Added incomplete code for a program that generates a set of Windows constants using cgo.

experiments/windowsconstgen.go

@@ -0,0 +1,83 @@
+// 24 may 2014
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"go/token"
+	"go/ast"
+	"go/parser"
+)
+
+func main() {
+	var pkg *ast.Package
+
+	importpath := os.Args[1]
+
+	fileset := token.NewFileSet()
+
+	filter := func(i os.FileInfo) bool {
+		return strings.HasSuffix(i.Name(), "_windows.go")
+	}
+	pkgs, err := parser.ParseDir(fileset, importpath,
+		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]
+	}
+
+	var run func(...ast.Decl)
+	var runstmt func(ast.Stmt)
+	var runblock func(*ast.BlockStmt)
+
+	desired := func(name string) bool {
+		return strings.HasPrefix(name, "_")
+	}
+	run = func(decls ...ast.Decl) {
+		for _, d := range decls {
+			switch dd := d.(type) {
+			case *ast.FuncDecl:
+				runblock(dd.Body)
+			case *ast.GenDecl:
+				if desired(d.Name.String()) {
+					fmt.Println(d.Name.String())
+				}
+			default:
+				panic(fmt.Errorf("unknown decl type %T: %v", dd, dd))
+			}
+		}
+	}
+	runstmt = func(s ast.Stmt) {
+		switch ss := s.(type) {
+		case *ast.DeclStmt:
+			run(ss.Decl)
+		case *ast.LabeledStmt:
+			runstmt(ss.Stmt)
+		case *ast.AssignStmt:
+			// TODO go through Lhs if ss.Tok type == DEFINE
+		case *ast.GoStmt:
+		// these don't have decls
+		case *ast.EmptyStmt:
+		case *ast.ExprStmt:
+		case *ast.SendStmt:
+		case *ast.IncDecStmt:
+			// all do nothing
+		default:
+			panic(fmt.Errorf("unknown stmt type %T: %v", dd, dd))
+		}
+	}
+	runblock = func(block *ast.BlockStmt) {
+		for _, s := range block.Stmt {
+			runstmt(s)
+		}
+	}
+	for _, f := range pkg.Files {
+		run(f.Decls...)
+	}
+}