src/m4.h

   1 /* GNU m4 -- A simple macro processor
   2
   3    Copyright (C) 1989, 1990, 1991, 1992, 1993, 1994, 2004, 2005, 2006, 2007,
   4    2008 Free Software Foundation, Inc.
   5
   6    This file is part of GNU M4.
   7
   8    GNU M4 is free software: you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation, either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    GNU M4 is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 /* We use <config.h> instead of "config.h" so that a compilation
  23    using -I. -I$srcdir will use ./config.h rather than $srcdir/config.h
  24    (which it would do because it found this file in $srcdir).  */
  25
  26 #include <config.h>
  27
  28 #include <assert.h>
  29 #include <ctype.h>
  30 #include <errno.h>
  31 #include <limits.h>
  32 #include <stdbool.h>
  33 #include <stdint.h>
  34 #include <string.h>
  35 #include <sys/types.h>
  36
  37 #include "binary-io.h"
  38 #include "clean-temp.h"
  39 #include "cloexec.h"
  40 #include "close-stream.h"
  41 #include "closein.h"
  42 #include "error.h"
  43 #include "exitfail.h"
  44 #include "intprops.h"
  45 #include "obstack.h"
  46 #include "quotearg.h"
  47 #include "stdio--.h"
  48 #include "stdlib--.h"
  49 #include "unistd--.h"
  50 #include "vasnprintf.h"
  51 #include "verror.h"
  52 #include "xalloc.h"
  53 #include "xprintf.h"
  54 #include "xvasprintf.h"
  55
  56 /* Canonicalize UNIX recognition macros.  */
  57 #if defined unix || defined __unix || defined __unix__ \
  58   || defined _POSIX_VERSION || defined _POSIX2_VERSION \
  59   || defined __NetBSD__ || defined __OpenBSD__ \
  60   || defined __APPLE__ || defined __APPLE_CC__
  61 # define UNIX 1
  62 #endif
  63
  64 /* Canonicalize Windows recognition macros.  */
  65 #if (defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__
  66 # define W32_NATIVE 1
  67 #endif
  68
  69 /* Canonicalize OS/2 recognition macro.  */
  70 #ifdef __EMX__
  71 # define OS2 1
  72 #endif
  73
  74 /* Used for version mismatch, when -R detects a frozen file it can't parse.  */
  75 #define EXIT_MISMATCH 63
  76
  77 /* M4 1.4.x is not yet internationalized.  But when it is, this can be
  78    redefined as gettext().  */
  79 #define _(STRING) STRING
  80 \f
  81 /* Various declarations.  */
  82
  83 /* Describes a pair of strings, such as begin and end quotes.  */
  84 struct string_pair
  85   {
  86     char *str1;
  87     size_t len1;
  88     char *str2;
  89     size_t len2;
  90   };
  91 typedef struct string_pair string_pair;
  92
  93 /* Memory allocation.  */
  94 #define obstack_chunk_alloc     xmalloc
  95 #define obstack_chunk_free      free
  96
  97 /* These must come first.  */
  98 typedef struct input_block input_block;
  99 typedef struct token_data token_data;
 100 typedef struct macro_arguments macro_arguments;
 101 typedef void builtin_func (struct obstack *, int, macro_arguments *);
 102
 103 /* Gnulib's stdbool doesn't work with bool bitfields.  For nicer
 104    debugging, use bool when we know it works, but use the more
 105    portable unsigned int elsewhere.  */
 106 #if __GNUC__ > 2
 107 typedef bool bool_bitfield;
 108 #else
 109 typedef unsigned int bool_bitfield;
 110 #endif /* !__GNUC__ */
 111
 112 /* Take advantage of GNU C compiler source level optimization hints,
 113    using portable macros.  */
 114 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 6)
 115 #  define M4_GNUC_ATTRIBUTE(args)       __attribute__ (args)
 116 #else
 117 #  define M4_GNUC_ATTRIBUTE(args)
 118 #endif  /* __GNUC__ */
 119
 120 #define M4_GNUC_UNUSED          M4_GNUC_ATTRIBUTE ((__unused__))
 121 #define M4_GNUC_PRINTF(fmt, arg)                        \
 122   M4_GNUC_ATTRIBUTE ((__format__ (__printf__, fmt, arg)))
 123 \f
 124 /* File: m4.c  --- global definitions.  */
 125
 126 /* Option flags.  */
 127 extern int sync_output;                 /* -s */
 128 extern int debug_level;                 /* -d */
 129 extern size_t hash_table_size;          /* -H */
 130 extern int no_gnu_extensions;           /* -G */
 131 extern int prefix_all_builtins;         /* -P */
 132 extern int max_debug_argument_length;   /* -l */
 133 extern int suppress_warnings;           /* -Q */
 134 extern int warning_status;              /* -E */
 135 extern int nesting_limit;               /* -L */
 136 #ifdef ENABLE_CHANGEWORD
 137 extern const char *user_word_regexp;    /* -W */
 138 #endif
 139
 140 /* Error handling.  */
 141 extern int retcode;
 142 extern const char *program_name;
 143
 144 void m4_error (int, int, const char *, const char *, ...)
 145   M4_GNUC_PRINTF (4, 5);
 146 void m4_error_at_line (int, int, const char *, int, const char *,
 147                        const char *, ...) M4_GNUC_PRINTF (6, 7);
 148 void m4_warn (int, const char *, const char *, ...) M4_GNUC_PRINTF (3, 4);
 149 void m4_warn_at_line (int, const char *, int, const char *,
 150                       const char *, ...) M4_GNUC_PRINTF (5, 6);
 151
 152 #ifdef USE_STACKOVF
 153 void setup_stackovf_trap (char *const *, char *const *,
 154                           void (*handler) (void));
 155 #endif
 156 \f
 157 /* File: debug.c  --- debugging and tracing function.  */
 158
 159 extern FILE *debug;
 160
 161 /* The value of debug_level is a bitmask of the following.  */
 162
 163 /* a: show arglist in trace output */
 164 #define DEBUG_TRACE_ARGS 0x001
 165 /* e: show expansion in trace output */
 166 #define DEBUG_TRACE_EXPANSION 0x002
 167 /* q: quote args and expansion in trace output */
 168 #define DEBUG_TRACE_QUOTE 0x004
 169 /* t: trace all macros -- overrides trace{on,off} */
 170 #define DEBUG_TRACE_ALL 0x008
 171 /* l: add line numbers to trace output */
 172 #define DEBUG_TRACE_LINE 0x010
 173 /* f: add file name to trace output */
 174 #define DEBUG_TRACE_FILE 0x020
 175 /* p: trace path search of include files */
 176 #define DEBUG_TRACE_PATH 0x040
 177 /* c: show macro call before args collection */
 178 #define DEBUG_TRACE_CALL 0x080
 179 /* i: trace changes of input files */
 180 #define DEBUG_TRACE_INPUT 0x100
 181 /* x: add call id to trace output */
 182 #define DEBUG_TRACE_CALLID 0x200
 183
 184 /* V: very verbose --  print everything */
 185 #define DEBUG_TRACE_VERBOSE 0x377
 186 /* default flags -- equiv: aeq */
 187 #define DEBUG_TRACE_DEFAULT 0x007
 188
 189 #define DEBUG_PRINT1(Fmt, Arg1)                                 \
 190   do                                                            \
 191     {                                                           \
 192       if (debug != NULL)                                        \
 193         xfprintf (debug, Fmt, Arg1);                            \
 194     }                                                           \
 195   while (0)
 196
 197 #define DEBUG_PRINT3(Fmt, Arg1, Arg2, Arg3)                     \
 198   do                                                            \
 199     {                                                           \
 200       if (debug != NULL)                                        \
 201         xfprintf (debug, Fmt, Arg1, Arg2, Arg3);                \
 202     }                                                           \
 203   while (0)
 204
 205 #define DEBUG_MESSAGE(Fmt)                                      \
 206   do                                                            \
 207     {                                                           \
 208       if (debug != NULL)                                        \
 209         {                                                       \
 210           debug_message_prefix ();                              \
 211           xfprintf (debug, Fmt);                                \
 212           putc ('\n', debug);                                   \
 213         }                                                       \
 214     }                                                           \
 215   while (0)
 216
 217 #define DEBUG_MESSAGE1(Fmt, Arg1)                               \
 218   do                                                            \
 219     {                                                           \
 220       if (debug != NULL)                                        \
 221         {                                                       \
 222           debug_message_prefix ();                              \
 223           xfprintf (debug, Fmt, Arg1);                          \
 224           putc ('\n', debug);                                   \
 225         }                                                       \
 226     }                                                           \
 227   while (0)
 228
 229 #define DEBUG_MESSAGE2(Fmt, Arg1, Arg2)                         \
 230   do                                                            \
 231     {                                                           \
 232       if (debug != NULL)                                        \
 233         {                                                       \
 234           debug_message_prefix ();                              \
 235           xfprintf (debug, Fmt, Arg1, Arg2);                    \
 236           putc ('\n', debug);                                   \
 237         }                                                       \
 238     }                                                           \
 239   while (0)
 240
 241 void debug_init (void);
 242 int debug_decode (const char *);
 243 void debug_flush_files (void);
 244 bool debug_set_output (const char *, const char *);
 245 void debug_message_prefix (void);
 246
 247 void trace_prepre (const char *, int);
 248 void trace_pre (const char *, int, macro_arguments *);
 249 void trace_post (const char *, int, macro_arguments *,
 250                  const input_block *);
 251
 252 \f
 253 /* File: input.c  --- lexical definitions.  */
 254
 255 typedef struct token_chain token_chain;
 256
 257 /* Various different token types.  Avoid overlap with token_data_type,
 258    since the shared prefix of the enumerators is a bit confusing.  */
 259 enum token_type
 260 {
 261   TOKEN_EOF = 4,/* End of file, TOKEN_VOID.  */
 262   TOKEN_STRING, /* Quoted string or comment, TOKEN_TEXT or TOKEN_COMP.  */
 263   TOKEN_WORD,   /* An identifier, TOKEN_TEXT.  */
 264   TOKEN_OPEN,   /* Active character `(', TOKEN_TEXT.  */
 265   TOKEN_COMMA,  /* Active character `,', TOKEN_TEXT.  */
 266   TOKEN_CLOSE,  /* Active character `)', TOKEN_TEXT.  */
 267   TOKEN_SIMPLE, /* Any other single character, TOKEN_TEXT.  */
 268   TOKEN_MACDEF, /* A macro's definition (see "defn"), TOKEN_FUNC.  */
 269   TOKEN_ARGV    /* A series of parameters, TOKEN_COMP.  */
 270 };
 271
 272 /* The data for a token, a macro argument, and a macro definition.  */
 273 enum token_data_type
 274 {
 275   TOKEN_VOID,   /* Token still being constructed, u is invalid.  */
 276   TOKEN_TEXT,   /* Straight text, u.u_t is valid.  */
 277   TOKEN_FUNC,   /* Builtin function definition, u.func is valid.  */
 278   TOKEN_COMP    /* Composite argument, u.u_c is valid.  */
 279 };
 280
 281 /* A link in a chain of token data.  */
 282 enum token_chain_type
 283 {
 284   CHAIN_STR,    /* Link contains a string, u.u_s is valid.  */
 285   /* TODO add CHAIN_FUNC.  */
 286   CHAIN_ARGV    /* Link contains a $@ reference, u.u_a is valid.  */
 287 };
 288
 289 /* Composite tokens are built of a linked list of chains.  Each link
 290    of the chain is either a single text reference (ie. $1), or an argv
 291    reference (ie. $@).  */
 292 struct token_chain
 293 {
 294   token_chain *next;            /* Pointer to next link of chain.  */
 295   enum token_chain_type type;   /* Type of this link.  */
 296   unsigned int quote_age;       /* Quote_age of this link of chain, or 0.  */
 297   union
 298     {
 299       struct
 300         {
 301           const char *str;      /* Pointer to text.  */
 302           size_t len;           /* Remaining length of str.  */
 303           int level;            /* Expansion level of link content, or -1.  */
 304         }
 305       u_s;
 306       struct
 307         {
 308           macro_arguments *argv;        /* Reference to earlier $@.  */
 309           unsigned int index;           /* Argument index within argv.  */
 310           bool_bitfield flatten : 1;    /* True to treat builtins as text.  */
 311           bool_bitfield comma : 1;      /* True when `,' is next input.  */
 312           bool_bitfield skip_last : 1;  /* True if last argument omitted.  */
 313           bool_bitfield has_func : 1;   /* True if argv includes func.  */
 314           const string_pair *quotes;    /* NULL for $*, quotes for $@.  */
 315         }
 316       u_a;
 317     }
 318   u;
 319 };
 320
 321 /* The content of a token or macro argument.  */
 322 struct token_data
 323 {
 324   enum token_data_type type;
 325   union
 326     {
 327       struct
 328         {
 329           /* We don't support NUL in text, yet.  So len is just a
 330              cache for now.  But it will be essential if we ever DO
 331              support NUL.  */
 332           size_t len;
 333           char *text; /* The contents of the token.  */
 334           /* The value of quote_age when this token was scanned.  If
 335              this token is later encountered in the context of
 336              scanning a quoted string, and quote_age has not changed,
 337              then rescanning this string is provably unnecessary.  If
 338              zero, then this string potentially contains content that
 339              might change the parse on rescan.  Ignored for 0 len.  */
 340           unsigned int quote_age;
 341 #ifdef ENABLE_CHANGEWORD
 342           /* If changeword is in effect, and contains a () group, then
 343              this contains the entire token, while text contains the
 344              portion that matched the () group to form a macro name.
 345              Otherwise, this field is unused.  */
 346           const char *original_text;
 347 #endif
 348         }
 349       u_t;
 350       builtin_func *func;
 351
 352       /* Composite text: a linked list of straight text and $@
 353          placeholders.  */
 354       struct
 355         {
 356           token_chain *chain;           /* First link of the chain.  */
 357           token_chain *end;             /* Last link of the chain.  */
 358           bool_bitfield wrapper : 1;    /* True if this is a $@ ref.  */
 359           bool_bitfield has_func : 1;   /* True if chain includes func.  */
 360         }
 361       u_c;
 362     }
 363   u;
 364 };
 365
 366 #define TOKEN_DATA_TYPE(Td)             ((Td)->type)
 367 #define TOKEN_DATA_LEN(Td)              ((Td)->u.u_t.len)
 368 #define TOKEN_DATA_TEXT(Td)             ((Td)->u.u_t.text)
 369 #define TOKEN_DATA_QUOTE_AGE(Td)        ((Td)->u.u_t.quote_age)
 370 #ifdef ENABLE_CHANGEWORD
 371 # define TOKEN_DATA_ORIG_TEXT(Td)       ((Td)->u.u_t.original_text)
 372 #endif
 373 #define TOKEN_DATA_FUNC(Td)             ((Td)->u.func)
 374
 375 typedef enum token_type token_type;
 376 typedef enum token_data_type token_data_type;
 377
 378 void input_init (void);
 379 token_type peek_token (void);
 380 token_type next_token (token_data *, int *, struct obstack *, bool,
 381                        const char *);
 382 void skip_line (const char *);
 383
 384 /* push back input */
 385 void make_text_link (struct obstack *, token_chain **, token_chain **);
 386 void push_file (FILE *, const char *, bool);
 387 void push_macro (builtin_func *);
 388 struct obstack *push_string_init (void);
 389 bool push_token (token_data *, int, bool);
 390 const input_block *push_string_finish (void);
 391 struct obstack *push_wrapup_init (void);
 392 void push_wrapup_finish (void);
 393 bool pop_wrapup (void);
 394 void input_print (struct obstack *, const input_block *);
 395
 396 /* current input file, and line */
 397 extern const char *current_file;
 398 extern int current_line;
 399
 400 /* left and right quote, begin and end comment */
 401 extern string_pair curr_comm;
 402 extern string_pair curr_quote;
 403
 404 #define DEF_LQUOTE "`"
 405 #define DEF_RQUOTE "\'"
 406 #define DEF_BCOMM "#"
 407 #define DEF_ECOMM "\n"
 408
 409 void set_quotes (const char *, const char *);
 410 void set_comment (const char *, const char *);
 411 #ifdef ENABLE_CHANGEWORD
 412 void set_word_regexp (const char *, const char *);
 413 #endif
 414 unsigned int quote_age (void);
 415 bool safe_quotes (void);
 416 const string_pair *quote_cache (struct obstack *, unsigned int,
 417                                 const string_pair *);
 418 \f
 419 /* File: output.c --- output functions.  */
 420 extern int current_diversion;
 421 extern int output_current_line;
 422
 423 void output_init (void);
 424 void output_exit (void);
 425 void output_text (const char *, int);
 426 void divert_text (struct obstack *, const char *, int, int);
 427 bool shipout_string_trunc (struct obstack *, const char *, size_t, int *);
 428 void make_diversion (int);
 429 void insert_diversion (int);
 430 void insert_file (FILE *);
 431 void freeze_diversions (FILE *);
 432 \f
 433 /* File symtab.c  --- symbol table definitions.  */
 434
 435 /* Operation modes for lookup_symbol ().  */
 436 enum symbol_lookup
 437 {
 438   SYMBOL_LOOKUP,
 439   SYMBOL_INSERT,
 440   SYMBOL_DELETE,
 441   SYMBOL_PUSHDEF,
 442   SYMBOL_POPDEF
 443 };
 444
 445 /* Symbol table entry.  */
 446 struct symbol
 447 {
 448   struct symbol *next;
 449   bool_bitfield traced : 1;
 450   bool_bitfield shadowed : 1;
 451   bool_bitfield macro_args : 1;
 452   bool_bitfield blind_no_args : 1;
 453   bool_bitfield deleted : 1;
 454   int pending_expansions;
 455
 456   char *name;
 457   token_data data;  /* Type should be only TOKEN_TEXT or TOKEN_FUNC.  */
 458 };
 459
 460 #define SYMBOL_NEXT(S)          ((S)->next)
 461 #define SYMBOL_TRACED(S)        ((S)->traced)
 462 #define SYMBOL_SHADOWED(S)      ((S)->shadowed)
 463 #define SYMBOL_MACRO_ARGS(S)    ((S)->macro_args)
 464 #define SYMBOL_BLIND_NO_ARGS(S) ((S)->blind_no_args)
 465 #define SYMBOL_DELETED(S)       ((S)->deleted)
 466 #define SYMBOL_PENDING_EXPANSIONS(S) ((S)->pending_expansions)
 467 #define SYMBOL_NAME(S)          ((S)->name)
 468 #define SYMBOL_TYPE(S)          (TOKEN_DATA_TYPE (&(S)->data))
 469 #define SYMBOL_TEXT(S)          (TOKEN_DATA_TEXT (&(S)->data))
 470 #define SYMBOL_FUNC(S)          (TOKEN_DATA_FUNC (&(S)->data))
 471
 472 typedef enum symbol_lookup symbol_lookup;
 473 typedef struct symbol symbol;
 474 typedef void hack_symbol (symbol *, void *);
 475
 476 #define HASHMAX 509             /* default, overridden by -Hsize */
 477
 478 extern symbol **symtab;
 479
 480 void free_symbol (symbol *sym);
 481 void symtab_init (void);
 482 symbol *lookup_symbol (const char *, symbol_lookup);
 483 void hack_all_symbols (hack_symbol *, void *);
 484 \f
 485 /* File: macro.c  --- macro expansion.  */
 486
 487 extern int expansion_level;
 488
 489 void expand_input (void);
 490 void call_macro (symbol *, int, macro_arguments *, struct obstack *);
 491 size_t adjust_refcount (int, bool);
 492
 493 bool arg_adjust_refcount (macro_arguments *, bool);
 494 unsigned int arg_argc (macro_arguments *);
 495 token_data_type arg_type (macro_arguments *, unsigned int);
 496 const char *arg_text (macro_arguments *, unsigned int);
 497 bool arg_equal (macro_arguments *, unsigned int, unsigned int);
 498 bool arg_empty (macro_arguments *, unsigned int);
 499 size_t arg_len (macro_arguments *, unsigned int);
 500 builtin_func *arg_func (macro_arguments *, unsigned int);
 501 struct obstack *arg_scratch (void);
 502 bool arg_print (struct obstack *, macro_arguments *, unsigned int,
 503                 const string_pair *, bool, const char *, int *, bool);
 504 macro_arguments *make_argv_ref (macro_arguments *, const char *, size_t,
 505                                 bool, bool);
 506 void push_arg (struct obstack *, macro_arguments *, unsigned int);
 507 void push_arg_quote (struct obstack *, macro_arguments *, unsigned int,
 508                      const string_pair *);
 509 void push_args (struct obstack *, macro_arguments *, bool, bool);
 510
 511 /* Grab the text at argv index I.  Assumes macro_argument *argv is in
 512    scope, and aborts if the argument is not text.  */
 513 #define ARG(i) arg_text (argv, i)
 514
 515 /* Grab the text length at argv index I.  Assumes macro_argument *argv
 516    is in scope, and aborts if the argument is not text.  */
 517 #define ARG_LEN(i) arg_len (argv, i)
 518
 519 \f
 520 /* File: builtin.c  --- builtins.  */
 521
 522 struct builtin
 523 {
 524   const char *name;
 525   bool_bitfield gnu_extension : 1;
 526   bool_bitfield groks_macro_args : 1;
 527   bool_bitfield blind_if_no_args : 1;
 528   builtin_func *func;
 529 };
 530
 531 struct predefined
 532 {
 533   const char *unix_name;
 534   const char *gnu_name;
 535   const char *func;
 536 };
 537
 538 typedef struct builtin builtin;
 539 typedef struct predefined predefined;
 540 struct re_pattern_buffer;
 541 struct re_registers;
 542
 543 /* The default sequence detects multi-digit parameters (obsolete after
 544    1.4.x), and any use of extended arguments with the default ${}
 545    syntax (new in 2.0).  */
 546 #define DEFAULT_MACRO_SEQUENCE "\\$\\({[^}]*}\\|[0-9][0-9]+\\)"
 547
 548 void builtin_init (void);
 549 bool bad_argc (const char *, int, unsigned int, unsigned int);
 550 void define_builtin (const char *, const builtin *, symbol_lookup);
 551 void set_macro_sequence (const char *);
 552 void free_regex (void);
 553 void define_user_macro (const char *, size_t, const char *, symbol_lookup);
 554 void undivert_all (void);
 555 void expand_user_macro (struct obstack *, symbol *, int, macro_arguments *);
 556 void m4_placeholder (struct obstack *, int, macro_arguments *);
 557 void init_pattern_buffer (struct re_pattern_buffer *, struct re_registers *);
 558 const char *ntoa (int32_t, int);
 559
 560 const builtin *find_builtin_by_addr (builtin_func *);
 561 const builtin *find_builtin_by_name (const char *);
 562 void func_print (struct obstack *, const builtin *, bool, const string_pair *);
 563 \f
 564 /* File: path.c  --- path search for include files.  */
 565
 566 void include_init (void);
 567 void include_env_init (void);
 568 void add_include_directory (const char *);
 569 FILE *m4_path_search (const char *, char **);
 570 \f
 571 /* File: eval.c  --- expression evaluation.  */
 572
 573 bool evaluate (const char *, const char *, int32_t *);
 574 \f
 575 /* File: format.c  --- printf like formatting.  */
 576
 577 void format (struct obstack *, int, macro_arguments *);
 578 \f
 579 /* File: freeze.c --- frozen state files.  */
 580
 581 void produce_frozen_state (const char *);
 582 void reload_frozen_state (const char *);
 583 \f
 584 /* Debugging the memory allocator.  */
 585
 586 #ifdef WITH_DMALLOC
 587 # define DMALLOC_FUNC_CHECK
 588 # include <dmalloc.h>
 589 #endif
 590
 591 /* Other debug stuff.  */
 592
 593 #ifdef DEBUG
 594 # define DEBUG_INCL   1
 595 # define DEBUG_INPUT  1
 596 # define DEBUG_MACRO  1
 597 # define DEBUG_OUTPUT 1
 598 # define DEBUG_REGEX  1
 599 # define DEBUG_STKOVF 1
 600 # define DEBUG_SYM    1
 601 #endif
 602
 603 /* Convert a possibly-signed character to an unsigned character.  This is
 604    a bit safer than casting to unsigned char, since it catches some type
 605    errors that the cast doesn't.  */
 606 #if HAVE_INLINE
 607 static inline unsigned char to_uchar (char ch) { return ch; }
 608 #else
 609 # define to_uchar(C) ((unsigned char) (C))
 610 #endif