1 files changed, 197 insertions, 0 deletions
diff --git a/tools/windowsconstgen.go b/tools/windowsconstgen.go
new file mode 100644
index 0000000..448b549
--- /dev/null
+++ b/tools/windowsconstgen.go
@@ -0,0 +1,197 @@
+// 24 may 2014
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"go/token"
+	"go/ast"
+	"go/parser"
+	"sort"
+	"io/ioutil"
+	"path/filepath"
+	"os/exec"
+)
+
+func getPackage(path string) (pkg *ast.Package) {
+	fileset := token.NewFileSet()		// parser.ParseDir() actually writes to this; not sure why it doesn't return one instead
+	filter := func(i os.FileInfo) bool {
+		return strings.HasSuffix(i.Name(), "_windows.go")
+	}
+	pkgs, err := parser.ParseDir(fileset, path, filter, parser.AllErrors)
+	if err != nil {
+		panic(err)
+	}
+	if len(pkgs) != 1 {
+		panic("more than one package found")
+	}
+	for k, _ := range pkgs {		// get the sole key
+		pkg = pkgs[k]
+	}
+	return pkg
+}
+
+type walker struct {
+	desired	func(string) bool
+}
+
+var known = map[string]string{}
+var unknown = map[string]struct{}{}
+
+func (w *walker) Visit(node ast.Node) ast.Visitor {
+	if n, ok := node.(*ast.Ident); ok {
+		if w.desired(n.Name) {
+			if n.Obj != nil {
+				delete(unknown, n.Name)
+				kind := n.Obj.Kind.String()
+				if known[n.Name] != "" && known[n.Name] != kind {
+					panic(n.Name + "(" + kind + ") already known to be a " + known[n.Name])
+				}
+				known[n.Name] = kind
+			} else if _, ok := known[n.Name]; !ok {		// only if not known
+				unknown[n.Name] = struct{}{}
+			}
+		}
+	}
+	return w
+}
+
+func gatherNames(pkg *ast.Package) {
+	desired := func(name string) bool {
+		if strings.HasPrefix(name, "_") && len(name) > 1 {
+			return !strings.ContainsAny(name,
+				"abcdefghijklmnopqrstuvwxyz")
+		}
+		return false
+	}
+	for _, f := range pkg.Files {
+		for _, d := range f.Decls {
+			ast.Walk(&walker{desired}, d)
+		}
+	}
+}
+
+// some constants confuse cgo into thinking they're external symbols for some reason
+// fortunately all these constants are pointers
+// TODO debug cgo
+var hacknames = map[string]string{
+	"_INVALID_HANDLE_VALUE":		"x_INVALID_HANDLE_VALUE",
+	"_NULL":						"x_NULL",
+	"_IDI_APPLICATION":			"x_IDI_APPLICATION",
+	"_IDC_ARROW":				"x_IDC_ARROW",
+	"_HWND_MESSAGE":			"x_HWND_MESSAGE",
+}
+
+func hacknamesPreamble() string {
+	if len(hacknames) == 0 {
+		return ""
+	}
+	// keep sorted for git
+	hn := make([]string, 0, len(hacknames))
+	for origname, _ := range hacknames {
+		hn = append(hn, origname)
+	}
+	sort.Strings(hn)
+	s := "// /* because cgo has issues with these */\n"
+	s += "// #include <stdint.h>\n"
+	for _, origname := range hn {
+		s += "// uintptr_t " + hacknames[origname] + " = (uintptr_t) (" +
+			origname[1:] + ");\n"		// strip leading _
+	}
+	return s
+}
+
+func preamble(pkg string) string {
+	return "// autogenerated by windowsconstgen; do not edit\n" +
+		"package " + pkg + "\n"
+}
+
+func main() {
+	if len(os.Args) < 3 {
+		panic("usage: " + os.Args[0] + " path goarch [go-command-options...]")
+	}
+	pkgpath := os.Args[1]
+	targetarch := os.Args[2]
+	goopts := os.Args[3:]		// valid if len(os.Args) == 3; in that case this will just be a slice of length zero
+
+	pkg := getPackage(pkgpath)
+	gatherNames(pkg)
+
+	// if we still have some known, I didn't clean things up completely
+	knowns := ""
+	for ident, kind := range known {
+		if kind != "var" && kind != "const" {
+			continue
+		}
+		knowns += "\n" + ident + " (" + kind + ")"
+	}
+	if knowns != "" {
+		panic("error: the following are still known!" + knowns)		// has a newline already
+	}
+
+	// keep sorted for git
+	consts := make([]string, 0, len(unknown))
+	for ident, _ := range unknown {
+		if hackname, ok := hacknames[ident]; ok {
+			consts = append(consts, hackname)
+			continue
+		}
+		consts = append(consts, ident)
+	}
+	sort.Strings(consts)
+
+	// thanks to james4k in irc.freenode.net/#go-nuts
+	tmpdir, err := ioutil.TempDir("", "windowsconstgen")
+	if err != nil {
+		panic(err)
+	}
+	genoutname := filepath.Join(tmpdir, "gen.go")
+	f, err := os.Create(genoutname)
+	if err != nil {
+		panic(err)
+	}
+	fmt.Fprintf(f, "%s" +
+		"import \"fmt\"\n" +
+		"// #include <windows.h>\n" +
+		"// #include <commctrl.h>\n" +
+		"%s" +
+		"import \"C\"\n" +
+		"func main() {\n" +
+		"	fmt.Print(%q)\n",
+		preamble("main"), hacknamesPreamble(), preamble("ui"))
+	for _, ident := range consts {
+		if ident[0] == 'x' {
+			// hack name; strip the leading x (but not the _ after it) from the constant name but keep the value name unchanged
+			fmt.Fprintf(f, "	fmt.Println(\"const %s =\", C.%s)\n", ident[1:], ident)
+			continue
+		}
+		// not a hack name; strip the leading _ from the value name but keep the constant name unchanged
+		fmt.Fprintf(f, "	fmt.Println(\"const %s =\", C.%s)\n", ident, ident[1:])
+	}
+	fmt.Fprintf(f, "}\n")
+	f.Close()
+
+	cmd := exec.Command("go", "run")
+	cmd.Args = append(cmd.Args, goopts...)		// valid if len(goopts) == 0; in that case this will just be a no-op
+	cmd.Args = append(cmd.Args, genoutname)
+	f, err = os.Create(filepath.Join(pkgpath, "zconstants_windows_" + targetarch + ".go"))
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+	cmd.Stdout = f
+	cmd.Stderr = os.Stderr
+	cmd.Env = append(cmd.Env, os.Environ()...)		// otherwise $PATH doesn't get carried over and things mysteriously fail
+	cmd.Env = append(cmd.Env,
+		"GOOS=windows",
+		"GOARCH=" + targetarch,
+		"CGO_ENABLED=1")		// needed as it's not set by default in cross-compiles
+	err = cmd.Run()
+	if err != nil {
+		// TODO find a way to get the exit code
+		os.Exit(1)
+	}
+
+	// TODO remove the temporary directory
+}