From patchwork Thu Apr 16 03:32:39 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Taimoor Mirza X-Patchwork-Id: 6249 Received: (qmail 66469 invoked by alias); 16 Apr 2015 03:33:29 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 66459 invoked by uid 89); 16 Apr 2015 03:33:29 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.1 required=5.0 tests=AWL, BAYES_00, RCVD_IN_DNSWL_LOW, SPF_PASS autolearn=ham version=3.3.2 X-HELO: relay1.mentorg.com Received: from relay1.mentorg.com (HELO relay1.mentorg.com) (192.94.38.131) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 16 Apr 2015 03:33:27 +0000 Received: from nat-ies.mentorg.com ([192.94.31.2] helo=SVR-IES-FEM-01.mgc.mentorg.com) by relay1.mentorg.com with esmtp id 1YiaYO-0003iT-NB from Taimoor_Mirza@mentor.com for gdb-patches@sourceware.org; Wed, 15 Apr 2015 20:33:24 -0700 Received: from PKL-TAIMOORMI-LT.mgc.mentorg.com (137.202.0.76) by SVR-IES-FEM-01.mgc.mentorg.com (137.202.0.104) with Microsoft SMTP Server (TLS) id 14.3.224.2; Thu, 16 Apr 2015 04:32:58 +0100 From: Taimoor Mirza To: CC: Taimoor Mirza Subject: [PATCH 1/2] Fix varobj updation after symbol removal Date: Thu, 16 Apr 2015 08:32:39 +0500 Message-ID: <1429155160-4816-2-git-send-email-tmirza@codesourcery.com> In-Reply-To: <1429155160-4816-1-git-send-email-tmirza@codesourcery.com> References: <1429155160-4816-1-git-send-email-tmirza@codesourcery.com> MIME-Version: 1.0 X-IsSubscribed: yes 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. 2015-04-15 Taimoor Mirza Maciej W. Rozycki 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. Signed-off-by: Taimoor Mirza --- 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 ff20bc8..5905998 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 #include @@ -533,6 +534,21 @@ 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 @@ -579,6 +595,9 @@ 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 b220fd8..4860a37 100644 --- a/gdb/varobj.c +++ b/gdb/varobj.c @@ -2699,6 +2699,22 @@ varobj_floating_p (const 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. */ @@ -2760,6 +2776,7 @@ 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. */ @@ -2768,6 +2785,26 @@ 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 8860526..4afb9e8 100644 --- a/gdb/varobj.h +++ b/gdb/varobj.h @@ -311,6 +311,9 @@ extern int varobj_editable_p (const struct varobj *var); extern int varobj_floating_p (const 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);