cmd/dist, go/build: make cmd/dist generate cgoEnabled map for go/build

This reduces the amount of duplication. Now there is only one list
of platforms supporting cgo.

Update #12270.

Change-Id: I5dcd55cb6be7c5bb6ce560383c71d90ab1189dc9
Reviewed-on: https://go-review.googlesource.com/14278
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

diff --git a/src/cmd/dist/build.go b/src/cmd/dist/build.go
index 7f2f75341fabf7ca87bc7c7f0cfffdb6117f6a02..8ef73e7a89b361ff5b34ce405bb5326706b7984d 100644 (file)
--- a/src/cmd/dist/build.go
+++ b/src/cmd/dist/build.go
@@ -463,6 +463,9 @@ var deptab = []struct {
        {"runtime/internal/sys", []string{
                "zversion.go",
        }},
+       {"go/build", []string{
+               "zcgo.go",
+       }},
 }
 
 // depsuffix records the allowed suffixes for source files.
@@ -478,6 +481,7 @@ var gentab = []struct {
 }{
        {"zdefaultcc.go", mkzdefaultcc},
        {"zversion.go", mkzversion},
+       {"zcgo.go", mkzcgo},
 
        // not generated anymore, but delete the file if we see it
        {"enam.c", nil},
@@ -1061,9 +1065,9 @@ func cmdbootstrap() {
        }
 }
 
-// Copied from go/build/build.go.
 // Cannot use go/build directly because cmd/dist for a new release
 // builds against an old release's go/build, which may be out of sync.
+// To reduce duplication, we generate the list for go/build from this.
 var cgoEnabled = map[string]bool{
        "darwin/386":      true,
        "darwin/amd64":    true,

diff --git a/src/cmd/dist/buildgo.go b/src/cmd/dist/buildgo.go
index 437e9dd9a0f7b24ef5508adfe08854862a100cc4..3dc9ff0dde30fd9eb0e077f951bf4df995e1acbf 100644 (file)
--- a/src/cmd/dist/buildgo.go
+++ b/src/cmd/dist/buildgo.go
@@ -4,7 +4,10 @@
 
 package main
 
-import "fmt"
+import (
+       "bytes"
+       "fmt"
+)
 
 /*
  * Helpers for building cmd/go and cmd/cgo.
@@ -37,3 +40,26 @@ func mkzdefaultcc(dir, file string) {
        file = file[:i] + "c" + file[i:]
        writefile(out, file, writeSkipSame)
 }
+
+// mkzcgo writes zcgo.go for go/build package:
+//
+//     package build
+//  var cgoEnabled = map[string]bool{}
+//
+// It is invoked to write go/build/zcgo.go.
+func mkzcgo(dir, file string) {
+       var buf bytes.Buffer
+
+       fmt.Fprintf(&buf,
+               "// auto generated by go tool dist\n"+
+                       "\n"+
+                       "package build\n"+
+                       "\n"+
+                       "var cgoEnabled = map[string]bool{\n")
+       for plat := range cgoEnabled {
+               fmt.Fprintf(&buf, "\t%q: true,\n", plat)
+       }
+       fmt.Fprintf(&buf, "}")
+
+       writefile(buf.String(), file, writeSkipSame)
+}

diff --git a/src/go/build/build.go b/src/go/build/build.go
index c1b70bcdd75133f35d74eed2ca251e718f52c8f5..e524925d0dccd361d28a5df5d651037aa94b052a 100644 (file)
--- a/src/go/build/build.go
+++ b/src/go/build/build.go
@@ -256,34 +256,6 @@ func (ctxt *Context) SrcDirs() []string {
 // if set, or else the compiled code's GOARCH, GOOS, and GOROOT.
 var Default Context = defaultContext()
 
-// Also known to cmd/dist/build.go.
-var cgoEnabled = map[string]bool{
-       "darwin/386":      true,
-       "darwin/amd64":    true,
-       "darwin/arm":      true,
-       "darwin/arm64":    true,
-       "dragonfly/amd64": true,
-       "freebsd/386":     true,
-       "freebsd/amd64":   true,
-       "freebsd/arm":     true,
-       "linux/386":       true,
-       "linux/amd64":     true,
-       "linux/arm":       true,
-       "linux/arm64":     true,
-       "linux/ppc64le":   true,
-       "android/386":     true,
-       "android/amd64":   true,
-       "android/arm":     true,
-       "netbsd/386":      true,
-       "netbsd/amd64":    true,
-       "netbsd/arm":      true,
-       "openbsd/386":     true,
-       "openbsd/amd64":   true,
-       "solaris/amd64":   true,
-       "windows/386":     true,
-       "windows/amd64":   true,
-}
-
 func defaultContext() Context {
        var c Context