From afcde0a69b921df9596edb834749cab94554e708 Mon Sep 17 00:00:00 2001
From: mappu <mappu04@gmail.com>
Date: Sat, 10 Aug 2024 12:54:26 +1200
Subject: [PATCH] genbindings: inheritance support

---
 cmd/genbindings/clang2il.go     | 20 ++++++++++++++++++++
 cmd/genbindings/emitgo.go       | 15 ++++++++++++++-
 cmd/genbindings/intermediate.go |  2 +-
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/cmd/genbindings/clang2il.go b/cmd/genbindings/clang2il.go
index 1f1eab1d..0baa9422 100644
--- a/cmd/genbindings/clang2il.go
+++ b/cmd/genbindings/clang2il.go
@@ -76,6 +76,26 @@ func processClassType(node map[string]interface{}, className string) (CppClass,
 		}
 	}
 
+	// Check if this (publicly) inherits another class
+	if bases, ok := node["bases"].([]interface{}); ok {
+		for _, base := range bases {
+			base, ok := base.(map[string]interface{})
+			if !ok {
+				continue
+			}
+
+			access, ok := base["access"].(string)
+			if !(ok && access == "public") {
+				continue
+			}
+
+			if typ, ok := base["type"].(map[string]interface{}); ok {
+				if qualType, ok := typ["qualType"].(string); ok {
+					ret.Inherits = append(ret.Inherits, qualType)
+				}
+			}
+		}
+	}
 
 	// Parse all methods
 
diff --git a/cmd/genbindings/emitgo.go b/cmd/genbindings/emitgo.go
index ee4f26cb..be424319 100644
--- a/cmd/genbindings/emitgo.go
+++ b/cmd/genbindings/emitgo.go
@@ -93,6 +93,14 @@ import "C"
 		ret.WriteString(`
 		type ` + c.ClassName + ` struct {
 			h C.P` + c.ClassName + `
+		`)
+
+		// Embed all inherited types to directly allow calling inherited methods
+		for _, base := range c.Inherits {
+			ret.WriteString(base + "\n")
+		}
+
+		ret.WriteString(`
 		}
 		
 		func (this *` + c.ClassName + `) cPointer() C.P` + c.ClassName + ` {
@@ -104,13 +112,18 @@ import "C"
 		
 		`)
 
+		localInit := "h: ret"
+		for _, base := range c.Inherits {
+			localInit += ", " + base + ": " + base + "{h: ret}"
+		}
+
 		for i, ctor := range c.Ctors {
 			preamble, forwarding := emitParametersGo2CABIForwarding(ctor)
 			ret.WriteString(`
 			// New` + c.ClassName + maybeSuffix(i) + ` constructs a new ` + c.ClassName + ` object.
 			func New` + c.ClassName + maybeSuffix(i) + `(` + emitParametersGo(ctor.Parameters) + `) {
 				` + preamble + ` ret := C.` + c.ClassName + `_new` + maybeSuffix(i) + `(` + forwarding + `)
-				return &` + c.ClassName + `{h: ret}
+				return &` + c.ClassName + `{` + localInit + `}
 			}
 			
 			`)
diff --git a/cmd/genbindings/intermediate.go b/cmd/genbindings/intermediate.go
index 77778e2f..1ac2adcd 100644
--- a/cmd/genbindings/intermediate.go
+++ b/cmd/genbindings/intermediate.go
@@ -71,7 +71,7 @@ type CppClass struct {
 	ClassName string
 	Abstract  bool
 	Ctors     []CppMethod // only use the parameters
-	Extends   []string
+	Inherits  []string    // other class names
 	Methods   []CppMethod
 	Props     []CppProperty
 }