ebiten/internal/shaderlister/main.go
2024-11-17 15:44:51 +09:00

401 lines
9.4 KiB
Go

// Copyright 2024 The Ebitengine Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package main
import (
"bufio"
"encoding/json"
"flag"
"fmt"
"go/ast"
"go/constant"
"go/token"
"go/types"
"log/slog"
"os"
"regexp"
"strings"
"golang.org/x/tools/go/ast/inspector"
"golang.org/x/tools/go/packages"
"github.com/hajimehoshi/ebiten/v2/internal/graphics"
"github.com/hajimehoshi/ebiten/v2/internal/shaderir/glsl"
"github.com/hajimehoshi/ebiten/v2/internal/shaderir/hlsl"
"github.com/hajimehoshi/ebiten/v2/internal/shaderir/msl"
"github.com/hajimehoshi/ebiten/v2/internal/shaderir/pssl"
)
var flagTarget = flag.String("target", "", "shader compilation targets separated by comma (e.g. 'glsl,glsles,hlsl,msl')")
func main() {
if err := xmain(); err != nil {
fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
}
type Shader struct {
Package string
File string
Source string
SourceHash string
GLSL *GLSL `json:",omitempty"`
GLSLES *GLSLES `json:",omitempty"`
HLSL *HLSL `json:",omitempty"`
MSL *MSL `json:",omitempty"`
PSSL *PSSL `json:",omitempty"`
}
type GLSL struct {
Vertex string
Fragment string
}
type GLSLES struct {
Vertex string
Fragment string
}
type HLSL struct {
Vertex string
Pixel string
}
type MSL struct {
Shader string
}
type PSSL struct {
Vertex string
Pixel string
}
func xmain() error {
flag.Usage = func() {
fmt.Fprintln(os.Stderr, "shaderlister [-target=TARGET] [package]")
os.Exit(2)
}
flag.Parse()
if len(flag.Args()) < 1 {
flag.Usage()
}
pkgs, err := packages.Load(&packages.Config{
Mode: packages.NeedName | packages.NeedImports | packages.NeedDeps | packages.NeedTypes | packages.NeedSyntax | packages.NeedTypesInfo,
}, flag.Args()...)
if err != nil {
return err
}
var targets []string
if ft := strings.TrimSpace(*flagTarget); ft != "" {
for _, t := range strings.Split(ft, ",") {
targets = append(targets, strings.TrimSpace(t))
}
}
// Collect shader information.
// Even if no shader is found, the output should be a JSON array. Start with an empty slice, not nil.
shaders := []Shader{}
var visitErr error
packages.Visit(pkgs, func(pkg *packages.Package) bool {
path := pkg.PkgPath
// A standard library should not have a directive for shaders. Skip them.
if isStandardImportPath(path) {
return true
}
// A semi-standard library should not have a directive for shaders. Skip them.
if strings.HasPrefix(path, "golang.org/x/") {
return true
}
origN := len(shaders)
shaders = appendShaderSources(shaders, pkg)
// Add source hashes.
for i := range shaders[origN:] {
shader := &shaders[i]
hash, err := graphics.CalcSourceHash([]byte(shader.Source))
if err != nil {
visitErr = err
return false
}
shader.SourceHash = hash.String()
}
// Compile shaders.
if len(targets) == 0 {
return true
}
for i := range shaders[origN:] {
if err := compile(&shaders[i], targets); err != nil {
visitErr = err
return false
}
}
return true
}, nil)
if visitErr != nil {
return visitErr
}
w := bufio.NewWriter(os.Stdout)
enc := json.NewEncoder(w)
enc.SetIndent("", "\t")
if err := enc.Encode(shaders); err != nil {
return err
}
if err := w.Flush(); err != nil {
return err
}
return nil
}
// isStandardImportPath reports whether $GOROOT/src/path should be considered part of the standard distribution.
//
// This is based on the implementation in the standard library (cmd/go/internal/search/search.go).
func isStandardImportPath(path string) bool {
head, _, _ := strings.Cut(path, "/")
return !strings.Contains(head, ".")
}
const directive = "ebitengine:shader"
var reDirective = regexp.MustCompile(`(?m)^\s*//` + regexp.QuoteMeta(directive))
func hasShaderDirectiveInComment(commentGroup *ast.CommentGroup) bool {
for _, line := range commentGroup.List {
if reDirective.MatchString(line.Text) {
return true
}
}
return false
}
func appendShaderSources(shaders []Shader, pkg *packages.Package) []Shader {
topLevelDecls := map[ast.Decl]struct{}{}
for _, file := range pkg.Syntax {
for _, decl := range file.Decls {
topLevelDecls[decl] = struct{}{}
}
}
isTopLevelDecl := func(decl ast.Decl) bool {
_, ok := topLevelDecls[decl]
return ok
}
var genDeclStack []*ast.GenDecl
in := inspector.New(pkg.Syntax)
in.Nodes([]ast.Node{
(*ast.GenDecl)(nil),
(*ast.ValueSpec)(nil),
}, func(n ast.Node, push bool) bool {
switch n := n.(type) {
case *ast.GenDecl:
genDecl := n
// It is possible to check whether decl.Tok is token.CONST or not,
// but move on without checking it for better warning messages.
if push {
// If the GenDecl is with parentheses (e.g. `const ( ... )`), check the GenDecl's comment.
// The directive doesn't work, so if the directive is found, warn it.
if genDecl.Lparen != token.NoPos {
if genDecl.Doc != nil && hasShaderDirectiveInComment(genDecl.Doc) {
pos := pkg.Fset.Position(genDecl.Doc.Pos())
slog.Warn(fmt.Sprintf("misplaced %s directive", directive),
"package", pkg.PkgPath,
"file", pos.Filename,
"line", pos.Line,
"column", pos.Column)
}
} else {
if genDecl.Doc == nil {
return false
}
if !hasShaderDirectiveInComment(genDecl.Doc) {
return false
}
}
// It is possible to check whether genCecl is top-level or not,
// but move on without checking it for better warning messages.
genDeclStack = append(genDeclStack, genDecl)
} else {
genDeclStack = genDeclStack[:len(genDeclStack)-1]
}
return true
case *ast.ValueSpec:
spec := n
genDecl := genDeclStack[len(genDeclStack)-1]
// If the ValueSpec is in parentheses (e.g. `const ( ... )`), check the ValueSpec's comment.
if genDecl.Lparen != token.NoPos {
if spec.Doc == nil {
return false
}
if !hasShaderDirectiveInComment(spec.Doc) {
return false
}
}
var docPos token.Pos
if spec.Doc != nil {
docPos = spec.Doc.Pos()
} else {
docPos = genDecl.Doc.Pos()
}
if !isTopLevelDecl(genDecl) {
pos := pkg.Fset.Position(docPos)
slog.Warn(fmt.Sprintf("misplaced %s directive", directive),
"package", pkg.PkgPath,
"file", pos.Filename,
"line", pos.Line,
"column", pos.Column)
return false
}
// Avoid multiple names like `const a, b = "foo", "bar"` to avoid confusions.
if len(spec.Names) != 1 {
pos := pkg.Fset.Position(docPos)
slog.Warn(fmt.Sprintf("%s cannot apply to multiple declarations", directive),
"package", pkg.PkgPath,
"file", pos.Filename,
"line", pos.Line,
"column", pos.Column)
return false
}
// Check if the ValueSpec is a const declaration.
name := spec.Names[0]
def := pkg.TypesInfo.Defs[name]
c, ok := def.(*types.Const)
if !ok {
pos := pkg.Fset.Position(docPos)
slog.Warn(fmt.Sprintf("%s cannot apply to %s", directive, objectTypeString(def)),
"package", pkg.PkgPath,
"file", pos.Filename,
"line", pos.Line,
"column", pos.Column)
return false
}
// Check the constant type.
val := c.Val()
if val.Kind() != constant.String {
pos := pkg.Fset.Position(docPos)
slog.Warn(fmt.Sprintf("%s cannot apply to const type of %s", directive, val.Kind()),
"package", pkg.PkgPath,
"file", pos.Filename,
"line", pos.Line,
"column", pos.Column)
return false
}
shaders = append(shaders, Shader{
Package: pkg.PkgPath,
File: pkg.Fset.Position(spec.Pos()).Filename,
Source: constant.StringVal(val),
})
return false
default:
return false
}
})
return shaders
}
func objectTypeString(obj types.Object) string {
switch obj := obj.(type) {
case *types.PkgName:
return "package"
case *types.Const:
return "const"
case *types.TypeName:
return "type"
case *types.Var:
if obj.IsField() {
return "field"
}
return "var"
case *types.Func:
return "func"
case *types.Label:
return "label"
case *types.Builtin:
return "builtin"
case *types.Nil:
return "nil"
default:
return fmt.Sprintf("objectTypeString(%T)", obj)
}
}
func compile(shader *Shader, targets []string) error {
ir, err := graphics.CompileShader([]byte(shader.Source))
if err != nil {
return fmt.Errorf("compiling shader failed: %w", err)
}
for _, target := range targets {
switch target {
case "glsl":
vs, fs := glsl.Compile(ir, glsl.GLSLVersionDefault)
shader.GLSL = &GLSL{
Vertex: vs,
Fragment: fs,
}
case "glsles":
vs, fs := glsl.Compile(ir, glsl.GLSLVersionES300)
shader.GLSLES = &GLSLES{
Vertex: vs,
Fragment: fs,
}
case "hlsl":
vs, ps, _ := hlsl.Compile(ir)
shader.HLSL = &HLSL{
Vertex: vs,
Pixel: ps,
}
case "msl":
s := msl.Compile(ir)
shader.MSL = &MSL{
Shader: s,
}
case "pssl":
vs, ps := pssl.Compile(ir)
shader.PSSL = &PSSL{
Vertex: vs,
Pixel: ps,
}
default:
return fmt.Errorf("unsupported target: %s", target)
}
}
return nil
}