unix: add various missing syscalls available on Linux

Various syscalls offered by x/sys/unix on Linux are not available on
Solaris and should be, such as Mkfifo, Getwd(), Futimes() and others.
In particular, all of the *at() variants of existing functions were
added where appropriate.

Getgroups() was fixed to use the correct value for its sanity check on
the maximum number of groups.

Utimesnano() was updated to use the native Solaris utimensat function
for setting nanosecond-precision time.

Utimes() was updated to have the same error semantics and checking as
other platforms.

Getgroups(), anysocktoaddr(), and Recvmsg() were fixed to check the
return value before assuming syscall failure instead of relying solely
on errno being set.

mksyscall_solaris.pl needed some updates to better match the output of
the one found in syscall.

mkerrors.sh needed some updates to work out of the box on Solaris,
matching those recently done to the one in syscall.

The signatures (names) of some function parameters were changed to be
consistent with other platforms for the sake of documentation.

Fixes #8609

Change-Id: I9e4e2fee6d3ecfad9f4d845a5702ffde5166e804
Reviewed-on: https://go-review.googlesource.com/14643Reviewed-by: Aram Hăvărneanu <aram@mgk.ro>

unix/mkerrors.sh

@@ -12,12 +12,17 @@ export LC_ALL=C
 export LC_CTYPE=C
 
 if test -z "$GOARCH" -o -z "$GOOS"; then
-  echo 1>&2 "GOARCH or GOOS not defined in environment"
-  exit 1
+	echo 1>&2 "GOARCH or GOOS not defined in environment"
+	exit 1
 fi
 
 CC=${CC:-gcc}
 
+if [[ "$GOOS" -eq "solaris" ]]; then
+	# Assumes GNU versions of utilities in PATH.
+	export PATH=/usr/gnu/bin:$PATH
+fi
+
 uname=$(uname)
 
 includes_Darwin='
@@ -200,6 +205,7 @@ includes_OpenBSD='
 '
 
 includes_SunOS='
+#include <limits.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/sockio.h>

unix/mksyscall_solaris.pl

@@ -110,9 +110,9 @@ while(<>) {
 	$sysname =~ y/A-Z/a-z/; # All libc functions are lowercase.
 
 	# Runtime import of function to allow cross-platform builds.
-	$dynimports .= "//go:cgo_import_dynamic ${modname}_${sysname} ${sysname} \"$modname.so\"\n";
+	$dynimports .= "//go:cgo_import_dynamic libc_${sysname} ${sysname} \"$modname.so\"\n";
 	# Link symbol to proc address variable.
-	$linknames .= "//go:linkname ${sysvarname} ${modname}_${sysname}\n";
+	$linknames .= "//go:linkname ${sysvarname} libc_${sysname}\n";
 	# Library proc address variable.
 	push @vars, $sysvarname;
 

unix/types_solaris.go

@@ -15,8 +15,14 @@ package unix
 
 /*
 #define KERNEL
+// These defines ensure that builds done on newer versions of Solaris are
+// backwards-compatible with older versions of Solaris and
+// OpenSolaris-based derivatives.
+#define __USE_SUNOS_SOCKETS__          // msghdr
+#define __USE_LEGACY_PROTOTYPES__      // iovec
 #include <dirent.h>
 #include <fcntl.h>
+#include <limits.h>
 #include <signal.h>
 #include <termios.h>
 #include <stdio.h>
@@ -30,7 +36,9 @@ package unix
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/time.h>
+#include <sys/times.h>
 #include <sys/types.h>
+#include <sys/utsname.h>
 #include <sys/un.h>
 #include <sys/wait.h>
 #include <net/bpf.h>
@@ -40,6 +48,8 @@ package unix
 #include <netinet/in.h>
 #include <netinet/icmp6.h>
 #include <netinet/tcp.h>
+#include <ustat.h>
+#include <utime.h>
 
 enum {
 	sizeofPtr = sizeof(void*),
@@ -69,6 +79,7 @@ const (
 	sizeofInt      = C.sizeof_int
 	sizeofLong     = C.sizeof_long
 	sizeofLongLong = C.sizeof_longlong
+	PathMax        = C.PATH_MAX
 )
 
 // Basic types
@@ -88,6 +99,10 @@ type Timeval C.struct_timeval
 
 type Timeval32 C.struct_timeval32
 
+type Tms C.struct_tms
+
+type Utimbuf C.struct_utimbuf
+
 // Processes
 
 type Rusage C.struct_rusage
@@ -175,6 +190,20 @@ const (
 
 type FdSet C.fd_set
 
+// Misc
+
+type Utsname C.struct_utsname
+
+type Ustat_t C.struct_ustat
+
+const (
+	AT_FDCWD            = C.AT_FDCWD
+	AT_SYMLINK_NOFOLLOW = C.AT_SYMLINK_NOFOLLOW
+	AT_SYMLINK_FOLLOW   = C.AT_SYMLINK_FOLLOW
+	AT_REMOVEDIR        = C.AT_REMOVEDIR
+	AT_EACCESS          = C.AT_EACCESS
+)
+
 // Routing and interface messages
 
 const (

unix/ztypes_solaris_amd64.go

+// +build amd64,solaris
 // Created by cgo -godefs - DO NOT EDIT
 // cgo -godefs types_solaris.go
 
-// +build amd64,solaris
-
 package unix
 
 const (
@@ -11,6 +10,7 @@ const (
 	sizeofInt      = 0x4
 	sizeofLong     = 0x8
 	sizeofLongLong = 0x8
+	PathMax        = 0x400
 )
 
 type (
@@ -35,6 +35,18 @@ type Timeval32 struct {
 	Usec int32
 }
 
+type Tms struct {
+	Utime  int64
+	Stime  int64
+	Cutime int64
+	Cstime int64
+}
+
+type Utimbuf struct {
+	Actime  int64
+	Modtime int64
+}
+
 type Rusage struct {
 	Utime    Timeval
 	Stime    Timeval
@@ -230,6 +242,30 @@ type FdSet struct {
 	Bits [1024]int64
 }
 
+type Utsname struct {
+	Sysname  [257]int8
+	Nodename [257]int8
+	Release  [257]int8
+	Version  [257]int8
+	Machine  [257]int8
+}
+
+type Ustat_t struct {
+	Tfree     int64
+	Tinode    uint64
+	Fname     [6]int8
+	Fpack     [6]int8
+	Pad_cgo_0 [4]byte
+}
+
+const (
+	AT_FDCWD            = -0x2e6aad
+	AT_SYMLINK_NOFOLLOW = 0x1000
+	AT_SYMLINK_FOLLOW   = 0x2000
+	AT_REMOVEDIR        = 0x1
+	AT_EACCESS          = 0x4
+)
+
 const (
 	SizeofIfMsghdr  = 0x54
 	SizeofIfData    = 0x44