/* Copyright (C) 2001 DJ Delorie, see COPYING.DJ for details */
/* Copyright (C) 1999 DJ Delorie, see COPYING.DJ for details */
/* Copyright (C) 1998 DJ Delorie, see COPYING.DJ for details */
/* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
%{

#define YYDEBUG 1
  
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <fcntl.h>
#include <time.h>
#include <ctype.h>
#include <unistd.h>
#ifndef O_BINARY
#define O_BINARY 0
#endif
#undef _POSIX_SOURCE
#include "../../include/coff.h"

#define SMALL_EXE_HEADER 0
#if SMALL_EXE_HEADER
#define EXE_HEADER_SIZE 32
#define EXE_HEADER_BLOCKS 1
#else
#define EXE_HEADER_SIZE 512
#define EXE_HEADER_BLOCKS 32
#endif

#define YYERROR_VERBOSE

#define MAX(a,b) ((a)>(b)?(a):(b))
#define MIN(a,b) ((a)<(b)?(a):(b))

void djerror(char *s);
void yyerror(char *s);
void shxd_error(int opcode);

#define OUT_exe 0
#define OUT_com 1
#define OUT_bin 2
#define OUT_h   3
#define OUT_inc 4
#define OUT_s   5
#define OUT_sys 6
#define OUT_obj 7

char *ext_types[] = {
  "exe",
  "com",
  "bin",
  "h",
  "inc",
  "ah",
  "sys",
  "obj",
  0
};

char *INC_LEADER = "\t.db\t";
char *S_LEADER = "\t.byte\t";

int out_type = OUT_exe;
int image_type = OUT_exe;
char *outname = 0;

int i;
int lineno = 1;
char *inname;
int total_errors = 0;
char last_token[100];
int last_tret;
char *copyright = 0;

int last_align_begin=-1, last_align_end=-1;
int generated_bytes = -1;

char strbuf[200];
int strbuflen;

typedef struct {
  unsigned short line;
  unsigned short addr;
  char *name;
} lineaddr_s;

lineaddr_s *lineaddr=0;
int num_lineaddr=0;
int max_lineaddr=0;

unsigned char *outbin = 0;
int outsize = 0;
int pc = 0;
int bsspc = -1;
int stack_ptr = 0;
int start_ptr = 0;
int movacc = 0;
int main_obj = 1;

typedef struct Symbol {
  struct Symbol *next;
  char *name;
  int value;
  unsigned defined:1;
  unsigned external:1;
  unsigned public:1;
  struct Patch *patches;
  int first_used;
  int type;
} Symbol;

#define SYM_unknown	0
#define SYM_abs		1
#define SYM_data	2
#define SYM_code	4
#define SYMTYPES "?ADDTTTT"

Symbol pc_symbol = {0,".",0,1,0,0,0,0,SYM_code};

#define REL_abs		0
#define REL_abs32	1
#define REL_16		2
#define REL_8		3
#define REL_abs8	4

typedef struct Patch {
  struct Patch *next;
  int location;
  int lineno;
  char *filename;
  int rel;
} Patch;

Symbol *symtab = 0;
Symbol *get_symbol(char *name, int create);
Symbol *set_symbol(Symbol *sym, int value);
Symbol *zerosym;
int undefs = 0;

void destroy_symbol(Symbol *sym, int undef_error);
void destroy_locals(void);
void add_enum_element(Symbol *s);
void add_struct_element(Symbol *s);
void emit_struct(Symbol *ele, int tp, Symbol *struc);
void emit_struct_abs(Symbol *ele, int tp, Symbol *struc, int offset);
void build_struct(Symbol *ele, int tp, Symbol *struc);

struct {
  int regs;
  int offset;
  int addr16;
  int addr32;
  int nsyms;
  Symbol *syms[10];
} _modrm = { 0, 0, 0, 0, 0 };

unsigned char sreg_overrides[] = {
  0x26, 0x2e, 0x36, 0x3e, 0x64, 0x65
};

int struct_tp;
int struct_pc;
char *struct_sym;

int yylex(void);
int yylex1(void);

void emit(void *v, int len);
void emitb(int b);
void emitw(int w);
void emitd(long d);
void emits(Symbol *s, int offset, int rel);
void modrm(int mod, int reg, int rm);
void reg(int reg);
void addr32(int sib);
void sortsyms();

int istemp(char *symname, char which);
int islocal(char *symname);
void do_sreg_pop(int sreg);
void do_sreg_push(int sreg);
void do_align(int p2, int val);
void set_lineaddr();
void add_copyright(char *buf);
void add_rcs_ident(char *buf);

void set_out_type(char *type);
void set_image_type(char *type);
void do_include(char *fname);
void do_linkcoff(char *fname);

void write_THEADR(FILE *outfile, char *inname);
void write_LNAMES(FILE *outfile, ...);
void write_SEGDEF(FILE *outfile, int size, int name, int class, int overlay);
void write_EXTDEF(FILE *outfile, Symbol *symtab);
void write_PUBDEF(FILE *outfile, Symbol *symtab, int bss_start);
void write_LEDATA(FILE *outfile, int segment, unsigned char *outbin, int size,
		  Symbol *symtab);
void write_MODEND(FILE *outfile, int main_obj, int start_ptr);

%}

%expect 2 /* see regmem */

%union {
  Symbol *sym;
  int i;
  struct {
    Symbol *sym;
    int ofs;
  } relsym;
}

%type <sym> ID
%type <relsym> constID
%type <i> const offset scaledindex

%token <sym> KID UID

%left OP_OR '|' '^'
%left OP_AND '&'
%nonassoc '=' '<' '>' OP_NE OP_LE OP_GE
%left OP_SHL OP_SHR
%left '+' '-'
%left '*' '/' '%'
%left OP_NEG OP_LNOT OP_NOT

%token <i> NUMBER REG8 REG16 REG32 SREG STRING PC CRREG DRREG TRREG
%token <i> ARITH2 ARITH2B ARITH2D ARITH2W
%token <i> LXS MOVSZX MOVSZXB MOVSZXW
%token <i> JCC JCCL JCXZ LOOP SETCC
%token <i> SHIFT SHIFTB SHIFTD SHIFTW DPSHIFT
%token <i> ONEBYTE TWOBYTE ASCADJ
%token <i> BITTEST GROUP3 GROUP3B GROUP3D GROUP3W GROUP6 GROUP7 STRUCT
%token ALIGN ARPL
%token BOUND BSS BSF BSR
%token CALL CALLF CALLFD COPYRIGHT
%token DB DD DEC DECB DECD DECW DUP DW
%token ENDS ENUM ENTER
%token IN INC INCB INCD INCW INT INCLUDE
%token JMPW JMPB JMPF JMPFD
%token LAR LEA LINKCOFF LSL
%token MOV MOVB MOVD MOVW
%token IMUL IMULB IMULD IMULW
%token ORG OUT
%token POP POPW POPD PUSH PUSHW PUSHB PUSHD
%token RCS_ID RET RETF RETD RETFD
%token STACK START
%token TEST TESTB TESTD TESTW TYPE
%token XCHG

%{
#define NO_ATTR -1

struct opcode {
  char *name;
  int token;
  int attr;
};

struct opcode opcodes[] = {
  {"aaa", ONEBYTE, 0x37},
  {"aad", ASCADJ, 0xd5},
  {"aam", ASCADJ, 0xd4},
  {"aas", ONEBYTE, 0x3f},
  {"cbw", ONEBYTE, 0x98},
  {"cwde", TWOBYTE, 0x6698},
  {"clc", ONEBYTE, 0xf8},
  {"cld", ONEBYTE, 0xfc},
  {"cli", ONEBYTE, 0xfa},
  {"clts", TWOBYTE, 0x0f06},
  {"cmc", ONEBYTE, 0xf5},
  {"cmpsb", ONEBYTE, 0xa6},
  {"cmpsw", ONEBYTE, 0xa7},
  {"cmpsd", TWOBYTE, 0x66a7},
  {"cpuid", TWOBYTE, 0x0fa2},
  {"cwd", ONEBYTE, 0x99},
  {"cdq", TWOBYTE, 0x6699},
  {"daa", ONEBYTE, 0x27},
  {"das", ONEBYTE, 0x2f},
  {"hlt", ONEBYTE, 0xf4},
  {"insb", ONEBYTE, 0x6c},
  {"insw", ONEBYTE, 0x6d},
  {"insd", TWOBYTE, 0x666d},
  {"into", ONEBYTE, 0xce},
  {"iret", ONEBYTE, 0xcf},
  {"iretd", TWOBYTE, 0x66cf},
  {"lahf", ONEBYTE, 0x9f},
  {"leave", ONEBYTE, 0xc9},
  {"lock", ONEBYTE, 0xf0},
  {"lodsb", ONEBYTE, 0xac},
  {"lodsw", ONEBYTE, 0xad},
  {"lodsd", TWOBYTE, 0x66ad},
  {"movsb", ONEBYTE, 0xa4},
  {"movsw", ONEBYTE, 0xa5},
  {"movsd", TWOBYTE, 0x66a5},
  {"nop", ONEBYTE, 0x90},
  {"outsb", ONEBYTE, 0x6e},
  {"outsw", ONEBYTE, 0x6f},
  {"outsd", TWOBYTE, 0x666f},
  {"popa", ONEBYTE, 0x61},
  {"popad", TWOBYTE, 0x6661},
  {"popf", ONEBYTE, 0x9d},
  {"popfd", TWOBYTE, 0x669d},
  {"pusha", ONEBYTE, 0x60},
  {"pushad", TWOBYTE, 0x6660},
  {"pushf", ONEBYTE, 0x9c},
  {"pushfd", TWOBYTE, 0x669c},
  {"rep", ONEBYTE, 0xf3},
  {"repe", ONEBYTE, 0xf3},
  {"repz", ONEBYTE, 0xf3},
  {"repne", ONEBYTE, 0xf2},
  {"repnz", ONEBYTE, 0xf2},
  {"sahf", ONEBYTE, 0x9e},
  {"scasb", ONEBYTE, 0xae},
  {"scasw", ONEBYTE, 0xaf},
  {"scasd", TWOBYTE, 0x66af},
  {"stc", ONEBYTE, 0xf9},
  {"std", ONEBYTE, 0xfd},
  {"sti", ONEBYTE, 0xfb},
  {"stosb", ONEBYTE, 0xaa},
  {"stosw", ONEBYTE, 0xab},
  {"stosd", TWOBYTE, 0x66ab},
  {"wait", ONEBYTE, 0x9b},
  {"fwait", ONEBYTE, 0x9b},
  {"wbinvd", TWOBYTE, 0x0f09},
  {"xlat", ONEBYTE, 0xd7},
  {"xlatb", ONEBYTE, 0xd7},

  {".addrsize", ONEBYTE, 0x67},
  {".opsize", ONEBYTE, 0x66},
  {".segcs", ONEBYTE, 0x2e},
  {".segds", ONEBYTE, 0x3e},
  {".seges", ONEBYTE, 0x26},
  {".segss", ONEBYTE, 0x36},
  {".segfs", ONEBYTE, 0x64},
  {".seggs", ONEBYTE, 0x65},

  {".align", ALIGN, NO_ATTR},
  {".bss", BSS, NO_ATTR},
  {".copyright", COPYRIGHT, NO_ATTR},
  {".db", DB, NO_ATTR},
  {".dd", DD, NO_ATTR},
  {".dup", DUP, NO_ATTR},
  {".dw", DW, NO_ATTR},
  {".ends", ENDS, NO_ATTR},
  {".enum", ENUM, NO_ATTR},
  {".id", RCS_ID, NO_ATTR},
  {".include", INCLUDE, NO_ATTR},
  {".linkcoff", LINKCOFF, NO_ATTR},
  {".org", ORG, NO_ATTR},
  {".stack", STACK, NO_ATTR},
  {".start", START, NO_ATTR},
  {".struct", STRUCT, 's'},
  {".type", TYPE, NO_ATTR},
  {".union", STRUCT, 'u'},

  {"adc", ARITH2, 2},
  {"adcb", ARITH2B, 2},
  {"adcd", ARITH2D, 2},
  {"adcw", ARITH2W, 2},
  {"add", ARITH2, 0},
  {"addb", ARITH2B, 0},
  {"addd", ARITH2D, 0},
  {"addw", ARITH2W, 0},
  {"and", ARITH2, 4},
  {"andb", ARITH2B, 4},
  {"andd", ARITH2D, 4},
  {"andw", ARITH2W, 4},
  {"arpl", ARPL, NO_ATTR},
  {"bound", BOUND, NO_ATTR},
  {"bsf", BSF, NO_ATTR},
  {"bsr", BSR, NO_ATTR},
  {"bt", BITTEST, 4},
  {"btc", BITTEST, 7},
  {"btr", BITTEST, 6},
  {"bts", BITTEST, 5},
  {"call", CALL, NO_ATTR},
  {"callf", CALLF, NO_ATTR},
  {"callfd", CALLFD, NO_ATTR},
  {"cmp", ARITH2, 7},
  {"cmpb", ARITH2B, 7},
  {"cmpd", ARITH2D, 7},
  {"cmpw", ARITH2W, 7},
  {"dec", DEC, NO_ATTR},
  {"decb", DECB, NO_ATTR},
  {"decd", DECD, NO_ATTR},
  {"decw", DECW, NO_ATTR},
  {"div", GROUP3, 6},
  {"divb", GROUP3B, 6},
  {"divd", GROUP3D, 6},
  {"divw", GROUP3W, 6},
  {"enter", ENTER, NO_ATTR},
  {"idiv", GROUP3, 7},
  {"idivb", GROUP3B, 7},
  {"idivd", GROUP3D, 7},
  {"idivw", GROUP3W, 7},
  {"imul", IMUL, NO_ATTR},
  {"imulb", IMULB, NO_ATTR},
  {"imuld", IMULD, NO_ATTR},
  {"imulw", IMULW, NO_ATTR},
  {"in", IN, NO_ATTR},
  {"inc", INC, NO_ATTR},
  {"incb", INCB, NO_ATTR},
  {"incd", INCD, NO_ATTR},
  {"incw", INCW, NO_ATTR},
  {"int", INT, NO_ATTR},

  {"jo", JCC, 0},
  {"jno", JCC, 1},
  {"jb", JCC, 2},
  {"jc", JCC, 2},
  {"jnae", JCC, 2},
  {"jnb", JCC, 3},
  {"jnc", JCC, 3},
  {"jae", JCC, 3},
  {"jz", JCC, 4},
  {"je", JCC, 4},
  {"jnz", JCC, 5},
  {"jne", JCC, 5},
  {"jbe", JCC, 6},
  {"jna", JCC, 6},
  {"jnbe", JCC, 7},
  {"ja", JCC, 7},
  {"js", JCC, 8},
  {"jns", JCC, 9},
  {"jp", JCC, 10},
  {"jpe", JCC, 10},
  {"jnp", JCC, 11},
  {"jpo", JCC, 11},
  {"jl", JCC, 12},
  {"jnge", JCC, 12},
  {"jnl", JCC, 13},
  {"jge", JCC, 13},
  {"jle", JCC, 14},
  {"jng", JCC, 14},
  {"jnle", JCC, 15},
  {"jg", JCC, 15},

  {"jol", JCCL, 0},
  {"jnol", JCCL, 1},
  {"jbl", JCCL, 2},
  {"jcl", JCCL, 2},
  {"jnael", JCCL, 2},
  {"jnbl", JCCL, 3},
  {"jncl", JCCL, 3},
  {"jael", JCCL, 3},
  {"jzl", JCCL, 4},
  {"jel", JCCL, 4},
  {"jnzl", JCCL, 5},
  {"jnel", JCCL, 5},
  {"jbel", JCCL, 6},
  {"jnal", JCCL, 6},
  {"jnbel", JCCL, 7},
  {"jal", JCCL, 7},
  {"jsl", JCCL, 8},
  {"jnsl", JCCL, 9},
  {"jpl", JCCL, 10},
  {"jpel", JCCL, 10},
  {"jnpl", JCCL, 11},
  {"jpol", JCCL, 11},
  {"jll", JCCL, 12},
  {"jngel", JCCL, 12},
  {"jnll", JCCL, 13},
  {"jgel", JCCL, 13},
  {"jlel", JCCL, 14},
  {"jngl", JCCL, 14},
  {"jnlel", JCCL, 15},
  {"jgl", JCCL, 15},

  {"jcxz", JCXZ, 0},
  {"jecxz", JCXZ, 1},

  {"jmp", JMPB, NO_ATTR},
  {"jmpf", JMPF, NO_ATTR},
  {"jmpfd", JMPFD, NO_ATTR},
  {"jmpl", JMPW, NO_ATTR},
  {"lar", LAR, NO_ATTR},
  {"lds", LXS, 0xc5},
  {"lea", LEA, NO_ATTR},
  {"les", LXS, 0xc4},
  {"lfs", LXS, 0x0fb4},
  {"lgs", LXS, 0x0fb5},
  {"lsl", LSL, NO_ATTR},
  {"lss", LXS, 0x0fb2},
  {"lgdt", GROUP7, 2},
  {"lidt", GROUP7, 3},
  {"lldt", GROUP6, 2},
  {"lmsw", GROUP7, 6},
  {"loop", LOOP, 0xe2},
  {"loope", LOOP, 0xe1},
  {"loopne", LOOP, 0xe0},
  {"loopnz", LOOP, 0xe0},
  {"loopz", LOOP, 0xe1},
  {"ltr", GROUP6, 3},
  {"mov", MOV, NO_ATTR},
  {"movb", MOVB, NO_ATTR},
  {"movd", MOVD, NO_ATTR},
  {"movw", MOVW, NO_ATTR},
  {"movsx", MOVSZX, 0xbe},
  {"movsxb", MOVSZXB, 0xbe},
  {"movsxw", MOVSZXW, 0xbe},
  {"movzx", MOVSZX, 0xb6},
  {"movzxb", MOVSZXB, 0xb6},
  {"movzxw", MOVSZXW, 0xb6},
  {"mul", GROUP3, 4},
  {"mulb", GROUP3B, 4},
  {"muld", GROUP3D, 4},
  {"mulw", GROUP3W, 4},
  {"not", GROUP3, 2},
  {"neg", GROUP3, 3},
  {"or", ARITH2, 1},
  {"orb", ARITH2B, 1},
  {"ord", ARITH2D, 1},
  {"orw", ARITH2W, 1},
  {"out", OUT, NO_ATTR},
  {"pop", POP, NO_ATTR},
  {"popw", POPW, NO_ATTR},
  {"popd", POPD, NO_ATTR},
  {"push", PUSH, NO_ATTR},
  {"pushb", PUSHB, NO_ATTR},
  {"pushw", PUSHW, NO_ATTR},
  {"pushd", PUSHD, NO_ATTR},
  {"rcl", SHIFT, 2},
  {"rclb", SHIFTB, 2},
  {"rcld", SHIFTD, 2},
  {"rclw", SHIFTW, 2},
  {"rcr", SHIFT, 3},
  {"rcrb", SHIFTB, 3},
  {"rcrd", SHIFTD, 3},
  {"rcrw", SHIFTW, 3},
  {"ret", RET, NO_ATTR},
  {"retd", RETD, NO_ATTR},
  {"retf", RETF, NO_ATTR},
  {"retfd", RETFD, NO_ATTR},
  {"rol", SHIFT, 0},
  {"rolb", SHIFTB, 0},
  {"rold", SHIFTD, 0},
  {"rolw", SHIFTW, 0},
  {"ror", SHIFT, 1},
  {"rorb", SHIFTB, 1},
  {"rord", SHIFTD, 1},
  {"rorw", SHIFTW, 1},
  {"sar", SHIFT, 7},
  {"sarb", SHIFTB, 7},
  {"sard", SHIFTD, 7},
  {"sarw", SHIFTW, 7},
  {"sbb", ARITH2, 3},
  {"sbbb", ARITH2B, 3},
  {"sbbd", ARITH2D, 3},
  {"sbbw", ARITH2W, 3},

  {"seto", SETCC, 0},
  {"setno", SETCC, 1},
  {"setb", SETCC, 2},
  {"setc", SETCC, 2},
  {"setnae", SETCC, 2},
  {"setnb", SETCC, 3},
  {"setnc", SETCC, 3},
  {"setae", SETCC, 3},
  {"setz", SETCC, 4},
  {"sete", SETCC, 4},
  {"setnz", SETCC, 5},
  {"setne", SETCC, 5},
  {"setbe", SETCC, 6},
  {"setna", SETCC, 6},
  {"setnbe", SETCC, 7},
  {"seta", SETCC, 7},
  {"sets", SETCC, 8},
  {"setns", SETCC, 9},
  {"setp", SETCC, 10},
  {"setpe", SETCC, 10},
  {"setnp", SETCC, 11},
  {"setpo", SETCC, 11},
  {"setl", SETCC, 12},
  {"setnge", SETCC, 12},
  {"setnl", SETCC, 13},
  {"setge", SETCC, 13},
  {"setle", SETCC, 14},
  {"setng", SETCC, 14},
  {"setnle", SETCC, 15},
  {"setg", SETCC, 15},

  {"sgdt", GROUP7, 0},
  {"sidt", GROUP7, 1},
  {"sldt", GROUP6, 0},
  {"sal", SHIFT, 4},
  {"salb", SHIFTB, 4},
  {"sald", SHIFTD, 4},
  {"salw", SHIFTW, 4},
  {"shl", SHIFT, 4},
  {"shlb", SHIFTB, 4},
  {"shld", SHIFTD, 4},
  {"shlw", SHIFTW, 4},
  {"dshl", DPSHIFT, 0xa4},
  {"shr", SHIFT, 5},
  {"shrb", SHIFTB, 5},
  {"shrd", SHIFTD, 5},
  {"shrw", SHIFTW, 5},
  {"dshr", DPSHIFT, 0xac},
  {"smsw", GROUP7, 4},
  {"str", GROUP6, 1},
  {"sub", ARITH2, 5},
  {"subb", ARITH2B, 5},
  {"subd", ARITH2D, 5},
  {"subw", ARITH2W, 5},
  {"test", TEST, NO_ATTR},
  {"testb", TESTB, NO_ATTR},
  {"testw", TESTW, NO_ATTR},
  {"testd", TESTD, NO_ATTR},
  {"verr", GROUP6, 4},
  {"verw", GROUP6, 5},
  {"xchg", XCHG, NO_ATTR},
  {"xor", ARITH2, 6},
  {"xorb", ARITH2B, 6},
  {"xord", ARITH2D, 6},
  {"xorw", ARITH2W, 6},

  {"al", REG8, 0},
  {"cl", REG8, 1},
  {"dl", REG8, 2},
  {"bl", REG8, 3},
  {"ah", REG8, 4},
  {"ch", REG8, 5},
  {"dh", REG8, 6},
  {"bh", REG8, 7},

  {"es", SREG, 0},
  {"cs", SREG, 1},
  {"ss", SREG, 2},
  {"ds", SREG, 3},
  {"fs", SREG, 4},
  {"gs", SREG, 5},

  {"ax", REG16, 0},
  {"cx", REG16, 1},
  {"dx", REG16, 2},
  {"bx", REG16, 3},
  {"sp", REG16, 4},
  {"bp", REG16, 5},
  {"si", REG16, 6},
  {"di", REG16, 7},

  {"eax", REG32, 0},
  {"ecx", REG32, 1},
  {"edx", REG32, 2},
  {"ebx", REG32, 3},
  {"esp", REG32, 4},
  {"ebp", REG32, 5},
  {"esi", REG32, 6},
  {"edi", REG32, 7},

  {"cr0", CRREG, 0},
  {"cr2", CRREG, 2},
  {"cr3", CRREG, 3},

  {"dr0", DRREG, 0},
  {"dr1", DRREG, 1},
  {"dr2", DRREG, 2},
  {"dr3", DRREG, 3},
  {"dr6", DRREG, 6},
  {"dr7", DRREG, 7},

  {"tr3", TRREG, 3},
  {"tr4", TRREG, 4},
  {"tr5", TRREG, 5},
  {"tr6", TRREG, 6},
  {"tr7", TRREG, 7},
};
%}

%start lines

%% /***********************************************************************/

lines
	:
	| lines line '\n'		{ lineno++; pc_symbol.value=pc; }
	| lines INCLUDE STRING '\n'	{ strbuf[strbuflen]=0; do_include(strbuf); }
	| lines INCLUDE NUMBER '\n'	{ strbuf[strbuflen]=0; do_include(strbuf); }
	;

line
	:

	| ID ':'			{ set_symbol($1, pc)->type |= (pc?SYM_data:SYM_code); }
	| ID '=' const			{ set_symbol($1, $3)->type = SYM_abs; }
	| STRUCT ID '\n'		{ struct_pc=0;
					  struct_tp=$1;
					  struct_sym=$2->name;
					  lineno++;
					  $<sym>$=symtab;
					  symtab=symtab->next;
					}
	  struct_lines
	  ENDS				{ set_symbol($2, struct_pc)->type = SYM_abs;
					  $<sym>4->next=symtab;
					  symtab=$<sym>4;
	  				}
	| ENUM ID '\n'			{ struct_pc=0;
					  struct_sym=$2->name;
					  lineno++;
					  $<sym>$=symtab;
					  if (symtab==$2)
					      symtab=symtab->next;
					}
	  enum_lines
	  ENDS
	| ID STRUCT ID			{ emit_struct($1,$2,$3); }
	| ID STRUCT ID '(' const ')'	{ emit_struct_abs($1,$2,$3,$5); }
	| error

	| ONEBYTE			{ emitb($1); }
	| TWOBYTE			{ emitb($1>>8); emitb($1 & 0xff); }

	| BSS				{ bsspc = pc; generated_bytes = last_align_end == pc ? last_align_begin : pc; }

	| SREG ':'			{ emitb(sreg_overrides[$1]); }

	| ARITH2B regmem ',' const	{ emitb(0x80), reg($1); emitb($4); }
	| ARITH2 REG8 ',' const		{ if ($2)
					      {emitb(0x80), modrm(3, $1, $2);}
					  else
					      modrm (0,$1,4); 
					  emitb	($4);
					}
	| ARITH2 REG8 ',' REG8		{ emitb($1*8); modrm(3, $4, $2); }
	| ARITH2 regmem ',' REG8	{ emitb($1*8); reg($4); }
	| ARITH2 REG8 ',' regmem	{ emitb($1*8+2); reg($2); }

	| ARITH2W regmem ',' constID	{ emitb(0x81); reg($1); emits($4.sym,$4.ofs,REL_abs); }
	| ARITH2 REG16 ',' constID	{ if ($2) {
					      int v=$4.ofs+$4.sym->value;
					      if ($4.sym->defined && v>=-128 && v<=127) {
						  emitb(0x83); modrm(3, $1, $2);
						  emits($4.sym,$4.ofs,REL_abs8);
					      } else {
						  emitb(0x81); modrm(3, $1, $2);
						  emits($4.sym,$4.ofs,REL_abs);
					      }
					  } else {
					      modrm (0,$1,5);
					      emits($4.sym,$4.ofs,REL_abs);
					  }
					}
	| ARITH2 REG16 ',' REG16	{ emitb($1*8+1); modrm(3, $4, $2); }
	| ARITH2 regmem ',' REG16	{ emitb($1*8+1); reg($4); }
	| ARITH2 REG16 ',' regmem	{ emitb($1*8+3); reg($2); }

	| ARITH2D regmem ',' constID	{ emitb(0x66); emitb(0x81); reg($1); emits($4.sym,$4.ofs,REL_abs32); }
	| ARITH2 REG32 ',' constID	{ emitb(0x66);
					  if ($2) {
					      int v=$4.ofs+$4.sym->value;
					      if ($4.sym->defined && v>=-128 && v<=127) {
						  emitb(0x83); modrm(3, $1, $2);
						  emits($4.sym,$4.ofs,REL_abs8);
					      } else {
						  emitb(0x81); modrm(3, $1, $2);
						  emits($4.sym,$4.ofs,REL_abs32);
					      }
					  } else {
					      modrm (0,$1,5);
					      emits($4.sym,$4.ofs,REL_abs32);
					  }
					}
	| ARITH2 REG32 ',' REG32	{ emitb(0x66); emitb($1*8+1); modrm(3, $4, $2); }
	| ARITH2 regmem ',' REG32	{ emitb(0x66); emitb($1*8+1); reg($4); }
	| ARITH2 REG32 ',' regmem	{ emitb(0x66); emitb($1*8+3); reg($2); }

	| ARPL REG16 ',' REG16		{ emitb(0x63); modrm(3,$4,$2); }
	| ARPL regmem ',' REG16		{ emitb(0x63); reg($4); }

	| ASCADJ			{ emitb($1); emitb(0x0a); }
	| ASCADJ const			{ emitb($1); emitb($2); }

	| ALIGN const			{ do_align($2,0x90); }
	| ALIGN const ',' const		{ do_align($2,$4); }

	| BOUND REG16 ',' regmem	{ emitb(0x62); reg($2); }
	| BOUND REG32 ',' regmem	{ emitb(0x66); emitb(0x62); reg($2); }

	| BITTEST REG16 ',' REG16	{ emitb(0x0f); emitb($1*8+0x83); modrm(3, $4, $2); }
	| BITTEST regmem ',' REG16	{ emitb(0x0f); emitb($1*8+0x83); reg($4); }
	| BITTEST REG32 ',' REG32	{ emitb(0x66); emitb(0x0f); emitb($1*8+0x83); modrm(3, $4, $2); }
	| BITTEST regmem ',' REG32	{ emitb(0x66); emitb(0x0f); emitb($1*8+0x83); reg($4); }
	| BITTEST REG16 ',' const	{ emitb(0x0f); emitb(0xba); modrm(3, $1, $2); emitb($4); }
	| BITTEST regmem ',' const	{ emitb(0x0f); emitb(0xba); reg($1); emitb($4); }
	| BITTEST REG32 ',' const	{ emitb(0x66); emitb(0x0f); emitb(0xba); modrm(3, $1, $2); emitb($4); }

	| BSF REG16 ',' REG16		{ emitb(0x0f); emitb(0xbc); modrm(3, $4, $2); }
	| BSF REG16 ',' regmem		{ emitb(0x0f); emitb(0xbc); reg($2); }
	| BSF REG32 ',' REG32		{ emitb(0x66); emitb(0x0f); emitb(0xbc); modrm(3, $4, $2); }
	| BSF REG32 ',' regmem		{ emitb(0x66); emitb(0x0f); emitb(0xbc); reg($2); }

	| BSR REG16 ',' REG16		{ emitb(0x0f); emitb(0xbd); modrm(3, $4, $2); }
	| BSR REG16 ',' regmem		{ emitb(0x0f); emitb(0xbd); reg($2); }
	| BSR REG32 ',' REG32		{ emitb(0x66); emitb(0x0f); emitb(0xbd); modrm(3, $4, $2); }
	| BSR REG32 ',' regmem		{ emitb(0x66); emitb(0x0f); emitb(0xbd); reg($2); }

	| CALL ID			{ emitb(0xe8); emits($2,0,REL_16); $2->type |= SYM_code; }
	| CALL REG16			{ emitb(0xff); modrm(3,2,$2); }
	| CALL regmem			{ emitb(0xff); reg(2); }
	| CALLF regmem			{ emitb(0xff); reg(3); }
	| CALLF const ':' constID	{ emitb(0x9a); emits($4.sym,$4.ofs,REL_abs); emitw($2); }
	| CALLFD const ':' constID	{ emitb(0x66); emitb(0x9a); emits($4.sym,$4.ofs,REL_abs32); emitw($2); }

	| COPYRIGHT STRING		{ strbuf[strbuflen] = 0; add_copyright(strbuf); }
	| RCS_ID			{ strbuf[strbuflen] = 0; add_rcs_ident(strbuf); }

	| DB dblist
	| DW dwlist
	| DD ddlist

	| DEC REG8			{ emitb(0xfe); modrm(3, 1, $2); }
	| DECB regmem			{ emitb(0xfe); reg(1); }
	| DEC REG16			{ emitb(0x48 + $2); }
	| DEC REG32			{ emitb(0x66); emitb(0x48 + $2); }
	| DECW regmem			{ emitb(0xff); reg(1); }
	| DECD regmem			{ emitb(0x66); emitb(0xff); reg(1); }

	| ENTER const ',' const		{ emitb(0xc8); emitw($2); emitb($4); }

	| IN REG8 ',' const		{ emitb(0xe4); emitb($4); }
	| IN REG16 ',' const		{ emitb(0xe5); emitb($4); }
	| IN REG32 ',' const		{ emitb(0x66); emitb(0xe5); emitb($4);}
	| IN REG8 ',' REG16		{ emitb(0xec); }
	| IN REG16 ',' REG16		{ emitb(0xed); }
	| IN REG32 ',' REG16		{ emitb(0x66); emitb(0xed); }

	| INC REG8			{ emitb(0xfe); modrm(3, 0, $2); }
	| INCB regmem			{ emitb(0xfe); reg(0); }
	| INC REG16			{ emitb(0x40 + $2); }
	| INC REG32			{ emitb(0x66); emitb(0x40 + $2); }
	| INCW regmem			{ emitb(0xff); reg(0); }
	| INCD regmem			{ emitb(0x66); emitb(0xff); reg(0); }

	| IMUL REG8			{ emitb(0xf6); modrm(3, 5, $2); }
	| IMULB regmem			{ emitb(0xf6); reg(5); }
	| IMUL REG16			{ emitb(0xf7); modrm(3, 5, $2); }
	| IMULW regmem			{ emitb(0xf7); reg(5); }
	| IMUL REG32			{ emitb(0x66); emitb(0xf7); modrm(3, 5, $2); }
	| IMULD regmem			{ emitb(0x66); emitb(0xf7); reg(5); }
	| IMUL REG16 ',' REG16		{ emitb(0x0f); emitb(0xaf); modrm(3, $2, $4);}
	| IMUL REG32 ',' REG32		{ emitb(0x66); emitb(0x0f); emitb(0xaf); modrm(3, $2, $4);}
	| IMUL REG16 ',' regmem		{ emitb(0x0f); emitb(0xaf); reg($2); }
	| IMUL REG32 ',' regmem		{ emitb(0x66); emitb(0x0f); emitb(0xaf); reg($2); }
	| IMUL REG16 ',' REG16 ',' const { if ($6>=-128 && $6<=127)
					      emitb(0x6b);
					  else
					      emitb(0x69);
					  modrm(3, $2, $4);
					  if ($6>=-128 && $6<=127)
					      emitb($6);
					  else
					      emitw($6);
					}
	| IMUL REG32 ',' REG32 ',' const { emitb(0x66);
					  if ($6>=-128 && $6<=127)
					      emitb(0x6b);
					  else
					      emitb(0x69);
					  modrm(3, $2, $4);
					  if ($6>=-128 && $6<=127)
					      emitb($6&0xff);
					  else
					      emitd($6);
					}

	| IMUL REG16 ',' regmem ',' const { if ($6>=-128 && $6<=127)
					      emitb(0x6b);
					  else
					      emitb(0x69);
					  reg($2);
					  if ($6>=-128 && $6<=127)
					      emitb($6);
					  else
					      emitw($6);
					}
	| IMUL REG32 ',' regmem ',' const { emitb(0x66);
					  if ($6>=-128 && $6<=127)
					      emitb(0x6b);
					  else
					      emitb(0x69);
					  reg($2);
					  if ($6>=-128 && $6<=127)
					      emitb($6&0xff);
					  else
					      emitd($6);
					}

	| GROUP3 REG8			{ emitb(0xf6); modrm(3, $1, $2); }
	| GROUP3B regmem		{ emitb(0xf6); reg($1); }
	| GROUP3 REG16			{ emitb(0xf7); modrm(3, $1, $2); }
	| GROUP3W regmem		{ emitb(0xf7); reg($1); }
	| GROUP3 REG32			{ emitb(0x66); emitb(0xf7); modrm(3, $1, $2); }
	| GROUP3D regmem		{ emitb(0x66); emitb(0xf7); reg($1); }

	| GROUP6 regmem			{ emitb(0x0f); emitb(0x00); reg($1); }
	| GROUP6 REG16			{ emitb(0x0f); emitb(0x00); modrm(3, $1, $2); }
	| GROUP7 regmem			{ emitb(0x0f); emitb(0x01); reg($1); }
	| GROUP7 REG16			{ emitb(0x0f); emitb(0x01); modrm(3, $1, $2); }

	| INT const			{ if ($2 == 3) emitb(0xcc); else emitb(0xcd), emitb($2); }

	| JCC ID       			{ emitb(0x70+$1); emits($2,0,REL_8); $2->type |= SYM_code; }
	| JCCL ID			{ emitb(0x0f); emitb(0x80+$1); emits($2,0,REL_16); $2->type |= SYM_code; }

	| JCXZ ID			{ if ($1) emitb(0x66); emitb(0xe3); emits($2,0,REL_8); $2->type |= SYM_code; }

	| JMPW ID			{ emitb(0xe9); emits($2,0,REL_16); $2->type |= SYM_code; }
	| JMPB ID			{ emitb(0xeb); emits($2,0,REL_8); $2->type |= SYM_code; }
	| JMPB REG16			{ emitb(0xff); modrm(3,4,$2); }
	| JMPB regmem			{ emitb(0xff); reg(4); }
	| JMPF regmem			{ emitb(0xff); reg(5); }
	| JMPF const ':' constID	{ emitb(0xea); emits($4.sym,$4.ofs,REL_abs); emitw($2); }
	| JMPFD const ':' constID	{ emitb(0x66); emitb(0xea); emits($4.sym,$4.ofs,REL_abs32); emitw($2); }

	| LAR REG16 ',' REG16		{ emitb(0x0f); emitb(0x02); modrm(3, $4, $2); }
	| LAR REG16 ',' regmem		{ emitb(0x0f); emitb(0x02); reg($2); }

	| LEA REG16 ',' regmem		{ emitb(0x8d); reg($2); }
	| LEA REG32 ',' regmem		{ emitb(0x66); emitb(0x8d); reg($2); }

	| LINKCOFF STRING		{ strbuf[strbuflen]=0; do_linkcoff(strbuf); }
	| LOOP ID			{ emitb($1); emits($2,0,REL_8); }

	| LSL REG16 ',' REG16		{ emitb(0x0f); emitb(0x03); modrm(3, $4, $2); }
	| LSL REG16 ',' regmem		{ emitb(0x0f); emitb(0x03); reg($2); }

	| LXS REG16 ',' regmem		{ if ($1>>8) emitb($1>>8); emitb($1 & 0xff); reg($2); }
	| LXS REG32 ',' regmem		{ emitb(0x66); if ($1>>8) emitb($1>>8); emitb($1 & 0xff); reg($2); }

	| MOVB regmem ',' const		{ emitb(0xc6), reg(0); emitb($4); }
	| MOV REG8 ',' const		{ emitb(0xb0+$2); emitb($4); }
	| MOV REG8 ',' REG8		{ emitb(0x88), modrm(3, $4, $2); }
	| MOV regmem ',' REG8		{ if ($4==0 && _modrm.regs==0)
					      movacc=0xa2;
					  else
					      emitb(0x88); 
					  reg($4); 
					}
	| MOV REG8 ',' regmem		{ if ($2==0 && _modrm.regs==0)
					      movacc=0xa0;
					  else
					      emitb(0x8a);
					  reg($2);
					}
	| MOVW regmem ',' constID	{ emitb(0xc7); reg(0); emits($4.sym,$4.ofs,REL_abs); }
	| MOV REG16 ',' constID		{ emitb(0xb8+$2); emits($4.sym,$4.ofs,REL_abs); }
	| MOV REG16 ',' REG16		{ emitb(0x89); modrm(3, $4, $2); }
	| MOV regmem ',' REG16		{ if ($4==0 && _modrm.regs==0)
					      movacc=0xa3;
					  else
					      emitb(0x89);
					  reg($4); 
					}
	| MOV REG16 ','	regmem		{ if ($2==0 && _modrm.regs==0)
					      movacc=0xa1;
					  else
					      emitb(0x8b);
					  reg($2);
					}
	| MOVD regmem ',' constID	{ emitb(0x66); emitb(0xc7); reg(0); emits($4.sym,$4.ofs,REL_abs32); }
	| MOV REG32 ',' constID		{ emitb(0x66); emitb(0xb8+$2); emits($4.sym,$4.ofs,REL_abs32); }
	| MOV REG32 ',' REG32		{ emitb(0x66); emitb(0x89); modrm(3, $4, $2); }
	| MOV regmem ',' REG32		{ emitb(0x66);
					  if ($4==0 && _modrm.regs==0)
					      movacc=0xa3;
					  else
					      emitb(0x89);
					  reg($4);
					}
	| MOV REG32 ','	regmem		{ emitb(0x66);
					  if ($2==0 && _modrm.regs==0)
					      movacc=0xa1;
					  else
					      emitb(0x8b);
					  reg($2);
					}
	| MOV regmem ',' SREG		{ emitb(0x8c); reg($4); }
	| MOV REG16 ',' SREG		{ emitb(0x8c); modrm(3, $4, $2); }
	| MOV SREG ',' regmem		{ emitb(0x8e); reg($2); }
	| MOV SREG ',' REG16		{ emitb(0x8e); modrm(3, $2, $4); }

	| MOV CRREG ',' REG32		{ emitb(0x0f); emitb(0x22); modrm(3, $2, $4); }
	| MOV DRREG ',' REG32		{ emitb(0x0f); emitb(0x23); modrm(3, $2, $4); }
	| MOV TRREG ',' REG32		{ emitb(0x0f); emitb(0x26); modrm(3, $2, $4); }
	| MOV REG32 ',' CRREG		{ emitb(0x0f); emitb(0x20); modrm(3, $4, $2); }
	| MOV REG32 ',' DRREG		{ emitb(0x0f); emitb(0x21); modrm(3, $4, $2); }
	| MOV REG32 ',' TRREG		{ emitb(0x0f); emitb(0x24); modrm(3, $4, $2); }

	| MOVSZX REG16 ',' REG8		{ emitb(0x0f); emitb($1); modrm(3, $2, $4); }
	| MOVSZX REG32 ',' REG8		{ emitb(0x66); emitb(0x0f); emitb($1); modrm(3, $2, $4); }
	| MOVSZX REG32 ',' REG16	{ emitb(0x66); emitb(0x0f); emitb($1+1); modrm(3, $2, $4); }

	| MOVSZXB REG16 ',' regmem	{ emitb(0x0f); emitb($1); reg($2); }
	| MOVSZXB REG32 ',' regmem	{ emitb(0x66); emitb(0x0f); emitb($1); reg($2); }
	| MOVSZXW REG32 ',' regmem	{ emitb(0x66); emitb(0x0f); emitb($1+1); reg($2); }

	| ORG const			{ if (pc > $2) djerror ("Backwards org directive"); else while (pc < $2) emitb(0x90); }
	| ORG const ',' const		{ if (pc > $2) djerror ("Backwards org directive"); else while (pc < $2) emitb($4); }

	| OUT const ',' REG8		{ emitb(0xe6); emitb($2); }
	| OUT const ',' REG16		{ emitb(0xe7); emitb($2); }
	| OUT const ',' REG32		{ emitb(0x66); emitb(0xe7); emitb($2);}
	| OUT REG16 ',' REG8		{ emitb(0xee); }
	| OUT REG16 ',' REG16		{ emitb(0xef); }
	| OUT REG16 ',' REG32		{ emitb(0x66); emitb(0xef); }

	| POP REG16			{ emitb(0x58 + $2); }
	| POP REG32			{ emitb(0x66); emitb(0x58 + $2); }
	| POP SREG			{ do_sreg_pop($2); }
	| POPW regmem			{ emitb(0x8f); reg(0); }
	| POPD regmem			{ emitb(0x66); emitb(0x8f); reg(0); }
	| PUSH REG16			{ emitb(0x50 + $2); }
	| PUSH REG32			{ emitb(0x66); emitb(0x50 + $2); }
	| PUSH SREG			{ do_sreg_push($2); }
	| PUSHW regmem			{ emitb(0xff); reg(6); }
	| PUSHD regmem			{ emitb(0x66); emitb(0xff); reg(6); }
	| PUSHB const			{ emitb(0x6a); emitb($2); }
	| PUSHW constID			{ emitb(0x68); emits($2.sym,$2.ofs,REL_abs); }
	| PUSHD constID			{ emitb(0x66); emitb(0x68); emits($2.sym,$2.ofs,REL_abs32); }

	| RET				{ emitb(0xc3); }
	| RET const			{ emitb(0xc2); emitw($2); }
	| RETF				{ emitb(0xcb); }
	| RETF const			{ emitb(0xca); emitw($2); }
	| RETD				{ emitb(0x66); emitb(0xc3); }
	| RETD const			{ emitb(0x66); emitb(0xc2); emitd($2); }
	| RETFD				{ emitb(0x66); emitb(0xcb); }
	| RETFD const			{ emitb(0x66); emitb(0xca); emitd($2); }

	| SETCC REG8			{ emitb(0x0f); emitb(0x90+$1); modrm(3, 0, $2); }
	| SETCC regmem			{ emitb(0x0f); emitb(0x90+$1); reg(0); }

	/* basic shift of register or memory (byte/word/double) operand */
	| SHIFT REG8 ',' const		{ emitb($4 == 1 ? 0xd0 : 0xc0); modrm(3, $1, $2); if ($4 != 1) emitb($4); }
	| SHIFT REG8 ',' REG8		{ if ($4 != 1) djerror ("Non-constant shift count must be `cl'"); emitb(0xd2); modrm(3, $1, $2); }
	| SHIFTB regmem ',' const	{ emitb($4 == 1 ? 0xd0 : 0xc0); reg($1); if ($4 != 1) emitb($4); }
	| SHIFTB regmem ',' REG8	{ if ($4 != 1) djerror ("Non-constant shift count must be `cl'"); emitb(0xd2); reg($1); }
	| SHIFT REG16 ',' const       	{ emitb($4 == 1 ? 0xd1 : 0xc1); modrm(3, $1, $2); if ($4 != 1) emitb($4); }
	| SHIFT REG16 ',' REG8		{ if ($4 != 1) djerror ("Non-constant shift count must be `cl'"); emitb(0xd3); modrm(3, $1, $2); }
	| SHIFTW regmem ',' const	{ emitb($4 == 1 ? 0xd1 : 0xc1); reg($1); if ($4 != 1) emitb($4); }
	| SHIFTW regmem ',' REG8	{ if ($4 != 1) djerror ("Non-constant shift count must be `cl'"); emitb(0xd3); reg($1); }
	| SHIFT REG32 ',' const       	{ emitb(0x66); emitb($4 == 1 ? 0xd1 : 0xc1); modrm(3, $1, $2); if ($4 != 1) emitb($4); }
	| SHIFT REG32 ',' REG8		{ if ($4 != 1) djerror ("Non-constant shift count must be `cl'"); emitb(0x66); emitb(0xd3); modrm(3, $1, $2); }
	| SHIFTD regmem ',' const	{ emitb(0x66); emitb($4 == 1 ? 0xd1 : 0xc1); reg($1); if ($4 != 1) emitb($4); }
	| SHIFTD regmem ',' REG8	{ if ($4 != 1) djerror ("Non-constant shift count must be `cl'"); emitb(0x66); emitb(0xd3); reg($1); }

	/* Trap any use of `sh[lr]d' to denote a double-precision shift.
	This trap is not strictly necessary, because writing `sh[lr]d'
	with three operands would generate a parse error anyway.  However,
	there _was_ a time when djasm did use `sh[lr]d' as the mnemonics
	for the double-precision shifts.  This usage was later removed
	(it interfered with subsequent implementation of the basic shift
	instructions with memory operands).  (jtw) */

	| SHIFTD REG16 ',' REG16 ',' const	{ shxd_error($1); }
	| SHIFTD REG16 ',' REG16 ',' REG8	{ shxd_error($1); }
	| SHIFTD regmem ',' REG16 ',' const	{ shxd_error($1); }
	| SHIFTD regmem ',' REG16 ',' REG8	{ shxd_error($1); }
	| SHIFTD REG32 ',' REG32 ',' const	{ shxd_error($1); }
	| SHIFTD REG32 ',' REG32 ',' REG8	{ shxd_error($1); }
	| SHIFTD regmem ',' REG32 ',' const	{ shxd_error($1); }
	| SHIFTD regmem ',' REG32 ',' REG8	{ shxd_error($1); }

	/* The double-precision shift instructions do *not* require
	a memory operand-size suffix.  The size of the memory operand
	must agree with the size of the register, hence the allowable
	combinations of operands are completely unambiguous.  (jtw) */

	/* 16-bit double-precision shift */
	| DPSHIFT REG16 ',' REG16 ',' const	{ emitb(0x0f); emitb($1); modrm(3, $4, $2); emitb($6); }
	| DPSHIFT REG16 ',' REG16 ',' REG8	{ if ($6 != 1) djerror ("Non-constant shift count must be `cl'"); emitb(0x0f); emitb($1+1); modrm(3, $4, $2); }
	| DPSHIFT regmem ',' REG16 ',' const	{ emitb(0x0f); emitb($1); reg($4); emitb($6); }
	| DPSHIFT regmem ',' REG16 ',' REG8	{ if ($6 != 1) djerror ("Non-constant shift count must be `cl'"); emitb(0x0f); emitb($1+1); reg($4); }

	/* 32-bit double-precision shift */
	| DPSHIFT REG32 ',' REG32 ',' const	{ emitb(0x66); emitb(0x0f); emitb($1); modrm(3, $4, $2); emitb($6); }
	| DPSHIFT REG32 ',' REG32 ',' REG8	{ if ($6 != 1) djerror ("Non-constant shift count must be `cl'"); emitb(0x66); emitb(0x0f); emitb($1+1); modrm(3, $4, $2); }
	| DPSHIFT regmem ',' REG32 ',' const	{ emitb(0x66); emitb(0x0f); emitb($1); reg($4); emitb($6); }
	| DPSHIFT regmem ',' REG32 ',' REG8	{ if ($6 != 1) djerror ("Non-constant shift count must be `cl'"); emitb(0x66); emitb(0x0f); emitb($1+1); reg($4); }

	| STACK				{ stack_ptr = pc; }
	| START				{ start_ptr = pc; main_obj=1; }

	| TESTB regmem ',' const	{ emitb(0xf6), reg(0); emitb($4); }
	| TEST REG8 ',' const		{ emitb(0xf6), modrm(3, 0, $2); emitb($4); }
	| TEST REG8 ',' REG8		{ emitb(0x84), modrm(3, $4, $2); }
	| TEST regmem ',' REG8		{ emitb(0x84), reg($4); }
	| TEST REG8 ',' regmem		{ emitb(0x84), reg($2); }

	| TESTW regmem ',' constID	{ emitb(0xf7); reg(0); emits($4.sym,$4.ofs,REL_abs); }
	| TEST REG16 ',' constID	{ emitb(0xf7); modrm(3, 0, $2); emits($4.sym,$4.ofs,REL_abs); }
	| TEST REG16 ',' REG16		{ emitb(0x85); modrm(3, $4, $2); }
	| TEST regmem ',' REG16		{ emitb(0x85); reg($4); }
	| TEST REG16 ',' regmem		{ emitb(0x85); reg($2); }

	| TESTD regmem ',' constID	{ emitb(0x66); emitb(0xf7); reg(0); emits($4.sym,$4.ofs,REL_abs32); }
	| TEST REG32 ',' constID	{ emitb(0x66); emitb(0xf7); modrm(3, 0, $2); emits($4.sym,$4.ofs,REL_abs32); }
	| TEST REG32 ',' REG32		{ emitb(0x66); emitb(0x85); modrm(3, $4, $2); }
	| TEST regmem ',' REG32		{ emitb(0x66); emitb(0x85); reg($4); }
	| TEST REG32 ',' regmem		{ emitb(0x66); emitb(0x85); reg($2); }

	| TYPE STRING			{ strbuf[strbuflen] = 0; set_image_type(strbuf); }
	| TYPE NUMBER			{ if ($2 == 'h') set_out_type("h"); }

	| XCHG REG8 ',' REG8		{ emitb(0x86); modrm(3, $2, $4); }
	| XCHG REG8 ',' regmem		{ emitb(0x86); reg($2); }
	| XCHG regmem ',' REG8		{ emitb(0x86); reg($4); }
	| XCHG REG16 ',' REG16		{ if (($2==0) ^	($4==0))
					      emitb(0x90+$2+$4);
					  else
					      {emitb(0x87); modrm(3, $2, $4); }
					}      
	| XCHG REG16 ',' regmem		{ emitb(0x87); reg($2); }
	| XCHG regmem ',' REG16		{ emitb(0x87); reg($4); }
	| XCHG REG32 ',' REG32		{ emitb(0x66);
					  if (($2==0) ^	($4==0))
					      emitb(0x90+$2+$4);
					  else
					      {emitb(0x87); modrm(3, $2, $4); }
					}
	| XCHG REG32 ',' regmem		{ emitb(0x66); emitb(0x87); reg($2); }
	| XCHG regmem ',' REG32		{ emitb(0x66); emitb(0x87); reg($4); }
	;

struct_lines
	:
	| struct_lines struct_line '\n'	{ lineno++; }
	;

struct_line
	:
	| ID ':'			{ add_struct_element($1); }
	| ID STRUCT ID			{ build_struct($1,$2,$3); }
	| STRUCT ID			{ build_struct(0,$1,$2); }
	| struct_db
	| ID				{ add_struct_element($1); }
	  struct_db
	;

enum_lines
	:
	| enum_lines enum_line '\n' { lineno++; }
	;

enum_line
	:
	| ID				{ add_enum_element($1); }
	| ID '=' const			{ struct_pc = $3; add_enum_element($1); }
	;

struct_db
	: DB				{ if (struct_tp=='s') {
					      struct_pc++;
					  } else {
					      struct_pc=MAX(struct_pc,1);
					  }
					}
	| DB const DUP			{ if (struct_tp=='s') {
					      struct_pc+=$2;
					  } else {
					      struct_pc=MAX(struct_pc,$2);
					  }
					}
	| DW				{ if (struct_tp=='s') {
					      struct_pc+=2;
					  } else {
					      struct_pc=MAX(struct_pc,2);
					  }
					}
	| DW const DUP			{ if (struct_tp=='s') {
					      struct_pc+=2*$2;
					  } else {
					      struct_pc=MAX(struct_pc,2*$2);
					  }
					}
	| DD				{ if (struct_tp=='s') {
					      struct_pc+=4;
					  } else {
					      struct_pc=MAX(struct_pc,4);
					  }
					}
	| DD const DUP			{ if (struct_tp=='s') {
					      struct_pc+=4*$2;
					  } else {
					      struct_pc=MAX(struct_pc,4*$2);
					  }
					}
	;
 

dbitem
	: const				{ emitb($1); }
	| STRING			{ emit(strbuf, strbuflen); }
	| const DUP const		{ for (i=0; i<$1; i++) emitb($3); }
	;

dblist
	: dbitem
	| dblist ',' dbitem
	;

dwitem
	: const				{ emitw($1); }
	| UID offset			{ emits($1,$2,REL_abs); }
	| const DUP const		{ for (i=0; i<$1; i++) emitw($3); }
	;

dwlist
	: dwitem
	| dwlist ',' dwitem
	;

dditem
	: const				{ emitd($1); }
	| UID offset			{ emits($1,$2,REL_abs32); }
	| const DUP const		{ for (i=0; i<$1; i++) emitd($3); }
	;

ddlist
	: dditem
	| ddlist ',' dditem
	;

regmem
	: regmemitem '[' regmemexpr ']'
	| '[' regmemexpr ']'
	| SREG ':' '[' regmemexpr ']'	{ emitb(sreg_overrides[$1]); }
	;

regmemexpr
	: regmemitem
	| regmemexpr '+' regmemexpr
 	| regmemexpr '-' const		{ _modrm.offset -= $3; }
	;

regmemitem
	: SREG ':' regmemitem		{ emitb(sreg_overrides[$1]); }
	| REG16				{ if (_modrm.addr32) {
					      _modrm.nsyms = _modrm.addr32 = _modrm.addr16 = _modrm.offset = _modrm.regs = 0;
					      djerror("Cannot mix 16 and 32 bit addressing");
					  } else {
					      _modrm.regs |= (1<<$1);
					      _modrm.addr16=1;
					  }
					}
	| REG32				{ addr32((1<<$1)|0x100); }
	| scaledindex			{ addr32($1); }
	| UID				{ _modrm.syms[_modrm.nsyms++] = $1; }
	| const				{ _modrm.offset += $1; }
	;

scaledindex
	: REG32 '*' const		{ if ($3==1 || $3==2 || $3==4 || $3==8)
					      $$ = (1<<($1)) | ($3<<8);
					  else {
					      _modrm.nsyms = _modrm.addr32 = _modrm.addr16 = _modrm.offset = _modrm.regs = 0;
					      djerror("Scale must be 1,2,4 or 8");
					  }
					}
	| const '*' REG32		{ if ($1==1 || $1==2 || $1==4 || $1==8)
					      $$ = (1<<($3)) | ($1<<8);
					  else {
					      _modrm.nsyms = _modrm.addr32 = _modrm.addr16 = _modrm.offset = _modrm.regs = 0;
					      djerror("Scale must be 1,2,4 or 8");
					  }
					}
	| REG32 OP_SHL const		{ if ($3>=0 && $3<=3)
					      $$ = (1<<($1)) | (0x100<<$3);
					  else {
					      _modrm.nsyms = _modrm.addr32 = _modrm.addr16 = _modrm.offset = _modrm.regs = 0;
					      djerror("Shift must be 0,1,2 or 3");
					  }
					}
	;

const
	: NUMBER			{ $$ = $1; }
	| KID				{ $$ = $1->value; }
	| PC				{ $$ = pc_symbol.value; }
	| const OP_OR const		{ $$ = $1 || $3; }
	| const '|' const		{ $$ = $1 | $3; }
	| const '^' const		{ $$ = $1 ^ $3; }
	| const OP_AND const		{ $$ = $1 && $3; }
	| const '&' const		{ $$ = $1 & $3; }
	| const '=' const		{ $$ = $1 == $3; }
	| const '>' const		{ $$ = $1 > $3; }
	| const '<' const		{ $$ = $1 < $3; }
	| const OP_GE const		{ $$ = $1 >= $3; }
	| const OP_LE const		{ $$ = $1 <= $3; }
	| const OP_NE const		{ $$ = $1 != $3; }
	| const OP_SHL const		{ $$ = $1 << $3; }
	| const OP_SHR const		{ $$ = $1 >> $3; }
	| const '+' const		{ $$ = $1 + $3; }
	| const '-' const		{ $$ = $1 - $3; }
	| const '*' const		{ $$ = $1 * $3; }
	| const '/' const		{ $$ = $1 / $3; }
	| const '%' const		{ $$ = $1 % $3; }
	| '-' const %prec OP_NEG	{ $$ = -$2; }
	| '!' const %prec OP_NOT	{ $$ = !$2; }
	| '~' const %prec OP_LNOT	{ $$ = ~$2; }
	| '(' const ')'			{ $$ = $2; }
	;

ID
	: KID				{ $$ = $1; }
	| UID				{ $$ = $1; }
	;

constID
	: UID offset			{ $$.sym = $1; $$.ofs = $2; }
	| const				{ $$.sym = zerosym; $$.ofs = $1; }
	;

offset
	: '+' const			{ $$ = $2; }
	| '-' const			{ $$ = -$2; }
	| 				{ $$ = 0; }
	;

%% /***********************************************************************/

typedef struct FileStack {
  struct FileStack *prev;
  FILE *f;
  int line;
  char *name;
} FileStack;

FileStack *file_stack = 0;

FILE *infile;
FILE *outfile;

int scmp_a(void const *a, void const *b)
{
  return strcmp((*(Symbol **)a)->name, (*(Symbol **)b)->name);
}

int scmp_n(void const *a, void const *b)
{
  return (*(Symbol **)a)->value - (*(Symbol **)b)->value;
}

static int
opcode_compare (const void *e1, const void *e2)
{
  return strcmp (((struct opcode *)e1)->name, ((struct opcode *)e2)->name);
}

int main(int argc, char **argv)
{
  Symbol *s;
  Patch *p;
  unsigned char exe[EXE_HEADER_SIZE+4];
  int symcount = 0;
  int min_uninit;
  time_t now;
  char *outfilename, *leader;
  char *current_map_file;

  /* Sort the opcodes now so that we can use `bsearch' later.  */
  qsort (opcodes,
	 sizeof (opcodes) / sizeof (opcodes[0]),
	 sizeof (opcodes[0]),
	 opcode_compare);
  zerosym = set_symbol (get_symbol ("__zero__", 1), 0);

  if (argc < 2)
  {
    fprintf(stderr,"usage: djasm infile [outfile] [mapfile]\n");
    exit(1);
  }
  inname = argv[1];
  infile = fopen(argv[1], "r");
  if (infile == 0)
  {
    fprintf(stderr, "Error: cannot open file %s for reading\n", argv[1]);
    perror("The error was");
    exit(1);
  }
  yyparse();
  fclose(infile);
  if (bsspc == -1)
  {
    bsspc = pc;
    generated_bytes = last_align_end==pc ? last_align_begin : pc;
  }

  sortsyms(scmp_a);

  for (s=symtab; s; s=s->next)
  {
    if (!istemp(s->name, 0))
      symcount++;
    if (!s->defined && s->patches)
    {
      for (p=s->patches; p; p=p->next)
	fprintf(stderr,"%s:%d: undefined symbol `%s'\n", p->filename, p->lineno, s->name);
      undefs++;
    }
  }
  if (undefs)
    return 1;
  if (total_errors)
  {
    fprintf(stderr, "%s: %d errors\n", inname, total_errors);
    return 1;
  }

  printf("%#x bytes generated, %#x bytes in file, %#x bytes total, %d symbols\n",
    generated_bytes, bsspc, pc, symcount);

  min_uninit = (pc-bsspc+15)/16;

  memset(exe, 0, EXE_HEADER_SIZE+4);
  exe[0] = 0x4d;		/* MAGIC */
  exe[1] = 0x5a;
  exe[2] = bsspc;		/* bytes in last page */
  exe[3] = (bsspc>>8)&1;
  exe[4] = (bsspc+1023)>>9;	/* number of sectors */
  exe[5] = (bsspc+1023)>>17;
  exe[6] = 0;			/* relocation entries */
  exe[7] = 0;
  exe[8] = EXE_HEADER_BLOCKS;	/* blocks in header */
  exe[9] = 0;
  exe[10] = min_uninit;		/* min uninitialized paragraphs */
  exe[11] = (min_uninit>>8);
  exe[12] = 0xff;		/* max uninitialized paragraphs */
  exe[13] = 0xff;
  exe[14] = 0;			/* relative SS */
  exe[15] = 0;
  exe[16] = stack_ptr;		/* SP */
  exe[17] = stack_ptr>>8;
  exe[18] = 0;			/* checksum */
  exe[19] = 0;
  exe[20] = start_ptr;		/* IP */
  exe[21] = start_ptr >> 8;
  exe[22] = 0;			/* relative CS */
  exe[23] = 0;

  /* These must be zero, otherwise they are interpreted as an offset to 
     a "new executable" header. */
  exe[60] = 0;
  exe[61] = 0;
  exe[62] = 0;
  exe[63] = 0;
#define INFO_TEXT_START (64)

  time(&now);

  sprintf(exe+INFO_TEXT_START, "\r\n%s generated from %s by djasm, on %.24s\r\n", argv[2], argv[1], ctime(&now));
  if (copyright)
    strncat(exe+INFO_TEXT_START, copyright, (512-3-INFO_TEXT_START)-strlen(exe+INFO_TEXT_START)); /* -3 for the following line: */
  strcat(exe+INFO_TEXT_START, "\r\n\032");

  if (argv[2] == 0)
  {
    char *dot=0, *sl=0, *cp;
    outfilename = (char *)malloc(strlen(argv[1])+5);
    strcpy(outfilename, argv[1]);
    for (cp=outfilename; *cp; cp++)
    {
      if (*cp == ':' || *cp == '\\' || *cp == '/')
      {
        sl = cp+1;
        dot = 0;
      }
      if (*cp == '.')
        dot = cp;
    }
    if (!dot)
    {
      dot = cp;
      *dot = '.';
    }
    strcpy(dot+1, ext_types[out_type]);
  }
  else
  {
    char *dot=0, *sl=0, *cp;
    outfilename = argv[2];
    for (cp=outfilename; *cp; cp++)
    {
      if (*cp == ':' || *cp == '\\' || *cp == '/')
      {
        sl = cp+1;
        dot = 0;
      }
      if (*cp == '.')
        dot = cp;
    }
    if (!dot)
    {
      sl = (char *)malloc(strlen(outfilename)+5);
      strcpy(sl, outfilename);
      outfilename = sl;
      dot = outfilename + strlen(outfilename);
      *dot = '.';
      strcpy(dot+1, ext_types[out_type]);
    }
    else
      set_out_type(dot+1);
  }

  switch (out_type)
  {
    case OUT_exe:
    case OUT_com:
    case OUT_bin:
    case OUT_sys:
    case OUT_obj:
      outfile = fopen(outfilename, "wb");
      break;
    case OUT_h:
    case OUT_inc:
    case OUT_s:
      outfile = fopen(outfilename, "w");
      break;
  }
  if (outfile == 0)
  {
    fprintf(stderr, "Error: cannot open file %s for writing\n", outfilename);
    perror("The error was");
    exit(1);
  }

  switch (out_type)
  {
    case OUT_exe:
      fwrite(exe, EXE_HEADER_SIZE, 1, outfile);
      fwrite(outbin, bsspc, 1, outfile);
      break;

    case OUT_com:
      fwrite(outbin+256, bsspc-256, 1, outfile);
      break;

    case OUT_bin:
    case OUT_sys:
      fwrite(outbin, bsspc, 1, outfile);
      break;

    case OUT_h:
      if (image_type == OUT_exe)
        for (i=0; i<EXE_HEADER_SIZE; i++)
        {
          fprintf(outfile, "0x%02x,", exe[i]);
          if ((i&15) == 15)
            fputc('\n', outfile);
        }
      for (i=((image_type==OUT_com)?0x100:0); i<bsspc; i++)
      {
        fprintf(outfile, "0x%02x", outbin[i]);
        if (i<bsspc-1)
          fputc(',', outfile);
        if ((i&15) == 15)
          fputc('\n', outfile);
      }
      if (i&15)
        fputc('\n', outfile);
      break;

    case OUT_inc:
    case OUT_s:
      if (out_type == OUT_inc)
        leader = INC_LEADER;
      else
        leader = S_LEADER;
      fputs(leader, outfile);
      if (image_type == OUT_exe)
        for (i=0; i<EXE_HEADER_SIZE; i++)
        {
          fprintf(outfile, "0x%02x", exe[i]);
          if ((i&15) == 15)
          {
            fputc('\n', outfile);
            fputs(leader, outfile);
          }
          else
            fputc(',', outfile);
        }
      for (i=((image_type==OUT_com)?0x100:0); i<bsspc; i++)
      {
        fprintf(outfile, "0x%02x", outbin[i]);
        if ((i&15) == 15)
        {
          fputc('\n', outfile);
          if (i<bsspc-1)
            fputs(leader, outfile);
        }
        else
          if (i<bsspc-1)
            fputc(',', outfile);
      }
      if (i&15)
        fputc('\n', outfile);
      break;
    case OUT_obj:
      write_THEADR(outfile,inname);
      write_LNAMES(outfile,"","CODE","BSS","TEXT","DATA",0);
      write_SEGDEF(outfile,bsspc,4,2,1);	/* text and data */
      write_SEGDEF(outfile,pc-bsspc,5,3,1);	/* .bss */
      write_EXTDEF(outfile,symtab);
      write_PUBDEF(outfile,symtab,bsspc);
      write_LEDATA(outfile,1,outbin,bsspc,symtab);
      write_MODEND(outfile,main_obj,start_ptr);
      break;
  }
  fclose(outfile);
  
  if (argc > 3)
  {
    FILE *mapfile = fopen(argv[3], "w");
    fprintf(mapfile, "%#x bytes generated, %#x bytes in file, %#x bytes total, %d symbols\n",
      generated_bytes, bsspc, pc, symcount);

    fprintf(mapfile, "\nStart Stop  Length Name Class\n");
    fprintf(mapfile, "%04XH %04XH %04XH  code code\n", 0, pc-1, pc);

    fprintf(mapfile, "\nAddress    Symbols by Name\n\n");
    for (s = symtab; s; s=s->next)
      if (!istemp(s->name, 0))
        fprintf(mapfile, "0000:%04X  %s (%c)\n", s->value, s->name, SYMTYPES[s->type]);
    fprintf(mapfile, "\nAddress    Symbols by Value\n\n");
    sortsyms(scmp_n);
    for (s = symtab; s; s=s->next)
      if (!istemp(s->name, 0))
        fprintf(mapfile, "0000:%04X  %s (%c)\n", s->value, s->name, SYMTYPES[s->type]);
    current_map_file = 0;
    for (i=0; i<num_lineaddr; i++)
    {
      if (current_map_file != lineaddr[i].name)
      {
	current_map_file = lineaddr[i].name;
	if ((i & 3) != 3)
	  fprintf(mapfile, "\n");
	fprintf(mapfile, "\nLine numbers for (%s)\n", current_map_file);
	num_lineaddr-=i;
	lineaddr+=i;
	i=0;
      }
      fprintf(mapfile, "%5d 0000:%04X", lineaddr[i].line, lineaddr[i].addr);
      if ((i & 3) == 3)
        fputc('\n', mapfile);
      else
        fputc(' ', mapfile);
    }
    fputc('\n', mapfile);
    fclose(mapfile);
  }
  return 0;
}

void djerror(char *s)
{
  fprintf(stderr, "%s:%d: %s\n", inname, lineno, s);
  strbuf[strbuflen] = 0;
  total_errors++;
}

void yyerror(char *s)
{
  djerror(s);
  fprintf(stderr, "%s:%d: Last token was `%s' (%s)\n", inname, lineno, last_token, yytname[(unsigned char)yytranslate[last_tret]]);
}

void
shxd_error(int opcode)
{
  char *bad_op;
  char *good_op;
  char msg[80];

  if (opcode == 4)
  {
    bad_op = "shld";
    good_op = "dshl";
  }
  else
  {
    bad_op = "shrd";
    good_op = "dshr";
  }
  sprintf(msg, "Obsolete use of `%s' detected.  Use `%s' instead.", bad_op, good_op);
  djerror(msg);
}

Symbol *get_symbol(char *name, int create)
{
  Symbol *s;
  for (s=symtab; s; s=s->next)
    if (strcmp(name, s->name) == 0)
      return s;
  if (!create)
    return 0;
  s = (Symbol *)malloc(sizeof(Symbol));
  s->next = symtab;
  symtab = s;
  s->name = (char *)malloc(strlen(name)+1);
  strcpy(s->name, name);
  s->value = 0;
  s->defined = 0;
  s->external = 0;
  s->public = 0;
  s->patches = 0;
  s->first_used = lineno;
  s->type = SYM_unknown;
  return s;
}

void
add_enum_element(Symbol * s)
{
  if (islocal(s->name) || istemp(s->name, 0))
  {
    djerror("Cannot have local or temporary labels within an enum");
  }
  else
  {
    char *id = alloca(strlen(s->name) + strlen(struct_sym) + 2);
    strcpy(id, struct_sym);
    strcat(id, ".");		/* should this be "_" to disambiguate enums
				   from structs? */
    strcat(id, s->name);
    if (!s->defined && !s->patches)
    {
      /* only delete fresh symbols */
      destroy_symbol(s, 0);
    }
    set_symbol(get_symbol(id, 1), struct_pc++);
  }
}

void add_struct_element(Symbol *s)
{
  if (islocal(s->name) || istemp(s->name,0)) {
    djerror("Cannot have local or temporary labels within a structure");
  } else {
    char *id=alloca(strlen(s->name)+strlen(struct_sym)+2);
    strcpy(id,struct_sym);
    strcat(id,".");
    strcat(id,s->name);
    if (!s->defined && !s->patches) {
      /* only delete fresh symbols */
      destroy_symbol(s,0);
    }
    if (struct_tp=='s') {
      /* .struct */
      set_symbol(get_symbol(id,1),struct_pc);
    } else {
      /* .union */
      set_symbol(get_symbol(id,1),0);
    }
  }
}

int is_structure(Symbol *s)
{
  char *n=s->name;
  size_t l=strlen(n);
  if (!s->next) {
    /* the elements of a struct or union always follow the symbol */
    return 0;
  }
  s=s->next;
  if (strncmp(n,s->name,l) || s->name[l]!='.') {
    /* Structure elements always have the structure name followed by a period before
     * the element name.
     */
    return 0;
  }
  return 1;
}

int set_structure_symbols(Symbol *ele, Symbol *struc, int tp, int base, int type)
{
  if (!struc->defined) {
    djerror("undefined symbol used in struct");
    return 0;
  }
  if (!is_structure(struc)) {
    djerror("symbol must be a .struct or .union");
    return 0;
  }
  set_symbol(ele,base)->type|=type;
  {
    int sLen=strlen(struc->name);
    int eLen=strlen(ele->name);
    Symbol *s=struc->next;
    while (s && !strncmp(s->name,struc->name,sLen) && s->name[sLen]=='.') {
      char *id=alloca(strlen(s->name)-sLen+eLen+1);
      strcpy(id,ele->name);
      strcpy(id+eLen,s->name+sLen);
      set_symbol(get_symbol(id,1),base+s->value)->type|=type;
      s=s->next;
    }
  }
  return 1;
}

void emit_struct(Symbol *ele, int tp, Symbol *struc)
{
  int i;

  if (set_structure_symbols(ele,struc,tp,pc,(pc?SYM_data:SYM_code)))
    for (i = 0; i < struc->value; i++)
      emitb(0); /* only unitialized structures supported */
}

void emit_struct_abs(Symbol *ele, int tp, Symbol *struc, int offset)
{
  /* NOTE: Does not actually emit any bytes! (by design) */
  set_structure_symbols(ele,struc,tp,offset,(offset?SYM_data:SYM_code));
}

void build_struct(Symbol *ele, int tp, Symbol *struc)
{
  if (ele && (islocal(ele->name) || istemp(ele->name,0))) {
    djerror("Cannot have local or temporary labels within a structure");
  } else {
    char *id=alloca((ele?strlen(ele->name):0)+strlen(struct_sym)+2);
    Symbol *sym;
    strcpy(id,struct_sym);
    if (ele) {
      strcat(id,".");
      strcat(id,ele->name);
      if (!ele->defined && !ele->patches) {
	/* only delete fresh symbols */
	destroy_symbol(ele,0);
      }
    }
    sym=get_symbol(id,1);
    if (!ele) {
	symtab=symtab->next;
	sym->next=0;
    }
    set_structure_symbols(sym,struc,tp,(struct_tp=='s')?struct_pc:0,SYM_abs);
    if (!ele) {
      destroy_symbol(sym,0);
    }
    if (struct_tp=='s')
      struct_pc+=struc->value;
    else
      struct_pc=MAX(struct_pc,struc->value);
  }
}
					
Symbol *set_symbol(Symbol *s, int value)
{
  if (!islocal(s->name) && !istemp(s->name,0))
    destroy_locals();
  if (istemp(s->name, 'b'))
    s->defined = 0;
  if (s->defined)
    fprintf(stderr,"%s:%d: warning: symbol %s redefined\n", inname, lineno, s->name);
  s->value = value;
  s->defined = 1;
  while (s->patches)
  {
    int v=0, o=0;
    unsigned char *cp;
    Patch *p = s->patches;
    s->patches = s->patches->next;
    switch (p->rel)
    {
    case REL_abs:
    case REL_abs32:
      v = value;
      break;
    case REL_16:
      v = value - p->location - 2;
      break;
    case REL_8:
      v = value - p->location - 1;
      break;
    }
    cp = outbin + p->location;
    switch (p->rel)
    {
    case REL_abs32:
      o = (signed long)(cp[0] | (cp[1] << 8) | (cp[2] << 16) | (cp[3] << 24));
      break;
    case REL_abs:
    case REL_16:
      o = (signed short)(cp[0] | (cp[1] << 8));
      break;
    case REL_8:
      o = (signed char)(cp[0]);
      break;
    }
    o += v;
    switch (p->rel)
    {
    case REL_abs32:
      cp[3] = o>>24;
      cp[2] = o>>16;
      /* fall through */
    case REL_abs:
    case REL_16:
      cp[1] = o>>8;
      cp[0] = o;
      break;
    case REL_8:
      if (o > 127 || o < -128)
      {
	/* So far away from me
	   So far I just can't see
	   So far away from me
	   You're so far away from me
	   -- from `So far away' by Mark Knopfler.  */
	fprintf(stderr, "%s:%d: 8-bit relocation too big (%d); use long form\n", p->filename, p->lineno, o);
	total_errors++;
      }
      cp[0] = o;
      break;
    }
    free(p);
  }
  if (istemp(s->name, 'f'))
    s->defined = 0;
  return s;
}

void destroy_symbol(Symbol *sym, int undef_error)
{
  Symbol **s=&symtab;
  while (*s)
  {
    if (*s==sym)
    {
      Symbol *_s=*s;
      if (undef_error && !_s->defined && _s->patches)
      {
	Patch *p,*_p;
	for (p=_s->patches; p; p=_p) {
	  fprintf(stderr,"%s:%d: undefined symbol `%s'\n", p->filename, p->lineno, _s->name);
	  _p=p->next;
	  free(p);
	}
	undefs++;
      }
      _s=(*s)->next;
      free(*s);
      *s=_s;
    }
    else
    {
      s=&(*s)->next;
    }
  }
}

void destroy_locals(void)
{
  Symbol **s=&symtab;
  while (*s)
  {
    if (islocal((*s)->name))
    {
      Symbol *_s=*s;
      if (!_s->defined && _s->patches)
      {
	Patch *p,*_p;
	for (p=_s->patches; p; p=_p) {
	  fprintf(stderr,"%s:%d: undefined symbol `%s'\n", p->filename, p->lineno, _s->name);
	  _p=p->next;
	  free(p);
	}
	undefs++;
      }
      _s=(*s)->next;
      free(*s);
      *s=_s;
    }
    else
    {
      s=&(*s)->next;
    }
  }
}

void sortsyms(int (*sortf)(void const *,void const *))
{
  int ns, i;
  Symbol *s, **st;
  if (!symtab)
    return;
  for (s=symtab, ns=0; s; s=s->next)
    ns ++;
  st = (Symbol **)malloc(sizeof(Symbol *) * ns);
  for (s=symtab, ns=0; s; s=s->next, ns++)
    st[ns] = s;
  qsort(st, ns, sizeof(Symbol *), sortf);
  for (i=0; i<ns-1; i++)
    st[i]->next = st[i+1];
  st[i]->next = 0;
  symtab = st[0];
  free(st);
}

void emit(void *ptr, int len)
{
  while (pc + len > outsize)
  {
    outsize += 512;
    outbin = realloc(outbin, outsize);
  }
  set_lineaddr();
  memcpy(outbin+pc, ptr, len);
  pc += len;
}

void emitb(int b)
{
  unsigned char c = b;
  emit(&c, 1);
}

void emitw(int w)
{
  emitb(w);
  emitb(w>>8);
}

void emitd(long d)
{
  emitw(d);
  emitw(d>>16);
}

void emits(Symbol *s, int offset, int rel)
{
  Patch *p;
  int v;
  if (s->defined)
  {
    switch (rel)
    {
    case REL_abs32:
      v = s->value + offset;
      emitd(v);
      break;
    case REL_abs:
      v = s->value + offset;
      emitw(v);
      break;
    case REL_abs8:
      v = s->value + offset;
      emitb(v);
      break;
    case REL_16:
      v = s->value - pc - 2 + offset;
      emitw(v);
      break;
    case REL_8:
      v = s->value - pc - 1 + offset;
      if (v < -128 || v > 127)
      {
	fprintf(stderr, "%s:%d: 8-bit relocation too big (%d); use long form\n", inname, lineno, v);
	total_errors++;
      }
      emitb(v);
      break;
    }
    return;
  }
  p = (Patch *)malloc(sizeof(Patch));
  p->next = s->patches;
  s->patches = p;
  p->location = pc;
  p->lineno = lineno;
  p->filename = inname;
  p->rel = rel;
  switch (rel)
  {
  case REL_abs32:
    emitd(offset);
    break;
  case REL_abs:
  case REL_16:
    emitw(offset);
    break;
  case REL_8:
    if (offset < -128 || offset > 127)
    {
      fprintf(stderr, "%s:%d: 8-bit relocation offset too big (%d); use long form\n", inname, lineno, offset);
      total_errors++;
    }
    emitb(offset);
    break;
  }
}

void modrm(int mod, int reg, int rm)
{
  emitb((mod<<6) | (reg<<3) | rm);
}

int findreg(int regbits)
{
  int i=0;
  while (regbits) {
    regbits>>=1;
    i++;
  }
  return i?i-1:4;
}

int findscl(int sclbits)
{
  static int bits[]={0,0,1,0,2,0,0,0,3};
  return bits[sclbits];
}

int nooffset(int mbyte, int needsib)
{
    if (_modrm.offset == 0 && _modrm.nsyms == 0) {
      emitb(mbyte);
      if (needsib)
	emitb(mbyte>>8);
      if (mbyte&0100)
        emitb(0);
      _modrm.nsyms = _modrm.addr32 = _modrm.addr16 = _modrm.offset = _modrm.regs = 0;
      return 1;
    }
    return 0;
}

int reg2mbyte[] = { 0x48, 0x88, 0x60, 0xa0, 0x40, 0x80, 0x20, 0x08 };

void reg(int which)
{
  int i;
  int v;
  int mbyte = which << 3;
  int needsib = 0;

  if (_modrm.regs == 0) {
    /* This handles the case of displacement only addressing (no register
     * ofsets)
     */
    mbyte=movacc ? movacc : mbyte + (_modrm.addr32 ? 5 : 6);
    movacc=0;
  } else if (_modrm.regs == 0x20 && _modrm.offset == 0 && _modrm.nsyms == 0) {
    /* [bp+0] */
    nooffset(mbyte|0106,0);
    return;
  } else {
    if (_modrm.addr32) {
      if (_modrm.addr32&0xff) {
	int sib= findreg( _modrm.addr32     &0xff)    |
	        (findreg((_modrm.addr32>>8 )&0xff)<<3)|
	        (findscl((_modrm.addr32>>16)&0x0f)<<6);
	if (sib==045 && _modrm.offset == 0 && _modrm.nsyms == 0) {
	  /* [ebp+0] */
	  nooffset(mbyte|0104|(045<<8),1);
	  return;
	} else if (sib==044) {
	  /* [esp] */
	  mbyte|=(sib<<8)|004;
	  needsib=1;
	} else if ((sib&070)==0040) {
	  /* no index */
	  mbyte|=sib&007;
	} else if ((sib&007)==0005) {
	  /* ebp is base */
	  mbyte|=(sib<<8)|004;
	  needsib=1;
	  if (nooffset(mbyte|0100,1))
	    return;
	} else {
	  mbyte|=(sib<<8)|004;
	  needsib=1;
	}
	if (nooffset(mbyte,needsib))
	  return;
	mbyte|=0200;
      } else {
	int sib=(005				     )|
	        (findreg((_modrm.addr32>>8 )&0xff)<<3)|
		(findscl((_modrm.addr32>>16)&0x0f)<<6);
	mbyte&=070;
	mbyte|=(sib<<8)|004;
	needsib=1;
	if (nooffset(mbyte,1))
	  return;
      }
    } else {
      /* 16 bit addressing */
      for (i=0; i<8; i++)
	if (reg2mbyte[i] == _modrm.regs)
	{
	  mbyte |= i;
	  break;
	}
      if (i == 8)
      {
	fprintf(stderr,"%s:%d: Invalid registers in R/M\n", inname, lineno);
	total_errors ++;
      }
      if (nooffset(mbyte,needsib))
	return;
      mbyte|=0200;
    }
  }

  v = _modrm.offset;
  for (i=0; i<_modrm.nsyms; i++)
  {
    Symbol *s = _modrm.syms[i];
    if (s->defined)
      v += s->value;
    else
    {
      Patch *p;
      p = (Patch *)malloc(sizeof(Patch));
      p->next = s->patches;
      s->patches = p;
      p->location = pc+1+needsib; /* ALL bytes emitted below, accounts for yet to be emitted mbyte */
      p->lineno = lineno;
      p->filename = inname;
      p->rel = _modrm.addr32 ? REL_abs32 : REL_abs;
      _modrm.regs=0; /* force offset field to be full size (2/4 bytes rather than 1) */
    }
  }
  if (_modrm.regs && v>=-128 && v<=127) {
    emitb(mbyte^0300); /* change mod from 2/4 ((d)word offset) to 1 (byte offset) */
    if (needsib)
      emitb(mbyte>>8);
    emitb(v);
  } else {
    emitb(mbyte);
    if (needsib)
      emitb(mbyte>>8);
    if (_modrm.addr32)
      emitd(v);
    else
      emitw(v);
  }

  _modrm.nsyms = _modrm.addr32 = _modrm.addr16 = _modrm.offset = _modrm.regs = 0;
}

void addr32(int sib)
{
  char *err=0;

  if (_modrm.addr16) {
    err="Cannot mix 16 and 32 bit addressing";
  } else {
    if (!_modrm.addr32) emitb(0x67);
    _modrm.addr32|=0x1000000;
    if ((sib&0xf00)>0x100) {
      if ((sib&0xff)==0x10) {
	err="esp cannot be scaled";
      } else if (_modrm.addr32&0xff00) {
	err="scaled index already used";
      } else {
	_modrm.addr32|=sib<<8;
      }
    } else {
      if (!(_modrm.addr32&0xff)) {
	_modrm.addr32|=(sib&0xff)|0x1000000;
      } else if (!(_modrm.addr32&0xff00)) {
	if ((sib&0xff)==0x10) {
	  if ((_modrm.addr32&0xff)==0x10) {
	    err="esp cannot be the index";
	  } else {
	    _modrm.addr32=(_modrm.addr32&0xff)<<8;
	    _modrm.addr32|=(sib&0xff)|0x1010000;
	  }
	} else {
	  _modrm.addr32|=sib<<8;
	}
      } else {
	err="scaled index already used";
      }
    }
  }
  if (err) {
    djerror(err);
    _modrm.nsyms = _modrm.addr32 = _modrm.addr16 = _modrm.offset = _modrm.regs = 0;
  } else {
    _modrm.regs=-1;
  }
}

int yylex(void)
{
  last_tret = yylex1();
  return last_tret;
}

static struct {
  char c1, c2;
  int token;
} twochars[] = {
  {'=', '=', '='},
  {'>', '=', OP_GE},
  {'<', '=', OP_LE},
  {'<', '>', OP_NE},
  {'!', '=', OP_NE},
  {'&', '&', OP_AND},
  {'|', '|', OP_OR},
  {'<', '<', OP_SHL},
  {'>', '>', OP_SHR}
};

int yylex1(void)
{
  int c, c2, i, oldc;
  struct opcode *opp, op;

  do {
    c = fgetc(infile);
  } while (c == ' ' || c == '\t');

  switch (c)
  {
    case EOF:
      if (file_stack)
      {
        FileStack *tmp = file_stack;
        fclose(infile);
        /*free(inname);*/ /* needed by lineaddr_s and Patch */
        lineno = file_stack->line + 1; /* Correct for .include line */
        infile = file_stack->f;
        inname = file_stack->name;
        file_stack = file_stack->prev;
        free(tmp);
        return yylex1();
      }
      return 0;

    case 'a' ... 'z':
    case 'A' ... 'Z':
    case '_':
    case '$':
    case '.':
    case '@':
    case '?':
      if (c=='?')
	{
	  strbuf[0]=c;
	  fscanf(infile, "%[a-zA-Z0-9_$.@]", strbuf+1);
	}
      else
	{
	  ungetc(c, infile);
	  fscanf(infile, "%[a-zA-Z0-9_$.@]", strbuf);
	}
      strcpy(last_token, strbuf);
      if (strcmp(strbuf, ".") == 0)
        return PC;
      op.name = strbuf;
      opp = bsearch (&op,
		     opcodes, 
		     sizeof (opcodes) / sizeof (opcodes[0]),
		     sizeof (opcodes[0]),
		     opcode_compare);
      if (opp)
	{
	  yylval.i = opp->attr;
	  return opp->token;
	}
      else
	{
	  yylval.sym = get_symbol(strbuf,1);
	  return yylval.sym->defined ? KID : UID;
	}

    case '0' ... '9':
    #ifdef __linux
      /* fscanf "%i" doesn't work reliably with libc5.4.44 for large hex nubmers */
      if (c == '0')
        {
	  /* octal or hex */
	  yylval.i = 0;
	  c = fgetc (infile);
	  if (c == 'x' || c == 'X')
	    {
	      while (1)
		{
		  c = fgetc (infile);
		  if (!isxdigit (c))
		    {
		      ungetc(c, infile);
		      break;
		    }
		  c = toupper (c);
		  if (c > '9')
		    c -= 'A' - '9' - 1;
		  yylval.i *= 16;
		  yylval.i += c - '0';
		}
	    }
	  else if (c >= '0' && c <= '7')
	    {
	      yylval.i = c - '0';
	      while (1)
		{
		  c = fgetc (infile);
		  if (!(c >= '0' && c <= '7'))
		    {
		      ungetc(c, infile);
		      break;
		    }
		  yylval.i *= 8;
		  yylval.i += c - '0';
		}
	    }
	  else
	    ungetc(c, infile);
	}
      else
        {
	  yylval.i = c - '0';
	  while (1)
	    {
	      c = fgetc (infile);
	      if (!isdigit (c))
		{
		  ungetc(c, infile);
		  break;
		}
	      yylval.i *= 10;
	      yylval.i += c - '0';
	    }
        }
    #else
      ungetc(c, infile);
      fscanf(infile, "%i", &(yylval.i));
    #endif
      sprintf(last_token, "%d", yylval.i);
      return NUMBER;
      break;

    case '>':
    case '<':
    case '!':
    case '&':
    case '|':
    case '=':
      c2 = fgetc (infile);
      for (i = 0; i < 9; i++)
	if (c == twochars[i].c1 && c2 == twochars[i].c2)
	  return twochars[i].token;
      ungetc (c2, infile);
      return c;

    case '"':
    case '\'':
      oldc = c;
      i = 0;
      while (1)
      {
        c = fgetc(infile);
        if (c == oldc)
        {
          strcpy(last_token, strbuf);
          strbuflen = i;
          if (strbuflen == 1)
          {
            yylval.i = strbuf[0];
            return NUMBER;
          }
          return STRING;
	}
        switch (c)
        {
          case '\\':
            switch (c = fgetc(infile))
            {
              case '0':
                strbuf[i++] = 0;
                break;
              case 'n':
                strbuf[i++] = '\n';
                break;
              case 'r':
                strbuf[i++] = '\r';
                break;
              case 't':
                strbuf[i++] = '\t';
                break;
              default:
                strbuf[i++] = c;
                break;
            }
            break;
          default:
            strbuf[i++] = c;
            break;
        }
      }
      abort ();
    case ';':
      while (fgetc(infile) != '\n');
      c = '\n';
      /* Fall through.  */
    case '\n':
      strcpy(last_token, "NL");
      return c;
    default:
      sprintf(last_token, "<%c>", c);
      return c;
  }
}

int istemp(char *symname, char which)
{
  if (symname[0] != '@') return 0;
  if (which)
  {
    if (symname[1] != which) return 0;
  }
  else
  {
    if (symname[1] != 'f' && symname[1] != 'b') return 0;
  }
  if (!isdigit((unsigned char)symname[2])) return 0;
  if (symname[3]) return 0;
  return 1;
}

int islocal(char *symname)
{
  if (symname[0]!='?') return 0;
  return 1;
}

void do_sreg_pop(int sreg)
{
  switch (sreg)
  {
    case 0: /* es */
      emitb(0x07);
      break;
    case 1: /* cs */
      djerror("Cannot pop CS");
      break;
    case 2: /* ss */
      emitb(0x17);
      break;
    case 3: /* ds */
      emitb(0x1f);
      break;
    case 4: /* fs */
      emitb(0x0f);
      emitb(0xa1);
      break;
    case 5: /* gs */
      emitb(0x0f);
      emitb(0xa9);
      break;
  }
}

void do_sreg_push(int sreg)
{
  switch (sreg)
  {
    case 0: /* es */
      emitb(0x06);
      break;
    case 1: /* cs */
      emitb(0x0e);
      break;
    case 2: /* ss */
      emitb(0x16);
      break;
    case 3: /* ds */
      emitb(0x1e);
      break;
    case 4: /* fs */
      emitb(0x0f);
      emitb(0xa0);
      break;
    case 5: /* gs */
      emitb(0x0f);
      emitb(0xa8);
      break;
  }
}

void set_lineaddr()
{
  static int last_lineno = -1;
  if (lineno == last_lineno)
    return;
  last_lineno = lineno;
  if (num_lineaddr == max_lineaddr)
  {
    max_lineaddr += 32;
    if (lineaddr)
      lineaddr = (lineaddr_s *)realloc(lineaddr, max_lineaddr * sizeof(lineaddr_s));
    else
      lineaddr = (lineaddr_s *)malloc(max_lineaddr * sizeof(lineaddr_s));
  }
  lineaddr[num_lineaddr].line = lineno;
  lineaddr[num_lineaddr].addr = pc;
  lineaddr[num_lineaddr].name = inname;
  num_lineaddr++;
}

void do_align(int p2, int val)
{
  size_t offset;

  if (image_type == OUT_com)
    offset = 0;
  else
    offset = EXE_HEADER_SIZE;

  last_align_begin = pc;
  while ((pc+offset) % p2)
    emitb(val);
  last_align_end = pc;
}

void add_copyright(char *buf)
{
  char *tmp;
  if (copyright == 0)
  {
    copyright = (char *)malloc(strlen(buf)+1);
    strcpy(copyright, buf);
    return;
  }
  tmp = (char *)malloc(strlen(copyright) + strlen(buf) + 3);
  strcpy(tmp, copyright);
  strcat(tmp, "\r\n");
  strcat(tmp, buf);
  free(copyright);
  copyright = tmp;
}

void add_rcs_ident(char *buf)
{
  char tmp[500];
  time_t now;
  struct tm *tm;
  time(&now);
  tm = localtime(&now);
  sprintf(tmp, "%cId: %s built %04d-%02d-%02d %02d:%02d:%02d by djasm $\n",
	  '$', inname,
	  tm->tm_year + 1900,
	  tm->tm_mon + 1,
	  tm->tm_mday,
	  tm->tm_hour,
	  tm->tm_min,
	  tm->tm_sec);
  add_copyright(tmp);
  sprintf(tmp, "@(#) %s built %04d-%02d-%02d %02d:%02d:%02d by djasm\n",
	  inname,
	  tm->tm_year + 1900,
	  tm->tm_mon + 1,
	  tm->tm_mday,
	  tm->tm_hour,
	  tm->tm_min,
	  tm->tm_sec);
  add_copyright(tmp);
}

void set_out_type(char *t)
{
  int i;
  for (i=0; ext_types[i]; i++)
  {
    if (strcmp(ext_types[i], t) == 0)
    {
      out_type = i;
      return;
    }
  }
  fprintf(stderr,"Unknown output type: `%s'\n", t);
}

void set_image_type(char *t)
{
  int i;
  for (i=0; ext_types[i]; i++)
  {
    if (strcmp(ext_types[i], t) == 0)
    {
      if (i == OUT_com && image_type != OUT_com)
      {
        if (pc)
        {
          fprintf(stderr, "Cannot make com file without .type \"com\"\n");
          exit(1);
        }
        while (pc < 0x100)
          emitb(0x90);
      }
      image_type = i;
      return;
    }
  }
  fprintf(stderr,"Unknown output type: `%s'\n", t);
}

void do_include(char *fname)
{
  FILE *f;
  FileStack *fs;
  
  f = fopen(fname, "r");
  if (!f)
  {
    fprintf(stderr, "%s:%d: error openning `%s'", inname, lineno, fname);
    perror("");
    return;
  }
  fs = (FileStack *)malloc(sizeof(FileStack));
  fs->line = lineno;
  fs->prev = file_stack;
  fs->f = infile;
  fs->name = inname;
  file_stack = fs;

  infile = f;
  inname = (char *)malloc(strlen(fname)+1);
  strcpy(inname, fname);
  lineno = 1;
}

/* #define DEBUG_RELOC */

void do_linkcoff (char *filename)
{
  long len;
  int f;
  char *data, *p;
  char *coff_filename;
  FILHDR *header;
  SCNHDR *f_thdr;		/* Text section header */
  SCNHDR *f_dhdr;		/* Data section header */
  SCNHDR *f_bhdr;		/* Bss section header */
/*  AOUTHDR f_ohdr;*/		/* Optional file header (a.out) */
  SYMENT *symbol;
  RELOC *rp;
  int cnt;
  size_t i;
  void *base;
  int textbase, database, bssbase/*, delta*/;
  char smallname[9];
  unsigned char *cp;

  f = open (filename, O_RDONLY | O_BINARY);
  if (f < 0)
    {
      fprintf(stderr, "%s:%d: error openning `%s'", inname, lineno, filename);
      perror("");
      return;
    }
  len = lseek (f, 0L, SEEK_END);
  lseek (f, 0L, SEEK_SET);
  data = alloca (len);
  read (f, data, (unsigned)len);
  close (f);

  header = (FILHDR *) data;
  f_thdr = (void *)data + sizeof (FILHDR) + header->f_opthdr;
  f_dhdr = f_thdr + 1;
  f_bhdr = f_dhdr + 1;
  if (I386BADMAG (*header)
      || header->f_nscns != 3
      || strcmp (f_thdr->s_name, _TEXT)
      || strcmp (f_dhdr->s_name, _DATA)
      || strcmp (f_bhdr->s_name, _BSS))
    {
      fprintf (stderr, "%s:%d: `%s' is not a valid COFF file.\n", inname, lineno, filename);
      return;
    }

  textbase = pc;
  emit(data + f_thdr->s_scnptr, f_thdr->s_size);
  database = pc;
  emit(data + f_dhdr->s_scnptr, f_dhdr->s_size);
  bssbase = pc;
  for (i = 0; i < f_bhdr->s_size; i++)
    emitb (0);

#ifdef DEBUG_RELOC
  printf (stderr,"textbase is at %04x\n", textbase);
  printf (stderr,"database is at %04x\n", database);
  printf (stderr,"bssbase  is at %04x\n", bssbase);
#endif

  symbol = (void *) data + header->f_symptr;
  base = (void *) symbol + header->f_nsyms * SYMESZ;
  coff_filename = strdup (filename);
  for (cnt = header->f_nsyms; cnt > 0; symbol++, cnt--)
    {
      if (symbol->e.e.e_zeroes == 0)
	p = base + symbol->e.e.e_offset;
      else
	strncpy (p = smallname, symbol->e.e_name, 8),
	p[8] = 0;

      switch (symbol->e_sclass)
	{
	case C_EXT:
	  switch (symbol->e_scnum)
	    {
	    case 1:
	      set_symbol (get_symbol (p, 1),
			  textbase + symbol->e_value)->type |= SYM_code;
	      break;
	    case 2:
	      set_symbol (get_symbol (p, 1),
			  textbase + symbol->e_value)->type |= SYM_data;
	      break;
	    case 3:
	      set_symbol (get_symbol (p, 1),
			  textbase + symbol->e_value)->type |= SYM_data;
	      break;
	    case N_UNDEF:
	      if (symbol->e_value == 0)
		/*0*/;  /* Nothing -- external reference.  */
	      else if (!get_symbol (p, 0))
		{
		  /* New common variable.  */
		  set_symbol (get_symbol (p, 1), pc)->type |= SYM_data;
		  for (i = 0; i < symbol->e_value; i++)
		    emitb (0);
		}
	      break;
	    }
	  break;
	}
      cnt -= symbol->e_numaux;
      symbol += symbol->e_numaux;
    }

  symbol = (void *) data + header->f_symptr;
  for (i = 0; i < 2; i++)
    {
      if (i == 0)
	rp = (RELOC *) (data + f_thdr->s_relptr),
	cnt = f_thdr->s_nreloc;
      else
	rp = (RELOC *) (data + f_dhdr->s_relptr),
	cnt = f_dhdr->s_nreloc;

      for (; cnt > 0; cnt--, rp++)
	{
	  Symbol *s=0;
	  unsigned char *vaddr_ptr=outbin + textbase + rp->r_vaddr;
	  int vaddr;
	  int delta;

	  vaddr=vaddr_ptr[0] | (vaddr_ptr[1] << 8) |
		(vaddr_ptr[2] << 16) | (vaddr_ptr[3] << 24);


	  if (symbol[rp->r_symndx].e.e.e_zeroes == 0)
	    p = base + symbol[rp->r_symndx].e.e.e_offset;
	  else
	    strncpy (p = smallname, symbol[rp->r_symndx].e.e_name, 8),
	    p[8] = 0;

#ifdef DEBUG_RELOC
	  s = get_symbol (p, 0);
	  printf ("ofs=%04x  typ=%02x  sec=%d"
		  "  val=%08x  data=%08x"
		  "  name=%s\n",
		  rp->r_vaddr + textbase,
		  rp->r_type,
		  symbol[rp->r_symndx].e_scnum,
		  s ? s->value : 0, 
		  vaddr,
		  p);
#endif
	  if (!strcmp (p, _TEXT))
	    delta = textbase;
	  else if (!strcmp (p, _DATA))
	    delta = textbase;
	  else if (!strcmp (p, _BSS))
	    delta = textbase;
	  else
	    {
	      s = get_symbol (p, 1);
	      if (!s->defined)
		{
		  Patch *pat = (Patch *) malloc (sizeof (Patch));

		  if (rp->r_type == RELOC_REL32)
		    fprintf (stderr,"%s:%d: warning:"
			     "Call from COFF file to (yet) undefined "
			     "destination, %s, is not supported.\n", inname, lineno, p);
		  pat->next = s->patches;
		  s->patches = pat;
		  pat->location = textbase + rp->r_vaddr;
		  pat->lineno = -1;
		  pat->filename = coff_filename;
		  pat->rel = REL_abs32;
		}
	    }

	  switch (rp->r_type)
	    {
	    case RELOC_ADDR32:
	      if (symbol[rp->r_symndx].e_scnum > 0)
		delta = textbase;
	      else
		delta = s->value - symbol[rp->r_symndx].e_value;
	      break;
	    case RELOC_REL32:
	      if (symbol[rp->r_symndx].e_scnum > 0)
		delta = 0;
	      else
		delta = s->value - textbase;
	      break;
	    default:
	      fprintf (stderr, "%s:%d:"
		       "COFF file %s contains bad relocation "
		       "entry type (0x%02x).\n",
		       inname, lineno, filename, rp->r_type);
	      delta = 0;
	    }
	  cp = (unsigned char *)(outbin + textbase + rp->r_vaddr);
	  vaddr += delta;
	  vaddr_ptr[0]=vaddr;
	  vaddr_ptr[1]=vaddr>>8;
	  vaddr_ptr[2]=vaddr>>16;
	  vaddr_ptr[3]=vaddr>>24;
	}
    }
}

int write_BYTE(unsigned char byte, FILE *outfile, unsigned char *checksum)
{
  fputc(byte,outfile);
  *checksum-=byte;
  return 1;
}

int write_WORD(unsigned short word, FILE *outfile, unsigned char *checksum)
{
  return write_BYTE(word&0xff,outfile,checksum) +
	 write_BYTE((word>>8)&0xff,outfile,checksum);
}

int write_STRING(char *str, FILE *outfile, unsigned char *checksum)
{
  int length=0;
  int len=strlen(str);

  if (len>254)
    len=254;
  length+=write_BYTE(len,outfile,checksum);
  while (len--)
    length+=write_BYTE(*str++,outfile,checksum);
  return length;
}

int write_INDEX(int index, FILE *outfile, unsigned char *checksum)
{
  if (index>127)
    return write_WORD(index+0x8000,outfile,checksum);
  else
    return write_BYTE(index,outfile,checksum);
}

void write_THEADR(FILE *outfile, char *inname)
{
  unsigned char checksum=0;
  off_t lptr,cptr;
  int length;

  write_BYTE(0x80,outfile,&checksum);
  /* reserve space for the length field */
  lptr=ftell(outfile);
  write_WORD(0,outfile,&checksum); /* does not change checksum */

  length=write_STRING(inname,outfile,&checksum);
  cptr=ftell(outfile);
  fseek(outfile,lptr,0/*SEEK_SET*/);
  write_WORD(length+1,outfile,&checksum); /* plus 1 for checksum */
  fseek(outfile,cptr,0/*SEEK_SET*/);
  write_BYTE(checksum,outfile,&checksum); /* sets checksum to 0 */
}

void write_LNAMES(FILE *outfile, ...)
{
  va_list names;
  int written=0;
  int length=0;
  off_t lenptr=0;
  unsigned char checksum=0;
  char *name;

  va_start(names,outfile);
  name=va_arg(names,char*);
  
  while (name)
    {
      int len=strlen(name);
      /* truncate names to 254 characters (omf limitation) */
      if (len>254)
	len=254;
      /* make sure the record doesn't overflow */
      if (length+len>1020)
	{
	  off_t cptr=ftell(outfile);
	  fseek(outfile,lenptr,SEEK_SET);
	  write_WORD(length+1,outfile,&checksum); /* plus 1 for checksum */
	  fseek(outfile,cptr,SEEK_SET);
	  write_BYTE(checksum,outfile,&checksum); /* sets checksum to 0 */
	  length=0;
	  written=0;
	}
      if (!written)
	{
	  written=1;
	  write_BYTE(0x96,outfile,&checksum);
	  /* reserve space for the length field */
	  lenptr=ftell(outfile);
	  write_WORD(0,outfile,&checksum); /* does not change checksum */
	}
      length+=write_STRING(name,outfile,&checksum);
      name=va_arg(names,char*);
    }
  if (written)
    {
      off_t cptr=ftell(outfile);
      fseek(outfile,lenptr,SEEK_SET);
      write_WORD(length+1,outfile,&checksum); /* plus 1 for checksum */
      fseek(outfile,cptr,SEEK_SET);
      write_BYTE(checksum,outfile,&checksum); /* sets checksum to 0 */
    }
}

void write_SEGDEF(FILE *outfile, int size, int name, int class, int overlay)
{
  unsigned char checksum=0;
  write_BYTE(0x98,outfile,&checksum);
  write_WORD(7+(name>127)+(class>127)+(overlay>127),outfile,&checksum);
  /* A=2 (word), C=2 (public), B=?, P=0 */
  write_BYTE(0x48|((size==0x1000)<<1),outfile,&checksum);
  write_WORD(size,outfile,&checksum);
  write_INDEX(name,outfile,&checksum);
  write_INDEX(class,outfile,&checksum);
  write_INDEX(overlay,outfile,&checksum);
  write_BYTE(checksum,outfile,&checksum); /* sets checksum to 0 */
}

void write_EXTDEF(FILE *outfile, Symbol *symtab)
{
  int written=0;
  int length=0;
  off_t lenptr=0;
  unsigned char checksum=0;
  Symbol *sym=symtab;

  while (sym)
    {
      if (sym->external)
        {
	  int len=strlen(sym->name);
	  /* truncate names to 254 characters (omf limitation) */
	  if (len>254)
	    len=254;
	  /* make sure the record doesn't overflow */
	  if (length+len>1020)
	    {
	      off_t cptr=ftell(outfile);
	      fseek(outfile,lenptr,SEEK_SET);
	      write_WORD(length+1,outfile,&checksum); /* plus 1 for checksum */
	      fseek(outfile,cptr,SEEK_SET);
	      write_BYTE(checksum,outfile,&checksum); /* sets checksum to 0 */
	      length=0;
	      written=0;
	    }
	  if (!written)
	    {
	      written=1;
	      write_BYTE(0x96,outfile,&checksum);
	      /* reserve space for the length field */
	      lenptr=ftell(outfile);
	      write_WORD(0,outfile,&checksum); /* does not change checksum */
	    }
	  length+=write_STRING(sym->name,outfile,&checksum);
	}
      sym=sym->next;
    }
  if (written)
    {
      off_t cptr=ftell(outfile);
      fseek(outfile,lenptr,SEEK_SET);
      write_WORD(length+1,outfile,&checksum); /* plus 1 for checksum */
      fseek(outfile,cptr,SEEK_SET);
      write_BYTE(checksum,outfile,&checksum); /* sets checksum to 0 */
    }
}

void write_PUBDEF(FILE *outfile, Symbol *symtab, int bss_start)
{
  int length=0;
  off_t lenptr=0,cptr;
  unsigned char checksum=0;
  Symbol *sym=symtab;

  while (sym)
    {
      if (sym->public && sym->defined) /* silently ignore undefined pubdefs */
        {
	  write_BYTE(0x96,outfile,&checksum);
	  /* reserve space for the length field */
	  lenptr=ftell(outfile);
	  write_WORD(0,outfile,&checksum); /* does not change checksum */

	  length+=write_INDEX(0,outfile,&checksum); /* group index */
	  if (sym->type&SYM_abs)
	    {
	      length+=write_INDEX(0,outfile,&checksum);
	      length+=write_WORD(0,outfile,&checksum);
	      length+=write_STRING(sym->name,outfile,&checksum);
	    }
	  else
	    {
	      if (sym->value>=bss_start)
		{
		  length+=write_INDEX(5,outfile,&checksum);
		  length+=write_STRING(sym->name,outfile,&checksum);
		  length+=write_WORD(sym->value-bss_start,outfile,&checksum);
		}
	      else
	        {
		  length+=write_INDEX(4,outfile,&checksum);
		  length+=write_STRING(sym->name,outfile,&checksum);
		  length+=write_WORD(sym->value,outfile,&checksum);
		}
	    }
	  write_INDEX(0,outfile,&checksum);

	  cptr=ftell(outfile);
	  fseek(outfile,lenptr,SEEK_SET);
	  write_WORD(length+1,outfile,&checksum); /* plus 1 for checksum */
	  fseek(outfile,cptr,SEEK_SET);
	  write_BYTE(checksum,outfile,&checksum); /* sets checksum to 0 */
	  length=0;
	}
      sym=sym->next;
    }
}

void write_LEDATA(FILE *outfile, int segment, unsigned char *outbin, int size,
		  Symbol *symtab)
{
  /* does not yet support relocations :( */
  int len;
  int maxlen=1020-(segment>127);
  int offset=0;
  int length=0;
  off_t lenptr,cptr;
  unsigned char checksum=0;

  while (size)
    {
      len=size;
      if (len>maxlen)
	len=maxlen;
      write_BYTE(0xa0,outfile,&checksum);
      /* reserve space for the length field */
      lenptr=ftell(outfile);
      write_WORD(0,outfile,&checksum); /* does not change checksum */

      length+=write_INDEX(segment,outfile,&checksum);
      length+=write_WORD(offset,outfile,&checksum);
      offset+=len;
      size-=len;
      while (len--)
        length+=write_BYTE(*outbin++,outfile,&checksum);
      cptr=ftell(outfile);
      fseek(outfile,lenptr,SEEK_SET);
      write_WORD(length+1,outfile,&checksum); /* plus 1 for checksum */
      fseek(outfile,cptr,SEEK_SET);
      write_BYTE(checksum,outfile,&checksum); /* sets checksum to 0 */
      length=0;
      /* !!! write out fixups (none generated yet as extern not yet implemented)
       * also need to make sure the last bytes of the ledata are not a partial
       * relocation site.
       */
    }
}

void write_MODEND(FILE *outfile, int main_obj, int start_ptr)
{
  unsigned char checksum=0;

  write_BYTE(0x8a,outfile,&checksum);
  if (main_obj)
    {
      write_WORD(6,outfile,&checksum); /* five bytes plus 1 for checksum */
      write_BYTE(0xc1,outfile,&checksum); /* main, start, fixup */
      /* the following is a FIXUPP record for the start address */
      write_BYTE(0x50,outfile,&checksum);
      write_INDEX(1,outfile,&checksum);
      write_WORD(start_ptr,outfile,&checksum);
    }
  else
    {
      write_WORD(2,outfile,&checksum); /* one byte plus 1 for checksum */
      write_BYTE(1,outfile,&checksum); /* fixup only (eh? why not 0?) */
    }
  write_BYTE(checksum,outfile,&checksum);
}
