| 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 definition *_variant_definition_new(struct 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 definition *definition); |
| 41 | |
| 42 | int variant_rw(struct stream_pos *ppos, struct definition *definition) |
| 43 | { |
| 44 | struct definition_variant *variant_definition = |
| 45 | container_of(definition, struct definition_variant, p); |
| 46 | struct definition *field; |
| 47 | |
| 48 | field = variant_get_current_field(variant_definition); |
| 49 | return generic_rw(ppos, field); |
| 50 | } |
| 51 | |
| 52 | static |
| 53 | void _untagged_variant_declaration_free(struct 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 | 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 *untagged_variant_declaration_new( |
| 73 | struct declaration_scope *parent_scope) |
| 74 | { |
| 75 | struct declaration_untagged_variant *untagged_variant_declaration; |
| 76 | struct 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 = 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 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 | variant_declaration_new(struct declaration_untagged_variant *untagged_variant, const char *tag) |
| 108 | { |
| 109 | struct declaration_variant *variant_declaration; |
| 110 | struct 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 | /* |
| 128 | * tag_instance is assumed to be an enumeration. |
| 129 | * Returns 0 if OK, < 0 if error. |
| 130 | */ |
| 131 | static |
| 132 | int check_enum_tag(struct definition_variant *variant, |
| 133 | struct definition *enum_tag) |
| 134 | { |
| 135 | struct definition_enum *_enum = |
| 136 | container_of(enum_tag, struct definition_enum, p); |
| 137 | struct declaration_enum *enum_declaration = _enum->declaration; |
| 138 | int missing_field = 0; |
| 139 | unsigned long i; |
| 140 | |
| 141 | /* |
| 142 | * Strictly speaking, each enumerator must map to a field of the |
| 143 | * variant. However, we are even stricter here by requiring that each |
| 144 | * variant choice map to an enumerator too. We then validate that the |
| 145 | * number of enumerators equals the number of variant choices. |
| 146 | */ |
| 147 | if (variant->declaration->untagged_variant->fields->len != enum_get_nr_enumerators(enum_declaration)) |
| 148 | return -EPERM; |
| 149 | |
| 150 | for (i = 0; i < variant->declaration->untagged_variant->fields->len; i++) { |
| 151 | struct declaration_field *field_declaration = |
| 152 | &g_array_index(variant->declaration->untagged_variant->fields, |
| 153 | struct declaration_field, i); |
| 154 | if (!enum_quark_to_range_set(enum_declaration, field_declaration->name)) { |
| 155 | missing_field = 1; |
| 156 | break; |
| 157 | } |
| 158 | } |
| 159 | if (missing_field) |
| 160 | return -EPERM; |
| 161 | |
| 162 | /* |
| 163 | * Check the enumeration: it must map each value to one and only one |
| 164 | * enumerator tag. |
| 165 | * TODO: we should also check that each range map to one and only one |
| 166 | * tag. For the moment, we will simply check this dynamically in |
| 167 | * variant_declaration_get_current_field(). |
| 168 | */ |
| 169 | return 0; |
| 170 | } |
| 171 | |
| 172 | |
| 173 | |
| 174 | static |
| 175 | struct definition * |
| 176 | _variant_definition_new(struct declaration *declaration, |
| 177 | struct definition_scope *parent_scope, |
| 178 | GQuark field_name, int index, |
| 179 | const char *root_name) |
| 180 | { |
| 181 | struct declaration_variant *variant_declaration = |
| 182 | container_of(declaration, struct declaration_variant, p); |
| 183 | struct definition_variant *variant; |
| 184 | unsigned long i; |
| 185 | int ret; |
| 186 | |
| 187 | variant = g_new(struct definition_variant, 1); |
| 188 | bt_declaration_ref(&variant_declaration->p); |
| 189 | variant->p.declaration = declaration; |
| 190 | variant->declaration = variant_declaration; |
| 191 | variant->p.ref = 1; |
| 192 | /* |
| 193 | * Use INT_MAX order to ensure that all fields of the parent |
| 194 | * scope are seen as being prior to this scope. |
| 195 | */ |
| 196 | variant->p.index = root_name ? INT_MAX : index; |
| 197 | variant->p.name = field_name; |
| 198 | variant->p.path = new_definition_path(parent_scope, field_name, root_name); |
| 199 | variant->p.scope = new_definition_scope(parent_scope, field_name, root_name); |
| 200 | |
| 201 | ret = register_field_definition(field_name, &variant->p, |
| 202 | parent_scope); |
| 203 | assert(!ret); |
| 204 | |
| 205 | variant->enum_tag = lookup_path_definition(variant->p.scope->scope_path, |
| 206 | variant_declaration->tag_name, |
| 207 | parent_scope); |
| 208 | |
| 209 | if (!variant->enum_tag |
| 210 | || check_enum_tag(variant, variant->enum_tag) < 0) |
| 211 | goto error; |
| 212 | bt_definition_ref(variant->enum_tag); |
| 213 | variant->fields = g_ptr_array_sized_new(variant_declaration->untagged_variant->fields->len); |
| 214 | g_ptr_array_set_size(variant->fields, variant_declaration->untagged_variant->fields->len); |
| 215 | for (i = 0; i < variant_declaration->untagged_variant->fields->len; i++) { |
| 216 | struct declaration_field *declaration_field = |
| 217 | &g_array_index(variant_declaration->untagged_variant->fields, |
| 218 | struct declaration_field, i); |
| 219 | struct definition **field = |
| 220 | (struct definition **) &g_ptr_array_index(variant->fields, i); |
| 221 | |
| 222 | /* |
| 223 | * All child definition are at index 0, because they are |
| 224 | * various choices of the same field. |
| 225 | */ |
| 226 | *field = declaration_field->declaration->definition_new(declaration_field->declaration, |
| 227 | variant->p.scope, |
| 228 | declaration_field->name, 0, NULL); |
| 229 | if (!*field) |
| 230 | goto error; |
| 231 | } |
| 232 | variant->current_field = NULL; |
| 233 | return &variant->p; |
| 234 | error: |
| 235 | free_definition_scope(variant->p.scope); |
| 236 | bt_declaration_unref(&variant_declaration->p); |
| 237 | g_free(variant); |
| 238 | return NULL; |
| 239 | } |
| 240 | |
| 241 | static |
| 242 | void _variant_definition_free(struct definition *definition) |
| 243 | { |
| 244 | struct definition_variant *variant = |
| 245 | container_of(definition, struct definition_variant, p); |
| 246 | unsigned long i; |
| 247 | |
| 248 | assert(variant->fields->len == variant->declaration->untagged_variant->fields->len); |
| 249 | for (i = 0; i < variant->fields->len; i++) { |
| 250 | struct definition *field = g_ptr_array_index(variant->fields, i); |
| 251 | bt_definition_unref(field); |
| 252 | } |
| 253 | bt_definition_unref(variant->enum_tag); |
| 254 | free_definition_scope(variant->p.scope); |
| 255 | bt_declaration_unref(variant->p.declaration); |
| 256 | g_ptr_array_free(variant->fields, TRUE); |
| 257 | g_free(variant); |
| 258 | } |
| 259 | |
| 260 | void untagged_variant_declaration_add_field(struct declaration_untagged_variant *untagged_variant_declaration, |
| 261 | const char *field_name, |
| 262 | struct declaration *field_declaration) |
| 263 | { |
| 264 | struct declaration_field *field; |
| 265 | unsigned long index; |
| 266 | |
| 267 | g_array_set_size(untagged_variant_declaration->fields, untagged_variant_declaration->fields->len + 1); |
| 268 | index = untagged_variant_declaration->fields->len - 1; /* last field (new) */ |
| 269 | field = &g_array_index(untagged_variant_declaration->fields, struct declaration_field, index); |
| 270 | field->name = g_quark_from_string(field_name); |
| 271 | bt_declaration_ref(field_declaration); |
| 272 | field->declaration = field_declaration; |
| 273 | /* Keep index in hash rather than pointer, because array can relocate */ |
| 274 | g_hash_table_insert(untagged_variant_declaration->fields_by_tag, |
| 275 | (gpointer) (unsigned long) field->name, |
| 276 | (gpointer) index); |
| 277 | /* |
| 278 | * Alignment of variant is based on the alignment of its currently |
| 279 | * selected choice, so we leave variant alignment as-is (statically |
| 280 | * speaking). |
| 281 | */ |
| 282 | } |
| 283 | |
| 284 | struct declaration_field * |
| 285 | untagged_variant_declaration_get_field_from_tag(struct declaration_untagged_variant *untagged_variant_declaration, GQuark tag) |
| 286 | { |
| 287 | gpointer index; |
| 288 | gboolean found; |
| 289 | |
| 290 | found = g_hash_table_lookup_extended( |
| 291 | untagged_variant_declaration->fields_by_tag, |
| 292 | (gconstpointer) (unsigned long) tag, NULL, &index); |
| 293 | |
| 294 | if (!found) { |
| 295 | return NULL; |
| 296 | } |
| 297 | |
| 298 | return &g_array_index(untagged_variant_declaration->fields, struct declaration_field, (unsigned long)index); |
| 299 | } |
| 300 | |
| 301 | /* |
| 302 | * field returned only valid as long as the field structure is not appended to. |
| 303 | */ |
| 304 | struct definition *variant_get_current_field(struct definition_variant *variant) |
| 305 | { |
| 306 | struct definition_enum *_enum = |
| 307 | container_of(variant->enum_tag, struct definition_enum, p); |
| 308 | struct declaration_variant *variant_declaration = variant->declaration; |
| 309 | unsigned long index; |
| 310 | GArray *tag_array; |
| 311 | GQuark tag; |
| 312 | |
| 313 | tag_array = _enum->value; |
| 314 | /* |
| 315 | * The 1 to 1 mapping from enumeration to value should have been already |
| 316 | * checked. (see TODO above) |
| 317 | */ |
| 318 | assert(tag_array->len == 1); |
| 319 | tag = g_array_index(tag_array, GQuark, 0); |
| 320 | index = (unsigned long) g_hash_table_lookup(variant_declaration->untagged_variant->fields_by_tag, |
| 321 | (gconstpointer) (unsigned long) tag); |
| 322 | variant->current_field = g_ptr_array_index(variant->fields, index); |
| 323 | return variant->current_field; |
| 324 | } |