libgo: Support systems which do not have strerror_r.

From-SVN: r171757

libgo/Makefile.am

@@ -1264,7 +1264,11 @@ endif
 if LIBGO_IS_RTEMS
 syscall_errstr_file = syscalls/errstr_rtems.go
 else
+if HAVE_STRERROR_R
 syscall_errstr_file = syscalls/errstr.go
+else
+syscall_errstr_file = syscalls/errstr_nor.go
+endif
 endif
 
 # Declare libc_strerror_r which is the Go name for strerror_r.
@@ -1273,7 +1277,7 @@ if LIBGO_IS_RTEMS
 syscall_errstr_decl_file = syscalls/errstr_decl_rtems.go
 else
 if LIBGO_IS_LINUX
-# In Linux the POSIX strerror_r is called __xpg_strerror_r.
+# On GNU/Linux the POSIX strerror_r is called __xpg_strerror_r.
 syscall_errstr_decl_file = syscalls/errstr_decl_linux.go
 else
 # On other systems we hope strerror_r is just strerror_r.

libgo/Makefile.in

@@ -1638,13 +1638,14 @@ go_testing_script_files = \
 
 # Define Sleep.
 @LIBGO_IS_RTEMS_TRUE@syscall_sleep_file = syscalls/sleep_rtems.go
-@LIBGO_IS_RTEMS_FALSE@syscall_errstr_file = syscalls/errstr.go
+@HAVE_STRERROR_R_FALSE@@LIBGO_IS_RTEMS_FALSE@syscall_errstr_file = syscalls/errstr_nor.go
+@HAVE_STRERROR_R_TRUE@@LIBGO_IS_RTEMS_FALSE@syscall_errstr_file = syscalls/errstr.go
 
 # Define Errstr.
 @LIBGO_IS_RTEMS_TRUE@syscall_errstr_file = syscalls/errstr_rtems.go
 # On other systems we hope strerror_r is just strerror_r.
 @LIBGO_IS_LINUX_FALSE@@LIBGO_IS_RTEMS_FALSE@syscall_errstr_decl_file = syscalls/errstr_decl.go
-# In Linux the POSIX strerror_r is called __xpg_strerror_r.
+# On GNU/Linux the POSIX strerror_r is called __xpg_strerror_r.
 @LIBGO_IS_LINUX_TRUE@@LIBGO_IS_RTEMS_FALSE@syscall_errstr_decl_file = syscalls/errstr_decl_linux.go
 
 # Declare libc_strerror_r which is the Go name for strerror_r.

libgo/configure

@@ -603,6 +603,8 @@ am__EXEEXT_TRUE
 LTLIBOBJS
 LIBOBJS
 STRINGOPS_FLAG
+HAVE_STRERROR_R_FALSE
+HAVE_STRERROR_R_TRUE
 HAVE_SYS_MMAN_H_FALSE
 HAVE_SYS_MMAN_H_TRUE
 PTHREAD_LIBS
@@ -10898,7 +10900,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 10901 "configure"
+#line 10903 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11004,7 +11006,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11007 "configure"
+#line 11009 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -14151,7 +14153,8 @@ else
   HAVE_SYS_MMAN_H_FALSE=
 fi
 
-for ac_func in srandom random strsignal
+
+for ac_func in srandom random strerror_r strsignal
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
@@ -14164,6 +14167,14 @@ _ACEOF
 fi
 done
 
+ if test "$ac_cv_func_strerror_r" = yes; then
+  HAVE_STRERROR_R_TRUE=
+  HAVE_STRERROR_R_FALSE='#'
+else
+  HAVE_STRERROR_R_TRUE='#'
+  HAVE_STRERROR_R_FALSE=
+fi
+
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for __sync_bool_compare_and_swap_4" >&5
 $as_echo_n "checking for __sync_bool_compare_and_swap_4... " >&6; }
@@ -14537,6 +14548,10 @@ if test -z "${HAVE_SYS_MMAN_H_TRUE}" && test -z "${HAVE_SYS_MMAN_H_FALSE}"; then
   as_fn_error "conditional \"HAVE_SYS_MMAN_H\" was never defined.
 Usually this means the macro was only invoked conditionally." "$LINENO" 5
 fi
+if test -z "${HAVE_STRERROR_R_TRUE}" && test -z "${HAVE_STRERROR_R_FALSE}"; then
+  as_fn_error "conditional \"HAVE_STRERROR_R\" was never defined.
+Usually this means the macro was only invoked conditionally." "$LINENO" 5
+fi
 
 : ${CONFIG_STATUS=./config.status}
 ac_write_fail=0

libgo/configure.ac

@@ -380,7 +380,9 @@ esac
 
 AC_CHECK_HEADERS(sys/mman.h syscall.h sys/epoll.h sys/ptrace.h sys/syscall.h sys/user.h sys/utsname.h)
 AM_CONDITIONAL(HAVE_SYS_MMAN_H, test "$ac_cv_header_sys_mman_h" = yes)
-AC_CHECK_FUNCS(srandom random strsignal)
+
+AC_CHECK_FUNCS(srandom random strerror_r strsignal)
+AM_CONDITIONAL(HAVE_STRERROR_R, test "$ac_cv_func_strerror_r" = yes)
 
 AC_CACHE_CHECK([for __sync_bool_compare_and_swap_4],
 [libgo_cv_func___sync_bool_compare_and_swap_4],

libgo/syscalls/errstr_nor.go

+// errstr.go -- Error strings when there is no strerror_r.
+
+// 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 syscall
+
+import (
+	"sync"
+	"unsafe"
+)
+
+func libc_strerror(int) *byte __asm__ ("strerror")
+
+var errstr_lock sync.Mutex
+
+func Errstr(errno int) string {
+	errstr_lock.Lock()
+
+	bp := libc_strerror(errno)
+	b := (*[1000]byte)(unsafe.Pointer(bp))
+	i := 0
+	for b[i] != 0 {
+		i++
+	}
+	s := string(b[:i])
+
+	errstr_lock.Unlock()
+
+	return s
+}