Be more widely accepting for missing variant/enum fields
[babeltrace.git] / types / variant.c
1 /*
2 * variant.c
3 *
4 * BabelTrace - Variant Type Converter
5 *
6 * Copyright 2010-2011 EfficiOS Inc. and Linux Foundation
7 *
8 * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
9 *
10 * Permission is hereby granted, free of charge, to any person obtaining a copy
11 * of this software and associated documentation files (the "Software"), to deal
12 * in the Software without restriction, including without limitation the rights
13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14 * copies of the Software, and to permit persons to whom the Software is
15 * furnished to do so, subject to the following conditions:
16 *
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
23 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
26 * SOFTWARE.
27 */
28
29 #include <babeltrace/compiler.h>
30 #include <babeltrace/format.h>
31 #include <babeltrace/types.h>
32 #include <errno.h>
33
34 static
35 struct bt_definition *_variant_definition_new(struct bt_declaration *declaration,
36 struct definition_scope *parent_scope,
37 GQuark field_name, int index,
38 const char *root_name);
39 static
40 void _variant_definition_free(struct bt_definition *definition);
41
42 int bt_variant_rw(struct bt_stream_pos *ppos, struct bt_definition *definition)
43 {
44 struct definition_variant *variant_definition =
45 container_of(definition, struct definition_variant, p);
46 struct bt_definition *field;
47
48 field = bt_variant_get_current_field(variant_definition);
49 return generic_rw(ppos, field);
50 }
51
52 static
53 void _untagged_variant_declaration_free(struct bt_declaration *declaration)
54 {
55 struct declaration_untagged_variant *untagged_variant_declaration =
56 container_of(declaration, struct declaration_untagged_variant, p);
57 unsigned long i;
58
59 bt_free_declaration_scope(untagged_variant_declaration->scope);
60 g_hash_table_destroy(untagged_variant_declaration->fields_by_tag);
61
62 for (i = 0; i < untagged_variant_declaration->fields->len; i++) {
63 struct declaration_field *declaration_field =
64 &g_array_index(untagged_variant_declaration->fields,
65 struct declaration_field, i);
66 bt_declaration_unref(declaration_field->declaration);
67 }
68 g_array_free(untagged_variant_declaration->fields, true);
69 g_free(untagged_variant_declaration);
70 }
71
72 struct declaration_untagged_variant *bt_untagged_bt_variant_declaration_new(
73 struct declaration_scope *parent_scope)
74 {
75 struct declaration_untagged_variant *untagged_variant_declaration;
76 struct bt_declaration *declaration;
77
78 untagged_variant_declaration = g_new(struct declaration_untagged_variant, 1);
79 declaration = &untagged_variant_declaration->p;
80 untagged_variant_declaration->fields_by_tag = g_hash_table_new(g_direct_hash,
81 g_direct_equal);
82 untagged_variant_declaration->fields = g_array_sized_new(FALSE, TRUE,
83 sizeof(struct declaration_field),
84 DEFAULT_NR_STRUCT_FIELDS);
85 untagged_variant_declaration->scope = bt_new_declaration_scope(parent_scope);
86 declaration->id = CTF_TYPE_UNTAGGED_VARIANT;
87 declaration->alignment = 1;
88 declaration->declaration_free = _untagged_variant_declaration_free;
89 declaration->definition_new = NULL;
90 declaration->definition_free = NULL;
91 declaration->ref = 1;
92 return untagged_variant_declaration;
93 }
94
95 static
96 void _variant_declaration_free(struct bt_declaration *declaration)
97 {
98 struct declaration_variant *variant_declaration =
99 container_of(declaration, struct declaration_variant, p);
100
101 bt_declaration_unref(&variant_declaration->untagged_variant->p);
102 g_array_free(variant_declaration->tag_name, TRUE);
103 g_free(variant_declaration);
104 }
105
106 struct declaration_variant *
107 bt_variant_declaration_new(struct declaration_untagged_variant *untagged_variant, const char *tag)
108 {
109 struct declaration_variant *variant_declaration;
110 struct bt_declaration *declaration;
111
112 variant_declaration = g_new(struct declaration_variant, 1);
113 declaration = &variant_declaration->p;
114 variant_declaration->untagged_variant = untagged_variant;
115 bt_declaration_ref(&untagged_variant->p);
116 variant_declaration->tag_name = g_array_new(FALSE, TRUE, sizeof(GQuark));
117 bt_append_scope_path(tag, variant_declaration->tag_name);
118 declaration->id = CTF_TYPE_VARIANT;
119 declaration->alignment = 1;
120 declaration->declaration_free = _variant_declaration_free;
121 declaration->definition_new = _variant_definition_new;
122 declaration->definition_free = _variant_definition_free;
123 declaration->ref = 1;
124 return variant_declaration;
125 }
126
127 static
128 struct bt_definition *
129 _variant_definition_new(struct bt_declaration *declaration,
130 struct definition_scope *parent_scope,
131 GQuark field_name, int index,
132 const char *root_name)
133 {
134 struct declaration_variant *variant_declaration =
135 container_of(declaration, struct declaration_variant, p);
136 struct definition_variant *variant;
137 unsigned long i;
138 int ret;
139
140 variant = g_new(struct definition_variant, 1);
141 bt_declaration_ref(&variant_declaration->p);
142 variant->p.declaration = declaration;
143 variant->declaration = variant_declaration;
144 variant->p.ref = 1;
145 /*
146 * Use INT_MAX order to ensure that all fields of the parent
147 * scope are seen as being prior to this scope.
148 */
149 variant->p.index = root_name ? INT_MAX : index;
150 variant->p.name = field_name;
151 variant->p.path = bt_new_definition_path(parent_scope, field_name, root_name);
152 variant->p.scope = bt_new_definition_scope(parent_scope, field_name, root_name);
153
154 ret = bt_register_field_definition(field_name, &variant->p,
155 parent_scope);
156 assert(!ret);
157
158 variant->enum_tag = bt_lookup_path_definition(variant->p.scope->scope_path,
159 variant_declaration->tag_name,
160 parent_scope);
161
162 if (!variant->enum_tag)
163 goto error;
164 bt_definition_ref(variant->enum_tag);
165 variant->fields = g_ptr_array_sized_new(variant_declaration->untagged_variant->fields->len);
166 g_ptr_array_set_size(variant->fields, variant_declaration->untagged_variant->fields->len);
167 for (i = 0; i < variant_declaration->untagged_variant->fields->len; i++) {
168 struct declaration_field *declaration_field =
169 &g_array_index(variant_declaration->untagged_variant->fields,
170 struct declaration_field, i);
171 struct bt_definition **field =
172 (struct bt_definition **) &g_ptr_array_index(variant->fields, i);
173
174 /*
175 * All child definition are at index 0, because they are
176 * various choices of the same field.
177 */
178 *field = declaration_field->declaration->definition_new(declaration_field->declaration,
179 variant->p.scope,
180 declaration_field->name, 0, NULL);
181 if (!*field)
182 goto error;
183 }
184 variant->current_field = NULL;
185 return &variant->p;
186 error:
187 bt_free_definition_scope(variant->p.scope);
188 bt_declaration_unref(&variant_declaration->p);
189 g_free(variant);
190 return NULL;
191 }
192
193 static
194 void _variant_definition_free(struct bt_definition *definition)
195 {
196 struct definition_variant *variant =
197 container_of(definition, struct definition_variant, p);
198 unsigned long i;
199
200 assert(variant->fields->len == variant->declaration->untagged_variant->fields->len);
201 for (i = 0; i < variant->fields->len; i++) {
202 struct bt_definition *field = g_ptr_array_index(variant->fields, i);
203 bt_definition_unref(field);
204 }
205 bt_definition_unref(variant->enum_tag);
206 bt_free_definition_scope(variant->p.scope);
207 bt_declaration_unref(variant->p.declaration);
208 g_ptr_array_free(variant->fields, TRUE);
209 g_free(variant);
210 }
211
212 void bt_untagged_variant_declaration_add_field(struct declaration_untagged_variant *untagged_variant_declaration,
213 const char *field_name,
214 struct bt_declaration *field_declaration)
215 {
216 struct declaration_field *field;
217 unsigned long index;
218
219 g_array_set_size(untagged_variant_declaration->fields, untagged_variant_declaration->fields->len + 1);
220 index = untagged_variant_declaration->fields->len - 1; /* last field (new) */
221 field = &g_array_index(untagged_variant_declaration->fields, struct declaration_field, index);
222 field->name = g_quark_from_string(field_name);
223 bt_declaration_ref(field_declaration);
224 field->declaration = field_declaration;
225 /* Keep index in hash rather than pointer, because array can relocate */
226 g_hash_table_insert(untagged_variant_declaration->fields_by_tag,
227 (gpointer) (unsigned long) field->name,
228 (gpointer) index);
229 /*
230 * Alignment of variant is based on the alignment of its currently
231 * selected choice, so we leave variant alignment as-is (statically
232 * speaking).
233 */
234 }
235
236 struct declaration_field *
237 bt_untagged_variant_declaration_get_field_from_tag(struct declaration_untagged_variant *untagged_variant_declaration, GQuark tag)
238 {
239 gpointer index;
240 gboolean found;
241
242 found = g_hash_table_lookup_extended(
243 untagged_variant_declaration->fields_by_tag,
244 (gconstpointer) (unsigned long) tag, NULL, &index);
245
246 if (!found) {
247 return NULL;
248 }
249
250 return &g_array_index(untagged_variant_declaration->fields, struct declaration_field, (unsigned long)index);
251 }
252
253 /*
254 * field returned only valid as long as the field structure is not appended to.
255 */
256 struct bt_definition *bt_variant_get_current_field(struct definition_variant *variant)
257 {
258 struct definition_enum *_enum =
259 container_of(variant->enum_tag, struct definition_enum, p);
260 struct declaration_variant *variant_declaration = variant->declaration;
261 unsigned long index;
262 GArray *tag_array;
263 GQuark tag;
264
265 tag_array = _enum->value;
266 /*
267 * The 1 to 1 mapping from enumeration to value should have been already
268 * checked. (see TODO above)
269 */
270 assert(tag_array->len == 1);
271 tag = g_array_index(tag_array, GQuark, 0);
272 index = (unsigned long) g_hash_table_lookup(variant_declaration->untagged_variant->fields_by_tag,
273 (gconstpointer) (unsigned long) tag);
274 variant->current_field = g_ptr_array_index(variant->fields, index);
275 return variant->current_field;
276 }
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