include/babeltrace/types.h

   1 #ifndef _BABELTRACE_TYPES_H
   2 #define _BABELTRACE_TYPES_H
   3
   4 /*
   5  * BabelTrace
   6  *
   7  * Type Header
   8  *
   9  * Copyright 2010, 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a copy
  12  * of this software and associated documentation files (the "Software"), to deal
  13  * in the Software without restriction, including without limitation the rights
  14  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15  * copies of the Software, and to permit persons to whom the Software is
  16  * furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included in
  19  * all copies or substantial portions of the Software.
  20  */
  21
  22 #include <babeltrace/align.h>
  23 #include <babeltrace/list.h>
  24 #include <stdbool.h>
  25 #include <stdint.h>
  26 #include <limits.h>
  27 #include <string.h>
  28 #include <glib.h>
  29 #include <assert.h>
  30
  31 /* Preallocate this many fields for structures */
  32 #define DEFAULT_NR_STRUCT_FIELDS 8
  33
  34 /*
  35  * Always update stream_pos with move_pos and init_pos.
  36  */
  37 struct stream_pos {
  38         char *base;             /* Base address */
  39         size_t offset;          /* Offset from base, in bits */
  40         int dummy;              /* Dummy position, for length calculation */
  41 };
  42
  43 static inline
  44 void init_pos(struct stream_pos *pos, char *base)
  45 {
  46         pos->base = base;       /* initial base, page-aligned */
  47         pos->offset = 0;
  48         pos->dummy = false;
  49 }
  50
  51 /*
  52  * move_pos - move position of a relative bit offset
  53  *
  54  * TODO: allow larger files by updating base too.
  55  */
  56 static inline
  57 void move_pos(struct stream_pos *pos, size_t offset)
  58 {
  59         pos->offset = pos->offset + offset;
  60 }
  61
  62 /*
  63  * align_pos - align position on a bit offset (> 0)
  64  *
  65  * TODO: allow larger files by updating base too.
  66  */
  67 static inline
  68 void align_pos(struct stream_pos *pos, size_t offset)
  69 {
  70         pos->offset += offset_align(pos->offset, offset);
  71 }
  72
  73 static inline
  74 void copy_pos(struct stream_pos *dest, struct stream_pos *src)
  75 {
  76         memcpy(dest, src, sizeof(struct stream_pos));
  77 }
  78
  79 static inline
  80 char *get_pos_addr(struct stream_pos *pos)
  81 {
  82         /* Only makes sense to get the address after aligning on CHAR_BIT */
  83         assert(!(pos->offset % CHAR_BIT));
  84         return pos->base + (pos->offset / CHAR_BIT);
  85 }
  86
  87 struct format;
  88 struct declaration;
  89
  90 /* type scope */
  91 struct type_scope {
  92         /* Hash table mapping type name GQuark to "struct declaration" */
  93         GHashTable *type_declarations;
  94         /* Hash table mapping struct name GQuark to "struct type_struct" */
  95         GHashTable *struct_types;
  96         /* Hash table mapping variant name GQuark to "struct type_variant" */
  97         GHashTable *variant_types;
  98         /* Hash table mapping enum name GQuark to "struct type_enum" */
  99         GHashTable *enum_types;
 100         struct type_scope *parent_scope;
 101 };
 102
 103 /* declaration scope */
 104 struct declaration_scope {
 105         /* Hash table mapping field name GQuark to "struct declaration" */
 106         GHashTable *declarations;
 107         struct declaration_scope *parent_scope;
 108 };
 109
 110 enum ctf_type_id {
 111         CTF_TYPE_UNKNOWN = 0,
 112         CTF_TYPE_INTEGER,
 113         CTF_TYPE_FLOAT,
 114         CTF_TYPE_ENUM,
 115         CTF_TYPE_STRING,
 116         CTF_TYPE_STRUCT,
 117         CTF_TYPE_VARIANT,
 118         CTF_TYPE_ARRAY,
 119         CTF_TYPE_SEQUENCE,
 120         NR_CTF_TYPES,
 121 };
 122
 123 struct type {
 124         enum ctf_type_id id;
 125         GQuark name;            /* type name */
 126         size_t alignment;       /* type alignment, in bits */
 127         int ref;                /* number of references to the type */
 128         /*
 129          * type_free called with type ref is decremented to 0.
 130          */
 131         void (*type_free)(struct type *type);
 132         struct declaration *
 133                 (*declaration_new)(struct type *type,
 134                                    struct declaration_scope *parent_scope);
 135         /*
 136          * declaration_free called with declaration ref is decremented to 0.
 137          */
 138         void (*declaration_free)(struct declaration *declaration);
 139         /*
 140          * Declaration copy function. Knows how to find the child declaration
 141          * from the parent declaration.
 142          */
 143         void (*copy)(struct stream_pos *dest, const struct format *fdest,
 144                      struct stream_pos *src, const struct format *fsrc,
 145                      struct declaration *declaration);
 146 };
 147
 148 struct declaration {
 149         struct type *type;
 150         int ref;                /* number of references to the declaration */
 151 };
 152
 153 /*
 154  * Because we address in bits, bitfields end up being exactly the same as
 155  * integers, except that their read/write functions must be able to deal with
 156  * read/write non aligned on CHAR_BIT.
 157  */
 158 struct type_integer {
 159         struct type p;
 160         size_t len;             /* length, in bits. */
 161         int byte_order;         /* byte order */
 162         int signedness;
 163 };
 164
 165 struct declaration_integer {
 166         struct declaration p;
 167         struct type_integer *type;
 168         /* Last values read */
 169         union {
 170                 uint64_t _unsigned;
 171                 int64_t _signed;
 172         } value;
 173 };
 174
 175 struct type_float {
 176         struct type p;
 177         struct type_integer *sign;
 178         struct type_integer *mantissa;
 179         struct type_integer *exp;
 180         int byte_order;
 181         /* TODO: we might want to express more info about NaN, +inf and -inf */
 182 };
 183
 184 struct declaration_float {
 185         struct declaration p;
 186         struct type_float *type;
 187         /* Last values read */
 188         long double value;
 189 };
 190
 191 /*
 192  * enum_val_equal assumes that signed and unsigned memory layout overlap.
 193  */
 194 struct enum_range {
 195         union {
 196                 int64_t _signed;
 197                 uint64_t _unsigned;
 198         } start;        /* lowest range value */
 199         union {
 200                 int64_t _signed;
 201                 uint64_t _unsigned;
 202         } end;          /* highest range value */
 203 };
 204
 205 struct enum_range_to_quark {
 206         struct cds_list_head node;
 207         struct enum_range range;
 208         GQuark quark;
 209 };
 210
 211 /*
 212  * We optimize the common case (range of size 1: single value) by creating a
 213  * hash table mapping values to quark sets. We then lookup the ranges to
 214  * complete the quark set.
 215  *
 216  * TODO: The proper structure to hold the range to quark set mapping would be an
 217  * interval tree, with O(n) size, O(n*log(n)) build time and O(log(n)) query
 218  * time. Using a simple O(n) list search for now for implementation speed and
 219  * given that we can expect to have a _relatively_ small number of enumeration
 220  * ranges. This might become untrue if we are fed with symbol tables often
 221  * required to lookup function names from instruction pointer value.
 222  */
 223 struct enum_table {
 224         GHashTable *value_to_quark_set;         /* (value, GQuark GArray) */
 225         struct cds_list_head range_to_quark;    /* (range, GQuark) */
 226         GHashTable *quark_to_range_set;         /* (GQuark, range GArray) */
 227 };
 228
 229 struct type_enum {
 230         struct type p;
 231         struct type_integer *integer_type;
 232         struct enum_table table;
 233 };
 234
 235 struct declaration_enum {
 236         struct declaration p;
 237         struct declaration_integer *integer;
 238         struct type_enum *type;
 239         /* Last GQuark values read. Keeping a reference on the GQuark array. */
 240         GArray *value;
 241 };
 242
 243 struct type_string {
 244         struct type p;
 245 };
 246
 247 struct declaration_string {
 248         struct declaration p;
 249         struct type_string *type;
 250         char *value;    /* freed at declaration_string teardown */
 251 };
 252
 253 struct type_field {
 254         GQuark name;
 255         struct type *type;
 256 };
 257
 258 struct field {
 259         GQuark name;
 260         struct declaration *declaration;
 261 };
 262
 263 struct type_struct {
 264         struct type p;
 265         GHashTable *fields_by_name;     /* Tuples (field name, field index) */
 266         struct type_scope *scope;
 267         GArray *fields;                 /* Array of type_field */
 268 };
 269
 270 struct declaration_struct {
 271         struct declaration p;
 272         struct type_struct *type;
 273         struct declaration_scope *scope;
 274         GArray *fields;                 /* Array of struct field */
 275 };
 276
 277 struct type_variant {
 278         struct type p;
 279         GHashTable *fields_by_tag;      /* Tuples (field tag, field index) */
 280         struct type_scope *scope;
 281         GArray *fields;                 /* Array of type_field */
 282         GQuark tag_name;                /* TODO */
 283         /* Tag name must be nonzero and must exist when defining the variant */
 284 };
 285
 286 struct declaration_variant {
 287         struct declaration p;
 288         struct type_variant *type;
 289         struct declaration_scope *scope;
 290         struct declaration *enum_tag;
 291         GArray *fields;                 /* Array of struct field */
 292         struct field *current_field;    /* Last field read */
 293 };
 294
 295 struct type_array {
 296         struct type p;
 297         size_t len;
 298         struct type *elem;
 299         struct type_scope *scope;
 300 };
 301
 302 struct declaration_array {
 303         struct declaration p;
 304         struct type_array *type;
 305         struct declaration_scope *scope;
 306         struct field current_element;           /* struct field */
 307 };
 308
 309 struct type_sequence {
 310         struct type p;
 311         struct type_integer *len_type;
 312         struct type *elem;
 313         struct type_scope *scope;
 314 };
 315
 316 struct declaration_sequence {
 317         struct declaration p;
 318         struct type_sequence *type;
 319         struct declaration_scope *scope;
 320         struct declaration_integer *len;
 321         struct field current_element;           /* struct field */
 322 };
 323
 324 /*
 325  * type_declaration is for typedef and typealias. They are registered
 326  * into type scopes.
 327  */
 328 int register_type_declaration(GQuark type_name, struct declaration *declaration,
 329                               struct type_scope *scope);
 330 struct declaration *lookup_type_declaration(GQuark type_name,
 331                                             struct type_scope *scope);
 332
 333 /*
 334  * Type scopes also contain a separate registry for struct, variant and
 335  * enum types. Those register types rather than type declarations, so
 336  * that a named variant can be declared without specifying its target
 337  * "choice" tag field immediately.
 338  */
 339 int register_struct_type(GQuark struct_name, struct type_struct *struct_type,
 340                          struct type_scope *scope);
 341 struct type_struct *lookup_struct_type(GQuark struct_name,
 342                                        struct type_scope *scope);
 343 int register_variant_type(GQuark variant_name,
 344                           struct type_variant *variant_type,
 345                           struct type_scope *scope);
 346 struct type_variant *lookup_variant_type(GQuark variant_name,
 347                                          struct type_scope *scope);
 348 int register_enum_type(GQuark enum_name, struct type_enum *enum_type,
 349                        struct type_scope *scope);
 350 struct type_enum *lookup_enum_type(GQuark enum_name,
 351                                    struct type_scope *scope);
 352
 353 struct type_scope *new_type_scope(struct type_scope *parent_scope);
 354 void free_type_scope(struct type_scope *scope);
 355
 356 /*
 357  * field_declaration is for field declarations. They are registered into
 358  * declaration scopes.
 359  */
 360 struct declaration *
 361         lookup_field_declaration(GQuark field_name,
 362                                  struct declaration_scope *scope);
 363 int register_field_declaration(GQuark field_name,
 364                                struct declaration *declaration,
 365                                struct declaration_scope *scope);
 366 struct declaration_scope *
 367         new_declaration_scope(struct declaration_scope *parent_scope);
 368 void free_declaration_scope(struct declaration_scope *scope);
 369
 370 void type_ref(struct type *type);
 371 void type_unref(struct type *type);
 372
 373 void declaration_ref(struct declaration *declaration);
 374 void declaration_unref(struct declaration *declaration);
 375
 376 /* Nameless types can be created by passing a NULL name */
 377
 378 struct type_integer *integer_type_new(const char *name,
 379                                       size_t len, int byte_order,
 380                                       int signedness, size_t alignment);
 381
 382 /*
 383  * mantissa_len is the length of the number of bytes represented by the mantissa
 384  * (e.g. result of DBL_MANT_DIG). It includes the leading 1.
 385  */
 386 struct type_float *float_type_new(const char *name,
 387                                   size_t mantissa_len,
 388                                   size_t exp_len, int byte_order,
 389                                   size_t alignment);
 390
 391 /*
 392  * A GQuark can be translated to/from strings with g_quark_from_string() and
 393  * g_quark_to_string().
 394  */
 395
 396 /*
 397  * Returns a GArray of GQuark or NULL.
 398  * Caller must release the GArray with g_array_unref().
 399  */
 400 GArray *enum_uint_to_quark_set(const struct type_enum *enum_type, uint64_t v);
 401
 402 /*
 403  * Returns a GArray of GQuark or NULL.
 404  * Caller must release the GArray with g_array_unref().
 405  */
 406 GArray *enum_int_to_quark_set(const struct type_enum *enum_type, uint64_t v);
 407
 408 /*
 409  * Returns a GArray of struct enum_range or NULL.
 410  * Callers do _not_ own the returned GArray (and therefore _don't_ need to
 411  * release it).
 412  */
 413 GArray *enum_quark_to_range_set(const struct type_enum *enum_type, GQuark q);
 414 void enum_signed_insert(struct type_enum *enum_type,
 415                         int64_t start, int64_t end, GQuark q);
 416 void enum_unsigned_insert(struct type_enum *enum_type,
 417                           uint64_t start, uint64_t end, GQuark q);
 418 size_t enum_get_nr_enumerators(struct type_enum *enum_type);
 419
 420 struct type_enum *enum_type_new(const char *name,
 421                                 struct type_integer *integer_type);
 422
 423 struct type_struct *struct_type_new(const char *name,
 424                                     struct type_scope *parent_scope);
 425 void struct_type_add_field(struct type_struct *struct_type,
 426                            const char *field_name, struct type *field_type);
 427 /*
 428  * Returns the index of a field within a structure.
 429  */
 430 unsigned long struct_type_lookup_field_index(struct type_struct *struct_type,
 431                                              GQuark field_name);
 432 /*
 433  * field returned only valid as long as the field structure is not appended to.
 434  */
 435 struct type_field *
 436 struct_type_get_field_from_index(struct type_struct *struct_type,
 437                                  unsigned long index);
 438 struct field *
 439 struct_get_field_from_index(struct declaration_struct *struct_declaration,
 440                             unsigned long index);
 441
 442 /*
 443  * The tag enumeration is validated to ensure that it contains only mappings
 444  * from numeric values to a single tag. Overlapping tag value ranges are
 445  * therefore forbidden.
 446  */
 447 struct type_variant *variant_type_new(const char *name,
 448                                       struct type_scope *parent_scope);
 449 void variant_type_add_field(struct type_variant *variant_type,
 450                             const char *tag_name, struct type *tag_type);
 451 struct type_field *
 452 variant_type_get_field_from_tag(struct type_variant *variant_type, GQuark tag);
 453 /*
 454  * Returns 0 on success, -EPERM on error.
 455  */
 456 int variant_declaration_set_tag(struct declaration_variant *variant,
 457                                 struct declaration *enum_tag);
 458 /*
 459  * Returns the field selected by the current tag value.
 460  * field returned only valid as long as the variant structure is not appended
 461  * to.
 462  */
 463 struct field *
 464 variant_get_current_field(struct declaration_variant *variant);
 465
 466 /*
 467  * elem_type passed as parameter now belongs to the array. No need to free it
 468  * explicitly. "len" is the number of elements in the array.
 469  */
 470 struct type_array *array_type_new(const char *name,
 471                                   size_t len, struct type *elem_type,
 472                                   struct type_scope *parent_scope);
 473
 474 /*
 475  * int_type and elem_type passed as parameter now belong to the sequence. No
 476  * need to free them explicitly.
 477  */
 478 struct type_sequence *sequence_type_new(const char *name,
 479                                         struct type_integer *len_type,
 480                                         struct type *elem_type,
 481                                         struct type_scope *parent_scope);
 482
 483 #endif /* _BABELTRACE_TYPES_H */