dd931d9b48
Reviewed-on: https://go-review.googlesource.com/136435 gotools/: * Makefile.am (mostlyclean-local): Run chmod on check-go-dir to make sure it is writable. (check-go-tools): Likewise. (check-vet): Copy internal/objabi to check-vet-dir. * Makefile.in: Rebuild. From-SVN: r264546
593 lines
15 KiB
Go
593 lines
15 KiB
Go
// Copyright 2011 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package template
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import (
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"bytes"
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"strings"
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)
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// transitionFunc is the array of context transition functions for text nodes.
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// A transition function takes a context and template text input, and returns
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// the updated context and the number of bytes consumed from the front of the
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// input.
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var transitionFunc = [...]func(context, []byte) (context, int){
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stateText: tText,
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stateTag: tTag,
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stateAttrName: tAttrName,
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stateAfterName: tAfterName,
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stateBeforeValue: tBeforeValue,
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stateHTMLCmt: tHTMLCmt,
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stateRCDATA: tSpecialTagEnd,
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stateAttr: tAttr,
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stateURL: tURL,
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stateSrcset: tURL,
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stateJS: tJS,
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stateJSDqStr: tJSDelimited,
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stateJSSqStr: tJSDelimited,
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stateJSRegexp: tJSDelimited,
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stateJSBlockCmt: tBlockCmt,
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stateJSLineCmt: tLineCmt,
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stateCSS: tCSS,
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stateCSSDqStr: tCSSStr,
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stateCSSSqStr: tCSSStr,
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stateCSSDqURL: tCSSStr,
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stateCSSSqURL: tCSSStr,
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stateCSSURL: tCSSStr,
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stateCSSBlockCmt: tBlockCmt,
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stateCSSLineCmt: tLineCmt,
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stateError: tError,
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}
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var commentStart = []byte("<!--")
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var commentEnd = []byte("-->")
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// tText is the context transition function for the text state.
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func tText(c context, s []byte) (context, int) {
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k := 0
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for {
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i := k + bytes.IndexByte(s[k:], '<')
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if i < k || i+1 == len(s) {
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return c, len(s)
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} else if i+4 <= len(s) && bytes.Equal(commentStart, s[i:i+4]) {
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return context{state: stateHTMLCmt}, i + 4
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}
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i++
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end := false
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if s[i] == '/' {
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if i+1 == len(s) {
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return c, len(s)
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}
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end, i = true, i+1
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}
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j, e := eatTagName(s, i)
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if j != i {
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if end {
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e = elementNone
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}
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// We've found an HTML tag.
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return context{state: stateTag, element: e}, j
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}
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k = j
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}
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}
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var elementContentType = [...]state{
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elementNone: stateText,
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elementScript: stateJS,
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elementStyle: stateCSS,
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elementTextarea: stateRCDATA,
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elementTitle: stateRCDATA,
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}
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// tTag is the context transition function for the tag state.
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func tTag(c context, s []byte) (context, int) {
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// Find the attribute name.
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i := eatWhiteSpace(s, 0)
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if i == len(s) {
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return c, len(s)
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}
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if s[i] == '>' {
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return context{
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state: elementContentType[c.element],
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element: c.element,
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}, i + 1
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}
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j, err := eatAttrName(s, i)
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if err != nil {
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return context{state: stateError, err: err}, len(s)
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}
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state, attr := stateTag, attrNone
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if i == j {
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return context{
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state: stateError,
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err: errorf(ErrBadHTML, nil, 0, "expected space, attr name, or end of tag, but got %q", s[i:]),
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}, len(s)
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}
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attrName := strings.ToLower(string(s[i:j]))
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if c.element == elementScript && attrName == "type" {
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attr = attrScriptType
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} else {
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switch attrType(attrName) {
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case contentTypeURL:
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attr = attrURL
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case contentTypeCSS:
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attr = attrStyle
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case contentTypeJS:
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attr = attrScript
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case contentTypeSrcset:
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attr = attrSrcset
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}
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}
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if j == len(s) {
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state = stateAttrName
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} else {
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state = stateAfterName
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}
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return context{state: state, element: c.element, attr: attr}, j
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}
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// tAttrName is the context transition function for stateAttrName.
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func tAttrName(c context, s []byte) (context, int) {
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i, err := eatAttrName(s, 0)
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if err != nil {
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return context{state: stateError, err: err}, len(s)
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} else if i != len(s) {
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c.state = stateAfterName
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}
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return c, i
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}
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// tAfterName is the context transition function for stateAfterName.
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func tAfterName(c context, s []byte) (context, int) {
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// Look for the start of the value.
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i := eatWhiteSpace(s, 0)
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if i == len(s) {
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return c, len(s)
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} else if s[i] != '=' {
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// Occurs due to tag ending '>', and valueless attribute.
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c.state = stateTag
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return c, i
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}
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c.state = stateBeforeValue
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// Consume the "=".
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return c, i + 1
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}
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var attrStartStates = [...]state{
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attrNone: stateAttr,
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attrScript: stateJS,
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attrScriptType: stateAttr,
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attrStyle: stateCSS,
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attrURL: stateURL,
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attrSrcset: stateSrcset,
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}
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// tBeforeValue is the context transition function for stateBeforeValue.
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func tBeforeValue(c context, s []byte) (context, int) {
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i := eatWhiteSpace(s, 0)
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if i == len(s) {
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return c, len(s)
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}
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// Find the attribute delimiter.
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delim := delimSpaceOrTagEnd
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switch s[i] {
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case '\'':
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delim, i = delimSingleQuote, i+1
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case '"':
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delim, i = delimDoubleQuote, i+1
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}
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c.state, c.delim = attrStartStates[c.attr], delim
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return c, i
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}
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// tHTMLCmt is the context transition function for stateHTMLCmt.
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func tHTMLCmt(c context, s []byte) (context, int) {
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if i := bytes.Index(s, commentEnd); i != -1 {
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return context{}, i + 3
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}
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return c, len(s)
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}
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// specialTagEndMarkers maps element types to the character sequence that
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// case-insensitively signals the end of the special tag body.
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var specialTagEndMarkers = [...][]byte{
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elementScript: []byte("script"),
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elementStyle: []byte("style"),
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elementTextarea: []byte("textarea"),
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elementTitle: []byte("title"),
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}
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var (
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specialTagEndPrefix = []byte("</")
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tagEndSeparators = []byte("> \t\n\f/")
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)
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// tSpecialTagEnd is the context transition function for raw text and RCDATA
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// element states.
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func tSpecialTagEnd(c context, s []byte) (context, int) {
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if c.element != elementNone {
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if i := indexTagEnd(s, specialTagEndMarkers[c.element]); i != -1 {
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return context{}, i
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}
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}
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return c, len(s)
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}
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// indexTagEnd finds the index of a special tag end in a case insensitive way, or returns -1
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func indexTagEnd(s []byte, tag []byte) int {
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res := 0
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plen := len(specialTagEndPrefix)
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for len(s) > 0 {
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// Try to find the tag end prefix first
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i := bytes.Index(s, specialTagEndPrefix)
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if i == -1 {
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return i
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}
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s = s[i+plen:]
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// Try to match the actual tag if there is still space for it
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if len(tag) <= len(s) && bytes.EqualFold(tag, s[:len(tag)]) {
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s = s[len(tag):]
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// Check the tag is followed by a proper separator
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if len(s) > 0 && bytes.IndexByte(tagEndSeparators, s[0]) != -1 {
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return res + i
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}
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res += len(tag)
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}
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res += i + plen
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}
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return -1
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}
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// tAttr is the context transition function for the attribute state.
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func tAttr(c context, s []byte) (context, int) {
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return c, len(s)
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}
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// tURL is the context transition function for the URL state.
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func tURL(c context, s []byte) (context, int) {
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if bytes.ContainsAny(s, "#?") {
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c.urlPart = urlPartQueryOrFrag
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} else if len(s) != eatWhiteSpace(s, 0) && c.urlPart == urlPartNone {
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// HTML5 uses "Valid URL potentially surrounded by spaces" for
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// attrs: https://www.w3.org/TR/html5/index.html#attributes-1
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c.urlPart = urlPartPreQuery
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}
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return c, len(s)
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}
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// tJS is the context transition function for the JS state.
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func tJS(c context, s []byte) (context, int) {
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i := bytes.IndexAny(s, `"'/`)
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if i == -1 {
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// Entire input is non string, comment, regexp tokens.
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c.jsCtx = nextJSCtx(s, c.jsCtx)
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return c, len(s)
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}
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c.jsCtx = nextJSCtx(s[:i], c.jsCtx)
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switch s[i] {
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case '"':
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c.state, c.jsCtx = stateJSDqStr, jsCtxRegexp
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case '\'':
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c.state, c.jsCtx = stateJSSqStr, jsCtxRegexp
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case '/':
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switch {
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case i+1 < len(s) && s[i+1] == '/':
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c.state, i = stateJSLineCmt, i+1
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case i+1 < len(s) && s[i+1] == '*':
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c.state, i = stateJSBlockCmt, i+1
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case c.jsCtx == jsCtxRegexp:
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c.state = stateJSRegexp
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case c.jsCtx == jsCtxDivOp:
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c.jsCtx = jsCtxRegexp
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default:
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return context{
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state: stateError,
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err: errorf(ErrSlashAmbig, nil, 0, "'/' could start a division or regexp: %.32q", s[i:]),
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}, len(s)
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}
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default:
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panic("unreachable")
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}
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return c, i + 1
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}
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// tJSDelimited is the context transition function for the JS string and regexp
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// states.
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func tJSDelimited(c context, s []byte) (context, int) {
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specials := `\"`
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switch c.state {
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case stateJSSqStr:
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specials = `\'`
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case stateJSRegexp:
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specials = `\/[]`
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}
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k, inCharset := 0, false
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for {
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i := k + bytes.IndexAny(s[k:], specials)
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if i < k {
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break
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}
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switch s[i] {
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case '\\':
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i++
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if i == len(s) {
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return context{
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state: stateError,
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err: errorf(ErrPartialEscape, nil, 0, "unfinished escape sequence in JS string: %q", s),
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}, len(s)
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}
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case '[':
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inCharset = true
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case ']':
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inCharset = false
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default:
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// end delimiter
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if !inCharset {
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c.state, c.jsCtx = stateJS, jsCtxDivOp
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return c, i + 1
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}
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}
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k = i + 1
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}
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if inCharset {
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// This can be fixed by making context richer if interpolation
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// into charsets is desired.
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return context{
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state: stateError,
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err: errorf(ErrPartialCharset, nil, 0, "unfinished JS regexp charset: %q", s),
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}, len(s)
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}
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return c, len(s)
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}
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var blockCommentEnd = []byte("*/")
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// tBlockCmt is the context transition function for /*comment*/ states.
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func tBlockCmt(c context, s []byte) (context, int) {
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i := bytes.Index(s, blockCommentEnd)
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if i == -1 {
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return c, len(s)
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}
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switch c.state {
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case stateJSBlockCmt:
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c.state = stateJS
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case stateCSSBlockCmt:
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c.state = stateCSS
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default:
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panic(c.state.String())
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}
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return c, i + 2
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}
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// tLineCmt is the context transition function for //comment states.
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func tLineCmt(c context, s []byte) (context, int) {
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var lineTerminators string
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var endState state
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switch c.state {
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case stateJSLineCmt:
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lineTerminators, endState = "\n\r\u2028\u2029", stateJS
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case stateCSSLineCmt:
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lineTerminators, endState = "\n\f\r", stateCSS
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// Line comments are not part of any published CSS standard but
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// are supported by the 4 major browsers.
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// This defines line comments as
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// LINECOMMENT ::= "//" [^\n\f\d]*
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// since https://www.w3.org/TR/css3-syntax/#SUBTOK-nl defines
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// newlines:
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// nl ::= #xA | #xD #xA | #xD | #xC
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default:
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panic(c.state.String())
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}
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i := bytes.IndexAny(s, lineTerminators)
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if i == -1 {
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return c, len(s)
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}
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c.state = endState
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// Per section 7.4 of EcmaScript 5 : https://es5.github.com/#x7.4
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// "However, the LineTerminator at the end of the line is not
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// considered to be part of the single-line comment; it is
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// recognized separately by the lexical grammar and becomes part
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// of the stream of input elements for the syntactic grammar."
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return c, i
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}
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// tCSS is the context transition function for the CSS state.
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func tCSS(c context, s []byte) (context, int) {
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// CSS quoted strings are almost never used except for:
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// (1) URLs as in background: "/foo.png"
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// (2) Multiword font-names as in font-family: "Times New Roman"
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// (3) List separators in content values as in inline-lists:
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// <style>
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// ul.inlineList { list-style: none; padding:0 }
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// ul.inlineList > li { display: inline }
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// ul.inlineList > li:before { content: ", " }
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// ul.inlineList > li:first-child:before { content: "" }
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// </style>
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// <ul class=inlineList><li>One<li>Two<li>Three</ul>
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// (4) Attribute value selectors as in a[href="http://example.com/"]
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//
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// We conservatively treat all strings as URLs, but make some
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// allowances to avoid confusion.
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//
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// In (1), our conservative assumption is justified.
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// In (2), valid font names do not contain ':', '?', or '#', so our
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// conservative assumption is fine since we will never transition past
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// urlPartPreQuery.
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// In (3), our protocol heuristic should not be tripped, and there
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// should not be non-space content after a '?' or '#', so as long as
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// we only %-encode RFC 3986 reserved characters we are ok.
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// In (4), we should URL escape for URL attributes, and for others we
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// have the attribute name available if our conservative assumption
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// proves problematic for real code.
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k := 0
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for {
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i := k + bytes.IndexAny(s[k:], `("'/`)
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if i < k {
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return c, len(s)
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}
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switch s[i] {
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case '(':
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// Look for url to the left.
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p := bytes.TrimRight(s[:i], "\t\n\f\r ")
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if endsWithCSSKeyword(p, "url") {
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j := len(s) - len(bytes.TrimLeft(s[i+1:], "\t\n\f\r "))
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switch {
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case j != len(s) && s[j] == '"':
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c.state, j = stateCSSDqURL, j+1
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case j != len(s) && s[j] == '\'':
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c.state, j = stateCSSSqURL, j+1
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default:
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c.state = stateCSSURL
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}
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return c, j
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}
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case '/':
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if i+1 < len(s) {
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switch s[i+1] {
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case '/':
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c.state = stateCSSLineCmt
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return c, i + 2
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case '*':
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c.state = stateCSSBlockCmt
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return c, i + 2
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}
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}
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case '"':
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c.state = stateCSSDqStr
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return c, i + 1
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case '\'':
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c.state = stateCSSSqStr
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return c, i + 1
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}
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k = i + 1
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}
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}
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// tCSSStr is the context transition function for the CSS string and URL states.
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func tCSSStr(c context, s []byte) (context, int) {
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var endAndEsc string
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switch c.state {
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case stateCSSDqStr, stateCSSDqURL:
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endAndEsc = `\"`
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case stateCSSSqStr, stateCSSSqURL:
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endAndEsc = `\'`
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case stateCSSURL:
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// Unquoted URLs end with a newline or close parenthesis.
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// The below includes the wc (whitespace character) and nl.
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endAndEsc = "\\\t\n\f\r )"
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default:
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panic(c.state.String())
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}
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k := 0
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for {
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i := k + bytes.IndexAny(s[k:], endAndEsc)
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if i < k {
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c, nread := tURL(c, decodeCSS(s[k:]))
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return c, k + nread
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}
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if s[i] == '\\' {
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i++
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if i == len(s) {
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return context{
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state: stateError,
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err: errorf(ErrPartialEscape, nil, 0, "unfinished escape sequence in CSS string: %q", s),
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}, len(s)
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}
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} else {
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c.state = stateCSS
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return c, i + 1
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}
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c, _ = tURL(c, decodeCSS(s[:i+1]))
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k = i + 1
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}
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}
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|
|
|
// tError is the context transition function for the error state.
|
|
func tError(c context, s []byte) (context, int) {
|
|
return c, len(s)
|
|
}
|
|
|
|
// eatAttrName returns the largest j such that s[i:j] is an attribute name.
|
|
// It returns an error if s[i:] does not look like it begins with an
|
|
// attribute name, such as encountering a quote mark without a preceding
|
|
// equals sign.
|
|
func eatAttrName(s []byte, i int) (int, *Error) {
|
|
for j := i; j < len(s); j++ {
|
|
switch s[j] {
|
|
case ' ', '\t', '\n', '\f', '\r', '=', '>':
|
|
return j, nil
|
|
case '\'', '"', '<':
|
|
// These result in a parse warning in HTML5 and are
|
|
// indicative of serious problems if seen in an attr
|
|
// name in a template.
|
|
return -1, errorf(ErrBadHTML, nil, 0, "%q in attribute name: %.32q", s[j:j+1], s)
|
|
default:
|
|
// No-op.
|
|
}
|
|
}
|
|
return len(s), nil
|
|
}
|
|
|
|
var elementNameMap = map[string]element{
|
|
"script": elementScript,
|
|
"style": elementStyle,
|
|
"textarea": elementTextarea,
|
|
"title": elementTitle,
|
|
}
|
|
|
|
// asciiAlpha reports whether c is an ASCII letter.
|
|
func asciiAlpha(c byte) bool {
|
|
return 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z'
|
|
}
|
|
|
|
// asciiAlphaNum reports whether c is an ASCII letter or digit.
|
|
func asciiAlphaNum(c byte) bool {
|
|
return asciiAlpha(c) || '0' <= c && c <= '9'
|
|
}
|
|
|
|
// eatTagName returns the largest j such that s[i:j] is a tag name and the tag type.
|
|
func eatTagName(s []byte, i int) (int, element) {
|
|
if i == len(s) || !asciiAlpha(s[i]) {
|
|
return i, elementNone
|
|
}
|
|
j := i + 1
|
|
for j < len(s) {
|
|
x := s[j]
|
|
if asciiAlphaNum(x) {
|
|
j++
|
|
continue
|
|
}
|
|
// Allow "x-y" or "x:y" but not "x-", "-y", or "x--y".
|
|
if (x == ':' || x == '-') && j+1 < len(s) && asciiAlphaNum(s[j+1]) {
|
|
j += 2
|
|
continue
|
|
}
|
|
break
|
|
}
|
|
return j, elementNameMap[strings.ToLower(string(s[i:j]))]
|
|
}
|
|
|
|
// eatWhiteSpace returns the largest j such that s[i:j] is white space.
|
|
func eatWhiteSpace(s []byte, i int) int {
|
|
for j := i; j < len(s); j++ {
|
|
switch s[j] {
|
|
case ' ', '\t', '\n', '\f', '\r':
|
|
// No-op.
|
|
default:
|
|
return j
|
|
}
|
|
}
|
|
return len(s)
|
|
}
|