notti/nocgo

dlopen in go without cgo

nocgo's Issues

/usr/lib/x86_64-linux-gnu/libpthread.so: invalid ELF header

Hello @notti ,

I'm trying to test this against my SQLite3 bindings, which I've modified to add Linux support with this library and pushed to a temporary repository: https://github.com/iamacarpet/go-sqlite3-dynamic

Trying to run it, I created a new folder with main_test.go, running with CGO_ENABLED=0 go test

package sqlite3

import (
	"os"
	"testing"

	"database/sql"

	_ "github.com/iamacarpet/go-sqlite3-dynamic"

	"github.com/stretchr/testify/assert"
)

func TestXxx(t *testing.T) {
	path := "test.db"

	f, err := os.Create(path)
	if err != nil {
		t.Fatal(err)
	}
	f.Close()

	db, err := sql.Open(`sqlite3`, path)
	if err != nil {
		t.Fatal(err)
	}

	r, err := db.Exec(`CREATE TABLE test (
		id integer PRIMARY KEY NOT NULL,
		name varchar(30)
	)`)
	if err != nil {
		t.Fatal(err)
	}

	_ = r

	r, err = db.Exec(`INSERT INTO test(name) VALUES ('first') `)
	if err != nil {
		t.Fatal(err)
	}
	rowid, err := r.LastInsertId()
	if err != nil {
		t.Fatal(err)
	}
	affected, err := r.RowsAffected()
	if err != nil {
		t.Fatal(err)
	}
	assert.Equal(t, int64(1), rowid)
	assert.Equal(t, int64(1), affected)

	r, err = db.Exec(`INSERT INTO test(name) VALUES ('second') `)
	if err != nil {
		t.Fatal(err)
	}
	rowid, err = r.LastInsertId()
	if err != nil {
		t.Fatal(err)
	}
	affected, err = r.RowsAffected()
	if err != nil {
		t.Fatal(err)
	}
	assert.Equal(t, int64(2), rowid)
	assert.Equal(t, int64(1), affected)

	db.Close()
	os.Remove(`./test.db`)
}

It's throwing the error:

/tmp/go-build846919307/b001/sqlite3-test.test: error while loading shared libraries: /usr/lib/x86_64-linux-gnu/libpthread.so: invalid ELF header
exit status 127
FAIL    sqlite3-test    0.001s

On Ubuntu 18.04, /usr/lib/x86_64-linux-gnu/libpthread.so is an text file:

$ file /usr/lib/x86_64-linux-gnu/libpthread.so
/usr/lib/x86_64-linux-gnu/libpthread.so: ASCII text
$ cat /usr/lib/x86_64-linux-gnu/libpthread.so
/* GNU ld script
   Use the shared library, but some functions are only in
   the static library, so try that secondarily.  */
OUTPUT_FORMAT(elf64-x86-64)
GROUP ( /lib/x86_64-linux-gnu/libpthread.so.0 /usr/lib/x86_64-linux-gnu/libpthread_nonshared.a )

I checked for references to libpthread.so in your code and found a few.

Looking here , changing libpthread.so to libpthread.so.0 did nothing.

When I changed all occurrences in this file, the error changes to a segfault.

$ CGO_ENABLED=0 go test
fatal error: unexpected signal during runtime execution
[signal SIGSEGV: segmentation violation code=0x2 addr=0x7efe3f722fa8 pc=0x7efe3f50be19]

runtime stack:
runtime.throw(0x746fc8, 0x2a)
        /usr/local/go/src/runtime/panic.go:617 +0x72
runtime.sigpanic()
        /usr/local/go/src/runtime/signal_unix.go:374 +0x4a9

goroutine 1 [syscall, locked to thread]:
runtime.cgocall(0x522090, 0xc0000a7d88, 0xc0000a7da8)
        /usr/local/go/src/runtime/cgocall.go:128 +0x5b fp=0xc0000a7d78 sp=0xc0000a7d40 pc=0x40418b
github.com/notti/nocgo.callWrapper(0xc000084060, 0x2a, 0x30, 0xc000000002, 0x29, 0x30, 0x7efe3f6d46d0, 0x0, 0x40b4ed, 0xc0000a7f28, ...)
        ~/go-projects/src/github.com/notti/nocgo/call_amd64.s:69 +0x49 fp=0xc0000a7da8 sp=0xc0000a7d78 pc=0x522069
github.com/notti/nocgo.Open(0x746546, 0x29, 0x40c248, 0x70, 0x71bdc0)
        ~/go-projects/src/github.com/notti/nocgo/dlopen.go:61 +0x84 fp=0xc0000a7e00 sp=0xc0000a7da8 pc=0x521114
github.com/iamacarpet/go-sqlite3-dynamic.registerLibrary()
        ~/go-projects/src/github.com/iamacarpet/go-sqlite3-dynamic/dynamic_register_linux.go:65 +0x4b fp=0xc0000a7f38 sp=0xc0000a7e00 pc=0x527bcb
github.com/iamacarpet/go-sqlite3-dynamic.init.0()
        ~/go-projects/src/github.com/iamacarpet/go-sqlite3-dynamic/sqlite3.go:23 +0x22 fp=0xc0000a7f68 sp=0xc0000a7f38 pc=0x5290e2
github.com/iamacarpet/go-sqlite3-dynamic.init()
        <autogenerated>:1 +0x93 fp=0xc0000a7f78 sp=0xc0000a7f68 pc=0x52e863
sqlite3-test.init()
        <autogenerated>:1 +0x54 fp=0xc0000a7f88 sp=0xc0000a7f78 pc=0x695954
main.init()
        <autogenerated>:1 +0x54 fp=0xc0000a7f98 sp=0xc0000a7f88 pc=0x695bf4
runtime.main()
        /usr/local/go/src/runtime/proc.go:188 +0x1c8 fp=0xc0000a7fe0 sp=0xc0000a7f98 pc=0x42ea08
runtime.goexit()
        /usr/local/go/src/runtime/asm_amd64.s:1337 +0x1 fp=0xc0000a7fe8 sp=0xc0000a7fe0 pc=0x45b481
exit status 2
FAIL    sqlite3-test    0.009s

My Go version:

$ go version
go version go1.12.4 linux/amd64

Am I doing something stupid?

Regards,
iamacarpet

Go byte should be C unsigned char

I see that in the README it lists Go's byte and int8 as a C char. However, the Go spec says,

byte alias for uint8

Since uint8 is from [0,255] as is an unsigned char in C I believe that Go's byte should be a C unsigned char.

cgocall unavailable without CGO_ENABLED=0

Hello @notti

Just finishing up my documentation and I noticed in yours it says:

WARNING nocgo supports both cgo and missing cgo as environment. So if you want to ensure cgo not being used don't forget CGO_ENABLED=0 as environment variable to go build.

However, building without CGO_ENABLED=0 always throws me this error:

fatal error: cgocall unavailable

goroutine 1 [running, locked to thread]:
runtime.throw(0x4f53b4, 0x13)
        /usr/local/go/src/runtime/panic.go:617 +0x72 fp=0xc000090d50 sp=0xc000090d20 pc=0x429d02
runtime.cgocall(0x4a8ed0, 0xc000090d98, 0xc000090db8)
        /usr/local/go/src/runtime/cgocall.go:96 +0xe4 fp=0xc000090d88 sp=0xc000090d50 pc=0x403d34
github.com/notti/nocgo.callWrapper(0xc000086010, 0x10, 0x10, 0xc000000002, 0xf, 0x10, 0x7fbff35f9d98, 0x0, 0xaa, 0xc000090f38, ...)
        ~/go-projects/src/github.com/notti/nocgo/call_amd64.s:69 +0x49 fp=0xc000090db8 sp=0xc000090d88 pc=0x4a8ea9
github.com/notti/nocgo.Open(0x4f47d3, 0xf, 0x40b768, 0x70, 0x4e6f60)
        ~/go-projects/src/github.com/notti/nocgo/dlopen.go:61 +0x84 fp=0xc000090e10 sp=0xc000090db8 pc=0x4a7f54
github.com/iamacarpet/go-sqlite3-dynamic.registerLibrary()
        ~/go-projects/src/github.com/iamacarpet/go-sqlite3-dynamic/dynamic_register_linux.go:65 +0x4b fp=0xc000090f48 sp=0xc000090e10 pc=0x4ac4cb
github.com/iamacarpet/go-sqlite3-dynamic.init.0()
        ~/go-projects/src/github.com/iamacarpet/go-sqlite3-dynamic/sqlite3.go:23 +0x22 fp=0xc000090f78 sp=0xc000090f48 pc=0x4ad9e2
github.com/iamacarpet/go-sqlite3-dynamic.init()
        <autogenerated>:1 +0x93 fp=0xc000090f88 sp=0xc000090f78 pc=0x4b3a33
main.init()
        <autogenerated>:1 +0x54 fp=0xc000090f98 sp=0xc000090f88 pc=0x4b4654
runtime.main()
        /usr/local/go/src/runtime/proc.go:188 +0x1c8 fp=0xc000090fe0 sp=0xc000090f98 pc=0x42b628
runtime.goexit()
        /usr/local/go/src/runtime/asm_amd64.s:1337 +0x1 fp=0xc000090fe8 sp=0xc000090fe0 pc=0x454c71

Is this expected behavior?

Regards,
iamacarpet

LICENSE file?

Hey, this is an incredible piece of work, but I would feel much better about using it with a license file.

Any chance of adding a license?

If you are looking for suggestions, I would say consider MIT License.

Thanks for this great way of calling .so files without cgo.

Cameron