javadis.cc

功能较全面的反汇编器：反汇编器ht-2.0.15.tar.gz

/*
 *	HT Editor
 *	javadis.cc
 *
 *	Copyright (C) 1999-2002 Stefan Weyergraf
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License version 2 as
 *	published by the Free Software Foundation.
 *
 *	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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <stdio.h>
#include <string.h>

#include "stream.h"
#include "tools.h"
#include "javadis.h"
#include "strtools.h"

/*
 *	CLASS javadis
 */

javadis::javadis(java_token_func tf, void *c)
{
	initialize(tf, c);
}

void javadis::initialize(java_token_func tf, void *c)
{
	token_func = tf;
	context = c;
}

dis_insn *javadis::decode(byte *code, int Maxlen, CPU_ADDR Addr)
{
	ocodep = code;
	codep = ocodep;
	maxlen = Maxlen;
	memset(&insn, 0, sizeof insn);
	addr = Addr.addr32.offset;
	insn.addr = Addr.addr32.offset;
	insn.invalid = false;

	insn.opcode = getbyte();
	if (insn.opcode == JAVA_WIDE_OPCODE) {
		insn.wideopcode = true;
		insn.opcode = getbyte();
	} else {
		insn.wideopcode = false;
	}
	decode_insn(&java_insns[insn.opcode]);

	if (insn.invalid) {
		insn.name = "db";
		insn.size = 1;
		insn.op[0].type = JAVA_OPTYPE_IMM;
		insn.op[0].size = 1;
		insn.op[0].imm = *code;
		for (int i=1; i < JAVAINSN_MAX_PARAM_COUNT; i++) insn.op[i].type=JAVA_OPTYPE_EMPTY;
	} else {
		insn.size = codep-ocodep;
	}
	return &insn;
}

void javadis::decode_insn(javaopc_insn *xinsn)
{
	if (!xinsn->name) {
		invalidate();
		return;
	}
	insn.name = xinsn->name;
	for (int i=0; i<JAVAINSN_MAX_PARAM_COUNT; i++) {
		decode_op(xinsn->optype[i], insn.wideopcode, &insn.op[i]);
	}
}

void javadis::decode_op(int optype, bool wideopc, java_insn_op *op)
{
	bool widesize = wideopc || (JOPC_SIZE(optype) == JOPC_SIZE_WIDE);
	switch (JOPC_TYPE(optype)) {
	case JOPC_TYPE_BYTE:
		op->type = JAVA_OPTYPE_IMM;
		op->size = 1;
		op->imm = getbyte();
		break;
	case JOPC_TYPE_CHAR:
		op->type = JAVA_OPTYPE_IMM;
		op->size = 1;
		op->imm = sint8(getbyte());
		break;
	case JOPC_TYPE_SHORT:
		op->type = JAVA_OPTYPE_IMM;
		op->size = 2;
		op->imm = sint16(getword());
		break;
	case JOPC_TYPE_SIMM:
		op->type = JAVA_OPTYPE_IMM;
		if (widesize) {
			op->size = 2;
			op->imm = sint16(getword());
		} else {
			op->size = 1;
			op->imm = sint8(getbyte());
		}
		break;
	case JOPC_TYPE_CONST:
		op->type = JAVA_OPTYPE_CONST;
		if (widesize) {
			op->size = 2;
			op->imm = getword();
		} else {
			op->size = 1;
			op->imm = getbyte();
		}
		break;
	case JOPC_TYPE_LOCAL:
		op->type = JAVA_OPTYPE_IMM;
		if (widesize) {
			op->size = 2;
			op->imm = getword();
		} else {
			op->size = 1;
			op->imm = getbyte();
		}
		break;
	case JOPC_TYPE_LABEL:
		op->type = JAVA_OPTYPE_LABEL;
		if (widesize) {
			op->size = 4;
			op->label = addr - 2;
			op->label += sint32(getdword());
		} else {
			op->size = 2;
			op->label = addr - 1;
			op->label += sint16(getword());
		}
		break;
	case JOPC_TYPE_ATYPE:
		op->type = JAVA_OPTYPE_ATYPE;
		op->size = 1;
		op->imm = getbyte();
		break;
	default:
		op->type = JAVA_OPTYPE_EMPTY;
	}
}

dis_insn *javadis::duplicateInsn(dis_insn *disasm_insn)
{
	javadis_insn *insn = ht_malloc(sizeof (javadis_insn));
	*insn = *(javadis_insn *)disasm_insn;
	return insn;
}

byte javadis::getbyte()
{
	if (codep-ocodep+1<=maxlen) {
		addr++;
		return *(codep++);
	} else {
		invalidate();
		return 0;
	}
}

uint16 javadis::getword()
{
	if (codep-ocodep+2<=maxlen) {
		uint16 w;
		addr += 2;
		w = codep[1] | (codep[0]<<8);
		codep += 2;
		return w;
	} else {
		invalidate();
		return 0;
	}
}

uint32 javadis::getdword()
{
	if (codep-ocodep+4<=maxlen) {
		uint32 w;
		addr += 4;
		w = codep[3] | (codep[2]<<8) | (codep[1]<<16) | (codep[0]<<24);
		codep += 4;
		return w;
	} else {
		invalidate();
		return 0;
	}
}

void javadis::getOpcodeMetrics(int &min_length, int &max_length, int &min_look_ahead, int &avg_look_ahead, int &addr_align)
{
	min_length = 1;
	max_length = 6;
	min_look_ahead = 120;
	avg_look_ahead = 24;
	addr_align = 1;
}

const char *javadis::getName()
{
	return "Java/Disassembler";
}

byte javadis::getSize(dis_insn *disasm_insn)
{
	return ((javadis_insn*)disasm_insn)->size;
}

void javadis::invalidate()
{
	insn.invalid = true;
}

ObjectID javadis::getObjectID() const
{
	return ATOM_DISASM_JAVA;
}

void javadis::str_op(char *opstr, int *opstrlen, javadis_insn *insn, java_insn_op *op)
{
	const char *cs_default = get_cs(e_cs_default);
	const char *cs_number = get_cs(e_cs_number);
//	const char *cs_symbol = get_cs(e_cs_symbol);
	const char *cs_comment = get_cs(e_cs_comment);

	char *opstrold = opstr;
	switch (op->type) {
	case JAVA_OPTYPE_CONST: {
		strcpy(opstr, cs_comment); opstr += strlen(cs_comment);
		opstr += token_func(opstr, 1024, op->imm, context);
		*opstr++ = ' ';
		strcpy(opstr, cs_number); opstr += strlen(cs_number);
		switch (op->size) {
		case 1:
			hexd(&opstr, 2, options, op->imm);
			break;
		case 2:
			hexd(&opstr, 4, options, op->imm);
			break;
		case 4:
			hexd(&opstr, 8, options, op->imm);
			break;
		}
		break;
	}
	case JAVA_OPTYPE_LABEL: {
		CPU_ADDR a;
		a.addr32.offset = op->imm;
		int slen;
		char *s = (addr_sym_func) ? addr_sym_func(a, &slen, addr_sym_func_context) : NULL;
		if (s) {
			memcpy(opstr, s, slen);
			opstr[slen]=0;
			opstr += slen;
		} else {
			strcpy(opstr, cs_number); opstr += strlen(cs_number);
			switch (op->size) {
			case 1:
				hexd(&opstr, 2, options, op->imm);
				break;
			case 2:
				hexd(&opstr, 4, options, op->imm);
				break;
			case 4:
				hexd(&opstr, 8, options, op->imm);
				break;
			}
			strcpy(opstr, cs_default); opstr += strlen(cs_default);
		}
		break;
	}
	case JAVA_OPTYPE_IMM: {
		CPU_ADDR a;
		a.addr32.offset=op->imm;
		strcpy(opstr, cs_number); opstr += strlen(cs_number);
		switch (op->size) {
		case 1:
			hexd(&opstr, 2, options, op->imm);
			break;
		case 2:
			hexd(&opstr, 4, options, op->imm);
			break;
		case 4:
			hexd(&opstr, 8, options, op->imm);
			break;
		}
		strcpy(opstr, cs_default); opstr += strlen(cs_default);
		break;
	}
	case JAVA_OPTYPE_ATYPE: {
		const char *atypes[] = {"boolean", "char", "float", "double", "byte", "short", "int", "long"};
		strcpy(opstr, cs_comment); opstr += strlen(cs_comment);
		if (op->imm >= 4 && op->imm <= 11) {
			*(opstr++) = '<'; 
			opstr += ht_strlcpy(opstr, atypes[op->imm - 4], 8);
			*(opstr++) = '>'; 
			*(opstr++) = 0; 
		} else {
			strcpy(opstr, "<?>");
		}
		break;
	}
	default:
		opstr[0]=0;
	}
	*opstrlen = opstr - opstrold;
}

void javadis::str_format(char **str, const char **format, const char *p, const char *n, char *op[3], int oplen[3], char stopchar, int print)
{	
	const char *cs_default = get_cs(e_cs_default);
	const char *cs_symbol = get_cs(e_cs_symbol);

	const char *f = *format;
	char *s = *str;
	while (*f) {
		if (*f == stopchar) break;
		switch (*f) {
		case '\t':
			if (print) do *s++ = ' '; while ((s-insnstr) % 16);
			break;
		case DISASM_STRF_VAR:
			f++;
			if (print) {
				const char *t = NULL;
				int tl = 0;
				switch (*f) {
				case DISASM_STRF_PREFIX:
					t=p;
					break;
				case DISASM_STRF_NAME:
					t=n;
					break;
				case DISASM_STRF_FIRST:
					t=op[0];
					tl=oplen[0];
					break;
				case DISASM_STRF_SECOND:
					t=op[1];
					tl=oplen[1];
					break;
				case DISASM_STRF_THIRD:
					t=op[2];
					tl=oplen[2];
					break;
				}
				if (tl) {
					memcpy(s, t, tl);
					s += tl;
					*s = 0;
				} else {
					strcpy(s, t);
					s += strlen(s);
				}
			}
			break;
		case DISASM_STRF_COND: {
			const char *t = NULL;
			f++;
			switch (*f) {
			case DISASM_STRF_PREFIX:
				t=p;
				break;
			case DISASM_STRF_NAME:
				t=n;
				break;
			case DISASM_STRF_FIRST:
				t=op[0];
				break;
			case DISASM_STRF_SECOND:
				t=op[1];
				break;
			case DISASM_STRF_THIRD:
				t=op[2];
				break;
			}
			f += 2;
			str_format(&s, &f, p, n, op, oplen, *(f-1), t && t[0]);
			break;
		}
		default:
			if (print) {
				bool x = (strchr(",.-=+-*/[]()", *f) != NULL) && *f;
				if (x) { strcpy(s, cs_symbol); s += strlen(cs_symbol); }
				*(s++) = *f;
				if (x) { strcpy(s, cs_default); s += strlen(cs_default); }
			}
		}
		f++;
	}
	*s = 0;
	*format = f;
	*str = s;
}

const char *javadis::str(dis_insn *disasm_insn, int options)
{
	return strf(disasm_insn, options, DISASM_STRF_DEFAULT_FORMAT);
}

const char *javadis::strf(dis_insn *disasm_insn, int opt, const char *format)
{
	javadis_insn *insn = (javadis_insn*)disasm_insn;
	char prefix[64];
	char *p = prefix;
	options = opt;
	*p = 0;

	char ops[3][512];	/* FIXME: possible buffer overflow ! */
	char *op[3];
	int oplen[3];

	if (options & DIS_STYLE_HIGHLIGHT) enable_highlighting();
	for (int i=0; i < JAVAINSN_MAX_PARAM_COUNT; i++) {
		op[i] = ops[i];
		str_op(op[i], &oplen[i], insn, &insn->op[i]);
	}
	char *s = insnstr;
	str_format(&s, &format, prefix, insn->name, op, oplen, 0, 1);
	disable_highlighting();
	return insnstr;
}

bool javadis::validInsn(dis_insn *disasm_insn)
{
	return !((javadis_insn *)disasm_insn)->invalid;
}