Generate the remaining consts. (#55)

* Generate the remaining consts.

There were a number of hand-written consts in go-libvirt, including flag
values for various libvirt functions. Remove these and generate them
instead, so that we now have a complete set, and the naming is
consistent. I used c-for-go to do this generation, but turned off any
cgo usage by the generated code - we don't want or need to introduce a
dependency on cgo just to get constants from C headers. All code is
still generated using 'go generate ./...', which now calls a wrapper
script for added robustness.

This change also returns to using Go types for flags for most libvirt
functions, instead of plain integers.

scripts/gen-consts.sh

@@ -0,0 +1,40 @@
+#!/bin/bash
+#
+# This runs the first code generator used by go-libvirt: c-for-go. This script
+# is run from the 'go generate ./...' command, and only needs to be run when
+# changing to a different version of libvirt.
+if [ -z "${LIBVIRT_SOURCE}" ]; then
+    echo "Set LIBVIRT_SOURCE to the root of the libvirt sources you want to use first."
+    exit 1
+fi
+
+# Make sure c-for-go is installed
+if ! which c-for-go > /dev/null; then
+    echo "c-for-go not found. Attempting to install it..."
+    if ! go get github.com/xlab/c-for-go/...; then
+        echo "failed to install c-for-go. Please install it manually from https://github.com/xlab/c-for-go"
+        exit 1
+    fi
+fi
+
+# Make sure goyacc is installed (needed for the lvgen/ generator)
+if ! which goyacc > /dev/null; then
+    echo "goyacc not found. Attempting to install it..."
+    if ! go get golang.org/x/tools/cmd/goyacc/...; then
+        echo "failed to install goyacc. Please install it manually from https://golang.org/x/tools/cmd/goyacc"
+        exit 1
+    fi
+fi
+
+# Temporarily symlink the libvirt sources to a subdirectory because c-for-go
+# lacks a mechanism for us to pass it a search path for header files.
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+LVDIR=lv_source
+ln -sF ${LIBVIRT_SOURCE} ${LVDIR}
+if ! c-for-go -nostamp -nocgo -ccincl libvirt.yml; then
+    echo "c-for-go failed"
+    exit 1
+fi
+mv libvirt/const.go ${DIR}/../const.gen.go
+rm ${LVDIR}
+rm -rf libvirt/

scripts/licensecheck.sh

@@ -18,7 +18,6 @@ read -r -d '' EXPECTED <<EndOfLicense
 // limitations under the License.
 EndOfLicense
 
-# Scan each Go source file for license.
 EXIT=0
 GOFILES=$(find . -name "*.go")