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// Copyright 2011 Google Inc. All Rights Reserved.
// This file is available under the Apache license.
//go:build gofuzz
package runtime
import (
"bufio"
"bytes"
"context"
"flag"
"fmt"
"github.com/jaqx0r/mtail/internal/logline"
"github.com/jaqx0r/mtail/internal/runtime/compiler"
"github.com/jaqx0r/mtail/internal/runtime/vm"
)
// U+2424 SYMBOL FOR NEWLINE
const SEP = ""
// Enable this when debugging with a fuzz crash artifact; it slows the fuzzer down when enabled.
const dumpDebug = false
func Fuzz(data []byte) int {
// Data contains the program and sample input, separated by SEP.
offset := bytes.Index(data, []byte(SEP))
if offset < 0 {
// If no SEP, then append one and an empty line of input.
offset = len(data)
data = append(data, []byte(SEP+"\n")...)
}
fmt.Printf("data len %d, offset is %d, input starts at %d\n", len(data), offset, offset+len(SEP))
cOpts := []compiler.Option{}
if dumpDebug {
cOpts = append(cOpts, compiler.EmitAst(), compiler.EmitAstTypes())
}
c, err := compiler.New(cOpts...)
if err != nil {
fmt.Println(err)
return 0
}
obj, err := c.Compile("fuzz", bytes.NewReader(data[:offset]))
if err != nil {
fmt.Println(err)
return 0 // false
}
v := vm.New("fuzz", obj, false, nil, dumpDebug, dumpDebug)
if dumpDebug {
fmt.Println(v.DumpByteCode())
}
v.HardCrash = true
scanner := bufio.NewScanner(bytes.NewBuffer(data[offset+len(SEP):]))
for scanner.Scan() {
v.ProcessLogLine(context.Background(), logline.New(context.Background(), "fuzz", scanner.Text()))
}
return 1
}
func init() {
// We need to successfully parse flags to initialize the glog logger used
// by the compiler, but the fuzzer gets called with flags captured by the
// libfuzzer main, which we don't want to intercept here.
flag.CommandLine.Parse([]string{})
}
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