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 enum ctf_type_id {
 105         CTF_TYPE_UNKNOWN = 0,
 106         CTF_TYPE_INTEGER,
 107         CTF_TYPE_FLOAT,
 108         CTF_TYPE_ENUM,
 109         CTF_TYPE_STRING,
 110         CTF_TYPE_STRUCT,
 111         CTF_TYPE_VARIANT,
 112         CTF_TYPE_ARRAY,
 113         CTF_TYPE_SEQUENCE,
 114         NR_CTF_TYPES,
 115 };
 116
 117 struct type {
 118         enum ctf_type_id id;
 119         GQuark name;            /* type name */
 120         size_t alignment;       /* type alignment, in bits */
 121         int ref;                /* number of references to the type */
 122         /*
 123          * type_free called with type ref is decremented to 0.
 124          */
 125         void (*type_free)(struct type *type);
 126         struct declaration *
 127                 (*declaration_new)(struct type *type,
 128                                    struct declaration_scope *parent_scope);
 129         /*
 130          * declaration_free called with declaration ref is decremented to 0.
 131          */
 132         void (*declaration_free)(struct declaration *declaration);
 133         /*
 134          * Declaration copy function. Knows how to find the child declaration
 135          * from the parent declaration.
 136          */
 137         void (*copy)(struct stream_pos *dest, const struct format *fdest,
 138                      struct stream_pos *src, const struct format *fsrc,
 139                      struct declaration *declaration);
 140 };
 141
 142 struct declaration {
 143         struct type *type;
 144         int ref;                /* number of references to the declaration */
 145 };
 146
 147 /*
 148  * Because we address in bits, bitfields end up being exactly the same as
 149  * integers, except that their read/write functions must be able to deal with
 150  * read/write non aligned on CHAR_BIT.
 151  */
 152 struct type_integer {
 153         struct type p;
 154         size_t len;             /* length, in bits. */
 155         int byte_order;         /* byte order */
 156         int signedness;
 157 };
 158
 159 struct declaration_integer {
 160         struct declaration p;
 161         struct type_integer *type;
 162         /* Last values read */
 163         union {
 164                 uint64_t _unsigned;
 165                 int64_t _signed;
 166         } value;
 167 };
 168
 169 struct type_float {
 170         struct type p;
 171         struct type_integer *sign;
 172         struct type_integer *mantissa;
 173         struct type_integer *exp;
 174         int byte_order;
 175         /* TODO: we might want to express more info about NaN, +inf and -inf */
 176 };
 177
 178 struct declaration_float {
 179         struct declaration p;
 180         struct type_float *type;
 181         /* Last values read */
 182         long double value;
 183 };
 184
 185 /*
 186  * enum_val_equal assumes that signed and unsigned memory layout overlap.
 187  */
 188 struct enum_range {
 189         union {
 190                 int64_t _signed;
 191                 uint64_t _unsigned;
 192         } start;        /* lowest range value */
 193         union {
 194                 int64_t _signed;
 195                 uint64_t _unsigned;
 196         } end;          /* highest range value */
 197 };
 198
 199 struct enum_range_to_quark {
 200         struct cds_list_head node;
 201         struct enum_range range;
 202         GQuark quark;
 203 };
 204
 205 /*
 206  * We optimize the common case (range of size 1: single value) by creating a
 207  * hash table mapping values to quark sets. We then lookup the ranges to
 208  * complete the quark set.
 209  *
 210  * TODO: The proper structure to hold the range to quark set mapping would be an
 211  * interval tree, with O(n) size, O(n*log(n)) build time and O(log(n)) query
 212  * time. Using a simple O(n) list search for now for implementation speed and
 213  * given that we can expect to have a _relatively_ small number of enumeration
 214  * ranges. This might become untrue if we are fed with symbol tables often
 215  * required to lookup function names from instruction pointer value.
 216  */
 217 struct enum_table {
 218         GHashTable *value_to_quark_set;         /* (value, GQuark GArray) */
 219         struct cds_list_head range_to_quark;    /* (range, GQuark) */
 220         GHashTable *quark_to_range_set;         /* (GQuark, range GArray) */
 221 };
 222
 223 struct type_enum {
 224         struct type p;
 225         struct type_integer *integer_type;
 226         struct enum_table table;
 227 };
 228
 229 struct declaration_enum {
 230         struct declaration p;
 231         struct declaration_integer *integer;
 232         struct type_enum *type;
 233         /* Last GQuark values read. Keeping a reference on the GQuark array. */
 234         GArray *value;
 235 };
 236
 237 struct type_string {
 238         struct type p;
 239 };
 240
 241 struct declaration_string {
 242         struct declaration p;
 243         struct type_string *type;
 244         char *value;    /* freed at declaration_string teardown */
 245 };
 246
 247 struct type_field {
 248         GQuark name;
 249         struct type *type;
 250 };
 251
 252 struct field {
 253         GQuark name;
 254         struct declaration *declaration;
 255 };
 256
 257 struct type_struct {
 258         struct type p;
 259         GHashTable *fields_by_name;     /* Tuples (field name, field index) */
 260         struct type_scope *scope;
 261         GArray *fields;                 /* Array of type_field */
 262 };
 263
 264 struct declaration_struct {
 265         struct declaration p;
 266         struct type_struct *type;
 267         struct declaration_scope *scope;
 268         GArray *fields;                 /* Array of struct field */
 269 };
 270
 271 struct type_variant {
 272         struct type p;
 273         GHashTable *fields_by_tag;      /* Tuples (field tag, field index) */
 274         struct type_scope *scope;
 275         GArray *fields;                 /* Array of type_field */
 276 };
 277
 278 struct declaration_variant {
 279         struct declaration p;
 280         struct type_variant *type;
 281         struct declaration_scope *scope;
 282         struct declaration *enum_tag;
 283         GArray *fields;                 /* Array of struct field */
 284         struct field *current_field;    /* Last field read */
 285 };
 286
 287 struct type_array {
 288         struct type p;
 289         size_t len;
 290         struct type *elem;
 291         struct type_scope *scope;
 292 };
 293
 294 struct declaration_array {
 295         struct declaration p;
 296         struct type_array *type;
 297         struct declaration_scope *scope;
 298         struct field current_element;           /* struct field */
 299 };
 300
 301 struct type_sequence {
 302         struct type p;
 303         struct type_integer *len_type;
 304         struct type *elem;
 305         struct type_scope *scope;
 306 };
 307
 308 struct declaration_sequence {
 309         struct declaration p;
 310         struct type_sequence *type;
 311         struct declaration_scope *scope;
 312         struct declaration_integer *len;
 313         struct field current_element;           /* struct field */
 314 };
 315
 316 int register_type(GQuark type_name, struct type *type,
 317                   struct type_scope *scope);
 318 struct type *lookup_type(GQuark type_name, struct type_scope *scope);
 319 struct type_scope *new_type_scope(struct type_scope *parent_scope);
 320 void free_type_scope(struct type_scope *scope);
 321
 322 struct declaration *
 323         lookup_declaration(GQuark field_name, struct declaration_scope *scope);
 324 int register_declaration(GQuark field_name, struct declaration *declaration,
 325                          struct declaration_scope *scope);
 326 struct declaration_scope *
 327         new_declaration_scope(struct declaration_scope *parent_scope);
 328 void free_declaration_scope(struct declaration_scope *scope);
 329
 330 void type_ref(struct type *type);
 331 void type_unref(struct type *type);
 332
 333 void declaration_ref(struct declaration *declaration);
 334 void declaration_unref(struct declaration *declaration);
 335
 336 /* Nameless types can be created by passing a NULL name */
 337
 338 struct type_integer *integer_type_new(const char *name,
 339                                       size_t len, int byte_order,
 340                                       int signedness, size_t alignment);
 341
 342 /*
 343  * mantissa_len is the length of the number of bytes represented by the mantissa
 344  * (e.g. result of DBL_MANT_DIG). It includes the leading 1.
 345  */
 346 struct type_float *float_type_new(const char *name,
 347                                   size_t mantissa_len,
 348                                   size_t exp_len, int byte_order,
 349                                   size_t alignment);
 350
 351 /*
 352  * A GQuark can be translated to/from strings with g_quark_from_string() and
 353  * g_quark_to_string().
 354  */
 355
 356 /*
 357  * Returns a GArray of GQuark or NULL.
 358  * Caller must release the GArray with g_array_unref().
 359  */
 360 GArray *enum_uint_to_quark_set(const struct type_enum *enum_type, uint64_t v);
 361
 362 /*
 363  * Returns a GArray of GQuark or NULL.
 364  * Caller must release the GArray with g_array_unref().
 365  */
 366 GArray *enum_int_to_quark_set(const struct type_enum *enum_type, uint64_t v);
 367
 368 /*
 369  * Returns a GArray of struct enum_range or NULL.
 370  * Callers do _not_ own the returned GArray (and therefore _don't_ need to
 371  * release it).
 372  */
 373 GArray *enum_quark_to_range_set(const struct type_enum *enum_type, GQuark q);
 374 void enum_signed_insert(struct type_enum *enum_type,
 375                         int64_t start, int64_t end, GQuark q);
 376 void enum_unsigned_insert(struct type_enum *enum_type,
 377                           uint64_t start, uint64_t end, GQuark q);
 378 size_t enum_get_nr_enumerators(struct type_enum *enum_type);
 379
 380 struct type_enum *enum_type_new(const char *name,
 381                                 struct type_integer *integer_type);
 382
 383 struct type_struct *struct_type_new(const char *name,
 384                                     struct type_scope *parent_scope);
 385 void struct_type_add_field(struct type_struct *struct_type,
 386                            const char *field_name, struct type *field_type);
 387 /*
 388  * Returns the index of a field within a structure.
 389  */
 390 unsigned long struct_type_lookup_field_index(struct type_struct *struct_type,
 391                                              GQuark field_name);
 392 /*
 393  * field returned only valid as long as the field structure is not appended to.
 394  */
 395 struct type_field *
 396 struct_type_get_field_from_index(struct type_struct *struct_type,
 397                                  unsigned long index);
 398 struct field *
 399 struct_get_field_from_index(struct declaration_struct *struct_declaration,
 400                             unsigned long index);
 401
 402 /*
 403  * The tag enumeration is validated to ensure that it contains only mappings
 404  * from numeric values to a single tag. Overlapping tag value ranges are
 405  * therefore forbidden.
 406  */
 407 struct type_variant *variant_type_new(const char *name,
 408                                       struct type_scope *parent_scope);
 409 void variant_type_add_field(struct type_variant *variant_type,
 410                             const char *tag_name, struct type *tag_type);
 411 struct type_field *
 412 variant_type_get_field_from_tag(struct type_variant *variant_type, GQuark tag);
 413 /*
 414  * Returns 0 on success, -EPERM on error.
 415  */
 416 int variant_declaration_set_tag(struct declaration_variant *variant,
 417                                 struct declaration *enum_tag);
 418 /*
 419  * Returns the field selected by the current tag value.
 420  * field returned only valid as long as the variant structure is not appended
 421  * to.
 422  */
 423 struct field *
 424 variant_get_current_field(struct declaration_variant *variant);
 425
 426 /*
 427  * elem_type passed as parameter now belongs to the array. No need to free it
 428  * explicitly. "len" is the number of elements in the array.
 429  */
 430 struct type_array *array_type_new(const char *name,
 431                                   size_t len, struct type *elem_type,
 432                                   struct type_scope *parent_scope);
 433
 434 /*
 435  * int_type and elem_type passed as parameter now belong to the sequence. No
 436  * need to free them explicitly.
 437  */
 438 struct type_sequence *sequence_type_new(const char *name,
 439                                         struct type_integer *len_type,
 440                                         struct type *elem_type,
 441                                         struct type_scope *parent_scope);
 442
 443 #endif /* _BABELTRACE_TYPES_H */