1 files changed, 96 insertions, 0 deletions
diff --git a/vendor/github.com/mattermost/rsc/regexp/regmerge/main.go b/vendor/github.com/mattermost/rsc/regexp/regmerge/main.go
new file mode 100644
index 000000000..672337a04
--- /dev/null
+++ b/vendor/github.com/mattermost/rsc/regexp/regmerge/main.go
@@ -0,0 +1,96 @@
+// Copyright 2012 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 (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"regexp/syntax"
+	"runtime/pprof"
+)
+
+var maxState = flag.Int("m", 1e5, "maximum number of states to explore")
+var cpuprof = flag.String("cpuprofile", "", "cpu profile file")
+
+func main() {
+	flag.Usage = func() {
+		fmt.Fprintf(os.Stderr, "usage: regmerge [-m maxstate] regexp [regexp2 regexp3....]\n")
+		os.Exit(2)
+	}
+	flag.Parse()
+
+	if len(flag.Args()) < 1 {
+		flag.Usage()
+	}
+	
+	os.Exit(run(flag.Args()))
+}
+
+func run(args []string) int {
+	if *cpuprof != "" {
+		f, err := os.Create(*cpuprof)
+		if err != nil {
+			log.Fatal(err)
+		}
+		pprof.StartCPUProfile(f)
+		defer pprof.StopCPUProfile()
+	}
+	
+	m, err := compile(flag.Args()...)
+	if err != nil {
+		log.Fatal(err)
+	}
+	n := 100
+	for ;; n *= 2 {
+		if n >= *maxState {
+			if n >= 2* *maxState {
+				fmt.Printf("reached state limit\n")
+				return 1
+			}
+			n = *maxState
+		}
+		log.Printf("try %d states...\n", n)
+		s, err := m.findMatch(n)
+		if err == nil {
+			fmt.Printf("%q\n", s)
+			return 0
+		}
+		if err != ErrMemory {
+			fmt.Printf("failed: %s\n", err)
+			return 3
+		}
+	}
+	panic("unreachable")
+}
+
+func compile(exprs ...string) (*matcher, error) {
+	var progs []*syntax.Prog
+	for _, expr := range exprs {
+		re, err := syntax.Parse(expr, syntax.Perl)
+		if err != nil {
+			return nil, err
+		}
+		sre := re.Simplify()
+		prog, err := syntax.Compile(sre)
+		if err != nil {
+			return nil, err
+		}
+		if err := toByteProg(prog); err != nil {
+			return nil, err
+		}
+		progs = append(progs, prog)
+	}
+	m := &matcher{}
+	if err := m.init(joinProgs(progs), len(progs)); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+func bug() {
+	panic("regmerge: internal error")
+}