codegen.pushBlock4Sym(this);
for(int i=0;i<this.stmt_list.size();i++){
AST stmt=this.stmt_list.get(i);
stmt.genSymTb(codegen);
}
codegen.popBlock4Sym();
return true;
codegen.pushBlock4Sym(this);
for(int i=0;i<this.stmt_list.size();i++){
AST stmt=this.stmt_list.get(i);
if(!stmt.genSymTb(codegen)) return false;
}
codegen.popBlock4Sym();
return true;