pkg/ast: new parser for sys descriptions

The old parser in sys/sysparser is too hacky, difficult to extend
and drops debug info too early, so that we can't produce proper error messages.

Add a new parser that is build like a proper language parser
and preserves full debug info for every token.

1 files changed, 72 insertions, 0 deletions

diff --git a/tools/syz-fmt/syz-fmt.go b/tools/syz-fmt/syz-fmt.go
new file mode 100644
index 000000000..f78e8b8dc
--- /dev/null
+++ b/tools/syz-fmt/syz-fmt.go
@@ -0,0 +1,72 @@
+// Copyright 2017 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+// syz-fmt re-formats sys files into standard form.
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/google/syzkaller/pkg/ast"
+)
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Fprintf(os.Stderr, "usage: syz-fmt files... or dirs...\n")
+		os.Exit(1)
+	}
+	for _, arg := range os.Args[1:] {
+		st, err := os.Stat(arg)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "failed to stat %v: %v\n", arg, err)
+			os.Exit(1)
+		}
+		if st.IsDir() {
+			files, err := ioutil.ReadDir(arg)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "failed to read dir %v: %v\n", arg, err)
+				os.Exit(1)
+			}
+			for _, file := range files {
+				if !strings.HasSuffix(file.Name(), ".txt") {
+					continue
+				}
+				processFile(filepath.Join(arg, file.Name()), file.Mode())
+			}
+		} else {
+			processFile(arg, st.Mode())
+		}
+	}
+}
+
+func processFile(file string, mode os.FileMode) {
+	data, err := ioutil.ReadFile(file)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "failed to read file %v: %v\n", file, err)
+		os.Exit(1)
+	}
+	errorHandler := func(pos ast.Pos, msg string) {
+		fmt.Fprintf(os.Stderr, "%v:%v:%v: %v", pos.File, pos.Line, pos.Col, msg)
+	}
+	top, ok := ast.Parse(data, filepath.Base(file), errorHandler)
+	if !ok {
+		os.Exit(1)
+	}
+	formatted := ast.Format(top)
+	if bytes.Equal(data, formatted) {
+		return
+	}
+	if err := os.Rename(file, file+"~"); err != nil {
+		fmt.Fprintf(os.Stderr, "%v\n", err)
+		os.Exit(1)
+	}
+	if err := ioutil.WriteFile(file, formatted, mode); err != nil {
+		fmt.Fprintf(os.Stderr, "%v\n", err)
+		os.Exit(1)
+	}
+}