1 // Copyright 2016 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.
7 // mkpost processes the output of cgo -godefs to
8 // modify the generated types. It is used to clean up
9 // the sys API in an architecture specific manner.
11 // mkpost is run after cgo -godefs; see README.md.
25 // Get the OS and architecture (using GOARCH_TARGET if it exists)
26 goos := os.Getenv("GOOS")
27 goarch := os.Getenv("GOARCH_TARGET")
29 goarch = os.Getenv("GOARCH")
31 // Check that we are using the Docker-based build system if we should be.
33 if os.Getenv("GOLANG_SYS_BUILD") != "docker" {
34 os.Stderr.WriteString("In the Docker-based build system, mkpost should not be called directly.\n")
35 os.Stderr.WriteString("See README.md\n")
40 b, err := ioutil.ReadAll(os.Stdin)
46 // Replace type of Atim, Mtim and Ctim by Timespec in Stat_t
47 // to avoid having both StTimespec and Timespec.
48 sttimespec := regexp.MustCompile(`_Ctype_struct_st_timespec`)
49 b = sttimespec.ReplaceAll(b, []byte("Timespec"))
52 // Intentionally export __val fields in Fsid and Sigset_t
53 valRegex := regexp.MustCompile(`type (Fsid|Sigset_t) struct {(\s+)X__(bits|val)(\s+\S+\s+)}`)
54 b = valRegex.ReplaceAll(b, []byte("type $1 struct {${2}Val$4}"))
56 // Intentionally export __fds_bits field in FdSet
57 fdSetRegex := regexp.MustCompile(`type (FdSet) struct {(\s+)X__fds_bits(\s+\S+\s+)}`)
58 b = fdSetRegex.ReplaceAll(b, []byte("type $1 struct {${2}Bits$3}"))
60 // Intentionally export __icmp6_filt field in icmpv6_filter
61 icmpV6Regex := regexp.MustCompile(`type (ICMPv6Filter) struct {(\s+)X__icmp6_filt(\s+\S+\s+)}`)
62 b = icmpV6Regex.ReplaceAll(b, []byte("type $1 struct {${2}Filt$3}"))
64 // If we have empty Ptrace structs, we should delete them. Only s390x emits
65 // nonempty Ptrace structs.
66 ptraceRexexp := regexp.MustCompile(`type Ptrace((Psw|Fpregs|Per) struct {\s*})`)
67 b = ptraceRexexp.ReplaceAll(b, nil)
69 // Replace the control_regs union with a blank identifier for now.
70 controlRegsRegex := regexp.MustCompile(`(Control_regs)\s+\[0\]uint64`)
71 b = controlRegsRegex.ReplaceAll(b, []byte("_ [0]uint64"))
73 // Remove fields that are added by glibc
74 // Note that this is unstable as the identifers are private.
75 removeFieldsRegex := regexp.MustCompile(`X__glibc\S*`)
76 b = removeFieldsRegex.ReplaceAll(b, []byte("_"))
78 // Convert [65]int8 to [65]byte in Utsname members to simplify
79 // conversion to string; see golang.org/issue/20753
80 convertUtsnameRegex := regexp.MustCompile(`((Sys|Node|Domain)name|Release|Version|Machine)(\s+)\[(\d+)\]u?int8`)
81 b = convertUtsnameRegex.ReplaceAll(b, []byte("$1$3[$4]byte"))
83 // Convert [n]int8 to [n]byte in Statvfs_t members to simplify
84 // conversion to string.
85 convertStatvfsRegex := regexp.MustCompile(`((Fstype|Mnton|Mntfrom)name)(\s+)\[(\d+)\]int8`)
86 b = convertStatvfsRegex.ReplaceAll(b, []byte("$1$3[$4]byte"))
88 // Convert []int8 to []byte in device mapper ioctl interface
89 convertDmIoctlNames := regexp.MustCompile(`(Name|Uuid|Target_type|Data)(\s+)\[(\d+)\]u?int8`)
90 dmIoctlTypes := regexp.MustCompile(`type Dm(\S+) struct {[^}]*}`)
91 dmStructs := dmIoctlTypes.FindAll(b, -1)
92 for _, s := range dmStructs {
93 newNames := convertDmIoctlNames.ReplaceAll(s, []byte("$1$2[$3]byte"))
94 b = bytes.Replace(b, s, newNames, 1)
97 // Convert []int8 to []byte in ctl_info ioctl interface
98 convertCtlInfoName := regexp.MustCompile(`(Name)(\s+)\[(\d+)\]int8`)
99 ctlInfoType := regexp.MustCompile(`type CtlInfo struct {[^}]*}`)
100 ctlInfoStructs := ctlInfoType.FindAll(b, -1)
101 for _, s := range ctlInfoStructs {
102 newNames := convertCtlInfoName.ReplaceAll(s, []byte("$1$2[$3]byte"))
103 b = bytes.Replace(b, s, newNames, 1)
106 // Convert [1024]int8 to [1024]byte in Ptmget members
107 convertPtmget := regexp.MustCompile(`([SC]n)(\s+)\[(\d+)\]u?int8`)
108 b = convertPtmget.ReplaceAll(b, []byte("$1[$3]byte"))
110 // Remove spare fields (e.g. in Statx_t)
111 spareFieldsRegex := regexp.MustCompile(`X__spare\S*`)
112 b = spareFieldsRegex.ReplaceAll(b, []byte("_"))
114 // Remove cgo padding fields
115 removePaddingFieldsRegex := regexp.MustCompile(`Pad_cgo_\d+`)
116 b = removePaddingFieldsRegex.ReplaceAll(b, []byte("_"))
118 // Remove padding, hidden, or unused fields
119 removeFieldsRegex = regexp.MustCompile(`\b(X_\S+|Padding)`)
120 b = removeFieldsRegex.ReplaceAll(b, []byte("_"))
122 // Remove the first line of warning from cgo
123 b = b[bytes.IndexByte(b, '\n')+1:]
124 // Modify the command in the header to include:
125 // mkpost, our own warning, and a build tag.
126 replacement := fmt.Sprintf(`$1 | go run mkpost.go
127 // Code generated by the command above; see README.md. DO NOT EDIT.
129 // +build %s,%s`, goarch, goos)
130 cgoCommandRegex := regexp.MustCompile(`(cgo -godefs .*)`)
131 b = cgoCommandRegex.ReplaceAll(b, []byte(replacement))
133 // Rename Stat_t time fields
134 if goos == "freebsd" && goarch == "386" {
135 // Hide Stat_t.[AMCB]tim_ext fields
136 renameStatTimeExtFieldsRegex := regexp.MustCompile(`[AMCB]tim_ext`)
137 b = renameStatTimeExtFieldsRegex.ReplaceAll(b, []byte("_"))
139 renameStatTimeFieldsRegex := regexp.MustCompile(`([AMCB])(?:irth)?time?(?:spec)?\s+(Timespec|StTimespec)`)
140 b = renameStatTimeFieldsRegex.ReplaceAll(b, []byte("${1}tim ${2}"))
143 b, err = format.Source(b)