Re: [RFA]: Change to_stopped_data_address ABI

[Jeff Johnston <jjohnstn at redhat dot com>]

The attached patches address your comments below.  Ok now?

-- Jeff J.

Eli Zaretskii wrote:
> > Date: Fri, 24 Sep 2004 18:41:53 -0400
> > From: Jeff Johnston <jjohnstn@redhat.com>
> > Cc: gdb-patches@sources.redhat.com
>
>
> Sorry for a late response.
>
>
> > Andrew/Eli, ok to commit?  Did I miss anything?
>
>
> Thanks, most of the concerns I had with your original patch are now
> gone.  Still, a few minor ones remain, see below.
>
>
> > +int
> > +frv_stopped_data_address (CORE_ADDR *addr_p)
> > {
> >   CORE_ADDR brr, dbar0, dbar1, dbar2, dbar3;
> >
> > @@ -1305,15 +1305,27 @@ frv_stopped_data_address (void)
> >   dbar3 = read_register (dbar3_regnum);
> >
> >   if (brr & (1<<11))
> > -    return dbar0;
> > +    *addr_p = dbar0;
> >   else if (brr & (1<<10))
> > -    return dbar1;
> > +    *addr_p = dbar1;
> >   else if (brr & (1<<9))
> > -    return dbar2;
> > +    *addr_p = dbar2;
> >   else if (brr & (1<<8))
> > -    return dbar3;
> > +    *addr_p = dbar3;
> >   else
> > -    return 0;
> > +    {
> > +      *addr_p = 0;
> > +      return 0;
> > +    }
> > +
> > +  return 1;
> > +}
>
>
> I don't understand why do you put a zero into the address pointed by
> addr_p in the case that no watchpoint has fired.  It is customary to
> leave the arguments unaltered in such cases.  isn't it enough that you
> return a zero as the function's value?
>
> Similar code is in the other functions that return the stopped data
> address; I have similar issue with them.
>
>
> > RCS file: /cvs/src/src/gdb/config/i386/nm-i386.h,v
> > retrieving revision 1.6
> > diff -u -p -r1.6 nm-i386.h
> > --- config/i386/nm-i386.h	13 Sep 2004 14:06:03 -0000	1.6
> > +++ config/i386/nm-i386.h	24 Sep 2004 22:34:27 -0000
> > @@ -47,10 +47,10 @@ extern int i386_region_ok_for_watchpoint
> >    triggered.  */
> > extern int i386_stopped_by_hwbp (void);
> >
> > -/* If the inferior has some break/watchpoint that triggered, return
> > +/* If the inferior has some break/watchpoint that triggered, set
> >    the address associated with that break/watchpoint.  Otherwise,
> > -   return zero.  */
> > -extern CORE_ADDR i386_stopped_data_address (void);
> > +   set the watchpoint address to zero.  Always return true.  */
>
>
> The last sentence is not true: we return zero (false) sometimes.
>
>
> > +@findex i386_stopped_by_watchpoint
> > +@item i386_stopped_by_watchpoint (void)
> > +The macro @code{STOPPED_BY_WATCHPOINT}
> > +is set to call this function.  The
> > +argument passed to @code{STOPPED_BY_WATCHPOINT} is ignored.  This
> > +function uses the same logic as @code{i386_stopped_data_address}.
>
>
> I'd prefer if we describe the operation of i386_stopped_by_watchpoint
> explicitly, not by a reference to the logic of i386_stopped_data_address.
Index: breakpoint.c
===================================================================
RCS file: /cvs/src/src/gdb/breakpoint.c,v
retrieving revision 1.182
diff -u -p -r1.182 breakpoint.c
--- breakpoint.c	13 Sep 2004 18:26:28 -0000	1.182
+++ breakpoint.c	6 Oct 2004 20:46:19 -0000
@@ -2741,8 +2741,7 @@ bpstat_stop_status (CORE_ADDR bp_addr, p
 	struct value *v;
 	int found = 0;
 
-	addr = target_stopped_data_address ();
-	if (addr == 0)
+	if (!target_stopped_data_address (&current_target, &addr))
 	  continue;
 	for (v = b->val_chain; v; v = v->next)
 	  {
Index: frv-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/frv-tdep.c,v
retrieving revision 1.89
diff -u -p -r1.89 frv-tdep.c
--- frv-tdep.c	2 Aug 2004 19:44:39 -0000	1.89
+++ frv-tdep.c	6 Oct 2004 20:46:19 -0000
@@ -1293,8 +1293,8 @@ frv_check_watch_resources (int type, int
 }
 
 
-CORE_ADDR
-frv_stopped_data_address (void)
+int
+frv_stopped_data_address (CORE_ADDR *addr_p)
 {
   CORE_ADDR brr, dbar0, dbar1, dbar2, dbar3;
 
@@ -1305,15 +1305,24 @@ frv_stopped_data_address (void)
   dbar3 = read_register (dbar3_regnum);
 
   if (brr & (1<<11))
-    return dbar0;
+    *addr_p = dbar0;
   else if (brr & (1<<10))
-    return dbar1;
+    *addr_p = dbar1;
   else if (brr & (1<<9))
-    return dbar2;
+    *addr_p = dbar2;
   else if (brr & (1<<8))
-    return dbar3;
+    *addr_p = dbar3;
   else
     return 0;
+
+  return 1;
+}
+
+int
+frv_have_stopped_data_address (void)
+{
+  CORE_ADDR addr = 0;
+  return frv_stopped_data_address (&addr);
 }
 
 static CORE_ADDR
Index: i386-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/i386-nat.c,v
retrieving revision 1.8
diff -u -p -r1.8 i386-nat.c
--- i386-nat.c	5 Mar 2004 20:58:00 -0000	1.8
+++ i386-nat.c	6 Oct 2004 20:46:19 -0000
@@ -564,14 +564,16 @@ i386_region_ok_for_watchpoint (CORE_ADDR
   return nregs <= DR_NADDR ? 1 : 0;
 }
 
-/* If the inferior has some watchpoint that triggered, return the
-   address associated with that watchpoint.  Otherwise, return zero.  */
+/* If the inferior has some watchpoint that triggered, set the
+   address associated with that watchpoint and return non-zero.  
+   Otherwise, return zero.  */
 
-CORE_ADDR
-i386_stopped_data_address (void)
+int
+i386_stopped_data_address (CORE_ADDR *addr_p)
 {
   CORE_ADDR addr = 0;
   int i;
+  int rc = 0;
 
   dr_status_mirror = I386_DR_LOW_GET_STATUS ();
 
@@ -586,6 +588,7 @@ i386_stopped_data_address (void)
 	  && I386_DR_GET_RW_LEN (i) != 0)
 	{
 	  addr = dr_mirror[i];
+	  rc = 1;
 	  if (maint_show_dr)
 	    i386_show_dr ("watchpoint_hit", addr, -1, hw_write);
 	}
@@ -593,7 +596,16 @@ i386_stopped_data_address (void)
   if (maint_show_dr && addr == 0)
     i386_show_dr ("stopped_data_addr", 0, 0, hw_write);
 
-  return addr;
+  if (rc)
+    *addr_p = addr;
+  return rc;
+}
+
+int
+i386_stopped_by_watchpoint (void)
+{
+  CORE_ADDR addr = 0;
+  return i386_stopped_data_address (&addr);
 }
 
 /* Return non-zero if the inferior has some break/watchpoint that
Index: ia64-linux-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/ia64-linux-nat.c,v
retrieving revision 1.24
diff -u -p -r1.24 ia64-linux-nat.c
--- ia64-linux-nat.c	22 Aug 2004 16:32:35 -0000	1.24
+++ ia64-linux-nat.c	6 Oct 2004 20:46:19 -0000
@@ -636,12 +636,13 @@ ia64_linux_remove_watchpoint (ptid_t pti
   return -1;
 }
 
-CORE_ADDR
-ia64_linux_stopped_by_watchpoint (ptid_t ptid)
+int
+ia64_linux_stopped_data_address (CORE_ADDR *addr_p)
 {
   CORE_ADDR psr;
   int tid;
   struct siginfo siginfo;
+  ptid_t ptid = inferior_ptid;
 
   tid = TIDGET(ptid);
   if (tid == 0)
@@ -659,7 +660,15 @@ ia64_linux_stopped_by_watchpoint (ptid_t
                            for the next instruction */
   write_register_pid (IA64_PSR_REGNUM, psr, ptid);
 
-  return (CORE_ADDR) siginfo.si_addr;
+  *addr_p = (CORE_ADDR)siginfo.si_addr;
+  return 1;
+}
+
+int
+ia64_linux_stopped_by_watchpoint (void)
+{
+  CORE_ADDR addr;
+  return ia64_linux_stopped_data_address (&addr);
 }
 
 LONGEST 
Index: remote-m32r-sdi.c
===================================================================
RCS file: /cvs/src/src/gdb/remote-m32r-sdi.c,v
retrieving revision 1.7
diff -u -p -r1.7 remote-m32r-sdi.c
--- remote-m32r-sdi.c	27 Jul 2004 01:00:42 -0000	1.7
+++ remote-m32r-sdi.c	6 Oct 2004 20:46:19 -0000
@@ -1450,16 +1450,23 @@ m32r_remove_watchpoint (CORE_ADDR addr, 
   return 0;
 }
 
-CORE_ADDR
-m32r_stopped_data_address (void)
+int
+m32r_stopped_data_address (struct target_ops *target, CORE_ADDR *addr_p)
 {
-  return hit_watchpoint_addr;
+  int rc = 0;
+  if (hit_watchpoint_addr != 0x00000000)
+    {
+      *addr_p = hit_watchpoint_addr;
+      rc = 1;
+    }
+  return rc;
 }
 
 int
 m32r_stopped_by_watchpoint (void)
 {
-  return (hit_watchpoint_addr != 0x00000000);
+  CORE_ADDR addr;
+  return m32r_stopped_data_address (&current_target, &addr);
 }
 
 
Index: remote.c
===================================================================
RCS file: /cvs/src/src/gdb/remote.c,v
retrieving revision 1.147
diff -u -p -r1.147 remote.c
--- remote.c	13 Sep 2004 18:26:30 -0000	1.147
+++ remote.c	6 Oct 2004 20:46:19 -0000
@@ -4551,13 +4551,18 @@ remote_stopped_by_watchpoint (void)
 
 extern int stepped_after_stopped_by_watchpoint;
 
-static CORE_ADDR
-remote_stopped_data_address (void)
+static int
+remote_stopped_data_address (struct target_ops *target, CORE_ADDR *addr_p)
 {
+  int rc = 0;
   if (remote_stopped_by_watchpoint ()
       || stepped_after_stopped_by_watchpoint)
-    return remote_watch_data_address;
-  return (CORE_ADDR)0;
+    {
+      *addr_p = remote_watch_data_address;
+      rc = 1;
+    }
+
+  return rc;
 }
 
 
Index: target.c
===================================================================
RCS file: /cvs/src/src/gdb/target.c,v
retrieving revision 1.80
diff -u -p -r1.80 target.c
--- target.c	12 Sep 2004 15:20:47 -0000	1.80
+++ target.c	6 Oct 2004 20:46:19 -0000
@@ -127,7 +127,7 @@ static int debug_to_remove_watchpoint (C
 
 static int debug_to_stopped_by_watchpoint (void);
 
-static CORE_ADDR debug_to_stopped_data_address (void);
+static int debug_to_stopped_data_address (struct target_ops *, CORE_ADDR *);
 
 static int debug_to_region_size_ok_for_hw_watchpoint (int);
 
@@ -522,7 +522,7 @@ update_current_target (void)
 	    (int (*) (void))
 	    return_zero);
   de_fault (to_stopped_data_address,
-	    (CORE_ADDR (*) (void))
+	    (int (*) (struct target_ops *, CORE_ADDR *))
 	    return_zero);
   de_fault (to_region_size_ok_for_hw_watchpoint,
 	    default_region_size_ok_for_hw_watchpoint);
@@ -860,6 +860,19 @@ target_write_memory (CORE_ADDR memaddr, 
   return target_xfer_memory (memaddr, myaddr, len, 1);
 }
 
+#ifndef target_stopped_data_address_p
+int
+target_stopped_data_address_p (struct target_ops *target)
+{
+  if (target->to_stopped_data_address == return_zero
+      || (target->to_stopped_data_address == debug_to_stopped_data_address
+	  && debug_target.to_stopped_data_address == return_zero))
+    return 0;
+  else
+    return 1;
+}
+#endif
+
 static int trust_readonly = 0;
 
 /* Move memory to or from the targets.  The top target gets priority;
@@ -1921,16 +1934,17 @@ debug_to_stopped_by_watchpoint (void)
   return retval;
 }
 
-static CORE_ADDR
-debug_to_stopped_data_address (void)
+static int
+debug_to_stopped_data_address (struct target_ops *target, CORE_ADDR *addr)
 {
-  CORE_ADDR retval;
+  int retval;
 
-  retval = debug_target.to_stopped_data_address ();
+  retval = debug_target.to_stopped_data_address (target, addr);
 
   fprintf_unfiltered (gdb_stdlog,
-		      "target_stopped_data_address () = 0x%lx\n",
-		      (unsigned long) retval);
+		      "target_stopped_data_address ([0x%lx]) = %ld\n",
+		      (unsigned long)*addr,
+		      (unsigned long)retval);
   return retval;
 }
 
Index: target.h
===================================================================
RCS file: /cvs/src/src/gdb/target.h,v
retrieving revision 1.60
diff -u -p -r1.60 target.h
--- target.h	7 Jun 2004 17:58:32 -0000	1.60
+++ target.h	6 Oct 2004 20:46:19 -0000
@@ -342,7 +342,7 @@ struct target_ops
     int (*to_insert_watchpoint) (CORE_ADDR, int, int);
     int (*to_stopped_by_watchpoint) (void);
     int to_have_continuable_watchpoint;
-    CORE_ADDR (*to_stopped_data_address) (void);
+    int (*to_stopped_data_address) (struct target_ops *, CORE_ADDR *);
     int (*to_region_size_ok_for_hw_watchpoint) (int);
     void (*to_terminal_init) (void);
     void (*to_terminal_inferior) (void);
@@ -1083,9 +1083,14 @@ extern void (*deprecated_target_new_objf
      (*current_target.to_remove_hw_breakpoint) (addr, save)
 #endif
 
+extern int target_stopped_data_address_p (struct target_ops *);
+
 #ifndef target_stopped_data_address
-#define target_stopped_data_address() \
-    (*current_target.to_stopped_data_address) ()
+#define target_stopped_data_address(target, x) \
+    (*target.to_stopped_data_address) (target, x)
+#else
+/* Horrible hack to get around existing macros :-(.  */
+#define target_stopped_data_address_p(CURRENT_TARGET) (1)
 #endif
 
 /* This will only be defined by a target that supports catching vfork events,
Index: config/i386/nm-i386.h
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/nm-i386.h,v
retrieving revision 1.6
diff -u -p -r1.6 nm-i386.h
--- config/i386/nm-i386.h	13 Sep 2004 14:06:03 -0000	1.6
+++ config/i386/nm-i386.h	6 Oct 2004 20:46:19 -0000
@@ -47,10 +47,10 @@ extern int i386_region_ok_for_watchpoint
    triggered.  */
 extern int i386_stopped_by_hwbp (void);
 
-/* If the inferior has some break/watchpoint that triggered, return
-   the address associated with that break/watchpoint.  Otherwise,
-   return zero.  */
-extern CORE_ADDR i386_stopped_data_address (void);
+/* If the inferior has some break/watchpoint that triggered, set
+   the address associated with that break/watchpoint and return
+   true.  Otherwise, return false.  */
+extern int i386_stopped_data_address (CORE_ADDR *);
 
 /* Insert a hardware-assisted breakpoint at address ADDR.  SHADOW is
    unused.  Return 0 on success, EBUSY on failure.  */
@@ -91,9 +91,11 @@ extern int  i386_remove_hw_breakpoint (C
 
 #define HAVE_CONTINUABLE_WATCHPOINT 1
 
-#define STOPPED_BY_WATCHPOINT(W)       (i386_stopped_data_address () != 0)
+extern int i386_stopped_by_watchpoint (void);
 
-#define target_stopped_data_address()  i386_stopped_data_address ()
+#define STOPPED_BY_WATCHPOINT(W)       (i386_stopped_by_watchpoint () != 0)
+
+#define target_stopped_data_address(target, x)  i386_stopped_data_address(x)
 
 /* Use these macros for watchpoint insertion/removal.  */
 
Index: config/frv/tm-frv.h
===================================================================
RCS file: /cvs/src/src/gdb/config/frv/tm-frv.h,v
retrieving revision 1.6
diff -u -p -r1.6 tm-frv.h
--- config/frv/tm-frv.h	13 Sep 2004 14:06:02 -0000	1.6
+++ config/frv/tm-frv.h	6 Oct 2004 20:46:19 -0000
@@ -1,5 +1,5 @@
 /* Target definitions for the Fujitsu FR-V, for GDB, the GNU Debugger.
-   Copyright 2000 Free Software Foundation, Inc.
+   Copyright 2000, 2004 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -33,10 +33,11 @@ extern int frv_check_watch_resources (in
 #define STOPPED_BY_WATCHPOINT(W) \
    ((W).kind == TARGET_WAITKIND_STOPPED \
    && (W).value.sig == TARGET_SIGNAL_TRAP \
-   && (frv_stopped_data_address() != ((CORE_ADDR)0)))
-extern CORE_ADDR frv_stopped_data_address(void);
+   && frv_have_stopped_data_address())
+extern int frv_have_stopped_data_address(void);
 
 /* Use these macros for watchpoint insertion/deletion.  */
-#define target_stopped_data_address() frv_stopped_data_address()
+#define target_stopped_data_address(target, x) frv_stopped_data_address(x)
+extern int frv_stopped_data_address(CORE_ADDR *addr_p);
 
 #include "solib.h"		/* Include support for shared libraries.  */
Index: config/ia64/nm-linux.h
===================================================================
RCS file: /cvs/src/src/gdb/config/ia64/nm-linux.h,v
retrieving revision 1.15
diff -u -p -r1.15 nm-linux.h
--- config/ia64/nm-linux.h	13 Sep 2004 14:06:03 -0000	1.15
+++ config/ia64/nm-linux.h	6 Oct 2004 20:46:19 -0000
@@ -58,8 +58,12 @@ extern int ia64_cannot_store_register (i
 #define HAVE_STEPPABLE_WATCHPOINT 1
 
 #define STOPPED_BY_WATCHPOINT(W) \
-  ia64_linux_stopped_by_watchpoint (inferior_ptid)
-extern CORE_ADDR ia64_linux_stopped_by_watchpoint (ptid_t ptid);
+  ia64_linux_stopped_by_watchpoint ()
+extern int ia64_linux_stopped_by_watchpoint ();
+
+#define target_stopped_data_address(target, x) \
+  ia64_linux_stopped_data_address(x)
+extern int ia64_linux_stopped_data_address (CORE_ADDR *addr_p);
 
 #define target_insert_watchpoint(addr, len, type) \
   ia64_linux_insert_watchpoint (inferior_ptid, addr, len, type)

Index: gdbint.texinfo
===================================================================
RCS file: /cvs/src/src/gdb/doc/gdbint.texinfo,v
retrieving revision 1.224
diff -u -r1.224 gdbint.texinfo
--- gdbint.texinfo	12 Sep 2004 15:20:49 -0000	1.224
+++ gdbint.texinfo	6 Oct 2004 20:38:14 -0000
@@ -476,9 +476,10 @@
 two macros can use them for their internal purposes.
 
 @findex target_stopped_data_address
-@item target_stopped_data_address ()
-If the inferior has some watchpoint that triggered, return the address
-associated with that watchpoint.  Otherwise, return zero.
+@item target_stopped_data_address (@var{addr_p})
+If the inferior has some watchpoint that triggered, place the address
+associated with the watchpoint at the location pointed to by
+@var{addr_p} and return non-zero.  Otherwise, return zero.
 
 @findex HAVE_STEPPABLE_WATCHPOINT
 @item HAVE_STEPPABLE_WATCHPOINT
@@ -598,15 +599,25 @@
 processors.
 
 @findex i386_stopped_data_address
-@item i386_stopped_data_address (void)
-The macros @code{STOPPED_BY_WATCHPOINT} and
-@code{target_stopped_data_address} are set to call this function.  The
-argument passed to @code{STOPPED_BY_WATCHPOINT} is ignored.  This
+@item i386_stopped_data_address (@var{addr_p})
+The target function
+@code{target_stopped_data_address} is set to call this function.
+This
 function examines the breakpoint condition bits in the DR6 Debug
 Status register, as returned by the @code{I386_DR_LOW_GET_STATUS}
 macro, and returns the address associated with the first bit that is
 set in DR6.
 
+@findex i386_stopped_by_watchpoint
+@item i386_stopped_by_watchpoint (void)
+The macro @code{STOPPED_BY_WATCHPOINT}
+is set to call this function.  The
+argument passed to @code{STOPPED_BY_WATCHPOINT} is ignored.  This
+function examines the breakpoint condition bits in the DR6 Debug
+Status register, as returned by the @code{I386_DR_LOW_GET_STATUS}
+macro, and returns true if any bit is set.  Otherwise, false is
+returned.
+
 @findex i386_insert_watchpoint
 @findex i386_remove_watchpoint
 @item i386_insert_watchpoint (@var{addr}, @var{len}, @var{type})
@@ -654,7 +665,7 @@
 @item i386_stopped_by_hwbp (void)
 This function returns non-zero if the inferior has some watchpoint or
 hardware breakpoint that triggered.  It works like
-@code{i386_stopped_data_address}, except that it doesn't return the
+@code{i386_stopped_data_address}, except that it doesn't record the
 address whose watchpoint triggered.
 
 @findex i386_cleanup_dregs