libgo: Use waitpid on systems which do not have wait4.

From-SVN: r171758

libgo/Makefile.am

@@ -1246,13 +1246,20 @@ endif # !LIBGO_IS_SOLARIS
 endif # !LIBGO_IS_LINUX
 
 
-# Define ForkExec, PtraceForkExec, Exec, and Wait4.
+# Define ForkExec, PtraceForkExec, and Exec.
 if LIBGO_IS_RTEMS
 syscall_exec_os_file = syscalls/exec_stubs.go
 else
 syscall_exec_os_file = syscalls/exec.go
 endif
 
+# Define Wait4.
+if HAVE_WAIT4
+syscall_wait_file = syscalls/wait4.go
+else
+syscall_wait_file = syscalls/waitpid.go
+endif
+
 # Define Sleep.
 if LIBGO_IS_RTEMS
 syscall_sleep_file = syscalls/sleep_rtems.go
@@ -1329,6 +1336,7 @@ go_syscall_files = \
 	$(syscall_errstr_decl_file) \
 	syscalls/exec_helpers.go \
 	$(syscall_exec_os_file) \
+	$(syscall_wait_file) \
 	$(syscall_filesize_file) \
 	$(syscall_stat_file) \
 	$(syscall_sleep_file) \

libgo/Makefile.in

@@ -1632,8 +1632,12 @@ go_testing_script_files = \
 @LIBGO_IS_LINUX_TRUE@syscall_stat_file = syscalls/sysfile_stat_largefile.go
 @LIBGO_IS_RTEMS_FALSE@syscall_exec_os_file = syscalls/exec.go
 
-# Define ForkExec, PtraceForkExec, Exec, and Wait4.
+# Define ForkExec, PtraceForkExec, and Exec.
 @LIBGO_IS_RTEMS_TRUE@syscall_exec_os_file = syscalls/exec_stubs.go
+@HAVE_WAIT4_FALSE@syscall_wait_file = syscalls/waitpid.go
+
+# Define Wait4.
+@HAVE_WAIT4_TRUE@syscall_wait_file = syscalls/wait4.go
 @LIBGO_IS_RTEMS_FALSE@syscall_sleep_file = syscalls/sleep_select.go
 
 # Define Sleep.
@@ -1671,6 +1675,7 @@ go_syscall_files = \
 	$(syscall_errstr_decl_file) \
 	syscalls/exec_helpers.go \
 	$(syscall_exec_os_file) \
+	$(syscall_wait_file) \
 	$(syscall_filesize_file) \
 	$(syscall_stat_file) \
 	$(syscall_sleep_file) \

libgo/configure

@@ -603,6 +603,8 @@ am__EXEEXT_TRUE
 LTLIBOBJS
 LIBOBJS
 STRINGOPS_FLAG
+HAVE_WAIT4_FALSE
+HAVE_WAIT4_TRUE
 HAVE_STRERROR_R_FALSE
 HAVE_STRERROR_R_TRUE
 HAVE_SYS_MMAN_H_FALSE
@@ -10900,7 +10902,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 10903 "configure"
+#line 10905 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11006,7 +11008,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11009 "configure"
+#line 11011 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -14154,7 +14156,7 @@ else
 fi
 
 
-for ac_func in srandom random strerror_r strsignal
+for ac_func in srandom random strerror_r strsignal wait4
 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"
@@ -14175,6 +14177,14 @@ else
   HAVE_STRERROR_R_FALSE=
 fi
 
+ if test "$ac_cv_func_wait4" = yes; then
+  HAVE_WAIT4_TRUE=
+  HAVE_WAIT4_FALSE='#'
+else
+  HAVE_WAIT4_TRUE='#'
+  HAVE_WAIT4_FALSE=
+fi
+
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for __sync_bool_compare_and_swap_4" >&5
 $as_echo_n "checking for __sync_bool_compare_and_swap_4... " >&6; }
@@ -14552,6 +14562,10 @@ if test -z "${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
+if test -z "${HAVE_WAIT4_TRUE}" && test -z "${HAVE_WAIT4_FALSE}"; then
+  as_fn_error "conditional \"HAVE_WAIT4\" 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

@@ -381,8 +381,9 @@ 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 strerror_r strsignal)
+AC_CHECK_FUNCS(srandom random strerror_r strsignal wait4)
 AM_CONDITIONAL(HAVE_STRERROR_R, test "$ac_cv_func_strerror_r" = yes)
+AM_CONDITIONAL(HAVE_WAIT4, test "$ac_cv_func_wait4" = yes)
 
 AC_CACHE_CHECK([for __sync_bool_compare_and_swap_4],
 [libgo_cv_func___sync_bool_compare_and_swap_4],

libgo/mksysinfo.sh

@@ -377,6 +377,8 @@ if test "$rusage" != ""; then
     nrusage="$nrusage $field;"
   done
   echo "type Rusage struct {$nrusage }" >> ${OUT}
+else
+  echo "type Rusage struct {}" >> ${OUT}
 fi
 
 # The utsname struct.

libgo/syscalls/exec.go

@@ -17,7 +17,6 @@ func libc_chdir(name *byte) int __asm__ ("chdir")
 func libc_dup2(int, int) int __asm__ ("dup2")
 func libc_execve(*byte, **byte, **byte) int __asm__ ("execve")
 func libc_sysexit(int) __asm__ ("_exit")
-func libc_wait4(Pid_t, *int, int, *Rusage) Pid_t __asm__ ("wait4")
 
 // Fork, dup fd onto 0..len(fd), and exec(argv0, argvv, envv) in child.
 // If a dup or exec fails, write the errno int to pipe.
@@ -263,16 +262,3 @@ func Exec(argv0 string, argv []string, envv []string) (err int) {
 	libc_execve(StringBytePtr(argv0), &argv_arg[0], &envv_arg[0])
 	return GetErrno()
 }
-
-func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, errno int) {
-	var status int
-	r := libc_wait4(Pid_t(pid), &status, options, rusage)
-	wpid = int(r)
-	if r < 0 {
-		errno = GetErrno()
-	}
-	if wstatus != nil {
-		*wstatus = WaitStatus(status)
-	}
-	return
-}

libgo/syscalls/wait4.go

@@ -0,0 +1,22 @@
+// wait4.go -- Wait4 for systems with wait4.
+
+// 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
+
+func libc_wait4(Pid_t, *int, int, *Rusage) Pid_t __asm__ ("wait4")
+
+func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, errno int) {
+	var status int
+	r := libc_wait4(Pid_t(pid), &status, options, rusage)
+	wpid = int(r)
+	if r < 0 {
+		errno = GetErrno()
+	}
+	if wstatus != nil {
+		*wstatus = WaitStatus(status)
+	}
+	return
+}

libgo/syscalls/waitpid.go

@@ -0,0 +1,22 @@
+// waitpid.go -- Wait4 for systems without wait4, but with waitpid.
+
+// 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
+
+func libc_waitpid(Pid_t, *int, int) Pid_t __asm__ ("waitpid")
+
+func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, errno int) {
+	var status int
+	r := libc_waitpid(Pid_t(pid), &status, options)
+	wpid = int(r)
+	if r < 0 {
+		errno = GetErrno()
+	}
+	if wstatus != nil {
+		*wstatus = WaitStatus(status)
+	}
+	return
+}