Build fixes.
[babeltrace.git] / types / variant.c
CommitLineData
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1/*
2 * variant.c
3 *
4 * BabelTrace - Variant Type Converter
5 *
6 * Copyright 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>
6ee5115e 21#include <errno.h>
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22
23static
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24struct declaration *_variant_declaration_new(struct type *type,
25 struct declaration_scope *parent_scope);
c054553d 26static
e19c3d69 27void _variant_declaration_free(struct declaration *declaration);
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28
29void variant_copy(struct stream_pos *dest, const struct format *fdest,
30 struct stream_pos *src, const struct format *fsrc,
e19c3d69 31 struct declaration *declaration)
c054553d 32{
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33 struct declaration_variant *variant =
34 container_of(declaration, struct declaration_variant, p);
35 struct type_variant *variant_type = variant->type;
c054553d 36 struct field *field;
e19c3d69 37 struct type *field_type;
c054553d 38
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39 fsrc->variant_begin(src, variant_type);
40 fdest->variant_begin(dest, variant_type);
c054553d 41
e19c3d69 42 field = variant_get_current_field(variant);
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43 field_type = field->declaration->type;
44 field_type->copy(dest, fdest, src, fsrc, field->declaration);
c054553d 45
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46 fsrc->variant_end(src, variant_type);
47 fdest->variant_end(dest, variant_type);
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48}
49
50static
e19c3d69 51void _variant_type_free(struct type *type)
c054553d 52{
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53 struct type_variant *variant_type =
54 container_of(type, struct type_variant, p);
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55 unsigned long i;
56
e19c3d69 57 g_hash_table_destroy(variant_type->fields_by_tag);
c054553d 58
e19c3d69 59 for (i = 0; i < variant_type->fields->len; i++) {
6ee5115e 60 struct type_field *type_field =
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61 &g_array_index(variant_type->fields,
62 struct type_field, i);
6ee5115e 63 type_unref(type_field->type);
c054553d 64 }
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65 g_array_free(variant_type->fields, true);
66 g_free(variant_type);
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67}
68
e19c3d69 69struct type_variant *variant_type_new(const char *name)
c054553d 70{
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71 struct type_variant *variant_type;
72 struct type *type;
c054553d 73
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74 variant_type = g_new(struct type_variant, 1);
75 type = &variant_type->p;
76 variant_type->fields_by_tag = g_hash_table_new(g_direct_hash,
77 g_direct_equal);
78 variant_type->fields = g_array_sized_new(FALSE, TRUE,
79 sizeof(struct type_field),
80 DEFAULT_NR_STRUCT_FIELDS);
81 type->name = g_quark_from_string(name);
82 type->alignment = 1;
83 type->copy = variant_copy;
84 type->type_free = _variant_type_free;
85 type->declaration_new = _variant_declaration_new;
86 type->declaration_free = _variant_declaration_free;
87 type->ref = 1;
e19c3d69 88 return variant_type;
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89}
90
91static
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92struct declaration *
93 _variant_declaration_new(struct type *type,
94 struct declaration_scope *parent_scope)
c054553d 95{
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96 struct type_variant *variant_type =
97 container_of(type, struct type_variant, p);
98 struct declaration_variant *variant;
c054553d 99
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100 variant = g_new(struct declaration_variant, 1);
101 type_ref(&variant_type->p);
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102 variant->p.type = type;
103 variant->type = variant_type;
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104 variant->p.ref = 1;
105 variant->scope = new_declaration_scope(parent_scope);
106 variant->fields = g_array_sized_new(FALSE, TRUE,
107 sizeof(struct field),
108 DEFAULT_NR_STRUCT_FIELDS);
109 variant->current_field = NULL;
110 return &variant->p;
111}
112
113static
6ee5115e 114void _variant_declaration_free(struct declaration *declaration)
c054553d 115{
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116 struct declaration_variant *variant =
117 container_of(declaration, struct declaration_variant, p);
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118 unsigned long i;
119
120 for (i = 0; i < variant->fields->len; i++) {
121 struct field *field = &g_array_index(variant->fields,
122 struct field, i);
e19c3d69 123 declaration_unref(field->declaration);
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124 }
125 free_declaration_scope(variant->scope);
e19c3d69 126 type_unref(variant->p.type);
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127 g_free(variant);
128}
129
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130void variant_type_add_field(struct type_variant *variant_type,
131 const char *tag_name,
132 struct type *tag_type)
c054553d 133{
e19c3d69 134 struct type_field *field;
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135 unsigned long index;
136
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137 g_array_set_size(variant_type->fields, variant_type->fields->len + 1);
138 index = variant_type->fields->len - 1; /* last field (new) */
139 field = &g_array_index(variant_type->fields, struct type_field, index);
c054553d 140 field->name = g_quark_from_string(tag_name);
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141 type_ref(tag_type);
142 field->type = tag_type;
c054553d 143 /* Keep index in hash rather than pointer, because array can relocate */
6ee5115e 144 g_hash_table_insert(variant_type->fields_by_tag,
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145 (gpointer) (unsigned long) field->name,
146 (gpointer) index);
147 /*
148 * Alignment of variant is based on the alignment of its currently
149 * selected choice, so we leave variant alignment as-is (statically
150 * speaking).
151 */
152}
153
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154struct type_field *
155struct_type_get_field_from_tag(struct type_variant *variant_type, GQuark tag)
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156{
157 unsigned long index;
158
e19c3d69 159 index = (unsigned long) g_hash_table_lookup(variant_type->fields_by_tag,
c054553d 160 (gconstpointer) (unsigned long) tag);
e19c3d69 161 return &g_array_index(variant_type->fields, struct type_field, index);
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162}
163
164/*
165 * tag_instance is assumed to be an enumeration.
166 */
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167int variant_declaration_set_tag(struct declaration_variant *variant,
168 struct declaration *enum_tag)
c054553d 169{
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170 struct declaration_enum *_enum =
171 container_of(variant->enum_tag, struct declaration_enum, p);
172 struct type_enum *enum_type = _enum->type;
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173 int missing_field = 0;
174 unsigned long i;
175
176 /*
177 * Strictly speaking, each enumerator must map to a field of the
178 * variant. However, we are even stricter here by requiring that each
179 * variant choice map to an enumerator too. We then validate that the
180 * number of enumerators equals the number of variant choices.
181 */
e19c3d69 182 if (variant->type->fields->len != enum_get_nr_enumerators(enum_type))
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183 return -EPERM;
184
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185 for (i = 0; i < variant->type->fields->len; i++) {
186 struct type_field *field_type =
187 &g_array_index(variant->type->fields,
188 struct type_field, i);
189 if (!enum_quark_to_range_set(enum_type, field_type->name)) {
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190 missing_field = 1;
191 break;
192 }
193 }
194 if (missing_field)
195 return -EPERM;
196
197 /*
198 * Check the enumeration: it must map each value to one and only one
199 * enumerator tag.
200 * TODO: we should also check that each range map to one and only one
201 * tag. For the moment, we will simply check this dynamically in
202 * variant_type_get_current_field().
203 */
204
205 /* Set the enum tag field */
e19c3d69 206 variant->enum_tag = enum_tag;
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207 return 0;
208}
209
210/*
211 * field returned only valid as long as the field structure is not appended to.
212 */
e19c3d69 213struct field *variant_get_current_field(struct declaration_variant *variant)
c054553d 214{
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215 struct declaration_enum *_enum =
216 container_of(variant->enum_tag, struct declaration_enum, p);
6ee5115e 217 struct type_variant *variant_type = variant->type;
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218 unsigned long index;
219 GArray *tag_array;
220 GQuark tag;
221
222 tag_array = _enum->value;
223 /*
224 * The 1 to 1 mapping from enumeration to value should have been already
225 * checked. (see TODO above)
226 */
227 assert(tag_array->len == 1);
228 tag = g_array_index(tag_array, GQuark, 0);
e19c3d69 229 index = (unsigned long) g_hash_table_lookup(variant_type->fields_by_tag,
c054553d 230 (gconstpointer) (unsigned long) tag);
e19c3d69 231 variant->current_field = &g_array_index(variant->fields, struct field, index);
96354dac 232 return variant->current_field;
c054553d 233}
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