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