initial support for clang compiler plugins

The plugin is intentionally built using a custom Makefile,
because it's used by gbuild, so I don't want to build the plugin
using gbuild too. It is also intentionally not placed under workdir/,
as that is cleaned by 'make clean', the plugin is cleaned only
by 'make distclean', so that cleaning it doesn't cause ccache misses.
No actual functionality in the plugin itself yet.

Change-Id: Ic05eba8d6260eec123c9e699eb5385abfe1b832f

1 files changed, 60 insertions, 0 deletions

diff --git a/compilerplugins/Makefile-clang.mk b/compilerplugins/Makefile-clang.mk
new file mode 100644
index 000000000000..1797e424ddb1
--- /dev/null
+++ b/compilerplugins/Makefile-clang.mk
@@ -0,0 +1,60 @@
+#
+# This file is part of the LibreOffice project.
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+
+# Make sure variables in this Makefile do not conflict with other variables (e.g. from gbuild).
+
+# The list of source files.
+CLANGSRC=compileplugin.cxx
+
+# You may occassionally want to override some of these
+
+# Compile flags ('make CLANGCXXFLAGS=-g' if you need to debug the plugin)
+CLANGCXXFLAGS=-O2 -Wall -g
+# The prefix where Clang resides, override to where Clang resides if using a source build.
+CLANGDIR=/usr
+# The build directory (different from CLANGDIR if using a Clang out-of-source build)
+CLANGBUILD=/usr
+
+# The uninteresting rest.
+
+# Clang headers require these.
+CLANGDEFS=-D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -fno-rtti
+# All include locations needed.
+CLANGINCLUDES=-I$(CLANGDIR)/include -I$(CLANGDIR)/tools/clang/include -I$(CLANGBUILD)/include -I$(CLANGBUILD)/tools/clang/include
+
+CLANGINDIR=$(SRCDIR)/compilerplugins/clang
+# Cannot use $(WORKDIR), the plugin should survive even 'make clean', otherwise the rebuilt
+# plugin will cause cache misses with ccache.
+CLANGOUTDIR=$(SRCDIR)/compilerplugins/obj
+
+compilerplugins: $(CLANGOUTDIR) $(CLANGOUTDIR)/compileplugin.so
+
+compilerplugins-clean:
+	rm -rf $(CLANGOUTDIR)
+
+$(CLANGOUTDIR):
+	mkdir -p $(CLANGOUTDIR)
+
+CLANGOBJS=
+
+define clangbuildsrc
+$(3): $(2) $(SRCDIR)/compilerplugins/Makefile-clang.mk
+	$(CXX) $(CLANGCXXFLAGS) $(CLANGDEFS) $(CLANGINCLUDES) $(2) -fPIC -c -o $(3) -MMD -MT $(3) -MP -MF $(CLANGOUTDIR)/$(1).d
+
+-include $(CLANGOUTDIR)/$(1).d
+
+$(CLANGOUTDIR)/compileplugin.so: $(3)
+$(CLANGOUTDIR)/compileplugin.so: CLANGOBJS += $(3)
+endef
+
+$(foreach src, $(CLANGSRC), $(eval $(call clangbuildsrc,$(src),$(CLANGINDIR)/$(src),$(CLANGOUTDIR)/$(src:.cxx=.o))))
+
+$(CLANGOUTDIR)/compileplugin.so: $(CLANGOBJS)
+	$(CXX) -shared $(CLANGOBJS) -o $@
+
+# vim: set noet sw=4 ts=4: