variables can be used before definition

change program to command line
change trace back info
change print function of nasal_vec and nasal_hash

README.md

@@ -844,5 +844,9 @@ You will get an error of 'undefined symbol', instead of nothing happening in mos
 This change is __controversial__ among FGPRC's members.
 So maybe in the future i will use dynamic analysis again to cater to the habits of senior programmers.
 
+(2021/8/3 update) __Now i use scanning ast twice to reload symbols.
+So this difference does not exist from this update.__
+But a new difference is that if you call a variable before defining it, you'll get nil instead of 'undefined error'.
+
 In this new interpreter, function doesn't put dynamic arguments into vector 'arg' automatically.
 So if you use 'arg' without definition, you'll get an error of 'undefined symbol'.

main.cpp

@@ -1,42 +1,30 @@
 #include "nasal.h"
 
-void help_interact()
-{
-	std::cout
-	<<">> [     ] input a file name to execute.  \n"
-	<<">> [help ] show help.                     \n"
-	<<">> [ast  ] view abstract syntax tree.     \n"
-	<<">> [code ] view byte code.                \n"
-	<<">> [exec ] execute program on bytecode vm.\n"
-	<<">> [logo ] print logo of nasal .          \n"
-	<<">> [exit ] quit nasal interpreter.        \n";
-	return;
-}
 void help_cmd()
 {
 	std::cout
 #ifdef _WIN32
 	<<"use command \'chcp 65001\' if want to use unicode.\n"
 #endif
-	<<"nasal [option]|[file]\n"
+	<<"nasal [option]\n"
-	<<"    input 0 argument to use the interactive interpreter.\n"
 	<<"option:\n"
 	<<"    -h, --help    | get help.\n"
-	<<"    -v, --version | get version of nasal interpreter.\n"
+	<<"    -v, --version | get version of nasal interpreter.\n\n"
+	<<"nasal [file]\n"
+	<<"file:\n"
+	<<"    input file name to execute script file.\n\n"
+	<<"nasal [option] [file]\n"
+	<<"option:\n"
+	<<"    --lex         | view token info.\n"
+	<<"    --ast         | view abstract syntax tree.\n"
+	<<"    --code        | view bytecode.\n"
+	<<"    --exec        | execute script file.\n"
+	<<"    --time        | execute and get the running time.\n"
 	<<"file:\n"
 	<<"    input file name to execute script file.\n";
 	return;
 }
-void info()
+
-{
-	std::cout
-	<<">> thanks to https://github.com/andyross/nasal\n"
-	<<">> code: https://github.com/ValKmjolnir/Nasal-Interpreter\n"
-	<<">> code: https://gitee.com/valkmjolnir/Nasal-Interpreter\n"
-	<<">> info: http://wiki.flightgear.org/Nasal_scripting_language\n"
-	<<">> input \"help\" to get help .\n";
-	return;
-}
 void logo()
 {
     std::cout
@@ -45,14 +33,21 @@ void logo()
 	<<"   /  \\/ / _` / __|/ _` | |    \n"
 	<<"  / /\\  / (_| \\__ \\ (_| | |  \n"
 	<<"  \\_\\ \\/ \\__,_|___/\\__,_|_|\n"
-	<<"   nasal interpreter ver 7.0    \n";
+	<<"nasal interpreter ver 7.0\n"
+	<<"thanks to : https://github.com/andyross/nasal\n"
+	<<"code repo : https://github.com/ValKmjolnir/Nasal-Interpreter\n"
+	<<"code repo : https://gitee.com/valkmjolnir/Nasal-Interpreter\n"
+	<<"lang info : http://wiki.flightgear.org/Nasal_scripting_language\n"
+	<<"input \"nasal -h\" to get help .\n";
     return;
 }
+
 void die(const char* stage,std::string& filename)
 {
-	std::cout<<">> ["<<stage<<"] in <\""<<filename<<"\">: error(s) occurred,stop.\n";
+	std::cout<<">> ["<<stage<<"] in <"<<filename<<">: error(s) occurred,stop.\n";
 	return;
 }
+
 void execute(std::string& file,std::string& command)
 {
 	nasal_lexer   lexer;
@@ -67,13 +62,18 @@ void execute(std::string& file,std::string& command)
 		die("lexer",file);
 		return;
 	}
+	if(command=="--lex")
+	{
+		lexer.print_token();
+		return;
+	}
 	parse.main_process(lexer.get_token_list());
 	if(parse.get_error())
 	{
 		die("parse",file);
 		return;
 	}
-	if(command=="ast")
+	if(command=="--ast")
 	{
 		parse.get_root().print_ast(0);
 		return;
@@ -91,7 +91,7 @@ void execute(std::string& file,std::string& command)
 		die("codegen",file);
 		return;
 	}
-	if(command=="code")
+	if(command=="--code")
 	{
 		codegen.print_byte_code();
 		return;
@@ -101,55 +101,45 @@ void execute(std::string& file,std::string& command)
 		codegen.get_num_table(),
 		import.get_file()
 	);
+	if(command=="--exec")
 		vm.run(codegen.get_exec_code());
+	else if(command=="--time")
+	{
+		clock_t begin=clock();
+		vm.run(codegen.get_exec_code());
+		std::cout<<"process exited after "<<((double)(clock()-begin))/CLOCKS_PER_SEC<<"s.\n";
+	}
 	vm.clear();
 	return;
 }
-void interact()
-{
-#ifdef _WIN32
-	// use chcp 65001 to use unicode io
-	system("chcp 65001");
-#endif
-	std::string command,file="null";
-	logo();
-	info();
-    while(1)
-	{
-		std::cout<<">> ";
-		std::cin>>command;
-		if(command=="help")
-			help_interact();
-		else if(command=="logo")
-			logo();
-		else if(command=="exit")
-			return;
-		else if(command=="ast" || command=="code" || command=="exec")
-			execute(file,command);
-		else
-			file=command;
-	}
-}
 int main(int argc,const char* argv[])
 {
 	std::string command,file="null";
-	if(argc==1)
+	if(argc==2 && (!strcmp(argv[1],"-v") || !strcmp(argv[1],"--version")))
-		interact();
-	else if(argc==2 && (!strcmp(argv[1],"-v") || !strcmp(argv[1],"--version")))
 		logo();
 	else if(argc==2 && (!strcmp(argv[1],"-h") || !strcmp(argv[1],"--help")))
 		help_cmd();
 	else if(argc==2 && argv[1][0]!='-')
 	{
 		file=argv[1];
-		command="exec";
+		command="--exec";
+		execute(file,command);
+	}
+	else if(argc==3 &&
+		(!strcmp(argv[1],"--lex") ||
+		!strcmp(argv[1],"--ast") ||
+		!strcmp(argv[1],"--code") ||
+		!strcmp(argv[1],"--exec") ||
+		!strcmp(argv[1],"--time")))
+	{
+		file=argv[2];
+		command=argv[1];
 		execute(file,command);
-		return 0;
 	}
 	else
 	{
 		std::cout
-		<<"invalid command.\n"
+		<<"invalid argument(s).\n"
 		<<"use nasal -h to get help.\n";
 	}
     return 0;

nasal_builtin.h

@@ -175,7 +175,7 @@ nasal_val* builtin_system(std::vector<nasal_val*>& local_scope,nasal_gc& gc)
         builtin_err("system","\"str\" must be string");
         return nullptr;
     }
-    ret_addr->ptr.num=(double)system(str_addr->ptr.str->data());
+    ret_addr->ptr.num=(double)system(str_addr->ptr.str->c_str());
     return ret_addr;
 }
 
@@ -252,37 +252,38 @@ nasal_val* builtin_fout(std::vector<nasal_val*>& local_scope,nasal_gc& gc)
 
 nasal_val* builtin_split(std::vector<nasal_val*>& local_scope,nasal_gc& gc)
 {
-    nasal_val* delimeter_val_addr=local_scope[1];
+    nasal_val* deli_val_addr=local_scope[1];
-    nasal_val* string_val_addr=local_scope[2];
+    nasal_val* str_val_addr=local_scope[2];
-    if(delimeter_val_addr->type!=vm_str)
+    if(deli_val_addr->type!=vm_str)
     {
         builtin_err("split","\"delimeter\" must be string");
         return nullptr;
     }
-    if(string_val_addr->type!=vm_str)
+    if(str_val_addr->type!=vm_str)
     {
         builtin_err("split","\"string\" must be string");
         return nullptr;
     }
-    std::string delimeter=*delimeter_val_addr->ptr.str;
+    std::string& delimeter=*deli_val_addr->ptr.str;
-    std::string source=*string_val_addr->ptr.str;
+    std::string& source=*str_val_addr->ptr.str;
-    int delimeter_len=delimeter.length();
+    size_t delimeter_len=delimeter.length();
-    int source_len=source.length();
+    size_t source_len=source.length();
-    nasal_val* ret_addr=gc.builtin_alloc(vm_vec);
-    std::vector<nasal_val*>& ref_vec=ret_addr->ptr.vec->elems;
-    std::string tmp="";
 
+    // push it to local scope to avoid being sweeped
+    local_scope.push_back(gc.gc_alloc(vm_vec));
+
+    std::vector<nasal_val*>& vec=local_scope.back()->ptr.vec->elems;
     if(!delimeter_len)
     {
         for(int i=0;i<source_len;++i)
         {
-            nasal_val* str_addr=gc.builtin_alloc(vm_str);
+            vec.push_back(gc.gc_alloc(vm_str));
-            *str_addr->ptr.str=source[i];
+            *vec.back()->ptr.str=source[i];
-            ref_vec.push_back(str_addr);
         }
-        return ret_addr;
+        return local_scope.back();
     }
 
+    std::string tmp="";
     for(int i=0;i<source_len;++i)
     {
         bool check_delimeter=false;
@@ -298,9 +299,8 @@ nasal_val* builtin_split(std::vector<nasal_val*>& local_scope,nasal_gc& gc)
         {
             if(tmp.length())
             {
-                nasal_val* str_addr=gc.builtin_alloc(vm_str);
+                vec.push_back(gc.gc_alloc(vm_str));
-                *str_addr->ptr.str=tmp;
+                *vec.back()->ptr.str=tmp;
-                ref_vec.push_back(str_addr);
                 tmp="";
             }
             i+=delimeter_len-1;
@@ -310,12 +310,11 @@ nasal_val* builtin_split(std::vector<nasal_val*>& local_scope,nasal_gc& gc)
     }
     if(tmp.length())
     {
-        nasal_val* str_addr=gc.builtin_alloc(vm_str);
+        vec.push_back(gc.gc_alloc(vm_str));
-        *str_addr->ptr.str=tmp;
+        *vec.back()->ptr.str=tmp;
-        ref_vec.push_back(str_addr);
         tmp="";
     }
-    return ret_addr;
+    return local_scope.back();
 }
 nasal_val* builtin_rand(std::vector<nasal_val*>& local_scope,nasal_gc& gc)
 {
@@ -330,11 +329,11 @@ nasal_val* builtin_rand(std::vector<nasal_val*>& local_scope,nasal_gc& gc)
         srand((unsigned int)val_addr->ptr.num);
         return gc.nil_addr;
     }
-    double num=0;
+
-    for(int i=0;i<5;++i)
-        num=(num+rand())*(1.0/(RAND_MAX+1.0));
     nasal_val* ret_addr=gc.gc_alloc(vm_num);
-    ret_addr->ptr.num=num;
+    ret_addr->ptr.num=0;
+    for(int i=0;i<5;++i)
+        ret_addr->ptr.num=(ret_addr->ptr.num+rand())*(1.0/(RAND_MAX+1.0));
     return ret_addr;
 }
 nasal_val* builtin_id(std::vector<nasal_val*>& local_scope,nasal_gc& gc)
@@ -342,7 +341,7 @@ nasal_val* builtin_id(std::vector<nasal_val*>& local_scope,nasal_gc& gc)
     nasal_val* val_addr=local_scope[1];
     nasal_val* ret_addr=gc.gc_alloc(vm_str);
     char buf[32];
-    sprintf(buf,"0x%p",val_addr);
+    sprintf(buf,"%p",val_addr);
     *ret_addr->ptr.str=buf;
     return ret_addr;
 }
@@ -652,15 +651,17 @@ nasal_val* builtin_keys(std::vector<nasal_val*>& local_scope,nasal_gc& gc)
         builtin_err("keys","\"hash\" must be hash");
         return nullptr;
     }
-    nasal_val* ret_addr=gc.builtin_alloc(vm_vec);
+
-    std::vector<nasal_val*>& ref_vec=ret_addr->ptr.vec->elems;
+    // push vector into local scope to avoid being sweeped
+    local_scope.push_back(gc.gc_alloc(vm_vec));
+    std::vector<nasal_val*>& vec=local_scope.back()->ptr.vec->elems;
     for(auto iter:hash_addr->ptr.hash->elems)
     {
-        nasal_val* str_addr=gc.builtin_alloc(vm_str);
+        nasal_val* str_addr=gc.gc_alloc(vm_str);
         *str_addr->ptr.str=iter.first;
-        ref_vec.push_back(str_addr);
+        vec.push_back(str_addr);
     }
-    return ret_addr;
+    return local_scope.back();
 }
 nasal_val* builtin_import(std::vector<nasal_val*>& local_scope,nasal_gc& gc)
 {
@@ -799,7 +800,7 @@ nasal_val* builtin_cmp(std::vector<nasal_val*>& local_scope,nasal_gc& gc)
         return nullptr;
     }
     nasal_val* ret_addr=gc.gc_alloc(vm_num);
-    ret_addr->ptr.num=strcmp(a_addr->ptr.str->data(),b_addr->ptr.str->data());
+    ret_addr->ptr.num=strcmp(a_addr->ptr.str->c_str(),b_addr->ptr.str->c_str());
     return ret_addr;
 }
 nasal_val* builtin_chr(std::vector<nasal_val*>& local_scope,nasal_gc& gc)

nasal_codegen.h

@@ -210,6 +210,7 @@ private:
     void die(std::string,int);
     void regist_number(double);
     void regist_string(std::string&);
+    void find_symbol(nasal_ast&);
     void add_sym(std::string&);
     int  local_find(std::string&);
     int  global_find(std::string&);
@@ -278,6 +279,32 @@ void nasal_codegen::regist_string(std::string& str)
     return;
 }
 
+void nasal_codegen::find_symbol(nasal_ast& node)
+{
+    // symbol definition checked here
+    // if find a function, return
+    if(node.get_type()==ast_func)
+        return;
+    // find definition, check
+    else if(node.get_type()==ast_def)
+    {
+        if(node.get_children()[0].get_type()==ast_multi_id)
+            for(auto& i:node.get_children()[0].get_children())
+                add_sym(i.get_str());
+        else
+            add_sym(node.get_children()[0].get_str());
+        find_symbol(node.get_children()[1]);
+    }
+    // find iterator(foreach, forindex), check
+    else if(node.get_type()==ast_new_iter)
+        add_sym(node.get_children()[0].get_str());
+    // check children
+    else
+        for(auto& i:node.get_children())
+            find_symbol(i);
+    return;
+}
+
 void nasal_codegen::add_sym(std::string& name)
 {
     if(local.empty())
@@ -419,6 +446,9 @@ void nasal_codegen::func_gen(nasal_ast& ast)
     gen(op_jmp,0,0);
 
     nasal_ast& block=ast.get_children()[1];
+    // search symbols first, must use after loading parameters
+    // or the location of symbols will change and cause fatal error
+    find_symbol(block);
     block_gen(block);
     for(auto& i:local)
         exec_code[local_label].num+=i.size();
@@ -602,7 +632,6 @@ void nasal_codegen::mcall_hash(nasal_ast& ast)
 void nasal_codegen::single_def(nasal_ast& ast)
 {
     std::string& str=ast.get_children()[0].get_str();
-    add_sym(str);
     calc_gen(ast.get_children()[1]);
     local.empty()?gen(op_loadg,global_find(str),ast.get_line()):gen(op_loadl,local_find(str),ast.get_line());
     return;
@@ -618,7 +647,6 @@ void nasal_codegen::multi_def(nasal_ast& ast)
         {
             calc_gen(vals[i]);
             std::string& str=ids[i].get_str();
-            add_sym(str);
             local.empty()?gen(op_loadg,global_find(str),ids[i].get_line()):gen(op_loadl,local_find(str),ids[i].get_line());
         }
     }
@@ -629,7 +657,6 @@ void nasal_codegen::multi_def(nasal_ast& ast)
         {
             gen(op_callvi,i,ast.get_children()[1].get_line());
             std::string& str=ids[i].get_str();
-            add_sym(str);
             local.empty()?gen(op_loadg,global_find(str),ids[i].get_line()):gen(op_loadl,local_find(str),ids[i].get_line());
         }
         gen(op_pop,0,ast.get_line());
@@ -840,7 +867,6 @@ void nasal_codegen::forindex_gen(nasal_ast& ast)
     if(ast.get_children()[0].get_type()==ast_new_iter)
     {
         std::string& str=ast.get_children()[0].get_children()[0].get_str();
-        add_sym(str);
         local.empty()?
             gen(op_loadg,global_find(str),ast.get_children()[0].get_children()[0].get_line())
             :gen(op_loadl,local_find(str),ast.get_children()[0].get_children()[0].get_line());
@@ -869,7 +895,6 @@ void nasal_codegen::foreach_gen(nasal_ast& ast)
     if(ast.get_children()[0].get_type()==ast_new_iter)
     {
         std::string& str=ast.get_children()[0].get_children()[0].get_str();
-        add_sym(str);
         local.empty()?
             gen(op_loadg,global_find(str),ast.get_children()[0].get_children()[0].get_line())
             :gen(op_loadl,local_find(str),ast.get_children()[0].get_children()[0].get_line());
@@ -1148,6 +1173,9 @@ void nasal_codegen::main_progress(nasal_ast& ast)
 
     global.clear();
     local.clear();
+
+    // search symbols first
+    find_symbol(ast);
     gen(op_intg,0,0);
     for(auto& tmp:ast.get_children())
     {

nasal_gc.h

@@ -96,6 +96,11 @@ nasal_val** nasal_vec::get_mem(int index)
 }
 void nasal_vec::print()
 {
+    if(!elems.size())
+    {
+        std::cout<<"[]";
+        return;
+    }
     std::cout<<'[';  
     for(auto i:elems)
     {
@@ -108,20 +113,19 @@ void nasal_vec::print()
             case vm_hash: i->ptr.hash->print();        break;
             case vm_func: std::cout<<"func(...){...}"; break;
         }
-        std::cout<<',';
+        std::cout<<",]"[i==elems.back()];
     }
-    std::cout<<']';
     return;
 }
 
 /*functions of nasal_hash*/
 nasal_val* nasal_hash::get_val(std::string& key)
 {
-    nasal_val* ret_addr=nullptr;
     if(elems.count(key))
         return elems[key];
     else if(elems.count("parents"))
     {
+        nasal_val* ret_addr=nullptr;
         nasal_val* val_addr=elems["parents"];
         if(val_addr->type==vm_vec)
             for(auto i:val_addr->ptr.vec->elems)
@@ -136,11 +140,11 @@ nasal_val* nasal_hash::get_val(std::string& key)
 }
 nasal_val** nasal_hash::get_mem(std::string& key)
 {
-    nasal_val** mem_addr=nullptr;
     if(elems.count(key))
         return &elems[key];
     else if(elems.count("parents"))
     {
+        nasal_val** mem_addr=nullptr;
         nasal_val* val_addr=elems["parents"];
         if(val_addr->type==vm_vec)
             for(auto i:val_addr->ptr.vec->elems)
@@ -155,6 +159,12 @@ nasal_val** nasal_hash::get_mem(std::string& key)
 }
 void nasal_hash::print()
 {
+    if(!elems.size())
+    {
+        std::cout<<"{}";
+        return;
+    }
+    size_t iter=0;
     std::cout<<'{';
     for(auto& i:elems)
     {
@@ -169,9 +179,8 @@ void nasal_hash::print()
             case vm_hash: tmp->ptr.hash->print();      break;
             case vm_func: std::cout<<"func(...){...}"; break;
         }
-        std::cout<<',';
+        std::cout<<",}"[(++iter)==elems.size()];
     }
-    std::cout<<'}';
     return;
 }
 

nasal_lexer.h

@@ -124,7 +124,7 @@ void nasal_lexer::openfile(std::string& filename)
     if(fin.fail())
     {
 		++error;
-        std::cout<<">> [lexer] cannot open file \""<<filename<<"\".\n";
+        std::cout<<">> [lexer] cannot open file <"<<filename<<">.\n";
 		fin.close();
         return;
     }

nasal_vm.h

@@ -18,10 +18,12 @@ private:
     /* values used for debug */
     std::vector<opcode>      bytecode; // bytecode
     std::vector<std::string> files;    // files
-
+    /* debug functions */
+    void bytecodeinfo(uint32_t);
     void stackinfo(int);
     void die(std::string);
     void stackoverflow();
+    /* vm calculation functions*/
     bool condition(nasal_val*);
     void opr_intg();
     void opr_intl();
@@ -132,6 +134,14 @@ void nasal_vm::clear()
     imm.clear();
     return;
 }
+void nasal_vm::bytecodeinfo(uint32_t p)
+{
+    printf("\t0x%.8x: %s 0x%.8x",p,code_table[bytecode[p].op].name,bytecode[p].num);
+    if(bytecode[p].op==op_callb)
+        printf(":%s",builtin_func[bytecode[p].num].name);
+    printf(" (%s line %d)\n",files[bytecode[p].fidx].c_str(),bytecode[p].line);
+    return;
+}
 void nasal_vm::stackinfo(int limit)
 {
     printf("vm stack(limit %d):\n",limit);
@@ -156,20 +166,12 @@ void nasal_vm::stackinfo(int limit)
 void nasal_vm::die(std::string str)
 {
     printf(">> [vm] error at 0x%.8x: %s\ntrace back:\n",pc,str.c_str());
-    // add error pc into ret_stack
-    ret.push(pc);
     // trace back will use ret_stack
+    bytecodeinfo(pc);
     while(!ret.empty())
     {
-        uint32_t point=ret.top();
+        bytecodeinfo(ret.top());
         ret.pop();
-        printf(
-            "\t0x%.8x: %s 0x%.8x (%s line %d)\n",
-            point,
-            code_table[bytecode[point].op].name,
-            bytecode[point].num,
-            files[bytecode[point].fidx].c_str(),
-            bytecode[point].line);
     }
     stackinfo(10);
     gc.val_stack[STACK_MAX_DEPTH-1]=(nasal_val*)0xffff;
@@ -177,17 +179,21 @@ void nasal_vm::die(std::string str)
 }
 void nasal_vm::stackoverflow()
 {
-    printf(">> [vm] stack overflow\nlast called(limit 10):\n");
+    printf(">> [vm] stack overflow\ntrace back:\n");
-    for(int i=0;i<10 && !ret.empty();++i,ret.pop())
+    for(uint32_t same_cnt=0,point=0,last_point=0;!ret.empty();last_point=point,ret.pop())
     {
-        uint32_t point=ret.top();
+        point=ret.top();
-        printf(
+        if(point!=last_point)
-            "\t0x%.8x: %s 0x%.8x (%s line %d)\n",
+        {
-            point,
+            if(same_cnt)
-            code_table[bytecode[point].op].name,
+            {
-            bytecode[point].num,
+                printf("\t0x%.8x: %d same call(s) ...\n",last_point,same_cnt);
-            files[bytecode[point].fidx].c_str(),
+                same_cnt=0;
-            bytecode[point].line);
+            }
+            bytecodeinfo(point);
+        }
+        else
+            ++same_cnt;
     }
     stackinfo(10);
     return;
@@ -709,7 +715,7 @@ inline void nasal_vm::opr_callh()
 inline void nasal_vm::opr_callfv()
 {
     // get parameter list and function value
-    int args_size=imm[pc];
+    uint32_t args_size=imm[pc];
     nasal_val** vec=stack_top-args_size+1;
     nasal_val* func_addr=vec[-1];
     if(func_addr->type!=vm_func)
@@ -724,8 +730,8 @@ inline void nasal_vm::opr_callfv()
     auto& ref_default=ref_func.default_para;
     auto& ref_closure=gc.local.back();
 
-    int offset=ref_func.offset;
+    uint32_t offset=ref_func.offset;
-    int para_size=ref_func.key_table.size();
+    uint32_t para_size=ref_func.key_table.size();
     // load arguments
     if(args_size<para_size && !ref_default[args_size])
     {
@@ -734,7 +740,7 @@ inline void nasal_vm::opr_callfv()
         return;
     }
     // if args_size>para_size,for 0 to args_size will cause corruption
-    int min_size=std::min(para_size,args_size);
+    uint32_t min_size=std::min(para_size,args_size);
     for(int i=0;i<min_size;++i)
         ref_closure[i+offset]=vec[i];
     for(int i=args_size;i<para_size;++i)
@@ -775,7 +781,7 @@ inline void nasal_vm::opr_callfh()
         die("callfh: special call cannot use dynamic argument");
         return;
     }
-    int offset=ref_func.offset;
+    uint32_t offset=ref_func.offset;
     for(auto& i:ref_func.key_table)
     {
         if(ref_hash.count(i.first))
@@ -938,7 +944,7 @@ inline void nasal_vm::opr_ret()
 }
 void nasal_vm::run(std::vector<opcode>& exec)
 {
-    uint64_t count[op_ret+1]={0};
+    //uint64_t count[op_ret+1]={0};
     void* opr_table[]=
     {
         &&nop,     &&intg,     &&intl,   &&offset,
@@ -970,15 +976,15 @@ void nasal_vm::run(std::vector<opcode>& exec)
         imm.push_back(i.num);
     }
 
+    // set canary and program counter
     auto& canary=gc.val_stack[STACK_MAX_DEPTH-1];
-    // clock_t begin=clock();
     pc=0;
+    // run
     goto *code[pc];
 
 nop:
     if(canary && canary!=(nasal_val*)0xffff)
         stackoverflow();
-    // std::cout<<">> [vm] process exited after "<<((double)(clock()-begin))/CLOCKS_PER_SEC<<"s.\n";
     // debug
     // for(int i=0;i<15;++i)
     // {