goinstall: handle $(GOOS) and $(GOARCH) in filenames

This enables goinstall to handle .go and .c files (for cgo)
which are named after the following patterns:

    name_$(GOOS).*
    name_$(GOARCH).*
    name_$(GOOS)_$(GOARCH).*

Files with those names are only included if the $(GOOS) and
$(GOARCH) match the current system.

R=rsc
CC=golang-dev
https://golang.org/cl/4172055

.hgignore

@@ -37,6 +37,7 @@ src/cmd/gc/opnames.h
 src/cmd/gc/y.output
 src/cmd/gc/y1.tab.c
 src/cmd/gc/yerr.h
+src/cmd/goinstall/syslist.go
 src/pkg/Make.deps
 src/pkg/exp/ogle/ogle
 src/pkg/os/signal/unix.go

src/Make.inc

@@ -29,14 +29,20 @@ ifeq ($(GOOS),)
 GOOS:=$(GOHOSTOS)
 endif
 
-ifeq ($(GOOS),darwin)
-else ifeq ($(GOOS),freebsd)
-else ifeq ($(GOOS),linux)
-else ifeq ($(GOOS),tiny)
-else ifeq ($(GOOS),plan9)
-else ifeq ($(GOOS),windows)
-else
-$(error Invalid $$GOOS '$(GOOS)'; must be darwin, freebsd, linux, plan9, tiny, or windows)
+GOOS_LIST=\
+	darwin\
+	freebsd\
+	linux\
+	plan9\
+	windows\
+
+GOARCH_LIST=\
+	386\
+	amd64\
+	arm\
+
+ifeq ($(filter $(GOOS),$(GOOS_LIST)),)
+$(error Invalid $$GOOS '$(GOOS)'; must be one of: $(GOOS_LIST))
 endif
 
 ifeq ($(GOHOSTARCH),)
@@ -59,24 +65,25 @@ ifeq ($(GOOS),darwin)
 GOHOSTARCH:=$(GOARCH)
 endif
 
+ifeq ($(filter $(GOARCH),$(GOARCH_LIST)),)
+$(error Invalid $$GOARCH '$(GOARCH)'; must be one of: $(GOARCH_LIST))
+endif
+
 ifeq ($(GOARCH),386)
 O:=8
 else ifeq ($(GOARCH),amd64)
 O:=6
 else ifeq ($(GOARCH),arm)
-
 O:=5
-ifeq ($(GOOS),linux)
-else
+ifneq ($(GOOS),linux)
 $(error Invalid $$GOOS '$(GOOS)' for GOARCH=arm; must be linux)
 endif
-
 else
-$(error Invalid $$GOARCH '$(GOARCH)'; must be 386, amd64, or arm)
+$(error Missing $$O for '$(GOARCH)')
 endif
 
 # Save for recursive make to avoid recomputing.
-export GOARCH GOOS GOHOSTARCH GOHOSTOS
+export GOARCH GOOS GOHOSTARCH GOHOSTOS GOARCH_LIST GOOS_LIST
 
 # ugly hack to deal with whitespaces in $GOROOT
 nullstring :=

src/cmd/goinstall/Makefile

@@ -10,5 +10,17 @@ GOFILES=\
 	main.go\
 	make.go\
 	parse.go\
+	syslist.go\
+
+CLEANFILES+=syslist.go
 
 include ../../Make.cmd
+
+syslist.go:
+	echo '// Generated automatically by make.' >$@
+	echo 'package main' >>$@
+	echo 'const goosList = "$(GOOS_LIST)"' >>$@
+	echo 'const goarchList = "$(GOARCH_LIST)"' >>$@
+
+test:
+	gotest

src/cmd/goinstall/parse.go

@@ -14,6 +14,7 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"runtime"
 )
 
 
@@ -57,6 +58,9 @@ func scanDir(dir string, allowMain bool) (info *dirInfo, err os.Error) {
 		if strings.HasPrefix(d.Name, "_") || strings.Index(d.Name, ".cgo") != -1 {
 			continue
 		}
+		if !goodOSArch(d.Name) {
+			continue
+		}
 		if strings.HasSuffix(d.Name, ".c") {
 			cFiles = append(cFiles, d.Name)
 			continue
@@ -108,3 +112,47 @@ func scanDir(dir string, allowMain bool) (info *dirInfo, err os.Error) {
 	}
 	return &dirInfo{goFiles, cgoFiles, cFiles, imports, pkgName}, nil
 }
+
+// goodOSArch returns false if the filename contains a $GOOS or $GOARCH
+// suffix which does not match the current system.
+// The recognized filename formats are:
+//
+//     name_$(GOOS).*
+//     name_$(GOARCH).*
+//     name_$(GOOS)_$(GOARCH).*
+//
+func goodOSArch(filename string) bool {
+	if dot := strings.Index(filename, "."); dot != -1 {
+		filename = filename[:dot]
+	}
+	l := strings.Split(filename, "_", -1)
+	n := len(l)
+	if n == 0 {
+		return true
+	}
+	if good, known := goodOS[l[n-1]]; known {
+		return good
+	}
+	if good, known := goodArch[l[n-1]]; known {
+		if !good || n < 2 {
+			return false
+		}
+		good, known = goodOS[l[n-2]]
+		return good || !known
+	}
+	return true
+}
+
+var goodOS = make(map[string]bool)
+var goodArch = make(map[string]bool)
+
+func init() {
+	goodOS = make(map[string]bool)
+	goodArch = make(map[string]bool)
+	for _, v := range strings.Fields(goosList) {
+		goodOS[v] = v == runtime.GOOS
+	}
+	for _, v := range strings.Fields(goarchList) {
+		goodArch[v] = v == runtime.GOARCH
+	}
+}

src/cmd/goinstall/syslist_test.go

+// Copyright 2011 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+package main
+
+import (
+	"runtime"
+	"testing"
+)
+
+var (
+	thisOS    = runtime.GOOS
+	thisArch  = runtime.GOARCH
+	otherOS   = "freebsd"
+	otherArch = "arm"
+)
+
+func init() {
+	if thisOS == otherOS {
+		otherOS = "linux"
+	}
+	if thisArch == otherArch {
+		otherArch = "amd64"
+	}
+}
+
+type GoodFileTest struct {
+	name   string
+	result bool
+}
+
+var tests = []GoodFileTest{
+	{"file.go", true},
+	{"file.c", true},
+	{"file_foo.go", true},
+	{"file_" + thisArch + ".go", true},
+	{"file_" + otherArch + ".go", false},
+	{"file_" + thisOS + ".go", true},
+	{"file_" + otherOS + ".go", false},
+	{"file_" + thisOS + "_" + thisArch + ".go", true},
+	{"file_" + otherOS + "_" + thisArch + ".go", false},
+	{"file_" + thisOS + "_" + otherArch + ".go", false},
+	{"file_" + otherOS + "_" + otherArch + ".go", false},
+	{"file_foo_" + thisArch + ".go", true},
+	{"file_foo_" + otherArch + ".go", false},
+	{"file_" + thisOS + ".c", true},
+	{"file_" + otherOS + ".c", false},
+}
+
+func TestGoodOSArch(t *testing.T) {
+	for _, test := range tests {
+		if goodOSArch(test.name) != test.result {
+			t.Fatalf("goodOSArch(%q) != %v", test.name, test.result)
+		}
+	}
+}

src/pkg/Makefile

@@ -189,7 +189,6 @@ NOTEST=\
 	../cmd/ebnflint\
 	../cmd/godoc\
 	../cmd/gofmt\
-	../cmd/goinstall\
 	../cmd/govet\
 	../cmd/goyacc\
 	../cmd/hgpatch\