generate the instruction table

internal/cmd/avogen/main.go

@@ -11,9 +11,9 @@ import (
 	"github.com/mmcloughlin/avo/internal/load"
 )
 
-var generators = map[string]gen.Interface{
-	"asmtest": gen.NewAsmTest(),
-	"godata":  gen.NewGoData(),
+var generators = map[string]gen.Builder{
+	"asmtest": gen.NewAsmTest,
+	"godata":  gen.NewGoData,
 }
 
 var datadir = flag.String(
@@ -29,18 +29,23 @@ func main() {
 
 	// Build generator.
 	t := flag.Arg(0)
-	g := generators[t]
-	if g == nil {
+	builder := generators[t]
+	if builder == nil {
 		log.Fatalf("unknown generator type '%s'", t)
 	}
 
+	g := builder(gen.Config{
+		Argv: os.Args,
+	})
+
 	// Determine output writer.
 	w := os.Stdout
 	if *output != "" {
-		f, err := os.Open(*output)
+		f, err := os.Create(*output)
 		if err != nil {
 			log.Fatal(err)
 		}
+		defer f.Close()
 		w = f
 	}
 

internal/gen/asmtest.go

@@ -10,18 +10,21 @@ import (
 )
 
 type asmtest struct {
+	cfg   Config
 	sym   string // reference to the test function symbol
 	rel8  string // label to be used for near jumps
 	rel32 string // label for far jumps
 }
 
-func NewAsmTest() Interface {
-	return &asmtest{}
+func NewAsmTest(cfg Config) Interface {
+	return &asmtest{cfg: cfg}
 }
 
 func (a *asmtest) Generate(is []*inst.Instruction) ([]byte, error) {
 	p := &printer{}
 
+	p.Printf("# %s\n\n", a.cfg.GeneratedWarning())
+
 	a.sym = "\u00b7loadertest(SB)"
 	p.Printf("TEXT %s, 0, $0\n", a.sym)
 

internal/gen/gen.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"go/format"
+	"strings"
 
 	"github.com/mmcloughlin/avo/internal/inst"
 )
@@ -18,6 +19,24 @@ func (f Func) Generate(is []*inst.Instruction) ([]byte, error) {
 	return f(is)
 }
 
+type Config struct {
+	Name string
+	Argv []string
+}
+
+func (c Config) GeneratedBy() string {
+	if c.Argv == nil {
+		return c.Name
+	}
+	return fmt.Sprintf("command: %s", strings.Join(c.Argv, " "))
+}
+
+func (c Config) GeneratedWarning() string {
+	return fmt.Sprintf("Code generated by %s. DO NOT EDIT.", c.GeneratedBy())
+}
+
+type Builder func(Config) Interface
+
 // GoFmt formats Go code produced from the given generator.
 func GoFmt(i Interface) Interface {
 	return Func(func(is []*inst.Instruction) ([]byte, error) {

internal/gen/gen_test.go

@@ -0,0 +1,8 @@
+package gen
+
+import "testing"
+
+func TestBuilderInterfaces(t *testing.T) {
+	var _ Builder = NewAsmTest
+	var _ Builder = NewGoData
+}

internal/gen/godata.go

@@ -5,15 +5,17 @@ import (
 )
 
 type godata struct {
+	cfg Config
 }
 
-func NewGoData() Interface {
-	return GoFmt(godata{})
+func NewGoData(cfg Config) Interface {
+	return GoFmt(godata{cfg: cfg})
 }
 
 func (g godata) Generate(is []*inst.Instruction) ([]byte, error) {
 	p := &printer{}
 
+	p.Printf("// %s\n\n", g.cfg.GeneratedWarning())
 	p.Printf("package inst\n\n")
 
 	p.Printf("var Instructions = []Instruction{\n")

internal/inst/types.go

@@ -1,5 +1,7 @@
 package inst
 
+//go:generate avogen -data ../data -output ztable.go godata
+
 type Instruction struct {
 	Opcode  string
 	Summary string

internal/load/load.go

@@ -2,6 +2,7 @@ package load
 
 import (
 	"path/filepath"
+	"sort"
 	"strconv"
 	"strings"
 
@@ -61,12 +62,16 @@ func (l *Loader) Load() ([]*inst.Instruction, error) {
 		}
 	}
 
-	// Convert to a slice to return.
+	// Convert to a slice, sorted by opcode.
 	is := make([]*inst.Instruction, 0, len(im))
 	for _, i := range im {
 		is = append(is, i)
 	}
 
+	sort.Slice(is, func(i, j int) bool {
+		return is[i].Opcode < is[j].Opcode
+	})
+
 	return is, nil
 }