main.go

Documentation: go.uber.org/atomic/internal/gen-atomicint

     1  // Copyright (c) 2020-2022 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  // gen-atomicint generates an atomic wrapper around an integer type.
    22  //
    23  //	gen-atomicint -name Int32 -wrapped int32 -file out.go
    24  //
    25  // The generated wrapper will use the functions in the sync/atomic package
    26  // named after the generated type.
    27  package main
    28  
    29  import (
    30  	"bytes"
    31  	"embed"
    32  	"errors"
    33  	"flag"
    34  	"fmt"
    35  	"go/format"
    36  	"io"
    37  	"log"
    38  	"os"
    39  	"text/template"
    40  	"time"
    41  )
    42  
    43  func main() {
    44  	log.SetFlags(0)
    45  	if err := run(os.Args[1:]); err != nil {
    46  		log.Fatalf("%+v", err)
    47  	}
    48  }
    49  
    50  func run(args []string) error {
    51  	var opts struct {
    52  		Name     string
    53  		Wrapped  string
    54  		File     string
    55  		Unsigned bool
    56  	}
    57  
    58  	flag := flag.NewFlagSet("gen-atomicint", flag.ContinueOnError)
    59  
    60  	flag.StringVar(&opts.Name, "name", "", "name of the generated type (e.g. Int32)")
    61  	flag.StringVar(&opts.Wrapped, "wrapped", "", "name of the wrapped type (e.g. int32)")
    62  	flag.StringVar(&opts.File, "file", "", "output file path (default: stdout)")
    63  	flag.BoolVar(&opts.Unsigned, "unsigned", false, "whether the type is unsigned")
    64  
    65  	if err := flag.Parse(args); err != nil {
    66  		return err
    67  	}
    68  
    69  	if len(opts.Name) == 0 || len(opts.Wrapped) == 0 {
    70  		return errors.New("flags -name and -wrapped are required")
    71  	}
    72  
    73  	var w io.Writer = os.Stdout
    74  	if file := opts.File; len(file) > 0 {
    75  		f, err := os.Create(file)
    76  		if err != nil {
    77  			return fmt.Errorf("create %q: %v", file, err)
    78  		}
    79  		defer f.Close()
    80  
    81  		w = f
    82  	}
    83  
    84  	data := struct {
    85  		Name     string
    86  		Wrapped  string
    87  		Unsigned bool
    88  		ToYear   int
    89  	}{
    90  		Name:     opts.Name,
    91  		Wrapped:  opts.Wrapped,
    92  		Unsigned: opts.Unsigned,
    93  		ToYear:   time.Now().Year(),
    94  	}
    95  
    96  	var buff bytes.Buffer
    97  	if err := _tmpl.ExecuteTemplate(&buff, "wrapper.tmpl", data); err != nil {
    98  		return fmt.Errorf("render template: %v", err)
    99  	}
   100  
   101  	bs, err := format.Source(buff.Bytes())
   102  	if err != nil {
   103  		return fmt.Errorf("reformat source: %v", err)
   104  	}
   105  
   106  	io.WriteString(w, "// @generated Code generated by gen-atomicint.\n\n")
   107  	_, err = w.Write(bs)
   108  	return err
   109  }
   110  
   111  var (
   112  	//go:embed *.tmpl
   113  	_tmplFS embed.FS
   114  
   115  	_tmpl = template.Must(template.New("atomicint").ParseFS(_tmplFS, "*.tmpl"))
   116  )
   117
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