systemC2.2与2.0的兼容问题

今天编译一个以前的SystemC程序，当时是在SystemC2.0下写的，用最新的2.2版本编译下来一堆错误，总结一下这些错误分三类：

1.sc_string类型的问题,2.2版本中的sc_string类型已经废除，但在systemc的源代码里能看到如下定义：

 #ifdef SC_USE_SC_STRING_OLDtypedef sc_dt::sc_string_old sc_string;#endif#ifdef SC_USE_STD_STRINGtypedef ::std::string sc_string;#endif

sc_string_old 取代了sc_string

SystemC标准里给的解释是：

The new SystemC standard replaces sc_string with std::string, sc_pvector with   std::vector, and sc_exception with std::exception. The old nonstandard classes are now deprecated. By default, the name sc_string is undefined, but the old sc_string class is still part of the source code under the name of sc_string_old. All new SystemC applications should use std::string exclusively. These changes will render obsolete code that uses the old classes.

最后用std::string替换sc_string 问题解决。

2.sc_signal的问题。

error C2679: 二进制“<<”: 没有找到接受“const packet_type”类型的右操作数的运算符(或没有可接受的转换)

template <class T>inlinevoidsc_signal<T>::print( ::std::ostream& os ) const{ os << m_cur_val;}

原因是代码中定义了一个信号如下：

sc_signal<packet_type> PACKET;

可能是2.2中sc_signal多了print这个方法导致找不到操作符<<。

在packet_type中重载operator <<问题解决。

struct packet_type {inline bool operator == (const packet_type& rhs) const{return (rhs.info == info && rhs.seq == seq && rhs.retry == retry);}long info;int seq;int retry;};externvoid sc_trace(sc_trace_file *tf, const packet_type& v, const std::string& NAME);inline ostream& operator << (ostream& out, const packet_type& chs){return out<<"seq:"<<chs.seq<<"/tinfo:"<<chs.info<<"/tretry:"<<chs.retry;}

感觉应该有更好的解决方法，SystemC不能让所有只要加到sc_signal上的用户自定义类型都要重载<<吧。

3. sc_signal多信号驱动问题

Error: (E115) sc_signal<T> cannot have more than one driver。

 

查了一下2.2的release notes 有如下说明:

The check for multiple writers of a signal now defaults on rather than
    off. This means that if two separate processes write to a signal an 
    error will be reported. To turn off the check, reverting to the
    behavior of previous releases, one needs set an environment variable:
        setenv SC_SIGNAL_WRITE_CHECK DISABLE
    When set SystemC programs will not perform the write check.

SC_SIGNAL_WRITE_CHECK现在默认是开启的。
systemC中有如下代码
 // CHECK FOR ENVIRONMENT VARIABLES THAT MODIFY SIMULATOR EXECUTION:const char* write_check = std::getenv("SC_SIGNAL_WRITE_CHECK");m_write_check = ( (write_check==0) || strcmp(write_check,"DISABLE") ) ?      true : false; 
这个问题只要设定环境变量把SC_SIGNAL_WRITE_CHECK关掉就行了。