Add a go.mod for v1.1.0. This will make the Go proxy (#86)

prefer v1.* (with a valid go.mod file) over the v2.1.0+incompatible version
(which doesn't have a go.mod file).

.appveyor/install.sh

@@ -6,9 +6,11 @@ export GOROOT=/mingw64/lib/go
 export GOPATH=/go
 export CGO_ENABLED=1
 
+set -x
+
 pacman --noconfirm -S \
-    mingw64/mingw-w64-x86_64-go \
-    mingw64/mingw-w64-x86_64-libusb
+    mingw-w64-x86_64-go \
+    mingw-w64-x86_64-libusb
 
 go version
 go get -t github.com/google/gousb/...

.appveyor/upgrade_pacman.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+export PATH="/mingw64/bin:${PATH}"
+set -x
+curl -O https://repo.msys2.org/msys/x86_64/msys2-keyring-r21.b39fb11-1-any.pkg.tar.xz
+curl -O https://repo.msys2.org/msys/x86_64/msys2-keyring-r21.b39fb11-1-any.pkg.tar.xz.sig
+pacman-key --verify msys2-keyring-r21.b39fb11-1-any.pkg.tar.xz.sig &&\
+pacman --noconfirm -U msys2-keyring-r21.b39fb11-1-any.pkg.tar.xz
+pacman --noconfirm -Syy pacman

appveyor.yml

@@ -3,6 +3,7 @@ platform: x64
 clone_folder: C:\msys64\go\src\github.com\google\gousb
 
 install:
-  - C:\msys64\usr\bin\bash.exe -lc "cd /go/src/github.com/google/gousb/ && .appveyor/./install.sh"
+  - C:\msys64\usr\bin\bash.exe -l /go/src/github.com/google/gousb/.appveyor/upgrade_pacman.sh
+  - C:\msys64\usr\bin\bash.exe -lc "cd /go/src/github.com/google/gousb/ && .appveyor/install.sh"
 
 build: off

fakelibusb_test.go

@@ -98,7 +98,7 @@ type fakeLibusb struct {
 	claims map[*libusbDevice]map[uint8]bool
 }
 
-func (f *fakeLibusb) init() (*libusbContext, error)                       { return new(libusbContext), nil }
+func (f *fakeLibusb) init() (*libusbContext, error)                       { return newContextPointer(), nil }
 func (f *fakeLibusb) handleEvents(c *libusbContext, done <-chan struct{}) { <-done }
 func (f *fakeLibusb) getDevices(*libusbContext) ([]*libusbDevice, error) {
 	ret := make([]*libusbDevice, 0, len(fakeDevices))
@@ -128,7 +128,7 @@ func (f *fakeLibusb) getDeviceDesc(d *libusbDevice) (*DeviceDesc, error) {
 	return nil, fmt.Errorf("invalid USB device %p", d)
 }
 func (f *fakeLibusb) open(d *libusbDevice) (*libusbDevHandle, error) {
-	h := new(libusbDevHandle)
+	h := newDevHandlePointer()
 	f.mu.Lock()
 	defer f.mu.Unlock()
 	f.handles[h] = d

go.mod

@@ -0,0 +1,3 @@
+module github.com/google/gousb
+
+go 1.13

libusb.go

@@ -508,6 +508,7 @@ func libusbSetDebug(c *libusbContext, lvl int) {
 	C.gousb_set_debug((*C.libusb_context)(c), C.int(lvl))
 }
 
+// for obtaining unique CGo pointers.
 func newDevicePointer() *libusbDevice {
 	return (*libusbDevice)(unsafe.Pointer(C.malloc(1)))
 }
@@ -515,3 +516,11 @@ func newDevicePointer() *libusbDevice {
 func newFakeTransferPointer() *libusbTransfer {
 	return (*libusbTransfer)(unsafe.Pointer(C.malloc(1)))
 }
+
+func newContextPointer() *libusbContext {
+	return (*libusbContext)(unsafe.Pointer(C.malloc(1)))
+}
+
+func newDevHandlePointer() *libusbDevHandle {
+	return (*libusbDevHandle)(unsafe.Pointer(C.malloc(1)))
+}