README.md

This is example of reproducing a panic on reading UAST from client.ParseUAST(), while iterating over files in Git repo using go-git.

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x8 pc=0x1186147]

goroutine 1 [running]:
github.com/bblfsh/sdk/uast.(*Node).ProtoSize(0x0, 0xc4201ddda0)

Steps to reproduce:

git clone https://github.com/damoeb/kalipo.git
go run pyFromGit2ast2pb.go

You can change "java" to "python" (L42 and L60) back and forth you can get more interesting results.

I.e

• bblfsh/python-driver#26
• bblfsh/java-driver#23

pyFromGit2ast2pb.go

package main

import (
	"context"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/bblfsh/sdk/protocol"

	"gopkg.in/src-d/go-git.v4"
	"gopkg.in/src-d/go-git.v4/plumbing/object"

	"google.golang.org/grpc"
)

// Note: start the server with:
// docker run --privileged -p 9432:9432 --name bblfsh bblfsh/server

func main() {
	if len(os.Args) < 2 {
		fmt.Printf("Use %s <path-to-clone>\n", os.Args[0])
		os.Exit(1)
	}
	// Connect to the running server
	conn, err := grpc.Dial("0.0.0.0:9432", grpc.WithTimeout(time.Second*2), grpc.WithInsecure())
	checkIfError(err)
	client := protocol.NewProtocolServiceClient(conn)

	r, err := git.PlainOpen(os.Args[1])
	checkIfError(err)
	ref, err := r.Head()
	checkIfError(err)
	commit, err := r.CommitObject(ref.Hash())
	checkIfError(err)
	tree, err := commit.Tree()
	checkIfError(err)

	err = tree.Files().ForEach(func(f *object.File) error {
		if !strings.HasSuffix(f.Name, ".py") {
			return nil
		}

		contentstr, err := f.Contents()
		if err != nil {
			fmt.Printf("\t\tReading file:%s failed, reason: %s\n", f.Name, err)
			return err
		}

		fmt.Printf("100644 blob %s    %s\n", f.Hash, f.Name)
		fmt.Printf("\tParsing file:%s, size:%d\n", f.Name, len(contentstr))
		if err != nil {
			fmt.Printf("\t\tGeting content for %s failed, reason: %s\n", f.Name, err)
			return err
		}

		req := &protocol.ParseUASTRequest{Filename: f.Name,
			Content:  contentstr,
			Language: "python"}

		resp, err := client.ParseUAST(context.TODO(), req)
		if err != nil {
			fmt.Printf("\t\tError - ParseUAST failed, reposne is nil, error:%v for %s\n", err, f.Name)
			return err
		} else if resp == nil {
			fmt.Printf("\t\tNo error, but - ParseUAST failed, response is nil\n")
			return err
		} else if (len(resp.Errors) != 0) || (resp.Status != protocol.Ok) {
			fmt.Printf("\t\tNo error, but - ParseUAST status:%s, error:%v for %s\n", resp.Status, resp.Errors, f.Name)
			return err
		}

		// FIXME: Crashes sometimes here, check resp.UAST? :(
		data, err := resp.UAST.Marshal()
		if err != nil {
			fmt.Println("]\t\tError: failed to save UAST to .pb for file: ", f.Name)
			return err
		}

		outFile := "out/" + filepath.Base(f.Name) + ".pb"
		err = ioutil.WriteFile(outFile, data, 00644)
		checkIfError(err)
		fmt.Printf("\tUAST for %s, saved to %s\n", f.Name, outFile)
		return nil
	})
}
func checkIfError(err error) {
	if err == nil {
		return
	}

	fmt.Printf("\x1b[31;1m%s\x1b[0m\n", fmt.Sprintf("error: %s", err))
	os.Exit(1)
}

Could you try again with the new ~master of the Python driver? Anyway it seems there is an issue with the SDK not checking nil pointers somewhere.

Thank you! Will follow your instructions to get everything latest locally bblfsh/bblfshd#34 (comment) and report issues on relevant repositories (server/python)!