From c1d3b45735eb633360b954eb2c3779efd73d956a Mon Sep 17 00:00:00 2001
From: Sebastien Binet <binet@cern.ch>
Date: Fri, 14 Aug 2015 13:02:17 +0200
Subject: [PATCH] bind: first stab at a gopy object model

---
 _examples/pointers/pointers.go | 19 +++++++++++++------
 bind/gencpy.go                 | 25 +++++++++++++++++++++++++
 bind/gencpy_struct.go          |  1 +
 bind/gencpy_type.go            |  2 ++
 bind/gengo.go                  | 34 ++++++++++++++++++++++++++++++++++
 5 files changed, 75 insertions(+), 6 deletions(-)

diff --git a/_examples/pointers/pointers.go b/_examples/pointers/pointers.go
index fd3ded1..9f9c731 100644
--- a/_examples/pointers/pointers.go
+++ b/_examples/pointers/pointers.go
@@ -4,18 +4,25 @@
 
 package pointers
 
-import (
-	"github.com/go-python/gopy/_examples/cpkg"
-)
-
 //type SPtr *S
+
 type S struct {
 	Value int
 }
 
 // Inc increments the value of s
 func Inc(s *S) {
-	cpkg.Printf("==> go: s.Value==%d\n", s.Value)
 	s.Value++
-	cpkg.Printf("<== go: s.Value==%d\n", s.Value)
+}
+
+type MyInt int
+
+// IncInt increments an integer
+func IncMyInt(i *MyInt) {
+	(*i)++
+}
+
+// IncInt increments an integer
+func IncInt(i *int) {
+	(*i)++
 }
diff --git a/bind/gencpy.go b/bind/gencpy.go
index c76adfa..ce49438 100644
--- a/bind/gencpy.go
+++ b/bind/gencpy.go
@@ -29,6 +29,31 @@ const (
 // header exported from 'go tool cgo'
 #include "%[3]s.h"
 
+#if PY_VERSION_HEX > 0x03000000
+#error "Python-3 is not yet supported by gopy"
+#endif
+
+
+// --- gopy object model ---
+
+struct _gopy_object;
+
+// empty interface converter
+typedef GoInterface (*gopy_efacefunc)(struct _gopy_object *);
+
+
+// proxy for all go values
+struct _gopy_object {
+	PyObject_HEAD
+	void *go; /* handle to address of go value */
+	gopy_efacefunc eface;
+};
+
+typedef struct _gopy_object gopy_object;
+
+// --- gopy object model ---
+
+
 // helpers for cgopy
 
 #define def_cnv(name, c2py, py2c, gotype) \
diff --git a/bind/gencpy_struct.go b/bind/gencpy_struct.go
index 88d582f..c35016c 100644
--- a/bind/gencpy_struct.go
+++ b/bind/gencpy_struct.go
@@ -25,6 +25,7 @@ func (g *cpyGen) genStruct(cpy Struct) {
 		cpy.sym.cgoname,
 		cpy.ID(),
 	)
+	g.decl.Printf("gopy_efacefunc eface;\n")
 	g.decl.Outdent()
 	g.decl.Printf("} %s;\n", cpy.sym.cpyname)
 	g.decl.Printf("\n\n")
diff --git a/bind/gencpy_type.go b/bind/gencpy_type.go
index 3f4af4e..1eddc87 100644
--- a/bind/gencpy_type.go
+++ b/bind/gencpy_type.go
@@ -45,6 +45,7 @@ func (g *cpyGen) genType(sym *symbol) {
 			sym.id,
 		)
 	}
+	g.decl.Printf("gopy_efacefunc eface;\n")
 	g.decl.Outdent()
 	g.decl.Printf("} %s;\n", sym.cpyname)
 	g.decl.Printf("\n\n")
@@ -152,6 +153,7 @@ func (g *cpyGen) genTypeNew(sym *symbol) {
 	g.impl.Printf("%s *self;\n", sym.cpyname)
 	g.impl.Printf("self = (%s *)type->tp_alloc(type, 0);\n", sym.cpyname)
 	g.impl.Printf("self->cgopy = cgo_func_%s_new();\n", sym.id)
+	g.impl.Printf("self->eface = (gopy_efacefunc)cgo_func_%s_eface;\n", sym.id)
 	g.impl.Printf("return (PyObject*)self;\n")
 	g.impl.Outdent()
 	g.impl.Printf("}\n\n")
diff --git a/bind/gengo.go b/bind/gengo.go
index 18e7fd7..a9a8ca1 100644
--- a/bind/gengo.go
+++ b/bind/gengo.go
@@ -360,6 +360,23 @@ func (g *goGen) genStruct(s Struct) {
 	g.Outdent()
 	g.Printf("}\n\n")
 
+	// empty interface converter
+	g.Printf("//export cgo_func_%[1]s_eface\n", s.ID())
+	g.Printf("func cgo_func_%[1]s_eface(self %[2]s) interface{} {\n",
+		s.sym.id,
+		s.sym.cgoname,
+	)
+	g.Indent()
+	g.Printf("var v interface{} = ")
+	if s.sym.isBasic() {
+		g.Printf("%[1]s(self)\n", s.sym.gofmt())
+	} else {
+		g.Printf("*(*%[1]s)(unsafe.Pointer(self))\n", s.sym.gofmt())
+	}
+	g.Printf("return v\n")
+	g.Outdent()
+	g.Printf("}\n\n")
+
 	// support for __str__
 	g.Printf("//export cgo_func_%[1]s_str\n", s.ID())
 	g.Printf(
@@ -537,6 +554,23 @@ func (g *goGen) genType(sym *symbol) {
 	g.Outdent()
 	g.Printf("}\n\n")
 
+	// empty interface converter
+	g.Printf("//export cgo_func_%[1]s_eface\n", sym.id)
+	g.Printf("func cgo_func_%[1]s_eface(self %[2]s) interface{} {\n",
+		sym.id,
+		sym.cgoname,
+	)
+	g.Indent()
+	g.Printf("var v interface{} = ")
+	if sym.isBasic() {
+		g.Printf("%[1]s(self)\n", sym.gofmt())
+	} else {
+		g.Printf("*(*%[1]s)(unsafe.Pointer(self))\n", sym.gofmt())
+	}
+	g.Printf("return v\n")
+	g.Outdent()
+	g.Printf("}\n\n")
+
 	// support for __str__
 	g.Printf("//export cgo_func_%[1]s_str\n", sym.id)
 	g.Printf(