gbuild: introduce plugin (loader) concept

This introduces two concepts: a plugin and its loader (library)

LO currrently has dependency cycles for some libraries. There is
scui, which depends on sc, while sc dlopen's scui. There are the
various vclplug_* and the filters/gie libraries, which depends on
vcl and vcl dlopen's them. While the dependcies of the plugins on
their loader works fine, for static builds you must add a
dependency from the loader to the plugins, which introduces a
dependency cycle.

I codeified a few rules into the build system along with it:
* just plugins are allowed to depend / link other plugins
* plugins aren't allowed to be linked into the merge lib
* plugin loaders are "limited" to libraries

At the high level, this is implemented via two new gbuild calls:
* gb_Library_set_plugin_for,lib,loader: declare a library to be a
  plugin of a loader library
* gb_Helper_register_plugins_for_install: "plugin" replacement for
  gb_Helper_register_libraries_for_install to implement some
  additional checks in the build system

For the shared build, nothing changes. gb_Library_set_plugin_for is
just forwarded to gb_LinkTarget__use_libraries.

P.S. Android and iOS don't build their "executables" using gbuild,
but call bin/lo-all-static-libs to "let the linker figure it out".

P.P.S. the static handling isn't implemented in this commit, as it
turned out to be (very) much more complex.

Change-Id: I7b01d9c384cbc5838bd2cc93aff18e4868939d6e

14 files changed, 105 insertions, 27 deletions

diff --git a/Repository.mk b/Repository.mk
index 74b3967ca05b..7607fb1a5d12 100644
--- a/Repository.mk
+++ b/Repository.mk
@@ -252,12 +252,15 @@ $(eval $(call gb_Helper_register_libraries_for_install,OOOLIBS,calc, \
 	sc \
 	scd \
 	scfilt \
-	scui \
 	wpftcalc \
 	solver \
 	$(call gb_Helper_optional,SCRIPTING,vbaobj) \
 ))
 
+$(eval $(call gb_Helper_register_plugins_for_install,OOOLIBS,calc, \
+	scui \
+))
+
 $(eval $(call gb_Helper_register_libraries_for_install,OOOLIBS,graphicfilter, \
 	svgfilter \
 	wpftdraw \
@@ -280,19 +283,26 @@ $(eval $(call gb_Helper_register_libraries_for_install,OOOLIBS,onlineupdate, \
 
 $(eval $(call gb_Helper_register_libraries_for_install,OOOLIBS,gnome, \
 	$(if $(ENABLE_EVOAB2),evoab) \
-	$(if $(ENABLE_GTK3),vclplug_gtk3) \
 	$(if $(ENABLE_GIO),losessioninstall) \
 	$(if $(ENABLE_GIO),ucpgio1) \
 ))
 
+$(eval $(call gb_Helper_register_plugins_for_install,OOOLIBS,gnome, \
+    $(if $(ENABLE_GTK3),vclplug_gtk3) \
+))
+
 $(eval $(call gb_Helper_register_libraries_for_install,OOOLIBS,kde, \
 	$(if $(ENABLE_KF5),kf5be1) \
-	$(if $(USING_X11), \
-        $(if $(ENABLE_KF5),vclplug_kf5) \
-        $(if $(ENABLE_QT5),vclplug_qt5) \
-        $(if $(ENABLE_GTK3_KDE5),vclplug_gtk3_kde5) \
-	) \
 ))
+
+ifneq (,$(USING_X11))
+$(eval $(call gb_Helper_register_plugins_for_install,OOOLIBS,kde, \
+    $(if $(ENABLE_KF5),vclplug_kf5) \
+    $(if $(ENABLE_QT5),vclplug_qt5) \
+    $(if $(ENABLE_GTK3_KDE5),vclplug_gtk3_kde5) \
+))
+endif
+
 ifneq ($(ENABLE_GTK3_KDE5),)
 $(eval $(call gb_Helper_register_executables_for_install,OOO,kde, \
        lo_kde5filepicker \
@@ -300,7 +310,7 @@ $(eval $(call gb_Helper_register_executables_for_install,OOO,kde, \
 endif
 
 ifeq ($(OS),HAIKU)
-$(eval $(call gb_Helper_register_libraries_for_install,OOOLIBS,haiku, \
+$(eval $(call gb_Helper_register_plugins_for_install,OOOLIBS,haiku, \
     $(if $(ENABLE_QT5),vclplug_qt5) \
     $(if $(ENABLE_KF5),vclplug_kf5) \
 ))
@@ -406,7 +416,6 @@ $(eval $(call gb_Helper_register_libraries_for_install,OOOLIBS,ooo, \
 	sd \
 	sdd \
 	sdfilt \
-	sdui \
 	sfx \
 	simplecanvas \
 	slideshow \
@@ -451,14 +460,10 @@ $(eval $(call gb_Helper_register_libraries_for_install,OOOLIBS,ooo, \
 	xof \
 	xsltdlg \
 	xsltfilter \
-	$(if $(USING_X11), \
-		vclplug_gen \
-	) \
 	$(if $(filter $(OS),WNT), \
 		ado \
 		oleautobridge \
 		smplmail \
-		vclplug_win \
 		wininetbe1 \
 	) \
 	$(if $(filter $(OS),MACOSX), \
@@ -466,12 +471,19 @@ $(eval $(call gb_Helper_register_libraries_for_install,OOOLIBS,ooo, \
 			AppleRemote \
 		) \
 		fps_aqua \
-		vclplug_osx \
 	) \
 	$(if $(filter iOS MACOSX,$(OS)), \
 		MacOSXSpell \
 	) \
-	$(if $(filter EMSCRIPTEN,$(OS)),vclplug_qt5) \
+))
+
+$(eval $(call gb_Helper_register_plugins_for_install,OOOLIBS,ooo, \
+    gie \
+    sdui \
+    $(if $(USING_X11),vclplug_gen) \
+    $(if $(filter $(OS),WNT),vclplug_win) \
+    $(if $(filter $(OS),MACOSX),vclplug_osx) \
+    $(if $(filter EMSCRIPTEN,$(OS)),vclplug_qt5) \
 ))
 
 $(eval $(call gb_Helper_register_libraries_for_install,OOOLIBS,postgresqlsdbc, \
@@ -510,7 +522,6 @@ $(eval $(call gb_Helper_register_libraries_for_install,OOOLIBS,writer, \
 	$(if $(ENABLE_LWP),lwpft) \
 	msword \
 	swd \
-	swui \
 	t602filter \
 	$(call gb_Helper_optional,SCRIPTING,vbaswobj) \
 	wpftwriter \
@@ -518,6 +529,10 @@ $(eval $(call gb_Helper_register_libraries_for_install,OOOLIBS,writer, \
 	$(call gb_Helper_optional,DBCONNECTIVITY,writer) \
 ))
 
+$(eval $(call gb_Helper_register_plugins_for_install,OOOLIBS,writer, \
+	swui \
+))
+
 # cli_cppuhelper is NONE even though it is actually in URE because it is CliNativeLibrary
 $(eval $(call gb_Helper_register_libraries,PLAINLIBS_NONE, \
 	smoketest \
diff --git a/sc/Library_scui.mk b/sc/Library_scui.mk
index 86605ab63a0d..4d4cffa12bd4 100644
--- a/sc/Library_scui.mk
+++ b/sc/Library_scui.mk
@@ -9,6 +9,8 @@
 
 $(eval $(call gb_Library_Library,scui))
 
+$(eval $(call gb_Library_set_plugin_for,scui,sc))
+
 $(eval $(call gb_Library_set_include,scui,\
 	-I$(SRCDIR)/sc/source/core/inc \
 	-I$(SRCDIR)/sc/source/filter/inc \
@@ -55,7 +57,6 @@ $(eval $(call gb_Library_use_libraries,scui,\
 	$(call gb_Helper_optional,OPENCL, \
 		opencl) \
 	sal \
-	sc \
 	sfx \
 	sot \
 	svl \
diff --git a/sd/Library_sdui.mk b/sd/Library_sdui.mk
index c776e2eed532..a774d0610cb4 100644
--- a/sd/Library_sdui.mk
+++ b/sd/Library_sdui.mk
@@ -9,6 +9,8 @@
 
 $(eval $(call gb_Library_Library,sdui))
 
+$(eval $(call gb_Library_set_plugin_for,sdui,sd))
+
 $(eval $(call gb_Library_set_include,sdui,\
     $$(INCLUDE) \
     -I$(SRCDIR)/sd/inc \
@@ -49,7 +51,6 @@ $(eval $(call gb_Library_use_libraries,sdui,\
     fwk \
     sal \
     salhelper \
-    sd \
     sfx \
     sot \
     svl \
diff --git a/solenv/gbuild/Helper.mk b/solenv/gbuild/Helper.mk
index 2aa0fc8d65b2..2367a8ba9a91 100644
--- a/solenv/gbuild/Helper.mk
+++ b/solenv/gbuild/Helper.mk
@@ -199,6 +199,13 @@ $(if $(filter UNOVERLIBS RTVERLIBS,$(1)),\
 
 endef
 
+# a plugin is a library, why can't be dynamically linked and must be dlopen'd, but must be linked static
+define gb_Helper_register_plugins_for_install
+$(call gb_Helper_register_libraries_for_install,$(1),$(2),$(3))
+gb_Library_KNOWNPLUGINS += $(3)
+
+endef
+
 define gb_Helper__register_jars
 $(foreach group,$(gb_Jar_VALIDGROUPS),\
  $(foreach target,$(2),\
diff --git a/solenv/gbuild/Library.mk b/solenv/gbuild/Library.mk
index 8c3c2207480d..8883262025af 100644
--- a/solenv/gbuild/Library.mk
+++ b/solenv/gbuild/Library.mk
@@ -162,6 +162,18 @@ gb_Library__COMPONENTPREFIXES := \
 
 gb_Library_get_runtime_filename = $(call gb_Library_get_filename,$(1))
 
+# call gb_Library_set_plugin_for,library,loader
+define gb_Library_set_plugin_for
+ifneq (,$$(filter-out $(gb_Library_KNOWNPLUGINS),$(1)))
+$$(eval $$(call gb_Output_info,currently known plugins are: $(sort $(gb_Library_KNOWNPLUGINS)),ALL))
+$$(eval $$(call gb_Output_error,Unknown plugin(s) '$$(filter-out $(gb_Library_KNOWNPLUGINS),$(1)))'. Plugins must be registered in Repository.mk or RepositoryExternal.mk))
+endif
+
+$(call gb_LinkTarget_get_target,$(call gb_Library_get_linktarget,$(2))) : PLUGINS += $(1)
+$(eval $(call gb_LinkTarget__add_plugin,$(call gb_Library_get_linktarget,$(2)),$(1)))
+$(call gb_Library__forward_to_Linktarget,$(0),$(1),$(2),$(3))
+endef
+
 # forward the call to the gb_LinkTarget implementation
 # (note: because the function name is in $(1), the other args are shifted by 1)
 define gb_Library__forward_to_Linktarget
diff --git a/solenv/gbuild/LinkTarget.mk b/solenv/gbuild/LinkTarget.mk
index 6cd8719f91b7..fdd74c4887b8 100644
--- a/solenv/gbuild/LinkTarget.mk
+++ b/solenv/gbuild/LinkTarget.mk
@@ -1041,6 +1041,7 @@ ifeq ($(DISABLE_DYNLOADING),)
 $(call gb_LinkTarget_get_target,$(1)) : \
 	$(foreach lib,$(3),$(call gb_Library_get_exports_target,$(lib)))
 endif
+
 $(call gb_LinkTarget_get_headers_target,$(1)) : \
 	$(foreach lib,$(2),$(call gb_Library_get_headers_target,$(lib)))
 $(foreach lib,$(2),$(call gb_LinkTarget__lib_dummy_depend,$(lib)))
@@ -1089,7 +1090,12 @@ endef
 define gb_LinkTarget_use_libraries
 ifneq (,$$(filter-out $(gb_Library_KNOWNLIBS),$(2)))
 $$(eval $$(call gb_Output_info,currently known libraries are: $(sort $(gb_Library_KNOWNLIBS)),ALL))
-$$(eval $$(call gb_Output_error,Cannot link against library/libraries $$(filter-out $(gb_Library_KNOWNLIBS),$(2)). Libraries must be registered in Repository.mk or RepositoryExternal.mk))
+$$(eval $$(call gb_Output_error,Cannot link against library/libraries '$$(filter-out $(gb_Library_KNOWNLIBS),$(2))'. Libraries must be registered in Repository.mk or RepositoryExternal.mk))
+endif
+ifneq (,$$(filter $(2),$(gb_Library_KNOWNPLUGINS)))
+ifneq (,$$(filter $(1),$$(foreach plugin,$(gb_Library_KNOWNPLUGINS),$(call gb_Library__get_workdir_linktargetname,$(plugin)))))
+$$(eval $$(call gb_Output_error,Cannot link against plugin library/libraries '$$(filter $(2),$(gb_Library_KNOWNPLUGINS))'. Only plugins are allowed to do that.))
+endif
 endif
 
 ifeq ($(call gb_LinkTarget__is_build_tool,$(1)),$(true))
@@ -1789,5 +1795,33 @@ $(call gb_LinkTarget_get_target,$(1)) : T_USE_LD := $(or $(CLANG_USE_LD),$(USE_L
 
 endef
 
+gb_LinkTarget__get_plugins_var = $(call gb_LinkTarget__get_workdir_linktargetname,$(1))<>PLUGINS
+gb_LinkTarget__get_plugins = $($(call gb_LinkTarget__get_plugins_var,$(1)))
+gb_Library__get_plugins = $($(call gb_LinkTarget__get_plugins_var,$(call gb_Library_get_linktarget,$(1))))
+
+define gb_LinkTarget__add_plugin
+$(call gb_LinkTarget__get_plugins_var,$(1)) += $(2)
+
+endef
+
+# call gb_LinkTarget__set_plugin_for,linktarget,loader
+define gb_LinkTarget__set_plugin_for
+ifneq (,$$(filter-out $(gb_Library_KNOWNLIBS),$(2)))
+$$(eval $$(call gb_Output_info,currently known libraries are: $(sort $(gb_Library_KNOWNLIBS)),ALL))
+$$(eval $$(call gb_Output_error,Cannot link against library/libraries $$(filter-out $(gb_Library_KNOWNLIBS),$(2)). Libraries must be registered in Repository.mk or RepositoryExternal.mk))
+endif
+ifeq (,$(filter $(1),$(foreach plugin,$(gb_Library_KNOWNPLUGINS),$(call gb_Library_get_linktarget,$(plugin)))))
+$$(eval $$(call gb_Output_error,Unknown plugin(s) '$(filter $(1),$(foreach plugin,$(gb_Library_KNOWNPLUGINS),$(call gb_Library_get_linktarget,$(plugin))))'. Plugins must be registered in Repository.mk or RepositoryExternal.mk))
+endif
+ifeq (,$(filter $(1),$(foreach lib,$(gb_MERGEDLIBS),$(call gb_Library_get_linktarget,$(lib)))))
+$$(eval $$(call gb_Output_error,Plugins can't be in mergelibs))
+endif
+ifeq ($(call gb_LinkTarget__is_build_tool,$(1)),$(true))
+$$(eval $$(call gb_Output_error,Plugin support for build tools not implemented))
+endif
+
+$(call gb_LinkTarget__use_libraries,$(1),$(2),$(2))
+
+endef
 
 # vim: set noet sw=4:
diff --git a/sw/Library_swui.mk b/sw/Library_swui.mk
index 99f1dd20ae3d..e643179d355f 100644
--- a/sw/Library_swui.mk
+++ b/sw/Library_swui.mk
@@ -19,6 +19,8 @@
 
 $(eval $(call gb_Library_Library,swui))
 
+$(eval $(call gb_Library_set_plugin_for,swui,sw))
+
 $(eval $(call gb_Library_set_include,swui,\
     -I$(SRCDIR)/sw/inc \
     -I$(SRCDIR)/sw/source/uibase/inc \
@@ -69,7 +71,6 @@ $(eval $(call gb_Library_use_libraries,swui,\
     svx \
     svx \
     svxcore \
-    sw \
     tk \
     tl \
     ucbhelper \
diff --git a/vcl/Library_vclplug_gen.mk b/vcl/Library_vclplug_gen.mk
index 3ebf80034c91..73f5464d7362 100644
--- a/vcl/Library_vclplug_gen.mk
+++ b/vcl/Library_vclplug_gen.mk
@@ -19,6 +19,8 @@
 
 $(eval $(call gb_Library_Library,vclplug_gen))
 
+$(eval $(call gb_Library_set_plugin_for,vclplug_gen,vcl))
+
 $(eval $(call gb_Library_set_include,vclplug_gen,\
     $$(INCLUDE) \
     -I$(SRCDIR)/vcl/inc \
@@ -33,7 +35,6 @@ $(eval $(call gb_Library_use_sdk_api,vclplug_gen))
 $(eval $(call gb_Library_use_common_precompiled_header,vclplug_gen))
 
 $(eval $(call gb_Library_use_libraries,vclplug_gen,\
-    vcl \
     tl \
     utl \
     sot \
diff --git a/vcl/Library_vclplug_gtk3.mk b/vcl/Library_vclplug_gtk3.mk
index 44d742e01c77..27eb13821bb3 100644
--- a/vcl/Library_vclplug_gtk3.mk
+++ b/vcl/Library_vclplug_gtk3.mk
@@ -19,6 +19,8 @@
 
 $(eval $(call gb_Library_Library,vclplug_gtk3))
 
+$(eval $(call gb_Library_set_plugin_for,vclplug_gtk3,vcl))
+
 # Silence deprecation warnings wholesale as long as vcl/unx/gtk3/*.cxx just
 # forward to vcl/unx/gtk/*.cxx:
 $(eval $(call gb_Library_add_cxxflags,vclplug_gtk3, \
@@ -54,7 +56,6 @@ $(eval $(call gb_Library_add_libs,vclplug_gtk3,\
 ))
 
 $(eval $(call gb_Library_use_libraries,vclplug_gtk3,\
-    vcl \
     svl \
     tl \
     utl \
diff --git a/vcl/Library_vclplug_gtk3_kde5.mk b/vcl/Library_vclplug_gtk3_kde5.mk
index ab804e76a697..68a3ca8809c7 100644
--- a/vcl/Library_vclplug_gtk3_kde5.mk
+++ b/vcl/Library_vclplug_gtk3_kde5.mk
@@ -19,6 +19,8 @@
 
 $(eval $(call gb_Library_Library,vclplug_gtk3_kde5))
 
+$(eval $(call gb_Library_set_plugin_for,vclplug_gtk3_kde5,vcl))
+
 # Silence deprecation warnings wholesale as long as vcl/unx/gtk3/*.cxx just
 # forward to vcl/unx/gtk/*.cxx:
 $(eval $(call gb_Library_add_cxxflags,vclplug_gtk3_kde5, \
@@ -60,7 +62,6 @@ $(eval $(call gb_Library_add_libs,vclplug_gtk3_kde5,\
 
 $(eval $(call gb_Library_use_libraries,vclplug_gtk3_kde5,\
     svl \
-    vcl \
     tl \
     utl \
     sot \
diff --git a/vcl/Library_vclplug_kf5.mk b/vcl/Library_vclplug_kf5.mk
index d10cecd167d5..1e7765a6d6ce 100644
--- a/vcl/Library_vclplug_kf5.mk
+++ b/vcl/Library_vclplug_kf5.mk
@@ -19,6 +19,8 @@
 
 $(eval $(call gb_Library_Library,vclplug_kf5))
 
+$(eval $(call gb_Library_set_plugin_for,vclplug_kf5,vcl))
+
 $(eval $(call gb_Library_use_custom_headers,vclplug_kf5,vcl/unx/kf5))
 
 $(eval $(call gb_Library_set_include,vclplug_kf5,\
@@ -35,7 +37,6 @@ $(eval $(call gb_Library_use_sdk_api,vclplug_kf5))
 
 $(eval $(call gb_Library_use_libraries,vclplug_kf5,\
     vclplug_qt5 \
-    vcl \
     tl \
     utl \
     sot \
diff --git a/vcl/Library_vclplug_osx.mk b/vcl/Library_vclplug_osx.mk
index c80d3bc8d7f3..5cb854343df6 100644
--- a/vcl/Library_vclplug_osx.mk
+++ b/vcl/Library_vclplug_osx.mk
@@ -19,6 +19,8 @@
 
 $(eval $(call gb_Library_Library,vclplug_osx))
 
+$(eval $(call gb_Library_set_plugin_for,vclplug_osx,vcl))
+
 $(eval $(call gb_Library_set_include,vclplug_osx,\
     $$(INCLUDE) \
     -I$(SRCDIR)/vcl/inc \
@@ -51,7 +53,6 @@ $(eval $(call gb_Library_use_libraries,vclplug_osx,\
     sal \
     salhelper \
     tl \
-    vcl \
 ))
 
 $(eval $(call gb_Library_use_externals,vclplug_osx,\
diff --git a/vcl/Library_vclplug_qt5.mk b/vcl/Library_vclplug_qt5.mk
index b7ea9acdb08e..a91841ec32e4 100644
--- a/vcl/Library_vclplug_qt5.mk
+++ b/vcl/Library_vclplug_qt5.mk
@@ -19,6 +19,8 @@
 
 $(eval $(call gb_Library_Library,vclplug_qt5))
 
+$(eval $(call gb_Library_set_plugin_for,vclplug_qt5,vcl))
+
 $(eval $(call gb_Library_use_custom_headers,vclplug_qt5,vcl/qt5))
 
 $(eval $(call gb_Library_set_include,vclplug_qt5,\
@@ -36,7 +38,6 @@ $(eval $(call gb_Library_add_defs,vclplug_qt5,\
 $(eval $(call gb_Library_use_sdk_api,vclplug_qt5))
 
 $(eval $(call gb_Library_use_libraries,vclplug_qt5,\
-    vcl \
     tl \
     utl \
     sot \
diff --git a/vcl/Library_vclplug_win.mk b/vcl/Library_vclplug_win.mk
index ca75300670b3..2fd00d7bd03b 100644
--- a/vcl/Library_vclplug_win.mk
+++ b/vcl/Library_vclplug_win.mk
@@ -19,6 +19,8 @@
 
 $(eval $(call gb_Library_Library,vclplug_win))
 
+$(eval $(call gb_Library_set_plugin_for,vclplug_win,vcl))
+
 $(eval $(call gb_Library_set_componentfile,vclplug_win,vcl/vclplug_win))
 
 $(eval $(call gb_Library_set_include,vclplug_win,\
@@ -53,7 +55,6 @@ $(eval $(call gb_Library_use_libraries,vclplug_win,\
     salhelper \
     tl \
     utl \
-    vcl \
 ))
 
 $(eval $(call gb_Library_use_externals,vclplug_win,\