stringer.go

Documentation: cmd/internal/obj

     1  // Copyright 2015 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build ignore
     6  
     7  // This is a mini version of the stringer tool customized for the Anames table
     8  // in the architecture support for obj.
     9  // This version just generates the slice of strings, not the String method.
    10  
    11  package main
    12  
    13  import (
    14  	"bufio"
    15  	"flag"
    16  	"fmt"
    17  	"log"
    18  	"os"
    19  	"regexp"
    20  	"strings"
    21  )
    22  
    23  var (
    24  	input  = flag.String("i", "", "input file name")
    25  	output = flag.String("o", "", "output file name")
    26  	pkg    = flag.String("p", "", "package name")
    27  )
    28  
    29  var Are = regexp.MustCompile(`^\tA([A-Za-z0-9]+)`)
    30  
    31  func main() {
    32  	flag.Parse()
    33  	if *input == "" || *output == "" || *pkg == "" {
    34  		flag.Usage()
    35  		os.Exit(2)
    36  	}
    37  	in, err := os.Open(*input)
    38  	if err != nil {
    39  		log.Fatal(err)
    40  	}
    41  	fd, err := os.Create(*output)
    42  	if err != nil {
    43  		log.Fatal(err)
    44  	}
    45  	out := bufio.NewWriter(fd)
    46  	defer out.Flush()
    47  	var on = false
    48  	s := bufio.NewScanner(in)
    49  	first := true
    50  	for s.Scan() {
    51  		line := s.Text()
    52  		if !on {
    53  			// First relevant line contains "= obj.ABase".
    54  			// If we find it, delete the = so we don't stop immediately.
    55  			const prefix = "= obj.ABase"
    56  			index := strings.Index(line, prefix)
    57  			if index < 0 {
    58  				continue
    59  			}
    60  			// It's on. Start with the header.
    61  			fmt.Fprintf(out, header, *input, *output, *pkg, *pkg)
    62  			on = true
    63  			line = line[:index]
    64  		}
    65  		// Strip comments so their text won't defeat our heuristic.
    66  		index := strings.Index(line, "//")
    67  		if index > 0 {
    68  			line = line[:index]
    69  		}
    70  		index = strings.Index(line, "/*")
    71  		if index > 0 {
    72  			line = line[:index]
    73  		}
    74  		// Termination condition: Any line with an = changes the sequence,
    75  		// so stop there, and stop at a closing brace.
    76  		if strings.HasPrefix(line, "}") || strings.ContainsRune(line, '=') {
    77  			break
    78  		}
    79  		sub := Are.FindStringSubmatch(line)
    80  		if len(sub) < 2 {
    81  			continue
    82  		}
    83  		if first {
    84  			fmt.Fprintf(out, "\tobj.A_ARCHSPECIFIC: %q,\n", sub[1])
    85  			first = false
    86  		} else {
    87  			fmt.Fprintf(out, "\t%q,\n", sub[1])
    88  		}
    89  	}
    90  	fmt.Fprintln(out, "}")
    91  	if s.Err() != nil {
    92  		log.Fatal(err)
    93  	}
    94  }
    95  
    96  const header = `// Code generated by stringer -i %s -o %s -p %s; DO NOT EDIT.
    97  
    98  package %s
    99  
   100  import "cmd/internal/obj"
   101  
   102  var Anames = []string{
   103  `
   104
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