operand: const types

operand/make_const.go

@@ -0,0 +1,75 @@
+// +build ignore
+
+package main
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"go/format"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strconv"
+)
+
+var (
+	output = flag.String("output", "", "path to output file (default stdout)")
+)
+
+func PrintConstType(w io.Writer, name, typ, format string, size int, doc string) {
+	r := typ[0]
+	fmt.Fprintf(w, "// %s\n", doc)
+	fmt.Fprintf(w, "type %s %s\n", name, typ)
+	fmt.Fprintf(w, "\n")
+	fmt.Fprintf(w, "func (%c %s) Asm() string { return fmt.Sprintf(\"$%s\", %c) }\n", r, name, format, r)
+	fmt.Fprintf(w, "func (%c %s) Bytes() int  { return %d }\n", r, name, size)
+	fmt.Fprintf(w, "func (%c %s) constant()   {}\n", r, name)
+	fmt.Fprintf(w, "\n")
+}
+
+func PrintConstTypes(w io.Writer) {
+	_, self, _, _ := runtime.Caller(0)
+	fmt.Fprintf(w, "// Code generated by %s. DO NOT EDIT.\n\n", filepath.Base(self))
+	fmt.Fprintf(w, "package operand\n\n")
+	fmt.Fprintf(w, "import \"fmt\"\n\n")
+	for n := 1; n <= 8; n *= 2 {
+		bits := n * 8
+		bs := strconv.Itoa(bits)
+
+		if n >= 4 {
+			PrintConstType(w, "F"+bs, "float"+bs, "(%#v)", n, fmt.Sprintf("F%d is a %d-bit floating point constant.", bits, bits))
+		}
+		PrintConstType(w, "I"+bs, "int"+bs, "%+d", n, fmt.Sprintf("I%d is a %d-bit signed integer constant.", bits, bits))
+		PrintConstType(w, "U"+bs, "uint"+bs, "%#0"+strconv.Itoa(2*n)+"x", n, fmt.Sprintf("U%d is a %d-bit unsigned integer constant.", bits, bits))
+	}
+}
+
+func main() {
+	flag.Parse()
+
+	w := os.Stdout
+	if *output != "" {
+		f, err := os.Create(*output)
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer f.Close()
+		w = f
+	}
+
+	buf := bytes.NewBuffer(nil)
+	PrintConstTypes(buf)
+
+	src, err := format.Source(buf.Bytes())
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	_, err = w.Write(src)
+	if err != nil {
+		log.Fatal(err)
+	}
+}