genbindings: wip

.gitignore

@@ -1,5 +1,6 @@
 # scratch files
 *.json
+gen_*
 
 # binaries
 miqt

cmd/genbindings/clang2il.go

@@ -3,6 +3,8 @@ package main
 import (
 	"errors"
 	"fmt"
+	"log"
+	"strings"
 )
 
 func parseHeader(inner []interface{}) (*parsedHeader, error) {
@@ -42,7 +44,7 @@ func parseHeader(inner []interface{}) (*parsedHeader, error) {
 
 			fmt.Printf("-> %q name=%q\n", kind, nodename)
 			if classInner, ok := node["inner"].([]interface{}); ok {
-				obj, err := processType(classInner)
+				obj, err := processType(classInner, nodename)
 				if err != nil {
 					panic(err)
 				}
@@ -61,9 +63,11 @@ func parseHeader(inner []interface{}) (*parsedHeader, error) {
 	return &ret, nil // done
 }
 
-func processType(inner []interface{}) (nativeClass, error) {
+func processType(inner []interface{}, className string) (nativeClass, error) {
 	var ret nativeClass
+	ret.className = className
 
+nextMethod:
 	for _, node := range inner {
 		node, ok := node.(map[string]interface{})
 		if !ok {
@@ -76,8 +80,69 @@ func processType(inner []interface{}) (nativeClass, error) {
 		}
 
 		switch kind {
+		case "CXXMethodDecl":
+			// Method
+			methodName, ok := node["name"].(string)
+			if !ok {
+				return nativeClass{}, errors.New("method has no name")
+			}
+
+			var mm nativeMethod
+			mm.methodName = methodName
+
+			if typobj, ok := node["type"].(map[string]interface{}); ok {
+				if qualType, ok := typobj["qualType"].(string); ok {
+					// The qualType is the whole type of the method, including its parameter types
+					// If anything here is too complicated, skip the whole method
+					if strings.Contains(qualType, `::`) {
+						log.Printf("Skipping method %q with complex type %q", mm.methodName, qualType)
+						continue nextMethod
+					}
+
+					// We only want up to the first ( character
+					mm.returnType, _, _ = strings.Cut(qualType, `(`)
+					mm.returnType = strings.TrimSpace(mm.returnType)
+				}
+			}
+
+			if methodInner, ok := node["inner"].([]interface{}); ok {
+				for _, methodObj := range methodInner {
+					methodObj, ok := methodObj.(map[string]interface{})
+					if !ok {
+						return nativeClass{}, errors.New("inner[] element not an object")
+					}
+
+					switch methodObj["kind"] {
+					case "ParmVarDecl":
+						// Parameter variable
+						parmName, _ := methodObj["name"].(string) // n.b. may be unnamed
+						if parmName == "" {
+							parmName = fmt.Sprintf("param%d", len(mm.parameters)+1)
+						}
+
+						var parmType string
+						if typobj, ok := node["type"].(map[string]interface{}); ok {
+							if qualType, ok := typobj["qualType"].(string); ok {
+								parmType = qualType
+							}
+						}
+
+						mm.parameters = append(mm.parameters, nativeParameter{
+							name: parmName,
+							typ:  parmType,
+						})
+
+					default:
+						// Something else inside a declaration??
+						fmt.Printf("==> NOT IMPLEMENTED CXXMethodDecl->%q\n", kind)
+					}
+				}
+			}
+
+			ret.methods = append(ret.methods, mm)
+
 		default:
-			fmt.Printf("==> %q\n", kind)
+			fmt.Printf("==> NOT IMPLEMENTED %q\n", kind)
 		}
 	}
 

cmd/genbindings/emitgo.go

@@ -1,9 +1,86 @@
 package main
 
 import (
-	"errors"
+	"fmt"
+	"strings"
 )
 
-func emitGo(src *parsedHeader) (string, error) {
-	return "", errors.New("TODO")
+func emitParametersCpp(params []nativeParameter) string {
+	tmp := make([]string, 0, len(params))
+	for _, p := range params {
+		tmp = append(tmp, p.name+" "+p.typ)
+	}
+	return strings.Join(tmp, ", ")
+}
+
+func emitParametersGo(params []nativeParameter) string {
+	tmp := make([]string, 0, len(params))
+	for _, p := range params {
+		tmp = append(tmp, p.typ+" "+p.name)
+	}
+	return strings.Join(tmp, ", ")
+}
+
+func emitBindingHeader(src *parsedHeader, filename string) (string, error) {
+	ret := strings.Builder{}
+
+	includeGuard := strings.ToUpper(strings.Replace(filename, `.`, `_`, -1)) + "_H"
+
+	ret.WriteString(`#ifndef ` + includeGuard + `
+#define ` + includeGuard + `
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+`)
+
+	for _, c := range src.classes {
+		ret.WriteString(`typedef void* P` + c.className + ";\n\n")
+
+		for i, ctor := range c.ctors {
+			suffix := ""
+			if i > 0 {
+				suffix = fmt.Sprintf("%d", i+1)
+			}
+			// TODO fixup parameters
+			ret.WriteString(fmt.Sprintf("P%s %s_new%s(%s);\n", c.className, suffix, emitParametersCpp(ctor.parameters)))
+		}
+
+		for _, m := range c.methods {
+			ret.WriteString(fmt.Sprintf("%s %s_%s(%s);\n", m.returnType, c.className, m.methodName, emitParametersCpp(m.parameters)))
+		}
+
+		ret.WriteString("\n")
+	}
+
+	ret.WriteString(`
+
+#ifdef __cplusplus
+} /* extern C */
+#endif 
+
+#endif
+`)
+	return ret.String(), nil
+}
+
+func emitBindingCpp(src *parsedHeader) (string, error) {
+	ret := strings.Builder{}
+	return ret.String(), nil
+}
+
+func emitGo(src *parsedHeader) (string, error) {
+
+	ret := strings.Builder{}
+	ret.WriteString("package miqt\n\n")
+
+	// CGO block
+
+	// Pure-Go block
+	for _, c := range src.classes {
+		_ = c
+	}
+
+	return ret.String(), nil
 }

cmd/genbindings/intermediate.go

@@ -1,5 +1,10 @@
 package main
 
+type nativeParameter struct {
+	name string
+	typ  string
+}
+
 type nativeProperty struct {
 	propertyName string
 	propertyType string
@@ -9,11 +14,12 @@ type nativeProperty struct {
 type nativeMethod struct {
 	methodName string
 	returnType string
-	parameters []string
+	parameters []nativeParameter
 }
 
 type nativeClass struct {
 	className string
+	ctors     []nativeMethod // only use the parameters
 	extends   []string
 	methods   []nativeMethod
 	props     []nativeProperty

cmd/genbindings/main.go

@@ -3,8 +3,9 @@ package main
 import (
 	"context"
 	"flag"
-	"fmt"
+	"io/ioutil"
 	"log"
+	"path/filepath"
 	"strings"
 )
 
@@ -14,6 +15,7 @@ func main() {
 	clang := flag.String("clang", "clang", "Custom path to clang")
 	inputHeader := flag.String("inputHeader", `/usr/include/x86_64-linux-gnu/qt5/QtWidgets/qpushbutton.h`, "Input file")
 	cflags := flag.String("cflags", `-DQT_WIDGETS_LIB -I/usr/include/x86_64-linux-gnu/qt5/QtWidgets -I/usr/include/x86_64-linux-gnu/qt5 -I/usr/include/x86_64-linux-gnu/qt5/QtCore -DQT_GUI_LIB -I/usr/include/x86_64-linux-gnu/qt5/QtGui -DQT_CORE_LIB`, "Cflags to pass to clang (e.g. `pkg-config --cflags Qt5Widgets`)")
+	outDir := flag.String("outdir", "..", "Output directory for generated gen_** files")
 
 	flag.Parse()
 
@@ -29,13 +31,40 @@ func main() {
 		panic(err)
 	}
 
-	// Emit Go code from the intermediate format
+	// Emit 3 code files from the intermediate format
+	outputName := filepath.Join(*outDir, "gen_"+strings.TrimSuffix(filepath.Base(*inputHeader), `.h`))
+
 	goSrc, err := emitGo(parsed)
 	if err != nil {
 		panic(err)
 	}
 
-	fmt.Println(goSrc)
+	err = ioutil.WriteFile(outputName+".go", []byte(goSrc), 0644)
+	if err != nil {
+		panic(err)
+	}
 
-	log.Printf("Processing %q completed", inputHeader)
+	bindingCppSrc, err := emitBindingCpp(parsed)
+	if err != nil {
+		panic(err)
+	}
+
+	err = ioutil.WriteFile(outputName+".cpp", []byte(bindingCppSrc), 0644)
+	if err != nil {
+		panic(err)
+	}
+
+	bindingHSrc, err := emitBindingHeader(parsed, filepath.Base(*inputHeader))
+	if err != nil {
+		panic(err)
+	}
+
+	err = ioutil.WriteFile(outputName+".h", []byte(bindingHSrc), 0644)
+	if err != nil {
+		panic(err)
+	}
+
+	// Done
+
+	log.Printf("Processing %q completed", *inputHeader)
 }