optimizations and bugfixes for finally

[swftools.git] / lib / as3 / code.c

diff --git a/lib/as3/code.c b/lib/as3/code.c
index 628f4d8..d5c3acf 100644 (file)
--- a/lib/as3/code.c
+++ b/lib/as3/code.c
@@ -37,6 +37,7 @@
 #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
@@ -199,8 +200,10 @@ opcode_t opcodes[]={
 //0x53: seen in builtin.abc
 {0x53, "applytype", "n",       -1, 1, 0, OP_STACK_ARGS},
 
-/* dummy instruction. Warning: this one is not actually supported by flash */
-{0xff, "__break__", "",             0, 0, 0, OP_RETURN},
+/* dummy instructions. Warning: these are not actually supported by flash */
+{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};
@@ -412,16 +415,9 @@ void codelookup_free(codelookup_t*codelookup)
     free(codelookup);
 }
 
-code_t*code_find_start(code_t*c)
-{
-    while(c && c->prev) 
-        c=c->prev;
-    return c;
-}
-
 void code_free(code_t*c)
 {
-    c = code_find_start(c);
+    c = code_start(c);
     while(c) {
         code_t*next = c->next;
         opcode_t*op = opcode_get(c->opcode);
@@ -458,6 +454,15 @@ static int opcode_write(TAG*tag, code_t*c, pool_t*pool, abc_file_t*file, int len
         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);
@@ -532,7 +537,7 @@ static int opcode_write(TAG*tag, code_t*c, pool_t*pool, abc_file_t*file, int len
 
 void code_write(TAG*tag, code_t*code, pool_t*pool, abc_file_t*file)
 {
-    code = code_find_start(code);
+    code = code_start(code);
     int pos = 0;
     int length = 0;
     code_t*c = code;
@@ -775,7 +780,7 @@ static char callcode(currentstats_t*stats, int pos, int stack, int scope)
 
 static currentstats_t* code_get_stats(code_t*code, abc_exception_list_t*exceptions) 
 {
-    code = code_find_start(code);
+    code = code_start(code);
     int num = 0;
     code_t*c = code;
     while(c) {
@@ -843,7 +848,7 @@ void stats_free(currentstats_t*stats)
 int code_dump(code_t*c, abc_exception_list_t*exceptions, abc_file_t*file, char*prefix, FILE*fo)
 {
     abc_exception_list_t*e = exceptions;
-    c = code_find_start(c);
+    c = code_start(c);
     currentstats_t*stats =  code_get_stats(c, exceptions);
 
     int pos = 0;
@@ -900,7 +905,7 @@ int code_dump(code_t*c, abc_exception_list_t*exceptions, abc_file_t*file, char*p
                     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, m->name);
                 } else if(*p == 'c') {
                     abc_class_t*cls = (abc_class_t*)data;
                     char*classname = multiname_tostring(cls->classname);
@@ -1027,6 +1032,14 @@ code_t* code_end(code_t*code)
         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)
 {
@@ -1068,7 +1081,7 @@ code_t*code_dup(code_t*c)
         memcpy(n, c, sizeof(code_t));
 
         opcode_t*op = opcode_get(c->opcode);
-        if(c->branch) {
+        if(c->branch || c->opcode == OPCODE_LABEL) {
             fprintf(stderr, "Error: Can't duplicate branching code\n");
             return 0;
         }
@@ -1101,20 +1114,31 @@ code_t*code_dup(code_t*c)
     return last;
 }
 
-code_t*code_cutlast(code_t*c)
+code_t*code_cut(code_t*c)
 {
     if(!c) return c;
-    assert(!c->next);
     code_t*prev = c->prev;
+    code_t*next = c->next;
     c->prev = 0;
-    if(prev)
-        prev->next=0;
+    c->next = 0;
+    if(prev) prev->next=next;
+    if(next) next->prev=prev;
     code_free(c);
-    return prev;
+    
+    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);
@@ -1142,8 +1166,19 @@ code_t* cut_last_push(code_t*c)
         } else if(c->opcode == OPCODE_CALLSUPER) {
             c->opcode = OPCODE_CALLSUPERVOID;
             return c;
-        }
-        else
+        } else if(c->opcode == OPCODE_NEWOBJECT ||
+                  c->opcode == OPCODE_NEWARRAY) {
+            // we can discard these if they're not eating up stack parameters
+            if(!c->data[0])
+                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);