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