[release-branch.go1.10] cmd/link: do not pass -no-pie to host linker when -linkshared...

As the comment above the code I'm changing says, when building with
-buildmode=exe, the default compiler flags produce code incompatible with PIE.
But when -linkshared is passed, the default compiler flags are not used so this
does not apply. And now I've found a system (linux/arm64 with glibc 2.27) where
this combination of flags causes a problem, albeit for reasons I don't really
understand, so stop passing -no-pie when -linkshared is passed.

Fixes golang/go#24873

Change-Id: I412ec7941dc0cb89e6d1b171fc29288aadcb9f20
Reviewed-on: https://go-review.googlesource.com/104815
Run-TryBot: Michael Hudson-Doyle <michael.hudson@canonical.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
(cherry picked from commit 2d26a65f8f1a6fcb0948803589061d99b94fa993)
Reviewed-on: https://go-review.googlesource.com/110035
Run-TryBot: Andrew Bonventre <andybons@golang.org>

diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
index 6dcaf64122f918c85d9e3bcb46d59e60dae38672..8a45825c65ef0f69aaa933a5945ccc734c9b3cad 100644 (file)
--- a/src/cmd/link/internal/ld/lib.go
+++ b/src/cmd/link/internal/ld/lib.go
@@ -1265,7 +1265,7 @@ func (ctxt *Link) hostlink() {
        // does not work, the resulting programs will not run. See
        // issue #17847. To avoid this problem pass -no-pie to the
        // toolchain if it is supported.
-       if ctxt.BuildMode == BuildModeExe {
+       if ctxt.BuildMode == BuildModeExe && !ctxt.linkShared {
                src := filepath.Join(*flagTmpdir, "trivial.c")
                if err := ioutil.WriteFile(src, []byte("int main() { return 0; }"), 0666); err != nil {
                        Errorf(nil, "WriteFile trivial.c failed: %v", err)