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 {
  73         struct declaration_struct *struct_declaration;
  74         struct declaration *declaration;
  75
  76         struct_declaration = g_new(struct declaration_struct, 1);
  77         declaration = &struct_declaration->p;
  78         struct_declaration->fields_by_name = g_hash_table_new(g_direct_hash,
  79                                                        g_direct_equal);
  80         struct_declaration->fields = g_array_sized_new(FALSE, TRUE,
  81                                                 sizeof(struct declaration_field),
  82                                                 DEFAULT_NR_STRUCT_FIELDS);
  83         struct_declaration->scope = new_declaration_scope(parent_scope);
  84         declaration->id = CTF_TYPE_STRUCT;
  85         declaration->alignment = 1;
  86         declaration->declaration_free = _struct_declaration_free;
  87         declaration->definition_new = _struct_definition_new;
  88         declaration->definition_free = _struct_definition_free;
  89         declaration->ref = 1;
  90         return struct_declaration;
  91 }
  92
  93 static
  94 struct definition *
  95         _struct_definition_new(struct declaration *declaration,
  96                                struct definition_scope *parent_scope,
  97                                GQuark field_name, int index)
  98 {
  99         struct declaration_struct *struct_declaration =
 100                 container_of(declaration, struct declaration_struct, p);
 101         struct definition_struct *_struct;
 102         unsigned long i;
 103         int ret;
 104
 105         _struct = g_new(struct definition_struct, 1);
 106         declaration_ref(&struct_declaration->p);
 107         _struct->p.declaration = declaration;
 108         _struct->declaration = struct_declaration;
 109         _struct->p.ref = 1;
 110         _struct->p.index = index;
 111         _struct->p.name = field_name;
 112         _struct->scope = new_definition_scope(parent_scope, field_name);
 113         _struct->fields = g_ptr_array_sized_new(DEFAULT_NR_STRUCT_FIELDS);
 114         g_ptr_array_set_size(_struct->fields, struct_declaration->fields->len);
 115         for (i = 0; i < struct_declaration->fields->len; i++) {
 116                 struct declaration_field *declaration_field =
 117                         &g_array_index(struct_declaration->fields,
 118                                        struct declaration_field, i);
 119                 struct definition **field =
 120                         (struct definition **) &g_ptr_array_index(_struct->fields, i);
 121
 122                 *field = declaration_field->declaration->definition_new(declaration_field->declaration,
 123                                                           _struct->scope,
 124                                                           declaration_field->name, i);
 125                 ret = register_field_definition(declaration_field->name,
 126                                                 *field,
 127                                                 _struct->scope);
 128                 assert(!ret);
 129         }
 130         return &_struct->p;
 131 }
 132
 133 static
 134 void _struct_definition_free(struct definition *definition)
 135 {
 136         struct definition_struct *_struct =
 137                 container_of(definition, struct definition_struct, p);
 138         unsigned long i;
 139
 140         assert(_struct->fields->len == _struct->declaration->fields->len);
 141         for (i = 0; i < _struct->fields->len; i++) {
 142                 struct definition *field = g_ptr_array_index(_struct->fields, i);
 143                 definition_unref(field);
 144         }
 145         free_definition_scope(_struct->scope);
 146         declaration_unref(_struct->p.declaration);
 147         g_free(_struct);
 148 }
 149
 150 void struct_declaration_add_field(struct declaration_struct *struct_declaration,
 151                            const char *field_name,
 152                            struct declaration *field_declaration)
 153 {
 154         struct declaration_field *field;
 155         unsigned long index;
 156
 157         g_array_set_size(struct_declaration->fields, struct_declaration->fields->len + 1);
 158         index = struct_declaration->fields->len - 1;    /* last field (new) */
 159         field = &g_array_index(struct_declaration->fields, struct declaration_field, index);
 160         field->name = g_quark_from_string(field_name);
 161         declaration_ref(field_declaration);
 162         field->declaration = field_declaration;
 163         /* Keep index in hash rather than pointer, because array can relocate */
 164         g_hash_table_insert(struct_declaration->fields_by_name,
 165                             (gpointer) (unsigned long) field->name,
 166                             (gpointer) index);
 167         /*
 168          * Alignment of structure is the max alignment of declarations contained
 169          * therein.
 170          */
 171         struct_declaration->p.alignment = max(struct_declaration->p.alignment,
 172                                        field_declaration->alignment);
 173 }
 174
 175 /*
 176  * struct_declaration_lookup_field_index - returns field index
 177  *
 178  * Returns the index of a field in a structure, or -1 if it does not
 179  * exist.
 180  */
 181 int struct_declaration_lookup_field_index(struct declaration_struct *struct_declaration,
 182                                        GQuark field_name)
 183 {
 184         gpointer index;
 185         gboolean found;
 186
 187         found = g_hash_table_lookup_extended(struct_declaration->fields_by_name,
 188                                     (gconstpointer) (unsigned long) field_name,
 189                                     NULL, &index);
 190         if (!found)
 191                 return -1;
 192         return (int) (unsigned long) index;
 193 }
 194
 195 /*
 196  * field returned only valid as long as the field structure is not appended to.
 197  */
 198 struct declaration_field *
 199         struct_declaration_get_field_from_index(struct declaration_struct *struct_declaration,
 200                                          int index)
 201 {
 202         if (index < 0)
 203                 return NULL;
 204         return &g_array_index(struct_declaration->fields, struct declaration_field, index);
 205 }
 206
 207 /*
 208  * field returned only valid as long as the field structure is not appended to.
 209  */
 210 struct definition *
 211 struct_definition_get_field_from_index(struct definition_struct *_struct,
 212                                         int index)
 213 {
 214         if (index < 0)
 215                 return NULL;
 216         return g_ptr_array_index(_struct->fields, index);
 217 }