+/* code.c
+
+ Routines for handling Flash2 AVM2 ABC Actionscript
+
+ Extension module for the rfxswf library.
+ Part of the swftools package.
+
+ Copyright (c) 2008 Matthias Kramm <kramm@quiss.org>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
+
#include <assert.h>
#include "code.h"
+#include "pool.h"
#define OP_REGISTER 1
#define OP_STACK_ARGS 2
#define OP_SET_DXNS 8
#define OP_RETURN 16
#define OP_THROW 32
-#define OP_BRANCH 32
-#define OP_JUMP 64
-#define OP_LABEL 128
-#define OP_SWITCH 256
-#define OP_NEED_ACTIVATION 512
-#define OP_STACK_ARGS2 1024
+#define OP_BRANCH 64
+#define OP_JUMP 128
+#define OP_LABEL 256
+#define OP_LOOKUPSWITCH 512
+#define OP_NEED_ACTIVATION 1024
+#define OP_STACK_ARGS2 2048
+#define OP_INTERNAL 32768
/* 2 = u30 index into multiname
m = u30 index into method
n = u30 number of params
i = u30 index into method info
b = byte
- s = short
c = u30 index into class
+ N = u30 index into namespaces
s = string (u30 index into strings)
S = switch
u = u30
r = register
*/
+
opcode_t opcodes[]={
{0xa0, "add", "", -2, 1, 0, 0},
{0xc5, "add_i", "", -2, 1, 0, 0},
{0x86, "astype", "2", -1, 1, 0, 0},
{0x87, "astypelate", "", -2, 1, 0, 0},
{0xA8, "bitand", "", -2, 1, 0, 0},
-{0x97, "bitnot", "" -1, 1, 0, 0},
+{0x97, "bitnot", "", -1, 1, 0, 0},
{0xa9, "bitor", "", -2, 1, 0, 0},
-{0xaa, "bitxor", "" -2, 1, 0, 0},
+{0xaa, "bitxor", "", -2, 1, 0, 0},
{0x41, "call", "n", -2, 1, 0, OP_STACK_ARGS},
-{0x43, "callmethod", "mn", -1, 1, 0, OP_STACK_ARGS|OP_STACK_NS},
+{0x43, "callmethod", "mn", -1, 1, 0, OP_STACK_ARGS},
{0x4c, "callproplex", "2n", -1, 1, 0, OP_STACK_ARGS|OP_STACK_NS},
{0x46, "callproperty", "2n", -1, 1, 0, OP_STACK_ARGS|OP_STACK_NS},
{0x4f, "callpropvoid", "2n", -1, 0, 0, OP_STACK_ARGS|OP_STACK_NS},
{0x85, "coerce_s", "", -1, 1, 0, 0},
{0x42, "construct", "n", -1, 1, 0, OP_STACK_ARGS},
{0x4a, "constructprop", "2n", -1, 1, 0, OP_STACK_ARGS|OP_STACK_NS},
-{0x49, "constructsuper", "n", -1, 1, 0, OP_STACK_ARGS},
+{0x49, "constructsuper", "n", -1, 0, 0, OP_STACK_ARGS},
{0x76, "convert_b", "", -1, 1, 0, 0},
{0x73, "convert_i", "", -1, 1, 0, 0},
{0x75, "convert_d", "", -1, 1, 0, 0},
{0x65, "getscopeobject", "u", 0, 1, 0, 0}, // u = index into scope stack
{0x6c, "getslot", "u", -1, 1, 0, 0},
{0x04, "getsuper", "2", -1, 1, 0, OP_STACK_NS},
-{0xaf, "greaterequals", "", -2, 1, 0, 0},
+{0xaf, "greaterthan", "", -2, 1, 0, 0},
+{0xb0, "greaterequals", "", -2, 1, 0, 0},
{0x1f, "hasnext", "", -2, 1, 0, 0},
{0x32, "hasnext2", "rr", 0, 1, 0, OP_REGISTER},
{0x13, "ifeq", "j", -2, 0, 0, OP_BRANCH},
{0x12, "iffalse", "j", -1, 0, 0, OP_BRANCH},
{0x18, "ifge", "j", -2, 0, 0, OP_BRANCH},
{0x17, "ifgt", "j", -2, 0, 0, OP_BRANCH},
-{0x16, "ifle", "j" -2, 0, 0, OP_BRANCH},
+{0x16, "ifle", "j", -2, 0, 0, OP_BRANCH},
{0x15, "iflt", "j", -2, 0, 0, OP_BRANCH},
{0x0f, "ifnge", "j", -2, 0, 0, OP_BRANCH},
{0x0e, "ifngt", "j", -2, 0, 0, OP_BRANCH},
{0xc2, "inclocal_i", "r", 0, 0, 0, OP_REGISTER},
{0x91, "increment", "", -1, 1, 0, 0},
{0xc0, "increment_i", "", -1, 1, 0, 0},
-{0x68, "initproperty", "2", -1, 0, 0, OP_STACK_NS},
+{0x68, "initproperty", "2", -2, 0, 0, OP_STACK_NS},
{0xb1, "instanceof", "", -2, 1, 0, 0},
{0xb2, "istype", "2", -1, 1, 0, 0}, // may not be a runtime multiname
{0xb3, "istypelate", "", -2, 1, 0, 0},
{0x10, "jump", "j", 0, 0, 0, OP_JUMP},
{0x08, "kill", "r", 0, 0, 0, OP_REGISTER},
{0x09, "label", "", 0, 0, 0, OP_LABEL},
-{0xae, "lessequals", "", -2, 1, 0, OP_BRANCH},
-{0xad, "lessthan", "", -2, 1, 0, OP_BRANCH},
-{0x1b, "lookupswitch", "S", -1, 0, 0, OP_SWITCH},
+{0xae, "lessequals", "", -2, 1, 0, 0},
+{0xad, "lessthan", "", -2, 1, 0, 0},
+{0x1b, "lookupswitch", "S", -1, 0, 0, OP_LOOKUPSWITCH},
{0xa5, "lshift", "", -2, 1, 0, 0},
{0xa4, "modulo", "", -2, 1, 0, 0},
{0xa2, "multiply", "", -2, 1, 0, 0},
{0x90, "negate", "", -1, 1, 0, 0},
{0xc4, "negate_i", "", -1, 1, 0, 0},
{0x57, "newactivation", "", 0, 1, 0, OP_NEED_ACTIVATION},
-{0x56, "newarray", "u", 0, 1, 0, OP_STACK_ARGS},
+{0x56, "newarray", "n", 0, 1, 0, OP_STACK_ARGS},
{0x5a, "newcatch", "u", 0, 1, 0, 0}, //u = index into exception_info
{0x58, "newclass", "c", -1, 1, 0, 0}, //c = index into class_info
{0x40, "newfunction", "m", 0, 1, 0, 0}, //i = index into method_info
-{0x55, "newobject", "u", 0, 1, 0, OP_STACK_ARGS2},
+{0x55, "newobject", "n", 0, 1, 0, OP_STACK_ARGS2},
{0x1e, "nextname", "", -2, 1, 0, 0},
{0x23, "nextvalue", "", -2, 1, 0, 0},
{0x02, "nop", "", 0, 0, 0, 0},
{0x29, "pop", "", -1, 0, 0, 0},
{0x1d, "popscope", "", 0, 0,-1, 0},
{0x24, "pushbyte", "b", 0, 1, 0, 0},
-{0x2f, "pushdouble", "u", 0, 1, 0, 0}, //index into floats
+{0x2f, "pushdouble", "f", 0, 1, 0, 0}, //index into floats
{0x27, "pushfalse", "", 0, 1, 0, 0},
-{0x2d, "pushint", "u", 0, 1, 0, 0}, //index into ints
-{0x31, "pushnamespace", "u", 0, 1, 0, 0}, //index into namespace
+{0x2d, "pushint", "I", 0, 1, 0, 0}, //index into ints
+{0x31, "pushnamespace", "N", 0, 1, 0, 0}, //index into namespace
{0x28, "pushnan", "", 0, 1, 0, 0},
{0x20, "pushnull", "", 0, 1, 0, 0},
-{0x30, "pushscope", "", 0, 0, 1, 0},
+{0x30, "pushscope", "", -1, 0, 1, 0},
{0x25, "pushshort", "u", 0, 1, 0, 0},
{0x2c, "pushstring", "s", 0, 1, 0, 0},
{0x26, "pushtrue", "", 0, 1, 0, 0},
-{0x2e, "pushuint", "u", 0, 1, 0, 0}, //index into uints
+{0x2e, "pushuint", "U", 0, 1, 0, 0}, //index into uints
{0x21, "pushundefined", "", 0, 1, 0, 0},
{0x1c, "pushwith", "", -1, 0, 1, 0},
{0x48, "returnvalue", "", -1, 0, 0, OP_RETURN},
{0xd7, "setlocal_3", "", -1, 0, 0, OP_REGISTER},
{0x6f, "setglobalslot", "u", -1, 0, 0, 0},
{0x61, "setproperty", "2", -2, 0, 0, OP_STACK_NS},
-{0x6d, "setslot", "2", -2, 0, 0, 0},
+{0x6d, "setslot", "u", -2, 0, 0, 0},
{0x05, "setsuper", "2", -2, 0, 0, OP_STACK_NS},
{0xac, "strictequals", "", -2, 1, 0, 0},
{0xa1, "subtract", "", -2, 1, 0, 0},
{0x03, "throw", "", -1, 0, 0, OP_THROW},
{0x95, "typeof", "", -1, 1, 0, 0},
{0xa7, "urshift", "", -2, 1, 0, 0},
-{0xb0, "xxx", "", 0, 0, 0, 0},
+
+/* opcodes not documented, but seen in the wild */
+{0x53, "applytype", "n", -1, 1, 0, OP_STACK_ARGS}, //seen in builtin.abc
+
+/* dummy instructions. Warning: these are not actually supported by flash */
+{0xfb, "__pushpackage__", "s", 0, 1, 0, OP_INTERNAL},
+{0xfc, "__rethrow__", "", 0, 0, 0, OP_THROW|OP_INTERNAL},
+{0xfd, "__fallthrough__", "s", 0, 0, 0, OP_INTERNAL},
+{0xfe, "__continue__", "s", 0, 0, 0, OP_RETURN|OP_INTERNAL},
+{0xff, "__break__", "s", 0, 0, 0, OP_RETURN|OP_INTERNAL},
};
-static U8 op2index[256] = {254};
+static opcode_t* op2op[256] = {0,0,0};
-opcode_t* opcode_get(U8 op)
+static inline opcode_t* opcode_get(U8 op)
{
int t;
- if(op2index[0]==254) {
- memset(op2index, 255, sizeof(op2index));
+ if(!op2op[0x02]) {
+ memset(op2op, 0, sizeof(op2op));
for(t=0;t<sizeof(opcodes)/sizeof(opcodes[0]);t++) {
- op2index[opcodes[t].opcode] = t;
+ op2op[opcodes[t].opcode] = &opcodes[t];
}
}
- if(op2index[op]!=255)
- return &opcodes[op2index[op]];
- return 0;
+ return op2op[op];
}
-abc_code_t*code_parse(TAG*tag, int len, abc_file_t*file, pool_t*pool)
+static code_t*pos2code(code_t**bytepos, code_t*c, int pos, int len)
+{
+ if(c) {
+ pos+=c->pos;
+ }
+ if(pos < 0 ||
+ pos > len ||
+ (pos!=len && !bytepos[pos])) {
+ /* flex likes to generate these. yuck. */
+ if(c) {
+ opcode_t*op = opcode_get(c->opcode);
+ fprintf(stderr, "Warning: Invalid jump instruction \"%s\" from %d to %d (%d)\n", op->name, c->pos, pos, len);
+ } else {
+ fprintf(stderr, "Warning: Invalid jump to %d (%d)\n", pos, len);
+ }
+ return 0;
+ } else {
+ if(pos==len) {
+ //opcode_t*op = opcode_get(c->opcode);
+ //fprintf(stderr, "Warning: jump beyond end of code in instruction %s at position %d\n", op->name, c->pos);
+ return 0;
+ } else {
+ return bytepos[pos];
+ }
+ }
+}
+code_t* code_atposition(codelookup_t*l, int pos)
{
- abc_code_t*head=0;
- abc_code_t*code=0;
+ return pos2code(l->bytepos, 0, pos, l->len);
+}
+
+void lookupswitch_print(lookupswitch_t*l)
+{
+ printf("default: %08x\n", (int)l->def);
+ code_list_t*t = l->targets;
+ while(t) {
+ printf("target: %08x\n", (int)t->code);
+ t = t->next;
+ }
+}
+
+code_t*code_parse(TAG*tag, int len, abc_file_t*file, pool_t*pool, codelookup_t**codelookup)
+{
+ code_t*head=0;
+ code_t*code=0;
+ int start=tag->pos;
int end=tag->pos+len;
//printf("-->\n");fflush(stdout);
+
+ code_t**bytepos = rfx_calloc(sizeof(code_t*)*len);
+
while(tag->pos<end) {
+ int codepos = tag->pos-start;
U8 opcode = swf_GetU8(tag);
opcode_t*op = opcode_get(opcode);
if(!op) {
fprintf(stderr, "Can't parse opcode %02x\n", opcode);
- return head;
+ continue;
}
//printf("%s\n", op->name);fflush(stdout);
- NEW(abc_code_t,c);
+ NEW(code_t,c);
+ c->pos = codepos;
+
+ bytepos[codepos] = c;
+
if(!head) {
head = code = c;
} else {
code->next = c;
+ c->prev = code;
code = c;
}
data = (void*)(ptroff_t)swf_GetU30(tag);
} else if(*p == '2') { //multiname
data = multiname_clone(pool_lookup_multiname(pool, swf_GetU30(tag)));
+ } else if(*p == 'N') { //namespace
+ data = namespace_clone(pool_lookup_namespace(pool, swf_GetU30(tag)));
+ } else if(*p == 'U') { //uint
+ data = (void*)(ptroff_t)pool_lookup_uint(pool, swf_GetU30(tag));
+ } else if(*p == 'I') { //int
+ data = (void*)(ptroff_t)pool_lookup_int(pool, swf_GetU30(tag));
+ } else if(*p == 'f') { //int
+ double*fp = malloc(sizeof(double));
+ *fp = pool_lookup_float(pool, swf_GetU30(tag));
+ data = fp;
} else if(*p == 'm') { //method
data = array_getvalue(file->methods, swf_GetU30(tag));
} else if(*p == 'c') { //classinfo
data = (void*)(ptroff_t)swf_GetU30(tag);
} else if(*p == 'b') { // byte
data = (void*)(ptroff_t)swf_GetU8(tag);
- } else if(*p == 'j') { // jump TODO
- data = (void*)(ptroff_t)swf_GetS24(tag);
+ } else if(*p == 'j') { // jump
+ int j = swf_GetS24(tag);
+ data = (void*)(ptroff_t)j;
} else if(*p == 's') { // string
- data = strdup((char*)pool_lookup_string(pool, swf_GetU30(tag)));
+ string_t s = pool_lookup_string2(pool, swf_GetU30(tag));
+ data = string_dup3(&s);
} else if(*p == 'D') { // debug
/*type, usually 1*/
U8 type = swf_GetU8(tag);
if(type!=1)
fprintf(stderr, "Unknown debug type: %02x\n", type);
/*register name*/
- code->params[0] = strdup((char*)pool_lookup_string(pool, swf_GetU30(tag)));
+ code->data[0] = strdup((char*)pool_lookup_string(pool, swf_GetU30(tag)));
/*register index*/
- code->params[1] = (void*)(ptroff_t)swf_GetU8(tag);
+ code->data[1] = (void*)(ptroff_t)swf_GetU8(tag);
/*unused*/
swf_GetU30(tag);
- } else if(*p == 'S') { // switch statement TODO
- /* I hate these things */
- swf_GetU24(tag); //default
+ } else if(*p == 'S') { // switch statement
+ lookupswitch_t*l = malloc(sizeof(lookupswitch_t));
+ l->def = (code_t*)(ptroff_t)swf_GetS24(tag);
+ l->targets = list_new();
int num = swf_GetU30(tag)+1;
int t;
for(t=0;t<num;t++)
- swf_GetU24(tag);
- data = 0;
+ list_append(l->targets, (code_t*)(ptroff_t)swf_GetS24(tag));
+ data = l;
} else {
- printf("Can't parse opcode param type \"%c\"\n", *p);
+ printf("Can't parse opcode param type \"%c\" (for op %02x %s).\n", *p, code->opcode, op->name);
return 0;
}
if(data)
- code->params[pos++] = data;
+ code->data[pos++] = data;
p++;
}
}
+
+//#define DEBUG_BYTES
+#ifdef DEBUG_BYTES
+ int t;
+ for(t=0;t<len;t++) {
+ code_t*c = bytepos[t];
+ if(c) {
+ opcode_t*op = opcode_get(c->opcode);
+ if(op->flags & (OP_JUMP|OP_BRANCH)) {
+ printf("%50d) %02x %s %d\n", t, tag->data[start+t], op->name, c->data[0]);
+ } else {
+ printf("%50d) %02x %s\n", t, tag->data[start+t], op->name);
+ }
+ } else {
+ printf("%50d) %02x\n", t, tag->data[start+t]);
+ }
+ }
+ //printf("%05d) %02x\n", t, tag->data[start+t]);
+#endif
+
+ code_t*c = head;
+ while(c) {
+ opcode_t*op = opcode_get(c->opcode);
+ if(op->flags & (OP_JUMP|OP_BRANCH)) {
+ int j = ((int)(ptroff_t)c->data[0]);
+ c->branch = pos2code(bytepos,c,j+4,len);
+ } else if(op->flags & (OP_LOOKUPSWITCH)) {
+ lookupswitch_t*l = (lookupswitch_t*)c->data[0];
+ int offset = 0;
+ l->def = pos2code(bytepos,c,(ptroff_t)l->def+offset,len);
+ code_list_t*t=l->targets;
+ while(t) {
+ t->code = pos2code(bytepos,c,(ptroff_t)t->code+offset,len);
+ t = t->next;
+ }
+ }
+ c = c->next;
+ }
+
+ if(codelookup) {
+ (*codelookup) = malloc(sizeof(codelookup_t));
+ (*codelookup)->bytepos = bytepos;
+ (*codelookup)->len = len;
+ } else {
+ free(bytepos);
+ }
+
return head;
}
-void code_free(abc_code_t*c)
+void codelookup_free(codelookup_t*codelookup)
{
+ free(codelookup->bytepos);codelookup->bytepos=0;
+ free(codelookup);
+}
+
+void code_free(code_t*c)
+{
+ c = code_start(c);
while(c) {
- abc_code_t*next = c->next;
+ code_t*next = c->next;
opcode_t*op = opcode_get(c->opcode);
char*p = op?op->params:"";
int pos=0;
while(*p) {
- void*data = c->params[pos];
+ void*data = c->data[pos];
if(*p == '2') { //multiname
multiname_destroy(data);
- } else if(strchr("sD", *p)) {
+ } else if(*p == 'N') { //namespace
+ namespace_destroy(data);
+ } else if(strchr("sDf", *p)) {
free(data);
+ } else if(strchr("S", *p)) {
+ lookupswitch_t*l = (lookupswitch_t*)data;
+ list_free(l->targets);l->targets=0;
+ free(l);
}
- c->params[pos]=0;
+ c->data[pos]=0;
p++;pos++;
}
memset(c, 0, sizeof(c));
}
}
-int code_dump(abc_code_t*c, abc_file_t*file, char*prefix, FILE*fo)
+static int opcode_write(TAG*tag, code_t*c, pool_t*pool, abc_file_t*file, int length)
{
- pool_t*pool = pool_new();
+ opcode_t*op = opcode_get(c->opcode);
+ char*p = op->params;
+ int pos = 0;
+ int len = 0;
+
+ if(tag)
+ swf_SetU8(tag, c->opcode);
+ len++;
+
+ if(op->flags & OP_INTERNAL) {
+ if(c->opcode == OPCODE___BREAK__ ||
+ c->opcode == OPCODE___CONTINUE__) {
+ fprintf(stderr, "Unresolved %s\n", op->name);
+ } else {
+ fprintf(stderr, "Error: writing undefined internal opcode %s\n", op->name);
+ }
+ }
+
+ while(*p) {
+ void*data = c->data[pos++];
+ assert(pos<=2);
+ switch(*p) {
+ case 'n': { // number
+ len += swf_SetU30(tag, (ptroff_t)data);
+ break;
+ }
+ case '2': { //multiname
+ multiname_t*m = (multiname_t*)data;
+ len += swf_SetU30(tag, pool_register_multiname(pool, m));
+ break;
+ }
+ case 'N': { //namespace
+ namespace_t*ns = (namespace_t*)data;
+ len += swf_SetU30(tag, pool_register_namespace(pool, ns));
+ break;
+ }
+ case 'm': { //method
+ abc_method_t*m = (abc_method_t*)data;
+ len += swf_SetU30(tag, m->index);
+ break;
+ }
+ case 'c': { //classinfo
+ abc_class_t*cls = (abc_class_t*)data;
+ len += swf_SetU30(tag, cls->index);
+ break;
+ }
+ case 'i': { //methodbody
+ abc_method_body_t*m = (abc_method_body_t*)data;
+ len += swf_SetU30(tag, m->index);
+ break;
+ }
+ case 'I': { // int
+ len += swf_SetU30(tag, pool_register_int(pool, (ptroff_t)data));
+ break;
+ }
+ case 'U': { // uint
+ len += swf_SetU30(tag, pool_register_uint(pool, (ptroff_t)data));
+ break;
+ }
+ case 'f': { // float
+ len += swf_SetU30(tag, pool_register_float(pool, *(double*)data));
+ break;
+ }
+ case 'u': { // integer
+ len += swf_SetU30(tag, (ptroff_t)data);
+ break;
+ }
+ case 'r': { // integer
+ len += swf_SetU30(tag, (ptroff_t)data);
+ break;
+ }
+ case 'b': { // byte
+ if(tag)
+ swf_SetU8(tag, (ptroff_t)data);
+ len++;
+ break;
+ }
+ case 'j': { // jump
+ int skip = length-c->pos-4;
+ if(c->branch)
+ skip = (c->branch->pos) - c->pos - 4;
+ len += swf_SetS24(tag, skip);
+ break;
+ }
+ case 's': { // string
+ int index = pool_register_string2(pool, (string_t*)data);
+ len += swf_SetU30(tag, index);
+ break;
+ }
+ case 'D': { // debug statement
+ if(tag)
+ swf_SetU8(tag, 1);
+ len++;
+ len+=swf_SetU30(tag, pool_register_string(pool,c->data[0]));
+ if(tag)
+ swf_SetU8(tag, (ptroff_t)c->data[1]);
+ len++;
+ len+=swf_SetU30(tag, 0);
+ break;
+ }
+ case 'S': { // switch statement
+ lookupswitch_t*l = (lookupswitch_t*)data;
+ int offset = 0;
+ len+=swf_SetS24(tag, l->def->pos-c->pos+offset); //default
+ code_list_t*t = l->targets;
+ if(list_length(t)) {
+ len+=swf_SetU30(tag, list_length(t)-1); //nr-1
+ code_list_t*t = l->targets;
+ while(t) {
+ len+=swf_SetS24(tag, t->code->pos - c->pos+offset);
+ t = t->next;
+ }
+ } else {
+ len+=swf_SetU30(tag, 0); //nr-1
+ len+=swf_SetS24(tag, l->def->pos-c->pos+offset);
+ }
+ break;
+ }
+ default:
+ printf("Can't parse opcode param type \"%c\"\n", *p);
+ }
+ p++;
+ }
+ return len;
+}
+void code_write(TAG*tag, code_t*code, pool_t*pool, abc_file_t*file)
+{
+ code = code_start(code);
+ int pos = 0;
+ int length = 0;
+ code_t*c = code;
+ while(c) {
+ c->pos = pos;
+ pos += opcode_write(0, c, pool, file, 0);
+ c = c->next;
+ }
+ length = pos;
+ swf_SetU30(tag, pos);
+ int start = tag->len;
+ c = code;
+ pos = 0;
+ while(c) {
+ opcode_t*op = opcode_get(code->opcode);
+ if(op->flags&(OP_BRANCH|OP_JUMP)) {
+ int skip = 0;
+ }
+ pos += opcode_write(tag, c, pool, file, length);
+ c = c->next;
+ }
+ assert(tag->len - start == pos);
+}
+
+typedef struct {
+ int stackpos;
+ int scopepos;
+ code_t*code;
+ char flags;
+ char error;
+} stackpos_t;
+
+typedef struct {
+ stackpos_t*stack;
+ int num;
+ int maxlocal;
+ int maxstack;
+ int maxscope;
+ int flags;
+} currentstats_t;
+
+static int stack_minus(code_t*c)
+{
+ opcode_t*op = opcode_get(c->opcode);
+ if(op->stack_minus>0) {
+ fprintf(stderr, "Invalid opcode entry %02x %s\n", c->opcode, op->name);
+ }
+ int stack = op->stack_minus;
+ if(op->flags&OP_STACK_NS) {
+ multiname_t*m = (multiname_t*)c->data[0];
+ if(multiname_late_namespace(m))
+ stack--;
+ if(multiname_late_name(m))
+ stack--;
+ }
+ if(op->flags&OP_STACK_ARGS || op->flags&OP_STACK_ARGS2) {
+ assert(strchr(op->params, 'n'));
+ int nr = (ptroff_t)(op->params[0]=='n'?c->data[0]:c->data[1]);
+ stack-=nr;
+ if(op->flags&OP_STACK_ARGS2)
+ stack-=nr;
+ }
+ return stack;
+}
+static void handleregister(currentstats_t*stats, int reg)
+{
+ if(reg+1 > stats->maxlocal)
+ stats->maxlocal = reg+1;
+}
+
+#define FLAG_SEEN 1
+#define FLAG_ERROR 2
+
+static void dumpstack(currentstats_t*stats)
+{
+ int t;
+ for(t=0;t<stats->num;t++) {
+ code_t*c = stats->stack[t].code;
+ opcode_t*op = opcode_get(c->opcode);
+ printf("%05d) %c %d:%d %s", t, (stats->stack[t].flags&FLAG_SEEN)?'x':'|',
+ stats->stack[t].stackpos,
+ stats->stack[t].scopepos,
+ op->name);
+
+ if(op->flags&(OP_BRANCH|OP_JUMP)) {
+ if(c->branch)
+ printf(" ->%d\n", c->branch->pos);
+ else
+ printf(" 00000000\n");
+ }
+ if(op->params[0]=='2') {
+ printf(" %s", multiname_tostring(c->data[0]));
+ } else if(op->params[0]=='N') {
+ printf(" %s", namespace_tostring(c->data[0]));
+ }
+ printf("\n");
+ }
+}
+
+static char callcode(currentstats_t*stats, int pos, int stack, int scope)
+{
+ while(pos<stats->num) {
+ if(stats->stack[pos].flags&FLAG_SEEN) {
+ if(stats->stack[pos].stackpos != stack ||
+ stats->stack[pos].scopepos != scope) {
+ //dumpstack(stats);
+ stats->stack[pos].flags |= FLAG_ERROR;
+ fprintf(stderr, "Stack mismatch at pos %d\n", pos);
+ fprintf(stderr, "Should be: %d:%d, is: %d:%d\n", stack, scope,
+ stats->stack[pos].stackpos, stats->stack[pos].scopepos);
+
+ /* return error here if we do verification */
+ //return 0;
+ }
+ return 1;
+ }
+
+ stats->stack[pos].flags |= FLAG_SEEN;
+ stats->stack[pos].stackpos = stack;
+ stats->stack[pos].scopepos = scope;
+
+ code_t*c = stats->stack[pos].code;
+ opcode_t*op = opcode_get(c->opcode);
+
+ //printf("Walking %s at position %d, stack=%d, scope=%d\n", op->name, pos, stack, scope);
+
+ stack += stack_minus(c);
+
+ if(stack<0) {
+ stats->stack[pos].flags |= FLAG_ERROR;
+ fprintf(stderr, "error: stack underflow at %d (%s)\n", pos, op->name);
+
+ /* if we would do true verification (if we would be a vm), this is
+ where we would return the error
+ return 0;
+ */
+ }
+
+ stack += op->stack_plus;
+ scope += op->scope_stack_plus;
+
+ if(stack > stats->maxstack)
+ stats->maxstack = stack;
+ if(scope > stats->maxscope)
+ stats->maxscope = scope;
+
+ if(op->flags & OP_SET_DXNS)
+ stats->flags |= FLAGS_SET_DXNS;
+ if(op->flags & OP_NEED_ACTIVATION)
+ stats->flags |= FLAGS_ACTIVATION;
+
+ if(c->opcode == OPCODE_NEWCLASS) {
+ abc_class_t*cls = (abc_class_t*)(c->data[0]);
+ if(scope > cls->init_scope_depth)
+ cls->init_scope_depth = scope;
+ }
+ if(c->opcode == OPCODE_NEWFUNCTION) {
+ abc_method_t*m = (abc_method_t*)(c->data[0]);
+ if(m->body && scope > m->body->init_scope_depth)
+ m->body->init_scope_depth = scope;
+ }
+
+ if(op->flags & OP_REGISTER) {
+ char*p = op->params;
+ int pos = 0;
+ char ok=0;
+ while(*p) {
+ if(*p=='r') {
+ handleregister(stats, (ptroff_t)c->data[pos]);
+ ok = 1;
+ }
+ p++;
+ }
+ if(!ok) {
+ handleregister(stats, c->opcode&3);
+ }
+ }
+ if(op->flags&OP_RETURN) {
+ if(OP_RETURN==0x48/*returnvalue*/) {
+ if(stack!=1) {
+ stats->stack[pos].flags |= FLAG_ERROR;
+ fprintf(stderr, "return(value) with stackposition %d\n", stack);
+ }
+ } else if(OP_RETURN==0x47) {
+ if(stack!=0) {
+ stats->stack[pos].flags |= FLAG_ERROR;
+ fprintf(stderr, "return(void) with stackposition %d\n", stack);
+ }
+ }
+ }
+ if(op->flags & (OP_THROW|OP_RETURN))
+ return 1;
+ if(op->flags & OP_JUMP) {
+ if(!c->branch) {
+ stats->stack[pos].flags |= FLAG_ERROR;
+ fprintf(stderr, "Error: Invalid jump target in instruction %s at position %d.\n", op->name, pos);
+ return 0;
+ }
+ c = c->branch;
+ pos = c->pos;
+ continue;
+ }
+ if(op->flags & OP_BRANCH) {
+ if(!c->branch) {
+ stats->stack[pos].flags |= FLAG_ERROR;
+ fprintf(stderr, "Error: Invalid jump target in instruction %s at position %d\n", op->name, pos);
+ return 0;
+ }
+ int newpos = c->branch->pos;
+ if(!callcode(stats, newpos, stack, scope))
+ return 0;
+ }
+ if(op->flags & OP_LOOKUPSWITCH) {
+ lookupswitch_t*l = c->data[0];
+ if(!l->def) {
+ stats->stack[pos].flags |= FLAG_ERROR;
+ fprintf(stderr, "Error: Invalid jump target in instruction %s at position %d\n", op->name, pos);
+ return 0;
+ }
+ if(!callcode(stats, l->def->pos, stack, scope))
+ return 0;
+ code_list_t*t = l->targets;
+ while(t) {
+ if(!t->code) {
+ stats->stack[pos].flags |= FLAG_ERROR;
+ fprintf(stderr, "Error: Invalid jump target in instruction %s at position %d\n", op->name, pos);
+ return 0;
+ }
+ if(!callcode(stats, t->code->pos, stack, scope))
+ return 0;
+ t = t->next;
+ }
+ }
+
+ pos++;
+ if(pos<stats->num) {
+ assert(c->next == stats->stack[pos].code);
+ }
+ }
+ return 1;
+}
+
+static currentstats_t* code_get_stats(code_t*code, abc_exception_list_t*exceptions)
+{
+ code = code_start(code);
+ int num = 0;
+ code_t*c = code;
+ while(c) {
+ num++;
+ c = c->next;
+ }
+ currentstats_t* current = malloc(sizeof(currentstats_t));
+ current->stack = rfx_calloc(sizeof(stackpos_t)*num);
+ current->maxlocal = 0;
+ current->maxstack = 0;
+ current->maxscope = 0;
+ current->num = num;
+ current->flags = 0;
+
+//#define DEBUG_BYTES
+#ifdef DEBUG_BYTES
+ int t;
+ c = code;
+ for(t=0;t<num;t++) {
+ opcode_t*op = opcode_get(c->opcode);
+ if(op->flags & (OP_JUMP|OP_BRANCH)) {
+ printf("%05d) %s %08x\n", t, op->name, c->branch);
+ } else if(op->params[0]=='2') {
+ printf("%05d) %s %s\n", t, op->name, multiname_tostring(c->data[0]));
+ } else if(op->params[0]=='N') {
+ printf("%05d) %s %s\n", t, op->name, namespace_tostring(c->data[0]));
+ } else {
+ printf("%05d) %s\n", t, op->name);
+ }
+ c = c->next;
+ }
+ //printf("%05d) %02x\n", t, tag->data[start+t]);
+#endif
+
+ num = 0;
+ c = code;
+ while(c) {
+ //crosslink
+ current->stack[num].code = c;
+ c->pos = num;
+ num++;
+ c = c->next;
+ }
+
+ if(!callcode(current, 0, 0, 0)) {
+ free(current);
+ return 0;
+ }
+ abc_exception_list_t*e = exceptions;
+ while(e) {
+ if(e->abc_exception->target)
+ callcode(current, e->abc_exception->target->pos, 1, 0);
+ e = e->next;
+ }
+
+ return current;
+}
+
+void stats_free(currentstats_t*stats)
+{
+ if(stats) {
+ free(stats->stack);stats->stack=0;
+ free(stats);
+ }
+}
+
+int code_dump(code_t*c)
+{
+ code_t*cc = code_start(c);
+ while(cc) {
+ assert(!cc->next || cc->next->prev == cc);
+ cc = cc->next;
+ }
+
+ return code_dump2(c, 0, 0, "", stdout);
+}
+int code_dump2(code_t*c, abc_exception_list_t*exceptions, abc_file_t*file, char*prefix, FILE*fo)
+{
+ abc_exception_list_t*e = exceptions;
+ c = code_start(c);
+ currentstats_t*stats = code_get_stats(c, exceptions);
+
+ int pos = 0;
while(c) {
U8 opcode = c->opcode;
- int t;
char found = 0;
opcode_t*op = opcode_get(opcode);
+
+ e = exceptions;
+ while(e) {
+ if(c==e->abc_exception->from)
+ fprintf(fo, "%s TRY {\n", prefix);
+ if(c==e->abc_exception->target) {
+ char*s1 = multiname_tostring(e->abc_exception->exc_type);
+ char*s2 = multiname_tostring(e->abc_exception->var_name);
+ fprintf(fo, "%s CATCH(%s %s)\n", prefix, s1, s2);
+ free(s1);
+ free(s2);
+ }
+ e = e->next;
+ }
+
if(!op) {
fprintf(stderr, "Can't parse opcode %02x.\n", opcode);
return 0;
} else {
- fprintf(fo, "%s%s ", prefix, op->name);
char*p = op->params;
char first = 1;
- int pos=0;
+ int i=0;
+
+ if(stats) {
+ int f = stats->stack[c->pos].flags;
+ fprintf(fo, "%s%05d) %c %d:%d %s ", prefix, c->pos,
+ (f&FLAG_ERROR)?'E':((f&FLAG_SEEN)?'+':'|'),
+ stats->stack[c->pos].stackpos,
+ stats->stack[c->pos].scopepos,
+ op->name);
+ } else {
+ fprintf(fo, "%s%05d) ? ?:? %s ", prefix, c->pos, op->name);
+ }
+
while(*p) {
- void*data = c->params[pos];
- if(pos>0)
+ void*data = c->data[i];
+ if(i>0)
printf(", ");
if(*p == 'n') {
fprintf(fo, "%d params", n);
} else if(*p == '2') {
multiname_t*n = (multiname_t*)data;
- char* m = multiname_to_string(n);
+ char* m = multiname_tostring(n);
+ fprintf(fo, "%s", m);
+ free(m);
+ } else if(*p == 'N') {
+ namespace_t*ns = (namespace_t*)data;
+ char* m = namespace_tostring(ns);
fprintf(fo, "%s", m);
free(m);
} else if(*p == 'm') {
abc_method_t*m = (abc_method_t*)data;
- fprintf(fo, "[method %s]", m->name);
+ fprintf(fo, "[method %08x %s]", m->index, m->name);
} else if(*p == 'c') {
abc_class_t*cls = (abc_class_t*)data;
- char*classname = multiname_to_string(cls->classname);
- fprintf(fo, "[classinfo %s]", classname);
+ char*classname = multiname_tostring(cls->classname);
+ fprintf(fo, "[classinfo %08x %s]", cls->index, classname);
free(classname);
} else if(*p == 'i') {
abc_method_body_t*b = (abc_method_body_t*)data;
fprintf(fo, "[methodbody]");
- } else if(*p == 'u') {
+ } else if(*p == 'u' || *p == 'I' || *p == 'U') {
int n = (ptroff_t)data;
fprintf(fo, "%d", n);
+ } else if(*p == 'f') {
+ double f = *(double*)data;
+ fprintf(fo, "%f", f);
} else if(*p == 'r') {
int n = (ptroff_t)data;
fprintf(fo, "r%d", n);
} else if(*p == 'b') {
- int b = (ptroff_t)data;
- fprintf(fo, "%02x", b);
+ int b = (signed char)(ptroff_t)data;
+ fprintf(fo, "%d", b);
} else if(*p == 'j') {
- int n = (ptroff_t)data;
- fprintf(fo, "%d", n);
+ if(c->branch)
+ fprintf(fo, "->%d", c->branch->pos);
+ else
+ fprintf(fo, "%08x", (unsigned int)c->branch);
} else if(*p == 's') {
- fprintf(fo, "\"%s\"", data);
+ char*s = string_escape((string_t*)data);
+ fprintf(fo, "\"%s\"", s);
+ free(s);
} else if(*p == 'D') {
- fprintf(fo, "[register %02x=%s]", (ptroff_t)c->params[1], (char*)c->params[0]);
+ fprintf(fo, "[register %02x=%s]", (ptroff_t)c->data[1], (char*)c->data[0]);
} else if(*p == 'S') {
- fprintf(fo, "[switch data]");
+ lookupswitch_t*l = c->data[0];
+ fprintf(fo, "[");
+ if(l->def)
+ fprintf(fo, "default->%d", l->def->pos);
+ else
+ fprintf(fo, "default->00000000");
+ code_list_t*t = l->targets;
+ while(t) {
+ if(t->code)
+ fprintf(fo, ",->%d", t->code->pos);
+ else
+ fprintf(fo, ",->00000000");
+ t = t->next;
+ }
+ fprintf(fo, "]");
} else {
fprintf(stderr, "Can't parse opcode param type \"%c\"\n", *p);
return 0;
}
p++;
- pos++;
+ i++;
first = 0;
}
fprintf(fo, "\n");
}
+
+ e = exceptions;
+ while(e) {
+ if(c==e->abc_exception->to) {
+ if(e->abc_exception->target)
+ fprintf(fo, "%s } // END TRY (HANDLER: %d)\n", prefix, e->abc_exception->target->pos);
+ else
+ fprintf(fo, "%s } // END TRY (HANDLER: 00000000)\n", prefix);
+ }
+ e = e->next;
+ }
+
+ pos++;
c = c->next;
}
+ stats_free(stats);
return 1;
}
-int opcode_write(TAG*tag, abc_code_t*code, pool_t*pool, abc_file_t*file)
+codestats_t* code_get_statistics(code_t*code, abc_exception_list_t*exceptions)
{
- opcode_t*c = opcode_get(code->opcode);
- char*p = c->params;
- int pos = 0;
- int len = 0;
-
- if(tag)
- swf_SetU8(tag, code->opcode);
- len++;
+ currentstats_t*current = code_get_stats(code, exceptions);
+ if(!current)
+ return 0;
+ codestats_t*stats = rfx_calloc(sizeof(codestats_t));
+ stats->local_count = current->maxlocal;
+ stats->max_stack = current->maxstack;
+ stats->max_scope_depth = current->maxscope;
+ stats->flags = current->flags;
- while(*p) {
- void*data = code->params[pos++];
- assert(pos<=2);
- if(*p == 'n') { // number
- len += swf_SetU30(tag, (ptroff_t)data);
- } else if(*p == '2') { //multiname
- multiname_t*m = (multiname_t*)data;
- len += swf_SetU30(tag, pool_register_multiname(pool, m));
- } else if(*p == 'm') { //method
- abc_method_t*m = (abc_method_t*)data;
- len += swf_SetU30(tag, m->index);
- } else if(*p == 'c') { //classinfo
- abc_class_t*cls = (abc_class_t*)data;
- len += swf_SetU30(tag, cls->index);
- } else if(*p == 'i') { //methodbody
- abc_method_body_t*m = (abc_method_body_t*)data;
- len += swf_SetU30(tag, m->index);
- } else if(*p == 'u') { // integer
- len += swf_SetU30(tag, (ptroff_t)data);
- } else if(*p == 'r') { // integer
- len += swf_SetU30(tag, (ptroff_t)data);
- } else if(*p == 'b') { // byte
- if(tag)
- swf_SetU8(tag, (ptroff_t)data);
- len++;
- } else if(*p == 'j') { // jump
- len += swf_SetS24(tag, (ptroff_t)data);
- } else if(*p == 's') { // string
- int index = pool_register_string(pool, data);
- len += swf_SetU30(tag, index);
- } else if(*p == 'D') { // debug statement
- if(tag)
- swf_SetU8(tag, 1);
- len++;
- len+=swf_SetU30(tag, pool_register_string(pool,code->params[0]));
- if(tag)
- swf_SetU8(tag, (ptroff_t)code->params[1]);
- len++;
- len+=swf_SetU30(tag, 0);
- } else if(*p == 'S') { // switch statement
- len+=swf_SetU24(tag, 0); //default
- len+=swf_SetU30(tag, 0); //nr-1
- len+=swf_SetU24(tag, 0); //first
- } else {
- printf("Can't parse opcode param type \"%c\"\n", *p);
- }
- p++;
- }
- return len;
+ stats_free(current);current=0;
+ return stats;
}
-abc_code_t* add_opcode(abc_code_t*atag, U8 op)
+void codestats_free(codestats_t*s)
{
- abc_code_t*tmp = (abc_code_t*)malloc(sizeof(abc_code_t));
+ free(s);
+}
+
+code_t* add_opcode(code_t*atag, U8 op)
+{
+ code_t*tmp = (code_t*)rfx_calloc(sizeof(code_t));
tmp->opcode = op;
- tmp->next = 0;
if(atag) {
tmp->prev = atag;
+ tmp->next = atag->next;
+ if(tmp->next)
+ tmp->next->prev = tmp;
atag->next = tmp;
- tmp->parent = atag->parent;
} else {
tmp->prev = 0;
- tmp->parent = tmp;
+ tmp->next = 0;
}
return tmp;
}
+
+void codestats_print(codestats_t*stats)
+{
+ printf("max_stack: %d\n", stats->max_stack);
+ printf("local_count: %d\n", stats->local_count);
+ printf("scope_depth: %d\n", stats->max_scope_depth);
+}
+
+code_t* code_end(code_t*code)
+{
+ if(!code)
+ return 0;
+ while(code->next)
+ code = code->next;
+ return code;
+}
+code_t* code_start(code_t*code)
+{
+ if(!code)
+ return 0;
+ while(code->prev)
+ code = code->prev;
+ return code;
+}
+
+code_t* code_append(code_t*code, code_t*toappend)
+{
+ if(!code)
+ return code_end(toappend);
+ if(!toappend)
+ return code_end(code);
+ //find end of first list
+ while(code->next) {
+ code = code->next;
+ }
+ code_t*start=toappend;
+ //and start of second list
+ while(start->prev) {
+ start = start->prev;
+ }
+ code->next = start;
+ start->prev = code;
+ return code_end(toappend);
+}
+
+lookupswitch_t*lookupswitch_dup(lookupswitch_t*l)
+{
+ lookupswitch_t*n = malloc(sizeof(lookupswitch_t));
+ fprintf(stderr, "Error: lookupswitch dupping not supported yet\n");
+ n->targets = list_clone(l->targets);
+ return 0;
+}
+
+code_t*code_dup(code_t*c)
+{
+ if(!c) return 0;
+
+ dict_t*pos2pos = dict_new2(&ptr_type);
+
+ code_t*last = 0;
+ c = code_start(c);
+ code_t*start = 0;
+ char does_branch = 0;
+ while(c) {
+ NEW(code_t, n);
+ memcpy(n, c, sizeof(code_t));
+ if(!start)
+ start=n;
+
+ if(c->opcode == OPCODE_LABEL || c->opcode == OPCODE_NOP) {
+ dict_put(pos2pos, c, n);
+ }
+ if(c->branch) {
+ does_branch = 1;
+ }
+
+ opcode_t*op = opcode_get(c->opcode);
+
+ char*p = op?op->params:"";
+ int pos=0;
+ while(*p) {
+ if(*p == '2') { //multiname
+ c->data[pos] = multiname_clone(c->data[pos]);
+ } else if(*p == 'N') { //multiname
+ c->data[pos] = namespace_clone(c->data[pos]);
+ } else if(*p == 's') {
+ c->data[pos] = string_dup3(c->data[pos]);
+ } else if(*p == 'D') {
+ c->data[pos] = strdup(c->data[pos]);
+ } else if(*p == 'f') {
+ double old = *(double*)c->data[pos];
+ c->data[pos] = malloc(sizeof(double));
+ *(double*)c->data[pos] = old;
+ } else if(strchr("S", *p)) {
+ c->data[pos] = lookupswitch_dup(c->data[pos]);
+ }
+ p++;pos++;
+ }
+
+ n->prev = last;
+ if(last) {
+ last->next = n;
+ }
+ last = n;
+ c = c->next;
+ }
+
+ if(does_branch) {
+ c = start;
+ while(c) {
+ if(c->branch) {
+ code_t*target = dict_lookup(pos2pos, c->branch);
+ if(!target) {
+ fprintf(stderr, "Error: Can't find branch target in code_dup\n");
+ return 0;
+ }
+ c->branch = target;
+ }
+ c = c->next;
+ }
+ }
+ dict_destroy(pos2pos);
+ return last;
+}
+
+code_t*code_cut(code_t*c)
+{
+ if(!c) return c;
+ code_t*prev = c->prev;
+ code_t*next = c->next;
+ c->prev = 0;
+ c->next = 0;
+ if(prev) prev->next=next;
+ if(next) next->prev=prev;
+ code_free(c);
+
+ if(next) return code_end(next);
+ else return prev;
+}
+
+code_t*code_cutlast(code_t*c)
+{
+ if(!c) return c;
+ assert(!c->next);
+ return code_cut(c);
+}
+
+char is_getlocal(code_t*c)
+{
+ if(!c) return 0;
+ if(c->opcode == OPCODE_GETLOCAL ||
+ c->opcode == OPCODE_GETLOCAL_0 ||
+ c->opcode == OPCODE_GETLOCAL_1 ||
+ c->opcode == OPCODE_GETLOCAL_2 ||
+ c->opcode == OPCODE_GETLOCAL_3) {
+ return 1;
+ }
+ return 0;
+}
+
+code_t* cut_last_push(code_t*c)
+{
+ assert(!c->next);
+ while(c) {
+ if(!c) break;
+ opcode_t*op = opcode_get(c->opcode);
+ /* cut conversion type operations */
+ if(op->stack_minus == -1 && op->stack_plus == 1 && !(op->flags)) {
+ c = code_cutlast(c);
+ continue;
+ }
+ /* cut any type of push */
+ else if(op->stack_minus == 0 && op->stack_plus == 1 && !(op->flags)) {
+ return code_cutlast(c);
+ }
+ /* cut register lookups */
+ else if(c->opcode == OPCODE_GETLOCAL ||
+ c->opcode == OPCODE_GETLOCAL_0 ||
+ c->opcode == OPCODE_GETLOCAL_1 ||
+ c->opcode == OPCODE_GETLOCAL_2 ||
+ c->opcode == OPCODE_GETLOCAL_3) {
+ return code_cutlast(c);
+ }
+ /* discard function call values */
+ else if(c->opcode == OPCODE_CALLPROPERTY) {
+ c->opcode = OPCODE_CALLPROPVOID;
+ return c;
+ } else if(c->opcode == OPCODE_CALLSUPER) {
+ c->opcode = OPCODE_CALLSUPERVOID;
+ return c;
+ } else if((c->opcode == OPCODE_NEWOBJECT ||
+ c->opcode == OPCODE_NEWARRAY) &&
+ !c->data[0]) {
+ // we can discard these if they're not eating up stack parameters
+ return code_cutlast(c);
+ } else if(op->stack_minus ==0 && op->stack_plus == 0 &&
+ !(op->flags&~(OP_REGISTER|OP_SET_DXNS)) && c->prev) {
+ // trim code *before* the kill, inclocal, declocal, dxns
+ code_t*p = c->prev;
+ p->next = 0;
+ c->prev = 0;
+ return code_append(cut_last_push(p), c);
+ } else
+ break;
+ }
+ c = abc_pop(c);
+ return c;
+}
+