X-Git-Url: http://git.asbjorn.biz/?a=blobdiff_plain;f=lib%2Fas3%2Fcode.c;h=31c986f2fdaa66109f8536973c5581dc9a4e35be;hb=b8aa0577aae67db4da5221459102202febc5c103;hp=78d5c760e73998b987b384f0d8b39c9560ff39a3;hpb=f13e4b6d437233b91c39f577ca3ae63a54269675;p=swftools.git

diff --git a/lib/as3/code.c b/lib/as3/code.c
index 78d5c76..31c986f 100644
--- a/lib/as3/code.c
+++ b/lib/as3/code.c
@@ -1,5 +1,29 @@
+/* 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
@@ -7,34 +31,36 @@
 #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},
 {0x4c, "callproplex", "2n",    -1, 1, 0, OP_STACK_ARGS|OP_STACK_NS},
@@ -49,7 +75,7 @@ opcode_t opcodes[]={
 {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},
@@ -86,7 +112,8 @@ opcode_t opcodes[]={
 {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},
@@ -108,7 +135,7 @@ opcode_t opcodes[]={
 {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},
@@ -117,7 +144,7 @@ opcode_t opcodes[]={
 {0x09, "label", "",             0, 0, 0, OP_LABEL},
 {0xae, "lessequals", "",       -2, 1, 0, 0},
 {0xad, "lessthan", "",         -2, 1, 0, 0},
-{0x1b, "lookupswitch", "S",    -1, 0, 0, OP_SWITCH},
+{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},
@@ -137,17 +164,17 @@ opcode_t opcodes[]={
 {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},
@@ -160,7 +187,7 @@ opcode_t opcodes[]={
 {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},
@@ -169,34 +196,82 @@ opcode_t opcodes[]={
 {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];
+}
+
+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)
+{
+    return pos2code(l->bytepos, 0, pos, l->len);
 }
 
-abc_code_t*code_parse(TAG*tag, int len, abc_file_t*file, pool_t*pool)
+void lookupswitch_print(lookupswitch_t*l)
 {
-    abc_code_t*head=0;
-    abc_code_t*code=0;
+    printf("default: %08x\n", l->def);
+    code_list_t*t = l->targets;
+    while(t) {
+        printf("target: %08x\n", 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);
 
-    abc_code_t**bytepos = rfx_calloc(sizeof(abc_code_t*)*len);
+    code_t**bytepos = rfx_calloc(sizeof(code_t*)*len);
         
     while(tag->pos<end) {
         int codepos = tag->pos-start;
@@ -204,10 +279,10 @@ abc_code_t*code_parse(TAG*tag, int len, abc_file_t*file, pool_t*pool)
         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;
@@ -216,6 +291,7 @@ abc_code_t*code_parse(TAG*tag, int len, abc_file_t*file, pool_t*pool)
             head = code = c;
         } else {
             code->next = c;
+            c->prev = code;
             code = c;
         }
 
@@ -229,6 +305,16 @@ abc_code_t*code_parse(TAG*tag, int len, abc_file_t*file, pool_t*pool)
                 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
@@ -245,7 +331,8 @@ abc_code_t*code_parse(TAG*tag, int len, abc_file_t*file, pool_t*pool)
                 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);
@@ -257,16 +344,17 @@ abc_code_t*code_parse(TAG*tag, int len, abc_file_t*file, pool_t*pool)
                 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)
@@ -279,52 +367,62 @@ abc_code_t*code_parse(TAG*tag, int len, abc_file_t*file, pool_t*pool)
 #ifdef DEBUG_BYTES
     int t;
     for(t=0;t<len;t++) {
-        abc_code_t*c = bytepos[t];
+        code_t*c = bytepos[t];
         if(c) {
             opcode_t*op = opcode_get(c->opcode);
             if(op->flags & (OP_JUMP|OP_BRANCH)) {
-                printf("%5d) %02x %s %d\n", t, tag->data[start+t], op->name, c->data[0]);
+                printf("%50d) %02x %s %d\n", t, tag->data[start+t], op->name, c->data[0]);
             } else {
-                printf("%5d) %02x %s\n", t, tag->data[start+t], op->name);
+                printf("%50d) %02x %s\n", t, tag->data[start+t], op->name);
             }
         } else {
-            printf("%5d) %02x\n", t, tag->data[start+t]);
+            printf("%50d) %02x\n", t, tag->data[start+t]);
         }
     }
-    printf("%5d) %02x\n", t, tag->data[start+t]);
+    //printf("%05d) %02x\n", t, tag->data[start+t]);
 #endif
 
-    abc_code_t*c = head;
+    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]) + 4;
-#ifdef DEBUG_BYTES
-            printf("%s %d %d\n", op->name, c->pos, j);
-#endif
-            if(c->pos+j < 0 ||
-               c->pos+j > len ||
-              (c->pos+j!=len && !bytepos[c->pos+j])) {
-                /* flex likes to generate these. yuck. */
-                fprintf(stderr, "Invalid jump instruction \"%s\" from %d to %d (%d)\n", op->name, c->pos, c->pos+j, len);
-                code->branch = 0;
-            } else {
-                if(c->pos==len)
-                    code->branch = 0;
-                else
-                    code->branch = bytepos[c->pos+j];
+            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;
     } 
-    free(bytepos);
+
+    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;
@@ -332,8 +430,14 @@ void code_free(abc_code_t*c)
             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->data[pos]=0;
             p++;pos++;
@@ -344,150 +448,143 @@ void code_free(abc_code_t*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();
-
-    while(c) {
-	U8 opcode = c->opcode;
-	int t;
-	char found = 0;
-        opcode_t*op = opcode_get(opcode);
-	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;
-            while(*p) {
-                void*data = c->data[pos];
-                if(pos>0)
-                    printf(", ");
-
-                if(*p == 'n') {
-                    int n = (ptroff_t)data;
-                    fprintf(fo, "%d params", n);
-                } else if(*p == '2') {
-                    multiname_t*n = (multiname_t*)data;
-                    char* m = multiname_to_string(n);
-                    fprintf(fo, "%s", m);
-                    free(m);
-                } else if(*p == 'm') {
-                    abc_method_t*m = (abc_method_t*)data;
-                    fprintf(fo, "[method %s]", 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);
-                    free(classname);
-                } else if(*p == 'i') {
-                    abc_method_body_t*b = (abc_method_body_t*)data;
-                    fprintf(fo, "[methodbody]");
-                } else if(*p == 'u') {
-                    int n = (ptroff_t)data;
-                    fprintf(fo, "%d", n);
-                } 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);
-                } else if(*p == 'j') {
-                    int n = (ptroff_t)data;
-                    fprintf(fo, "%d", n);
-                } else if(*p == 's') {
-                    fprintf(fo, "\"%s\"", data);
-                } else if(*p == 'D') {
-                    fprintf(fo, "[register %02x=%s]", (ptroff_t)c->data[1], (char*)c->data[0]);
-                } else if(*p == 'S') {
-                    fprintf(fo, "[switch data]");
-                } else {
-                    fprintf(stderr, "Can't parse opcode param type \"%c\"\n", *p);
-                    return 0;
-                }
-                p++;
-                pos++;
-                first = 0;
-            }
-            fprintf(fo, "\n");
-	}
-        c = c->next;
-    }
-    return 1;
-}
-
-static int opcode_write(TAG*tag, abc_code_t*code, pool_t*pool, abc_file_t*file)
-{
-    opcode_t*op = opcode_get(code->opcode);
+    opcode_t*op = opcode_get(c->opcode);
     char*p = op->params;
     int pos = 0;
     int len = 0;
-    
+
     if(tag)
-        swf_SetU8(tag, code->opcode);
+        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 = code->data[pos++];
+        void*data = c->data[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->data[0]));
-            if(tag)
-                swf_SetU8(tag, (ptroff_t)code->data[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);
+        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, abc_code_t*code, pool_t*pool, abc_file_t*file)
+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;
-    abc_code_t*c = code;
+    code_t*c = code;
     while(c) {
         c->pos = pos;
-        pos += opcode_write(0, c, pool, file);
+        pos += opcode_write(0, c, pool, file, 0);
         c = c->next;
     }
     length = pos;
@@ -499,24 +596,19 @@ void code_write(TAG*tag, abc_code_t*code, pool_t*pool, abc_file_t*file)
         opcode_t*op = opcode_get(code->opcode);
         if(op->flags&(OP_BRANCH|OP_JUMP)) {
             int skip = 0;
-            if(c->branch)
-                skip = (c->branch->pos) - pos - 4;
-            else
-                skip = length - pos - 4;
-            c->data[0] = (void*)(ptroff_t)skip;
         }
-        pos += opcode_write(tag, c, pool, file);
+        pos += opcode_write(tag, c, pool, file, length);
         c = c->next;
     }
     assert(tag->len - start == pos);
 }
 
-
 typedef struct {
     int stackpos;
     int scopepos;
-    abc_code_t*code;
-    char seen;
+    code_t*code;
+    char flags;
+    char error;
 } stackpos_t;
 
 typedef struct {
@@ -525,19 +617,22 @@ typedef struct {
     int maxlocal;
     int maxstack;
     int maxscope;
+    int flags;
 } currentstats_t;
 
-static int stack_minus(abc_code_t*c)
+static int stack_minus(code_t*c)
 {
     opcode_t*op = opcode_get(c->opcode);
-    assert(op->stack_minus<=0);
+    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];
-        stack--; //read namespace
-        if(m->type == RTQNAMEL || m->type == RTQNAMELA) {
-            stack--; //read name
-        }
+        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'));
@@ -550,32 +645,76 @@ static int stack_minus(abc_code_t*c)
 }
 static void handleregister(currentstats_t*stats, int reg)
 {
-    if(reg > stats->maxlocal)
-        stats->maxlocal = reg;
+    if(reg+1 > stats->maxlocal)
+        stats->maxlocal = reg+1;
 }
 
-static void callcode(currentstats_t*stats, int pos, int stack, int scope)
+#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].seen) {
+        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;
+            return 1;
         }
-        stats->stack[pos].seen = 1;
+    
+        stats->stack[pos].flags |= FLAG_SEEN;
         stats->stack[pos].stackpos = stack;
         stats->stack[pos].scopepos = scope;
 
-        abc_code_t*c = stats->stack[pos].code;
+        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);
-            return;
+           
+            /* 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;
@@ -585,6 +724,22 @@ static void callcode(currentstats_t*stats, int pos, int stack, int scope)
             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;
@@ -601,16 +756,61 @@ static void callcode(currentstats_t*stats, int pos, int stack, int scope)
                 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;
+            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;
-            callcode(stats, newpos, stack, scope);
+            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++;
@@ -618,55 +818,460 @@ static void callcode(currentstats_t*stats, int pos, int stack, int scope)
             assert(c->next == stats->stack[pos].code);
         }
     }
+    return 1;
 }
 
-codestats_t code_get_statistics(abc_code_t*code) 
+static currentstats_t* code_get_stats(code_t*code, abc_exception_list_t*exceptions) 
 {
+    code = code_start(code);
     int num = 0;
-    abc_code_t*c = code;
+    code_t*c = code;
     while(c) {
         num++;
         c = c->next;
     }
-    currentstats_t current;
-    current.stack = rfx_calloc(sizeof(stackpos_t)*num);
-    current.maxlocal = 0;
-    current.maxstack = 0;
-    current.maxscope = 0;
-    current.num = num;
+    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;
+        current->stack[num].code = c;
         c->pos = num;
         num++;
         c = c->next;
     }
-    callcode(&current, 0, 0, 0);
 
-    free(current.stack);
+    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;
+	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 {
+            char*p = op->params;
+            char first = 1;
+            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->data[i];
+                if(i>0)
+                    printf(", ");
+
+                if(*p == 'n') {
+                    int n = (ptroff_t)data;
+                    fprintf(fo, "%d params", n);
+                } else if(*p == '2') {
+                    multiname_t*n = (multiname_t*)data;
+                    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 %08x %s]", m->index, m->name);
+                } else if(*p == 'c') {
+                    abc_class_t*cls = (abc_class_t*)data;
+                    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' || *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 = (signed char)(ptroff_t)data;
+                    fprintf(fo, "%d", b);
+                } else if(*p == 'j') {
+                    if(c->branch)
+                        fprintf(fo, "->%d", c->branch->pos);
+                    else
+                        fprintf(fo, "%08x", c->branch);
+                } else if(*p == 's') {
+                    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->data[1], (char*)c->data[0]);
+                } else if(*p == 'S') {
+                    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++;
+                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;
+}
+
+codestats_t* code_get_statistics(code_t*code, abc_exception_list_t*exceptions) 
+{
+    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;
 
-    codestats_t stats;
-    stats.local_count = current.maxlocal;
-    stats.max_stack = current.maxstack;
-    stats.max_scope_depth = current.maxscope;
+    stats_free(current);current=0;
     return stats;
 }
-abc_code_t* add_opcode(abc_code_t*atag, U8 op)
+
+void codestats_free(codestats_t*s)
+{
+    free(s);
+}
+
+code_t* add_opcode(code_t*atag, U8 op)
 {
-    abc_code_t*tmp = (abc_code_t*)malloc(sizeof(abc_code_t));
+    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);
+}
+
+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;
+}
+