feat: generate first raw PipeWire bindings

commit: 768bff5fb26c49e4f2046ba7a053bc1071112054
author: brice · 6mo ago · 2026-04-09 05:23 UTC
parent: 9f72b60
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

9 files · +292 -7

M cmd/pipewiregen/internal/emitter/emitter.go +197 -0

@@ -1,2 +1,199 @@
1	1		// Package emitter renders generated Go source files from the binding model.
2	2		package emitter
	3	+
	4	+	import (
	5	+	"bytes"
	6	+	"fmt"
	7	+	"os"
	8	+	"path/filepath"
	9	+	"strings"
	10	+	"text/template"
	11	+
	12	+	"github.com/bnema/purego-pipewire/cmd/pipewiregen/internal/model"
	13	+	)
	14	+
	15	+	// Emit generates Go source files from the model and writes them to the root directory.
	16	+	// It returns a map of generated file paths to their content.
	17	+	func Emit(m *model.Model, root string) (map[string][]byte, error) {
	18	+	out := make(map[string][]byte)
	19	+	for _, group := range m.Groups {
	20	+	capiPath := filepath.Join("internal", "capi", group.Name+"_gen.go")
	21	+	portPath := filepath.Join("internal", "ports", "out", group.Name+"_gen.go")
	22	+
	23	+	capiContent, err := renderCAPI(group, m.Symbols, m.Libraries)
	24	+	if err != nil {
	25	+	return nil, fmt.Errorf("render capi for group %q: %w", group.Name, err)
	26	+	}
	27	+	out[capiPath] = capiContent
	28	+
	29	+	portContent, err := renderPort(group, m.Symbols)
	30	+	if err != nil {
	31	+	return nil, fmt.Errorf("render port for group %q: %w", group.Name, err)
	32	+	}
	33	+	out[portPath] = portContent
	34	+	}
	35	+	return out, writeAll(root, out)
	36	+	}
	37	+
	38	+	// renderCAPI generates the raw C API function types and registration helpers.
	39	+	func renderCAPI(group model.Group, symbols []model.Symbol, libraries []model.Library) ([]byte, error) {
	40	+	// Find symbols belonging to this group
	41	+	groupSymbols := filterSymbolsByGroup(symbols, group.Name)
	42	+
	43	+	// Build library map for lookup
	44	+	libMap := make(map[string]string)
	45	+	for _, lib := range libraries {
	46	+	libMap[lib.Name] = lib.SOName
	47	+	}
	48	+
	49	+	data := struct {
	50	+	Group model.Group
	51	+	Symbols []model.Symbol
	52	+	LibraryMap map[string]string
	53	+	}{
	54	+	Group: group,
	55	+	Symbols: groupSymbols,
	56	+	LibraryMap: libMap,
	57	+	}
	58	+
	59	+	tmpl, err := template.New("capi").Funcs(template.FuncMap{
	60	+	"title": strings.Title,
	61	+	}).Parse(capiTemplate)
	62	+	if err != nil {
	63	+	return nil, err
	64	+	}
	65	+
	66	+	var buf bytes.Buffer
	67	+	if err := tmpl.Execute(&buf, data); err != nil {
	68	+	return nil, err
	69	+	}
	70	+	return buf.Bytes(), nil
	71	+	}
	72	+
	73	+	// renderPort generates the outbound interface definitions.
	74	+	func renderPort(group model.Group, symbols []model.Symbol) ([]byte, error) {
	75	+	groupSymbols := filterSymbolsByGroup(symbols, group.Name)
	76	+
	77	+	// Convert symbols to methods with proper Go names
	78	+	type Method struct {
	79	+	Name string
	80	+	GoName string
	81	+	Signature string
	82	+	CName string
	83	+	}
	84	+
	85	+	methods := make([]Method, 0, len(groupSymbols))
	86	+	for _, sym := range groupSymbols {
	87	+	methods = append(methods, Method{
	88	+	Name: sym.Name,
	89	+	GoName: toGoName(sym.Name),
	90	+	Signature: sym.Signature,
	91	+	CName: sym.Name,
	92	+	})
	93	+	}
	94	+
	95	+	data := struct {
	96	+	Group model.Group
	97	+	Methods []Method
	98	+	}{
	99	+	Group: group,
	100	+	Methods: methods,
	101	+	}
	102	+
	103	+	tmpl, err := template.New("port").Funcs(template.FuncMap{
	104	+	"title": strings.Title,
	105	+	}).Parse(portTemplate)
	106	+	if err != nil {
	107	+	return nil, err
	108	+	}
	109	+
	110	+	var buf bytes.Buffer
	111	+	if err := tmpl.Execute(&buf, data); err != nil {
	112	+	return nil, err
	113	+	}
	114	+	return buf.Bytes(), nil
	115	+	}
	116	+
	117	+	// filterSymbolsByGroup returns symbols that belong to the given group.
	118	+	func filterSymbolsByGroup(symbols []model.Symbol, groupName string) []model.Symbol {
	119	+	var result []model.Symbol
	120	+	for _, sym := range symbols {
	121	+	if sym.Group == groupName {
	122	+	result = append(result, sym)
	123	+	}
	124	+	}
	125	+	return result
	126	+	}
	127	+
	128	+	// toGoName converts a C function name like pw_init to a Go name like PWInit.
	129	+	func toGoName(cName string) string {
	130	+	// Handle pw_ prefix specially
	131	+	if strings.HasPrefix(cName, "pw_") {
	132	+	name := cName[3:]
	133	+	parts := strings.Split(name, "_")
	134	+	for i, p := range parts {
	135	+	parts[i] = strings.Title(p)
	136	+	}
	137	+	return "PW" + strings.Join(parts, "")
	138	+	}
	139	+	// Generic conversion
	140	+	parts := strings.Split(cName, "_")
	141	+	for i, p := range parts {
	142	+	parts[i] = strings.Title(p)
	143	+	}
	144	+	return strings.Join(parts, "")
	145	+	}
	146	+
	147	+	// writeAll writes all generated files to disk.
	148	+	func writeAll(root string, files map[string][]byte) error {
	149	+	for path, content := range files {
	150	+	fullPath := filepath.Join(root, path)
	151	+	dir := filepath.Dir(fullPath)
	152	+	if err := os.MkdirAll(dir, 0755); err != nil {
	153	+	return fmt.Errorf("mkdir %s: %w", dir, err)
	154	+	}
	155	+	if err := os.WriteFile(fullPath, content, 0644); err != nil {
	156	+	return fmt.Errorf("write %s: %w", fullPath, err)
	157	+	}
	158	+	}
	159	+	return nil
	160	+	}
	161	+
	162	+	const capiTemplate = `// Code generated by pipewiregen. DO NOT EDIT.
	163	+
	164	+	package capi
	165	+
	166	+	import "github.com/ebitengine/purego"
	167	+
	168	+	{{range .Symbols}}
	169	+	// {{.Name}}Func is the function type for {{.Name}}.
	170	+	type {{.Name}}Func {{.Signature}}
	171	+	{{end}}
	172	+
	173	+	var (
	174	+	{{range .Symbols}}
	175	+	{{.Name}} {{.Name}}Func
	176	+	{{end}}
	177	+	)
	178	+
	179	+	func register{{.Group.Name \| title}}(handle uintptr) error {
	180	+	{{range .Symbols}}
	181	+	if err := purego.RegisterLibFunc(&{{.Name}}, handle, "{{.Name}}"); err != nil {
	182	+	return err
	183	+	}
	184	+	{{end}}
	185	+	return nil
	186	+	}
	187	+	`
	188	+
	189	+	const portTemplate = `// Code generated by pipewiregen. DO NOT EDIT.
	190	+
	191	+	package out
	192	+
	193	+	// {{.Group.Interface}} defines the outbound interface for {{.Group.Name}} operations.
	194	+	type {{.Group.Interface}} interface {
	195	+	{{range .Methods}}
	196	+	{{.GoName}} {{.Signature}}
	197	+	{{end}}
	198	+	}
	199	+	`

@@ -1,2 +1,199 @@
1	// Package emitter renders generated Go source files from the binding model.	1		// Package emitter renders generated Go source files from the binding model.
2	package emitter	2		package emitter
		3	+
		4	+	import (
		5	+	"bytes"
		6	+	"fmt"
		7	+	"os"
		8	+	"path/filepath"
		9	+	"strings"
		10	+	"text/template"
		11	+
		12	+	"github.com/bnema/purego-pipewire/cmd/pipewiregen/internal/model"
		13	+	)
		14	+
		15	+	// Emit generates Go source files from the model and writes them to the root directory.
		16	+	// It returns a map of generated file paths to their content.
		17	+	func Emit(m *model.Model, root string) (map[string][]byte, error) {
		18	+	out := make(map[string][]byte)
		19	+	for _, group := range m.Groups {
		20	+	capiPath := filepath.Join("internal", "capi", group.Name+"_gen.go")
		21	+	portPath := filepath.Join("internal", "ports", "out", group.Name+"_gen.go")
		22	+
		23	+	capiContent, err := renderCAPI(group, m.Symbols, m.Libraries)
		24	+	if err != nil {
		25	+	return nil, fmt.Errorf("render capi for group %q: %w", group.Name, err)
		26	+	}
		27	+	out[capiPath] = capiContent
		28	+
		29	+	portContent, err := renderPort(group, m.Symbols)
		30	+	if err != nil {
		31	+	return nil, fmt.Errorf("render port for group %q: %w", group.Name, err)
		32	+	}
		33	+	out[portPath] = portContent
		34	+	}
		35	+	return out, writeAll(root, out)
		36	+	}
		37	+
		38	+	// renderCAPI generates the raw C API function types and registration helpers.
		39	+	func renderCAPI(group model.Group, symbols []model.Symbol, libraries []model.Library) ([]byte, error) {
		40	+	// Find symbols belonging to this group
		41	+	groupSymbols := filterSymbolsByGroup(symbols, group.Name)
		42	+
		43	+	// Build library map for lookup
		44	+	libMap := make(map[string]string)
		45	+	for _, lib := range libraries {
		46	+	libMap[lib.Name] = lib.SOName
		47	+	}
		48	+
		49	+	data := struct {
		50	+	Group model.Group
		51	+	Symbols []model.Symbol
		52	+	LibraryMap map[string]string
		53	+	}{
		54	+	Group: group,
		55	+	Symbols: groupSymbols,
		56	+	LibraryMap: libMap,
		57	+	}
		58	+
		59	+	tmpl, err := template.New("capi").Funcs(template.FuncMap{
		60	+	"title": strings.Title,
		61	+	}).Parse(capiTemplate)
		62	+	if err != nil {
		63	+	return nil, err
		64	+	}
		65	+
		66	+	var buf bytes.Buffer
		67	+	if err := tmpl.Execute(&buf, data); err != nil {
		68	+	return nil, err
		69	+	}
		70	+	return buf.Bytes(), nil
		71	+	}
		72	+
		73	+	// renderPort generates the outbound interface definitions.
		74	+	func renderPort(group model.Group, symbols []model.Symbol) ([]byte, error) {
		75	+	groupSymbols := filterSymbolsByGroup(symbols, group.Name)
		76	+
		77	+	// Convert symbols to methods with proper Go names
		78	+	type Method struct {
		79	+	Name string
		80	+	GoName string
		81	+	Signature string
		82	+	CName string
		83	+	}
		84	+
		85	+	methods := make([]Method, 0, len(groupSymbols))
		86	+	for _, sym := range groupSymbols {
		87	+	methods = append(methods, Method{
		88	+	Name: sym.Name,
		89	+	GoName: toGoName(sym.Name),
		90	+	Signature: sym.Signature,
		91	+	CName: sym.Name,
		92	+	})
		93	+	}
		94	+
		95	+	data := struct {
		96	+	Group model.Group
		97	+	Methods []Method
		98	+	}{
		99	+	Group: group,
		100	+	Methods: methods,
		101	+	}
		102	+
		103	+	tmpl, err := template.New("port").Funcs(template.FuncMap{
		104	+	"title": strings.Title,
		105	+	}).Parse(portTemplate)
		106	+	if err != nil {
		107	+	return nil, err
		108	+	}
		109	+
		110	+	var buf bytes.Buffer
		111	+	if err := tmpl.Execute(&buf, data); err != nil {
		112	+	return nil, err
		113	+	}
		114	+	return buf.Bytes(), nil
		115	+	}
		116	+
		117	+	// filterSymbolsByGroup returns symbols that belong to the given group.
		118	+	func filterSymbolsByGroup(symbols []model.Symbol, groupName string) []model.Symbol {
		119	+	var result []model.Symbol
		120	+	for _, sym := range symbols {
		121	+	if sym.Group == groupName {
		122	+	result = append(result, sym)
		123	+	}
		124	+	}
		125	+	return result
		126	+	}
		127	+
		128	+	// toGoName converts a C function name like pw_init to a Go name like PWInit.
		129	+	func toGoName(cName string) string {
		130	+	// Handle pw_ prefix specially
		131	+	if strings.HasPrefix(cName, "pw_") {
		132	+	name := cName[3:]
		133	+	parts := strings.Split(name, "_")
		134	+	for i, p := range parts {
		135	+	parts[i] = strings.Title(p)
		136	+	}
		137	+	return "PW" + strings.Join(parts, "")
		138	+	}
		139	+	// Generic conversion
		140	+	parts := strings.Split(cName, "_")
		141	+	for i, p := range parts {
		142	+	parts[i] = strings.Title(p)
		143	+	}
		144	+	return strings.Join(parts, "")
		145	+	}
		146	+
		147	+	// writeAll writes all generated files to disk.
		148	+	func writeAll(root string, files map[string][]byte) error {
		149	+	for path, content := range files {
		150	+	fullPath := filepath.Join(root, path)
		151	+	dir := filepath.Dir(fullPath)
		152	+	if err := os.MkdirAll(dir, 0755); err != nil {
		153	+	return fmt.Errorf("mkdir %s: %w", dir, err)
		154	+	}
		155	+	if err := os.WriteFile(fullPath, content, 0644); err != nil {
		156	+	return fmt.Errorf("write %s: %w", fullPath, err)
		157	+	}
		158	+	}
		159	+	return nil
		160	+	}
		161	+
		162	+	const capiTemplate = `// Code generated by pipewiregen. DO NOT EDIT.
		163	+
		164	+	package capi
		165	+
		166	+	import "github.com/ebitengine/purego"
		167	+
		168	+	{{range .Symbols}}
		169	+	// {{.Name}}Func is the function type for {{.Name}}.
		170	+	type {{.Name}}Func {{.Signature}}
		171	+	{{end}}
		172	+
		173	+	var (
		174	+	{{range .Symbols}}
		175	+	{{.Name}} {{.Name}}Func
		176	+	{{end}}
		177	+	)
		178	+
		179	+	func register{{.Group.Name \| title}}(handle uintptr) error {
		180	+	{{range .Symbols}}
		181	+	if err := purego.RegisterLibFunc(&{{.Name}}, handle, "{{.Name}}"); err != nil {
		182	+	return err
		183	+	}
		184	+	{{end}}
		185	+	return nil
		186	+	}
		187	+	`
		188	+
		189	+	const portTemplate = `// Code generated by pipewiregen. DO NOT EDIT.
		190	+
		191	+	package out
		192	+
		193	+	// {{.Group.Interface}} defines the outbound interface for {{.Group.Name}} operations.
		194	+	type {{.Group.Interface}} interface {
		195	+	{{range .Methods}}
		196	+	{{.GoName}} {{.Signature}}
		197	+	{{end}}
		198	+	}
		199	+	`

M cmd/pipewiregen/internal/emitter/emitter_test.go +34 -0

@@ -1,1 +1,35 @@
1	1		package emitter
	2	+
	3	+	import (
	4	+	"testing"
	5	+
	6	+	"github.com/bnema/purego-pipewire/cmd/pipewiregen/internal/model"
	7	+	)
	8	+
	9	+	func testModel() *model.Model {
	10	+	return &model.Model{
	11	+	Libraries: []model.Library{
	12	+	{Name: "pipewire", SOName: "libpipewire-0.3.so.0"},
	13	+	},
	14	+	Groups: []model.Group{
	15	+	{Name: "init", Interface: "InitAPI", Package: "out", Symbols: []string{"pw_init", "pw_deinit"}},
	16	+	},
	17	+	Symbols: []model.Symbol{
	18	+	{Name: "pw_init", Library: "pipewire", Group: "init", Signature: "func(argc int32, argv **byte)"},
	19	+	{Name: "pw_deinit", Library: "pipewire", Group: "init", Signature: "func()"},
	20	+	},
	21	+	}
	22	+	}
	23	+
	24	+	func TestEmitWritesCAPIAndPortFiles(t *testing.T) {
	25	+	paths, err := Emit(testModel(), t.TempDir())
	26	+	if err != nil {
	27	+	t.Fatalf("Emit returned error: %v", err)
	28	+	}
	29	+	if _, ok := paths["internal/capi/init_gen.go"]; !ok {
	30	+	t.Fatalf("missing capi output")
	31	+	}
	32	+	if _, ok := paths["internal/ports/out/init_gen.go"]; !ok {
	33	+	t.Fatalf("missing port output")
	34	+	}
	35	+	}

@@ -1,1 +1,35 @@
1	package emitter	1		package emitter
		2	+
		3	+	import (
		4	+	"testing"
		5	+
		6	+	"github.com/bnema/purego-pipewire/cmd/pipewiregen/internal/model"
		7	+	)
		8	+
		9	+	func testModel() *model.Model {
		10	+	return &model.Model{
		11	+	Libraries: []model.Library{
		12	+	{Name: "pipewire", SOName: "libpipewire-0.3.so.0"},
		13	+	},
		14	+	Groups: []model.Group{
		15	+	{Name: "init", Interface: "InitAPI", Package: "out", Symbols: []string{"pw_init", "pw_deinit"}},
		16	+	},
		17	+	Symbols: []model.Symbol{
		18	+	{Name: "pw_init", Library: "pipewire", Group: "init", Signature: "func(argc int32, argv **byte)"},
		19	+	{Name: "pw_deinit", Library: "pipewire", Group: "init", Signature: "func()"},
		20	+	},
		21	+	}
		22	+	}
		23	+
		24	+	func TestEmitWritesCAPIAndPortFiles(t *testing.T) {
		25	+	paths, err := Emit(testModel(), t.TempDir())
		26	+	if err != nil {
		27	+	t.Fatalf("Emit returned error: %v", err)
		28	+	}
		29	+	if _, ok := paths["internal/capi/init_gen.go"]; !ok {
		30	+	t.Fatalf("missing capi output")
		31	+	}
		32	+	if _, ok := paths["internal/ports/out/init_gen.go"]; !ok {
		33	+	t.Fatalf("missing port output")
		34	+	}
		35	+	}

M cmd/pipewiregen/internal/model/model.go +6 -2


@@ -15,8 +15,10 @@ type Library struct {
15	15
16	16		// Group represents a logical grouping of symbols.
17	17		type Group struct {
18		-	Name string `json:"name"`
19		-	Symbols []string `json:"symbols"`
	18	+	Name string `json:"name"`
	19	+	Symbols []string `json:"symbols"`
	20	+	Interface string `json:"interface"`
	21	+	Package string `json:"package"`
20	22		}
21	23
22	24		// Symbol represents a single C function to bind.

@@ -24,4 +26,6 @@ type Symbol struct {
24	26		Name string `json:"name"`
25	27		Library string `json:"library"`
26	28		Signature string `json:"signature"`
	29	+	Optional bool `json:"optional,omitempty"`
	30	+	Group string `json:"group"`
27	31		}

 // Group represents a logical grouping of symbols.
 type Group struct {
-	Name    string   `json:"name"`
+	Name      string   `json:"name"`
-	Symbols []string `json:"symbols"`
+	Symbols   []string `json:"symbols"`
+	Interface string   `json:"interface"`
+	Package   string   `json:"package"`
 }
 // Symbol represents a single C function to bind.
 	Name      string `json:"name"`
 	Library   string `json:"library"`
 	Signature string `json:"signature"`
+	Optional  bool   `json:"optional,omitempty"`
+	Group     string `json:"group"`
 }

M cmd/pipewiregen/main.go +6 -2


@@ -5,6 +5,7 @@ import (
5	5		"os"
6	6		"path/filepath"
7	7
	8	+	"github.com/bnema/purego-pipewire/cmd/pipewiregen/internal/emitter"
8	9		"github.com/bnema/purego-pipewire/cmd/pipewiregen/internal/parser"
9	10		)
10	11

@@ -14,10 +15,13 @@ func main() {
14	15		fmt.Fprintf(os.Stderr, "pipewiregen: %v\n", err)
15	16		os.Exit(1)
16	17		}
17		-	_, err = parser.Load(filepath.Join(root, "gen", "pipewire.json"))
	18	+	pipewireModel, err := parser.Load(filepath.Join(root, "gen", "pipewire.json"))
18	19		if err != nil {
19	20		fmt.Fprintf(os.Stderr, "pipewiregen: %v\n", err)
20	21		os.Exit(1)
21	22		}
22		-	// Emit step will be added in Task 2.
	23	+	if _, err := emitter.Emit(pipewireModel, root); err != nil {
	24	+	fmt.Fprintf(os.Stderr, "pipewiregen: %v\n", err)
	25	+	os.Exit(1)
	26	+	}
23	27		}

 	"os"
 	"path/filepath"
+	"github.com/bnema/purego-pipewire/cmd/pipewiregen/internal/emitter"
 	"github.com/bnema/purego-pipewire/cmd/pipewiregen/internal/parser"
 )
 		fmt.Fprintf(os.Stderr, "pipewiregen: %v\n", err)
 		os.Exit(1)
 	}
-	_, err = parser.Load(filepath.Join(root, "gen", "pipewire.json"))
+	pipewireModel, err := parser.Load(filepath.Join(root, "gen", "pipewire.json"))
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "pipewiregen: %v\n", err)
 		os.Exit(1)
 	}
-	// Emit step will be added in Task 2.
+	if _, err := emitter.Emit(pipewireModel, root); err != nil {
+		fmt.Fprintf(os.Stderr, "pipewiregen: %v\n", err)
+		os.Exit(1)
+	}
 }

M gen/pipewire.json +3 -3


@@ -3,10 +3,10 @@
3	3		{"name": "pipewire", "soname": "libpipewire-0.3.so.0"}
4	4		],
5	5		"groups": [
6		-	{"name": "init", "symbols": ["pw_init", "pw_deinit"]}
	6	+	{"name": "init", "interface": "InitAPI", "package": "out", "symbols": ["pw_init", "pw_deinit"]}
7	7		],
8	8		"symbols": [
9		-	{"name": "pw_init", "library": "pipewire", "signature": "func(argc int32, argv **byte)"},
10		-	{"name": "pw_deinit", "library": "pipewire", "signature": "func()"}
	9	+	{"name": "pw_init", "library": "pipewire", "group": "init", "signature": "func(argc int32, argv **byte)"},
	10	+	{"name": "pw_deinit", "library": "pipewire", "group": "init", "signature": "func()"}
11	11		]
12	12		}


@@ -3,10 +3,10 @@
3		{"name": "pipewire", "soname": "libpipewire-0.3.so.0"}	3		{"name": "pipewire", "soname": "libpipewire-0.3.so.0"}
4		],	4		],
5		"groups": [	5		"groups": [
6	-	{"name": "init", "symbols": ["pw_init", "pw_deinit"]}	6	+	{"name": "init", "interface": "InitAPI", "package": "out", "symbols": ["pw_init", "pw_deinit"]}
7		],	7		],
8		"symbols": [	8		"symbols": [
9	-	{"name": "pw_init", "library": "pipewire", "signature": "func(argc int32, argv **byte)"},	9	+	{"name": "pw_init", "library": "pipewire", "group": "init", "signature": "func(argc int32, argv **byte)"},
10	-	{"name": "pw_deinit", "library": "pipewire", "signature": "func()"}	10	+	{"name": "pw_deinit", "library": "pipewire", "group": "init", "signature": "func()"}
11		]	11		]
12		}	12		}

A internal/capi/.gitkeep +0 -0

no textual change.

A internal/capi/init_gen.go +34 -0 generated file: collapsed

load diff

A internal/ports/out/.gitkeep +0 -0

no textual change.

A internal/ports/out/init_gen.go +12 -0 generated file: collapsed

load diff