How to use relative path for LDFLAGS in golang

Question

I am trying to create a golang program that uses a static library (.a file)

directory structure for my project as below

└─testserver ├─bin ├─pkg └─src ├─logging └─testserver ├─libtest.a └─test.go 

flags for cgo in test.go as below

 // #cgo LDFLAGS: -L /home/test/testserver/src/testserver -ltest // #include "test.h" import "C" 

when I use the absolute path for LDFLAGS -L, it works fine, but when I change the path to a relative path, for example

 // #cgo LDFLAGS: -L ./testserver -ltest 

and then run the command

 go install testserver 

he returns me an error and says that he "cannot find the -L test"

my question is, how can I use the relative path in LDFLAGS ?, so that I can build the project in any path.

Answer 1

You cannot currently. The directory changes between the moment the command was created and the binding. For now, you either need to reference the absolute path, or use the CGO_LDFLAGS environment CGO_LDFLAGS .

It was fixed immediately after go1.4, which added the variable ${SRCDIR} , which is replaced by the absolute path to the directory containing the source file during assembly. https://github.com/golang/go/issues/7891 . It will be in go1.5 and you can easily use it now by building Go from source.

Answer 2

It is very useful to use $ {SRCDIR} to solve the relative path problem.

In addition, $ {SRCDIR} indicates the absolute path of the current go file . Use the go build -x . command go build -x . to verify the output.

 $ go build -x . ... cd /root/sourcecode/src/tcp/aes CGO_LDFLAGS="-g" "-O2" "-L/root/sourcecode/src/tcp/aes/aes" "-laes" /usr/local/go/pkg/tool/linux_amd64/cgo -objdir $WORK/tcp/aes/_obj/ -importpath tcp/aes -- -I $WORK/tcp/aes/_obj/ aes.go cd $WORK ... $ tcp/aes /usr/bin/ld: cannot find -laes collect2: error: ld returned 1 exit status 

This is incrrect because lib libaes.a finds the same thing as the go file. Then I changed it and went through.