define.cc

一个mips虚拟机非常好代码,使用C++来编写的,希望大家多学学,

#include <limits.h>
#include <string.h>
#include <tcl.h>
#include "assert.hh"
#include "error.hh"
#include "module.hh"
#include "simarg.hh"
#include "sulima.hh"


// BasicModule constructor.
BasicModule::BasicModule(const char *name)
    : name_str(copy(name))
{
    // Create the Tcl namespace.
    char *script = copy("namespace eval sim::", name, " { }", 0);
    int rc = Tcl_GlobalEval(sulima_tcl, script);
    delete script;
    if (rc != TCL_OK)
	throw ScriptError();
}


// BasicModule destructor.
BasicModule::~BasicModule()
{
    delete name_str;
}


// Define a Tcl variable.

static void
define(const char *ns, const char *name, void *addr, int type, bool ro)
{
    if (ro)
	type |= TCL_LINK_READ_ONLY;
    char *full_name = !strcmp(ns, "Sulima") ?
	copy("::sim::", name, 0) : copy("::sim::", ns, "::", name, 0);
    int rc = Tcl_LinkVar(sulima_tcl, full_name, (char *)addr, type);
    delete full_name;
    if (rc != TCL_OK)
	throw ScriptError();
}

void
BasicModule::define(const char *nm, int &var, int init, bool ro)
{
    var = init;
    ::define(name(), nm, &var, TCL_LINK_INT, ro);
}

void
BasicModule::define(const char *nm, char *&var, const char *init, bool ro)
{
    size_t n = strlen(init) + 1;
    var = Tcl_Alloc(n);
    if (!var)
	throw OutOfMemory();
    memcpy(var, init, n);
    try {
	::define(name(), nm, &var, TCL_LINK_STRING, ro);
    }
    catch (...) {
	Tcl_Free(var);
	throw;
    }
}


// Create a new Tcl function from a global C++ function. The user-supplied
// function is enclosed in a simple C wrappers to mould the arguments and
// return values into shape.

struct PlainWrapper {
    SimArg (*fn)(const SimArgs &);
    PlainWrapper(SimArg (*f)(const SimArgs &))
	: fn(f) { }
};

extern "C" {

    static int
    plain_wrapper(PlainWrapper *p,
		  Tcl_Interp *interp, int objc, Tcl_Obj *const objv[])
    {
	try {
	    SimArg ret = p->fn(SimArgs(objc - 1, objv + 1));
	    Tcl_SetObjResult(interp, ret.get_obj());
	    return TCL_OK;
	}
	catch (const Error &e) {
	    Tcl_SetResult(interp, (char *)e.what(), TCL_VOLATILE);
	    return TCL_ERROR;
	}
    }

    static void
    delete_plain_wrapper(PlainWrapper *p)
    {
	delete p;
    }

}

void
BasicModule::define(const char *nm, SimArg (*fn)(const SimArgs &))
{
    PlainWrapper *wrapper = new PlainWrapper(fn);
    char *full_name = !strcmp(name(), "Sulima") ?
	copy("::sim::", nm, 0) : copy("::sim::", name(), "::", nm, 0);
    Tcl_Command rc =
	Tcl_CreateObjCommand(sulima_tcl, full_name,
			     (Tcl_ObjCmdProc *)plain_wrapper,
			     (ClientData)wrapper,
			     (Tcl_CmdDeleteProc *)delete_plain_wrapper);
    delete full_name;
    if (!rc)
	throw ScriptError();
}


// Create a new Tcl function from a C++ member function. The user-supplied
// function is enclosed in a simple C wrappers to mould the arguments and
// return values into shape.

struct MemberWrapper {
    Object *obj;
    SimArg (Object::*fn)(const SimArgs &);
    MemberWrapper(Object *o, SimArg (Object::*f)(const SimArgs &))
	: obj(o), fn(f) { }
};

extern "C" {

    static int
    member_wrapper(MemberWrapper *p,
		   Tcl_Interp *interp, int objc, Tcl_Obj *const objv[])
    {
	try {
	    SimArg ret = ((p->obj)->*(p->fn))(SimArgs(objc - 1, objv + 1));
	    Tcl_SetObjResult(interp, ret.get_obj());
	    return TCL_OK;
	}
	catch (const Error &e) {
	    Tcl_SetResult(interp, (char *)e.what(), TCL_VOLATILE);
	    return TCL_ERROR;
	}
    }

    static void
    delete_member_wrapper(MemberWrapper *p)
    {
	delete p;
    }

}

void
BasicModule::define(const char *nm,
		    Object *obj, SimArg (Object::*fn)(const SimArgs &))
{
    MemberWrapper *wrapper = new MemberWrapper(obj, fn);
    char *full_name = !strcmp(name(), "Sulima") ?
	copy("::sim::", nm, 0) : copy("::sim::", name(), "::", nm, 0);
    Tcl_Command rc =
	Tcl_CreateObjCommand(sulima_tcl, full_name,
			     (Tcl_ObjCmdProc *)member_wrapper,
			     (ClientData)wrapper,
			     (Tcl_CmdDeleteProc *)delete_member_wrapper);
    delete full_name;
    if (!rc) {
	delete wrapper;
	throw ScriptError();
    }
}