From 238b7404b66983c6ba15c3a44bfbf642f20bdabe Mon Sep 17 00:00:00 2001
From: Philippe Proulx <eeppeliteloop@gmail.com>
Date: Fri, 30 Nov 2018 15:51:42 -0500
Subject: [PATCH] lib: trace IR, values: reset pointers to `NULL` on
 destruction

When an object's member is destroyed, internally, reset its pointer
to `NULL` immediately. This makes it possible to log partial objects
during destruction while keeping Valgrind's memcheck happy.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
---
 lib/trace-ir/attributes.c    |  2 +-
 lib/trace-ir/clock-class.c   |  4 ++++
 lib/trace-ir/clock-value.c   |  2 +-
 lib/trace-ir/event-class.c   |  6 ++++--
 lib/trace-ir/event.c         |  7 ++++++-
 lib/trace-ir/field-classes.c | 18 ++++++++++++------
 lib/trace-ir/field-path.c    |  1 +
 lib/trace-ir/field-wrapper.c |  1 +
 lib/trace-ir/fields.c        |  6 +++++-
 lib/trace-ir/packet.c        |  8 +++++++-
 lib/trace-ir/stream-class.c  | 11 +++++++----
 lib/trace-ir/stream.c        |  2 ++
 lib/trace-ir/trace.c         |  8 ++++++++
 lib/values.c                 |  3 +++
 14 files changed, 62 insertions(+), 17 deletions(-)

diff --git a/lib/trace-ir/attributes.c b/lib/trace-ir/attributes.c
index 68c83f5f..44068de2 100644
--- a/lib/trace-ir/attributes.c
+++ b/lib/trace-ir/attributes.c
@@ -71,7 +71,7 @@ BT_HIDDEN
 void bt_attributes_destroy(struct bt_private_value *attr_obj)
 {
 	BT_LOGD("Destroying attributes object: addr=%p", attr_obj);
-	bt_object_put_ref(attr_obj);
+	BT_OBJECT_PUT_REF_AND_RESET(attr_obj);
 }
 
 BT_HIDDEN
diff --git a/lib/trace-ir/clock-class.c b/lib/trace-ir/clock-class.c
index d268ec3f..4cfd01c8 100644
--- a/lib/trace-ir/clock-class.c
+++ b/lib/trace-ir/clock-class.c
@@ -50,10 +50,14 @@ void destroy_clock_class(struct bt_object *obj)
 
 	if (clock_class->name.str) {
 		g_string_free(clock_class->name.str, TRUE);
+		clock_class->name.str = NULL;
+		clock_class->name.value = NULL;
 	}
 
 	if (clock_class->description.str) {
 		g_string_free(clock_class->description.str, TRUE);
+		clock_class->description.str = NULL;
+		clock_class->description.value = NULL;
 	}
 
 	bt_object_pool_finalize(&clock_class->cv_pool);
diff --git a/lib/trace-ir/clock-value.c b/lib/trace-ir/clock-value.c
index 877d8687..affc565c 100644
--- a/lib/trace-ir/clock-value.c
+++ b/lib/trace-ir/clock-value.c
@@ -39,7 +39,7 @@ BT_HIDDEN
 void bt_clock_value_destroy(struct bt_clock_value *clock_value)
 {
 	BT_LIB_LOGD("Destroying clock value: %!+k", clock_value);
-	bt_object_put_ref(clock_value->clock_class);
+	BT_OBJECT_PUT_REF_AND_RESET(clock_value->clock_class);
 	g_free(clock_value);
 }
 
diff --git a/lib/trace-ir/event-class.c b/lib/trace-ir/event-class.c
index 15397ff6..685c09c3 100644
--- a/lib/trace-ir/event-class.c
+++ b/lib/trace-ir/event-class.c
@@ -63,16 +63,18 @@ void destroy_event_class(struct bt_object *obj)
 
 	if (event_class->name.str) {
 		g_string_free(event_class->name.str, TRUE);
+		event_class->name.str = NULL;
 	}
 
 	if (event_class->emf_uri.str) {
 		g_string_free(event_class->emf_uri.str, TRUE);
+		event_class->emf_uri.str = NULL;
 	}
 
 	BT_LOGD_STR("Putting context field classe.");
-	bt_object_put_ref(event_class->specific_context_fc);
+	BT_OBJECT_PUT_REF_AND_RESET(event_class->specific_context_fc);
 	BT_LOGD_STR("Putting payload field classe.");
-	bt_object_put_ref(event_class->payload_fc);
+	BT_OBJECT_PUT_REF_AND_RESET(event_class->payload_fc);
 	bt_object_pool_finalize(&event_class->event_pool);
 	g_free(obj);
 }
diff --git a/lib/trace-ir/event.c b/lib/trace-ir/event.c
index dc88ab5c..7d31a401 100644
--- a/lib/trace-ir/event.c
+++ b/lib/trace-ir/event.c
@@ -283,21 +283,25 @@ void bt_event_destroy(struct bt_event *event)
 	if (event->header_field) {
 		BT_LOGD_STR("Releasing event's header field.");
 		release_event_header_field(event->header_field, event);
+		event->header_field = NULL;
 	}
 
 	if (event->common_context_field) {
 		BT_LOGD_STR("Destroying event's stream event context field.");
 		bt_field_destroy(event->common_context_field);
+		event->common_context_field = NULL;
 	}
 
 	if (event->specific_context_field) {
 		BT_LOGD_STR("Destroying event's context field.");
 		bt_field_destroy(event->specific_context_field);
+		event->specific_context_field = NULL;
 	}
 
 	if (event->payload_field) {
 		BT_LOGD_STR("Destroying event's payload field.");
 		bt_field_destroy(event->payload_field);
+		event->payload_field = NULL;
 	}
 
 	BT_LOGD_STR("Putting event's class.");
@@ -305,10 +309,11 @@ void bt_event_destroy(struct bt_event *event)
 
 	if (event->default_cv) {
 		bt_clock_value_recycle(event->default_cv);
+		event->default_cv = NULL;
 	}
 
 	BT_LOGD_STR("Putting event's packet.");
-	bt_object_put_ref(event->packet);
+	BT_OBJECT_PUT_REF_AND_RESET(event->packet);
 	g_free(event);
 }
 
diff --git a/lib/trace-ir/field-classes.c b/lib/trace-ir/field-classes.c
index 485482f8..2adf0348 100644
--- a/lib/trace-ir/field-classes.c
+++ b/lib/trace-ir/field-classes.c
@@ -216,10 +216,12 @@ void destroy_enumeration_field_class(struct bt_object *obj)
 		}
 
 		g_array_free(fc->mappings, TRUE);
+		fc->mappings = NULL;
 	}
 
 	if (fc->label_buf) {
 		g_ptr_array_free(fc->label_buf, TRUE);
+		fc->label_buf = NULL;
 	}
 
 	g_free(fc);
@@ -668,7 +670,7 @@ void finalize_named_field_class(struct bt_named_field_class *named_fc)
 	}
 
 	BT_LOGD_STR("Putting named field class's field class.");
-	bt_object_put_ref(named_fc->fc);
+	BT_OBJECT_PUT_REF_AND_RESET(named_fc->fc);
 }
 
 static
@@ -876,7 +878,9 @@ void destroy_variant_field_class(struct bt_object *obj)
 	BT_LIB_LOGD("Destroying variant field class object: %!+F", fc);
 	finalize_named_field_classes_container((void *) fc);
 	BT_LOGD_STR("Putting selector field path.");
-	bt_object_put_ref(fc->selector_field_path);
+	BT_OBJECT_PUT_REF_AND_RESET(fc->selector_field_path);
+	BT_LOGD_STR("Putting selector field class.");
+	BT_OBJECT_PUT_REF_AND_RESET(fc->selector_fc);
 	g_free(fc);
 }
 
@@ -920,7 +924,7 @@ int bt_private_field_class_variant_set_selector_field_class(
 	BT_ASSERT_PRE_FC_HAS_ID(fc, BT_FIELD_CLASS_TYPE_VARIANT, "Field class");
 	BT_ASSERT_PRE_FC_IS_ENUM(selector_fc, "Selector field class");
 	BT_ASSERT_PRE_FC_HOT(fc, "Variant field class");
-	var_fc->selector_fc = (void *) selector_fc;
+	var_fc->selector_fc = bt_object_get_ref(selector_fc);
 	bt_field_class_freeze((void *) selector_fc);
 	return 0;
 }
@@ -1008,7 +1012,7 @@ void finalize_array_field_class(struct bt_field_class_array *array_fc)
 {
 	BT_ASSERT(array_fc);
 	BT_LOGD_STR("Putting element field class.");
-	bt_object_put_ref(array_fc->element_fc);
+	BT_OBJECT_PUT_REF_AND_RESET(array_fc->element_fc);
 }
 
 static
@@ -1086,7 +1090,9 @@ void destroy_dynamic_array_field_class(struct bt_object *obj)
 	BT_LIB_LOGD("Destroying dynamic array field class object: %!+F", fc);
 	finalize_array_field_class((void *) fc);
 	BT_LOGD_STR("Putting length field path.");
-	bt_object_put_ref(fc->length_field_path);
+	BT_OBJECT_PUT_REF_AND_RESET(fc->length_field_path);
+	BT_LOGD_STR("Putting length field class.");
+	BT_OBJECT_PUT_REF_AND_RESET(fc->length_fc);
 	g_free(fc);
 }
 
@@ -1130,7 +1136,7 @@ int bt_private_field_class_dynamic_array_set_length_field_class(
 		"Field class");
 	BT_ASSERT_PRE_FC_IS_UNSIGNED_INT(length_fc, "Length field class");
 	BT_ASSERT_PRE_FC_HOT(fc, "Dynamic array field class");
-	array_fc->length_fc = length_fc;
+	array_fc->length_fc = bt_object_get_ref(length_fc);
 	bt_field_class_freeze(length_fc);
 	return 0;
 }
diff --git a/lib/trace-ir/field-path.c b/lib/trace-ir/field-path.c
index 613974e6..48a03a86 100644
--- a/lib/trace-ir/field-path.c
+++ b/lib/trace-ir/field-path.c
@@ -44,6 +44,7 @@ void destroy_field_path(struct bt_object *obj)
 	BT_ASSERT(field_path);
 	BT_LIB_LOGD("Destroying field path: %!+P", field_path);
 	g_array_free(field_path->indexes, TRUE);
+	field_path->indexes = NULL;
 	g_free(field_path);
 }
 
diff --git a/lib/trace-ir/field-wrapper.c b/lib/trace-ir/field-wrapper.c
index ed50537a..08cd11e6 100644
--- a/lib/trace-ir/field-wrapper.c
+++ b/lib/trace-ir/field-wrapper.c
@@ -58,6 +58,7 @@ void bt_field_wrapper_destroy(struct bt_field_wrapper *field_wrapper)
 	if (field_wrapper->field) {
 		BT_LOGD_STR("Destroying field.");
 		bt_field_destroy((void *) field_wrapper->field);
+		field_wrapper->field = NULL;
 	}
 
 	BT_LOGD_STR("Putting stream class.");
diff --git a/lib/trace-ir/fields.c b/lib/trace-ir/fields.c
index 91e85099..8eadc757 100644
--- a/lib/trace-ir/fields.c
+++ b/lib/trace-ir/fields.c
@@ -871,7 +871,7 @@ void bt_field_finalize(struct bt_field *field)
 {
 	BT_ASSERT(field);
 	BT_LOGD_STR("Putting field's class.");
-	bt_object_put_ref(field->class);
+	BT_OBJECT_PUT_REF_AND_RESET(field->class);
 }
 
 static
@@ -903,6 +903,7 @@ void destroy_structure_field(struct bt_field *field)
 
 	if (struct_field->fields) {
 		g_ptr_array_free(struct_field->fields, TRUE);
+		struct_field->fields = NULL;
 	}
 
 	g_free(field);
@@ -919,6 +920,7 @@ void destroy_variant_field(struct bt_field *field)
 
 	if (var_field->fields) {
 		g_ptr_array_free(var_field->fields, TRUE);
+		var_field->fields = NULL;
 	}
 
 	g_free(field);
@@ -935,6 +937,7 @@ void destroy_array_field(struct bt_field *field)
 
 	if (array_field->fields) {
 		g_ptr_array_free(array_field->fields, TRUE);
+		array_field->fields = NULL;
 	}
 
 	g_free(field);
@@ -951,6 +954,7 @@ void destroy_string_field(struct bt_field *field)
 
 	if (string_field->buf) {
 		g_array_free(string_field->buf, TRUE);
+		string_field->buf = NULL;
 	}
 
 	g_free(field);
diff --git a/lib/trace-ir/packet.c b/lib/trace-ir/packet.c
index 44a06fb0..983887c4 100644
--- a/lib/trace-ir/packet.c
+++ b/lib/trace-ir/packet.c
@@ -218,6 +218,8 @@ void bt_packet_destroy(struct bt_packet *packet)
 		} else {
 			bt_field_wrapper_destroy(packet->header_field);
 		}
+
+		packet->header_field = NULL;
 	}
 
 	if (packet->context_field) {
@@ -228,20 +230,24 @@ void bt_packet_destroy(struct bt_packet *packet)
 		} else {
 			bt_field_wrapper_destroy(packet->context_field);
 		}
+
+		packet->context_field = NULL;
 	}
 
 	if (packet->default_beginning_cv) {
 		BT_LOGD_STR("Recycling beginning clock value.");
 		bt_clock_value_recycle(packet->default_beginning_cv);
+		packet->default_beginning_cv = NULL;
 	}
 
 	if (packet->default_end_cv) {
 		BT_LOGD_STR("Recycling end clock value.");
 		bt_clock_value_recycle(packet->default_end_cv);
+		packet->default_end_cv = NULL;
 	}
 
 	BT_LOGD_STR("Putting packet's stream.");
-	bt_object_put_ref(packet->stream);
+	BT_OBJECT_PUT_REF_AND_RESET(packet->stream);
 	g_free(packet);
 }
 
diff --git a/lib/trace-ir/stream-class.c b/lib/trace-ir/stream-class.c
index d3e1e90e..9d016844 100644
--- a/lib/trace-ir/stream-class.c
+++ b/lib/trace-ir/stream-class.c
@@ -56,23 +56,26 @@ void destroy_stream_class(struct bt_object *obj)
 
 	BT_LIB_LOGD("Destroying stream class: %!+S", stream_class);
 	BT_LOGD_STR("Putting default clock class.");
-	bt_object_put_ref(stream_class->default_clock_class);
+	BT_OBJECT_PUT_REF_AND_RESET(stream_class->default_clock_class);
 
 	if (stream_class->event_classes) {
 		BT_LOGD_STR("Destroying event classes.");
 		g_ptr_array_free(stream_class->event_classes, TRUE);
+		stream_class->event_classes = NULL;
 	}
 
 	if (stream_class->name.str) {
 		g_string_free(stream_class->name.str, TRUE);
+		stream_class->name.str = NULL;
+		stream_class->name.value = NULL;
 	}
 
 	BT_LOGD_STR("Putting event header field classe.");
-	bt_object_put_ref(stream_class->event_header_fc);
+	BT_OBJECT_PUT_REF_AND_RESET(stream_class->event_header_fc);
 	BT_LOGD_STR("Putting packet context field classe.");
-	bt_object_put_ref(stream_class->packet_context_fc);
+	BT_OBJECT_PUT_REF_AND_RESET(stream_class->packet_context_fc);
 	BT_LOGD_STR("Putting event common context field classe.");
-	bt_object_put_ref(stream_class->event_common_context_fc);
+	BT_OBJECT_PUT_REF_AND_RESET(stream_class->event_common_context_fc);
 	bt_object_pool_finalize(&stream_class->event_header_field_pool);
 	bt_object_pool_finalize(&stream_class->packet_context_field_pool);
 	g_free(stream_class);
diff --git a/lib/trace-ir/stream.c b/lib/trace-ir/stream.c
index 5bf37b52..c90728da 100644
--- a/lib/trace-ir/stream.c
+++ b/lib/trace-ir/stream.c
@@ -54,6 +54,8 @@ void destroy_stream(struct bt_object *obj)
 
 	if (stream->name.str) {
 		g_string_free(stream->name.str, TRUE);
+		stream->name.str = NULL;
+		stream->name.value = NULL;
 	}
 
 	bt_object_pool_finalize(&stream->packet_pool);
diff --git a/lib/trace-ir/trace.c b/lib/trace-ir/trace.c
index b57f2dcc..f5c66cb8 100644
--- a/lib/trace-ir/trace.c
+++ b/lib/trace-ir/trace.c
@@ -89,6 +89,7 @@ void destroy_trace(struct bt_object *obj)
 		}
 
 		g_array_free(trace->is_static_listeners, TRUE);
+		trace->is_static_listeners = NULL;
 	}
 
 	bt_object_pool_finalize(&trace->packet_header_field_pool);
@@ -96,28 +97,35 @@ void destroy_trace(struct bt_object *obj)
 	if (trace->environment) {
 		BT_LOGD_STR("Destroying environment attributes.");
 		bt_attributes_destroy(trace->environment);
+		trace->environment = NULL;
 	}
 
 	if (trace->name.str) {
 		g_string_free(trace->name.str, TRUE);
+		trace->name.str = NULL;
+		trace->name.value = NULL;
 	}
 
 	if (trace->streams) {
 		BT_LOGD_STR("Destroying streams.");
 		g_ptr_array_free(trace->streams, TRUE);
+		trace->streams = NULL;
 	}
 
 	if (trace->stream_classes) {
 		BT_LOGD_STR("Destroying stream classes.");
 		g_ptr_array_free(trace->stream_classes, TRUE);
+		trace->stream_classes = NULL;
 	}
 
 	if (trace->stream_classes_stream_count) {
 		g_hash_table_destroy(trace->stream_classes_stream_count);
+		trace->stream_classes_stream_count = NULL;
 	}
 
 	BT_LOGD_STR("Putting packet header field classe.");
 	bt_object_put_ref(trace->packet_header_fc);
+	trace->packet_header_fc = NULL;
 	g_free(trace);
 }
 
diff --git a/lib/values.c b/lib/values.c
index d14bec84..ffe289c2 100644
--- a/lib/values.c
+++ b/lib/values.c
@@ -130,6 +130,7 @@ static
 void bt_value_string_destroy(struct bt_value *object)
 {
 	g_string_free(BT_VALUE_TO_STRING(object)->gstr, TRUE);
+	BT_VALUE_TO_STRING(object)->gstr = NULL;
 }
 
 static
@@ -140,6 +141,7 @@ void bt_value_array_destroy(struct bt_value *object)
 	 * of putting each contained object.
 	 */
 	g_ptr_array_free(BT_VALUE_TO_ARRAY(object)->garray, TRUE);
+	BT_VALUE_TO_ARRAY(object)->garray = NULL;
 }
 
 static
@@ -151,6 +153,7 @@ void bt_value_map_destroy(struct bt_value *object)
 	 * be destroyed anyway.
 	 */
 	g_hash_table_destroy(BT_VALUE_TO_MAP(object)->ght);
+	BT_VALUE_TO_MAP(object)->ght = NULL;
 }
 
 static
-- 
2.34.1