Static version of tdjson? about td

[Arman92]

I have a full tdlib-tdjson binding package here (Autogenerated all types/methods from tdlib.tl) : https://github.com/Arman92/go-tdlib

[levlam]

We haven't tested static linking of the libtdjson_static library to Golang code, but it looks like Golang (using cgo) supports static linking of С libraries and everything should work fine. You will also need to statically link all TDLib dependencies, namely ilibtdactor, libtddb, libtdnet, libtdsqlite, libtdutils, libcrypto, libssl, libz and standard C++ library (libc++/libstdc++). What errors do you get?

[savely-krasovsky]

@levlam seems like the libs order is the key. After researching CMakeLists.txt I recover the right order:

/*
#cgo LDFLAGS: -ltdjson_static -ltdjson_private -ltdclient -ltdcore -ltdactor -ltddb -ltdsqlite -ltdnet -ltdutils -lstdc++ -lssl -lcrypto -ldl -lz -lm
#include <stdlib.h>
#include <td/telegram/td_json_client.h>
#include <td/telegram/td_log.h>
*/
import "C"

After this I compiled the binary, but with few warnings:

//usr/local/lib/libtdsqlite.a(sqlite3.c.o): In function `unixDlOpen':
sqlite3.c:(.text+0x15b17): warning: Using 'dlopen' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
//usr/local/lib/libtdutils.a(IPAddress.cpp.o): In function `td::IPAddress::init_host_port(td::CSlice, td::CSlice)':
IPAddress.cpp:(.text._ZN2td9IPAddress14init_host_portENS_6CSliceES1_+0x244): warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking

Because of it seems like Go static builds linked with glibc are not working:

fatal error: unexpected signal during runtime execution
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x0]

runtime stack:
runtime.throw(0x1b4c034, 0x2a)
        /usr/lib/go-1.9/src/runtime/panic.go:605 +0x95
runtime.sigpanic()
        /usr/lib/go-1.9/src/runtime/signal_unix.go:351 +0x2b8

goroutine 1 [syscall, locked to thread]:
runtime.cgocall(0x4cb380, 0xc42005bde0, 0xc42005be01)
        /usr/lib/go-1.9/src/runtime/cgocall.go:132 +0xe4 fp=0xc42005bdb0 sp=0xc42005bd70 pc=0x4027b4
github.com/L11R/go-tdjson._Cfunc_td_json_client_create(0x0)
        github.com/L11R/go-tdjson/_obj/_cgo_gotypes.go:92 +0x4a fp=0xc42005bde0 sp=0xc42005bdb0 pc=0x4c7cea
github.com/L11R/go-tdjson.NewClient(0x1b45955)
        /home/savely/go/src/github.com/L11R/go-tdjson/tdjson.go:37 +0x40 fp=0xc42005be48 sp=0xc42005bde0 pc=0x4c8050
main.main()
        /home/savely/go/src/Aggregator/main.go:29 +0xb6 fp=0xc42005bf80 sp=0xc42005be48 pc=0x4cab66
runtime.main()
        /usr/lib/go-1.9/src/runtime/proc.go:195 +0x226 fp=0xc42005bfe0 sp=0xc42005bf80 pc=0x42afb6
runtime.goexit()
        /usr/lib/go-1.9/src/runtime/asm_amd64.s:2337 +0x1 fp=0xc42005bfe8 sp=0xc42005bfe0 pc=0x456cd1

goroutine 5 [syscall]:
os/signal.signal_recv(0x0)
        /usr/lib/go-1.9/src/runtime/sigqueue.go:131 +0xa6
os/signal.loop()
        /usr/lib/go-1.9/src/os/signal/signal_unix.go:22 +0x22
created by os/signal.init.0
        /usr/lib/go-1.9/src/os/signal/signal_unix.go:28 +0x41

Article with very similar problem:
https://tschottdorf.github.io/golang-static-linking-bug

To finalize:
go build -a -ldflags '-linkmode external -extldflags -static' -- not working, so we can't build TOTALLY static build.
go build -- working. We can launch it on the machines without TDlib, but have to install libs like libz, etc. It is quite acceptable.

[levlam]

I have a few suggestions for you:

1. You can try to manually remove calls to some glibc functions that can't be linked statically.
   In order to remove call to dlopen in sqlite, just add to sqlite/CMakeFiles.txt
   target_compile_definitions(tdsqlite PRIVATE -DSQLITE_OMIT_LOAD_EXTENSION)
   In order to remove call to getaddrinfo, replace function in tdutils/td/utils/port/IPAddress.cpp with
   Status IPAddress::init_host_port(CSlice host, CSlice port) {
   return Status::Error("Unsupported");
   }
   There is no critical functionality in TDLib which depends on that function, it should work fine.
2. As noted in the linked by you article, you can try to use another libc, for example, musl.

[savely-krasovsky]

@levlam thanks for suggestions!

1. I tried first one, two warnings were disappear, but appeared another one 😢

/usr/lib/x86_64-linux-gnu/libcrypto.a(dso_dlfcn.o): In function `dlfcn_globallookup':
(.text+0x11): warning: Using 'dlopen' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking

2. If I understood correctly, I should compile TDLib with musl, but I got many errors, like:
   /home/savely/td/sqlite/sqlite/sqlite3.c:20258:26: fatal error: openssl/rand.h: No such file
   I tried to add -I/usr/include at sqlite/CMakeLists.txt, but then got another errors, tried to solve them, but they appearing "avalanche-like".

[levlam]

1. This comes from OpenSSL now. You could try to build OpenSSL from sources with no-dso configure option, which should remove calls to dlopen.
2. You probably also need to recompile OpenSSL and zlib with musl and specify musl-compiled libraries as dependencies when building TDLib, It doesn't sounds like an easy way.

[savely-krasovsky]

@levlam thanks for advices. For me easier to link statically against TDLib only. Other libs like OpenSSL, ZLib and others is simpler to install on target system from package manager.

For readers:
Set right flags for CGO:

/*
#cgo LDFLAGS: -ltdjson_static -ltdjson_private -ltdclient -ltdcore -ltdactor -ltddb -ltdsqlite -ltdnet -ltdutils -lstdc++ -lssl -lcrypto -ldl -lz -lm
#include <stdlib.h>
#include <td/telegram/td_json_client.h>
#include <td/telegram/td_log.h>
*/
import "C"

Compile dynamic binary with default command:

go build

Now your binary will depends only from libs like OpenSSL and zLib.