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Re: [RFC] varobj deletion after the binary has changed
- From: Denis PILAT <denis dot pilat at st dot com>
- To: Nick Roberts <nickrob at snap dot net dot nz>
- Cc: Eli Zaretskii <eliz at gnu dot org>, drow at false dot org, gdb-patches at sourceware dot org
- Date: Mon, 12 Feb 2007 13:19:07 +0100
- Subject: Re: [RFC] varobj deletion after the binary has changed
- References: <20070123124457.GA1600@nevyn.them.org> <45B63A49.4010609@st.com> <45B8E8A8.9040904@st.com> <17849.12231.246980.478169@kahikatea.snap.net.nz> <20070125232731.GA30178@nevyn.them.org> <45BDEAEC.1050006@st.com> <17854.28971.170898.231523@kahikatea.snap.net.nz> <45C0B042.9040308@st.com> <17857.2617.164646.935952@kahikatea.snap.net.nz> <45C1B78C.60605@st.com> <20070208164103.GA13544@nevyn.them.org> <17867.31476.627368.180759@kahikatea.snap.net.nz> <uy7n79w0k.fsf@gnu.org>
Nick,
Thanks you for the documentation update.
Hereby is 2 patches I would like to commit, the C part and the new . exp
file.
I change the .exp file with your comment, with a newer copyright notice,
and with including value field in output of -var-create.
I also changed a comment plus typos in the C code.
Daniel already approved the sources, Eli is near to be fine with the doc.
Could have a look once more into the following, at least for the
ChangeLog entry ?
Then how could we synchronize our commit ?
--
Denis
ChangeLog for the testsuite:
2007-02-12 Denis Pilat <denis.pilat@st.com>
* gdb.mi/mi-var-invalidate.exp: New files.
2007-02-12 Denis Pilat <denis.pilat@st.com>
* varobj.c (struct varobj_root): Add is_valid member.
(varobj_get_type): Check for invalid varobj.
(varobj_get_attributes): Likewise.
(variable_editable):Likewise.
(varobj_update): Likewise plus use an enum for returned error values.
(new_root_variable): Set root varobj as valid by default.
(varobj_invalidate): New function.
* varobj.h (enum varobj_update_error): New enum.
(varobj_invalidate): New function.
* symfile.c (clear_symtab_users): Use varobj_invalidate.
* mi/mi-cmd-var.c (varobj_update_one): Change returned type to void and
use of new enum varobj_update_error to deal with errors.
Index: symfile.c
===================================================================
RCS file: /cvs/src/src/gdb/symfile.c,v
retrieving revision 1.180
diff -u -p -r1.180 symfile.c
--- symfile.c 21 Jan 2007 01:02:03 -0000 1.180
+++ symfile.c 12 Feb 2007 09:54:22 -0000
@@ -52,6 +52,7 @@
#include "observer.h"
#include "exec.h"
#include "parser-defs.h"
+#include "varobj.h"
#include <sys/types.h>
#include <fcntl.h>
@@ -2602,6 +2603,10 @@ clear_symtab_users (void)
between expressions and which ought to be reset each time. */
expression_context_block = NULL;
innermost_block = NULL;
+
+ /* Varobj may refer to old symbols, perform a cleanup. */
+ varobj_invalidate ();
+
}
static void
Index: varobj.c
===================================================================
RCS file: /cvs/src/src/gdb/varobj.c,v
retrieving revision 1.83
diff -u -p -r1.83 varobj.c
--- varobj.c 8 Feb 2007 17:39:48 -0000 1.83
+++ varobj.c 12 Feb 2007 09:54:30 -0000
@@ -71,6 +71,10 @@ struct varobj_root
using the currently selected frame. */
int use_selected_frame;
+ /* Flag that indicates validity: set to 0 when this varobj_root refers
+ to symbols that do not exist anymore. */
+ int is_valid;
+
/* Language info for this variable and its children */
struct language_specific *lang;
@@ -742,8 +746,9 @@ varobj_get_type (struct varobj *var)
long length;
/* For the "fake" variables, do not return a type. (It's type is
- NULL, too.) */
- if (CPLUS_FAKE_CHILD (var))
+ NULL, too.)
+ Do not return a type for invalid variables as well. */
+ if (CPLUS_FAKE_CHILD (var) || !var->root->is_valid)
return NULL;
stb = mem_fileopen ();
@@ -778,7 +783,7 @@ varobj_get_attributes (struct varobj *va
{
int attributes = 0;
- if (variable_editable (var))
+ if (var->root->is_valid && variable_editable (var))
/* FIXME: define masks for attributes */
attributes |= 0x00000001; /* Editable */
@@ -1018,16 +1023,15 @@ install_new_value (struct varobj *var, s
expression to see if it's changed. Then go all the way
through its children, reconstructing them and noting if they've
changed.
- Return value:
- -1 if there was an error updating the varobj
- -2 if the type changed
- Otherwise it is the number of children + parent changed
+ Return value:
+ < 0 for error values, see varobj.h.
+ Otherwise it is the number of children + parent changed.
Only root variables can be updated...
NOTE: This function may delete the caller's varobj. If it
- returns -2, then it has done this and VARP will be modified
- to point to the new varobj. */
+ returns TYPE_CHANGED, then it has done this and VARP will be modified
+ to point to the new varobj. */
int
varobj_update (struct varobj **varp, struct varobj ***changelist)
@@ -1046,34 +1050,37 @@ varobj_update (struct varobj **varp, str
struct frame_id old_fid;
struct frame_info *fi;
- /* sanity check: have we been passed a pointer? */
+ /* sanity check: have we been passed a pointer? */
if (changelist == NULL)
- return -1;
+ return WRONG_PARAM;
- /* Only root variables can be updated... */
+ /* Only root variables can be updated... */
if (!is_root_p (*varp))
- /* Not a root var */
- return -1;
+ /* Not a root var. */
+ return WRONG_PARAM;
+
+ if (!(*varp)->root->is_valid)
+ return INVALID;
/* Save the selected stack frame, since we will need to change it
- in order to evaluate expressions. */
+ in order to evaluate expressions. */
old_fid = get_frame_id (deprecated_selected_frame);
/* Update the root variable. value_of_root can return NULL
if the variable is no longer around, i.e. we stepped out of
the frame in which a local existed. We are letting the
value_of_root variable dispose of the varobj if the type
- has changed. */
+ has changed. */
type_changed = 1;
new = value_of_root (varp, &type_changed);
- /* Restore selected frame */
+ /* Restore selected frame. */
fi = frame_find_by_id (old_fid);
if (fi)
select_frame (fi);
/* If this is a "use_selected_frame" varobj, and its type has changed,
- them note that it's changed. */
+ them note that it's changed. */
if (type_changed)
VEC_safe_push (varobj_p, result, *varp);
@@ -1090,12 +1097,12 @@ varobj_update (struct varobj **varp, str
/* This means the varobj itself is out of scope.
Report it. */
VEC_free (varobj_p, result);
- return -1;
+ return NOT_IN_SCOPE;
}
VEC_safe_push (varobj_p, stack, *varp);
- /* Walk through the children, reconstructing them all. */
+ /* Walk through the children, reconstructing them all. */
while (!VEC_empty (varobj_p, stack))
{
v = VEC_pop (varobj_p, stack);
@@ -1126,7 +1133,7 @@ varobj_update (struct varobj **varp, str
}
}
- /* Alloc (changed + 1) list entries */
+ /* Alloc (changed + 1) list entries. */
changed = VEC_length (varobj_p, result);
*changelist = xmalloc ((changed + 1) * sizeof (struct varobj *));
cv = *changelist;
@@ -1140,7 +1147,7 @@ varobj_update (struct varobj **varp, str
*cv = 0;
if (type_changed)
- return -2;
+ return TYPE_CHANGED;
else
return changed;
}
@@ -1409,6 +1416,7 @@ new_root_variable (void)
var->root->frame = null_frame_id;
var->root->use_selected_frame = 0;
var->root->rootvar = NULL;
+ var->root->is_valid = 1;
return var;
}
@@ -1692,7 +1700,10 @@ variable_editable (struct varobj *var)
static char *
my_value_of_variable (struct varobj *var)
{
- return (*var->root->lang->value_of_variable) (var);
+ if (var->root->is_valid)
+ return (*var->root->lang->value_of_variable) (var);
+ else
+ return NULL;
}
static char *
@@ -2504,3 +2515,44 @@ When non-zero, varobj debugging is enabl
show_varobjdebug,
&setlist, &showlist);
}
+
+/* Invalidate the varobjs that are tied to locals and re-create the ones that
+ are defined on globals.
+ Invalidated varobjs will be always printed in_scope="invalid". */
+void
+varobj_invalidate (void)
+{
+ struct varobj **all_rootvarobj;
+ struct varobj **varp;
+
+ if (varobj_list (&all_rootvarobj) > 0)
+ {
+ varp = all_rootvarobj;
+ while (*varp != NULL)
+ {
+ /* global var must be re-evaluated. */
+ if ((*varp)->root->valid_block == NULL)
+ {
+ struct varobj *tmp_var;
+
+ /* Try to create a varobj with same expression. If we succeed replace
+ the old varobj, otherwise invalidate it. */
+ tmp_var = varobj_create (NULL, (*varp)->name, (CORE_ADDR) 0, USE_CURRENT_FRAME);
+ if (tmp_var != NULL)
+ {
+ tmp_var->obj_name = xstrdup ((*varp)->obj_name);
+ varobj_delete (*varp, NULL, 0);
+ install_variable (tmp_var);
+ }
+ else
+ (*varp)->root->is_valid = 0;
+ }
+ else /* locals must be invalidated. */
+ (*varp)->root->is_valid = 0;
+
+ varp++;
+ }
+ xfree (all_rootvarobj);
+ }
+ return;
+}
Index: varobj.h
===================================================================
RCS file: /cvs/src/src/gdb/varobj.h,v
retrieving revision 1.7
diff -u -p -r1.7 varobj.h
--- varobj.h 9 Jan 2007 17:58:59 -0000 1.7
+++ varobj.h 12 Feb 2007 09:54:33 -0000
@@ -38,7 +38,16 @@ enum varobj_type
USE_CURRENT_FRAME, /* Use the current frame */
USE_SELECTED_FRAME /* Always reevaluate in selected frame */
};
-
+
+/* Error return values for varobj_update function. */
+enum varobj_update_error
+ {
+ NOT_IN_SCOPE = -1, /* varobj not in scope, can not be updated. */
+ TYPE_CHANGED = -2, /* varobj type has changed. */
+ INVALID = -3, /* varobj is not valid anymore. */
+ WRONG_PARAM = -4 /* function is called with wrong arguments. */
+ };
+
/* String representations of gdb's format codes (defined in varobj.c) */
extern char *varobj_format_string[];
@@ -99,4 +108,6 @@ extern int varobj_list (struct varobj **
extern int varobj_update (struct varobj **varp, struct varobj ***changelist);
+extern void varobj_invalidate (void);
+
#endif /* VAROBJ_H */
Index: mi/mi-cmd-var.c
===================================================================
RCS file: /cvs/src/src/gdb/mi/mi-cmd-var.c,v
retrieving revision 1.29
diff -u -p -r1.29 mi-cmd-var.c
--- mi/mi-cmd-var.c 8 Feb 2007 19:46:30 -0000 1.29
+++ mi/mi-cmd-var.c 12 Feb 2007 09:54:33 -0000
@@ -34,9 +34,9 @@ const char mi_no_values[] = "--no-values
const char mi_simple_values[] = "--simple-values";
const char mi_all_values[] = "--all-values";
-extern int varobjdebug; /* defined in varobj.c */
+extern int varobjdebug; /* defined in varobj.c. */
-static int varobj_update_one (struct varobj *var,
+static void varobj_update_one (struct varobj *var,
enum print_values print_values);
static int mi_print_value_p (struct type *type, enum print_values print_values);
@@ -535,11 +535,9 @@ mi_cmd_var_update (char *command, char *
return MI_CMD_DONE;
}
-/* Helper for mi_cmd_var_update() Returns 0 if the update for
- the variable fails (usually because the variable is out of
- scope), and 1 if it succeeds. */
+/* Helper for mi_cmd_var_update(). */
-static int
+static void
varobj_update_one (struct varobj *var, enum print_values print_values)
{
struct varobj **changelist;
@@ -549,37 +547,39 @@ varobj_update_one (struct varobj *var, e
nc = varobj_update (&var, &changelist);
- /* nc == 0 means that nothing has changed.
- nc == -1 means that an error occured in updating the variable.
- nc == -2 means the variable has changed type. */
+ /* nc >= 0 represents the number of changes reported into changelist.
+ nc < 0 means that an error occured or the the variable has
+ changed type (TYPE_CHANGED). */
if (nc == 0)
- return 1;
- else if (nc == -1)
+ return;
+ else if (nc < 0)
{
if (mi_version (uiout) > 1)
cleanup = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
ui_out_field_string (uiout, "name", varobj_get_objname(var));
- ui_out_field_string (uiout, "in_scope", "false");
- if (mi_version (uiout) > 1)
- do_cleanups (cleanup);
- return -1;
- }
- else if (nc == -2)
- {
- if (mi_version (uiout) > 1)
- cleanup = make_cleanup_ui_out_tuple_begin_end (uiout, NULL);
- ui_out_field_string (uiout, "name", varobj_get_objname (var));
- ui_out_field_string (uiout, "in_scope", "true");
- ui_out_field_string (uiout, "new_type", varobj_get_type(var));
- ui_out_field_int (uiout, "new_num_children",
- varobj_get_num_children(var));
+
+ switch (nc)
+ {
+ case NOT_IN_SCOPE:
+ case WRONG_PARAM:
+ ui_out_field_string (uiout, "in_scope", "false");
+ break;
+ case INVALID:
+ ui_out_field_string (uiout, "in_scope", "invalid");
+ break;
+ case TYPE_CHANGED:
+ ui_out_field_string (uiout, "in_scope", "true");
+ ui_out_field_string (uiout, "new_type", varobj_get_type(var));
+ ui_out_field_int (uiout, "new_num_children",
+ varobj_get_num_children(var));
+ break;
+ }
if (mi_version (uiout) > 1)
do_cleanups (cleanup);
}
else
{
-
cc = changelist;
while (*cc != NULL)
{
@@ -595,7 +595,5 @@ varobj_update_one (struct varobj *var, e
cc++;
}
xfree (changelist);
- return 1;
}
- return 1;
}
# Copyright 2007 Free Software Foundation, Inc.
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#
# Test essential Machine interface (MI) operations
#
# Verify that once binary file has changed, GDB correctly handles
# previously defined MI variables.
#
load_lib mi-support.exp
set MIFLAGS "-i=mi"
gdb_exit
if [mi_gdb_start] {
continue
}
set testfile "var-cmd"
set srcfile ${testfile}.c
set binfile ${objdir}/${subdir}/${testfile}
if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug additional_flags=-DFAKEARGV}] != "" } {
untested mi-var-invalidate.exp
return -1
}
# Just change the output binary.
set binfile_bis ${objdir}/${subdir}/${testfile}_bis
if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile_bis}" executable {debug additional_flags=-DFAKEARGV}] != "" } {
untested mi-var-invalidate.exp
return -1
}
set testfile2 "basics"
set srcfile2 ${testfile2}.c
set binfile2 ${objdir}/${subdir}/${testfile2}
if { [gdb_compile "${srcdir}/${subdir}/${srcfile2}" "${binfile2}" executable {debug additional_flags=-DFAKEARGV}] != "" } {
untested mi-var-invalidate.exp
return -1
}
mi_delete_breakpoints
mi_gdb_reinitialize_dir $srcdir/$subdir
mi_gdb_load ${binfile}
# Desc: Create global variable.
mi_gdb_test "-var-create global_simple * global_simple" \
"\\^done,name=\"global_simple\",numchild=\"6\",value=\".*\",type=\"simpleton\"" \
"create global variable"
mi_runto do_locals_tests
# Desc: create local variables
mi_gdb_test "-var-create linteger * linteger" \
"\\^done,name=\"linteger\",numchild=\"0\",value=\".*\",type=\"int\"" \
"create local variable linteger"
#
# Reload the same binary.
# Global variable should remain, local should be invalidated.
#
mi_delete_breakpoints
mi_gdb_load ${binfile_bis}
mi_runto main
# Check local variable is "invalid".
mi_gdb_test "-var-update linteger" \
"\\^done,changelist=\\\[\{name=\"linteger\",in_scope=\"invalid\"\}\\\]" \
"linteger not anymore in scope due to binary changes"
mi_gdb_test "-var-info-type linteger" \
"\\^done,type=\"\"" \
"no type for invalid variable linteger (1)"
# Check global variable is still correct.
mi_gdb_test "-var-update global_simple" \
"\\^done,changelist=\\\[\]" \
"global_simple still alive"
mi_gdb_test "-var-info-type global_simple" \
"\\^done,type=\"simpleton\"" \
"type simpleton for valid variable global_simple"
#
# Load an other binary.
# All variables must be invalidated.
#
mi_delete_breakpoints
mi_gdb_load ${binfile2}
# Check local variable are "invalid"
mi_gdb_test "-var-update linteger" \
"\\^done,changelist=\\\[\{name=\"linteger\",in_scope=\"invalid\"\}\\\]" \
"linteger not valid anymore due to binary changes"
mi_gdb_test "-var-info-type linteger" \
"\\^done,type=\"\"" \
"no type for invalid variable linteger (2)"
# Check global variable are still correct.
mi_gdb_test "-var-update global_simple" \
"\\^done,changelist=\\\[\{name=\"global_simple\",in_scope=\"invalid\"\}\\\]" \
"global_simple not anymore in scope due to binary changes"
mi_gdb_test "-var-info-type global_simple" \
"\\^done,type=\"\"" \
"no type for invalid variable global_simple"
mi_gdb_exit
return 0