Make odk build-examples work on macOS 10.15

...which apparently got even stricter with unsetting DYLD_LIBRARY_PATH when
starting a shell, so the old workaround from
9ac2aad4c1cd0f8d513c02a897da90c42f2fa961 "OSX fix ODK example builds with
enabled SIP" no longer worked for me (and CustomTarget_odk/build-examples_java
failed with

> dyld: Library not loaded: @__VIA_LIBRARY_PATH__/libreglo.dylib
>   Referenced from: /Users/stephan/Software/lo/core/instdir/LibreOffice6.4_SDK/bin/idlc
>   Reason: image not found

).  Building on macOS 10.15 now requires to build a shell from upstream sources
and pass it into toplevel make as a SHELL=... command line argument (but which I
at least already needed to do anyway, to preserve a global DYLD_LIBRARY_PATH
pointing at a nonstandard libc++, when building external/firebird).

Change-Id: I00ec0649fafa1842bed3f2a1258e3184d6bcfdd1
Reviewed-on: https://gerrit.libreoffice.org/80532
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

1 files changed, 21 insertions, 4 deletions

diff --git a/odk/build-examples_common.mk b/odk/build-examples_common.mk
index 4d7d645ed40a..50ea40ec905e 100644
--- a/odk/build-examples_common.mk
+++ b/odk/build-examples_common.mk
@@ -11,6 +11,23 @@ define odk_build-examples_test
 
 $(eval $(call gb_CustomTarget_CustomTarget,$(1)))
 
+# System-provided shells on macOS are known to unset DYLD_LIBRARY_PATH, so we need some sort of hack
+# to provided the invocation of make below with a shell that preserves DYLD_LIBRARY_PATH.  Until
+# macOS 10.14, what apparently worked is to use a copy of /bin/sh in some temp dir.  However, with
+# macOS 10.15, that hack appears to no longer work, the only known workaround is to use e.g. bash
+# built from upstream source and pass it into the toplevel make invocation as SHELL=... command line
+# argument (which is also needed when building external/firebird and needing to preserve a global
+# DYLD_LIBRARY_PATH, see comment 17 at
+# <https://bugs.documentfoundation.org/show_bug.cgi?id=101789#c17> "FIREBIRD 3 - fails to build on
+# OSX 10.11.6 with clang").  When building on macOS <= 10.14 and not passing SHELL=... on the
+# command line, MACOSX_SHELL_HACK will kick in and do the "use a copy of /bin/sh" workaround.  When
+# passing in a self-built SHELL=... (which is necessary now on macOS >= 10.15), the
+# MACOSX_SHELL_HACK will not kick in, but the below invocation of make will automatically inherit
+# SHELL from the currently running invocation of make.  (At least with GNU Make 4.2.1, the origin of
+# a default SHELL setting is, somewhat unintuitively, reported as "file" rather than "default".  To
+# avoid surprises, use an explicit check for an origin of "command line" here.)
+MACOSX_SHELL_HACK := $(and $(filter MACOSX,$(OS)),$(filter-out command line,$(origin SHELL)))
+
 $(call gb_CustomTarget_get_target,$(1)): \
 	$(call gb_CustomTarget_get_workdir,$(1))/setsdkenv
 ifneq ($(gb_SUPPRESS_TESTS),)
@@ -18,7 +35,7 @@ ifneq ($(gb_SUPPRESS_TESTS),)
 else
 	$$(call gb_Output_announce,$(subst $(WORKDIR)/,,$(1)),$(true),CHK,1)
 	rm -fr $(call gb_CustomTarget_get_workdir,$(1))/{out,user}
-ifeq (MACOSX,$(OS))
+ifneq ($(MACOSX_SHELL_HACK),)
 	$(eval ODK_BUILD_SHELL := $(shell $(gb_MKTEMP)))
 	cp /bin/sh "$(ODK_BUILD_SHELL)"
 	chmod 0700 "$(ODK_BUILD_SHELL)"
@@ -32,13 +49,13 @@ endif
 	    && (cd $(INSTDIR)/$(SDKDIRNAME)/examples/$(my_dir) \
 		&& printf 'yes\n' | LC_ALL=C make \
 			CC="$(CXX)" LINK="$(CXX)" LIB="$(CXX)" \
-		    $(if $(filter MACOSX,$(OS)), SHELL=$(ODK_BUILD_SHELL), )))) \
+		    $(if $(MACOSX_SHELL_HACK), SHELL=$(ODK_BUILD_SHELL), )))) \
 	    >$(call gb_CustomTarget_get_workdir,$(1))/log 2>&1 \
 	|| (RET=$$$$? \
-	    $(if $(filter MACOSX,$(OS)), && rm -f $(ODK_BUILD_SHELL) , ) \
+	    $(if $(MACOSX_SHELL_HACK), && rm -f $(ODK_BUILD_SHELL) , ) \
 	    && cat $(call gb_CustomTarget_get_workdir,$(1))/log \
 	    && exit $$$$RET)
-ifeq (MACOSX,$(OS))
+ifneq ($(MACOSX_SHELL_HACK),)
 	-rm -f $(ODK_BUILD_SHELL)
 endif
 endif