Golang cmd/go: trimpath does not clean some CGO C filepaths

Go version

go version go1.21.6 linux/amd64

Output of go env in your module/workspace:

GO111MODULE=''
GOARCH='amd64'
GOBIN=''
GOCACHE='/root/.cache/go-build'
GOENV='/root/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/root/go/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/root/go'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.21.6'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/dev/null'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build1815251191=/tmp/go-build -gno-record-gcc-switches'

What did you do?

Compiled a go package containing C code dependencies using -trimpath flag.

go version -m geth

go-ethereum/build/bin/geth: go1.21.6
        ...
    build   -buildmode=exe
    build   -compiler=gc
    build   -tags=urfave_cli_no_docs,ckzg
    build   -trimpath=true
    build   DefaultGODEBUG=panicnil=1
    build   CGO_ENABLED=1
    build   GOARCH=amd64
    build   GOOS=linux
    build   GOAMD64=v1
    build   vcs=git
    build   vcs.revision=2bd6bd01d2e8561dd7fc21b631f4a34ac16627a1
    build   vcs.time=2024-02-27T11:51:11Z
    build   vcs.modified=false

What did you see happen?

Some C packages with full paths embedded in binaries.

/root/go/pkg/mod/github.com/karalabe/usb@v0.0.2/libusb/libusb/os/linux_netlink.c
/root/go/pkg/mod/github.com/karalabe/usb@v0.0.2/libusb/libusb/os/linux_usbfs.c
/root/go/pkg/mod/github.com/ethereum/c-kzg-4844@v0.4.0/bindings/go/../../src/c_kzg_4844.c

What did you expect to see?

Relative, trimmed, paths for all C libraries.

Comment From: Jorropo

I was not able to reproduce doing cd cmd/geth && go build -trimpath . with 0d4c38865e9cda492e71221c4c429d9b1bec8ac5 and 9f9dd2bfd8a09083b21767d13df38ff67d7236d8 can you please post a reproduction ?

Comment From: vivi365

Hi,

Running this docker file should show some path embeddings in the .rodata.

FROM ubuntu:bionic

RUN apt-get update && apt-get install gcc-multilib git ca-certificates wget -yq --no-install-recommends
RUN git clone --branch master https://github.com/ethereum/go-ethereum.git && cd go-ethereum && git fetch
RUN wget https://go.dev/dl/go1.21.6.linux-amd64.tar.gz && \
    rm -rf /usr/local/go && \
    tar -C /usr/local -xzf go1.21.6.linux-amd64.tar.gz && \
    export PATH=$PATH:/usr/local/go/bin

RUN cd go-ethereum && git fetch && git checkout 0d4c38865e9cda492e71221c4c429d9b1bec8ac5 && \
    cd cmd/geth && CGO_ENABLED=1 /usr/local/go/bin/go build -trimpath .

RUN mv /go-ethereum/cmd/geth/geth /geth && readelf -p .rodata geth | grep /root/go/pkg >> full-paths.txt

/# cat full-paths.txt 
  [9e5270]  /root/go/pkg/mod/github.com/karalabe/hid@v1.0.1-0.20240306101548-573246063e52/libusb/libusb/libusbi.h
  [9e52d8]  /root/go/pkg/mod/github.com/karalabe/hid@v1.0.1-0.20240306101548-573246063e52/libusb/libusb/os/events_posix.c
  [9e5348]  /root/go/pkg/mod/github.com/karalabe/hid@v1.0.1-0.20240306101548-573246063e52/libusb/libusb/os/linux_netlink.c
  [9e53b8]  /root/go/pkg/mod/github.com/karalabe/hid@v1.0.1-0.20240306101548-573246063e52/libusb/libusb/os/linux_usbfs.c
  [9e5428]  /root/go/pkg/mod/github.com/karalabe/hid@v1.0.1-0.20240306101548-573246063e52/libusb/libusb/core.c
  [9e54c0]  /root/go/pkg/mod/github.com/karalabe/hid@v1.0.1-0.20240306101548-573246063e52/libusb/libusb/hotplug.c
  [9e5528]  /root/go/pkg/mod/github.com/karalabe/hid@v1.0.1-0.20240306101548-573246063e52/libusb/libusb/io.c

Comment From: Jorropo

It is indeed broken, but not natively on arch (even with go1.21.6), I need to go through your Dockerfile to make it not work. Using go1.22.2 didn't fixed anything. However using today's ubuntu:latest base image fixed it for both go1.22.2 and go1.21.6:

-FROM ubuntu:bionic
+FROM ubuntu

RUN apt-get update && apt-get install gcc-multilib git ca-certificates wget -yq --no-install-recommends
RUN git clone --branch master https://github.com/ethereum/go-ethereum.git && cd go-ethereum && git fetch
-RUN wget https://go.dev/dl/go1.21.6.linux-amd64.tar.gz && \
+RUN wget https://go.dev/dl/go1.22.2.linux-amd64.tar.gz && \
    rm -rf /usr/local/go && \
-   tar -C /usr/local -xzf go1.21.6.linux-amd64.tar.gz && \
+   tar -C /usr/local -xzf go1.22.2.linux-amd64.tar.gz && \
    export PATH=$PATH:/usr/local/go/bin

RUN cd go-ethereum && git fetch && git checkout 0d4c38865e9cda492e71221c4c429d9b1bec8ac5 && \
    cd cmd/geth && CGO_ENABLED=1 /usr/local/go/bin/go build -trimpath .

RUN mv /go-ethereum/cmd/geth/geth /geth && readelf -p .rodata geth | grep /root/go/pkg >> full-paths.txt

~~I guess some integration bug somewhere with older releases of GCC ¿~~ could be a million thing idk That where I'm gonna stop looking into this.

Comment From: Jorropo

cc cmd/cgo @golang/compiler

Comment From: Jorropo

Btw thx for the effort into reproducing this, it's tricky given it depends on other factors on the system than go and the source you are building but you nailed it with the docker file. :+1: :slightly_smiling_face:

Comment From: seankhliao

I suppose the answer is to use a recent version of gcc. ubuntu bionic is past EOL anyway.