[RFC] Add support of software single step to process record

Hui Zhu teawater@gmail.com
Fri Dec 18 08:21:00 GMT 2009


Hi guys,

This patch to make prec support software single step.
I just try it with i386.  Shuchang, please help me try it on mips.  :)

BTW, There are still some other patches for record_resume and
record_wait. And other arch patch is still not begin to be review.  So
this patch is not very urgency.  It just help the guys that are
working on prec arch porting.

Thanks,
Hui

2009-12-18  Hui Zhu  <teawater@gmail.com>

	* breakpoint.c (inserted_single_step_breakpoint_p): New
	function.
	* breakpoint.h (inserted_single_step_breakpoint_p): Extern.
	* record.c (record_resume): Add code for software single step.
	(record_wait): Ditto.

---
 breakpoint.c |   12 ++++++++++++
 breakpoint.h |    1 +
 record.c     |   35 ++++++++++++++++++++++++++++++-----
 3 files changed, 43 insertions(+), 5 deletions(-)

--- a/breakpoint.c
+++ b/breakpoint.c
@@ -9624,6 +9624,18 @@ insert_single_step_breakpoint (struct gd
 	     paddress (gdbarch, next_pc));
 }

+/* Check if the breakpoints used for software single stepping
inserted or not.  */
+
+int
+inserted_single_step_breakpoint_p (void)
+{
+  if (single_step_breakpoints[0] != NULL
+      || single_step_breakpoints[1] != NULL)
+    return 1;
+
+  return 1;
+}
+
 /* Remove and delete any breakpoints used for software single step.  */

 void
--- a/breakpoint.h
+++ b/breakpoint.h
@@ -944,6 +944,7 @@ extern int remove_hw_watchpoints (void);
    twice before remove is called.  */
 extern void insert_single_step_breakpoint (struct gdbarch *,
 					   struct address_space *, CORE_ADDR);
+extern int inserted_single_step_breakpoint_p (void);
 extern void remove_single_step_breakpoints (void);

 /* Manage manual breakpoints, separate from the normal chain of
--- a/record.c
+++ b/record.c
@@ -995,6 +995,8 @@ record_resume (struct target_ops *ops, p

   if (!RECORD_IS_REPLAY)
     {
+      struct gdbarch *gdbarch = get_current_arch ();
+
       if (do_record_message (get_current_regcache (), signal))
         {
           record_resume_error = 0;
@@ -1004,8 +1006,18 @@ record_resume (struct target_ops *ops, p
           record_resume_error = 1;
           return;
         }
-      record_beneath_to_resume (record_beneath_to_resume_ops, ptid, 1,
-                                signal);
+
+      if (gdbarch_software_single_step_p (gdbarch))
+        {
+          if (!inserted_single_step_breakpoint_p ())
+            gdbarch_software_single_step (gdbarch, get_current_frame ());
+          record_beneath_to_resume (record_beneath_to_resume_ops,
+                                    ptid, step, signal);
+          record_resume_step = 0;
+        }
+      else
+        record_beneath_to_resume (record_beneath_to_resume_ops, ptid, 1,
+                                  signal);
     }
 }

@@ -1086,6 +1098,7 @@ record_wait (struct target_ops *ops,
 	  /* This is not a single step.  */
 	  ptid_t ret;
 	  CORE_ADDR tmp_pc;
+          struct gdbarch *gdbarch = get_current_arch ();

 	  while (1)
 	    {
@@ -1108,6 +1121,9 @@ record_wait (struct target_ops *ops,
 		  tmp_pc = regcache_read_pc (regcache);
 		  aspace = get_regcache_aspace (regcache);

+                  if (gdbarch_software_single_step_p (gdbarch))
+                    remove_single_step_breakpoints ();
+
 		  if (target_stopped_by_watchpoint ())
 		    {
 		      /* Always interested in watchpoints.  */
@@ -1133,9 +1149,18 @@ record_wait (struct target_ops *ops,
 		      if (!do_record_message (regcache, TARGET_SIGNAL_0))
 			break;

-		      record_beneath_to_resume (record_beneath_to_resume_ops,
-						ptid, 1,
-						TARGET_SIGNAL_0);
+                      if (gdbarch_software_single_step_p (gdbarch))
+                        {
+                          gdbarch_software_single_step (gdbarch,
+                                                        get_current_frame ());
+                          record_beneath_to_resume
(record_beneath_to_resume_ops,
+                                                    ptid, 0,
+                                                    TARGET_SIGNAL_0);
+                        }
+                      else
+		        record_beneath_to_resume (record_beneath_to_resume_ops,
+						  ptid, 1,
+						  TARGET_SIGNAL_0);
 		      continue;
 		    }
 		}
-------------- next part --------------
---
 breakpoint.c |   12 ++++++++++++
 breakpoint.h |    1 +
 record.c     |   35 ++++++++++++++++++++++++++++++-----
 3 files changed, 43 insertions(+), 5 deletions(-)

--- a/breakpoint.c
+++ b/breakpoint.c
@@ -9624,6 +9624,18 @@ insert_single_step_breakpoint (struct gd
 	     paddress (gdbarch, next_pc));
 }
 
+/* Check if the breakpoints used for software single stepping inserted or not.  */
+
+int
+inserted_single_step_breakpoint_p (void)
+{
+  if (single_step_breakpoints[0] != NULL
+      || single_step_breakpoints[1] != NULL)
+    return 1;
+
+  return 1;
+}
+
 /* Remove and delete any breakpoints used for software single step.  */
 
 void
--- a/breakpoint.h
+++ b/breakpoint.h
@@ -944,6 +944,7 @@ extern int remove_hw_watchpoints (void);
    twice before remove is called.  */
 extern void insert_single_step_breakpoint (struct gdbarch *,
 					   struct address_space *, CORE_ADDR);
+extern int inserted_single_step_breakpoint_p (void);
 extern void remove_single_step_breakpoints (void);
 
 /* Manage manual breakpoints, separate from the normal chain of
--- a/record.c
+++ b/record.c
@@ -995,6 +995,8 @@ record_resume (struct target_ops *ops, p
 
   if (!RECORD_IS_REPLAY)
     {
+      struct gdbarch *gdbarch = get_current_arch ();
+
       if (do_record_message (get_current_regcache (), signal))
         {
           record_resume_error = 0;
@@ -1004,8 +1006,18 @@ record_resume (struct target_ops *ops, p
           record_resume_error = 1;
           return;
         }
-      record_beneath_to_resume (record_beneath_to_resume_ops, ptid, 1,
-                                signal);
+
+      if (gdbarch_software_single_step_p (gdbarch))
+        {
+          if (!inserted_single_step_breakpoint_p ())
+            gdbarch_software_single_step (gdbarch, get_current_frame ());
+          record_beneath_to_resume (record_beneath_to_resume_ops,
+                                    ptid, step, signal);
+          record_resume_step = 0;
+        }
+      else
+        record_beneath_to_resume (record_beneath_to_resume_ops, ptid, 1,
+                                  signal);
     }
 }
 
@@ -1086,6 +1098,7 @@ record_wait (struct target_ops *ops,
 	  /* This is not a single step.  */
 	  ptid_t ret;
 	  CORE_ADDR tmp_pc;
+          struct gdbarch *gdbarch = get_current_arch ();
 
 	  while (1)
 	    {
@@ -1108,6 +1121,9 @@ record_wait (struct target_ops *ops,
 		  tmp_pc = regcache_read_pc (regcache);
 		  aspace = get_regcache_aspace (regcache);
 
+                  if (gdbarch_software_single_step_p (gdbarch))
+                    remove_single_step_breakpoints ();
+
 		  if (target_stopped_by_watchpoint ())
 		    {
 		      /* Always interested in watchpoints.  */
@@ -1133,9 +1149,18 @@ record_wait (struct target_ops *ops,
 		      if (!do_record_message (regcache, TARGET_SIGNAL_0))
 			break;
 
-		      record_beneath_to_resume (record_beneath_to_resume_ops,
-						ptid, 1,
-						TARGET_SIGNAL_0);
+                      if (gdbarch_software_single_step_p (gdbarch))
+                        {
+                          gdbarch_software_single_step (gdbarch,
+                                                        get_current_frame ());
+                          record_beneath_to_resume (record_beneath_to_resume_ops,
+                                                    ptid, 0,
+                                                    TARGET_SIGNAL_0);
+                        }
+                      else
+		        record_beneath_to_resume (record_beneath_to_resume_ops,
+						  ptid, 1,
+						  TARGET_SIGNAL_0);
 		      continue;
 		    }
 		}


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