gcc/ctfc.h

   1 /* ctfc.h - Declarations and definitions related to the CTF container.
   2    Copyright (C) 2019,2021 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 /* This file defines the data structures and functions used by the compiler
  21    to generate the CTF debug info.  The definitions below are compiler internal
  22    representations and closely reflect the CTF format requirements in <ctf.h>.
  23
  24    The contents of the CTF container are used eventually for emission of both
  25    CTF (ctfout.c) and BTF debug info (btfout.c), as the two type debug formats
  26    are close cousins.  */
  27
  28 #ifndef GCC_CTFC_H
  29 #define GCC_CTFC_H 1
  30
  31 #include "config.h"
  32 #include "system.h"
  33 #include "tree.h"
  34 #include "fold-const.h"
  35 #include "dwarf2ctf.h"
  36 #include "ctf.h"
  37 #include "btf.h"
  38
  39 /* Invalid CTF type ID definition.  */
  40
  41 #define CTF_NULL_TYPEID 0
  42
  43 /* Value to start generating the CTF type ID from.  */
  44
  45 #define CTF_INIT_TYPEID 1
  46
  47 /* CTF type ID.  */
  48
  49 typedef uint64_t ctf_id_t;
  50
  51 /* CTF string table element (list node).  */
  52
  53 typedef struct GTY ((chain_next ("%h.cts_next"))) ctf_string
  54 {
  55   const char * cts_str;           /* CTF string.  */
  56   struct ctf_string * cts_next;   /* A list node.  */
  57 } ctf_string_t;
  58
  59 /* Internal representation of CTF string table.  */
  60
  61 typedef struct GTY (()) ctf_strtable
  62 {
  63   ctf_string_t * ctstab_head;       /* Head str ptr.  */
  64   ctf_string_t * ctstab_tail;       /* Tail.  new str appended to tail.  */
  65   int ctstab_num;                   /* Number of strings in the table.  */
  66   size_t ctstab_len;                /* Size of string table in bytes.  */
  67   const char * ctstab_estr;         /* Empty string "".  */
  68 } ctf_strtable_t;
  69
  70 /* Encoding information for integers, floating-point values etc.  The flags
  71    field will contain values appropriate for the type defined in <ctf.h>.  */
  72
  73 typedef struct GTY (()) ctf_encoding
  74 {
  75   unsigned int cte_format;  /* Data format (CTF_INT_* or CTF_FP_* flags).  */
  76   unsigned int cte_offset;  /* Offset of value in bits.  */
  77   unsigned int cte_bits;    /* Size of storage in bits.  */
  78 } ctf_encoding_t;
  79
  80 /* Array information for CTF generation.  */
  81
  82 typedef struct GTY (()) ctf_arinfo
  83 {
  84   ctf_id_t ctr_contents;        /* Type of array contents.  */
  85   ctf_id_t ctr_index;           /* Type of array index.  */
  86   unsigned int ctr_nelems;      /* Number of elements.  */
  87 } ctf_arinfo_t;
  88
  89 /* Function information for CTF generation.  */
  90
  91 typedef struct GTY (()) ctf_funcinfo
  92 {
  93   ctf_id_t ctc_return;          /* Function return type.  */
  94   unsigned int ctc_argc;        /* Number of typed arguments to function.  */
  95   unsigned int ctc_flags;       /* Function attributes (see below).  */
  96 } ctf_funcinfo_t;
  97
  98 typedef struct GTY (()) ctf_sliceinfo
  99 {
 100   unsigned int cts_type;        /* Reference CTF type.  */
 101   unsigned short cts_offset;    /* Offset in bits of the first bit.  */
 102   unsigned short cts_bits;      /* Size in bits.  */
 103 } ctf_sliceinfo_t;
 104
 105 /* CTF type representation internal to the compiler.  It closely reflects the
 106    ctf_type_t type node in <ctf.h> except the GTY (()) tags.  */
 107
 108 typedef struct GTY (()) ctf_itype
 109 {
 110   uint32_t ctti_name;           /* Reference to name in string table.  */
 111   uint32_t ctti_info;           /* Encoded kind, variant length (see below).  */
 112   union GTY ((desc ("0")))
 113   {
 114     uint32_t GTY ((tag ("0"))) _size;/* Size of entire type in bytes.  */
 115     uint32_t GTY ((tag ("1"))) _type;/* Reference to another type.  */
 116   } _u;
 117   uint32_t ctti_lsizehi;        /* High 32 bits of type size in bytes.  */
 118   uint32_t ctti_lsizelo;        /* Low 32 bits of type size in bytes.  */
 119 } ctf_itype_t;
 120
 121 #define ctti_size _u._size
 122 #define ctti_type _u._type
 123
 124 /* Function arguments end with varargs.  */
 125
 126 #define CTF_FUNC_VARARG 0x1
 127
 128 /* Struct/union/enum member definition for CTF generation.  */
 129
 130 typedef struct GTY ((chain_next ("%h.dmd_next"))) ctf_dmdef
 131 {
 132   const char * dmd_name;        /* Name of this member.  */
 133   ctf_id_t dmd_type;            /* Type of this member (for sou).  */
 134   uint32_t dmd_name_offset;     /* Offset of the name in str table.  */
 135   uint64_t dmd_offset;          /* Offset of this member in bits (for sou).  */
 136   int dmd_value;                /* Value of this member (for enum).  */
 137   struct ctf_dmdef * dmd_next;  /* A list node.  */
 138 } ctf_dmdef_t;
 139
 140 #define ctf_dmd_list_next(elem) ((ctf_dmdef_t *)((elem)->dmd_next))
 141
 142 /* Function Argument.  */
 143
 144 typedef struct GTY (()) ctf_func_arg
 145 {
 146   ctf_id_t farg_type;             /* Type identifier of the argument.  */
 147   const char * farg_name;         /* Name of the the argument.  */
 148   uint32_t farg_name_offset;      /* Offset of the name in str table.  */
 149   struct ctf_func_arg * farg_next;/* A list node.  */
 150 } ctf_func_arg_t;
 151
 152 #define ctf_farg_list_next(elem) ((ctf_func_arg_t *)((elem)->farg_next))
 153
 154 /* Type definition for CTF generation.  */
 155
 156 struct GTY ((for_user)) ctf_dtdef
 157 {
 158   dw_die_ref dtd_key;         /* Type key for hashing.  */
 159   const char * dtd_name;      /* Name associated with definition (if any).  */
 160   ctf_id_t dtd_type;          /* Type identifier for this definition.  */
 161   ctf_itype_t dtd_data;       /* Type node.  */
 162   bool from_global_func; /* Whether this type was added from a global
 163                             function.  */
 164   union GTY ((desc ("ctf_dtu_d_union_selector (&%1)")))
 165   {
 166     /* struct, union, or enum.  */
 167     ctf_dmdef_t * GTY ((tag ("CTF_DTU_D_MEMBERS"))) dtu_members;
 168     /* array.  */
 169     ctf_arinfo_t GTY ((tag ("CTF_DTU_D_ARRAY"))) dtu_arr;
 170     /* integer or float.  */
 171     ctf_encoding_t GTY ((tag ("CTF_DTU_D_ENCODING"))) dtu_enc;
 172     /* function.  */
 173     ctf_func_arg_t * GTY ((tag ("CTF_DTU_D_ARGUMENTS"))) dtu_argv;
 174     /* slice.  */
 175     ctf_sliceinfo_t GTY ((tag ("CTF_DTU_D_SLICE"))) dtu_slice;
 176   } dtd_u;
 177 };
 178
 179 typedef struct ctf_dtdef ctf_dtdef_t;
 180
 181 /* Variable definition for CTF generation.  */
 182
 183 struct GTY ((for_user)) ctf_dvdef
 184 {
 185   dw_die_ref dvd_key;           /* DWARF DIE corresponding to the variable.  */
 186   const char * dvd_name;        /* Name associated with variable.  */
 187   uint32_t dvd_name_offset;     /* Offset of the name in str table.  */
 188   unsigned int dvd_visibility;  /* External visibility.  0=static,1=global.  */
 189   ctf_id_t dvd_type;            /* Type of variable.  */
 190 };
 191
 192 typedef struct ctf_dvdef ctf_dvdef_t;
 193
 194 typedef ctf_dvdef_t * ctf_dvdef_ref;
 195 typedef ctf_dtdef_t * ctf_dtdef_ref;
 196
 197 /* Location information for CTF Types and CTF Variables.  */
 198
 199 typedef struct GTY (()) ctf_srcloc
 200 {
 201   const char * ctsloc_file;
 202   unsigned int ctsloc_line;
 203   unsigned int ctsloc_col;
 204 } ctf_srcloc_t;
 205
 206 typedef ctf_srcloc_t * ctf_srcloc_ref;
 207
 208 /* Helper enum and api for the GTY machinery to work on union dtu_d.  */
 209
 210 enum ctf_dtu_d_union_enum {
 211   CTF_DTU_D_MEMBERS,
 212   CTF_DTU_D_ARRAY,
 213   CTF_DTU_D_ENCODING,
 214   CTF_DTU_D_ARGUMENTS,
 215   CTF_DTU_D_SLICE,
 216 };
 217
 218 enum ctf_dtu_d_union_enum
 219 ctf_dtu_d_union_selector (ctf_dtdef_ref);
 220
 221 struct ctfc_dtd_hasher : ggc_ptr_hash <ctf_dtdef_t>
 222 {
 223   typedef ctf_dtdef_ref compare_type;
 224
 225   static hashval_t hash (ctf_dtdef_ref);
 226   static bool equal (ctf_dtdef_ref, ctf_dtdef_ref);
 227 };
 228
 229 inline hashval_t
 230 ctfc_dtd_hasher::hash (ctf_dtdef_ref dtd)
 231 {
 232   return htab_hash_pointer (dtd->dtd_key);
 233 }
 234
 235 inline bool
 236 ctfc_dtd_hasher::equal (ctf_dtdef_ref dtd, ctf_dtdef_ref dtd2)
 237 {
 238   return (dtd->dtd_key == dtd2->dtd_key);
 239 }
 240
 241 struct ctfc_dvd_hasher : ggc_ptr_hash <ctf_dvdef_t>
 242 {
 243   typedef ctf_dvdef_ref compare_type;
 244
 245   static hashval_t hash (ctf_dvdef_ref);
 246   static bool equal (ctf_dvdef_ref, ctf_dvdef_ref);
 247 };
 248
 249 inline hashval_t
 250 ctfc_dvd_hasher::hash (ctf_dvdef_ref dvd)
 251 {
 252   return htab_hash_pointer (dvd->dvd_key);
 253 }
 254
 255 inline bool
 256 ctfc_dvd_hasher::equal (ctf_dvdef_ref dvd, ctf_dvdef_ref dvd2)
 257 {
 258   return (dvd->dvd_key == dvd2->dvd_key);
 259 }
 260
 261 /* CTF container structure.
 262    It is the context passed around when generating ctf debug info.  There is
 263    one container per translation unit.  */
 264
 265 typedef struct GTY (()) ctf_container
 266 {
 267   /* CTF Preamble.  */
 268   unsigned short ctfc_magic;
 269   unsigned char ctfc_version;
 270   unsigned char ctfc_flags;
 271   uint32_t ctfc_cuname_offset;
 272
 273   /* CTF types.  */
 274   hash_table <ctfc_dtd_hasher> * GTY (()) ctfc_types;
 275   /* CTF variables.  */
 276   hash_table <ctfc_dvd_hasher> * GTY (()) ctfc_vars;
 277
 278   /* CTF string table.  */
 279   ctf_strtable_t ctfc_strtable;
 280   /* Auxilliary string table.  At this time, used for keeping func arg names
 281      for BTF.  */
 282   ctf_strtable_t ctfc_aux_strtable;
 283
 284   uint64_t ctfc_num_types;
 285   uint64_t ctfc_num_stypes;
 286   uint64_t ctfc_num_global_funcs;
 287   uint64_t ctfc_num_global_objts;
 288
 289   /* Number of vlen bytes - the variable length portion after ctf_type_t and
 290      ctf_stype_t in the CTF section.  This is used to calculate the offsets in
 291      the CTF header.  */
 292   uint64_t ctfc_num_vlen_bytes;
 293
 294   /* Next CTF type id to assign.  */
 295   ctf_id_t ctfc_nextid;
 296
 297   /* Specify an explicit length of 0 so that the GC marking routines steer
 298      clear of marking the CTF vars and CTF types twice. These lists below do
 299      not own the pointed to objects, they simply hold references to them.  */
 300
 301   /* List of pre-processed CTF Variables.  CTF requires that the variables
 302      appear in the sorted order of their names.  */
 303   ctf_dvdef_t ** GTY ((length ("0"))) ctfc_vars_list;
 304   /* List of pre-processed CTF types.  CTF requires that a shared type must
 305      appear before the type that uses it.  For the compiler, this means types
 306      are emitted in sorted order of their type IDs.  */
 307   ctf_dtdef_t ** GTY ((length ("0"))) ctfc_types_list;
 308   /* List of CTF function types for global functions.  The order of global
 309      function entries in the CTF funcinfo section is undefined by the
 310      compiler.  */
 311   ctf_dtdef_t ** GTY ((length ("0"))) ctfc_gfuncs_list;
 312   /* List of CTF variables at global scope.  The order of global object entries
 313      in the CTF objinfo section is undefined by the  compiler.  */
 314   ctf_dvdef_t ** GTY ((length ("0"))) ctfc_gobjts_list;
 315
 316   /* Following members are for debugging only.  They do not add functional
 317      value to the task of CTF creation.  These can be cleaned up once CTF
 318      generation stabilizes.  */
 319
 320   /* Keep a count of the number of bytes dumped in asm for debugging
 321      purposes.  */
 322   uint64_t ctfc_numbytes_asm;
 323    /* Total length of all strings in CTF.  */
 324   size_t ctfc_strlen;
 325   /* Total length of all strings in aux string table.  */
 326   size_t ctfc_aux_strlen;
 327
 328 } ctf_container_t;
 329
 330 /* Markers for which string table from the CTF container to use.  */
 331
 332 #define CTF_STRTAB 0        /* CTF string table.  */
 333 #define CTF_AUX_STRTAB 1    /* CTF auxilliary string table.  */
 334
 335 typedef ctf_container_t * ctf_container_ref;
 336
 337 extern GTY (()) ctf_container_ref tu_ctfc;
 338
 339 extern void ctfc_delete_container (ctf_container_ref);
 340
 341 /* If the next ctf type id is still set to the init value, no ctf records to
 342    report.  */
 343 extern bool ctfc_is_empty_container (ctf_container_ref);
 344
 345 /* Get the total number of CTF types in the container.  */
 346
 347 extern unsigned int ctfc_get_num_ctf_types (ctf_container_ref);
 348
 349 /* Get the total number of CTF variables in the container.  */
 350
 351 extern unsigned int ctfc_get_num_ctf_vars (ctf_container_ref);
 352
 353 /* Get reference to the CTF string table or the CTF auxilliary
 354    string table.  */
 355
 356 extern ctf_strtable_t * ctfc_get_strtab (ctf_container_ref, int);
 357
 358 /* Get the length of the specified string table in the CTF container.  */
 359
 360 extern size_t ctfc_get_strtab_len (ctf_container_ref, int);
 361
 362 /* Get the number of bytes to represent the variable length portion of all CTF
 363    types in the CTF container.  */
 364
 365 extern size_t ctfc_get_num_vlen_bytes (ctf_container_ref);
 366
 367 /* The compiler demarcates whether types are visible at top-level scope or not.
 368    The only example so far of a type not visible at top-level scope is slices.
 369    CTF_ADD_NONROOT is used to indicate the latter.  */
 370 #define CTF_ADD_NONROOT 0       /* CTF type only visible in nested scope.  */
 371 #define CTF_ADD_ROOT    1       /* CTF type visible at top-level scope.  */
 372
 373 /* These APIs allow to initialize and finalize the CTF machinery and
 374    to add types to the CTF container associated to the current
 375    translation unit.  Used in dwarf2ctf.c.  */
 376
 377 extern void ctf_init (void);
 378 extern void ctf_output (const char * filename);
 379 extern void ctf_finalize (void);
 380
 381 extern void btf_output (const char * filename);
 382 extern void btf_init_postprocess (void);
 383 extern void btf_finalize (void);
 384
 385 extern ctf_container_ref ctf_get_tu_ctfc (void);
 386
 387 extern bool ctf_type_exists (ctf_container_ref, dw_die_ref, ctf_id_t *);
 388
 389 extern void ctf_add_cuname (ctf_container_ref, const char *);
 390
 391 extern ctf_dtdef_ref ctf_dtd_lookup (const ctf_container_ref ctfc,
 392                                      dw_die_ref die);
 393 extern ctf_dvdef_ref ctf_dvd_lookup (const ctf_container_ref ctfc,
 394                                      dw_die_ref die);
 395
 396 extern const char * ctf_add_string (ctf_container_ref, const char *,
 397                                     uint32_t *, int);
 398
 399 extern ctf_id_t ctf_add_reftype (ctf_container_ref, uint32_t, ctf_id_t,
 400                                  uint32_t, dw_die_ref);
 401 extern ctf_id_t ctf_add_enum (ctf_container_ref, uint32_t, const char *,
 402                               HOST_WIDE_INT, dw_die_ref);
 403 extern ctf_id_t ctf_add_slice (ctf_container_ref, uint32_t, ctf_id_t,
 404                                uint32_t, uint32_t, dw_die_ref);
 405 extern ctf_id_t ctf_add_float (ctf_container_ref, uint32_t, const char *,
 406                                const ctf_encoding_t *, dw_die_ref);
 407 extern ctf_id_t ctf_add_integer (ctf_container_ref, uint32_t, const char *,
 408                                  const ctf_encoding_t *, dw_die_ref);
 409 extern ctf_id_t ctf_add_unknown (ctf_container_ref, uint32_t, const char *,
 410                                  const ctf_encoding_t *, dw_die_ref);
 411 extern ctf_id_t ctf_add_pointer (ctf_container_ref, uint32_t, ctf_id_t,
 412                                  dw_die_ref);
 413 extern ctf_id_t ctf_add_array (ctf_container_ref, uint32_t,
 414                                const ctf_arinfo_t *, dw_die_ref);
 415 extern ctf_id_t ctf_add_forward (ctf_container_ref, uint32_t, const char *,
 416                                  uint32_t, dw_die_ref);
 417 extern ctf_id_t ctf_add_typedef (ctf_container_ref, uint32_t, const char *,
 418                                  ctf_id_t, dw_die_ref);
 419 extern ctf_id_t ctf_add_function (ctf_container_ref, uint32_t, const char *,
 420                                   const ctf_funcinfo_t *, dw_die_ref, bool);
 421 extern ctf_id_t ctf_add_sou (ctf_container_ref, uint32_t, const char *,
 422                              uint32_t, size_t, dw_die_ref);
 423
 424 extern int ctf_add_enumerator (ctf_container_ref, ctf_id_t, const char *,
 425                                HOST_WIDE_INT, dw_die_ref);
 426 extern int ctf_add_member_offset (ctf_container_ref, dw_die_ref, const char *,
 427                                   ctf_id_t, uint64_t);
 428 extern int ctf_add_function_arg (ctf_container_ref, dw_die_ref,
 429                                  const char *, ctf_id_t);
 430 extern int ctf_add_variable (ctf_container_ref, const char *, ctf_id_t,
 431                              dw_die_ref, unsigned int);
 432
 433 extern ctf_id_t ctf_lookup_tree_type (ctf_container_ref, const tree);
 434 extern ctf_id_t get_btf_id (ctf_id_t);
 435
 436 /* CTF section does not emit location information; at this time, location
 437    information is needed for BTF CO-RE use-cases.  */
 438
 439 extern int ctfc_get_dtd_srcloc (ctf_dtdef_ref, ctf_srcloc_ref);
 440 extern int ctfc_get_dvd_srcloc (ctf_dvdef_ref, ctf_srcloc_ref);
 441
 442 #endif /* GCC_CTFC_H */