types/struct.c

   1 /*
   2  * struct.c
   3  *
   4  * BabelTrace - Structure 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
  21 #include <babeltrace/compiler.h>
  22 #include <babeltrace/format.h>
  23 #include <babeltrace/types.h>
  24 #include <errno.h>
  25
  26 #ifndef max
  27 #define max(a, b)       ((a) < (b) ? (b) : (a))
  28 #endif
  29
  30 static
  31 struct definition *_struct_definition_new(struct declaration *declaration,
  32                                 struct definition_scope *parent_scope,
  33                                 GQuark field_name, int index,
  34                                 const char *root_name);
  35 static
  36 void _struct_definition_free(struct definition *definition);
  37
  38 int struct_rw(struct stream_pos *ppos, struct definition *definition)
  39 {
  40         struct definition_struct *struct_definition =
  41                 container_of(definition, struct definition_struct, p);
  42         unsigned long i;
  43         int ret;
  44
  45         for (i = 0; i < struct_definition->fields->len; i++) {
  46                 struct definition *field =
  47                         g_ptr_array_index(struct_definition->fields, i);
  48                 ret = generic_rw(ppos, field);
  49                 if (ret)
  50                         return ret;
  51         }
  52         return 0;
  53 }
  54
  55 static
  56 void _struct_declaration_free(struct declaration *declaration)
  57 {
  58         struct declaration_struct *struct_declaration =
  59                 container_of(declaration, struct declaration_struct, p);
  60         unsigned long i;
  61
  62         free_declaration_scope(struct_declaration->scope);
  63         g_hash_table_destroy(struct_declaration->fields_by_name);
  64
  65         for (i = 0; i < struct_declaration->fields->len; i++) {
  66                 struct declaration_field *declaration_field =
  67                         &g_array_index(struct_declaration->fields,
  68                                        struct declaration_field, i);
  69                 declaration_unref(declaration_field->declaration);
  70         }
  71         g_array_free(struct_declaration->fields, true);
  72         g_free(struct_declaration);
  73 }
  74
  75 struct declaration_struct *
  76         struct_declaration_new(struct declaration_scope *parent_scope,
  77                                uint64_t min_align)
  78 {
  79         struct declaration_struct *struct_declaration;
  80         struct declaration *declaration;
  81
  82         struct_declaration = g_new(struct declaration_struct, 1);
  83         declaration = &struct_declaration->p;
  84         struct_declaration->fields_by_name = g_hash_table_new(g_direct_hash,
  85                                                        g_direct_equal);
  86         struct_declaration->fields = g_array_sized_new(FALSE, TRUE,
  87                                                 sizeof(struct declaration_field),
  88                                                 DEFAULT_NR_STRUCT_FIELDS);
  89         struct_declaration->scope = new_declaration_scope(parent_scope);
  90         declaration->id = CTF_TYPE_STRUCT;
  91         declaration->alignment = max(1, min_align);
  92         declaration->declaration_free = _struct_declaration_free;
  93         declaration->definition_new = _struct_definition_new;
  94         declaration->definition_free = _struct_definition_free;
  95         declaration->ref = 1;
  96         return struct_declaration;
  97 }
  98
  99 static
 100 struct definition *
 101         _struct_definition_new(struct declaration *declaration,
 102                                struct definition_scope *parent_scope,
 103                                GQuark field_name, int index,
 104                                const char *root_name)
 105 {
 106         struct declaration_struct *struct_declaration =
 107                 container_of(declaration, struct declaration_struct, p);
 108         struct definition_struct *_struct;
 109         int i;
 110         int ret;
 111
 112         _struct = g_new(struct definition_struct, 1);
 113         declaration_ref(&struct_declaration->p);
 114         _struct->p.declaration = declaration;
 115         _struct->declaration = struct_declaration;
 116         _struct->p.ref = 1;
 117         /*
 118          * Use INT_MAX order to ensure that all fields of the parent
 119          * scope are seen as being prior to this scope.
 120          */
 121         _struct->p.index = root_name ? INT_MAX : index;
 122         _struct->p.name = field_name;
 123         _struct->p.path = new_definition_path(parent_scope, field_name, root_name);
 124         _struct->p.scope = new_definition_scope(parent_scope, field_name, root_name);
 125
 126         ret = register_field_definition(field_name, &_struct->p,
 127                                         parent_scope);
 128         assert(!ret || ret == -EPERM);
 129
 130         _struct->fields = g_ptr_array_sized_new(DEFAULT_NR_STRUCT_FIELDS);
 131         g_ptr_array_set_size(_struct->fields, struct_declaration->fields->len);
 132         for (i = 0; i < struct_declaration->fields->len; i++) {
 133                 struct declaration_field *declaration_field =
 134                         &g_array_index(struct_declaration->fields,
 135                                        struct declaration_field, i);
 136                 struct definition **field =
 137                         (struct definition **) &g_ptr_array_index(_struct->fields, i);
 138
 139                 *field = declaration_field->declaration->definition_new(declaration_field->declaration,
 140                                                           _struct->p.scope,
 141                                                           declaration_field->name, i, NULL);
 142                 if (!*field)
 143                         goto error;
 144         }
 145         return &_struct->p;
 146
 147 error:
 148         for (i--; i >= 0; i--) {
 149                 struct definition *field = g_ptr_array_index(_struct->fields, i);
 150                 definition_unref(field);
 151         }
 152         free_definition_scope(_struct->p.scope);
 153         declaration_unref(&struct_declaration->p);
 154         g_free(_struct);
 155         return NULL;
 156 }
 157
 158 static
 159 void _struct_definition_free(struct definition *definition)
 160 {
 161         struct definition_struct *_struct =
 162                 container_of(definition, struct definition_struct, p);
 163         unsigned long i;
 164
 165         assert(_struct->fields->len == _struct->declaration->fields->len);
 166         for (i = 0; i < _struct->fields->len; i++) {
 167                 struct definition *field = g_ptr_array_index(_struct->fields, i);
 168                 definition_unref(field);
 169         }
 170         free_definition_scope(_struct->p.scope);
 171         declaration_unref(_struct->p.declaration);
 172         g_free(_struct);
 173 }
 174
 175 void struct_declaration_add_field(struct declaration_struct *struct_declaration,
 176                            const char *field_name,
 177                            struct declaration *field_declaration)
 178 {
 179         struct declaration_field *field;
 180         unsigned long index;
 181
 182         g_array_set_size(struct_declaration->fields, struct_declaration->fields->len + 1);
 183         index = struct_declaration->fields->len - 1;    /* last field (new) */
 184         field = &g_array_index(struct_declaration->fields, struct declaration_field, index);
 185         field->name = g_quark_from_string(field_name);
 186         declaration_ref(field_declaration);
 187         field->declaration = field_declaration;
 188         /* Keep index in hash rather than pointer, because array can relocate */
 189         g_hash_table_insert(struct_declaration->fields_by_name,
 190                             (gpointer) (unsigned long) field->name,
 191                             (gpointer) index);
 192         /*
 193          * Alignment of structure is the max alignment of declarations contained
 194          * therein.
 195          */
 196         struct_declaration->p.alignment = max(struct_declaration->p.alignment,
 197                                        field_declaration->alignment);
 198 }
 199
 200 /*
 201  * struct_declaration_lookup_field_index - returns field index
 202  *
 203  * Returns the index of a field in a structure, or -1 if it does not
 204  * exist.
 205  */
 206 int struct_declaration_lookup_field_index(struct declaration_struct *struct_declaration,
 207                                        GQuark field_name)
 208 {
 209         gpointer index;
 210         gboolean found;
 211
 212         found = g_hash_table_lookup_extended(struct_declaration->fields_by_name,
 213                                     (gconstpointer) (unsigned long) field_name,
 214                                     NULL, &index);
 215         if (!found)
 216                 return -1;
 217         return (int) (unsigned long) index;
 218 }
 219
 220 /*
 221  * field returned only valid as long as the field structure is not appended to.
 222  */
 223 struct declaration_field *
 224         struct_declaration_get_field_from_index(struct declaration_struct *struct_declaration,
 225                                          int index)
 226 {
 227         if (index < 0)
 228                 return NULL;
 229         return &g_array_index(struct_declaration->fields, struct declaration_field, index);
 230 }
 231
 232 /*
 233  * field returned only valid as long as the field structure is not appended to.
 234  */
 235 struct definition *
 236 struct_definition_get_field_from_index(struct definition_struct *_struct,
 237                                         int index)
 238 {
 239         if (index < 0)
 240                 return NULL;
 241         return g_ptr_array_index(_struct->fields, index);
 242 }
 243
 244 uint64_t struct_declaration_len(struct declaration_struct *struct_declaration)
 245 {
 246         return struct_declaration->fields->len;
 247 }