mirror of
https://codeberg.org/forgejo/forgejo.git
synced 2024-11-27 09:11:53 -05:00
343 lines
7.4 KiB
Go
343 lines
7.4 KiB
Go
// Copyright (c) 2017 Couchbase, Inc.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package regexp
|
|
|
|
import (
|
|
"regexp/syntax"
|
|
"unicode"
|
|
|
|
unicode_utf8 "unicode/utf8"
|
|
|
|
"github.com/couchbase/vellum/utf8"
|
|
)
|
|
|
|
type compiler struct {
|
|
sizeLimit uint
|
|
insts prog
|
|
instsPool []inst
|
|
|
|
sequences utf8.Sequences
|
|
rangeStack utf8.RangeStack
|
|
startBytes []byte
|
|
endBytes []byte
|
|
}
|
|
|
|
func newCompiler(sizeLimit uint) *compiler {
|
|
return &compiler{
|
|
sizeLimit: sizeLimit,
|
|
startBytes: make([]byte, unicode_utf8.UTFMax),
|
|
endBytes: make([]byte, unicode_utf8.UTFMax),
|
|
}
|
|
}
|
|
|
|
func (c *compiler) compile(ast *syntax.Regexp) (prog, error) {
|
|
err := c.c(ast)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
inst := c.allocInst()
|
|
inst.op = OpMatch
|
|
c.insts = append(c.insts, inst)
|
|
return c.insts, nil
|
|
}
|
|
|
|
func (c *compiler) c(ast *syntax.Regexp) (err error) {
|
|
if ast.Flags&syntax.NonGreedy > 1 {
|
|
return ErrNoLazy
|
|
}
|
|
|
|
switch ast.Op {
|
|
case syntax.OpEndLine, syntax.OpBeginLine,
|
|
syntax.OpBeginText, syntax.OpEndText:
|
|
return ErrNoEmpty
|
|
case syntax.OpWordBoundary, syntax.OpNoWordBoundary:
|
|
return ErrNoWordBoundary
|
|
case syntax.OpEmptyMatch:
|
|
return nil
|
|
case syntax.OpLiteral:
|
|
for _, r := range ast.Rune {
|
|
if ast.Flags&syntax.FoldCase > 0 {
|
|
next := syntax.Regexp{
|
|
Op: syntax.OpCharClass,
|
|
Flags: ast.Flags & syntax.FoldCase,
|
|
Rune0: [2]rune{r, r},
|
|
}
|
|
next.Rune = next.Rune0[0:2]
|
|
// try to find more folded runes
|
|
for r1 := unicode.SimpleFold(r); r1 != r; r1 = unicode.SimpleFold(r1) {
|
|
next.Rune = append(next.Rune, r1, r1)
|
|
}
|
|
err = c.c(&next)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
} else {
|
|
c.sequences, c.rangeStack, err = utf8.NewSequencesPrealloc(
|
|
r, r, c.sequences, c.rangeStack, c.startBytes, c.endBytes)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
for _, seq := range c.sequences {
|
|
c.compileUtf8Ranges(seq)
|
|
}
|
|
}
|
|
}
|
|
case syntax.OpAnyChar:
|
|
next := syntax.Regexp{
|
|
Op: syntax.OpCharClass,
|
|
Flags: ast.Flags & syntax.FoldCase,
|
|
Rune0: [2]rune{0, unicode.MaxRune},
|
|
}
|
|
next.Rune = next.Rune0[:2]
|
|
return c.c(&next)
|
|
case syntax.OpAnyCharNotNL:
|
|
next := syntax.Regexp{
|
|
Op: syntax.OpCharClass,
|
|
Flags: ast.Flags & syntax.FoldCase,
|
|
Rune: []rune{0, 0x09, 0x0B, unicode.MaxRune},
|
|
}
|
|
return c.c(&next)
|
|
case syntax.OpCharClass:
|
|
return c.compileClass(ast)
|
|
case syntax.OpCapture:
|
|
return c.c(ast.Sub[0])
|
|
case syntax.OpConcat:
|
|
for _, sub := range ast.Sub {
|
|
err := c.c(sub)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
return nil
|
|
case syntax.OpAlternate:
|
|
if len(ast.Sub) == 0 {
|
|
return nil
|
|
}
|
|
jmpsToEnd := make([]uint, 0, len(ast.Sub)-1)
|
|
// does not handle last entry
|
|
for i := 0; i < len(ast.Sub)-1; i++ {
|
|
sub := ast.Sub[i]
|
|
split := c.emptySplit()
|
|
j1 := c.top()
|
|
err := c.c(sub)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
jmpsToEnd = append(jmpsToEnd, c.emptyJump())
|
|
j2 := c.top()
|
|
c.setSplit(split, j1, j2)
|
|
}
|
|
// handle last entry
|
|
err := c.c(ast.Sub[len(ast.Sub)-1])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
end := uint(len(c.insts))
|
|
for _, jmpToEnd := range jmpsToEnd {
|
|
c.setJump(jmpToEnd, end)
|
|
}
|
|
case syntax.OpQuest:
|
|
split := c.emptySplit()
|
|
j1 := c.top()
|
|
err := c.c(ast.Sub[0])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
j2 := c.top()
|
|
c.setSplit(split, j1, j2)
|
|
|
|
case syntax.OpStar:
|
|
j1 := c.top()
|
|
split := c.emptySplit()
|
|
j2 := c.top()
|
|
err := c.c(ast.Sub[0])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
jmp := c.emptyJump()
|
|
j3 := uint(len(c.insts))
|
|
|
|
c.setJump(jmp, j1)
|
|
c.setSplit(split, j2, j3)
|
|
|
|
case syntax.OpPlus:
|
|
j1 := c.top()
|
|
err := c.c(ast.Sub[0])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
split := c.emptySplit()
|
|
j2 := c.top()
|
|
c.setSplit(split, j1, j2)
|
|
|
|
case syntax.OpRepeat:
|
|
if ast.Max == -1 {
|
|
for i := 0; i < ast.Min; i++ {
|
|
err := c.c(ast.Sub[0])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
next := syntax.Regexp{
|
|
Op: syntax.OpStar,
|
|
Flags: ast.Flags,
|
|
Sub: ast.Sub,
|
|
Sub0: ast.Sub0,
|
|
Rune: ast.Rune,
|
|
Rune0: ast.Rune0,
|
|
}
|
|
return c.c(&next)
|
|
}
|
|
for i := 0; i < ast.Min; i++ {
|
|
err := c.c(ast.Sub[0])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
splits := make([]uint, 0, ast.Max-ast.Min)
|
|
starts := make([]uint, 0, ast.Max-ast.Min)
|
|
for i := ast.Min; i < ast.Max; i++ {
|
|
splits = append(splits, c.emptySplit())
|
|
starts = append(starts, uint(len(c.insts)))
|
|
err := c.c(ast.Sub[0])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
end := uint(len(c.insts))
|
|
for i := 0; i < len(splits); i++ {
|
|
c.setSplit(splits[i], starts[i], end)
|
|
}
|
|
|
|
}
|
|
|
|
return c.checkSize()
|
|
}
|
|
|
|
func (c *compiler) checkSize() error {
|
|
if uint(len(c.insts)*instSize) > c.sizeLimit {
|
|
return ErrCompiledTooBig
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (c *compiler) compileClass(ast *syntax.Regexp) error {
|
|
if len(ast.Rune) == 0 {
|
|
return nil
|
|
}
|
|
jmps := make([]uint, 0, len(ast.Rune)-2)
|
|
// does not do last pair
|
|
for i := 0; i < len(ast.Rune)-2; i += 2 {
|
|
rstart := ast.Rune[i]
|
|
rend := ast.Rune[i+1]
|
|
|
|
split := c.emptySplit()
|
|
j1 := c.top()
|
|
err := c.compileClassRange(rstart, rend)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
jmps = append(jmps, c.emptyJump())
|
|
j2 := c.top()
|
|
c.setSplit(split, j1, j2)
|
|
}
|
|
// handle last pair
|
|
rstart := ast.Rune[len(ast.Rune)-2]
|
|
rend := ast.Rune[len(ast.Rune)-1]
|
|
err := c.compileClassRange(rstart, rend)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
end := c.top()
|
|
for _, jmp := range jmps {
|
|
c.setJump(jmp, end)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (c *compiler) compileClassRange(startR, endR rune) (err error) {
|
|
c.sequences, c.rangeStack, err = utf8.NewSequencesPrealloc(
|
|
startR, endR, c.sequences, c.rangeStack, c.startBytes, c.endBytes)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
jmps := make([]uint, 0, len(c.sequences)-1)
|
|
// does not do last entry
|
|
for i := 0; i < len(c.sequences)-1; i++ {
|
|
seq := c.sequences[i]
|
|
split := c.emptySplit()
|
|
j1 := c.top()
|
|
c.compileUtf8Ranges(seq)
|
|
jmps = append(jmps, c.emptyJump())
|
|
j2 := c.top()
|
|
c.setSplit(split, j1, j2)
|
|
}
|
|
// handle last entry
|
|
c.compileUtf8Ranges(c.sequences[len(c.sequences)-1])
|
|
end := c.top()
|
|
for _, jmp := range jmps {
|
|
c.setJump(jmp, end)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (c *compiler) compileUtf8Ranges(seq utf8.Sequence) {
|
|
for _, r := range seq {
|
|
inst := c.allocInst()
|
|
inst.op = OpRange
|
|
inst.rangeStart = r.Start
|
|
inst.rangeEnd = r.End
|
|
c.insts = append(c.insts, inst)
|
|
}
|
|
}
|
|
|
|
func (c *compiler) emptySplit() uint {
|
|
inst := c.allocInst()
|
|
inst.op = OpSplit
|
|
c.insts = append(c.insts, inst)
|
|
return c.top() - 1
|
|
}
|
|
|
|
func (c *compiler) emptyJump() uint {
|
|
inst := c.allocInst()
|
|
inst.op = OpJmp
|
|
c.insts = append(c.insts, inst)
|
|
return c.top() - 1
|
|
}
|
|
|
|
func (c *compiler) setSplit(i, pc1, pc2 uint) {
|
|
split := c.insts[i]
|
|
split.splitA = pc1
|
|
split.splitB = pc2
|
|
}
|
|
|
|
func (c *compiler) setJump(i, pc uint) {
|
|
jmp := c.insts[i]
|
|
jmp.to = pc
|
|
}
|
|
|
|
func (c *compiler) top() uint {
|
|
return uint(len(c.insts))
|
|
}
|
|
|
|
func (c *compiler) allocInst() *inst {
|
|
if len(c.instsPool) <= 0 {
|
|
c.instsPool = make([]inst, 16)
|
|
}
|
|
inst := &c.instsPool[0]
|
|
c.instsPool = c.instsPool[1:]
|
|
return inst
|
|
}
|