8 files changed, 152 insertions, 6 deletions
diff --git a/src/pkg/Makefile b/src/pkg/Makefile
index e833fcfbba..321b463b13 100644
--- a/src/pkg/Makefile
+++ b/src/pkg/Makefile
@@ -68,7 +68,6 @@ DIRS=\
 	debug/elf\
 	debug/gosym\
 	debug/pe\
-	ebnf\
 	encoding/ascii85\
 	encoding/base32\
 	encoding/base64\
@@ -78,6 +77,8 @@ DIRS=\
 	encoding/pem\
 	exec\
 	exp/datafmt\
+	exp/ebnf\
+	exp/ebnflint\
 	exp/gui\
 	exp/gui/x11\
 	exp/norm\
@@ -173,7 +174,6 @@ DIRS=\
 	websocket\
 	xml\
 	../cmd/cgo\
-	../cmd/ebnflint\
 	../cmd/godoc\
 	../cmd/gofix\
 	../cmd/gofmt\
@@ -201,6 +201,7 @@ NOTEST+=\
 	crypto\
 	crypto/openpgp/error\
 	crypto/x509/pkix\
+	exp/ebnflint\
 	exp/gui\
 	exp/gui/x11\
 	exp/sql/driver\
@@ -220,7 +221,6 @@ NOTEST+=\
 	testing\
 	testing/iotest\
 	../cmd/cgo\
-	../cmd/ebnflint\
 	../cmd/godoc\
 	../cmd/gotest\
 	../cmd/goyacc\
diff --git a/src/pkg/ebnf/Makefile b/src/pkg/exp/ebnf/Makefile
index f5555d2720..844de675cb 100644
--- a/src/pkg/ebnf/Makefile
+++ b/src/pkg/exp/ebnf/Makefile
@@ -2,11 +2,11 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 
-include ../../Make.inc
+include ../../../Make.inc
 
-TARG=ebnf
+TARG=exp/ebnf
 GOFILES=\
 	ebnf.go\
 	parser.go\
 
-include ../../Make.pkg
+include ../../../Make.pkg
diff --git a/src/pkg/ebnf/ebnf.go b/src/pkg/exp/ebnf/ebnf.go
index 2ec7f00800..2ec7f00800 100644
--- a/src/pkg/ebnf/ebnf.go
+++ b/src/pkg/exp/ebnf/ebnf.go
diff --git a/src/pkg/ebnf/ebnf_test.go b/src/pkg/exp/ebnf/ebnf_test.go
index 8cfd6b9c37..8cfd6b9c37 100644
--- a/src/pkg/ebnf/ebnf_test.go
+++ b/src/pkg/exp/ebnf/ebnf_test.go
diff --git a/src/pkg/ebnf/parser.go b/src/pkg/exp/ebnf/parser.go
index 2dbbefb751..2dbbefb751 100644
--- a/src/pkg/ebnf/parser.go
+++ b/src/pkg/exp/ebnf/parser.go
diff --git a/src/pkg/exp/ebnflint/Makefile b/src/pkg/exp/ebnflint/Makefile
new file mode 100644
index 0000000000..2057b07d58
--- /dev/null
+++ b/src/pkg/exp/ebnflint/Makefile
@@ -0,0 +1,15 @@
+# Copyright 2009 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+include ../../../Make.inc
+
+TARG=ebnflint
+GOFILES=\
+	ebnflint.go\
+
+include ../../../Make.cmd
+
+test: $(TARG)
+	$(TARG) -start="SourceFile" "$(GOROOT)"/doc/go_spec.html
+
diff --git a/src/pkg/exp/ebnflint/doc.go b/src/pkg/exp/ebnflint/doc.go
new file mode 100644
index 0000000000..f35976eea7
--- /dev/null
+++ b/src/pkg/exp/ebnflint/doc.go
@@ -0,0 +1,22 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+
+Ebnflint verifies that EBNF productions are consistent and gramatically correct.
+It reads them from an HTML document such as the Go specification.
+
+Grammar productions are grouped in boxes demarcated by the HTML elements
+	<pre class="ebnf">
+	</pre>
+
+
+Usage:
+	ebnflint [--start production] [file]
+
+The --start flag specifies the name of the start production for
+the grammar; it defaults to "Start".
+
+*/
+package documentation
diff --git a/src/pkg/exp/ebnflint/ebnflint.go b/src/pkg/exp/ebnflint/ebnflint.go
new file mode 100644
index 0000000000..c827716c44
--- /dev/null
+++ b/src/pkg/exp/ebnflint/ebnflint.go
@@ -0,0 +1,109 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"bytes"
+	"exp/ebnf"
+	"flag"
+	"fmt"
+	"go/scanner"
+	"go/token"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+)
+
+var fset = token.NewFileSet()
+var start = flag.String("start", "Start", "name of start production")
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "usage: ebnflint [flags] [filename]\n")
+	flag.PrintDefaults()
+	os.Exit(1)
+}
+
+// Markers around EBNF sections in .html files
+var (
+	open  = []byte(`<pre class="ebnf">`)
+	close = []byte(`</pre>`)
+)
+
+func report(err os.Error) {
+	scanner.PrintError(os.Stderr, err)
+	os.Exit(1)
+}
+
+func extractEBNF(src []byte) []byte {
+	var buf bytes.Buffer
+
+	for {
+		// i = beginning of EBNF text
+		i := bytes.Index(src, open)
+		if i < 0 {
+			break // no EBNF found - we are done
+		}
+		i += len(open)
+
+		// write as many newlines as found in the excluded text
+		// to maintain correct line numbers in error messages
+		for _, ch := range src[0:i] {
+			if ch == '\n' {
+				buf.WriteByte('\n')
+			}
+		}
+
+		// j = end of EBNF text (or end of source)
+		j := bytes.Index(src[i:], close) // close marker
+		if j < 0 {
+			j = len(src) - i
+		}
+		j += i
+
+		// copy EBNF text
+		buf.Write(src[i:j])
+
+		// advance
+		src = src[j:]
+	}
+
+	return buf.Bytes()
+}
+
+func main() {
+	flag.Parse()
+
+	var (
+		filename string
+		src      []byte
+		err      os.Error
+	)
+	switch flag.NArg() {
+	case 0:
+		filename = "<stdin>"
+		src, err = ioutil.ReadAll(os.Stdin)
+	case 1:
+		filename = flag.Arg(0)
+		src, err = ioutil.ReadFile(filename)
+	default:
+		usage()
+	}
+	if err != nil {
+		report(err)
+	}
+
+	if filepath.Ext(filename) == ".html" || bytes.Index(src, open) >= 0 {
+		src = extractEBNF(src)
+	}
+
+	grammar, err := ebnf.Parse(filename, bytes.NewBuffer(src))
+	if err != nil {
+		report(err)
+	}
+
+	if err = ebnf.Verify(grammar, *start); err != nil {
+		report(err)
+	}
+}