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// Copyright 2021 The Tint 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.
// builtin-gen parses the <tint>/src/tint/builtins.def file, then scans the
// project directory for '<file>.tmpl' files, to produce '<file>' source code
// files.
package main
import (
"flag"
"fmt"
"io/ioutil"
"os"
"path/filepath"
"strings"
"dawn.googlesource.com/tint/tools/src/cmd/builtin-gen/gen"
"dawn.googlesource.com/tint/tools/src/cmd/builtin-gen/parser"
"dawn.googlesource.com/tint/tools/src/cmd/builtin-gen/resolver"
"dawn.googlesource.com/tint/tools/src/fileutils"
"dawn.googlesource.com/tint/tools/src/glob"
)
const defProjectRelPath = "src/tint/builtins.def"
func main() {
if err := run(); err != nil {
fmt.Println(err)
os.Exit(1)
}
}
func showUsage() {
fmt.Println(`
builtin-gen generates the builtin table for the Tint compiler
builtin-gen parses the <tint>/src/tint/builtins.def file, then scans the project
directory for '<file>.tmpl' files, to produce '<file>' source code files.
usage:
builtin-gen
optional flags:`)
flag.PrintDefaults()
fmt.Println(``)
os.Exit(1)
}
func run() error {
// Load the builtins definition file
projectRoot := fileutils.ProjectRoot()
defPath := filepath.Join(projectRoot, defProjectRelPath)
defSource, err := ioutil.ReadFile(defPath)
if err != nil {
return err
}
// Parse the definition file to produce an AST
ast, err := parser.Parse(string(defSource), defProjectRelPath)
if err != nil {
return err
}
// Resolve the AST to produce the semantic info
sem, err := resolver.Resolve(ast)
if err != nil {
return err
}
// Recursively find all the template files in the <tint>/src directory
files, err := glob.Scan(projectRoot, glob.MustParseConfig(`{
"paths": [{"include": [
"src/**.tmpl",
"test/**.tmpl"
]}]
}`))
if err != nil {
return err
}
// For each template file...
for _, relTmplPath := range files {
// Make tmplPath absolute
tmplPath := filepath.Join(projectRoot, relTmplPath)
// Read the template file
tmpl, err := ioutil.ReadFile(tmplPath)
if err != nil {
return fmt.Errorf("failed to open '%v': %w", tmplPath, err)
}
// Create or update the file at relpath if the file content has changed
// relpath is a path relative to the template
writeFile := func(relpath, body string) error {
// Write the common file header
sb := strings.Builder{}
sb.WriteString(fmt.Sprintf(header, filepath.ToSlash(relTmplPath), filepath.ToSlash(defProjectRelPath)))
sb.WriteString(body)
content := sb.String()
abspath := filepath.Join(filepath.Dir(tmplPath), relpath)
return writeFileIfChanged(abspath, content)
}
// Write the content generated using the template and semantic info
sb := strings.Builder{}
if err := gen.Generate(sem, string(tmpl), &sb, writeFile); err != nil {
return fmt.Errorf("while processing '%v': %w", tmplPath, err)
}
if body := sb.String(); body != "" {
_, tmplFileName := filepath.Split(tmplPath)
outFileName := strings.TrimSuffix(tmplFileName, ".tmpl")
if err := writeFile(outFileName, body); err != nil {
return err
}
}
}
return nil
}
// writes content to path if the file has changed
func writeFileIfChanged(path, content string) error {
existing, err := ioutil.ReadFile(path)
if err == nil && string(existing) == content {
return nil // Not changed
}
if err := os.MkdirAll(filepath.Dir(path), 0777); err != nil {
return fmt.Errorf("failed to create directory for '%v': %w", path, err)
}
if err := ioutil.WriteFile(path, []byte(content), 0666); err != nil {
return fmt.Errorf("failed to write file '%v': %w", path, err)
}
return nil
}
const header = `// Copyright 2021 The Tint 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.
////////////////////////////////////////////////////////////////////////////////
// File generated by tools/builtin-gen
// using the template:
// %v
// and the builtin defintion file:
// %v
//
// Do not modify this file directly
////////////////////////////////////////////////////////////////////////////////
`