gollvm: Using External Go Packages with gollvm

[codersguild]

What version of Go are you using (go version)?

$ go version
go version go1.13.8 linux/amd64

Does this issue reproduce with the latest release?

Yes. I am not able to use/import the external go packages with gccgo or llvm-goc. I want to generate LLVM IR for a go program that uses an external package. It errors out saying package not found.

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/virtualvms/.cache/go-build"
GOENV="/home/virtualvms/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/var/hyperledger/gochaincode/gopath"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/lib/go-1.13"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/lib/go-1.13/pkg/tool/linux_amd64"
GCCGO="/usr/bin/gccgo"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build376284318=/tmp/go-build -gno-record-gcc-switches"

What did you do?

I want to generate LLVM IR for a go program that uses an external package say a package/module like github.com/hyperledger/fabric-chaincode-go. I am using GO11MODULE to download and vendor the packages. It still fails saying the modules are not found. All required files are in the same folder.

payment_main.go:10:52: error: import file 'github.com/hyperledger/fabric-chaincode-go/pkg/cid' not found
payment_main.go:11:49: error: import file 'github.com/hyperledger/fabric-chaincode-go/shim' not found
payment_main.go:12:2: error: import file 'github.com/hyperledger/fabric-protos-go/peer' not found

What did you expect to see?

Proper build and LLVM IR of my go program

What did you see instead?

Error, External package not found during build process of gccgo or llvm-goc.

[Keithcat1]

I don't think it's a problem with the GC Go toolchain. You'd probably be better off posting an issue on the Gollvm bug tracker instead.

[codersguild]

The bug/issue tracker link at https://go.googlesource.com/gollvm/#wheretofile brings me golang/go issues.
https://github.com/golang/go/issues where I wrote my issue by mentioning gollvm as asked.

[ianlancetaylor]

Yes, this is the right issue tracker.

But there isn't enough information here. Please tell us precisely what you did and show us precisely what happened. Thanks.

[codersguild]

I used external packages in my go program as shown below.

package main 

import (
    "crypto/x509"
    "encoding/json"
    "fmt"
    "strconv"
    "strings"
    "time"
    "github.com/hyperledger/fabric-chaincode-go/pkg/cid"
    "github.com/hyperledger/fabric-chaincode-go/shim"
    peer "github.com/hyperledger/fabric-protos-go/peer"
)

... 

The last three are external packages from github.com/hyperledger. Now I passed it to llvm-goc. I build gollvm with ninja as it is mentioned in gollvm

It gives the following errors.

payment_main.go:10:52: error: import file 'github.com/hyperledger/fabric-chaincode-go/pkg/cid' not found
payment_main.go:11:49: error: import file 'github.com/hyperledger/fabric-chaincode-go/shim' not found
payment_main.go:12:2: error: import file 'github.com/hyperledger/fabric-protos-go/peer' not found

I am vendoring the packages in a folder vendor using GO11MODULE=on and then specifying the required files in go.mod.

How do I make llvm-goc use these external go modules when emitting IR

$ llvm-goc -S -emit-llvm -O3 payment_main.go
payment_main.go:10:52: error: import file 'github.com/hyperledger/fabric-chaincode-go/pkg/cid' not found
payment_main.go:11:49: error: import file 'github.com/hyperledger/fabric-chaincode-go/shim' not found
payment_main.go:12:2: error: import file 'github.com/hyperledger/fabric-protos-go/peer' not found

[ianlancetaylor]

Don't build using llvm-goc directly. Use the Go tool, and run go build.

[codersguild]

I tried using go build by following the steps to use go work output. It still gives the same error.

I am trying to do something like this

% go build -work -x mypackage.go 1> transcript.txt 2>&1
% egrep '(WORK=|llvm-goc -c)' transcript.txt
WORK=/tmp/go-build887931787
/t/bin/llvm-goc -c -g -m64 -fdebug-prefix-map=$WORK=/tmp/go-build \
  -gno-record-gcc-switches -fgo-pkgpath=command-line-arguments \
  -fgo-relative-import-path=/mygopath/src/tmp -o $WORK/b001/_go_.o \
  -I $WORK/b001/_importcfgroot_ ./mypackage.go
% /t/bin/llvm-goc -c -g -m64 -fdebug-prefix-map=$WORK=/tmp/go-build \
  -gno-record-gcc-switches -fgo-pkgpath=command-line-arguments \
  -fgo-relative-import-path=/mygopath/src/tmp \
  -I $WORK/b001/_importcfgroot_ -o mypackage.ll -S -emit-llvm \
  ./mypackage.go
% ls -l mypackage.ll
...
%

[ianlancetaylor]

If you are using module mode (if the package you are trying to build has a go.mod file), go build should download the imports you need. If not you'll need to fetch them using go get. But this use of the go tool doesn't have anything to do with GoLLVM.

[codersguild]

Lets me elaborate on a scenario I am trying to fix at my end. I need llvm-goc to generate LLVM IR for a toy go program as below.

package main

/*
#include <stdio.h>
#define MAX 150000
*/
import "C"
import "fmt"

func main() {
    fmt.Println(C.MAX)
    fmt.Println("Hello")
}

As you can see, I have imported "C" here. It is just exemplary here.

I am building it with go. which generates a binary.

$ go build main.go
$ go run main.go 
150000
Hello

So go is able to detect the import. Now I want to create an LLVM IR for this program. I have build ninja gollvm and using llvm-goc to generate an IR.

$ llvm-goc -S -emit-llvm main.go -o main.ll

The error I am getting is :

$ main.go:7:9: error: import file 'C' not found
$ main.go:11:14: error: reference to undefined name 'C'

I need a way to fix this. I am getting the same error when I am doing it this way.

$ go build -work -x main.go 1> transcript.txt 2>&1

$ egrep '(WORK=|llvm-goc -c)' transcript.txt
WORK=/tmp/go-build887931787
/t/bin/llvm-goc -c -g -m64 -fdebug-prefix-map=$WORK=/tmp/go-build \
  -gno-record-gcc-switches -fgo-pkgpath=command-line-arguments \
  -fgo-relative-import-path=/mygopath/src/tmp -o $WORK/b001/_go_.o \
  -I $WORK/b001/_importcfgroot_ ./main.go

$ main.go:7:9: error: import file 'C' not found
$ main.go:11:14: error: reference to undefined name 'C'

[erifan]

Hi, I tried your test case, but I can't reproduce it. This is the version information I used to build gollvm:

llvm: ede6005e7092ddae454e4d365d8adefeaec1f5e3
gollvm: 0edc44a02852dd0d56cac35163a45634b497d6cd
gofrontend: ea58b8491064fbed18a220571a3043c38dccf7c7

Can you tell us what version you used?

[codersguild]

I will share it asap.

[ianlancetaylor]

I don't understand why you are pulling commands out of the go build -x output and running them separately. Does go build succeed? If so, use that. Don't try to pull commands out of it and expect them to work without also running all the other commands.

[codersguild]

The go build succeeds. It produces a correct transcript. But when I execute this step

$ egrep '(WORK=|llvm-goc -c)' transcript.txt
WORK=/tmp/go-build887931787
/t/bin/llvm-goc -c -g -m64 -fdebug-prefix-map=$WORK=/tmp/go-build \
  -gno-record-gcc-switches -fgo-pkgpath=command-line-arguments \
  -fgo-relative-import-path=/mygopath/src/tmp -o $WORK/b001/_go_.o \
  -I $WORK/b001/_importcfgroot_ ./main.go

It gives me an error saying.

$ main.go:7:9: error: import file 'C' not found
$ main.go:11:14: error: reference to undefined name 'C'

I may be wrong in the way I am trying to generate the IR. I am following the steps here.

https://go.googlesource.com/gollvm/#seetheir

My exact steps.

Go Build Work :

$ go build -work -x main.go 1> transcript_main.txt 2>&1

llvm-goc exec from go work steps : This fails.

$ export $(egrep '(WORK=|llvm-goc -c)' transcript_main.txt)
$ llvmgoc -c -O2 -g -m64 -fdebug-prefix-map=$WORK=/tmp/go-build \ 
-gno-record-gcc-switches -fgo-relative-import-path=$GOPATH \ 
-o $WORK/b001/_go_.o -I $WORK/b001/_importcfgroot_ ./main.go 

GOAPTH is configured to use the gollvm libgo library packages.

[cherrymui]

Can you paste the exact commands you run, without filtering? (It could be lengthy, and that is fine.)

If you run the commands from go build -x manually, you need to run all the commands, not only the ones with llvm-goc.

[codersguild]

I didn't use any other command . I shall share a full dump of what transcript.txt contains.

[shawtao]

Hey, have you solve the problem yet? I met the same problem and i don't know how to do with it too.

[cherrymui]

No. It is still unclear what the problem is. It could be helpful if any of you share the exact command for how to reproduce this.

[shawtao]

I thing i have figure out the problem. I tried to use gollvm to compile runc to IR, I use this go build command: $ $(GO_BUILD) -gccgoflags -### -x -work -o runc . use -gccgoflags to pass -### to llvm-goc so llvm-goc just print the command it use to compile the project like that

WORK=/tmp/go-build179018028 go build: when using gccgo toolchain, please pass linker flags using -gccgoflags, not -ldflags mkdir -p $WORK/b001/ cat >$WORK/b001/_gomod_.go << 'EOF' # internal package main import _ "unsafe" //go:linkname __set_debug_modinfo__ runtime.setmodinfo func __set_debug_modinfo__(string) func init() { __set_debug_modinfo__("0w\xaf\f\x92t\b\x02A\xe1\xc1\a\xe6\xd6\x18\xe6path\tgithub.com/opencontainers/runc\nmod\tgithub.com/opencontainers/runc\t(devel)\t\ndep\tgithub.com/checkpoint-restore/go-criu/v4\tv4.1.0\t\ndep\tgithub.com/cilium/ebpf\tv0.0.0-20200702112145-1c8d4c9ef775\t\ndep\tgithub.com/containerd/console\tv1.0.0\t\ndep\tgithub.com/coreos/go-systemd/v22\tv22.1.0\t\ndep\tgithub.com/cpuguy83/go-md2man/v2\tv2.0.0-20190314233015-f79a8a8ca69d\t\ndep\tgithub.com/cyphar/filepath-securejoin\tv0.2.2\t\ndep\tgithub.com/docker/go-units\tv0.4.0\t\ndep\tgithub.com/godbus/dbus/v5\tv5.0.3\t\ndep\tgithub.com/golang/protobuf\tv1.4.2\t\ndep\tgithub.com/moby/sys/mountinfo\tv0.1.3\t\ndep\tgithub.com/mrunalp/fileutils\tv0.0.0-20200520151820-abd8a0e76976\t\ndep\tgithub.com/opencontainers/runtime-spec\tv1.0.3-0.20200728170252-4d89ac9fbff6\t\ndep\tgithub.com/opencontainers/selinux\tv1.6.0\t\ndep\tgithub.com/pkg/errors\tv0.9.1\t\ndep\tgithub.com/russross/blackfriday/v2\tv2.0.1\t\ndep\tgithub.com/seccomp/libseccomp-golang\tv0.9.1\t\ndep\tgithub.com/shurcooL/sanitized_anchor_name\tv1.0.0\t\ndep\tgithub.com/sirupsen/logrus\tv1.6.0\t\ndep\tgithub.com/syndtr/gocapability\tv0.0.0-20200815063812-42c35b437635\t\ndep\tgithub.com/urfave/cli\tv1.22.1\t\ndep\tgithub.com/vishvananda/netlink\tv1.1.0\t\ndep\tgithub.com/vishvananda/netns\tv0.0.0-20191106174202-0a2b9b5464df\t\ndep\tgithub.com/willf/bitset\tv1.1.11-0.20200630133818-d5bec3311243\t\ndep\tgolang.org/x/sys\tv0.0.0-20200728102440-3e129f6d46b1\t\ndep\tgoogle.golang.org/protobuf\tv1.23.0\t\n\xf92C1\x86\x18 r\x00\x82B\x10A\x16\xd8\xf2") } EOF and i found a key command that llvm-goc use to generate go.o: llvm-goc -c -O2 -g -m64 -fdebug-prefix-map=$WORK=/tmp/go-build -gno-record-gcc-switches -o $WORK/b001/_go_.o -fPIE -I $WORK/b001/_importcfgroot_ -### ./checkpoint.go ./create.go ./delete.go ./events.go ./exec.go ./init.go ./kill.go ./list.go ./main.go ./notify_socket.go ./pause.go ./ps.go ./restore.go ./rlimit_linux.go ./rootless_linux.go ./run.go ./signals.go ./spec.go ./start.go ./state.go ./tty.go ./update.go ./utils.go ./utils_linux.go $WORK/b001/_gomod_.go so i modify this command: add -S -emit-llvm and change go.o to go.ll and finally successfully generate it.

[shawtao]

In short,You can use go build -gccgoflags -### -x -work to compile your project and it will show the command that llvm-goc used. Looking for the command llvm-goc used to generate the .o file and modify it to generate .ll file.

[codersguild]

Cool ! I have to try it out then. Thanks for your analysis.

[thanm]

Closing this issue out, I don't see anything actionable here.