bind/{cpy,cffi}: attached doc of Go vars if available

This CL adds the doc-string of Go variables (if available) to the python
getter and setter functions, for both CPython2 and CFFI.

Update TestBindVars accordingly.

Author: sbinet

_examples/vars/test.py

@@ -47,3 +47,7 @@
 
 print("k1 = %s" % vars.GetKind1())
 print("k2 = %s" % vars.GetKind2())
+
+print("vars.GetDoc() = %s" % repr(vars.GetDoc()))
+print("doc of vars.GetDoc = %s" % (repr(vars.GetDoc.__doc__),))
+print("doc of vars.SetDoc = %s" % (repr(vars.SetDoc.__doc__),))

_examples/vars/vars.go

@@ -24,6 +24,9 @@ var (
 	Kind2      = 2
 )
 
+// Doc is a top-level string with some documentation attached.
+var Doc = "A variable with some documentation"
+
 // FIXME: also use an unexported type
 // type kind int
 // var (

bind/gencffi.go

@@ -290,6 +290,14 @@ func (g *cffiGen) genConst(c Const) {
 
 func (g *cffiGen) genVar(v Var) {
 	id := g.pkg.Name() + "_" + v.Name()
+	get := "returns " + g.pkg.Name() + "." + v.Name()
+	set := "sets " + g.pkg.Name() + "." + v.Name()
+	if v.doc != "" {
+		// if the Go variable had some documentation attached,
+		// put it there as well.
+		get += "\n\n" + v.doc
+		set += "\n\n" + v.doc
+	}
 	doc := v.doc
 	{
 		res := []*Var{newVar(g.pkg, v.GoType(), "ret", v.Name(), doc)}
@@ -300,7 +308,7 @@ func (g *cffiGen) genVar(v Var) {
 			typ:  nil,
 			name: v.Name(),
 			id:   id + "_get",
-			doc:  "returns " + g.pkg.Name() + "." + v.Name(),
+			doc:  get,
 			ret:  v.GoType(),
 			err:  false,
 		}
@@ -315,7 +323,7 @@ func (g *cffiGen) genVar(v Var) {
 			typ:  nil,
 			name: v.Name(),
 			id:   id + "_set",
-			doc:  "sets " + g.pkg.Name() + "." + v.Name(),
+			doc:  set,
 			ret:  nil,
 			err:  false,
 		}

bind/gencpy.go

@@ -243,11 +243,13 @@ func (g *cpyGen) gen() error {
 
 	for _, v := range g.pkg.vars {
 		name := v.Name()
-		get := v.doc
-		set := v.doc
-		if v.doc == "" {
-			get = "returns " + g.pkg.Name() + "." + name
-			set = "sets " + g.pkg.Name() + "." + name
+		get := "returns " + g.pkg.Name() + "." + name
+		set := "sets " + g.pkg.Name() + "." + name
+		if v.doc != "" {
+			// if the Go variable had some documentation attached,
+			// put it there as well.
+			get += "\n\n" + v.doc
+			set += "\n\n" + v.doc
 		}
 		g.impl.Printf("{%[1]q, %[2]s, METH_VARARGS, %[3]q},\n",
 			"Get"+name, "cpy_func_"+v.id+"_get", get,
@@ -322,7 +324,7 @@ func (g *cpyGen) genVar(v Var) {
 			typ:  nil,
 			name: v.Name(),
 			id:   id + "_get",
-			doc:  "returns " + g.pkg.Name() + "." + v.Name(),
+			doc:  "", // ignored: done during cpyGen.gen()
 			ret:  v.GoType(),
 			err:  false,
 		}
@@ -337,7 +339,7 @@ func (g *cpyGen) genVar(v Var) {
 			typ:  nil,
 			name: v.Name(),
 			id:   id + "_set",
-			doc:  "sets " + g.pkg.Name() + "." + v.Name(),
+			doc:  "", // ignored: done during cpyGen.gen()
 			ret:  nil,
 			err:  false,
 		}

main_test.go

@@ -805,6 +805,9 @@ v6 = 50
 v7 = 1111.1111
 k1 = 123
 k2 = 456
+vars.GetDoc() = 'A variable with some documentation'
+doc of vars.GetDoc = 'returns vars.Doc\n\nDoc is a top-level string with some documentation attached.\n'
+doc of vars.SetDoc = 'sets vars.Doc\n\nDoc is a top-level string with some documentation attached.\n'
 `),
 	})
 
@@ -836,6 +839,9 @@ v6 = 50
 v7 = 1111.1111
 k1 = 123
 k2 = 456
+vars.GetDoc() = 'A variable with some documentation'
+doc of vars.GetDoc = 'returns vars.Doc\n\nDoc is a top-level string with some documentation attached.\n'
+doc of vars.SetDoc = 'sets vars.Doc\n\nDoc is a top-level string with some documentation attached.\n'
 `),
 	})
 }