gcc/gengtype.h

   1 /* Process source files and output type information.
   2    Copyright (C) 2002-2020 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 #ifndef GCC_GENGTYPE_H
  21 #define GCC_GENGTYPE_H
  22
  23 #define obstack_chunk_alloc    xmalloc
  24 #define obstack_chunk_free     free
  25 #define OBSTACK_CHUNK_SIZE     0
  26
  27 /* Sets of accepted source languages like C, C++, Ada... are
  28    represented by a bitmap.  */
  29 typedef unsigned lang_bitmap;
  30
  31 /* Variable length structure representing an input file.  A hash table
  32    ensure uniqueness for a given input file name.  The only function
  33    allocating input_file-s is input_file_by_name.  */
  34 struct input_file_st
  35 {
  36   struct outf* inpoutf;  /* Cached corresponding output file, computed
  37                             in get_output_file_with_visibility.  */
  38   lang_bitmap inpbitmap; /* The set of languages using this file.  */
  39   bool inpisplugin;      /* Flag set for plugin input files.  */
  40   char inpname[1];       /* A variable-length array, ended by a null
  41                             char.  */
  42 };
  43 typedef struct input_file_st input_file;
  44
  45 /* A file position, mostly for error messages.
  46    The FILE element may be compared using pointer equality.  */
  47 struct fileloc
  48 {
  49   const input_file *file;
  50   int line;
  51 };
  52
  53
  54 /* Table of all input files and its size.  */
  55 extern const input_file** gt_files;
  56 extern size_t num_gt_files;
  57
  58 /* A number of places use the name of this "gengtype.c" file for a
  59    location for things that we can't rely on the source to define.  We
  60    also need to refer to the "system.h" file specifically.  These two
  61    pointers are initialized early in main.  */
  62 extern input_file* this_file;
  63 extern input_file* system_h_file;
  64
  65 /* Retrieve or create the input_file for a given name, which is a file
  66    path.  This is the only function allocating input_file-s and it is
  67    hash-consing them.  */
  68 input_file* input_file_by_name (const char* name);
  69
  70 /* For F an input_file, return the relative path to F from $(srcdir)
  71    if the latter is a prefix in F, NULL otherwise.  */
  72 const char *get_file_srcdir_relative_path (const input_file *inpf);
  73
  74 /* Get the name of an input file.  */
  75 static inline const char*
  76 get_input_file_name (const input_file *inpf)
  77 {
  78   if (inpf)
  79       return inpf->inpname;
  80   return NULL;
  81 }
  82
  83 /* Return a bitmap which has bit `1 << BASE_FILE_<lang>' set iff
  84    INPUT_FILE is used by <lang>.
  85
  86    This function should be written to assume that a file _is_ used
  87    if the situation is unclear.  If it wrongly assumes a file _is_ used,
  88    a linker error will result.  If it wrongly assumes a file _is not_ used,
  89    some GC roots may be missed, which is a much harder-to-debug problem.
  90   */
  91
  92 static inline lang_bitmap
  93 get_lang_bitmap (const input_file* inpf)
  94 {
  95   if (inpf == NULL)
  96     return 0;
  97   return inpf->inpbitmap;
  98 }
  99
 100 /* Set the bitmap returned by get_lang_bitmap.  The only legitimate
 101    callers of this function are read_input_list & read_state_*.  */
 102 static inline void
 103 set_lang_bitmap (input_file* inpf, lang_bitmap n)
 104 {
 105   gcc_assert (inpf);
 106   inpf->inpbitmap = n;
 107 }
 108
 109 /* Vector of per-language directories.  */
 110 extern const char **lang_dir_names;
 111 extern size_t num_lang_dirs;
 112
 113 /* Data types handed around within, but opaque to, the lexer and parser.  */
 114 typedef struct pair *pair_p;
 115 typedef struct type *type_p;
 116 typedef const struct type *const_type_p;
 117 typedef struct options *options_p;
 118
 119 /* Variables used to communicate between the lexer and the parser.  */
 120 extern int lexer_toplevel_done;
 121 extern struct fileloc lexer_line;
 122
 123 /* Various things, organized as linked lists, needed both in
 124    gengtype.c & in gengtype-state.c files.  */
 125 extern pair_p typedefs;
 126 extern type_p structures;
 127 extern pair_p variables;
 128
 129 /* An enum for distinguishing GGC vs PCH.  */
 130
 131 enum write_types_kinds
 132 {
 133   WTK_GGC,
 134   WTK_PCH,
 135
 136   NUM_WTK
 137 };
 138
 139 /* Discrimating kind of types we can understand.  */
 140
 141 enum typekind {
 142   TYPE_NONE=0,          /* Never used, so zeroed memory is invalid.  */
 143   TYPE_UNDEFINED,       /* We have not yet seen a definition for this type.
 144                            If a type is still undefined when generating code,
 145                            an error will be generated.  */
 146   TYPE_SCALAR,          /* Scalar types like char.  */
 147   TYPE_STRING,          /* The string type.  */
 148   TYPE_STRUCT,          /* Type for GTY-ed structs.  */
 149   TYPE_UNION,           /* Type for GTY-ed discriminated unions.  */
 150   TYPE_POINTER,         /* Pointer type to GTY-ed type.  */
 151   TYPE_ARRAY,           /* Array of GTY-ed types.  */
 152   TYPE_LANG_STRUCT,     /* GCC front-end language specific structs.
 153                            Various languages may have homonymous but
 154                            different structs.  */
 155   TYPE_USER_STRUCT      /* User defined type.  Walkers and markers for
 156                            this type are assumed to be provided by the
 157                            user.  */
 158 };
 159
 160 /* Discriminating kind for options.  */
 161 enum option_kind {
 162   OPTION_NONE=0,        /* Never used, so zeroed memory is invalid.  */
 163   OPTION_STRING,        /* A string-valued option.  Most options are
 164                            strings.  */
 165   OPTION_TYPE,          /* A type-valued option.  */
 166   OPTION_NESTED         /* Option data for 'nested_ptr'.  */
 167 };
 168
 169
 170 /* A way to pass data through to the output end.  */
 171 struct options {
 172   struct options *next;         /* next option of the same pair.  */
 173   const char *name;             /* GTY option name.  */
 174   enum option_kind kind;        /* discriminating option kind.  */
 175   union {
 176     const char* string;                    /* When OPTION_STRING.  */
 177     type_p type;                           /* When OPTION_TYPE.  */
 178     struct nested_ptr_data* nested;        /* when OPTION_NESTED.  */
 179   } info;
 180 };
 181
 182
 183 /* Option data for the 'nested_ptr' option.  */
 184 struct nested_ptr_data {
 185   type_p type;
 186   const char *convert_to;
 187   const char *convert_from;
 188 };
 189
 190 /* Some functions to create various options structures with name NAME
 191    and info INFO.  NEXT is the next option in the chain.  */
 192
 193 /* Create a string option.  */
 194 options_p create_string_option (options_p next, const char* name,
 195                                 const char* info);
 196
 197 /* Create a type option.  */
 198 options_p create_type_option (options_p next, const char* name,
 199                               type_p info);
 200
 201 /* Create a nested option.  */
 202 options_p create_nested_option (options_p next, const char* name,
 203                                 struct nested_ptr_data* info);
 204
 205 /* Create a nested pointer option.  */
 206 options_p create_nested_ptr_option (options_p next, type_p t,
 207                                     const char *to, const char *from);
 208
 209 /* A name and a type.  */
 210 struct pair {
 211   pair_p next;                  /* The next pair in the linked list.  */
 212   const char *name;             /* The defined name.  */
 213   type_p type;                  /* Its GTY-ed type.  */
 214   struct fileloc line;          /* The file location.  */
 215   options_p opt;                /* GTY options, as a linked list.  */
 216 };
 217
 218 /* Usage information for GTY-ed types.  Gengtype has to care only of
 219    used GTY-ed types.  Types are initially unused, and their usage is
 220    computed by set_gc_used_type and set_gc_used functions.  */
 221
 222 enum gc_used_enum {
 223
 224   /* We need that zeroed types are initially unused.  */
 225   GC_UNUSED=0,
 226
 227   /* The GTY-ed type is used, e.g by a GTY-ed variable or a field
 228      inside a GTY-ed used type.  */
 229   GC_USED,
 230
 231   /* For GTY-ed structures whose definitions we haven't seen so far
 232      when we encounter a pointer to it that is annotated with
 233      ``maybe_undef''.  If after reading in everything we don't have
 234      source file information for it, we assume that it never has been
 235      defined.  */
 236   GC_MAYBE_POINTED_TO,
 237
 238   /* For known GTY-ed structures which are pointed to by GTY-ed
 239      variables or fields.  */
 240   GC_POINTED_TO
 241 };
 242
 243 /* Our type structure describes all types handled by gengtype.  */
 244 struct type {
 245   /* Discriminating kind, cannot be TYPE_NONE.  */
 246   enum typekind kind;
 247
 248   /* For top-level structs or unions, the 'next' field links the
 249      global list 'structures'; for lang_structs, their homonymous structs are
 250      linked using this 'next' field.  The homonymous list starts at the
 251      s.lang_struct field of the lang_struct.  See the new_structure function
 252      for details.  This is tricky!  */
 253   type_p next;
 254
 255   /* State number used when writing & reading the persistent state.  A
 256      type with a positive number has already been written.  For ease
 257      of debugging, newly allocated types have a unique negative
 258      number.  */
 259   int state_number;
 260
 261   /* Each GTY-ed type which is pointed to by some GTY-ed type knows
 262      the GTY pointer type pointing to it.  See create_pointer
 263      function.  */
 264   type_p pointer_to;
 265
 266   /* Type usage information, computed by set_gc_used_type and
 267      set_gc_used functions.  */
 268   enum gc_used_enum gc_used;
 269
 270   /* The following union is discriminated by the 'kind' field above.  */
 271   union {
 272     /* TYPE__NONE is impossible.  */
 273
 274     /* when TYPE_POINTER:  */
 275     type_p p;
 276
 277     /* when TYPE_STRUCT or TYPE_UNION or TYPE_LANG_STRUCT, we have an
 278        aggregate type containing fields: */
 279     struct {
 280       const char *tag;          /* the aggregate tag, if any.  */
 281       struct fileloc line;      /* the source location.  */
 282       pair_p fields;            /* the linked list of fields.  */
 283       options_p opt;            /* the GTY options if any.  */
 284       lang_bitmap bitmap;       /* the set of front-end languages
 285                                    using that GTY-ed aggregate.  */
 286       /* For TYPE_LANG_STRUCT, the lang_struct field gives the first
 287          element of a linked list of homonymous struct or union types.
 288          Within this list, each homonymous type has as its lang_struct
 289          field the original TYPE_LANG_STRUCT type.  This is a dirty
 290          trick, see the new_structure function for details.  */
 291       type_p lang_struct;
 292
 293       type_p base_class; /* the parent class, if any.  */
 294
 295       /* The following two fields are not serialized in state files, and
 296          are instead reconstructed on load.  */
 297
 298       /* The head of a singly-linked list of immediate descendents in
 299          the inheritance hierarchy.  */
 300       type_p first_subclass;
 301       /* The next in that list.  */
 302       type_p next_sibling_class;
 303
 304       /* Have we already written ggc/pch user func for ptr to this?
 305          (in write_user_func_for_structure_ptr).  */
 306       bool wrote_user_func_for_ptr[NUM_WTK];
 307     } s;
 308
 309     /* when TYPE_SCALAR: */
 310     bool scalar_is_char;
 311
 312     /* when TYPE_ARRAY: */
 313     struct {
 314       type_p p;                 /* The array component type.  */
 315       const char *len;          /* The string if any giving its length.  */
 316     } a;
 317
 318   } u;
 319 };
 320
 321 /* The one and only TYPE_STRING.  */
 322 extern struct type string_type;
 323
 324 /* The two and only TYPE_SCALARs.  Their u.scalar_is_char flags are
 325    set early in main.  */
 326 extern struct type scalar_nonchar;
 327 extern struct type scalar_char;
 328
 329 /* Test if a type is a union, either a plain one or a language
 330    specific one.  */
 331 #define UNION_P(x)                                      \
 332     ((x)->kind == TYPE_UNION                            \
 333      || ((x)->kind == TYPE_LANG_STRUCT                  \
 334          && (x)->u.s.lang_struct->kind == TYPE_UNION))
 335
 336 /* Test if a type is a union or a structure, perhaps a language
 337    specific one.  */
 338 static inline bool
 339 union_or_struct_p (enum typekind kind)
 340 {
 341   return (kind == TYPE_UNION
 342           || kind == TYPE_STRUCT
 343           || kind == TYPE_LANG_STRUCT
 344           || kind == TYPE_USER_STRUCT);
 345 }
 346
 347 static inline bool
 348 union_or_struct_p (const_type_p x)
 349 {
 350   return union_or_struct_p (x->kind);
 351 }
 352
 353 /* Give the file location of a type, if any. */
 354 static inline struct fileloc*
 355 type_fileloc (type_p t)
 356 {
 357   if (!t)
 358     return NULL;
 359   if (union_or_struct_p (t))
 360     return &t->u.s.line;
 361   return NULL;
 362 }
 363
 364 /* Structure representing an output file.  */
 365 struct outf
 366 {
 367   struct outf *next;
 368   const char *name;
 369   size_t buflength;
 370   size_t bufused;
 371   char *buf;
 372 };
 373 typedef struct outf *outf_p;
 374
 375 /* The list of output files.  */
 376 extern outf_p output_files;
 377
 378 /* The output header file that is included into pretty much every
 379    source file.  */
 380 extern outf_p header_file;
 381
 382 /* Print, like fprintf, to O.  No-op if O is NULL.  */
 383 void
 384 oprintf (outf_p o, const char *S, ...)
 385   ATTRIBUTE_PRINTF_2;
 386
 387 /* An output file, suitable for definitions, that can see declarations
 388    made in INPF and is linked into every language that uses INPF.  May
 389    return NULL in plugin mode.  The INPF argument is almost const, but
 390    since the result is cached in its inpoutf field it cannot be
 391    declared const.  */
 392 outf_p get_output_file_with_visibility (input_file* inpf);
 393
 394 /* The name of an output file, suitable for definitions, that can see
 395    declarations made in INPF and is linked into every language that
 396    uses INPF.  May return NULL.  */
 397 const char *get_output_file_name (input_file *inpf);
 398
 399
 400 /* Source directory.  */
 401 extern const char *srcdir;      /* (-S) program argument. */
 402
 403 /* Length of srcdir name.  */
 404 extern size_t srcdir_len;
 405
 406 /* Variable used for reading and writing the state.  */
 407 extern const char *read_state_filename; /* (-r) program argument. */
 408 extern const char *write_state_filename; /* (-w) program argument. */
 409
 410 /* Functions reading and writing the entire gengtype state, called from
 411    main, and implemented in file gengtype-state.c.  */
 412 void read_state (const char* path);
 413 /* Write the state, and update the state_number field in types.  */
 414 void write_state (const char* path);
 415
 416
 417 /* Print an error message.  */
 418 extern void error_at_line
 419 (const struct fileloc *pos, const char *msg, ...) ATTRIBUTE_PRINTF_2;
 420
 421 /* Constructor routines for types.  */
 422 extern void do_typedef (const char *s, type_p t, struct fileloc *pos);
 423 extern void do_scalar_typedef (const char *s, struct fileloc *pos);
 424 extern type_p resolve_typedef (const char *s, struct fileloc *pos);
 425 extern void add_subclass (type_p base, type_p subclass);
 426 extern type_p new_structure (const char *name, enum typekind kind,
 427                              struct fileloc *pos, pair_p fields,
 428                              options_p o, type_p base);
 429 type_p create_user_defined_type (const char *, struct fileloc *);
 430 extern type_p find_structure (const char *s, enum typekind kind);
 431 extern type_p create_scalar_type (const char *name);
 432 extern type_p create_pointer (type_p t);
 433 extern type_p create_array (type_p t, const char *len);
 434 extern pair_p create_field_at (pair_p next, type_p type,
 435                                const char *name, options_p opt,
 436                                struct fileloc *pos);
 437 extern pair_p nreverse_pairs (pair_p list);
 438 extern type_p adjust_field_type (type_p, options_p);
 439 extern void note_variable (const char *s, type_p t, options_p o,
 440                            struct fileloc *pos);
 441
 442 /* Lexer and parser routines.  */
 443 extern int yylex (const char **yylval);
 444 extern void yybegin (const char *fname);
 445 extern void yyend (void);
 446 extern void parse_file (const char *name);
 447 extern bool hit_error;
 448
 449 /* Token codes.  */
 450 enum gty_token
 451 {
 452   EOF_TOKEN = 0,
 453
 454   /* Per standard convention, codes in the range (0, UCHAR_MAX]
 455      represent single characters with those character codes.  */
 456   CHAR_TOKEN_OFFSET = UCHAR_MAX + 1,
 457   GTY_TOKEN = CHAR_TOKEN_OFFSET,
 458   TYPEDEF,
 459   EXTERN,
 460   STATIC,
 461   UNION,
 462   STRUCT,
 463   ENUM,
 464   ELLIPSIS,
 465   PTR_ALIAS,
 466   NESTED_PTR,
 467   USER_GTY,
 468   NUM,
 469   SCALAR,
 470   ID,
 471   STRING,
 472   CHAR,
 473   ARRAY,
 474   IGNORABLE_CXX_KEYWORD,
 475
 476   /* print_token assumes that any token >= FIRST_TOKEN_WITH_VALUE may have
 477      a meaningful value to be printed.  */
 478   FIRST_TOKEN_WITH_VALUE = USER_GTY
 479 };
 480
 481
 482 /* Level for verbose messages, e.g. output file generation...  */
 483 extern int verbosity_level;     /* (-v) program argument.  */
 484
 485 /* For debugging purposes we provide two flags.  */
 486
 487 /* Dump everything to understand gengtype's state. Might be useful to
 488    gengtype users.  */
 489 extern int do_dump;             /* (-d) program argument. */
 490
 491 /* Trace the execution by many DBGPRINTF (with the position inside
 492    gengtype source code).  Only useful to debug gengtype itself.  */
 493 extern int do_debug;            /* (-D) program argument. */
 494
 495 #define DBGPRINTF(Fmt,...) do {if (do_debug)                            \
 496       fprintf (stderr, "%s:%d: " Fmt "\n",                              \
 497                lbasename (__FILE__),__LINE__, ##__VA_ARGS__);} while (0)
 498 void dbgprint_count_type_at (const char *, int, const char *, type_p);
 499 #define DBGPRINT_COUNT_TYPE(Msg,Ty) do {if (do_debug)                   \
 500       dbgprint_count_type_at (__FILE__, __LINE__, Msg, Ty);}while (0)
 501
 502 #define FOR_ALL_INHERITED_FIELDS(TYPE, FIELD_VAR) \
 503   for (type_p sub = (TYPE); sub; sub = sub->u.s.base_class) \
 504     for (FIELD_VAR = sub->u.s.fields; FIELD_VAR; FIELD_VAR = FIELD_VAR->next)
 505
 506 extern bool
 507 opts_have (options_p opts, const char *str);
 508
 509
 510 #endif