cmd/link: suppress -bind_at_load deprecation warning for ld-prime

ld-prime emits a deprecation warning for -bind_at_load. The flag
is needed for plugins to not deadlock (#38824) when linking with
older darwin linker. It is supposedly not needed with newer linker
when chained fixups are used. For now, we always pass it, and
suppress the warning.

For #61229.

Change-Id: I4b8a6f864a460c40dc38adbb533f664f7fd5343c
Reviewed-on: https://go-review.googlesource.com/c/go/+/508696
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Cherry Mui <cherryyz@google.com>

diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
index de0a54d588bb1ff0abdb7e035088819c827331ca..c512d9a089e8aefbbdae0151bccac04097c81439 100644 (file)
--- a/src/cmd/link/internal/ld/lib.go
+++ b/src/cmd/link/internal/ld/lib.go
@@ -1903,6 +1903,16 @@ func (ctxt *Link) hostlink() {
                                out = append(out[:i], out[i+len(noPieWarning):]...)
                        }
                }
+               if ctxt.IsDarwin() {
+                       const bindAtLoadWarning = "ld: warning: -bind_at_load is deprecated on macOS\n"
+                       if i := bytes.Index(out, []byte(bindAtLoadWarning)); i >= 0 {
+                               // -bind_at_load is deprecated with ld-prime, but needed for
+                               // correctness with older versions of ld64. Swallow the warning.
+                               // TODO: maybe pass -bind_at_load conditionally based on C
+                               // linker version.
+                               out = append(out[:i], out[i+len(bindAtLoadWarning):]...)
+                       }
+               }
                ctxt.Logf("%s", out)
        }