gdbserver: turn target op 'read_offsets' into a method

gdbserver/ChangeLog:
2020-02-20  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>

	Turn process_stratum_target's read_offsets op into a method of
	process_target.

	* target.h (struct process_stratum_target): Remove the target op.
	(class process_target): Add the target op.  Also add
	'supports_read_offsets'.
	* target.cc (process_target::read_offsets): Define.
	(process_target::supports_read_offsets): Define.

	Update the derived classes and callers below.

	* server.cc (handle_query): Update.
	* linux-low.cc (SUPPORTS_READ_OFFSETS): New #define directive.
	(linux_target_ops): Update.
	(linux_process_target::supports_read_offsets): Define.
	(linux_read_offsets): Turn into ...
	(linux_process_target::read_offsets): ... this.
	* linux-low.h (class linux_process_target): Update.
	* lynx-low.cc (lynx_target_ops): Update.
	* nto-low.cc (nto_target_ops): Update.
	* win32-low.cc (win32_target_ops): Update.

9 files changed, 75 insertions, 26 deletions

diff --git a/gdbserver/ChangeLog b/gdbserver/ChangeLog
index f7ac9a8..fd2c627 100644
--- a/gdbserver/ChangeLog
+++ b/gdbserver/ChangeLog
@@ -1,5 +1,29 @@
 2020-02-20  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
 
+	Turn process_stratum_target's read_offsets op into a method of
+	process_target.
+
+	* target.h (struct process_stratum_target): Remove the target op.
+	(class process_target): Add the target op.  Also add
+	'supports_read_offsets'.
+	* target.cc (process_target::read_offsets): Define.
+	(process_target::supports_read_offsets): Define.
+
+	Update the derived classes and callers below.
+
+	* server.cc (handle_query): Update.
+	* linux-low.cc (SUPPORTS_READ_OFFSETS): New #define directive.
+	(linux_target_ops): Update.
+	(linux_process_target::supports_read_offsets): Define.
+	(linux_read_offsets): Turn into ...
+	(linux_process_target::read_offsets): ... this.
+	* linux-low.h (class linux_process_target): Update.
+	* lynx-low.cc (lynx_target_ops): Update.
+	* nto-low.cc (nto_target_ops): Update.
+	* win32-low.cc (win32_target_ops): Update.
+
+2020-02-20  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
+
 	Turn process_stratum_target's stopped_by_watchpoint and
 	stopped_data_address ops into methods of process_target.
 
diff --git a/gdbserver/linux-low.cc b/gdbserver/linux-low.cc
index 5a5c637..34bbc0d 100644
--- a/gdbserver/linux-low.cc
+++ b/gdbserver/linux-low.cc
@@ -100,6 +100,14 @@
 #endif
 #endif
 
+#if (defined(__UCLIBC__)		\
+     && defined(HAS_NOMMU)		\
+     && defined(PT_TEXT_ADDR)		\
+     && defined(PT_DATA_ADDR)		\
+     && defined(PT_TEXT_END_ADDR))
+#define SUPPORTS_READ_OFFSETS
+#endif
+
 #ifdef HAVE_LINUX_BTRACE
 # include "nat/linux-btrace.h"
 # include "gdbsupport/btrace-common.h"
@@ -6059,21 +6067,28 @@ linux_process_target::stopped_data_address ()
   return lwp->stopped_data_address;
 }
 
-#if defined(__UCLIBC__) && defined(HAS_NOMMU)	      \
-    && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \
-    && defined(PT_TEXT_END_ADDR)
-
 /* This is only used for targets that define PT_TEXT_ADDR,
    PT_DATA_ADDR and PT_TEXT_END_ADDR.  If those are not defined, supposedly
    the target has different ways of acquiring this information, like
    loadmaps.  */
 
+bool
+linux_process_target::supports_read_offsets ()
+{
+#ifdef SUPPORTS_READ_OFFSETS
+  return true;
+#else
+  return false;
+#endif
+}
+
 /* Under uClinux, programs are loaded at non-zero offsets, which we need
    to tell gdb about.  */
 
-static int
-linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
+int
+linux_process_target::read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
 {
+#ifdef SUPPORTS_READ_OFFSETS
   unsigned long text, text_end, data;
   int pid = lwpid_of (current_thread);
 
@@ -6102,9 +6117,11 @@ linux_read_offsets (CORE_ADDR *text_p, CORE_ADDR *data_p)
 
       return 1;
     }
- return 0;
-}
+  return 0;
+#else
+  gdb_assert_not_reached ("target op read_offsets not supported");
 #endif
+}
 
 static int
 linux_qxfer_osdata (const char *annex,
@@ -7375,13 +7392,6 @@ linux_get_hwcap2 (int wordsize)
 static linux_process_target the_linux_target;
 
 static process_stratum_target linux_target_ops = {
-#if defined(__UCLIBC__) && defined(HAS_NOMMU)	      \
-    && defined(PT_TEXT_ADDR) && defined(PT_DATA_ADDR) \
-    && defined(PT_TEXT_END_ADDR)
-  linux_read_offsets,
-#else
-  NULL,
-#endif
 #ifdef USE_THREAD_DB
   thread_db_get_tls_address,
 #else
diff --git a/gdbserver/linux-low.h b/gdbserver/linux-low.h
index af2a0c6..f2e2dfd 100644
--- a/gdbserver/linux-low.h
+++ b/gdbserver/linux-low.h
@@ -336,6 +336,10 @@ public:
   bool stopped_by_watchpoint () override;
 
   CORE_ADDR stopped_data_address () override;
+
+  bool supports_read_offsets () override;
+
+  int read_offsets (CORE_ADDR *text, CORE_ADDR *data) override;
 };
 
 #define get_thread_lwp(thr) ((struct lwp_info *) (thread_target_data (thr)))
diff --git a/gdbserver/lynx-low.cc b/gdbserver/lynx-low.cc
index e9dfcce..44c57a5 100644
--- a/gdbserver/lynx-low.cc
+++ b/gdbserver/lynx-low.cc
@@ -735,7 +735,6 @@ static lynx_process_target the_lynx_target;
 /* The LynxOS target_ops vector.  */
 
 static process_stratum_target lynx_target_ops = {
-  NULL,  /* read_offsets */
   NULL,  /* get_tls_address */
   NULL,  /* hostio_last_error */
   NULL,  /* qxfer_osdata */
diff --git a/gdbserver/nto-low.cc b/gdbserver/nto-low.cc
index 53020a2..040fa93 100644
--- a/gdbserver/nto-low.cc
+++ b/gdbserver/nto-low.cc
@@ -956,7 +956,6 @@ nto_sw_breakpoint_from_kind (int kind, int *size)
 static nto_process_target the_nto_target;
 
 static process_stratum_target nto_target_ops = {
-  NULL, /* nto_read_offsets */
   NULL, /* thread_db_set_tls_address */
   hostio_last_error_from_errno,
   NULL, /* nto_qxfer_osdata */
diff --git a/gdbserver/server.cc b/gdbserver/server.cc
index f13061c..b4fd9c6 100644
--- a/gdbserver/server.cc
+++ b/gdbserver/server.cc
@@ -2234,13 +2234,13 @@ handle_query (char *own_buf, int packet_len, int *new_packet_len_p)
 	}
     }
 
-  if (the_target->read_offsets != NULL
+  if (the_target->pt->supports_read_offsets ()
       && strcmp ("qOffsets", own_buf) == 0)
     {
       CORE_ADDR text, data;
 
       require_running_or_return (own_buf);
-      if (the_target->read_offsets (&text, &data))
+      if (the_target->pt->read_offsets (&text, &data))
 	sprintf (own_buf, "Text=%lX;Data=%lX;Bss=%lX",
 		 (long)text, (long)data, (long)data);
       else
diff --git a/gdbserver/target.cc b/gdbserver/target.cc
index 00f5f79..501a8d6 100644
--- a/gdbserver/target.cc
+++ b/gdbserver/target.cc
@@ -481,3 +481,15 @@ process_target::stopped_data_address ()
 {
   return 0;
 }
+
+bool
+process_target::supports_read_offsets ()
+{
+  return false;
+}
+
+int
+process_target::read_offsets (CORE_ADDR *text, CORE_ADDR *data)
+{
+  gdb_assert_not_reached ("target op read_offsets not supported");
+}
diff --git a/gdbserver/target.h b/gdbserver/target.h
index 83595fa..5cf039e 100644
--- a/gdbserver/target.h
+++ b/gdbserver/target.h
@@ -70,12 +70,6 @@ class process_target;
    shared code.  */
 struct process_stratum_target
 {
-  /* Reports the text, data offsets of the executable.  This is
-     needed for uclinux where the executable is relocated during load
-     time.  */
-
-  int (*read_offsets) (CORE_ADDR *text, CORE_ADDR *data);
-
   /* Fetch the address associated with a specific thread local storage
      area, determined by the specified THREAD, OFFSET, and LOAD_MODULE.
      Stores it in *ADDRESS and returns zero on success; otherwise returns
@@ -475,6 +469,14 @@ public:
   /* Returns the address associated with the watchpoint that hit, if any;
      returns 0 otherwise.  */
   virtual CORE_ADDR stopped_data_address ();
+
+  /* Return true if the read_offsets target op is supported.  */
+  virtual bool supports_read_offsets ();
+
+  /* Reports the text, data offsets of the executable.  This is
+     needed for uclinux where the executable is relocated during load
+     time.  */
+  virtual int read_offsets (CORE_ADDR *text, CORE_ADDR *data);
 };
 
 extern process_stratum_target *the_target;
diff --git a/gdbserver/win32-low.cc b/gdbserver/win32-low.cc
index ff62bce..875736a 100644
--- a/gdbserver/win32-low.cc
+++ b/gdbserver/win32-low.cc
@@ -1844,7 +1844,6 @@ win32_sw_breakpoint_from_kind (int kind, int *size)
 static win32_process_target the_win32_target;
 
 static process_stratum_target win32_target_ops = {
-  NULL, /* read_offsets */
   NULL, /* get_tls_address */
 #ifdef _WIN32_WCE
   wince_hostio_last_error,