--- /dev/null
+/*
+ * Copyright (C) 2018 Francis Deslauriers <francis.deslauriers@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#include <stdbool.h>
+#include <string.h>
+
+#include "ust-field-utils.h"
+
+/*
+ * The lttng_ust_ctl_field is made of a combination of C basic types
+ * lttng_ust_ctl_basic_type and _lttng_ust_ctl_basic_type.
+ *
+ * lttng_ust_ctl_basic_type contains an enumeration describing the abstract type.
+ * _lttng_ust_ctl_basic_type does _NOT_ contain an enumeration describing the
+ * abstract type.
+ *
+ * A layer is needed to use the same code for both structures.
+ * When dealing with _lttng_ust_ctl_basic_type, we need to use the abstract type of
+ * the lttng_ust_ctl_type struct.
+ */
+
+/*
+ * Compare two lttng_ust_ctl_integer_type fields.
+ * Returns 1 if both are identical.
+ */
+static bool match_lttng_ust_ctl_field_integer(const struct lttng_ust_ctl_integer_type *first,
+ const struct lttng_ust_ctl_integer_type *second)
+{
+ if (first->size != second->size) {
+ goto no_match;
+ }
+ if (first->alignment != second->alignment) {
+ goto no_match;
+ }
+ if (first->signedness != second->signedness) {
+ goto no_match;
+ }
+ if (first->encoding != second->encoding) {
+ goto no_match;
+ }
+ if (first->base != second->base) {
+ goto no_match;
+ }
+ if (first->reverse_byte_order != second->reverse_byte_order) {
+ goto no_match;
+ }
+
+ return true;
+
+no_match:
+ return false;
+}
+
+/*
+ * Compare two _lttng_ust_ctl_basic_type fields known to be of type integer.
+ * Returns 1 if both are identical.
+ */
+static bool match_lttng_ust_ctl_field_integer_from_raw_basic_type(
+ const union _lttng_ust_ctl_basic_type *first,
+ const union _lttng_ust_ctl_basic_type *second)
+{
+ return match_lttng_ust_ctl_field_integer(&first->integer, &second->integer);
+}
+
+/*
+ * Compare two _lttng_ust_ctl_basic_type fields known to be of type enum.
+ * Returns 1 if both are identical.
+ */
+static bool match_lttng_ust_ctl_field_enum_from_raw_basic_type(
+ const union _lttng_ust_ctl_basic_type *first,
+ const union _lttng_ust_ctl_basic_type *second)
+{
+ /*
+ * Compare enumeration ID. Enumeration ID is provided to the application by
+ * the session daemon before event registration.
+ */
+ if (first->enumeration.id != second->enumeration.id) {
+ goto no_match;
+ }
+
+ /*
+ * Sanity check of the name and container type. Those were already checked
+ * during enum registration.
+ */
+ if (strncmp(first->enumeration.name, second->enumeration.name,
+ LTTNG_UST_ABI_SYM_NAME_LEN)) {
+ goto no_match;
+ }
+ if (!match_lttng_ust_ctl_field_integer(&first->enumeration.container_type,
+ &second->enumeration.container_type)) {
+ goto no_match;
+ }
+
+ return true;
+
+no_match:
+ return false;
+}
+
+/*
+ * Compare two _lttng_ust_ctl_basic_type fields known to be of type string.
+ * Returns 1 if both are identical.
+ */
+static bool match_lttng_ust_ctl_field_string_from_raw_basic_type(
+ const union _lttng_ust_ctl_basic_type *first,
+ const union _lttng_ust_ctl_basic_type *second)
+{
+ return first->string.encoding == second->string.encoding;
+}
+
+/*
+ * Compare two _lttng_ust_ctl_basic_type fields known to be of type float.
+ * Returns 1 if both are identical.
+ */
+static bool match_lttng_ust_ctl_field_float_from_raw_basic_type(
+ const union _lttng_ust_ctl_basic_type *first,
+ const union _lttng_ust_ctl_basic_type *second)
+{
+ if (first->_float.exp_dig != second->_float.exp_dig) {
+ goto no_match;
+ }
+
+ if (first->_float.mant_dig != second->_float.mant_dig) {
+ goto no_match;
+ }
+
+ if (first->_float.reverse_byte_order !=
+ second->_float.reverse_byte_order) {
+ goto no_match;
+ }
+
+ if (first->_float.alignment != second->_float.alignment) {
+ goto no_match;
+ }
+
+ return true;
+
+no_match:
+ return false;
+}
+
+/*
+ * Compare two _lttng_ust_ctl_basic_type fields given their respective abstract types.
+ * Returns 1 if both are identical.
+ */
+static bool match_lttng_ust_ctl_field_raw_basic_type(
+ enum lttng_ust_ctl_abstract_types first_atype,
+ const union _lttng_ust_ctl_basic_type *first,
+ enum lttng_ust_ctl_abstract_types second_atype,
+ const union _lttng_ust_ctl_basic_type *second)
+{
+ if (first_atype != second_atype) {
+ goto no_match;
+ }
+
+ switch (first_atype) {
+ case lttng_ust_ctl_atype_integer:
+ if (!match_lttng_ust_ctl_field_integer_from_raw_basic_type(first, second)) {
+ goto no_match;
+ }
+ break;
+ case lttng_ust_ctl_atype_enum:
+ if (!match_lttng_ust_ctl_field_enum_from_raw_basic_type(first, second)) {
+ goto no_match;
+ }
+ break;
+ case lttng_ust_ctl_atype_string:
+ if (!match_lttng_ust_ctl_field_string_from_raw_basic_type(first, second)) {
+ goto no_match;
+ }
+ break;
+ case lttng_ust_ctl_atype_float:
+ if (!match_lttng_ust_ctl_field_float_from_raw_basic_type(first, second)) {
+ goto no_match;
+ }
+ break;
+ default:
+ goto no_match;
+ }
+
+ return true;
+
+no_match:
+ return false;
+}
+
+/*
+ * Compatibility layer between the lttng_ust_ctl_basic_type struct and
+ * _lttng_ust_ctl_basic_type union.
+ */
+static bool match_lttng_ust_ctl_field_basic_type(const struct lttng_ust_ctl_basic_type *first,
+ const struct lttng_ust_ctl_basic_type *second)
+{
+ return match_lttng_ust_ctl_field_raw_basic_type(first->atype, &first->u.basic,
+ second->atype, &second->u.basic);
+}
+
+int match_lttng_ust_ctl_field(const struct lttng_ust_ctl_field *first,
+ const struct lttng_ust_ctl_field *second)
+{
+ /* Check the name of the field is identical. */
+ if (strncmp(first->name, second->name, LTTNG_UST_ABI_SYM_NAME_LEN)) {
+ goto no_match;
+ }
+
+ /* Check the field type is identical. */
+ if (first->type.atype != second->type.atype) {
+ goto no_match;
+ }
+
+ /* Check the field layout. */
+ switch (first->type.atype) {
+ case lttng_ust_ctl_atype_integer:
+ case lttng_ust_ctl_atype_enum:
+ case lttng_ust_ctl_atype_string:
+ case lttng_ust_ctl_atype_float:
+ if (!match_lttng_ust_ctl_field_raw_basic_type(first->type.atype,
+ &first->type.u.legacy.basic, second->type.atype,
+ &second->type.u.legacy.basic)) {
+ goto no_match;
+ }
+ break;
+ case lttng_ust_ctl_atype_sequence:
+ /* Match element type of the sequence. */
+ if (!match_lttng_ust_ctl_field_basic_type(&first->type.u.legacy.sequence.elem_type,
+ &second->type.u.legacy.sequence.elem_type)) {
+ goto no_match;
+ }
+
+ /* Match length type of the sequence. */
+ if (!match_lttng_ust_ctl_field_basic_type(&first->type.u.legacy.sequence.length_type,
+ &second->type.u.legacy.sequence.length_type)) {
+ goto no_match;
+ }
+ break;
+ case lttng_ust_ctl_atype_array:
+ /* Match element type of the array. */
+ if (!match_lttng_ust_ctl_field_basic_type(&first->type.u.legacy.array.elem_type,
+ &second->type.u.legacy.array.elem_type)) {
+ goto no_match;
+ }
+
+ /* Match length of the array. */
+ if (first->type.u.legacy.array.length != second->type.u.legacy.array.length) {
+ goto no_match;
+ }
+ break;
+ case lttng_ust_ctl_atype_variant:
+ /* Compare number of choice of the variants. */
+ if (first->type.u.legacy.variant.nr_choices !=
+ second->type.u.legacy.variant.nr_choices) {
+ goto no_match;
+ }
+
+ /* Compare tag name of the variants. */
+ if (strncmp(first->type.u.legacy.variant.tag_name,
+ second->type.u.legacy.variant.tag_name,
+ LTTNG_UST_ABI_SYM_NAME_LEN)) {
+ goto no_match;
+ }
+ break;
+ case lttng_ust_ctl_atype_struct:
+ /* Compare number of fields of the structs. */
+ if (first->type.u.legacy._struct.nr_fields != second->type.u.legacy._struct.nr_fields) {
+ goto no_match;
+ }
+ break;
+ case lttng_ust_ctl_atype_sequence_nestable:
+ if (first->type.u.sequence_nestable.alignment != second->type.u.sequence_nestable.alignment) {
+ goto no_match;
+ }
+ /* Compare length_name of the sequences. */
+ if (strncmp(first->type.u.sequence_nestable.length_name,
+ second->type.u.sequence_nestable.length_name,
+ LTTNG_UST_ABI_SYM_NAME_LEN)) {
+ goto no_match;
+ }
+ /* Comparison will be done when marshalling following items. */
+ break;
+ case lttng_ust_ctl_atype_array_nestable:
+ if (first->type.u.array_nestable.alignment != second->type.u.array_nestable.alignment) {
+ goto no_match;
+ }
+ /* Match length of the array. */
+ if (first->type.u.array_nestable.length != second->type.u.array_nestable.length) {
+ goto no_match;
+ }
+ /* Comparison of element type will be done when marshalling following item. */
+ break;
+ case lttng_ust_ctl_atype_enum_nestable:
+ if (first->type.u.enum_nestable.id != second->type.u.enum_nestable.id) {
+ goto no_match;
+ }
+ /* Compare name of the enums. */
+ if (strncmp(first->type.u.enum_nestable.name,
+ second->type.u.enum_nestable.name,
+ LTTNG_UST_ABI_SYM_NAME_LEN)) {
+ goto no_match;
+ }
+ /* Comparison of element type will be done when marshalling following item. */
+ break;
+ case lttng_ust_ctl_atype_struct_nestable:
+ if (first->type.u.struct_nestable.alignment != second->type.u.struct_nestable.alignment) {
+ goto no_match;
+ }
+ /* Compare number of fields of the structs. */
+ if (first->type.u.struct_nestable.nr_fields != second->type.u.struct_nestable.nr_fields) {
+ goto no_match;
+ }
+ break;
+ case lttng_ust_ctl_atype_variant_nestable:
+ if (first->type.u.variant_nestable.alignment != second->type.u.variant_nestable.alignment) {
+ goto no_match;
+ }
+ /* Compare number of choice of the variants. */
+ if (first->type.u.variant_nestable.nr_choices !=
+ second->type.u.variant_nestable.nr_choices) {
+ goto no_match;
+ }
+
+ /* Compare tag name of the variants. */
+ if (strncmp(first->type.u.variant_nestable.tag_name,
+ second->type.u.variant_nestable.tag_name,
+ LTTNG_UST_ABI_SYM_NAME_LEN)) {
+ goto no_match;
+ }
+ break;
+ default:
+ goto no_match;
+ }
+
+ return true;
+
+no_match:
+ return false;
+}