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 type;
  89
  90 struct type_class {
  91         GQuark name;            /* type name */
  92         size_t alignment;       /* type alignment, in bits */
  93         int ref;                /* number of references to the type class */
  94         /*
  95          * class_free called with type class ref is decremented to 0.
  96          */
  97         void (*class_free)(struct type_class *type_class);
  98         struct type *(*type_new)(struct type_class *_class,
  99                                  struct declaration_scope *parent_scope);
 100         /*
 101          * type_free called with type ref is decremented to 0.
 102          */
 103         void (*type_free)(struct type *type);
 104         /*
 105          * Type copy function. Knows how to find the child type from the parent
 106          * type.
 107          */
 108         void (*copy)(struct stream_pos *dest, const struct format *fdest,
 109                      struct stream_pos *src, const struct format *fsrc,
 110                      struct type *type);
 111 };
 112
 113 struct type {
 114         struct type_class *_class;
 115         int ref;                /* number of references to the type instance */
 116 };
 117
 118 /*
 119  * Because we address in bits, bitfields end up being exactly the same as
 120  * integers, except that their read/write functions must be able to deal with
 121  * read/write non aligned on CHAR_BIT.
 122  */
 123 struct type_class_integer {
 124         struct type_class p;
 125         size_t len;             /* length, in bits. */
 126         int byte_order;         /* byte order */
 127         int signedness;
 128 };
 129
 130 struct type_integer {
 131         struct type p;
 132         struct type_class_integer *_class;
 133         /* Last values read */
 134         union {
 135                 uint64_t _unsigned;
 136                 int64_t _signed;
 137         } value;
 138 };
 139
 140 struct type_class_float {
 141         struct type_class p;
 142         struct type_class_integer *sign;
 143         struct type_class_integer *mantissa;
 144         struct type_class_integer *exp;
 145         int byte_order;
 146         /* TODO: we might want to express more info about NaN, +inf and -inf */
 147 };
 148
 149 struct type_float {
 150         struct type p;
 151         struct type_class_float *_class;
 152         /* Last values read */
 153         long double value;
 154 };
 155
 156 /*
 157  * enum_val_equal assumes that signed and unsigned memory layout overlap.
 158  */
 159 struct enum_range {
 160         union {
 161                 int64_t _signed;
 162                 uint64_t _unsigned;
 163         } start;        /* lowest range value */
 164         union {
 165                 int64_t _signed;
 166                 uint64_t _unsigned;
 167         } end;          /* highest range value */
 168 };
 169
 170 struct enum_range_to_quark {
 171         struct cds_list_head node;
 172         struct enum_range range;
 173         GQuark quark;
 174 };
 175
 176 /*
 177  * We optimize the common case (range of size 1: single value) by creating a
 178  * hash table mapping values to quark sets. We then lookup the ranges to
 179  * complete the quark set.
 180  *
 181  * TODO: The proper structure to hold the range to quark set mapping would be an
 182  * interval tree, with O(n) size, O(n*log(n)) build time and O(log(n)) query
 183  * time. Using a simple O(n) list search for now for implementation speed and
 184  * given that we can expect to have a _relatively_ small number of enumeration
 185  * ranges. This might become untrue if we are fed with symbol tables often
 186  * required to lookup function names from instruction pointer value.
 187  */
 188 struct enum_table {
 189         GHashTable *value_to_quark_set;         /* (value, GQuark GArray) */
 190         struct cds_list_head range_to_quark;    /* (range, GQuark) */
 191         GHashTable *quark_to_range_set;         /* (GQuark, range GArray) */
 192 };
 193
 194 struct type_class_enum {
 195         struct type_class_integer p;    /* inherit from integer */
 196         struct enum_table table;
 197 };
 198
 199 struct type_enum {
 200         struct type p;
 201         struct type_class_enum *_class;
 202         /* Last GQuark values read. Keeping a reference on the GQuark array. */
 203         GArray *value;
 204 };
 205
 206 struct type_class_string {
 207         struct type_class p;
 208 };
 209
 210 struct type_string {
 211         struct type p;
 212         struct type_class_string *_class;
 213         char *value;    /* freed at type_string teardown */
 214 };
 215
 216 struct type_class_field {
 217         GQuark name;
 218         struct type_class *type_class;
 219 };
 220
 221 struct field {
 222         struct type *type;
 223 };
 224
 225 struct type_class_struct {
 226         struct type_class p;
 227         GHashTable *fields_by_name;     /* Tuples (field name, field index) */
 228         GArray *fields;                 /* Array of type_class_field */
 229 };
 230
 231 struct type_struct {
 232         struct type p;
 233         struct type_class_struct *_class;
 234         struct declaration_scope *scope;
 235         GArray *fields;                 /* Array of struct field */
 236 };
 237
 238 struct type_class_variant {
 239         struct type_class p;
 240         GHashTable *fields_by_tag;      /* Tuples (field tag, field index) */
 241         GArray *fields;                 /* Array of type_class_field */
 242 };
 243
 244 struct type_variant {
 245         struct type p;
 246         struct type_class_variant *_class;
 247         struct declaration_scope *scope;
 248         struct type *tag;
 249         GArray *fields;                 /* Array of struct field */
 250         struct field *current_field;    /* Last field read */
 251 };
 252
 253 struct type_class_array {
 254         struct type_class p;
 255         size_t len;
 256         struct type_class *elem;
 257 };
 258
 259 struct type_array {
 260         struct type p;
 261         struct type_class_array *_class;
 262         struct declaration_scope *scope;
 263         struct field current_element;           /* struct field */
 264 };
 265
 266 struct type_class_sequence {
 267         struct type_class p;
 268         struct type_class_integer *len_class;
 269         struct type_class *elem;
 270 };
 271
 272 struct type_sequence {
 273         struct type p;
 274         struct type_class_sequence *_class;
 275         struct declaration_scope *scope;
 276         struct type_integer *len;
 277         struct field current_element;           /* struct field */
 278 };
 279
 280 /* Type declaration scope */
 281 struct declaration_scope {
 282         /* Hash table mapping type name GQuark to struct type_class */
 283         GHashTable *type_classes;
 284         struct declaration_scope *parent_scope;
 285 };
 286
 287 struct type_class *lookup_type_class(GQuark qname,
 288                                      struct declaration_scope *scope);
 289 int register_type_class(struct type_class *type_class,
 290                         struct declaration_scope *scope);
 291
 292 void type_class_ref(struct type_class *type_class);
 293 void type_class_unref(struct type_class *type_class);
 294
 295 struct declaration_scope *
 296 new_declaration_scope(struct declaration_scope *parent_scope);
 297 void free_declaration_scope(struct declaration_scope *scope);
 298
 299 void type_ref(struct type *type);
 300 void type_unref(struct type *type);
 301
 302 /* Nameless types can be created by passing a NULL name */
 303
 304 struct type_class_integer *integer_type_class_new(const char *name,
 305                                             size_t len, int byte_order,
 306                                             int signedness,
 307                                             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_class_float *float_type_class_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_class_enum *enum_class,
 328                                uint64_t v);
 329
 330 /*
 331  * Returns a GArray of GQuark or NULL.
 332  * Caller must release the GArray with g_array_unref().
 333  */
 334 GArray *enum_int_to_quark_set(const struct type_class_enum *enum_class,
 335                               uint64_t v);
 336
 337 /*
 338  * Returns a GArray of struct enum_range or NULL.
 339  * Callers do _not_ own the returned GArray (and therefore _don't_ need to
 340  * release it).
 341  */
 342 GArray *enum_quark_to_range_set(const struct type_class_enum *enum_class,
 343                                 GQuark q);
 344 void enum_signed_insert(struct type_class_enum *enum_class,
 345                         int64_t start, int64_t end, GQuark q);
 346 void enum_unsigned_insert(struct type_class_enum *enum_class,
 347                           uint64_t start, uint64_t end, GQuark q);
 348 size_t enum_get_nr_enumerators(struct type_class_enum *enum_class);
 349
 350 struct type_class_enum *enum_type_class_new(const char *name,
 351                                       size_t len, int byte_order,
 352                                       int signedness,
 353                                       size_t alignment);
 354
 355 struct type_class_struct *struct_type_class_new(const char *name);
 356 void struct_type_class_add_field(struct type_class_struct *struct_class,
 357                                  const char *field_name,
 358                                  struct type_class *type_class);
 359 /*
 360  * Returns the index of a field within a structure.
 361  */
 362 unsigned long
 363 struct_type_class_lookup_field_index(struct type_class_struct *struct_class,
 364                                      GQuark field_name);
 365 /*
 366  * field returned only valid as long as the field structure is not appended to.
 367  */
 368 struct type_class_field *
 369 struct_type_class_get_field_from_index(struct type_class_struct *struct_class,
 370                                        unsigned long index);
 371 struct field *
 372 struct_type_get_field_from_index(struct type_struct *_struct,
 373                                  unsigned long index);
 374
 375 /*
 376  * The tag enumeration is validated to ensure that it contains only mappings
 377  * from numeric values to a single tag. Overlapping tag value ranges are
 378  * therefore forbidden.
 379  */
 380 struct type_class_variant *variant_type_class_new(const char *name);
 381 void variant_type_class_add_field(struct type_class_variant *variant_class,
 382                                   const char *tag_name,
 383                                   struct type_class *type_class);
 384 struct type_class_field *
 385 variant_type_class_get_field_from_tag(struct type_class_variant *variant_class,
 386                                       GQuark tag);
 387 /*
 388  * Returns 0 on success, -EPERM on error.
 389  */
 390 int variant_type_set_tag(struct type_variant *variant,
 391                          struct type *enum_tag_instance);
 392 /*
 393  * Returns the field selected by the current tag value.
 394  * field returned only valid as long as the variant structure is not appended
 395  * to.
 396  */
 397 struct field *
 398 variant_type_get_current_field(struct type_variant *variant);
 399
 400 /*
 401  * elem_class passed as parameter now belongs to the array. No need to free it
 402  * explicitly. "len" is the number of elements in the array.
 403  */
 404 struct type_class_array *array_type_class_new(const char *name,
 405                                         size_t len,
 406                                         struct type_class *elem_class);
 407
 408 /*
 409  * int_class and elem_class passed as parameter now belongs to the sequence. No
 410  * need to free them explicitly.
 411  */
 412 struct type_class_sequence *sequence_type_class_new(const char *name,
 413                                         struct type_class_integer *len_class,
 414                                         struct type_class *elem_class);
 415
 416 #endif /* _BABELTRACE_TYPES_H */