syscall: support Getwd on all BSDs

All supported BSDs provide the SYS___GETCWD syscall which can be used to
implement syscall.Getwd. With this change os.Getwd can use a single
syscall instead of falling back to the current kludge solution on the
BSDs.

This doesn't add any new exported functions to the frozen syscall
package, only ImplementsGetwd changes to true for dragonfly, freebsd,
netbsd and openbsd.

As suggested by Ian, this follows CL 83755 which did the same for
golang.org/x/sys/unix.

Also, an entry for netbsd/arm is added to mkall.sh which was used to
generate the syscall wrappers there.

Change-Id: I84da1ec61a6b8625443699a63cde556b6442ad41
Reviewed-on: https://go-review.googlesource.com/84484
Reviewed-by: Ian Lance Taylor <iant@golang.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/api/except.txt b/api/except.txt
index f8cd0faf646..ea4fa0eb9db 100644
--- a/api/except.txt
+++ b/api/except.txt
@@ -15,25 +15,30 @@ pkg syscall (darwin-amd64-cgo), func Fchflags(string, int) error
 pkg syscall (freebsd-386), const AF_MAX = 38
 pkg syscall (freebsd-386), const DLT_MATCHING_MAX = 242
 pkg syscall (freebsd-386), const ELAST = 94
+pkg syscall (freebsd-386), const ImplementsGetwd = false
 pkg syscall (freebsd-386), const O_CLOEXEC = 0
 pkg syscall (freebsd-386), func Fchflags(string, int) error
 pkg syscall (freebsd-386-cgo), const AF_MAX = 38
 pkg syscall (freebsd-386-cgo), const DLT_MATCHING_MAX = 242
 pkg syscall (freebsd-386-cgo), const ELAST = 94
+pkg syscall (freebsd-386-cgo), const ImplementsGetwd = false
 pkg syscall (freebsd-386-cgo), const O_CLOEXEC = 0
 pkg syscall (freebsd-amd64), const AF_MAX = 38
 pkg syscall (freebsd-amd64), const DLT_MATCHING_MAX = 242
 pkg syscall (freebsd-amd64), const ELAST = 94
+pkg syscall (freebsd-amd64), const ImplementsGetwd = false
 pkg syscall (freebsd-amd64), const O_CLOEXEC = 0
 pkg syscall (freebsd-amd64), func Fchflags(string, int) error
 pkg syscall (freebsd-amd64-cgo), const AF_MAX = 38
 pkg syscall (freebsd-amd64-cgo), const DLT_MATCHING_MAX = 242
 pkg syscall (freebsd-amd64-cgo), const ELAST = 94
+pkg syscall (freebsd-amd64-cgo), const ImplementsGetwd = false
 pkg syscall (freebsd-amd64-cgo), const O_CLOEXEC = 0
 pkg syscall (freebsd-arm), const AF_MAX = 38
 pkg syscall (freebsd-arm), const BIOCGRTIMEOUT = 1074545262
 pkg syscall (freebsd-arm), const BIOCSRTIMEOUT = 2148287085
 pkg syscall (freebsd-arm), const ELAST = 94
+pkg syscall (freebsd-arm), const ImplementsGetwd = false
 pkg syscall (freebsd-arm), const O_CLOEXEC = 0
 pkg syscall (freebsd-arm), const SIOCAIFADDR = 2151967019
 pkg syscall (freebsd-arm), const SIOCGIFSTATUS = 3274991931
@@ -65,6 +70,7 @@ pkg syscall (freebsd-arm-cgo), const AF_MAX = 38
 pkg syscall (freebsd-arm-cgo), const BIOCGRTIMEOUT = 1074545262
 pkg syscall (freebsd-arm-cgo), const BIOCSRTIMEOUT = 2148287085
 pkg syscall (freebsd-arm-cgo), const ELAST = 94
+pkg syscall (freebsd-arm-cgo), const ImplementsGetwd = false
 pkg syscall (freebsd-arm-cgo), const O_CLOEXEC = 0
 pkg syscall (freebsd-arm-cgo), const SIOCAIFADDR = 2151967019
 pkg syscall (freebsd-arm-cgo), const SIOCGIFSTATUS = 3274991931
@@ -98,6 +104,12 @@ pkg syscall (linux-amd64), type Cmsghdr struct, X__cmsg_data [0]uint8
 pkg syscall (linux-amd64-cgo), type Cmsghdr struct, X__cmsg_data [0]uint8
 pkg syscall (linux-arm), type Cmsghdr struct, X__cmsg_data [0]uint8
 pkg syscall (linux-arm-cgo), type Cmsghdr struct, X__cmsg_data [0]uint8
+pkg syscall (netbsd-386), const ImplementsGetwd = false
+pkg syscall (netbsd-386-cgo), const ImplementsGetwd = false
+pkg syscall (netbsd-amd64), const ImplementsGetwd = false
+pkg syscall (netbsd-amd64-cgo), const ImplementsGetwd = false
+pkg syscall (netbsd-arm), const ImplementsGetwd = false
+pkg syscall (netbsd-arm-cgo), const ImplementsGetwd = false
 pkg syscall (netbsd-arm), const SizeofIfData = 132
 pkg syscall (netbsd-arm), func Fchflags(string, int) error
 pkg syscall (netbsd-arm), type IfMsghdr struct, Pad_cgo_1 [4]uint8
@@ -106,6 +118,7 @@ pkg syscall (netbsd-arm-cgo), func Fchflags(string, int) error
 pkg syscall (netbsd-arm-cgo), type IfMsghdr struct, Pad_cgo_1 [4]uint8
 pkg syscall (openbsd-386), const BIOCGRTIMEOUT = 1074283118
 pkg syscall (openbsd-386), const BIOCSRTIMEOUT = 2148024941
+pkg syscall (openbsd-386), const ImplementsGetwd = false
 pkg syscall (openbsd-386), const RTF_FMASK = 63496
 pkg syscall (openbsd-386), const RTM_VERSION = 4
 pkg syscall (openbsd-386), const SIOCBRDGDADDR = 2150132039
@@ -158,6 +171,7 @@ pkg syscall (openbsd-386), type Timespec struct, Sec int32
 pkg syscall (openbsd-386), type Timeval struct, Sec int32
 pkg syscall (openbsd-386-cgo), const BIOCGRTIMEOUT = 1074283118
 pkg syscall (openbsd-386-cgo), const BIOCSRTIMEOUT = 2148024941
+pkg syscall (openbsd-386-cgo), const ImplementsGetwd = false
 pkg syscall (openbsd-386-cgo), const RTF_FMASK = 63496
 pkg syscall (openbsd-386-cgo), const RTM_VERSION = 4
 pkg syscall (openbsd-386-cgo), const SIOCBRDGDADDR = 2150132039
@@ -220,6 +234,7 @@ pkg syscall (openbsd-amd64), const EFER_NXE = 2048
 pkg syscall (openbsd-amd64), const EFER_NXE ideal-int
 pkg syscall (openbsd-amd64), const EFER_SCE = 1
 pkg syscall (openbsd-amd64), const EFER_SCE ideal-int
+pkg syscall (openbsd-amd64), const ImplementsGetwd = false
 pkg syscall (openbsd-amd64), const PMC5_PIPELINE_FLUSH = 21
 pkg syscall (openbsd-amd64), const PMC5_PIPELINE_FLUSH ideal-int
 pkg syscall (openbsd-amd64), const RTF_FMASK = 63496
@@ -282,6 +297,7 @@ pkg syscall (openbsd-amd64-cgo), const EFER_NXE = 2048
 pkg syscall (openbsd-amd64-cgo), const EFER_NXE ideal-int
 pkg syscall (openbsd-amd64-cgo), const EFER_SCE = 1
 pkg syscall (openbsd-amd64-cgo), const EFER_SCE ideal-int
+pkg syscall (openbsd-amd64-cgo), const ImplementsGetwd = false
 pkg syscall (openbsd-amd64-cgo), const PMC5_PIPELINE_FLUSH = 21
 pkg syscall (openbsd-amd64-cgo), const PMC5_PIPELINE_FLUSH ideal-int
 pkg syscall (openbsd-amd64-cgo), const RTF_FMASK = 63496