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