Merge pull request #486 from michael-schaller/dir-cleanup

[Go] Cleanup of obsolete 'callback' and 'extend' examples.
This commit is contained in:
Ian Lance Taylor 2015-08-05 06:49:53 -07:00
commit 5e88857760
14 changed files with 3 additions and 376 deletions

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@ -1,16 +0,0 @@
TOP = ../..
SWIG = $(TOP)/../preinst-swig
CXXSRCS = callback.cxx
TARGET = example
INTERFACE = example.i
SWIGOPT =
check: build
$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' CXXSRCS='$(CXXSRCS)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' go_run
build:
$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' CXXSRCS='$(CXXSRCS)' SWIG='$(SWIG)' \
SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' go_cpp
clean:
$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' INTERFACE='$(INTERFACE)' go_clean

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@ -1,4 +0,0 @@
/* File : example.cxx */
#include "example.h"

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@ -1,23 +0,0 @@
/* File : example.h */
#include <cstdio>
#include <iostream>
class Callback {
public:
virtual ~Callback() { std::cout << "Callback::~Callback()" << std:: endl; }
virtual void run() { std::cout << "Callback::run()" << std::endl; }
};
class Caller {
private:
Callback *_callback;
public:
Caller(): _callback(0) {}
~Caller() { delCallback(); }
void delCallback() { delete _callback; _callback = 0; }
void setCallback(Callback *cb) { delCallback(); _callback = cb; }
void call() { if (_callback) _callback->run(); }
};

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@ -1,11 +0,0 @@
/* File : example.i */
%module(directors="1") example
%{
#include "example.h"
%}
/* turn on director wrapping Callback */
%feature("director") Callback;
%include "example.h"

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@ -1,81 +0,0 @@
<html>
<head>
<title>SWIG:Examples:go:callback</title>
</head>
<body bgcolor="#ffffff">
<tt>SWIG/Examples/go/callback/</tt>
<hr>
<H2>Implementing C++ callbacks in Go</H2>
<p>
This example illustrates how to use directors to implement C++
callbacks in Go.
</p>
<p>
Because Go and C++ use inheritance differently, you must call a
different function to create a class which uses callbacks. Instead of
calling the usual constructor function whose name is <tt>New</tt>
followed by the capitalized name of the class, you call a function
named <tt>NewDirector</tt> followed by the capitalized name of the
class.
</p>
<p>
The first argument to the <tt>NewDirector</tt> function is an instance
of a type. The <tt>NewDirector</tt> function will return an interface
value as usual. However, when calling any method on the returned
value, the program will first check whether the value passed
to <tt>NewDirector</tt> implements that method. If it does, the
method will be called in Go. This is true whether the method is
called from Go code or C++ code.
</p>
<p>
Note that the Go code will be called with just the Go value, not the
C++ value. If the Go code needs to call a C++ method on itself, you
need to get a copy of the C++ object. This is typically done as
follows:
<blockquote>
<pre>
type Child struct { abi Parent }
func (p *Child) ChildMethod() {
p.abi.ParentMethod()
}
func f() {
p := &Child{nil}
d := NewDirectorParent(p)
p.abi = d
...
}
</pre>
</blockquote>
In other words, we first create the Go value. We pass that to
the <tt>NewDirector</tt> function to create the C++ value; this C++
value will be created with an association to the Go value. We then
store the C++ value in the Go value, giving us the reverse
association. That permits us to call parent methods from the child.
</p>
<p>
To delete a director object, use the function <tt>DeleteDirector</tt>
followed by the capitalized name of the class.
</p>
<p>
<ul>
<li><a href="example.h">example.h</a>. Header file containing some enums.
<li><a href="example.i">example.i</a>. Interface file.
<li><a href="runme.go">runme.go</a>. Sample Go program.
</ul>
<hr>
</body>
</html>

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@ -1,41 +0,0 @@
package main
import (
. "./example"
"fmt"
)
func main() {
fmt.Println("Adding and calling a normal C++ callback")
fmt.Println("----------------------------------------")
caller := NewCaller()
callback := NewCallback()
caller.SetCallback(callback)
caller.Call()
caller.DelCallback()
callback = NewDirectorCallback(new(GoCallback))
fmt.Println()
fmt.Println("Adding and calling a Go callback")
fmt.Println("------------------------------------")
caller.SetCallback(callback)
caller.Call()
caller.DelCallback()
// Test that a double delete does not occur as the object has
// already been deleted from the C++ layer.
DeleteDirectorCallback(callback)
fmt.Println()
fmt.Println("Go exit")
}
type GoCallback struct{}
func (p *GoCallback) Run() {
fmt.Println("GoCallback.Run")
}

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@ -1,10 +1,8 @@
# see top-level Makefile.in
callback
class
constants
director
enum
extend
funcptr
multimap
pointer

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@ -1,16 +0,0 @@
TOP = ../..
SWIG = $(TOP)/../preinst-swig
CXXSRCS = extend.cxx
TARGET = example
INTERFACE = example.i
SWIGOPT =
check: build
$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' CXXSRCS='$(CXXSRCS)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' go_run
build:
$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' CXXSRCS='$(CXXSRCS)' SWIG='$(SWIG)' \
SWIGOPT='$(SWIGOPT)' TARGET='$(TARGET)' INTERFACE='$(INTERFACE)' go_cpp
clean:
$(MAKE) -f $(TOP)/Makefile SRCDIR='$(SRCDIR)' INTERFACE='$(INTERFACE)' go_clean

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@ -1,56 +0,0 @@
/* File : example.h */
#include <cstdio>
#include <iostream>
#include <vector>
#include <string>
#include <cmath>
class Employee {
private:
std::string name;
public:
Employee(const char* n): name(n) {}
virtual std::string getTitle() { return getPosition() + " " + getName(); }
virtual std::string getName() { return name; }
virtual std::string getPosition() const { return "Employee"; }
virtual ~Employee() { printf("~Employee() @ %p\n", (void *)this); }
};
class Manager: public Employee {
public:
Manager(const char* n): Employee(n) {}
virtual std::string getPosition() const { return "Manager"; }
};
class EmployeeList {
std::vector<Employee*> list;
public:
EmployeeList() {
list.push_back(new Employee("Bob"));
list.push_back(new Employee("Jane"));
list.push_back(new Manager("Ted"));
}
void addEmployee(Employee *p) {
list.push_back(p);
std::cout << "New employee added. Current employees are:" << std::endl;
std::vector<Employee*>::iterator i;
for (i=list.begin(); i!=list.end(); i++) {
std::cout << " " << (*i)->getTitle() << std::endl;
}
}
const Employee *get_item(int i) {
return list[i];
}
~EmployeeList() {
std::vector<Employee*>::iterator i;
std::cout << "~EmployeeList, deleting " << list.size() << " employees." << std::endl;
for (i=list.begin(); i!=list.end(); i++) {
delete *i;
}
std::cout << "~EmployeeList empty." << std::endl;
}
};

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@ -1,15 +0,0 @@
/* File : example.i */
%module(directors="1") example
%{
#include "example.h"
%}
%include "std_vector.i"
%include "std_string.i"
/* turn on director wrapping for Manager */
%feature("director") Employee;
%feature("director") Manager;
%include "example.h"

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@ -1,4 +0,0 @@
/* File : example.cxx */
#include "example.h"

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@ -1,27 +0,0 @@
<html>
<head>
<title>SWIG:Examples:go:extend</title>
</head>
<body bgcolor="#ffffff">
<tt>SWIG/Examples/go/extend/</tt>
<hr>
<H2>Extending a simple C++ class in Go</H2>
<p>
This example illustrates the extending of a C++ class with cross
language polymorphism.
<p>
<ul>
<li><a href="example.h">example.h</a>. Header file containing some enums.
<li><a href="example.i">example.i</a>. Interface file.
<li><a href="runme.go">runme.go</a>. Sample Go program.
</ul>
<hr>
</body>
</html>

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@ -1,76 +0,0 @@
// This file illustrates the cross language polymorphism using directors.
package main
import (
. "./example"
"fmt"
)
type CEO struct{}
func (p *CEO) GetPosition() string {
return "CEO"
}
func main() {
// Create an instance of CEO, a class derived from the Go
// proxy of the underlying C++ class. The calls to getName()
// and getPosition() are standard, the call to getTitle() uses
// the director wrappers to call CEO.getPosition().
e := NewDirectorManager(new(CEO), "Alice")
fmt.Println(e.GetName(), " is a ", e.GetPosition())
fmt.Println("Just call her \"", e.GetTitle(), "\"")
fmt.Println("----------------------")
// Create a new EmployeeList instance. This class does not
// have a C++ director wrapper, but can be used freely with
// other classes that do.
list := NewEmployeeList()
// EmployeeList owns its items, so we must surrender ownership
// of objects we add.
// e.DisownMemory()
list.AddEmployee(e)
fmt.Println("----------------------")
// Now we access the first four items in list (three are C++
// objects that EmployeeList's constructor adds, the last is
// our CEO). The virtual methods of all these instances are
// treated the same. For items 0, 1, and 2, all methods
// resolve in C++. For item 3, our CEO, GetTitle calls
// GetPosition which resolves in Go. The call to GetPosition
// is slightly different, however, because of the overridden
// GetPosition() call, since now the object reference has been
// "laundered" by passing through EmployeeList as an
// Employee*. Previously, Go resolved the call immediately in
// CEO, but now Go thinks the object is an instance of class
// Employee. So the call passes through the Employee proxy
// class and on to the C wrappers and C++ director, eventually
// ending up back at the Java CEO implementation of
// getPosition(). The call to GetTitle() for item 3 runs the
// C++ Employee::getTitle() method, which in turn calls
// GetPosition(). This virtual method call passes down
// through the C++ director class to the Java implementation
// in CEO. All this routing takes place transparently.
fmt.Println("(position, title) for items 0-3:")
fmt.Println(" ", list.Get_item(0).GetPosition(), ", \"", list.Get_item(0).GetTitle(), "\"")
fmt.Println(" ", list.Get_item(1).GetPosition(), ", \"", list.Get_item(1).GetTitle(), "\"")
fmt.Println(" ", list.Get_item(2).GetPosition(), ", \"", list.Get_item(2).GetTitle(), "\"")
fmt.Println(" ", list.Get_item(3).GetPosition(), ", \"", list.Get_item(3).GetTitle(), "\"")
fmt.Println("----------------------")
// Time to delete the EmployeeList, which will delete all the
// Employee* items it contains. The last item is our CEO,
// which gets destroyed as well.
DeleteEmployeeList(list)
fmt.Println("----------------------")
// All done.
fmt.Println("Go exit")
}

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@ -21,8 +21,7 @@ certain C declarations are turned into constants.
<li><a href="pointer/index.html">pointer</a>. Simple pointer handling.
<li><a href="funcptr/index.html">funcptr</a>. Pointers to functions.
<li><a href="template/index.html">template</a>. C++ templates.
<li><a href="callback/index.html">callback</a>. C++ callbacks using directors.
<li><a href="extend/index.html">extend</a>. Polymorphism using directors.
<li><a href="director/index.html">director</a>. Example how to utilize the director feature.
</ul>
<h2>Compilation Issues</h2>
@ -46,7 +45,7 @@ the <tt>6g</tt> or <tt>8g</tt> compiler, the steps look like this
<pre>
% swig -go interface.i
% gcc -fpic -c interface_wrap.c
% gcc -shared interface_wrap.o $(OBJS) -o interfacemodule.so
% gcc -shared interface_wrap.o $(OBJS) -o interfacemodule.so
% 6g interface.go
% 6c interface_gc.c
% gopack grc interface.a interface.6 interface_gc.6
@ -83,7 +82,7 @@ All of the examples were last tested with the following configuration
<li>gcc-4.2.4
</ul>
Your mileage may vary. If you experience a problem, please let us know by
Your mileage may vary. If you experience a problem, please let us know by
contacting us on the <a href="http://www.swig.org/mail.html">mailing lists</a>.
</body>
</html>