regcache.h
index f5db119..96d2a4d 100644
--- a/gdbserver/regcache.h
+++ b/gdbserver/regcache.h
@@ -20,6 +20,7 @@
 #define GDBSERVER_REGCACHE_H
 
 #include "gdbsupport/common-regcache.h"
+#include <memory>
 
 struct thread_info;
 struct target_desc;
@@ -43,9 +44,6 @@ struct regcache : public reg_buffer_common
   bool registers_owned = false;
   unsigned char *registers = nullptr;
 #ifndef IN_PROCESS_AGENT
-  /* See gdbsupport/common-regcache.h.  */
-  unsigned char *register_status = nullptr;
-
   /* Construct a regcache using the register layout described by TDESC.
 
      The regcache dynamically allocates its register buffer.  */
@@ -90,6 +88,13 @@ struct regcache : public reg_buffer_common
 
   /* Copy the contents of SRC into this regcache.  */
   void copy_from (regcache *src);
+
+private:
+
+#ifndef IN_PROCESS_AGENT
+  /* See gdbsupport/common-regcache.h.  */
+  std::unique_ptr<enum register_status[]> m_register_status;
+#endif
 };
 
 regcache *get_thread_regcache (thread_info *thread, bool fetch = true);