runtime/cgo: remove stdlib.h warning workaround on darwin

CL 205457 added the flag -Wno-nullability-completeness to work
around a user-reported build breakage on macOS Catalina.

However, according to
https://golang.org/issue/35247#issuecomment-589115489 the root cause
of the breakage may be a toolchain misconfiguration on the host
(perhaps compiling the XCode stdlib using a Homebrew build of the
"clang" compiler?).

Adding an obscure warning flag to enable building stdlib.h with an
otherwise-broken toolchain seems clearly inappropriate to me.
If need be we can instead provide guidance to users on how to unbreak
their toolchain.

Updates #35247
Fixes #49913

Change-Id: I84def34e101bed7911d8d78a991a29095b8791fa
Reviewed-on: https://go-review.googlesource.com/c/go/+/368634
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
Auto-Submit: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

diff --git a/src/runtime/cgo/cgo.go b/src/runtime/cgo/cgo.go
index 4d2caf6c4f326c8b618e6aed3eead6dae221cafc..8d72d792b1fac592c1037401e5d9dcd5719936f7 100644 (file)
--- a/src/runtime/cgo/cgo.go
+++ b/src/runtime/cgo/cgo.go
@@ -23,9 +23,6 @@ package cgo
 #cgo solaris LDFLAGS: -lxnet
 #cgo illumos LDFLAGS: -lsocket
 
-// Issue 35247.
-#cgo darwin CFLAGS: -Wno-nullability-completeness
-
 #cgo CFLAGS: -Wall -Werror
 
 #cgo solaris CPPFLAGS: -D_POSIX_PTHREAD_SEMANTICS