buildgo.go

Documentation: cmd/dist

     1  // Copyright 2012 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  package main
     6  
     7  import (
     8  	"bytes"
     9  	"fmt"
    10  	"os"
    11  	"path/filepath"
    12  	"sort"
    13  	"strings"
    14  )
    15  
    16  /*
    17   * Helpers for building cmd/go and cmd/cgo.
    18   */
    19  
    20  // mkzdefaultcc writes zdefaultcc.go:
    21  //
    22  //	package main
    23  //	const defaultCC = <defaultcc>
    24  //	const defaultCXX = <defaultcxx>
    25  //	const defaultPkgConfig = <defaultpkgconfig>
    26  //
    27  // It is invoked to write cmd/go/internal/cfg/zdefaultcc.go
    28  // but we also write cmd/cgo/zdefaultcc.go
    29  func mkzdefaultcc(dir, file string) {
    30  	if strings.Contains(file, filepath.FromSlash("go/internal/cfg")) {
    31  		var buf bytes.Buffer
    32  		fmt.Fprintf(&buf, "// Code generated by go tool dist; DO NOT EDIT.\n")
    33  		fmt.Fprintln(&buf)
    34  		fmt.Fprintf(&buf, "package cfg\n")
    35  		fmt.Fprintln(&buf)
    36  		fmt.Fprintf(&buf, "const DefaultPkgConfig = `%s`\n", defaultpkgconfig)
    37  		buf.WriteString(defaultCCFunc("DefaultCC", defaultcc))
    38  		buf.WriteString(defaultCCFunc("DefaultCXX", defaultcxx))
    39  		writefile(buf.String(), file, writeSkipSame)
    40  		return
    41  	}
    42  
    43  	var buf bytes.Buffer
    44  	fmt.Fprintf(&buf, "// Code generated by go tool dist; DO NOT EDIT.\n")
    45  	fmt.Fprintln(&buf)
    46  	fmt.Fprintf(&buf, "package main\n")
    47  	fmt.Fprintln(&buf)
    48  	fmt.Fprintf(&buf, "const defaultPkgConfig = `%s`\n", defaultpkgconfig)
    49  	buf.WriteString(defaultCCFunc("defaultCC", defaultcc))
    50  	buf.WriteString(defaultCCFunc("defaultCXX", defaultcxx))
    51  	writefile(buf.String(), file, writeSkipSame)
    52  }
    53  
    54  func defaultCCFunc(name string, defaultcc map[string]string) string {
    55  	var buf bytes.Buffer
    56  
    57  	fmt.Fprintf(&buf, "func %s(goos, goarch string) string {\n", name)
    58  	fmt.Fprintf(&buf, "\tswitch goos+`/`+goarch {\n")
    59  	var keys []string
    60  	for k := range defaultcc {
    61  		if k != "" {
    62  			keys = append(keys, k)
    63  		}
    64  	}
    65  	sort.Strings(keys)
    66  	for _, k := range keys {
    67  		fmt.Fprintf(&buf, "\tcase %q:\n\t\treturn %q\n", k, defaultcc[k])
    68  	}
    69  	fmt.Fprintf(&buf, "\t}\n")
    70  	fmt.Fprintf(&buf, "\treturn %q\n", defaultcc[""])
    71  	fmt.Fprintf(&buf, "}\n")
    72  
    73  	return buf.String()
    74  }
    75  
    76  // mkzcgo writes zosarch.go for cmd/go.
    77  func mkzosarch(dir, file string) {
    78  	// sort for deterministic zosarch.go file
    79  	var list []string
    80  	for plat := range cgoEnabled {
    81  		list = append(list, plat)
    82  	}
    83  	sort.Strings(list)
    84  
    85  	var buf bytes.Buffer
    86  	fmt.Fprintf(&buf, "// Code generated by go tool dist; DO NOT EDIT.\n\n")
    87  	fmt.Fprintf(&buf, "package cfg\n\n")
    88  	fmt.Fprintf(&buf, "var OSArchSupportsCgo = map[string]bool{\n")
    89  	for _, plat := range list {
    90  		fmt.Fprintf(&buf, "\t%q: %v,\n", plat, cgoEnabled[plat])
    91  	}
    92  	fmt.Fprintf(&buf, "}\n")
    93  
    94  	writefile(buf.String(), file, writeSkipSame)
    95  }
    96  
    97  // mkzcgo writes zcgo.go for the go/build package:
    98  //
    99  //	package build
   100  //  var cgoEnabled = map[string]bool{}
   101  //
   102  // It is invoked to write go/build/zcgo.go.
   103  func mkzcgo(dir, file string) {
   104  	// sort for deterministic zcgo.go file
   105  	var list []string
   106  	for plat, hasCgo := range cgoEnabled {
   107  		if hasCgo {
   108  			list = append(list, plat)
   109  		}
   110  	}
   111  	sort.Strings(list)
   112  
   113  	var buf bytes.Buffer
   114  	fmt.Fprintf(&buf, "// Code generated by go tool dist; DO NOT EDIT.\n")
   115  	fmt.Fprintln(&buf)
   116  	fmt.Fprintf(&buf, "package build\n")
   117  	fmt.Fprintln(&buf)
   118  	fmt.Fprintf(&buf, "const defaultCGO_ENABLED = %q\n", os.Getenv("CGO_ENABLED"))
   119  	fmt.Fprintln(&buf)
   120  	fmt.Fprintf(&buf, "var cgoEnabled = map[string]bool{\n")
   121  	for _, plat := range list {
   122  		fmt.Fprintf(&buf, "\t%q: true,\n", plat)
   123  	}
   124  	fmt.Fprintf(&buf, "}\n")
   125  
   126  	writefile(buf.String(), file, writeSkipSame)
   127  }
   128
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