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 type */
  93         GHashTable *types;
  94         struct type_scope *parent_scope;
  95 };
  96
  97 /* declaration scope */
  98 struct declaration_scope {
  99         /* Hash table mapping field name GQuark to struct declaration */
 100         GHashTable *declarations;
 101         struct declaration_scope *parent_scope;
 102 };
 103
 104 struct type {
 105         GQuark name;            /* type name */
 106         size_t alignment;       /* type alignment, in bits */
 107         int ref;                /* number of references to the type */
 108         /*
 109          * type_free called with type ref is decremented to 0.
 110          */
 111         void (*type_free)(struct type *type);
 112         struct declaration *
 113                 (*declaration_new)(struct type *type,
 114                                    struct declaration_scope *parent_scope);
 115         /*
 116          * declaration_free called with declaration ref is decremented to 0.
 117          */
 118         void (*declaration_free)(struct declaration *declaration);
 119         /*
 120          * Declaration copy function. Knows how to find the child declaration
 121          * from the parent declaration.
 122          */
 123         void (*copy)(struct stream_pos *dest, const struct format *fdest,
 124                      struct stream_pos *src, const struct format *fsrc,
 125                      struct declaration *declaration);
 126 };
 127
 128 struct declaration {
 129         struct type *type;
 130         int ref;                /* number of references to the declaration */
 131 };
 132
 133 /*
 134  * Because we address in bits, bitfields end up being exactly the same as
 135  * integers, except that their read/write functions must be able to deal with
 136  * read/write non aligned on CHAR_BIT.
 137  */
 138 struct type_integer {
 139         struct type p;
 140         size_t len;             /* length, in bits. */
 141         int byte_order;         /* byte order */
 142         int signedness;
 143 };
 144
 145 struct declaration_integer {
 146         struct declaration p;
 147         struct type_integer *type;
 148         /* Last values read */
 149         union {
 150                 uint64_t _unsigned;
 151                 int64_t _signed;
 152         } value;
 153 };
 154
 155 struct type_float {
 156         struct type p;
 157         struct type_integer *sign;
 158         struct type_integer *mantissa;
 159         struct type_integer *exp;
 160         int byte_order;
 161         /* TODO: we might want to express more info about NaN, +inf and -inf */
 162 };
 163
 164 struct declaration_float {
 165         struct declaration p;
 166         struct type_float *type;
 167         /* Last values read */
 168         long double value;
 169 };
 170
 171 /*
 172  * enum_val_equal assumes that signed and unsigned memory layout overlap.
 173  */
 174 struct enum_range {
 175         union {
 176                 int64_t _signed;
 177                 uint64_t _unsigned;
 178         } start;        /* lowest range value */
 179         union {
 180                 int64_t _signed;
 181                 uint64_t _unsigned;
 182         } end;          /* highest range value */
 183 };
 184
 185 struct enum_range_to_quark {
 186         struct cds_list_head node;
 187         struct enum_range range;
 188         GQuark quark;
 189 };
 190
 191 /*
 192  * We optimize the common case (range of size 1: single value) by creating a
 193  * hash table mapping values to quark sets. We then lookup the ranges to
 194  * complete the quark set.
 195  *
 196  * TODO: The proper structure to hold the range to quark set mapping would be an
 197  * interval tree, with O(n) size, O(n*log(n)) build time and O(log(n)) query
 198  * time. Using a simple O(n) list search for now for implementation speed and
 199  * given that we can expect to have a _relatively_ small number of enumeration
 200  * ranges. This might become untrue if we are fed with symbol tables often
 201  * required to lookup function names from instruction pointer value.
 202  */
 203 struct enum_table {
 204         GHashTable *value_to_quark_set;         /* (value, GQuark GArray) */
 205         struct cds_list_head range_to_quark;    /* (range, GQuark) */
 206         GHashTable *quark_to_range_set;         /* (GQuark, range GArray) */
 207 };
 208
 209 struct type_enum {
 210         struct type p;
 211         struct type_integer *integer_type;
 212         struct enum_table table;
 213 };
 214
 215 struct declaration_enum {
 216         struct declaration p;
 217         struct declaration_integer *integer;
 218         struct type_enum *type;
 219         /* Last GQuark values read. Keeping a reference on the GQuark array. */
 220         GArray *value;
 221 };
 222
 223 struct type_string {
 224         struct type p;
 225 };
 226
 227 struct declaration_string {
 228         struct declaration p;
 229         struct type_string *type;
 230         char *value;    /* freed at declaration_string teardown */
 231 };
 232
 233 struct type_field {
 234         GQuark name;
 235         struct type *type;
 236 };
 237
 238 struct field {
 239         GQuark name;
 240         struct declaration *declaration;
 241 };
 242
 243 struct type_struct {
 244         struct type p;
 245         GHashTable *fields_by_name;     /* Tuples (field name, field index) */
 246         struct type_scope *scope;
 247         GArray *fields;                 /* Array of type_field */
 248 };
 249
 250 struct declaration_struct {
 251         struct declaration p;
 252         struct type_struct *type;
 253         struct declaration_scope *scope;
 254         GArray *fields;                 /* Array of struct field */
 255 };
 256
 257 struct type_variant {
 258         struct type p;
 259         GHashTable *fields_by_tag;      /* Tuples (field tag, field index) */
 260         struct type_scope *scope;
 261         GArray *fields;                 /* Array of type_field */
 262 };
 263
 264 struct declaration_variant {
 265         struct declaration p;
 266         struct type_variant *type;
 267         struct declaration_scope *scope;
 268         struct declaration *enum_tag;
 269         GArray *fields;                 /* Array of struct field */
 270         struct field *current_field;    /* Last field read */
 271 };
 272
 273 struct type_array {
 274         struct type p;
 275         size_t len;
 276         struct type *elem;
 277         struct type_scope *scope;
 278 };
 279
 280 struct declaration_array {
 281         struct declaration p;
 282         struct type_array *type;
 283         struct declaration_scope *scope;
 284         struct field current_element;           /* struct field */
 285 };
 286
 287 struct type_sequence {
 288         struct type p;
 289         struct type_integer *len_type;
 290         struct type *elem;
 291         struct type_scope *scope;
 292 };
 293
 294 struct declaration_sequence {
 295         struct declaration p;
 296         struct type_sequence *type;
 297         struct declaration_scope *scope;
 298         struct declaration_integer *len;
 299         struct field current_element;           /* struct field */
 300 };
 301
 302 int register_type(GQuark type_name, struct type *type,
 303                   struct type_scope *scope);
 304 struct type *lookup_type(GQuark type_name, struct type_scope *scope);
 305 struct type_scope *new_type_scope(struct type_scope *parent_scope);
 306 void free_type_scope(struct type_scope *scope);
 307
 308 struct declaration *
 309         lookup_declaration(GQuark field_name, struct declaration_scope *scope);
 310 int register_declaration(GQuark field_name, struct declaration *declaration,
 311                          struct declaration_scope *scope);
 312 struct declaration_scope *
 313         new_declaration_scope(struct declaration_scope *parent_scope);
 314 void free_declaration_scope(struct declaration_scope *scope);
 315
 316 void type_ref(struct type *type);
 317 void type_unref(struct type *type);
 318
 319 void declaration_ref(struct declaration *declaration);
 320 void declaration_unref(struct declaration *declaration);
 321
 322 /* Nameless types can be created by passing a NULL name */
 323
 324 struct type_integer *integer_type_new(const char *name,
 325                                       size_t len, int byte_order,
 326                                       int signedness, size_t alignment);
 327
 328 /*
 329  * mantissa_len is the length of the number of bytes represented by the mantissa
 330  * (e.g. result of DBL_MANT_DIG). It includes the leading 1.
 331  */
 332 struct type_float *float_type_new(const char *name,
 333                                   size_t mantissa_len,
 334                                   size_t exp_len, int byte_order,
 335                                   size_t alignment);
 336
 337 /*
 338  * A GQuark can be translated to/from strings with g_quark_from_string() and
 339  * g_quark_to_string().
 340  */
 341
 342 /*
 343  * Returns a GArray of GQuark or NULL.
 344  * Caller must release the GArray with g_array_unref().
 345  */
 346 GArray *enum_uint_to_quark_set(const struct type_enum *enum_type, uint64_t v);
 347
 348 /*
 349  * Returns a GArray of GQuark or NULL.
 350  * Caller must release the GArray with g_array_unref().
 351  */
 352 GArray *enum_int_to_quark_set(const struct type_enum *enum_type, uint64_t v);
 353
 354 /*
 355  * Returns a GArray of struct enum_range or NULL.
 356  * Callers do _not_ own the returned GArray (and therefore _don't_ need to
 357  * release it).
 358  */
 359 GArray *enum_quark_to_range_set(const struct type_enum *enum_type, GQuark q);
 360 void enum_signed_insert(struct type_enum *enum_type,
 361                         int64_t start, int64_t end, GQuark q);
 362 void enum_unsigned_insert(struct type_enum *enum_type,
 363                           uint64_t start, uint64_t end, GQuark q);
 364 size_t enum_get_nr_enumerators(struct type_enum *enum_type);
 365
 366 struct type_enum *enum_type_new(const char *name,
 367                                 struct type_integer *integer_type);
 368
 369 struct type_struct *struct_type_new(const char *name,
 370                                     struct type_scope *parent_scope);
 371 void struct_type_add_field(struct type_struct *struct_type,
 372                            const char *field_name, struct type *field_type);
 373 /*
 374  * Returns the index of a field within a structure.
 375  */
 376 unsigned long struct_type_lookup_field_index(struct type_struct *struct_type,
 377                                              GQuark field_name);
 378 /*
 379  * field returned only valid as long as the field structure is not appended to.
 380  */
 381 struct type_field *
 382 struct_type_get_field_from_index(struct type_struct *struct_type,
 383                                  unsigned long index);
 384 struct field *
 385 struct_get_field_from_index(struct declaration_struct *struct_declaration,
 386                             unsigned long index);
 387
 388 /*
 389  * The tag enumeration is validated to ensure that it contains only mappings
 390  * from numeric values to a single tag. Overlapping tag value ranges are
 391  * therefore forbidden.
 392  */
 393 struct type_variant *variant_type_new(const char *name,
 394                                       struct type_scope *parent_scope);
 395 void variant_type_add_field(struct type_variant *variant_type,
 396                             const char *tag_name, struct type *tag_type);
 397 struct type_field *
 398 variant_type_get_field_from_tag(struct type_variant *variant_type, GQuark tag);
 399 /*
 400  * Returns 0 on success, -EPERM on error.
 401  */
 402 int variant_declaration_set_tag(struct declaration_variant *variant,
 403                                 struct declaration *enum_tag);
 404 /*
 405  * Returns the field selected by the current tag value.
 406  * field returned only valid as long as the variant structure is not appended
 407  * to.
 408  */
 409 struct field *
 410 variant_get_current_field(struct declaration_variant *variant);
 411
 412 /*
 413  * elem_type passed as parameter now belongs to the array. No need to free it
 414  * explicitly. "len" is the number of elements in the array.
 415  */
 416 struct type_array *array_type_new(const char *name,
 417                                   size_t len, struct type *elem_type,
 418                                   struct type_scope *parent_scope);
 419
 420 /*
 421  * int_type and elem_type passed as parameter now belong to the sequence. No
 422  * need to free them explicitly.
 423  */
 424 struct type_sequence *sequence_type_new(const char *name,
 425                                         struct type_integer *len_type,
 426                                         struct type *elem_type,
 427                                         struct type_scope *parent_scope);
 428
 429 #endif /* _BABELTRACE_TYPES_H */