cmd/link: some packages don't build with -buildmode=shared
pebbe opened this issue · comments
Please answer these questions before submitting your issue. Thanks!
What version of Go are you using (go version
)?
go version go1.9.5 linux/amd64
go version go1.10.1 linux/amd64
Does this issue reproduce with the latest release?
yes
What operating system and processor architecture are you using (go env
)?
GOARCH="amd64"
GOBIN=""
GOCACHE="/tmp/go-build"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/peter/go"
GORACE=""
GOROOT="/my/opt/go"
GOTMPDIR="/tmp"
GOTOOLDIR="/my/opt/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
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-build569417713=/tmp/go-build -gno-record-gcc-switches"
What did you do?
I tried to install the package github.com/pebbe/util
in lgo (github.com/yunabe/lgo
). The package installs and works fine as a regular, static package. But lgo tries to build shared packages, and that fails.
I don't know what is going on, but this might be a bug in Go with -buildmode=shared
You can find a detailed description here: yunabe/lgo#57
I created a repository to reproduce this issue with minimum code
https://github.com/yunabe/gobug25065
cmd/link
fails when a method A
is defined as func (m myType) A() {}
and it is referenced by (*myType).A
.
CC @mwhudson
Hm my fix for #22998 doesn't seem to fix this. Will need to make some time to dig properly into this.
If I run
go tool compile -shared -o foo.a GOPATH/github.com/yunabe/gobug25065/src.go
then go tool nm
shows
1187 R %22%22.(*myType).A·f
If I run
go tool compile -shared -dynlink -o foo.a GOPATH/github.com/yunabe/gobug25065/src.go
(that is, add the -dynlink
option) then go tool nm
shows
U %22%22.(*myType).A·f
So it seems that when using -dynlink
the symbol really is undefined.
Change https://golang.org/cl/153297 mentions this issue: cmd/compile: emit a symbol for a method expression when using -dynlink