Dmitry Kabak (userdimaPreliminary exception support implementation0ccfe0313 years agoHistory
691 lines · 16.0 KB · BrainfuckRawDownload
## Class loader.# class:		ref Class;	# class under translationpcode:		array of PCode;	# pointers to byte code of defined methodsTHISCLASS:	string;SUPERCLASS:	string; STRING(i: int): string{	pick cp := class.cps[i] {	Putf8 =>		return cp.utf8.utf8;	* =>		badpick("STRING");	}	return nil;} CLASSNAME(i: int): string{	pick cp := class.cps[i] {	Pci =>		return STRING(cp.ci.name_index);	* =>		badpick("CLASSNAME");	}	return nil;} u8(): big{	b1, b2: big; 	b1 = big u4() << 32;	b2 = big u4() & 16rffffffff;	return b1 | b2;} ## Bytecode verification.# verifyutf8index(index: int){	verifycpindex(nil, index, 1 << CON_Utf8);	if(STRING(index) == nil)		verifyerrormess("nil name or descriptor");} verifyclassindex(index: int){	verifycpindex(nil, index, 1 << CON_Class);	pick cp := class.cps[index] {	Pci =>		verifyutf8index(cp.ci.name_index);	* =>		badpick("verifyclassindex");	}} verifyfielddesc(name_index: int, sig_index: int){	sig: string;	ftype: int; 	verifyutf8index(name_index);	verifyutf8index(sig_index);	sig = STRING(sig_index);	ftype = sig[0];	sig = nextjavatype(sig);	if(ftype == 'V' || sig != nil)		verifyerrormess("field descriptor");} verifymethoddesc(name_index: int, sig_index: int){	name, sig: string;	rtype: int;	wargs: int; 	verifyutf8index(name_index);	name = STRING(name_index);	verifyutf8index(sig_index);	sig = STRING(sig_index); 	# check special <method> names	if(name[0] == '<') {		if(name == "<init>")			;		else if(name == "<clinit>") {			if(sig != "()V")				verifyerrormess("<clinit> signature");			return;		} else			verifyerrormess("<method> name");	} 	# check signature	if(sig[0] != '(')		verifyerrormess("method descriptor");	sig = sig[1:];	wargs = 0;	while(sig[0] != ')') {		wargs++;		if(sig[0] == 'J' || sig[0] == 'D')			wargs++;		sig = nextjavatype(sig);	}	sig = sig[1:];	rtype = sig[0];	sig = nextjavatype(sig);	if(wargs > 255 || sig != nil || (name[0] == '<' && rtype != 'V'))		verifyerrormess("method descriptor");} verifycpindexes(){	i: int;	nameindex, sigindex, natindex: int; 	for(i = 1; i < class.cp_count; i++) {		pick cp := class.cps[i] {		Pci =>			verifyutf8index(cp.ci.name_index);		Pfmiref =>			verifyclassindex(cp.fmiref.class_index);			natindex = cp.fmiref.name_type_index;			verifycpindex(nil, natindex, 1 << CON_NameAndType);			pick cpnat := class.cps[natindex] {			Pnat =>				nameindex = cpnat.nat.name_index;				sigindex = cpnat.nat.sig_index;			* =>				badpick("verifycpindexes (inner)");			}			if(int class.cts[i] == CON_Fieldref)				verifyfielddesc(nameindex, sigindex);			else				verifymethoddesc(nameindex, sigindex);		Pstring_index =>			verifycpindex(nil, cp.string_index, 1 << CON_Utf8);		Ptint =>			;		Pnat =>			# CON_NameAndType is verified through			# CON_Fieldref, CON_Methodref, CON_InterfaceMref			;		Putf8 =>			;		Ptvlong =>			i++;		Ptdouble =>			if(int class.cts[i] == CON_Double)	# else CON_Float				i++;		# since 49.0		Pmethodhandle =>			case cp.mh.ref_kind {			# TODO: implement all ref_kinds handling			* =>				verifyerrormess("bad method_handle ref_kind");			}		Pmethodtype =>			verifycpindex(nil, cp.mt.descriptor_index, 1 << CON_Utf8);		Pinvokedyn =>			# TODO: verify bs_method_attr_index field			verifycpindex(nil, cp.invokedyn.name_type_index, 1 << CON_NameAndType);		* =>			badpick("verifycpindexes (outer)");		}	}} CLASSMUTEX:	con ACC_FINAL|ACC_ABSTRACT; verifyclassflags(){	bad: int; 	if(class.access_flags & ACC_INTERFACE) {		if(SUPERCLASS != "java/lang/Object")			verifyerrormess("superclass");		# java bug: ACC_ABSTRACT should be set ???		# bad = (class.access_flags & ACC_ABSTRACT) != ACC_ABSTRACT;		bad = 0;		bad += (class.access_flags & ACC_FINAL) != 0;	} else {		bad = (class.access_flags & CLASSMUTEX) == CLASSMUTEX;	}	if(bad)		verifyerrormess("access_flags");} multippp(flag: int): int{	ret: int; 	case flag & (ACC_PUBLIC|ACC_PRIVATE|ACC_PROTECTED) {	0 or	ACC_PUBLIC or	ACC_PRIVATE or	ACC_PROTECTED =>		ret = 0;	* =>		ret = 1;	}	return ret;} IFACEFIELD:	con ACC_PUBLIC|ACC_STATIC|ACC_FINAL;_IFACEFIELD:	con ACC_PRIVATE|ACC_PROTECTED|ACC_VOLATILE|ACC_TRANSIENT;FIELDMUTEX:	con ACC_FINAL|ACC_VOLATILE;CVATTRTAGS:	con ((1<<CON_Integer)|(1<<CON_Long)|(1<<CON_Float)|(1<<CON_Double)|(1<<CON_String)); verifyfield(fp: ref Field){	bad, n: int;	c: int; 	verifyfielddesc(fp.name_index, fp.sig_index);	if(class.access_flags & ACC_INTERFACE) {		bad = (fp.access_flags & _IFACEFIELD) != 0;		bad += (fp.access_flags & IFACEFIELD) != IFACEFIELD;	} else {		bad = multippp(fp.access_flags);		bad += (fp.access_flags & FIELDMUTEX) == FIELDMUTEX;	}	if(bad)		verifyerrormess("access_flags"); 	# verify ConstantValue attribute	n = CVattrindex(fp);	if(n == 0)		return;	verifycpindex(nil, n, CVATTRTAGS);	c = STRING(fp.sig_index)[0];	pick cp := class.cps[n] {	Ptdouble =>		if(int class.cts[n] == CON_Float)			bad = (c != 'F');		else			bad = (c != 'D');	Ptvlong =>		bad = (c != 'J');	Ptint =>		case c {		'Z' or		'B' or		'C' or		'S' or		'I' =>			bad = 0;		* =>			bad = 1;		}	Pstring_index =>		bad = (c != 'L');	* =>		bad = 1;	}	if(bad)		verifyerrormess("ConstantValue attribute");} IFACEMETHOD:	con ACC_PUBLIC|ACC_ABSTRACT;_IFACEMETHOD:	con ACC_PRIVATE|ACC_PROTECTED|ACC_STATIC|ACC_FINAL|ACC_SYNCHRONIZED|ACC_NATIVE;_INITFLAGS:	con ACC_STATIC|ACC_FINAL|ACC_SYNCHRONIZED|ACC_NATIVE|ACC_ABSTRACT;# java bug: ACC_SYNCHRONIZED wrongly allowed with ACC_ABSTRACT ???#METHODMUTEX:	con ACC_PRIVATE|ACC_STATIC|ACC_FINAL|ACC_SYNCHRONIZED|ACC_NATIVE;METHODMUTEX:	con ACC_PRIVATE|ACC_STATIC|ACC_FINAL|ACC_NATIVE; verifymethod(mp: ref Method){	bad: int;	name: string; 	verifymethoddesc(mp.name_index, mp.sig_index);	name = STRING(mp.name_index);	if(name == "<clinit>")		return;	if(class.access_flags & ACC_INTERFACE) {		bad = (mp.access_flags & _IFACEMETHOD) != 0;		bad += (mp.access_flags & IFACEMETHOD) != IFACEMETHOD;	} else {		bad = multippp(mp.access_flags);		if(name == "<init>")			bad += (mp.access_flags & _INITFLAGS) != 0;		if(mp.access_flags & ACC_ABSTRACT)			bad += (mp.access_flags & METHODMUTEX) != 0;	}	if(bad)		verifyerrormess("access_flags");	#	# Code attribute verified during disassembly	# ignore Exceptions attribute for now	#} ## Parse a byte stream into a Class stucture.# byte2Class(text: array of byte){	i, j: int;	fp: ref Field;	mp: ref Method; 	uSet(text);	class = ref Class(0, 0, 0, nil, nil, 0, 0, 0, 0, nil, 0, nil, 0, nil, 0, nil); 	if(u4() != int 16rCAFEBABE)		verifyerrormess("magic"); 	class.min = u2();	class.maj = u2(); 	class.cp_count = u2();	class.cps = array [class.cp_count] of ref Const;	class.cts = array [class.cp_count] of { * => byte 0 }; 	for(i = 1; i < class.cp_count; i++) {		class.cts[i] = byte u1();		case int class.cts[i] {		CON_Class =>			cp := ref Const.Pci;			cp.ci = ref Const_ci;			cp.ci.name_index = u2();			class.cps[i] = cp;		CON_Fieldref or		CON_Methodref or		CON_InterfaceMref =>			cp := ref Const.Pfmiref;			cp.fmiref = ref Const_fmiref;			cp.fmiref.class_index = u2();			cp.fmiref.name_type_index = u2();			class.cps[i] = cp;		CON_String =>			cp := ref Const.Pstring_index;			cp.string_index = u2();			class.cps[i] = cp;		CON_Integer =>			cp := ref Const.Ptint;			cp.tint = u4();			class.cps[i] = cp;		CON_Float =>			cp := ref Const.Ptdouble;			cp.tdouble = math->bits32real(u4());			class.cps[i] = cp;		CON_Long =>			cp := ref Const.Ptvlong;			cp.tvlong = u8();			class.cps[i] = cp;			i++;		CON_Double =>			cp := ref Const.Ptdouble;			cp.tdouble = math->bits64real(u8());			class.cps[i] = cp;			i++;		CON_NameAndType =>			cp := ref Const.Pnat;			cp.nat = ref Const_nat;			cp.nat.name_index = u2();			cp.nat.sig_index = u2();			class.cps[i] = cp;		CON_Utf8 =>			cp := ref Const.Putf8;			cp.utf8 = ref Const_utf8;			cp.utf8.ln = u2();			# null char represented as 16rC080 in String literals			a := uPtr(cp.utf8.ln);			(src, dst) := (0, 0);			while(src < cp.utf8.ln) {				if(src+1 < cp.utf8.ln && a[src] == byte 16rC0				&& a[src+1] == byte 16r80) {					a[dst] = byte 0;					src++;				} else					a[dst] = a[src];				src++;				dst++;			}			cp.utf8.utf8 = string a[0:dst];			uN(cp.utf8.ln);			class.cps[i] = cp;		# since 49.0		CON_MethodHandle =>			verifyerrormess("MethodHandles are not implemented");			cp := ref Const.Pmethodhandle;			cp.mh = ref Const_methodhandle;			cp.mh.ref_kind = int u1();			cp.mh.ref_index = u2();			class.cps[i] = cp;		CON_MethodType =>			verifyerrormess("MethodTypes are not implemented");			cp := ref Const.Pmethodtype;			cp.mt = ref Const_methodtype;			cp.mt.descriptor_index = u2();			class.cps[i] = cp;		CON_InvokeDynamic =>			verifyerrormess("InvokeDynamics are not implemented");			cp := ref Const.Pinvokedyn;			cp.invokedyn = ref Const_invokedyn;			cp.invokedyn.bs_method_attr_index = u2();			cp.invokedyn.name_type_index = u2();			class.cps[i] = cp;		* =>			verifyerrormess("constant pool tag");		}	} 	verifycpindexes();		# verify after all are established 	class.access_flags = u2();	# verify after [THIS|SUPER]CLASS set 	class.this_class = u2();	verifyclassindex(class.this_class);	THISCLASS = CLASSNAME(class.this_class); 	class.super_class = u2();	if(class.super_class) {		verifyclassindex(class.super_class);		SUPERCLASS = CLASSNAME(class.super_class);	} else if(THISCLASS != "java/lang/Object")		verifyerrormess("superclass"); 	verifyclassflags(); 	# for compatibility with JavaSoft VM	if(len THISCLASS > len "inferno/vm/"	&& THISCLASS[0:len "inferno/vm/"] == "inferno/vm/") {		#		# ACC_ABSTRACT & ACC_FINAL are both set in JVM,		# but a class can't be declared that way		#		class.access_flags |= ACC_ABSTRACT;		#		# ACC_SUPER not set in JVM, but javac sets it		# for inferno/vm/Array		#		class.access_flags &= ~ACC_SUPER;	} else if(class.access_flags & ACC_INTERFACE) {		# interfaces are implicitly abstract		class.access_flags |= ACC_ABSTRACT;	} 	class.interfaces_count = u2();	if(class.interfaces_count > 0)		class.interfaces = array [class.interfaces_count] of int;	for(i = 0; i < class.interfaces_count; i++) {		class.interfaces[i] = u2();		verifyclassindex(class.interfaces[i]);	} 	class.fields_count = u2();	if(class.fields_count > 0)		class.fields = array [class.fields_count] of ref Field;	for(i = 0; i < class.fields_count; i++) {		class.fields[i] = ref Field(0, 0, 0, 0, nil);		fp = class.fields[i];		fp.access_flags = u2();		fp.name_index = u2();		fp.sig_index = u2();		fp.attr_count = u2();		if(fp.attr_count > 0)			fp.attr_info = array [fp.attr_count] of ref Attr;		for(j = 0; j < fp.attr_count; j++)			fp.attr_info[j] = getattr();		verifyfield(fp);	} 	class.methods_count = u2();	if(class.methods_count > 0) {		class.methods = array [class.methods_count] of ref Method;		pcode = array [class.methods_count] of PCode;	}	for(i = 0; i < class.methods_count; i++) {		class.methods[i] = ref Method(0, 0, 0, 0, nil);		mp = class.methods[i];		mp.access_flags = u2();		mp.name_index = u2();		mp.sig_index = u2();		mp.attr_count = u2();		if(mp.attr_count > 0)			mp.attr_info = array [mp.attr_count] of ref Attr;		for(j = 0; j < mp.attr_count; j++)			mp.attr_info[j] = getattr();		verifymethod(mp);	} 	# get SourceFile attribute	i = u2();	for(j = 0; j < i; j++) {		a := getattr();		if(STRING(a.name) == "SourceFile") {			class.source_file = (int a.info[0] << 8) | int a.info[1];			verifyutf8index(class.source_file);			break;		}

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