gcc/gengtype.h

   1 /* Process source files and output type information.
   2    Copyright (C) 2002-2022 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 /* Table of headers to be included in gtype-desc.cc that are generated
  59    during the build.  These are identified as "./<filename>.h".  */
  60 extern const char **build_headers;
  61 extern size_t num_build_headers;
  62
  63 /* A number of places use the name of this "gengtype.cc" file for a
  64    location for things that we can't rely on the source to define.  We
  65    also need to refer to the "system.h" file specifically.  These two
  66    pointers are initialized early in main.  */
  67 extern input_file* this_file;
  68 extern input_file* system_h_file;
  69
  70 /* Retrieve or create the input_file for a given name, which is a file
  71    path.  This is the only function allocating input_file-s and it is
  72    hash-consing them.  */
  73 input_file* input_file_by_name (const char* name);
  74
  75 /* For F an input_file, return the relative path to F from $(srcdir)
  76    if the latter is a prefix in F, NULL otherwise.  */
  77 const char *get_file_srcdir_relative_path (const input_file *inpf);
  78
  79 /* Get the name of an input file.  */
  80 static inline const char*
  81 get_input_file_name (const input_file *inpf)
  82 {
  83   if (inpf)
  84       return inpf->inpname;
  85   return NULL;
  86 }
  87
  88 /* Return a bitmap which has bit `1 << BASE_FILE_<lang>' set iff
  89    INPUT_FILE is used by <lang>.
  90
  91    This function should be written to assume that a file _is_ used
  92    if the situation is unclear.  If it wrongly assumes a file _is_ used,
  93    a linker error will result.  If it wrongly assumes a file _is not_ used,
  94    some GC roots may be missed, which is a much harder-to-debug problem.
  95   */
  96
  97 static inline lang_bitmap
  98 get_lang_bitmap (const input_file* inpf)
  99 {
 100   if (inpf == NULL)
 101     return 0;
 102   return inpf->inpbitmap;
 103 }
 104
 105 /* Set the bitmap returned by get_lang_bitmap.  The only legitimate
 106    callers of this function are read_input_list & read_state_*.  */
 107 static inline void
 108 set_lang_bitmap (input_file* inpf, lang_bitmap n)
 109 {
 110   gcc_assert (inpf);
 111   inpf->inpbitmap = n;
 112 }
 113
 114 /* Vector of per-language directories.  */
 115 extern const char **lang_dir_names;
 116 extern size_t num_lang_dirs;
 117
 118 /* Data types handed around within, but opaque to, the lexer and parser.  */
 119 typedef struct pair *pair_p;
 120 typedef struct type *type_p;
 121 typedef const struct type *const_type_p;
 122 typedef struct options *options_p;
 123
 124 /* Variables used to communicate between the lexer and the parser.  */
 125 extern int lexer_toplevel_done;
 126 extern struct fileloc lexer_line;
 127
 128 /* Various things, organized as linked lists, needed both in
 129    gengtype.cc & in gengtype-state.cc files.  */
 130 extern pair_p typedefs;
 131 extern type_p structures;
 132 extern pair_p variables;
 133
 134 /* An enum for distinguishing GGC vs PCH.  */
 135
 136 enum write_types_kinds
 137 {
 138   WTK_GGC,
 139   WTK_PCH,
 140
 141   NUM_WTK
 142 };
 143
 144 /* Discrimating kind of types we can understand.  */
 145
 146 enum typekind {
 147   TYPE_NONE=0,          /* Never used, so zeroed memory is invalid.  */
 148   TYPE_UNDEFINED,       /* We have not yet seen a definition for this type.
 149                            If a type is still undefined when generating code,
 150                            an error will be generated.  */
 151   TYPE_SCALAR,          /* Scalar types like char.  */
 152   TYPE_STRING,          /* The string type.  */
 153   TYPE_STRUCT,          /* Type for GTY-ed structs.  */
 154   TYPE_UNION,           /* Type for GTY-ed discriminated unions.  */
 155   TYPE_POINTER,         /* Pointer type to GTY-ed type.  */
 156   TYPE_ARRAY,           /* Array of GTY-ed types.  */
 157   TYPE_CALLBACK,        /* A function pointer that needs relocation if
 158                            the executable has been loaded at a different
 159                            address.  */
 160   TYPE_LANG_STRUCT,     /* GCC front-end language specific structs.
 161                            Various languages may have homonymous but
 162                            different structs.  */
 163   TYPE_USER_STRUCT      /* User defined type.  Walkers and markers for
 164                            this type are assumed to be provided by the
 165                            user.  */
 166 };
 167
 168 /* Discriminating kind for options.  */
 169 enum option_kind {
 170   OPTION_NONE=0,        /* Never used, so zeroed memory is invalid.  */
 171   OPTION_STRING,        /* A string-valued option.  Most options are
 172                            strings.  */
 173   OPTION_TYPE,          /* A type-valued option.  */
 174   OPTION_NESTED         /* Option data for 'nested_ptr'.  */
 175 };
 176
 177
 178 /* A way to pass data through to the output end.  */
 179 struct options {
 180   struct options *next;         /* next option of the same pair.  */
 181   const char *name;             /* GTY option name.  */
 182   enum option_kind kind;        /* discriminating option kind.  */
 183   union {
 184     const char* string;                    /* When OPTION_STRING.  */
 185     type_p type;                           /* When OPTION_TYPE.  */
 186     struct nested_ptr_data* nested;        /* when OPTION_NESTED.  */
 187   } info;
 188 };
 189
 190
 191 /* Option data for the 'nested_ptr' option.  */
 192 struct nested_ptr_data {
 193   type_p type;
 194   const char *convert_to;
 195   const char *convert_from;
 196 };
 197
 198 /* Some functions to create various options structures with name NAME
 199    and info INFO.  NEXT is the next option in the chain.  */
 200
 201 /* Create a string option.  */
 202 options_p create_string_option (options_p next, const char* name,
 203                                 const char* info);
 204
 205 /* Create a type option.  */
 206 options_p create_type_option (options_p next, const char* name,
 207                               type_p info);
 208
 209 /* Create a nested option.  */
 210 options_p create_nested_option (options_p next, const char* name,
 211                                 struct nested_ptr_data* info);
 212
 213 /* Create a nested pointer option.  */
 214 options_p create_nested_ptr_option (options_p next, type_p t,
 215                                     const char *to, const char *from);
 216
 217 /* A name and a type.  */
 218 struct pair {
 219   pair_p next;                  /* The next pair in the linked list.  */
 220   const char *name;             /* The defined name.  */
 221   type_p type;                  /* Its GTY-ed type.  */
 222   struct fileloc line;          /* The file location.  */
 223   options_p opt;                /* GTY options, as a linked list.  */
 224 };
 225
 226 /* Usage information for GTY-ed types.  Gengtype has to care only of
 227    used GTY-ed types.  Types are initially unused, and their usage is
 228    computed by set_gc_used_type and set_gc_used functions.  */
 229
 230 enum gc_used_enum {
 231
 232   /* We need that zeroed types are initially unused.  */
 233   GC_UNUSED=0,
 234
 235   /* The GTY-ed type is used, e.g by a GTY-ed variable or a field
 236      inside a GTY-ed used type.  */
 237   GC_USED,
 238
 239   /* For GTY-ed structures whose definitions we haven't seen so far
 240      when we encounter a pointer to it that is annotated with
 241      ``maybe_undef''.  If after reading in everything we don't have
 242      source file information for it, we assume that it never has been
 243      defined.  */
 244   GC_MAYBE_POINTED_TO,
 245
 246   /* For known GTY-ed structures which are pointed to by GTY-ed
 247      variables or fields.  */
 248   GC_POINTED_TO
 249 };
 250
 251 /* Our type structure describes all types handled by gengtype.  */
 252 struct type {
 253   /* Discriminating kind, cannot be TYPE_NONE.  */
 254   enum typekind kind;
 255
 256   /* For top-level structs or unions, the 'next' field links the
 257      global list 'structures'; for lang_structs, their homonymous structs are
 258      linked using this 'next' field.  The homonymous list starts at the
 259      s.lang_struct field of the lang_struct.  See the new_structure function
 260      for details.  This is tricky!  */
 261   type_p next;
 262
 263   /* State number used when writing & reading the persistent state.  A
 264      type with a positive number has already been written.  For ease
 265      of debugging, newly allocated types have a unique negative
 266      number.  */
 267   int state_number;
 268
 269   /* Each GTY-ed type which is pointed to by some GTY-ed type knows
 270      the GTY pointer type pointing to it.  See create_pointer
 271      function.  */
 272   type_p pointer_to;
 273
 274   /* Type usage information, computed by set_gc_used_type and
 275      set_gc_used functions.  */
 276   enum gc_used_enum gc_used;
 277
 278   /* The following union is discriminated by the 'kind' field above.  */
 279   union {
 280     /* TYPE__NONE is impossible.  */
 281
 282     /* when TYPE_POINTER:  */
 283     type_p p;
 284
 285     /* when TYPE_STRUCT or TYPE_UNION or TYPE_LANG_STRUCT, we have an
 286        aggregate type containing fields: */
 287     struct {
 288       const char *tag;          /* the aggregate tag, if any.  */
 289       struct fileloc line;      /* the source location.  */
 290       pair_p fields;            /* the linked list of fields.  */
 291       options_p opt;            /* the GTY options if any.  */
 292       lang_bitmap bitmap;       /* the set of front-end languages
 293                                    using that GTY-ed aggregate.  */
 294       /* For TYPE_LANG_STRUCT, the lang_struct field gives the first
 295          element of a linked list of homonymous struct or union types.
 296          Within this list, each homonymous type has as its lang_struct
 297          field the original TYPE_LANG_STRUCT type.  This is a dirty
 298          trick, see the new_structure function for details.  */
 299       type_p lang_struct;
 300
 301       type_p base_class; /* the parent class, if any.  */
 302
 303       /* The following two fields are not serialized in state files, and
 304          are instead reconstructed on load.  */
 305
 306       /* The head of a singly-linked list of immediate descendents in
 307          the inheritance hierarchy.  */
 308       type_p first_subclass;
 309       /* The next in that list.  */
 310       type_p next_sibling_class;
 311
 312       /* Have we already written ggc/pch user func for ptr to this?
 313          (in write_user_func_for_structure_ptr).  */
 314       bool wrote_user_func_for_ptr[NUM_WTK];
 315     } s;
 316
 317     /* when TYPE_SCALAR: */
 318     bool scalar_is_char;
 319
 320     /* when TYPE_ARRAY: */
 321     struct {
 322       type_p p;                 /* The array component type.  */
 323       const char *len;          /* The string if any giving its length.  */
 324     } a;
 325
 326   } u;
 327 };
 328
 329 /* The one and only TYPE_STRING.  */
 330 extern struct type string_type;
 331
 332 /* The two and only TYPE_SCALARs.  Their u.scalar_is_char flags are
 333    set early in main.  */
 334 extern struct type scalar_nonchar;
 335 extern struct type scalar_char;
 336
 337 /* The one and only TYPE_CALLBACK.  */
 338 extern struct type callback_type;
 339
 340 /* Test if a type is a union, either a plain one or a language
 341    specific one.  */
 342 #define UNION_P(x)                                      \
 343     ((x)->kind == TYPE_UNION                            \
 344      || ((x)->kind == TYPE_LANG_STRUCT                  \
 345          && (x)->u.s.lang_struct->kind == TYPE_UNION))
 346
 347 /* Test if a type is a union or a structure, perhaps a language
 348    specific one.  */
 349 static inline bool
 350 union_or_struct_p (enum typekind kind)
 351 {
 352   return (kind == TYPE_UNION
 353           || kind == TYPE_STRUCT
 354           || kind == TYPE_LANG_STRUCT
 355           || kind == TYPE_USER_STRUCT);
 356 }
 357
 358 static inline bool
 359 union_or_struct_p (const_type_p x)
 360 {
 361   return union_or_struct_p (x->kind);
 362 }
 363
 364 /* Give the file location of a type, if any. */
 365 static inline struct fileloc*
 366 type_fileloc (type_p t)
 367 {
 368   if (!t)
 369     return NULL;
 370   if (union_or_struct_p (t))
 371     return &t->u.s.line;
 372   return NULL;
 373 }
 374
 375 /* Structure representing an output file.  */
 376 struct outf
 377 {
 378   struct outf *next;
 379   const char *name;
 380   size_t buflength;
 381   size_t bufused;
 382   char *buf;
 383 };
 384 typedef struct outf *outf_p;
 385
 386 /* The list of output files.  */
 387 extern outf_p output_files;
 388
 389 /* The output header file that is included into pretty much every
 390    source file.  */
 391 extern outf_p header_file;
 392
 393 /* Print, like fprintf, to O.  No-op if O is NULL.  */
 394 void
 395 oprintf (outf_p o, const char *S, ...)
 396   ATTRIBUTE_PRINTF_2;
 397
 398 /* An output file, suitable for definitions, that can see declarations
 399    made in INPF and is linked into every language that uses INPF.  May
 400    return NULL in plugin mode.  The INPF argument is almost const, but
 401    since the result is cached in its inpoutf field it cannot be
 402    declared const.  */
 403 outf_p get_output_file_with_visibility (input_file* inpf);
 404
 405 /* The name of an output file, suitable for definitions, that can see
 406    declarations made in INPF and is linked into every language that
 407    uses INPF.  May return NULL.  */
 408 const char *get_output_file_name (input_file *inpf);
 409
 410
 411 /* Source directory.  */
 412 extern const char *srcdir;      /* (-S) program argument. */
 413
 414 /* Length of srcdir name.  */
 415 extern size_t srcdir_len;
 416
 417 /* Variable used for reading and writing the state.  */
 418 extern const char *read_state_filename; /* (-r) program argument. */
 419 extern const char *write_state_filename; /* (-w) program argument. */
 420
 421 /* Functions reading and writing the entire gengtype state, called from
 422    main, and implemented in file gengtype-state.cc.  */
 423 void read_state (const char* path);
 424 /* Write the state, and update the state_number field in types.  */
 425 void write_state (const char* path);
 426
 427
 428 /* Print an error message.  */
 429 extern void error_at_line
 430 (const struct fileloc *pos, const char *msg, ...) ATTRIBUTE_PRINTF_2;
 431
 432 /* Constructor routines for types.  */
 433 extern void do_typedef (const char *s, type_p t, struct fileloc *pos);
 434 extern void do_scalar_typedef (const char *s, struct fileloc *pos);
 435 extern type_p resolve_typedef (const char *s, struct fileloc *pos);
 436 extern void add_subclass (type_p base, type_p subclass);
 437 extern type_p new_structure (const char *name, enum typekind kind,
 438                              struct fileloc *pos, pair_p fields,
 439                              options_p o, type_p base);
 440 type_p create_user_defined_type (const char *, struct fileloc *);
 441 extern type_p find_structure (const char *s, enum typekind kind);
 442 extern type_p create_scalar_type (const char *name);
 443 extern type_p create_pointer (type_p t);
 444 extern type_p create_array (type_p t, const char *len);
 445 extern pair_p create_field_at (pair_p next, type_p type,
 446                                const char *name, options_p opt,
 447                                struct fileloc *pos);
 448 extern pair_p nreverse_pairs (pair_p list);
 449 extern type_p adjust_field_type (type_p, options_p);
 450 extern void note_variable (const char *s, type_p t, options_p o,
 451                            struct fileloc *pos);
 452
 453 /* Lexer and parser routines.  */
 454 extern int yylex (const char **yylval);
 455 extern void yybegin (const char *fname);
 456 extern void yyend (void);
 457 extern void parse_file (const char *name);
 458 extern bool hit_error;
 459
 460 /* Token codes.  */
 461 enum gty_token
 462 {
 463   EOF_TOKEN = 0,
 464
 465   /* Per standard convention, codes in the range (0, UCHAR_MAX]
 466      represent single characters with those character codes.  */
 467   CHAR_TOKEN_OFFSET = UCHAR_MAX + 1,
 468   GTY_TOKEN = CHAR_TOKEN_OFFSET,
 469   TYPEDEF,
 470   EXTERN,
 471   STATIC,
 472   UNION,
 473   STRUCT,
 474   ENUM,
 475   ELLIPSIS,
 476   PTR_ALIAS,
 477   NESTED_PTR,
 478   USER_GTY,
 479   NUM,
 480   SCALAR,
 481   ID,
 482   STRING,
 483   CHAR,
 484   ARRAY,
 485   IGNORABLE_CXX_KEYWORD,
 486
 487   /* print_token assumes that any token >= FIRST_TOKEN_WITH_VALUE may have
 488      a meaningful value to be printed.  */
 489   FIRST_TOKEN_WITH_VALUE = USER_GTY
 490 };
 491
 492
 493 /* Level for verbose messages, e.g. output file generation...  */
 494 extern int verbosity_level;     /* (-v) program argument.  */
 495
 496 /* For debugging purposes we provide two flags.  */
 497
 498 /* Dump everything to understand gengtype's state. Might be useful to
 499    gengtype users.  */
 500 extern int do_dump;             /* (-d) program argument. */
 501
 502 /* Trace the execution by many DBGPRINTF (with the position inside
 503    gengtype source code).  Only useful to debug gengtype itself.  */
 504 extern int do_debug;            /* (-D) program argument. */
 505
 506 #define DBGPRINTF(Fmt,...) do {if (do_debug)                            \
 507       fprintf (stderr, "%s:%d: " Fmt "\n",                              \
 508                lbasename (__FILE__),__LINE__, ##__VA_ARGS__);} while (0)
 509 void dbgprint_count_type_at (const char *, int, const char *, type_p);
 510 #define DBGPRINT_COUNT_TYPE(Msg,Ty) do {if (do_debug)                   \
 511       dbgprint_count_type_at (__FILE__, __LINE__, Msg, Ty);}while (0)
 512
 513 #define FOR_ALL_INHERITED_FIELDS(TYPE, FIELD_VAR) \
 514   for (type_p sub = (TYPE); sub; sub = sub->u.s.base_class) \
 515     for (FIELD_VAR = sub->u.s.fields; FIELD_VAR; FIELD_VAR = FIELD_VAR->next)
 516
 517 extern bool
 518 opts_have (options_p opts, const char *str);
 519
 520
 521 #endif