[1/2] Fix varobj updation after symbol removal
Commit Message
This problem was observed while loading and unloading symbols using
add-symbol-file and remove-symbol-file. When remove-symbol-file
command is invoked, it calls clear_symtab_users that calls varobj_invalidate
to invalidate variable objects. This function invalidates the varobjs
that are tied to locals and re-create the ones that are defined on
globals. During this re-creation of globals, variable objects are
re-evaluated that can result in new value. But this change is not recorded
and because of this, -var-update for such modified variable objects
gives empty change list.
Proposed Fix:
Comments
ping.
-Taimoor
On 06/27/2014 03:13 PM, Taimoor Mirza wrote:
> This problem was observed while loading and unloading symbols using
> add-symbol-file and remove-symbol-file. When remove-symbol-file
> command is invoked, it calls clear_symtab_users that calls varobj_invalidate
> to invalidate variable objects. This function invalidates the varobjs
> that are tied to locals and re-create the ones that are defined on
> globals. During this re-creation of globals, variable objects are
> re-evaluated that can result in new value. But this change is not recorded
> and because of this, -var-update for such modified variable objects
> gives empty change list.
>
> Proposed Fix:
> =============
> GDB has mechanism of marking varobj's updated if they are set via
> varobj_set_value operation. This allows any next -var-update to report
> this change. Same approach should be used during varobj invalidation.
> If value of newly created varobj is different from previous one, mark it
> updated so that -var-update can get this change.
>
> Variable object invalidation code is cleaned up to avoid using pointers
> whose target has been already freed.
>
> Fix Testing:
> ===========
> This fix has been regression tested on both simulator and real boards.
>
> 2014-06-27 Taimoor Mirza <tmirza@codesourcery.com>
> Maciej W. Rozycki <macro@codesourcery.com>
>
> gdb/
> * varobj.h (varobj_is_valid_p, varobj_set_invalid): New
> prototypes.
> * varobj.c (varobj_is_valid_p, varobj_set_invalid): New functions.
> (varobj_invalidate_iter): Mark re-created global object updated
> if its value is different from previous value.
> * objfiles.c (invalidate_objfile_varobj_type_iter): New function.
> (free_objfile): Call it.
>
> ---
> gdb/objfiles.c | 19 +++++++++++++++++++
> gdb/varobj.c | 37 +++++++++++++++++++++++++++++++++++++
> gdb/varobj.h | 3 +++
> 3 files changed, 59 insertions(+)
>
> diff --git a/gdb/objfiles.c b/gdb/objfiles.c
> index 0a0b1cb..03559a3 100644
> --- a/gdb/objfiles.c
> +++ b/gdb/objfiles.c
> @@ -32,6 +32,7 @@
> #include "bcache.h"
> #include "expression.h"
> #include "parser-defs.h"
> +#include "varobj.h"
>
> #include "gdb_assert.h"
> #include <sys/types.h>
> @@ -538,6 +539,21 @@ free_objfile_separate_debug (struct objfile *objfile)
> }
> }
>
> +/* Mark the variable object VAR invalid if built upon a type coming from
> + the objfile requested, passed as DATA. Also clear the type reference. */
> +
> +static void
> +invalidate_objfile_varobj_type_iter (struct varobj *var, void *data)
> +{
> + struct objfile *objfile = data;
> +
> + if (varobj_is_valid_p (var) && TYPE_OBJFILE (var->type) == objfile)
> + {
> + varobj_set_invalid (var);
> + var->type = NULL;
> + }
> +}
> +
> /* Destroy an objfile and all the symtabs and psymtabs under it. */
>
> void
> @@ -584,6 +600,9 @@ free_objfile (struct objfile *objfile)
> lists. */
> preserve_values (objfile);
>
> + /* Varobj may refer to types stored in objfile's obstack. */
> + all_root_varobjs (invalidate_objfile_varobj_type_iter, objfile);
> +
> /* It still may reference data modules have associated with the objfile and
> the symbol file data. */
> forget_cached_source_info_for_objfile (objfile);
> diff --git a/gdb/varobj.c b/gdb/varobj.c
> index 7446f10..2a563af 100644
> --- a/gdb/varobj.c
> +++ b/gdb/varobj.c
> @@ -2683,6 +2683,22 @@ varobj_floating_p (struct varobj *var)
> return var->root->floating;
> }
>
> +/* Get the valid flag of varobj VAR. */
> +
> +int
> +varobj_is_valid_p (struct varobj *var)
> +{
> + return var->root->is_valid;
> +}
> +
> +/* Clear the valid flag on varobj VAR. */
> +
> +void
> +varobj_set_invalid (struct varobj *var)
> +{
> + var->root->is_valid = 0;
> +}
> +
> /* Implement the "value_is_changeable_p" varobj callback for most
> languages. */
>
> @@ -2762,6 +2778,7 @@ varobj_invalidate_iter (struct varobj *var, void *unused)
> if (var->root->floating || var->root->valid_block == NULL)
> {
> struct varobj *tmp_var;
> + char *tmp_var_value, *var_value;
>
> /* Try to create a varobj with same expression. If we succeed
> replace the old varobj, otherwise invalidate it. */
> @@ -2770,6 +2787,26 @@ varobj_invalidate_iter (struct varobj *var, void *unused)
> if (tmp_var != NULL)
> {
> tmp_var->obj_name = xstrdup (var->obj_name);
> + tmp_var_value = varobj_get_value (tmp_var);
> + var_value = varobj_get_value (var);
> +
> + /* As varobjs are re-evaluated during creation so there is a
> + chance that new value is different from old one. Compare
> + value of old varobj and newly created varobj and mark
> + varobj updated If new value is different. */
> + if (var_value == NULL && tmp_var_value == NULL)
> + ; /* Equal. */
> + else if (var_value == NULL || tmp_var_value == NULL)
> + tmp_var->updated = 1;
> + else
> + {
> + /* Mark tmp_var updated if new value is different. */
> + if (strcmp (tmp_var_value, var_value) != 0)
> + tmp_var->updated = 1;
> + }
> +
> + xfree (tmp_var_value);
> + xfree (var_value);
> varobj_delete (var, NULL, 0);
> install_variable (tmp_var);
> }
> diff --git a/gdb/varobj.h b/gdb/varobj.h
> index 74d41cf..7439a94 100644
> --- a/gdb/varobj.h
> +++ b/gdb/varobj.h
> @@ -299,6 +299,9 @@ extern int varobj_editable_p (struct varobj *var);
>
> extern int varobj_floating_p (struct varobj *var);
>
> +extern int varobj_is_valid_p (struct varobj *var);
> +extern void varobj_set_invalid (struct varobj *var);
> +
> extern void varobj_set_visualizer (struct varobj *var,
> const char *visualizer);
>
>
Ping.
On 06/27/2014 03:13 PM, Taimoor Mirza wrote:
> This problem was observed while loading and unloading symbols using
> add-symbol-file and remove-symbol-file. When remove-symbol-file
> command is invoked, it calls clear_symtab_users that calls varobj_invalidate
> to invalidate variable objects. This function invalidates the varobjs
> that are tied to locals and re-create the ones that are defined on
> globals. During this re-creation of globals, variable objects are
> re-evaluated that can result in new value. But this change is not recorded
> and because of this, -var-update for such modified variable objects
> gives empty change list.
>
> Proposed Fix:
> =============
> GDB has mechanism of marking varobj's updated if they are set via
> varobj_set_value operation. This allows any next -var-update to report
> this change. Same approach should be used during varobj invalidation.
> If value of newly created varobj is different from previous one, mark it
> updated so that -var-update can get this change.
>
> Variable object invalidation code is cleaned up to avoid using pointers
> whose target has been already freed.
>
> Fix Testing:
> ===========
> This fix has been regression tested on both simulator and real boards.
>
> 2014-06-27 Taimoor Mirza <tmirza@codesourcery.com>
> Maciej W. Rozycki <macro@codesourcery.com>
>
> gdb/
> * varobj.h (varobj_is_valid_p, varobj_set_invalid): New
> prototypes.
> * varobj.c (varobj_is_valid_p, varobj_set_invalid): New functions.
> (varobj_invalidate_iter): Mark re-created global object updated
> if its value is different from previous value.
> * objfiles.c (invalidate_objfile_varobj_type_iter): New function.
> (free_objfile): Call it.
>
> ---
> gdb/objfiles.c | 19 +++++++++++++++++++
> gdb/varobj.c | 37 +++++++++++++++++++++++++++++++++++++
> gdb/varobj.h | 3 +++
> 3 files changed, 59 insertions(+)
>
> diff --git a/gdb/objfiles.c b/gdb/objfiles.c
> index 0a0b1cb..03559a3 100644
> --- a/gdb/objfiles.c
> +++ b/gdb/objfiles.c
> @@ -32,6 +32,7 @@
> #include "bcache.h"
> #include "expression.h"
> #include "parser-defs.h"
> +#include "varobj.h"
>
> #include "gdb_assert.h"
> #include <sys/types.h>
> @@ -538,6 +539,21 @@ free_objfile_separate_debug (struct objfile *objfile)
> }
> }
>
> +/* Mark the variable object VAR invalid if built upon a type coming from
> + the objfile requested, passed as DATA. Also clear the type reference. */
> +
> +static void
> +invalidate_objfile_varobj_type_iter (struct varobj *var, void *data)
> +{
> + struct objfile *objfile = data;
> +
> + if (varobj_is_valid_p (var) && TYPE_OBJFILE (var->type) == objfile)
> + {
> + varobj_set_invalid (var);
> + var->type = NULL;
> + }
> +}
> +
> /* Destroy an objfile and all the symtabs and psymtabs under it. */
>
> void
> @@ -584,6 +600,9 @@ free_objfile (struct objfile *objfile)
> lists. */
> preserve_values (objfile);
>
> + /* Varobj may refer to types stored in objfile's obstack. */
> + all_root_varobjs (invalidate_objfile_varobj_type_iter, objfile);
> +
> /* It still may reference data modules have associated with the objfile and
> the symbol file data. */
> forget_cached_source_info_for_objfile (objfile);
> diff --git a/gdb/varobj.c b/gdb/varobj.c
> index 7446f10..2a563af 100644
> --- a/gdb/varobj.c
> +++ b/gdb/varobj.c
> @@ -2683,6 +2683,22 @@ varobj_floating_p (struct varobj *var)
> return var->root->floating;
> }
>
> +/* Get the valid flag of varobj VAR. */
> +
> +int
> +varobj_is_valid_p (struct varobj *var)
> +{
> + return var->root->is_valid;
> +}
> +
> +/* Clear the valid flag on varobj VAR. */
> +
> +void
> +varobj_set_invalid (struct varobj *var)
> +{
> + var->root->is_valid = 0;
> +}
> +
> /* Implement the "value_is_changeable_p" varobj callback for most
> languages. */
>
> @@ -2762,6 +2778,7 @@ varobj_invalidate_iter (struct varobj *var, void *unused)
> if (var->root->floating || var->root->valid_block == NULL)
> {
> struct varobj *tmp_var;
> + char *tmp_var_value, *var_value;
>
> /* Try to create a varobj with same expression. If we succeed
> replace the old varobj, otherwise invalidate it. */
> @@ -2770,6 +2787,26 @@ varobj_invalidate_iter (struct varobj *var, void *unused)
> if (tmp_var != NULL)
> {
> tmp_var->obj_name = xstrdup (var->obj_name);
> + tmp_var_value = varobj_get_value (tmp_var);
> + var_value = varobj_get_value (var);
> +
> + /* As varobjs are re-evaluated during creation so there is a
> + chance that new value is different from old one. Compare
> + value of old varobj and newly created varobj and mark
> + varobj updated If new value is different. */
> + if (var_value == NULL && tmp_var_value == NULL)
> + ; /* Equal. */
> + else if (var_value == NULL || tmp_var_value == NULL)
> + tmp_var->updated = 1;
> + else
> + {
> + /* Mark tmp_var updated if new value is different. */
> + if (strcmp (tmp_var_value, var_value) != 0)
> + tmp_var->updated = 1;
> + }
> +
> + xfree (tmp_var_value);
> + xfree (var_value);
> varobj_delete (var, NULL, 0);
> install_variable (tmp_var);
> }
> diff --git a/gdb/varobj.h b/gdb/varobj.h
> index 74d41cf..7439a94 100644
> --- a/gdb/varobj.h
> +++ b/gdb/varobj.h
> @@ -299,6 +299,9 @@ extern int varobj_editable_p (struct varobj *var);
>
> extern int varobj_floating_p (struct varobj *var);
>
> +extern int varobj_is_valid_p (struct varobj *var);
> +extern void varobj_set_invalid (struct varobj *var);
> +
> extern void varobj_set_visualizer (struct varobj *var,
> const char *visualizer);
>
>
Ping
On 08/05/2014 04:00 PM, Taimoor wrote:
>
> Ping.
>
> On 06/27/2014 03:13 PM, Taimoor Mirza wrote:
>> This problem was observed while loading and unloading symbols using
>> add-symbol-file and remove-symbol-file. When remove-symbol-file
>> command is invoked, it calls clear_symtab_users that calls
>> varobj_invalidate
>> to invalidate variable objects. This function invalidates the varobjs
>> that are tied to locals and re-create the ones that are defined on
>> globals. During this re-creation of globals, variable objects are
>> re-evaluated that can result in new value. But this change is not
>> recorded
>> and because of this, -var-update for such modified variable objects
>> gives empty change list.
>>
>> Proposed Fix:
>> =============
>> GDB has mechanism of marking varobj's updated if they are set via
>> varobj_set_value operation. This allows any next -var-update to report
>> this change. Same approach should be used during varobj invalidation.
>> If value of newly created varobj is different from previous one, mark it
>> updated so that -var-update can get this change.
>>
>> Variable object invalidation code is cleaned up to avoid using pointers
>> whose target has been already freed.
>>
>> Fix Testing:
>> ===========
>> This fix has been regression tested on both simulator and real boards.
>>
>> 2014-06-27 Taimoor Mirza <tmirza@codesourcery.com>
>> Maciej W. Rozycki <macro@codesourcery.com>
>>
>> gdb/
>> * varobj.h (varobj_is_valid_p, varobj_set_invalid): New
>> prototypes.
>> * varobj.c (varobj_is_valid_p, varobj_set_invalid): New
>> functions.
>> (varobj_invalidate_iter): Mark re-created global object updated
>> if its value is different from previous value.
>> * objfiles.c (invalidate_objfile_varobj_type_iter): New
>> function.
>> (free_objfile): Call it.
>>
>> ---
>> gdb/objfiles.c | 19 +++++++++++++++++++
>> gdb/varobj.c | 37 +++++++++++++++++++++++++++++++++++++
>> gdb/varobj.h | 3 +++
>> 3 files changed, 59 insertions(+)
>>
>> diff --git a/gdb/objfiles.c b/gdb/objfiles.c
>> index 0a0b1cb..03559a3 100644
>> --- a/gdb/objfiles.c
>> +++ b/gdb/objfiles.c
>> @@ -32,6 +32,7 @@
>> #include "bcache.h"
>> #include "expression.h"
>> #include "parser-defs.h"
>> +#include "varobj.h"
>>
>> #include "gdb_assert.h"
>> #include <sys/types.h>
>> @@ -538,6 +539,21 @@ free_objfile_separate_debug (struct objfile
>> *objfile)
>> }
>> }
>>
>> +/* Mark the variable object VAR invalid if built upon a type coming from
>> + the objfile requested, passed as DATA. Also clear the type
>> reference. */
>> +
>> +static void
>> +invalidate_objfile_varobj_type_iter (struct varobj *var, void *data)
>> +{
>> + struct objfile *objfile = data;
>> +
>> + if (varobj_is_valid_p (var) && TYPE_OBJFILE (var->type) == objfile)
>> + {
>> + varobj_set_invalid (var);
>> + var->type = NULL;
>> + }
>> +}
>> +
>> /* Destroy an objfile and all the symtabs and psymtabs under it. */
>>
>> void
>> @@ -584,6 +600,9 @@ free_objfile (struct objfile *objfile)
>> lists. */
>> preserve_values (objfile);
>>
>> + /* Varobj may refer to types stored in objfile's obstack. */
>> + all_root_varobjs (invalidate_objfile_varobj_type_iter, objfile);
>> +
>> /* It still may reference data modules have associated with the
>> objfile and
>> the symbol file data. */
>> forget_cached_source_info_for_objfile (objfile);
>> diff --git a/gdb/varobj.c b/gdb/varobj.c
>> index 7446f10..2a563af 100644
>> --- a/gdb/varobj.c
>> +++ b/gdb/varobj.c
>> @@ -2683,6 +2683,22 @@ varobj_floating_p (struct varobj *var)
>> return var->root->floating;
>> }
>>
>> +/* Get the valid flag of varobj VAR. */
>> +
>> +int
>> +varobj_is_valid_p (struct varobj *var)
>> +{
>> + return var->root->is_valid;
>> +}
>> +
>> +/* Clear the valid flag on varobj VAR. */
>> +
>> +void
>> +varobj_set_invalid (struct varobj *var)
>> +{
>> + var->root->is_valid = 0;
>> +}
>> +
>> /* Implement the "value_is_changeable_p" varobj callback for most
>> languages. */
>>
>> @@ -2762,6 +2778,7 @@ varobj_invalidate_iter (struct varobj *var, void
>> *unused)
>> if (var->root->floating || var->root->valid_block == NULL)
>> {
>> struct varobj *tmp_var;
>> + char *tmp_var_value, *var_value;
>>
>> /* Try to create a varobj with same expression. If we succeed
>> replace the old varobj, otherwise invalidate it. */
>> @@ -2770,6 +2787,26 @@ varobj_invalidate_iter (struct varobj *var,
>> void *unused)
>> if (tmp_var != NULL)
>> {
>> tmp_var->obj_name = xstrdup (var->obj_name);
>> + tmp_var_value = varobj_get_value (tmp_var);
>> + var_value = varobj_get_value (var);
>> +
>> + /* As varobjs are re-evaluated during creation so there is a
>> + chance that new value is different from old one. Compare
>> + value of old varobj and newly created varobj and mark
>> + varobj updated If new value is different. */
>> + if (var_value == NULL && tmp_var_value == NULL)
>> + ; /* Equal. */
>> + else if (var_value == NULL || tmp_var_value == NULL)
>> + tmp_var->updated = 1;
>> + else
>> + {
>> + /* Mark tmp_var updated if new value is different. */
>> + if (strcmp (tmp_var_value, var_value) != 0)
>> + tmp_var->updated = 1;
>> + }
>> +
>> + xfree (tmp_var_value);
>> + xfree (var_value);
>> varobj_delete (var, NULL, 0);
>> install_variable (tmp_var);
>> }
>> diff --git a/gdb/varobj.h b/gdb/varobj.h
>> index 74d41cf..7439a94 100644
>> --- a/gdb/varobj.h
>> +++ b/gdb/varobj.h
>> @@ -299,6 +299,9 @@ extern int varobj_editable_p (struct varobj *var);
>>
>> extern int varobj_floating_p (struct varobj *var);
>>
>> +extern int varobj_is_valid_p (struct varobj *var);
>> +extern void varobj_set_invalid (struct varobj *var);
>> +
>> extern void varobj_set_visualizer (struct varobj *var,
>> const char *visualizer);
>>
>>
=============
GDB has mechanism of marking varobj's updated if they are set via
varobj_set_value operation. This allows any next -var-update to report
this change. Same approach should be used during varobj invalidation.
If value of newly created varobj is different from previous one, mark it
updated so that -var-update can get this change.
Variable object invalidation code is cleaned up to avoid using pointers
whose target has been already freed.
Fix Testing:
===========
This fix has been regression tested on both simulator and real boards.
2014-06-27 Taimoor Mirza <tmirza@codesourcery.com>
Maciej W. Rozycki <macro@codesourcery.com>
gdb/
* varobj.h (varobj_is_valid_p, varobj_set_invalid): New
prototypes.
* varobj.c (varobj_is_valid_p, varobj_set_invalid): New functions.
(varobj_invalidate_iter): Mark re-created global object updated
if its value is different from previous value.
* objfiles.c (invalidate_objfile_varobj_type_iter): New function.
(free_objfile): Call it.
---
gdb/objfiles.c | 19 +++++++++++++++++++
gdb/varobj.c | 37 +++++++++++++++++++++++++++++++++++++
gdb/varobj.h | 3 +++
3 files changed, 59 insertions(+)
@@ -32,6 +32,7 @@
#include "bcache.h"
#include "expression.h"
#include "parser-defs.h"
+#include "varobj.h"
#include "gdb_assert.h"
#include <sys/types.h>
@@ -538,6 +539,21 @@ free_objfile_separate_debug (struct objfile *objfile)
}
}
+/* Mark the variable object VAR invalid if built upon a type coming from
+ the objfile requested, passed as DATA. Also clear the type reference. */
+
+static void
+invalidate_objfile_varobj_type_iter (struct varobj *var, void *data)
+{
+ struct objfile *objfile = data;
+
+ if (varobj_is_valid_p (var) && TYPE_OBJFILE (var->type) == objfile)
+ {
+ varobj_set_invalid (var);
+ var->type = NULL;
+ }
+}
+
/* Destroy an objfile and all the symtabs and psymtabs under it. */
void
@@ -584,6 +600,9 @@ free_objfile (struct objfile *objfile)
lists. */
preserve_values (objfile);
+ /* Varobj may refer to types stored in objfile's obstack. */
+ all_root_varobjs (invalidate_objfile_varobj_type_iter, objfile);
+
/* It still may reference data modules have associated with the objfile and
the symbol file data. */
forget_cached_source_info_for_objfile (objfile);
@@ -2683,6 +2683,22 @@ varobj_floating_p (struct varobj *var)
return var->root->floating;
}
+/* Get the valid flag of varobj VAR. */
+
+int
+varobj_is_valid_p (struct varobj *var)
+{
+ return var->root->is_valid;
+}
+
+/* Clear the valid flag on varobj VAR. */
+
+void
+varobj_set_invalid (struct varobj *var)
+{
+ var->root->is_valid = 0;
+}
+
/* Implement the "value_is_changeable_p" varobj callback for most
languages. */
@@ -2762,6 +2778,7 @@ varobj_invalidate_iter (struct varobj *var, void *unused)
if (var->root->floating || var->root->valid_block == NULL)
{
struct varobj *tmp_var;
+ char *tmp_var_value, *var_value;
/* Try to create a varobj with same expression. If we succeed
replace the old varobj, otherwise invalidate it. */
@@ -2770,6 +2787,26 @@ varobj_invalidate_iter (struct varobj *var, void *unused)
if (tmp_var != NULL)
{
tmp_var->obj_name = xstrdup (var->obj_name);
+ tmp_var_value = varobj_get_value (tmp_var);
+ var_value = varobj_get_value (var);
+
+ /* As varobjs are re-evaluated during creation so there is a
+ chance that new value is different from old one. Compare
+ value of old varobj and newly created varobj and mark
+ varobj updated If new value is different. */
+ if (var_value == NULL && tmp_var_value == NULL)
+ ; /* Equal. */
+ else if (var_value == NULL || tmp_var_value == NULL)
+ tmp_var->updated = 1;
+ else
+ {
+ /* Mark tmp_var updated if new value is different. */
+ if (strcmp (tmp_var_value, var_value) != 0)
+ tmp_var->updated = 1;
+ }
+
+ xfree (tmp_var_value);
+ xfree (var_value);
varobj_delete (var, NULL, 0);
install_variable (tmp_var);
}
@@ -299,6 +299,9 @@ extern int varobj_editable_p (struct varobj *var);
extern int varobj_floating_p (struct varobj *var);
+extern int varobj_is_valid_p (struct varobj *var);
+extern void varobj_set_invalid (struct varobj *var);
+
extern void varobj_set_visualizer (struct varobj *var,
const char *visualizer);