2009-01-01 Pedro Alves <pedro@codesourcery.com>

PR breakpoints/9681:
	* exceptions.h (enum errors): New error type, MEMORY_ERROR.
	* corefile.c (memory_error): Rewrite to throw a MEMORY_ERROR.
	* breakpoint.c (fetch_watchpoint_value): Ignore MEMORY_ERRORs, but
	retrow all other exceptions.

2009-01-01  Pedro Alves  <pedro@codesourcery.com>

	PR breakpoints/9681:
	* gdb.base/watchpoint.exp: Add regression test.

gdb/ChangeLog

@@ -1,3 +1,11 @@
+2009-01-01  Pedro Alves  <pedro@codesourcery.com>
+
+	PR breakpoints/9681:
+	* exceptions.h (enum errors): New error type, MEMORY_ERROR.
+	* corefile.c (memory_error): Rewrite to throw a MEMORY_ERROR.
+	* breakpoint.c (fetch_watchpoint_value): Ignore MEMORY_ERRORs, but
+	retrow all other exceptions.
+
 2008-12-31  Pedro Alves  <pedro@codesourcery.com>
 
 	PR gdb/8812:

gdb/breakpoint.c

@@ -755,7 +755,7 @@ is_hardware_watchpoint (struct breakpoint *bpt)
    in *VAL_CHAIN.  RESULTP and VAL_CHAIN may be NULL if the caller does
    not need them.
 
-   If an error occurs while evaluating the expression, *RESULTP will
+   If a memory error occurs while evaluating the expression, *RESULTP will
    be set to NULL.  *RESULTP may be a lazy value, if the result could
    not be read from memory.  It is used to determine whether a value
    is user-specified (we should watch the whole value) or intermediate
@@ -776,6 +776,7 @@ fetch_watchpoint_value (struct expression *exp, struct value **valp,
 			struct value **resultp, struct value **val_chain)
 {
   struct value *mark, *new_mark, *result;
+  volatile struct gdb_exception ex;
 
   *valp = NULL;
   if (resultp)
@@ -786,7 +787,26 @@ fetch_watchpoint_value (struct expression *exp, struct value **valp,
   /* Evaluate the expression.  */
   mark = value_mark ();
   result = NULL;
-  gdb_evaluate_expression (exp, &result);
+
+  TRY_CATCH (ex, RETURN_MASK_ALL)
+    {
+      result = evaluate_expression (exp);
+    }
+  if (ex.reason < 0)
+    {
+      /* Ignore memory errors, we want watchpoints pointing at
+	 inaccessible memory to still be created; otherwise, throw the
+	 error to some higher catcher.  */
+      switch (ex.error)
+	{
+	case MEMORY_ERROR:
+	  break;
+	default:
+	  throw_exception (ex);
+	  break;
+	}
+    }
+
   new_mark = value_mark ();
   if (mark == new_mark)
     return;

gdb/corefile.c

@@ -205,30 +205,22 @@ Use the \"file\" or \"exec-file\" command."));
 }
 
 
-/* Report a memory error with error().  */
+/* Report a memory error by throwing a MEMORY_ERROR error.  */
 
 void
 memory_error (int status, CORE_ADDR memaddr)
 {
-  struct ui_file *tmp_stream = mem_fileopen ();
-  make_cleanup_ui_file_delete (tmp_stream);
-
   if (status == EIO)
-    {
+    /* Actually, address between memaddr and memaddr + len was out of
-      /* Actually, address between memaddr and memaddr + len
+       bounds.  */
-         was out of bounds. */
+    throw_error (MEMORY_ERROR,
-      fprintf_unfiltered (tmp_stream, "Cannot access memory at address ");
+		 _("Cannot access memory at address %s"),
-      fputs_filtered (paddress (memaddr), tmp_stream);
+		 paddress (memaddr));
-    }
   else
-    {
+    throw_error (MEMORY_ERROR,
-      fprintf_filtered (tmp_stream, "Error accessing memory address ");
+		 _("Error accessing memory address %s: %s."),
-      fputs_filtered (paddress (memaddr), tmp_stream);
+		 paddress (memaddr),
-      fprintf_filtered (tmp_stream, ": %s.",
 		 safe_strerror (status));
-    }
-
-  error_stream (tmp_stream);
 }
 
 /* Same as target_read_memory, but report an error if can't read.  */

gdb/exceptions.h

@@ -72,6 +72,9 @@ enum errors {
   /* Problem parsing an XML document.  */
   XML_PARSE_ERROR,
 
+  /* Error accessing memory.  */
+  MEMORY_ERROR,
+
   /* Add more errors here.  */
   NR_ERRORS
 };

gdb/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2009-01-01  Pedro Alves  <pedro@codesourcery.com>
+
+	PR breakpoints/9681:
+	* gdb.base/watchpoint.exp: Add regression test.
+
 2008-12-31  Pedro Alves  <pedro@codesourcery.com>
 
 	* gdb.threads/attach-into-signal.exp: Don't use

gdb/testsuite/gdb.base/watchpoint.exp

@@ -649,6 +649,18 @@ proc test_inaccessible_watchpoint {} {
     # valid) memory.
 
     if [runto func4] then {
+	# Make sure we only allow memory access errors.
+	set msg "watchpoint refused to insert on nonexistent struct member"
+	gdb_test_multiple "watch struct1.nosuchmember" $msg {
+	    -re ".*atchpoint \[0-9\]+: struct1.nosuchmember.*$gdb_prompt $" {
+		# PR breakpoints/9681
+		fail $msg
+	    }
+	    -re "There is no member named nosuchmember\\..*$gdb_prompt $" {
+		pass $msg
+	    }
+	}
+
 	gdb_test "watch *global_ptr" ".*atchpoint \[0-9\]+: \\*global_ptr"
 	gdb_test "next" ".*global_ptr = buf.*"
 	gdb_test_multiple "next" "next over ptr init" {