CODEWITHSUNDEEP
linkerconfigureautotoolslibtool
Mike Kinghan
Mike Kinghan

Reputation: 61590

How to configure a non-standard linker for an autotooled build?

I wanted to configure an autotooled project to invoke a non-standard linker (the gold linker), using the stock autotools of Linux Mint 16/Ubuntu 13.10

I believed I would achieve this by:

However this has been ineffective. libtoolize has been successful. After a standard ./configure; make I now see that libtool is doing the linking:

/bin/bash ./libtool  --tag=CXX   --mode=link g++  -g -O2    -o helloworld helloworld.o

But passing LD=/path/to/my/linker to configure makes no difference. Experimentally, I even ran:

./configure LD=/does/not/exist

expecting to provoke an error, but I didn't. The output contains:

checking if the linker (/does/not/exist -m elf_x86_64) is GNU ld... no
checking whether the g++ linker (/does/not/exist -m elf_x86_64) supports shared libraries... yes

And thereafter a make continues to link, successfully, invoking g++ exactly as before.

What is the right way to configure a non-standard linker?

Upvotes: 5

Views: 4520

Answers (2)

asveikau
asveikau

Reputation: 40264

I landed on this via a Google search, though my scenario is a bit different from yours; there was no libtool involved. An old open source program's Makefile was hard-coding ld to create an object file with a symbol from binary data.

This is what I ended up doing to work around the lack of $(LD) being recognized when passed to configure:

https://github.com/turboencabulator/tuxnes/commit/bab2747b175ee7f2fc3d9afb28d69d82db054b5e

Basically I added to configure.ac:

AC_CHECK_TOOL([LD], [ld])

Leaving this answer here for if someone else lands via a google search.

Upvotes: 0

Employed Russian
Employed Russian

Reputation: 213877

But passing LD=/path/to/my/linker to configure makes no difference

This is because LD is almost never and should almost never be used to link any user-space program. Correct links are performed by using the appropriate compiler driver (gcc, g++, etc) instead.

What is the right way to configure a non-standard linker?

If you have /some/path/ld and you want gcc to use that ld, pass -B/some/path flag to gcc.

It then follows that you likely want:

./configure CC='gcc -B/some/path' CXX='g++ -B/some/path' ...

Upvotes: 3

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