From 0d4e2a3275092289ca0b2d4a6904c065dc2ef835 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Fri, 4 Nov 2016 05:05:22 -0600
Subject: [PATCH] configure: add `-Wno-nullability-completeness` for xform
 output

Mac OS X header files for 10.12 include `_Nullable` and `_Nonnull`
annotations. When those appear in xform output, they're no longer
counted as being in system headers, and so nullability
completeness is enabled. Disable is explicitly when the flag is
supported.
---
 racket/src/configure           | 31 +++++++++++++++++++++++++++++++
 racket/src/racket/configure.ac | 20 ++++++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/racket/src/configure b/racket/src/configure
index 6f66522ed4..24b1245bf4 100755
--- a/racket/src/configure
+++ b/racket/src/configure
@@ -3218,6 +3218,7 @@ use_flag_pthread=yes
 use_flag_posix_pthread=no
 skip_iconv_check=no
 check_page_size=yes
+try_no_nullability_completeness=no
 
 MAKE_LOCAL_RACKET=no-local-racket
 
@@ -4828,6 +4829,12 @@ fi
     # and that breaks static allocation of fd_sets
     try_poll_syscall=yes
 
+    # -pthread is not needed and triggers a warning
+    use_flag_pthread=no
+
+    # Use -Wno-nullability-completeness if supported
+    try_no_nullability_completeness=yes
+
     # ".a" is typically not useful, since we always build a ".dylib":
     if test "${enable_libs}" == "" ; then
       INSTALL_LIBS_ENABLE=no-install
@@ -5871,6 +5878,30 @@ if test "${LFS_CFLAGS}" != "" && test "${LFS_CFLAGS}" != "undefined"; then
   MZOPTIONS="${MZOPTIONS} ${LFS_CFLAGS}"
 fi
 
+if test "${try_no_nullability_completeness}" = "yes" ; then
+   msg="for -Wno-nullability-completeness"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking $msg" >&5
+$as_echo_n "checking $msg... " >&6; }
+  OLD_CFLAGS="${CFLAGS}"
+  CFLAGS="${CFLAGS}  -Wno-nullability-completeness"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+int main() { return 0; }
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  nonullcomp=yes
+else
+  nonullcomp=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  if test "$nonullcomp" = "yes" ; then
+    GC2OPTIONS="$GC2OPTIONS -Wno-nullability-completeness"
+  fi
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $nonullcomp" >&5
+$as_echo "$nonullcomp" >&6; }
+  CFLAGS="${OLD_CFLAGS}"
+fi
+
 ###### Get data sizes, stack direction, and endianness #######
 
 # The cast to long int works around a bug in the HP C Compiler
diff --git a/racket/src/racket/configure.ac b/racket/src/racket/configure.ac
index b079501037..085c450650 100644
--- a/racket/src/racket/configure.ac
+++ b/racket/src/racket/configure.ac
@@ -474,6 +474,7 @@ use_flag_pthread=yes
 use_flag_posix_pthread=no
 skip_iconv_check=no
 check_page_size=yes
+try_no_nullability_completeness=no
 
 MAKE_LOCAL_RACKET=no-local-racket
 
@@ -894,6 +895,12 @@ case "$host_os" in
     # and that breaks static allocation of fd_sets
     try_poll_syscall=yes
 
+    # -pthread is not needed and triggers a warning
+    use_flag_pthread=no
+
+    # Use -Wno-nullability-completeness if supported
+    try_no_nullability_completeness=yes
+
     # ".a" is typically not useful, since we always build a ".dylib":
     if test "${enable_libs}" == "" ; then
       INSTALL_LIBS_ENABLE=no-install
@@ -1323,6 +1330,19 @@ if test "${LFS_CFLAGS}" != "" && test "${LFS_CFLAGS}" != "undefined"; then
   MZOPTIONS="${MZOPTIONS} ${LFS_CFLAGS}"  
 fi
 
+if test "${try_no_nullability_completeness}" = "yes" ; then
+  [ msg="for -Wno-nullability-completeness" ]
+  AC_MSG_CHECKING($msg)
+  OLD_CFLAGS="${CFLAGS}"
+  CFLAGS="${CFLAGS}  -Wno-nullability-completeness"
+  AC_COMPILE_IFELSE([AC_LANG_SOURCE([int main() { return 0; }])], nonullcomp=yes, nonullcomp=no)
+  if test "$nonullcomp" = "yes" ; then
+    GC2OPTIONS="$GC2OPTIONS -Wno-nullability-completeness"
+  fi
+  AC_MSG_RESULT($nonullcomp)  
+  CFLAGS="${OLD_CFLAGS}"
+fi
+
 ###### Get data sizes, stack direction, and endianness #######
 
 AC_CHECK_SIZEOF(char)