types/struct.c

   1 /*
   2  * struct.c
   3  *
   4  * BabelTrace - Structure Type Converter
   5  *
   6  * Copyright 2010, 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a copy
   9  * of this software and associated documentation files (the "Software"), to deal
  10  * in the Software without restriction, including without limitation the rights
  11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12  * copies of the Software, and to permit persons to whom the Software is
  13  * furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  */
  18
  19 #include <babeltrace/compiler.h>
  20 #include <babeltrace/format.h>
  21 #include <errno.h>
  22
  23 #ifndef max
  24 #define max(a, b)       ((a) < (b) ? (b) : (a))
  25 #endif
  26
  27 static
  28 struct definition *_struct_definition_new(struct declaration *declaration,
  29                                 struct definition_scope *parent_scope,
  30                                 GQuark field_name, int index,
  31                                 const char *root_name);
  32 static
  33 void _struct_definition_free(struct definition *definition);
  34
  35 int struct_rw(struct stream_pos *ppos, struct definition *definition)
  36 {
  37         struct definition_struct *struct_definition =
  38                 container_of(definition, struct definition_struct, p);
  39         unsigned long i;
  40         int ret;
  41
  42         for (i = 0; i < struct_definition->fields->len; i++) {
  43                 struct definition *field =
  44                         g_ptr_array_index(struct_definition->fields, i);
  45                 ret = generic_rw(ppos, field);
  46                 if (ret)
  47                         return ret;
  48         }
  49         return 0;
  50 }
  51
  52 static
  53 void _struct_declaration_free(struct declaration *declaration)
  54 {
  55         struct declaration_struct *struct_declaration =
  56                 container_of(declaration, struct declaration_struct, p);
  57         unsigned long i;
  58
  59         free_declaration_scope(struct_declaration->scope);
  60         g_hash_table_destroy(struct_declaration->fields_by_name);
  61
  62         for (i = 0; i < struct_declaration->fields->len; i++) {
  63                 struct declaration_field *declaration_field =
  64                         &g_array_index(struct_declaration->fields,
  65                                        struct declaration_field, i);
  66                 declaration_unref(declaration_field->declaration);
  67         }
  68         g_array_free(struct_declaration->fields, true);
  69         g_free(struct_declaration);
  70 }
  71
  72 struct declaration_struct *
  73         struct_declaration_new(struct declaration_scope *parent_scope,
  74                                uint64_t min_align)
  75 {
  76         struct declaration_struct *struct_declaration;
  77         struct declaration *declaration;
  78
  79         struct_declaration = g_new(struct declaration_struct, 1);
  80         declaration = &struct_declaration->p;
  81         struct_declaration->fields_by_name = g_hash_table_new(g_direct_hash,
  82                                                        g_direct_equal);
  83         struct_declaration->fields = g_array_sized_new(FALSE, TRUE,
  84                                                 sizeof(struct declaration_field),
  85                                                 DEFAULT_NR_STRUCT_FIELDS);
  86         struct_declaration->scope = new_declaration_scope(parent_scope);
  87         declaration->id = CTF_TYPE_STRUCT;
  88         declaration->alignment = max(1, min_align);
  89         declaration->declaration_free = _struct_declaration_free;
  90         declaration->definition_new = _struct_definition_new;
  91         declaration->definition_free = _struct_definition_free;
  92         declaration->ref = 1;
  93         return struct_declaration;
  94 }
  95
  96 static
  97 struct definition *
  98         _struct_definition_new(struct declaration *declaration,
  99                                struct definition_scope *parent_scope,
 100                                GQuark field_name, int index,
 101                                const char *root_name)
 102 {
 103         struct declaration_struct *struct_declaration =
 104                 container_of(declaration, struct declaration_struct, p);
 105         struct definition_struct *_struct;
 106         int i;
 107         int ret;
 108
 109         _struct = g_new(struct definition_struct, 1);
 110         declaration_ref(&struct_declaration->p);
 111         _struct->p.declaration = declaration;
 112         _struct->declaration = struct_declaration;
 113         _struct->p.ref = 1;
 114         /*
 115          * Use INT_MAX order to ensure that all fields of the parent
 116          * scope are seen as being prior to this scope.
 117          */
 118         _struct->p.index = root_name ? INT_MAX : index;
 119         _struct->p.name = field_name;
 120         _struct->p.path = new_definition_path(parent_scope, field_name, root_name);
 121         _struct->p.scope = new_definition_scope(parent_scope, field_name, root_name);
 122
 123         ret = register_field_definition(field_name, &_struct->p,
 124                                         parent_scope);
 125         assert(!ret || ret == -EPERM);
 126
 127         _struct->fields = g_ptr_array_sized_new(DEFAULT_NR_STRUCT_FIELDS);
 128         g_ptr_array_set_size(_struct->fields, struct_declaration->fields->len);
 129         for (i = 0; i < struct_declaration->fields->len; i++) {
 130                 struct declaration_field *declaration_field =
 131                         &g_array_index(struct_declaration->fields,
 132                                        struct declaration_field, i);
 133                 struct definition **field =
 134                         (struct definition **) &g_ptr_array_index(_struct->fields, i);
 135
 136                 *field = declaration_field->declaration->definition_new(declaration_field->declaration,
 137                                                           _struct->p.scope,
 138                                                           declaration_field->name, i, NULL);
 139                 if (!*field)
 140                         goto error;
 141         }
 142         return &_struct->p;
 143
 144 error:
 145         for (i--; i >= 0; i--) {
 146                 struct definition *field = g_ptr_array_index(_struct->fields, i);
 147                 definition_unref(field);
 148         }
 149         free_definition_scope(_struct->p.scope);
 150         declaration_unref(&struct_declaration->p);
 151         g_free(_struct);
 152         return NULL;
 153 }
 154
 155 static
 156 void _struct_definition_free(struct definition *definition)
 157 {
 158         struct definition_struct *_struct =
 159                 container_of(definition, struct definition_struct, p);
 160         unsigned long i;
 161
 162         assert(_struct->fields->len == _struct->declaration->fields->len);
 163         for (i = 0; i < _struct->fields->len; i++) {
 164                 struct definition *field = g_ptr_array_index(_struct->fields, i);
 165                 definition_unref(field);
 166         }
 167         free_definition_scope(_struct->p.scope);
 168         declaration_unref(_struct->p.declaration);
 169         g_free(_struct);
 170 }
 171
 172 void struct_declaration_add_field(struct declaration_struct *struct_declaration,
 173                            const char *field_name,
 174                            struct declaration *field_declaration)
 175 {
 176         struct declaration_field *field;
 177         unsigned long index;
 178
 179         g_array_set_size(struct_declaration->fields, struct_declaration->fields->len + 1);
 180         index = struct_declaration->fields->len - 1;    /* last field (new) */
 181         field = &g_array_index(struct_declaration->fields, struct declaration_field, index);
 182         field->name = g_quark_from_string(field_name);
 183         declaration_ref(field_declaration);
 184         field->declaration = field_declaration;
 185         /* Keep index in hash rather than pointer, because array can relocate */
 186         g_hash_table_insert(struct_declaration->fields_by_name,
 187                             (gpointer) (unsigned long) field->name,
 188                             (gpointer) index);
 189         /*
 190          * Alignment of structure is the max alignment of declarations contained
 191          * therein.
 192          */
 193         struct_declaration->p.alignment = max(struct_declaration->p.alignment,
 194                                        field_declaration->alignment);
 195 }
 196
 197 /*
 198  * struct_declaration_lookup_field_index - returns field index
 199  *
 200  * Returns the index of a field in a structure, or -1 if it does not
 201  * exist.
 202  */
 203 int struct_declaration_lookup_field_index(struct declaration_struct *struct_declaration,
 204                                        GQuark field_name)
 205 {
 206         gpointer index;
 207         gboolean found;
 208
 209         found = g_hash_table_lookup_extended(struct_declaration->fields_by_name,
 210                                     (gconstpointer) (unsigned long) field_name,
 211                                     NULL, &index);
 212         if (!found)
 213                 return -1;
 214         return (int) (unsigned long) index;
 215 }
 216
 217 /*
 218  * field returned only valid as long as the field structure is not appended to.
 219  */
 220 struct declaration_field *
 221         struct_declaration_get_field_from_index(struct declaration_struct *struct_declaration,
 222                                          int index)
 223 {
 224         if (index < 0)
 225                 return NULL;
 226         return &g_array_index(struct_declaration->fields, struct declaration_field, index);
 227 }
 228
 229 /*
 230  * field returned only valid as long as the field structure is not appended to.
 231  */
 232 struct definition *
 233 struct_definition_get_field_from_index(struct definition_struct *_struct,
 234                                         int index)
 235 {
 236         if (index < 0)
 237                 return NULL;
 238         return g_ptr_array_index(_struct->fields, index);
 239 }
 240
 241 uint64_t struct_declaration_len(struct declaration_struct *struct_declaration)
 242 {
 243         return struct_declaration->fields->len;
 244 }