Class readonly_detached_regcache

This patch adds a new class (type) for readonly regcache, which is
created via regcache::save.  readonly_detached_regcache inherits
readable_regcache.

gdb:

2018-02-21  Yao Qi  <yao.qi@linaro.org>

	* dummy-frame.c (dummy_frame_cache) <prev_regcache>: Use
	readonly_detached_regcache.
	(dummy_frame_prev_register): Use regcache->cooked_read.
	* frame.c (frame_save_as_regcache): Change return type.
	(frame_pop): Update.
	* frame.h (frame_save_as_regcache): Update declaration.
	* inferior.h (get_infcall_suspend_state_regcache): Update
	declaration.
	* infrun.c (infcall_suspend_state) <registers>: use
	readonly_detached_regcache.
	(save_infcall_suspend_state): Don't use regcache_dup.
	(get_infcall_suspend_state_regcache): Change return type.
	* linux-fork.c (struct fork_info) <savedregs>: Change to
	readonly_detached_regcache.
	<pc>: New field.
	(fork_save_infrun_state): Don't use regcache_dup.
	(info_checkpoints_command): Adjust.
	* mi/mi-main.c (register_changed_p): Update declaration.
	(mi_cmd_data_list_changed_registers): Use
	readonly_detached_regcache.
	(register_changed_p): Change parameter type to
	readonly_detached_regcache.
	* ppc-linux-tdep.c (ppu2spu_cache) <regcache>: Use
	readonly_detached_regcache.
	(ppu2spu_sniffer): Construct a new readonly_detached_regcache.
	* regcache.c (readonly_detached_regcache::readonly_detached_regcache):
	New.
	(regcache::save): Move it to reg_buffer.
	(regcache::restore): Change parameter type.
	(regcache_dup): Remove.
	* regcache.h (reg_buffer) <save>: New method.
	(readonly_detached_regcache): New class.
	* spu-tdep.c (spu2ppu_cache) <regcache>: Use
	readonly_detached_regcache.
	(spu2ppu_sniffer): Construct a new readonly_detached_regcache.

1 files changed, 8 insertions, 10 deletions

diff --git a/gdb/linux-fork.c b/gdb/linux-fork.c
index df7ea4e..9ffab1f 100644
--- a/gdb/linux-fork.c
+++ b/gdb/linux-fork.c
@@ -45,8 +45,9 @@ struct fork_info
   ptid_t ptid;
   ptid_t parent_ptid;
   int num;			/* Convenient handle (GDB fork id).  */
-  struct regcache *savedregs;	/* Convenient for info fork, saves
+  readonly_detached_regcache *savedregs;	/* Convenient for info fork, saves
 				   having to actually switch contexts.  */
+  CORE_ADDR pc;
   int clobber_regs;		/* True if we should restore saved regs.  */
   off_t *filepos;		/* Set of open file descriptors' offsets.  */
   int maxfd;
@@ -294,7 +295,8 @@ fork_save_infrun_state (struct fork_info *fp, int clobber_regs)
   if (fp->savedregs)
     delete fp->savedregs;
 
-  fp->savedregs = regcache_dup (get_current_regcache ());
+  fp->savedregs = new readonly_detached_regcache (*get_current_regcache ());
+  fp->pc = regcache_read_pc (get_current_regcache ());
   fp->clobber_regs = clobber_regs;
 
   if (clobber_regs)
@@ -590,15 +592,11 @@ info_checkpoints_command (const char *arg, int from_tty)
 
       printed = fp;
       if (ptid_equal (fp->ptid, inferior_ptid))
-	{
-	  printf_filtered ("* ");
-	  pc = regcache_read_pc (get_current_regcache ());
-	}
+	printf_filtered ("* ");
       else
-	{
-	  printf_filtered ("  ");
-	  pc = regcache_read_pc (fp->savedregs);
-	}
+	printf_filtered ("  ");
+
+      pc = fp->pc;
       printf_filtered ("%d %s", fp->num, target_pid_to_str (fp->ptid));
       if (fp->num == 0)
 	printf_filtered (_(" (main process)"));