/* Generate kernel symbol version hashes.
     Copyright 1996, 1997 Linux International.
  
     New implementation contributed by Richard Henderson <rth@tamu.edu>
     Based on original work by Bjorn Ekwall <bj0rn@blox.se>
  
     This file was part of the Linux modutils 2.4.22: moved back into the
     kernel sources by Rusty Russell/Kai Germaschewski.
  
     This program is free software; you can redistribute it and/or modify it
     under the terms of the GNU General Public License as published by the
     Free Software Foundation; either version 2 of the License, or (at your
     option) any later version.
  
     This program is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     General Public License for more details.
  
     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software Foundation,
     Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  
  #include <stdio.h>
  #include <string.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <assert.h>
  #include <stdarg.h>
  #ifdef __GNU_LIBRARY__
  #include <getopt.h>
  #endif				/* __GNU_LIBRARY__ */
  
  #include "genksyms.h"
  /*----------------------------------------------------------------------*/
  
  #define HASH_BUCKETS  4096
  
  static struct symbol *symtab[HASH_BUCKETS];
  static FILE *debugfile;
  
  int cur_line = 1;
  char *cur_filename, *source_file;
  int in_source_file;
  
  static int flag_debug, flag_dump_defs, flag_reference, flag_dump_types,
  	   flag_preserve, flag_warnings;
  static const char *mod_prefix = "";
  
  static int errors;
  static int nsyms;
  
  static struct symbol *expansion_trail;
  static struct symbol *visited_symbols;
  
  static const struct {
  	int n;
  	const char *name;
  } symbol_types[] = {
  	[SYM_NORMAL]     = { 0, NULL},
  	[SYM_TYPEDEF]    = {'t', "typedef"},
  	[SYM_ENUM]       = {'e', "enum"},
  	[SYM_STRUCT]     = {'s', "struct"},
  	[SYM_UNION]      = {'u', "union"},
  	[SYM_ENUM_CONST] = {'E', "enum constant"},
  };
  
  static int equal_list(struct string_list *a, struct string_list *b);
  static void print_list(FILE * f, struct string_list *list);
  static struct string_list *concat_list(struct string_list *start, ...);
  static struct string_list *mk_node(const char *string);
  static void print_location(void);
  static void print_type_name(enum symbol_type type, const char *name);
  
  /*----------------------------------------------------------------------*/
  
  static const unsigned int crctab32[] = {
  	0x00000000U, 0x77073096U, 0xee0e612cU, 0x990951baU, 0x076dc419U,
  	0x706af48fU, 0xe963a535U, 0x9e6495a3U, 0x0edb8832U, 0x79dcb8a4U,
  	0xe0d5e91eU, 0x97d2d988U, 0x09b64c2bU, 0x7eb17cbdU, 0xe7b82d07U,
  	0x90bf1d91U, 0x1db71064U, 0x6ab020f2U, 0xf3b97148U, 0x84be41deU,
  	0x1adad47dU, 0x6ddde4ebU, 0xf4d4b551U, 0x83d385c7U, 0x136c9856U,
  	0x646ba8c0U, 0xfd62f97aU, 0x8a65c9ecU, 0x14015c4fU, 0x63066cd9U,
  	0xfa0f3d63U, 0x8d080df5U, 0x3b6e20c8U, 0x4c69105eU, 0xd56041e4U,
  	0xa2677172U, 0x3c03e4d1U, 0x4b04d447U, 0xd20d85fdU, 0xa50ab56bU,
  	0x35b5a8faU, 0x42b2986cU, 0xdbbbc9d6U, 0xacbcf940U, 0x32d86ce3U,
  	0x45df5c75U, 0xdcd60dcfU, 0xabd13d59U, 0x26d930acU, 0x51de003aU,
  	0xc8d75180U, 0xbfd06116U, 0x21b4f4b5U, 0x56b3c423U, 0xcfba9599U,
  	0xb8bda50fU, 0x2802b89eU, 0x5f058808U, 0xc60cd9b2U, 0xb10be924U,
  	0x2f6f7c87U, 0x58684c11U, 0xc1611dabU, 0xb6662d3dU, 0x76dc4190U,
  	0x01db7106U, 0x98d220bcU, 0xefd5102aU, 0x71b18589U, 0x06b6b51fU,
  	0x9fbfe4a5U, 0xe8b8d433U, 0x7807c9a2U, 0x0f00f934U, 0x9609a88eU,
  	0xe10e9818U, 0x7f6a0dbbU, 0x086d3d2dU, 0x91646c97U, 0xe6635c01U,
  	0x6b6b51f4U, 0x1c6c6162U, 0x856530d8U, 0xf262004eU, 0x6c0695edU,
  	0x1b01a57bU, 0x8208f4c1U, 0xf50fc457U, 0x65b0d9c6U, 0x12b7e950U,
  	0x8bbeb8eaU, 0xfcb9887cU, 0x62dd1ddfU, 0x15da2d49U, 0x8cd37cf3U,
  	0xfbd44c65U, 0x4db26158U, 0x3ab551ceU, 0xa3bc0074U, 0xd4bb30e2U,
  	0x4adfa541U, 0x3dd895d7U, 0xa4d1c46dU, 0xd3d6f4fbU, 0x4369e96aU,
  	0x346ed9fcU, 0xad678846U, 0xda60b8d0U, 0x44042d73U, 0x33031de5U,
  	0xaa0a4c5fU, 0xdd0d7cc9U, 0x5005713cU, 0x270241aaU, 0xbe0b1010U,
  	0xc90c2086U, 0x5768b525U, 0x206f85b3U, 0xb966d409U, 0xce61e49fU,
  	0x5edef90eU, 0x29d9c998U, 0xb0d09822U, 0xc7d7a8b4U, 0x59b33d17U,
  	0x2eb40d81U, 0xb7bd5c3bU, 0xc0ba6cadU, 0xedb88320U, 0x9abfb3b6U,
  	0x03b6e20cU, 0x74b1d29aU, 0xead54739U, 0x9dd277afU, 0x04db2615U,
  	0x73dc1683U, 0xe3630b12U, 0x94643b84U, 0x0d6d6a3eU, 0x7a6a5aa8U,
  	0xe40ecf0bU, 0x9309ff9dU, 0x0a00ae27U, 0x7d079eb1U, 0xf00f9344U,
  	0x8708a3d2U, 0x1e01f268U, 0x6906c2feU, 0xf762575dU, 0x806567cbU,
  	0x196c3671U, 0x6e6b06e7U, 0xfed41b76U, 0x89d32be0U, 0x10da7a5aU,
  	0x67dd4accU, 0xf9b9df6fU, 0x8ebeeff9U, 0x17b7be43U, 0x60b08ed5U,
  	0xd6d6a3e8U, 0xa1d1937eU, 0x38d8c2c4U, 0x4fdff252U, 0xd1bb67f1U,
  	0xa6bc5767U, 0x3fb506ddU, 0x48b2364bU, 0xd80d2bdaU, 0xaf0a1b4cU,
  	0x36034af6U, 0x41047a60U, 0xdf60efc3U, 0xa867df55U, 0x316e8eefU,
  	0x4669be79U, 0xcb61b38cU, 0xbc66831aU, 0x256fd2a0U, 0x5268e236U,
  	0xcc0c7795U, 0xbb0b4703U, 0x220216b9U, 0x5505262fU, 0xc5ba3bbeU,
  	0xb2bd0b28U, 0x2bb45a92U, 0x5cb36a04U, 0xc2d7ffa7U, 0xb5d0cf31U,
  	0x2cd99e8bU, 0x5bdeae1dU, 0x9b64c2b0U, 0xec63f226U, 0x756aa39cU,
  	0x026d930aU, 0x9c0906a9U, 0xeb0e363fU, 0x72076785U, 0x05005713U,
  	0x95bf4a82U, 0xe2b87a14U, 0x7bb12baeU, 0x0cb61b38U, 0x92d28e9bU,
  	0xe5d5be0dU, 0x7cdcefb7U, 0x0bdbdf21U, 0x86d3d2d4U, 0xf1d4e242U,
  	0x68ddb3f8U, 0x1fda836eU, 0x81be16cdU, 0xf6b9265bU, 0x6fb077e1U,
  	0x18b74777U, 0x88085ae6U, 0xff0f6a70U, 0x66063bcaU, 0x11010b5cU,
  	0x8f659effU, 0xf862ae69U, 0x616bffd3U, 0x166ccf45U, 0xa00ae278U,
  	0xd70dd2eeU, 0x4e048354U, 0x3903b3c2U, 0xa7672661U, 0xd06016f7U,
  	0x4969474dU, 0x3e6e77dbU, 0xaed16a4aU, 0xd9d65adcU, 0x40df0b66U,
  	0x37d83bf0U, 0xa9bcae53U, 0xdebb9ec5U, 0x47b2cf7fU, 0x30b5ffe9U,
  	0xbdbdf21cU, 0xcabac28aU, 0x53b39330U, 0x24b4a3a6U, 0xbad03605U,
  	0xcdd70693U, 0x54de5729U, 0x23d967bfU, 0xb3667a2eU, 0xc4614ab8U,
  	0x5d681b02U, 0x2a6f2b94U, 0xb40bbe37U, 0xc30c8ea1U, 0x5a05df1bU,
  	0x2d02ef8dU
  };
  
  static unsigned long partial_crc32_one(unsigned char c, unsigned long crc)
  {
  	return crctab32[(crc ^ c) & 0xff] ^ (crc >> 8);
  }
  
  static unsigned long partial_crc32(const char *s, unsigned long crc)
  {
  	while (*s)
  		crc = partial_crc32_one(*s++, crc);
  	return crc;
  }
  
  static unsigned long crc32(const char *s)
  {
  	return partial_crc32(s, 0xffffffff) ^ 0xffffffff;
  }
  
  /*----------------------------------------------------------------------*/
  
  static enum symbol_type map_to_ns(enum symbol_type t)
  {
  	switch (t) {
  	case SYM_ENUM_CONST:
  	case SYM_NORMAL:
  	case SYM_TYPEDEF:
  		return SYM_NORMAL;
  	case SYM_ENUM:
  	case SYM_STRUCT:
  	case SYM_UNION:
  		return SYM_STRUCT;
  	}
  	return t;
  }
  
  struct symbol *find_symbol(const char *name, enum symbol_type ns, int exact)
  {
  	unsigned long h = crc32(name) % HASH_BUCKETS;
  	struct symbol *sym;
  
  	for (sym = symtab[h]; sym; sym = sym->hash_next)
  		if (map_to_ns(sym->type) == map_to_ns(ns) &&
  		    strcmp(name, sym->name) == 0 &&
  		    sym->is_declared)
  			break;
  
  	if (exact && sym && sym->type != ns)
  		return NULL;
  	return sym;
  }
  
  static int is_unknown_symbol(struct symbol *sym)
  {
  	struct string_list *defn;
  
  	return ((sym->type == SYM_STRUCT ||
  		 sym->type == SYM_UNION ||
  		 sym->type == SYM_ENUM) &&
  		(defn = sym->defn)  && defn->tag == SYM_NORMAL &&
  			strcmp(defn->string, "}") == 0 &&
  		(defn = defn->next) && defn->tag == SYM_NORMAL &&
  			strcmp(defn->string, "UNKNOWN") == 0 &&
  		(defn = defn->next) && defn->tag == SYM_NORMAL &&
  			strcmp(defn->string, "{") == 0);
  }
  
  static struct symbol *__add_symbol(const char *name, enum symbol_type type,
  			    struct string_list *defn, int is_extern,
  			    int is_reference)
  {
  	unsigned long h;
  	struct symbol *sym;
  	enum symbol_status status = STATUS_UNCHANGED;
  	/* The parser adds symbols in the order their declaration completes,
  	 * so it is safe to store the value of the previous enum constant in
  	 * a static variable.
  	 */
  	static int enum_counter;
  	static struct string_list *last_enum_expr;
  
  	if (type == SYM_ENUM_CONST) {
  		if (defn) {
  			free_list(last_enum_expr, NULL);
  			last_enum_expr = copy_list_range(defn, NULL);
  			enum_counter = 1;
  		} else {
  			struct string_list *expr;
  			char buf[20];
  
  			snprintf(buf, sizeof(buf), "%d", enum_counter++);
  			if (last_enum_expr) {
  				expr = copy_list_range(last_enum_expr, NULL);
  				defn = concat_list(mk_node("("),
  						   expr,
  						   mk_node(")"),
  						   mk_node("+"),
  						   mk_node(buf), NULL);
  			} else {
  				defn = mk_node(buf);
  			}
  		}
  	} else if (type == SYM_ENUM) {
  		free_list(last_enum_expr, NULL);
  		last_enum_expr = NULL;
  		enum_counter = 0;
  		if (!name)
  			/* Anonymous enum definition, nothing more to do */
  			return NULL;
  	}
  
  	h = crc32(name) % HASH_BUCKETS;
  	for (sym = symtab[h]; sym; sym = sym->hash_next) {
  		if (map_to_ns(sym->type) == map_to_ns(type) &&
  		    strcmp(name, sym->name) == 0) {
  			if (is_reference)
  				/* fall through */ ;
  			else if (sym->type == type &&
  				 equal_list(sym->defn, defn)) {
  				if (!sym->is_declared && sym->is_override) {
  					print_location();
  					print_type_name(type, name);
  					fprintf(stderr, " modversion is "
  						"unchanged
  ");
  				}
  				sym->is_declared = 1;
  				return sym;
  			} else if (!sym->is_declared) {
  				if (sym->is_override && flag_preserve) {
  					print_location();
  					fprintf(stderr, "ignoring ");
  					print_type_name(type, name);
  					fprintf(stderr, " modversion change
  ");
  					sym->is_declared = 1;
  					return sym;
  				} else {
  					status = is_unknown_symbol(sym) ?
  						STATUS_DEFINED : STATUS_MODIFIED;
  				}
  			} else {
  				error_with_pos("redefinition of %s", name);
  				return sym;
  			}
  			break;
  		}
  	}
  
  	if (sym) {
  		struct symbol **psym;
  
  		for (psym = &symtab[h]; *psym; psym = &(*psym)->hash_next) {
  			if (*psym == sym) {
  				*psym = sym->hash_next;
  				break;
  			}
  		}
  		--nsyms;
  	}
  
  	sym = xmalloc(sizeof(*sym));
  	sym->name = name;
  	sym->type = type;
  	sym->defn = defn;
  	sym->expansion_trail = NULL;
  	sym->visited = NULL;
  	sym->is_extern = is_extern;
  
  	sym->hash_next = symtab[h];
  	symtab[h] = sym;
  
  	sym->is_declared = !is_reference;
  	sym->status = status;
  	sym->is_override = 0;
  
  	if (flag_debug) {
  		if (symbol_types[type].name)
  			fprintf(debugfile, "Defn for %s %s == <",
  				symbol_types[type].name, name);
  		else
  			fprintf(debugfile, "Defn for type%d %s == <",
  				type, name);
  		if (is_extern)
  			fputs("extern ", debugfile);
  		print_list(debugfile, defn);
  		fputs(">
  ", debugfile);
  	}
  
  	++nsyms;
  	return sym;
  }
  
  struct symbol *add_symbol(const char *name, enum symbol_type type,
  			  struct string_list *defn, int is_extern)
  {
  	return __add_symbol(name, type, defn, is_extern, 0);
  }
  
  static struct symbol *add_reference_symbol(const char *name, enum symbol_type type,
  				    struct string_list *defn, int is_extern)
  {
  	return __add_symbol(name, type, defn, is_extern, 1);
  }
  
  /*----------------------------------------------------------------------*/
  
  void free_node(struct string_list *node)
  {
  	free(node->string);
  	free(node);
  }
  
  void free_list(struct string_list *s, struct string_list *e)
  {
  	while (s != e) {
  		struct string_list *next = s->next;
  		free_node(s);
  		s = next;
  	}
  }
  
  static struct string_list *mk_node(const char *string)
  {
  	struct string_list *newnode;
  
  	newnode = xmalloc(sizeof(*newnode));
  	newnode->string = xstrdup(string);
  	newnode->tag = SYM_NORMAL;
  	newnode->next = NULL;
  
  	return newnode;
  }
  
  static struct string_list *concat_list(struct string_list *start, ...)
  {
  	va_list ap;
  	struct string_list *n, *n2;
  
  	if (!start)
  		return NULL;
  	for (va_start(ap, start); (n = va_arg(ap, struct string_list *));) {
  		for (n2 = n; n2->next; n2 = n2->next)
  			;
  		n2->next = start;
  		start = n;
  	}
  	va_end(ap);
  	return start;
  }
  
  struct string_list *copy_node(struct string_list *node)
  {
  	struct string_list *newnode;
  
  	newnode = xmalloc(sizeof(*newnode));
  	newnode->string = xstrdup(node->string);
  	newnode->tag = node->tag;
  
  	return newnode;
  }
  
  struct string_list *copy_list_range(struct string_list *start,
  				    struct string_list *end)
  {
  	struct string_list *res, *n;
  
  	if (start == end)
  		return NULL;
  	n = res = copy_node(start);
  	for (start = start->next; start != end; start = start->next) {
  		n->next = copy_node(start);
  		n = n->next;
  	}
  	n->next = NULL;
  	return res;
  }
  
  static int equal_list(struct string_list *a, struct string_list *b)
  {
  	while (a && b) {
  		if (a->tag != b->tag || strcmp(a->string, b->string))
  			return 0;
  		a = a->next;
  		b = b->next;
  	}
  
  	return !a && !b;
  }
  
  #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
  
  static struct string_list *read_node(FILE *f)
  {
  	char buffer[256];
  	struct string_list node = {
  		.string = buffer,
  		.tag = SYM_NORMAL };
  	int c;
  
  	while ((c = fgetc(f)) != EOF) {
  		if (c == ' ') {
  			if (node.string == buffer)
  				continue;
  			break;
  		} else if (c == '
  ') {
  			if (node.string == buffer)
  				return NULL;
  			ungetc(c, f);
  			break;
  		}
  		if (node.string >= buffer + sizeof(buffer) - 1) {
  			fprintf(stderr, "Token too long
  ");
  			exit(1);
  		}
  		*node.string++ = c;
  	}
  	if (node.string == buffer)
  		return NULL;
  	*node.string = 0;
  	node.string = buffer;
  
  	if (node.string[1] == '#') {
  		size_t n;
  
  		for (n = 0; n < ARRAY_SIZE(symbol_types); n++) {
  			if (node.string[0] == symbol_types[n].n) {
  				node.tag = n;
  				node.string += 2;
  				return copy_node(&node);
  			}
  		}
  		fprintf(stderr, "Unknown type %c
  ", node.string[0]);
  		exit(1);
  	}
  	return copy_node(&node);
  }
  
  static void read_reference(FILE *f)
  {
  	while (!feof(f)) {
  		struct string_list *defn = NULL;
  		struct string_list *sym, *def;
  		int is_extern = 0, is_override = 0;
  		struct symbol *subsym;
  
  		sym = read_node(f);
  		if (sym && sym->tag == SYM_NORMAL &&
  		    !strcmp(sym->string, "override")) {
  			is_override = 1;
  			free_node(sym);
  			sym = read_node(f);
  		}
  		if (!sym)
  			continue;
  		def = read_node(f);
  		if (def && def->tag == SYM_NORMAL &&
  		    !strcmp(def->string, "extern")) {
  			is_extern = 1;
  			free_node(def);
  			def = read_node(f);
  		}
  		while (def) {
  			def->next = defn;
  			defn = def;
  			def = read_node(f);
  		}
  		subsym = add_reference_symbol(xstrdup(sym->string), sym->tag,
  					      defn, is_extern);
  		subsym->is_override = is_override;
  		free_node(sym);
  	}
  }
  
  static void print_node(FILE * f, struct string_list *list)
  {
  	if (symbol_types[list->tag].n) {
  		putc(symbol_types[list->tag].n, f);
  		putc('#', f);
  	}
  	fputs(list->string, f);
  }
  
  static void print_list(FILE * f, struct string_list *list)
  {
  	struct string_list **e, **b;
  	struct string_list *tmp, **tmp2;
  	int elem = 1;
  
  	if (list == NULL) {
  		fputs("(nil)", f);
  		return;
  	}
  
  	tmp = list;
  	while ((tmp = tmp->next) != NULL)
  		elem++;
  
  	b = alloca(elem * sizeof(*e));
  	e = b + elem;
  	tmp2 = e - 1;
  
  	(*tmp2--) = list;
  	while ((list = list->next) != NULL)
  		*(tmp2--) = list;
  
  	while (b != e) {
  		print_node(f, *b++);
  		putc(' ', f);
  	}
  }
  
  static unsigned long expand_and_crc_sym(struct symbol *sym, unsigned long crc)
  {
  	struct string_list *list = sym->defn;
  	struct string_list **e, **b;
  	struct string_list *tmp, **tmp2;
  	int elem = 1;
  
  	if (!list)
  		return crc;
  
  	tmp = list;
  	while ((tmp = tmp->next) != NULL)
  		elem++;
  
  	b = alloca(elem * sizeof(*e));
  	e = b + elem;
  	tmp2 = e - 1;
  
  	*(tmp2--) = list;
  	while ((list = list->next) != NULL)
  		*(tmp2--) = list;
  
  	while (b != e) {
  		struct string_list *cur;
  		struct symbol *subsym;
  
  		cur = *(b++);
  		switch (cur->tag) {
  		case SYM_NORMAL:
  			if (flag_dump_defs)
  				fprintf(debugfile, "%s ", cur->string);
  			crc = partial_crc32(cur->string, crc);
  			crc = partial_crc32_one(' ', crc);
  			break;
  
  		case SYM_ENUM_CONST:
  		case SYM_TYPEDEF:
  			subsym = find_symbol(cur->string, cur->tag, 0);
  			/* FIXME: Bad reference files can segfault here. */
  			if (subsym->expansion_trail) {
  				if (flag_dump_defs)
  					fprintf(debugfile, "%s ", cur->string);
  				crc = partial_crc32(cur->string, crc);
  				crc = partial_crc32_one(' ', crc);
  			} else {
  				subsym->expansion_trail = expansion_trail;
  				expansion_trail = subsym;
  				crc = expand_and_crc_sym(subsym, crc);
  			}
  			break;
  
  		case SYM_STRUCT:
  		case SYM_UNION:
  		case SYM_ENUM:
  			subsym = find_symbol(cur->string, cur->tag, 0);
  			if (!subsym) {
  				struct string_list *n;
  
  				error_with_pos("expand undefined %s %s",
  					       symbol_types[cur->tag].name,
  					       cur->string);
  				n = concat_list(mk_node
  						(symbol_types[cur->tag].name),
  						mk_node(cur->string),
  						mk_node("{"),
  						mk_node("UNKNOWN"),
  						mk_node("}"), NULL);
  				subsym =
  				    add_symbol(cur->string, cur->tag, n, 0);
  			}
  			if (subsym->expansion_trail) {
  				if (flag_dump_defs) {
  					fprintf(debugfile, "%s %s ",
  						symbol_types[cur->tag].name,
  						cur->string);
  				}
  
  				crc = partial_crc32(symbol_types[cur->tag].name,
  						    crc);
  				crc = partial_crc32_one(' ', crc);
  				crc = partial_crc32(cur->string, crc);
  				crc = partial_crc32_one(' ', crc);
  			} else {
  				subsym->expansion_trail = expansion_trail;
  				expansion_trail = subsym;
  				crc = expand_and_crc_sym(subsym, crc);
  			}
  			break;
  		}
  	}
  
  	{
  		static struct symbol **end = &visited_symbols;
  
  		if (!sym->visited) {
  			*end = sym;
  			end = &sym->visited;
  			sym->visited = (struct symbol *)-1L;
  		}
  	}
  
  	return crc;
  }
  
  void export_symbol(const char *name)
  {
  	struct symbol *sym;
  
  	sym = find_symbol(name, SYM_NORMAL, 0);
  	if (!sym)
  		error_with_pos("export undefined symbol %s", name);
  	else {
  		unsigned long crc;
  		int has_changed = 0;
  
  		if (flag_dump_defs)
  			fprintf(debugfile, "Export %s == <", name);
  
  		expansion_trail = (struct symbol *)-1L;
  
  		sym->expansion_trail = expansion_trail;
  		expansion_trail = sym;
  		crc = expand_and_crc_sym(sym, 0xffffffff) ^ 0xffffffff;
  
  		sym = expansion_trail;
  		while (sym != (struct symbol *)-1L) {
  			struct symbol *n = sym->expansion_trail;
  
  			if (sym->status != STATUS_UNCHANGED) {
  				if (!has_changed) {
  					print_location();
  					fprintf(stderr, "%s: %s: modversion "
  						"changed because of changes "
  						"in ", flag_preserve ? "error" :
  						       "warning", name);
  				} else
  					fprintf(stderr, ", ");
  				print_type_name(sym->type, sym->name);
  				if (sym->status == STATUS_DEFINED)
  					fprintf(stderr, " (became defined)");
  				has_changed = 1;
  				if (flag_preserve)
  					errors++;
  			}
  			sym->expansion_trail = 0;
  			sym = n;
  		}
  		if (has_changed)
  			fprintf(stderr, "
  ");
  
  		if (flag_dump_defs)
  			fputs(">
  ", debugfile);
  
  		/* Used as a linker script. */
  		printf("%s__crc_%s = 0x%08lx ;
  ", mod_prefix, name, crc);
  	}
  }
  
  /*----------------------------------------------------------------------*/
  
  static void print_location(void)
  {
  	fprintf(stderr, "%s:%d: ", cur_filename ? : "<stdin>", cur_line);
  }
  
  static void print_type_name(enum symbol_type type, const char *name)
  {
  	if (symbol_types[type].name)
  		fprintf(stderr, "%s %s", symbol_types[type].name, name);
  	else
  		fprintf(stderr, "%s", name);
  }
  
  void error_with_pos(const char *fmt, ...)
  {
  	va_list args;
  
  	if (flag_warnings) {
  		print_location();
  
  		va_start(args, fmt);
  		vfprintf(stderr, fmt, args);
  		va_end(args);
  		putc('
  ', stderr);
  
  		errors++;
  	}
  }
  
  static void genksyms_usage(void)
  {
  	fputs("Usage:
  " "genksyms [-adDTwqhV] > /path/to/.tmp_obj.ver
  " "
  "
  #ifdef __GNU_LIBRARY__
  	      "  -s, --symbol-prefix   Select symbol prefix
  "
  	      "  -d, --debug           Increment the debug level (repeatable)
  "
  	      "  -D, --dump            Dump expanded symbol defs (for debugging only)
  "
  	      "  -r, --reference file  Read reference symbols from a file
  "
  	      "  -T, --dump-types file Dump expanded types into file
  "
  	      "  -p, --preserve        Preserve reference modversions or fail
  "
  	      "  -w, --warnings        Enable warnings
  "
  	      "  -q, --quiet           Disable warnings (default)
  "
  	      "  -h, --help            Print this message
  "
  	      "  -V, --version         Print the release version
  "
  #else				/* __GNU_LIBRARY__ */
  	      "  -s                    Select symbol prefix
  "
  	      "  -d                    Increment the debug level (repeatable)
  "
  	      "  -D                    Dump expanded symbol defs (for debugging only)
  "
  	      "  -r file               Read reference symbols from a file
  "
  	      "  -T file               Dump expanded types into file
  "
  	      "  -p                    Preserve reference modversions or fail
  "
  	      "  -w                    Enable warnings
  "
  	      "  -q                    Disable warnings (default)
  "
  	      "  -h                    Print this message
  "
  	      "  -V                    Print the release version
  "
  #endif				/* __GNU_LIBRARY__ */
  	      , stderr);
  }
  
  int main(int argc, char **argv)
  {
  	FILE *dumpfile = NULL, *ref_file = NULL;
  	int o;
  
  #ifdef __GNU_LIBRARY__
  	struct option long_opts[] = {
  		{"symbol-prefix", 1, 0, 's'},
  		{"debug", 0, 0, 'd'},
  		{"warnings", 0, 0, 'w'},
  		{"quiet", 0, 0, 'q'},
  		{"dump", 0, 0, 'D'},
  		{"reference", 1, 0, 'r'},
  		{"dump-types", 1, 0, 'T'},
  		{"preserve", 0, 0, 'p'},
  		{"version", 0, 0, 'V'},
  		{"help", 0, 0, 'h'},
  		{0, 0, 0, 0}
  	};
  
  	while ((o = getopt_long(argc, argv, "s:dwqVDr:T:ph",
  				&long_opts[0], NULL)) != EOF)
  #else				/* __GNU_LIBRARY__ */
  	while ((o = getopt(argc, argv, "s:dwqVDr:T:ph")) != EOF)
  #endif				/* __GNU_LIBRARY__ */
  		switch (o) {
  		case 's':
  			mod_prefix = optarg;
  			break;
  		case 'd':
  			flag_debug++;
  			break;
  		case 'w':
  			flag_warnings = 1;
  			break;
  		case 'q':
  			flag_warnings = 0;
  			break;
  		case 'V':
  			fputs("genksyms version 2.5.60
  ", stderr);
  			break;
  		case 'D':
  			flag_dump_defs = 1;
  			break;
  		case 'r':
  			flag_reference = 1;
  			ref_file = fopen(optarg, "r");
  			if (!ref_file) {
  				perror(optarg);
  				return 1;
  			}
  			break;
  		case 'T':
  			flag_dump_types = 1;
  			dumpfile = fopen(optarg, "w");
  			if (!dumpfile) {
  				perror(optarg);
  				return 1;
  			}
  			break;
  		case 'p':
  			flag_preserve = 1;
  			break;
  		case 'h':
  			genksyms_usage();
  			return 0;
  		default:
  			genksyms_usage();
  			return 1;
  		}
  	{
  		extern int yydebug;
  		extern int yy_flex_debug;
  
  		yydebug = (flag_debug > 1);
  		yy_flex_debug = (flag_debug > 2);
  
  		debugfile = stderr;
  		/* setlinebuf(debugfile); */
  	}
  
  	if (flag_reference) {
  		read_reference(ref_file);
  		fclose(ref_file);
  	}
  
  	yyparse();
  
  	if (flag_dump_types && visited_symbols) {
  		while (visited_symbols != (struct symbol *)-1L) {
  			struct symbol *sym = visited_symbols;
  
  			if (sym->is_override)
  				fputs("override ", dumpfile);
  			if (symbol_types[sym->type].n) {
  				putc(symbol_types[sym->type].n, dumpfile);
  				putc('#', dumpfile);
  			}
  			fputs(sym->name, dumpfile);
  			putc(' ', dumpfile);
  			if (sym->is_extern)
  				fputs("extern ", dumpfile);
  			print_list(dumpfile, sym->defn);
  			putc('
  ', dumpfile);
  
  			visited_symbols = sym->visited;
  			sym->visited = NULL;
  		}
  	}
  
  	if (flag_debug) {
  		fprintf(debugfile, "Hash table occupancy %d/%d = %g
  ",
  			nsyms, HASH_BUCKETS,
  			(double)nsyms / (double)HASH_BUCKETS);
  	}
  
  	return errors != 0;
  }