runtime, os: fix the build on Solaris

Reviewed-on: https://go-review.googlesource.com/137535

From-SVN: r264593

gcc/go/gofrontend/MERGE

@@ -1,4 +1,4 @@
-652fbfb7acfd81ceffe28e20984464aa7bb6024d
+e7b98cf0a380eb45791cd5c52897224a686dcdec
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/go/os/executable_solaris.go

@@ -4,14 +4,18 @@
 
 package os
 
-import "syscall"
+import (
+	"syscall"
+	_ "unsafe" // for go:linkname
+)
 
-var executablePath string // set by sysauxv in ../runtime/os3_solaris.go
+// solarisExecutablePath is defined in the runtime package.
+func solarisExecutablePath() string
 
 var initCwd, initCwdErr = Getwd()
 
 func executable() (string, error) {
-	path := executablePath
+	path := solarisExecutablePath()
 	if len(path) == 0 {
 		path, err := syscall.Getexecname()
 		if err != nil {

libgo/go/runtime/os3_solaris.go

@@ -0,0 +1,54 @@
+// 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 runtime
+
+import (
+	"runtime/internal/sys"
+	"unsafe"
+)
+
+var executablePath string
+
+func sysargs(argc int32, argv **byte) {
+	n := argc + 1
+
+	// skip over argv, envp to get to auxv
+	for argv_index(argv, n) != nil {
+		n++
+	}
+
+	// skip NULL separator
+	n++
+
+	// now argv+n is auxv
+	auxv := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*sys.PtrSize))
+	sysauxv(auxv[:])
+}
+
+const (
+	_AT_NULL         = 0    // Terminates the vector
+	_AT_PAGESZ       = 6    // Page size in bytes
+	_AT_SUN_EXECNAME = 2014 // exec() path name
+)
+
+func sysauxv(auxv []uintptr) {
+	for i := 0; auxv[i] != _AT_NULL; i += 2 {
+		tag, val := auxv[i], auxv[i+1]
+		switch tag {
+		case _AT_PAGESZ:
+			physPageSize = val
+		case _AT_SUN_EXECNAME:
+			executablePath = gostringnocopy((*byte)(unsafe.Pointer(val)))
+		}
+	}
+}
+
+//go:linkname solarisExecutablePath os.solarisExecutablePath
+
+// solarisExecutablePath is called from the os package to fetch the
+// saved executable path.
+func solarisExecutablePath() string {
+	return executablePath
+}

libgo/go/runtime/stubs3.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 // +build !plan9
-// +build !solaris
 // +build !windows
 // +build !nacl
 // +build !freebsd