/* 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;

static int flag_debug, flag_dump_defs, flag_dump_types, flag_warnings;
static const char *arch = "";
static const char *mod_prefix = "";

static int errors;
static int nsyms;

static struct symbol *expansion_trail;
static struct symbol *visited_symbols;

static const char *const symbol_type_name[] = {
	"normal", "typedef", "enum", "struct", "union"
};

static int equal_list(struct string_list *a, struct string_list *b);
static void print_list(FILE * f, struct string_list *list);

/*----------------------------------------------------------------------*/

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)
{
	if (t == SYM_TYPEDEF)
		t = SYM_NORMAL;
	else if (t == SYM_UNION)
		t = SYM_STRUCT;
	return t;
}

struct symbol *find_symbol(const char *name, enum symbol_type ns)
{
	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)
			break;

	return sym;
}

struct symbol *add_symbol(const char *name, enum symbol_type type,
			  struct string_list *defn, int is_extern)
{
	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(type)
		    && strcmp(name, sym->name) == 0) {
			if (!equal_list(sym->defn, defn))
				error_with_pos("redefinition of %s", name);
			return sym;
		}
	}

	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;

	if (flag_debug) {
		fprintf(debugfile, "Defn for %s %s == <",
			symbol_type_name[type], name);
		if (is_extern)
			fputs("extern ", debugfile);
		print_list(debugfile, defn);
		fputs(">\n", debugfile);
	}

	++nsyms;
	return sym;
}

/*----------------------------------------------------------------------*/

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;
	}
}

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;
}

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;
}

static void print_node(FILE * f, struct string_list *list)
{
	if (list->tag != SYM_NORMAL) {
		putc(symbol_type_name[list->tag][0], 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_TYPEDEF:
			subsym = find_symbol(cur->string, cur->tag);
			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);
			if (!subsym) {
				struct string_list *n, *t = NULL;

				error_with_pos("expand undefined %s %s",
					       symbol_type_name[cur->tag],
					       cur->string);

				n = xmalloc(sizeof(*n));
				n->string = xstrdup(symbol_type_name[cur->tag]);
				n->tag = SYM_NORMAL;
				n->next = t;
				t = n;

				n = xmalloc(sizeof(*n));
				n->string = xstrdup(cur->string);
				n->tag = SYM_NORMAL;
				n->next = t;
				t = n;

				n = xmalloc(sizeof(*n));
				n->string = xstrdup("{ UNKNOWN }");
				n->tag = SYM_NORMAL;
				n->next = t;

				subsym =
				    add_symbol(cur->string, cur->tag, n, 0);
			}
			if (subsym->expansion_trail) {
				if (flag_dump_defs) {
					fprintf(debugfile, "%s %s ",
						symbol_type_name[cur->tag],
						cur->string);
				}

				crc = partial_crc32(symbol_type_name[cur->tag],
						    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);
	if (!sym)
		error_with_pos("export undefined symbol %s", name);
	else {
		unsigned long crc;

		if (flag_dump_defs)
			fprintf(debugfile, "Export %s == <", name);

		expansion_trail = (struct symbol *)-1L;

		crc = expand_and_crc_sym(sym, 0xffffffff) ^ 0xffffffff;

		sym = expansion_trail;
		while (sym != (struct symbol *)-1L) {
			struct symbol *n = sym->expansion_trail;
			sym->expansion_trail = 0;
			sym = n;
		}

		if (flag_dump_defs)
			fputs(">\n", debugfile);

		/* Used as a linker script. */
		printf("%s__crc_%s = 0x%08lx ;\n", mod_prefix, name, crc);
	}
}

/*----------------------------------------------------------------------*/
void error_with_pos(const char *fmt, ...)
{
	va_list args;

	if (flag_warnings) {
		fprintf(stderr, "%s:%d: ", cur_filename ? : "<stdin>",
			cur_line);

		va_start(args, fmt);
		vfprintf(stderr, fmt, args);
		va_end(args);
		putc('\n', stderr);

		errors++;
	}
}

static void genksyms_usage(void)
{
	fputs("Usage:\n" "genksyms [-dDwqhV] > /path/to/.tmp_obj.ver\n" "\n"
#ifdef __GNU_LIBRARY__
	      "  -d, --debug           Increment the debug level (repeatable)\n"
	      "  -D, --dump            Dump expanded symbol defs (for debugging only)\n"
	      "  -w, --warnings        Enable warnings\n"
	      "  -q, --quiet           Disable warnings (default)\n"
	      "  -h, --help            Print this message\n"
	      "  -V, --version         Print the release version\n"
#else				/* __GNU_LIBRARY__ */
	      "  -d                    Increment the debug level (repeatable)\n"
	      "  -D                    Dump expanded symbol defs (for debugging only)\n"
	      "  -w                    Enable warnings\n"
	      "  -q                    Disable warnings (default)\n"
	      "  -h                    Print this message\n"
	      "  -V                    Print the release version\n"
#endif				/* __GNU_LIBRARY__ */
	      , stderr);
}

int main(int argc, char **argv)
{
	FILE *dumpfile = NULL;
	int o;

#ifdef __GNU_LIBRARY__
	struct option long_opts[] = {
		{"arch", 1, 0, 'a'},
		{"debug", 0, 0, 'd'},
		{"warnings", 0, 0, 'w'},
		{"quiet", 0, 0, 'q'},
		{"dump", 0, 0, 'D'},
		{"dump-types", 1, 0, 'T'},
		{"version", 0, 0, 'V'},
		{"help", 0, 0, 'h'},
		{0, 0, 0, 0}
	};

	while ((o = getopt_long(argc, argv, "a:dwqVDT:k:p:",
				&long_opts[0], NULL)) != EOF)
#else				/* __GNU_LIBRARY__ */
	while ((o = getopt(argc, argv, "a:dwqVDT:k:p:")) != EOF)
#endif				/* __GNU_LIBRARY__ */
		switch (o) {
		case 'a':
			arch = 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\n", stderr);
			break;
		case 'D':
			flag_dump_defs = 1;
			break;
		case 'T':
			flag_dump_types = 1;
			dumpfile = fopen(optarg, "w");
			if (!dumpfile) {
				perror(optarg);
				return 1;
			}
			break;
		case 'h':
			genksyms_usage();
			return 0;
		default:
			genksyms_usage();
			return 1;
		}
	if ((strcmp(arch, "v850") == 0) || (strcmp(arch, "h8300") == 0)
	    || (strcmp(arch, "blackfin") == 0))
		mod_prefix = "_";
	{
		extern int yydebug;
		extern int yy_flex_debug;

		yydebug = (flag_debug > 1);
		yy_flex_debug = (flag_debug > 2);

		debugfile = stderr;
		/* setlinebuf(debugfile); */
	}

	yyparse();

	if (flag_dump_types && visited_symbols) {
		while (visited_symbols != (struct symbol *)-1L) {
			struct symbol *sym = visited_symbols;

			if (sym->type != SYM_NORMAL) {
				putc(symbol_type_name[sym->type][0], dumpfile);
				putc('#', dumpfile);
			}
			fputs(sym->name, dumpfile);
			putc(' ', dumpfile);
			print_list(dumpfile, sym->defn);
			putc('\n', dumpfile);

			visited_symbols = sym->visited;
			sym->visited = NULL;
		}
	}

	if (flag_debug) {
		fprintf(debugfile, "Hash table occupancy %d/%d = %g\n",
			nsyms, HASH_BUCKETS,
			(double)nsyms / (double)HASH_BUCKETS);
	}

	return errors != 0;
}
