From 1b5e8b408eb9014d0779515705a601debd22ba56 Mon Sep 17 00:00:00 2001
From: Tom Lane
Date: Fri, 2 Nov 2018 18:54:00 -0400
Subject: Yet further rethinking of build changes for macOS Mojave.

The solution arrived at in commit e74dd00f5 presumes that the compiler
has a suitable default -isysroot setting ... but further experience
shows that in many combinations of macOS version, XCode version, Xcode
command line tools version, and phase of the moon, Apple's compiler
will *not* supply a default -isysroot value.

We could potentially go back to the approach used in commit 68fc227dd,
but I don't have a lot of faith in the reliability or life expectancy of
that either.  Let's just revert to the approach already shipped in 11.0,
namely specifying an -isysroot switch globally.  As a partial response to
the concerns raised by Jakob Egger, adjust the contents of Makefile.global
to look like

CPPFLAGS = -isysroot $(PG_SYSROOT) ...
PG_SYSROOT = /path/to/sysroot

This allows overriding the sysroot path at build time in a relatively
painless way.

Add documentation to installation.sgml about how to use the PG_SYSROOT
option.  I also took the opportunity to document how to work around
macOS's "System Integrity Protection" feature.

As before, back-patch to all supported versions.

Discussion: https://postgr.es/m/20840.1537850987@sss.pgh.pa.us
---
 src/Makefile.global.in | 1 +
 src/template/darwin    | 7 ++++---
 2 files changed, 5 insertions(+), 3 deletions(-)

(limited to 'src')

diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index 363b643f722..be22885f400 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -226,6 +226,7 @@ PTHREAD_LIBS		= @PTHREAD_LIBS@
 
 CPP = @CPP@
 CPPFLAGS = @CPPFLAGS@
+PG_SYSROOT = @PG_SYSROOT@
 
 ifdef PGXS
 override CPPFLAGS := -I$(includedir_server) -I$(includedir_internal) $(CPPFLAGS)
diff --git a/src/template/darwin b/src/template/darwin
index 159d8bb1275..c05adca0bfb 100644
--- a/src/template/darwin
+++ b/src/template/darwin
@@ -3,14 +3,15 @@
 # Note: Darwin is the original code name for macOS, also known as OS X.
 # We still use "darwin" as the port name, partly because config.guess does.
 
-# Some configure tests require explicit knowledge of where the Xcode "sysroot"
-# is.  We try to avoid having this leak into configure's results, though.
+# Select where system include files should be sought.
 if test x"$PG_SYSROOT" = x"" ; then
   PG_SYSROOT=`xcodebuild -version -sdk macosx Path 2>/dev/null`
 fi
 # Old xcodebuild versions may produce garbage, so validate the result.
 if test x"$PG_SYSROOT" != x"" ; then
-  if test \! -d "$PG_SYSROOT" ; then
+  if test -d "$PG_SYSROOT" ; then
+    CPPFLAGS="-isysroot $PG_SYSROOT $CPPFLAGS"
+  else
     PG_SYSROOT=""
   fi
 fi
-- 
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