fully support out of tree builds

* You no longer have to copy contrib/scintilla, contrib/scinterm and contrib/lexilla
  manually to the build directory.
* It turns out, that Scintilla/Lexilla was supporting this since 2016.
  Scintilla allows pointing to a source directory (srdir) and Lexilla to a binary directory (DIR_O).
* For Scinterm I opened a pull request in order to add srcdir/basedir variables:
  https://github.com/orbitalquark/scinterm/pull/21
* `make distcheck` is therefore now also fixed.
* The FreeBSD package is now allowed to build out of source.
  I haven't tested it yet.
* See also https://github.com/ScintillaOrg/lexilla/issues/266

1 files changed, 39 insertions, 26 deletions

diff --git a/contrib/scintilla.am b/contrib/scintilla.am
index 55511b0..9ba728b 100644
--- a/contrib/scintilla.am
+++ b/contrib/scintilla.am
@@ -1,33 +1,32 @@
 # We use the existing Scintilla/Lexilla Makefile build system to
 # avoid redundancies and maintainance overhead.
 # These build systems produce static libraries (*.a).
-# This however has two diadvantages:
-# 1.) Out-of-tree builds are not straight forward and require
-#     manually cloning the submodules into the build system.
-#     `make distcheck` is consequently also broken.
-#     Lexilla already has DIR_O, that could be used for proper
-#     out of tree builds, but Scintilla is still lacking it.
-# 2.) We cannot add plain static libraries to libtool convenience
-#     libraries using LIBADD.
-#     Therefore, we cannot wrap Scintilla and Lexilla into a convenience
-#     library.
-#     That's why this file must instead be included everywhere where
-#     scintilla.a and liblexilla.a are referenced and they must be added
-#     to programs using LDADD.
+# This however has the following disadvantages:
+#
+# * We cannot add plain static libraries to libtool convenience
+#   libraries using LIBADD.
+#   Therefore, we cannot wrap Scintilla and Lexilla into a convenience
+#   library.
+#   That's why this file must instead be included everywhere where
+#   scintilla.a and liblexilla.a are referenced and they must be added
+#   to programs using LDADD.
+
+LIBSCINTILLA = @abs_top_builddir@/contrib/scintilla/bin/scintilla.a
 
 if INTERFACE_GTK
-MAKE_SCINTILLA = $(MAKE) -C @SCINTILLA_PATH@/gtk \
+MAKE_SCINTILLA = $(MAKE) -C @top_builddir@/contrib/scintilla/bin \
+                 -f @SCINTILLA_PATH@/gtk/makefile \
+                 srcdir=@SCINTILLA_PATH@/gtk \
+                 COMPLIB=$(LIBSCINTILLA) \
                  GTK3=yes CONFIGFLAGS='@LIBGTK_CFLAGS@' \
                  CXXFLAGS='@SCINTILLA_CXXFLAGS@'
 else
-# NOTE: The VPATH hack allows us to keep Scinterm separate from
-# the Scintilla repo and avoid using recursive submodules.
-#
-# FIXME: There is currently no way to override the standard optimization
-# flags of Scinterm, so we pass them in CURSES_FLAGS.
-MAKE_SCINTILLA = $(MAKE) -C @SCINTILLA_PATH@/bin -f @SCINTERM_PATH@/Makefile \
-                 VPATH=@SCINTERM_PATH@ \
-                 CURSES_FLAGS='@PDCURSES_CFLAGS@ @XCURSES_CFLAGS@ @NCURSES_CFLAGS@ @SCINTILLA_CXXFLAGS@'
+MAKE_SCINTILLA = $(MAKE) -C @top_builddir@/contrib/scintilla/bin \
+                 -f @SCINTERM_PATH@/Makefile \
+                 srcdir=@SCINTERM_PATH@ basedir=@SCINTILLA_PATH@ \
+                 scintilla=$(LIBSCINTILLA) \
+                 CXXFLAGS='@SCINTILLA_CXXFLAGS@' \
+                 CURSES_FLAGS='@PDCURSES_CFLAGS@ @XCURSES_CFLAGS@ @NCURSES_CFLAGS@'
 endif
 
 # Pass toolchain configuration to Scintilla.
@@ -40,21 +39,33 @@ MAKE_SCINTILLA += CC='@CC@' CXX='@CXX@' \
 # If it's up to date, the additional recursive
 # make call does not hurt.
 .PHONY: make-scintilla
+# FIXME: deps.mak cannot be generated when building out-of-tree.
+# Also this would draw in a Python dependency.
+# It needs to be removed in clean-local-scintilla to appease `make distcheck`.
 make-scintilla:
-	$(MAKE_SCINTILLA) ../bin/scintilla.a
+	mkdir -p @top_builddir@/contrib/scintilla/bin
+	touch @top_builddir@/contrib/scintilla/bin/deps.mak
+	$(MAKE_SCINTILLA) $(LIBSCINTILLA)
 
 # scintilla.a itself is not phony.
 # This avoids unnecessary relinking if it is
 # up to date.
 # Also note the ; which defines this recipe as
 # empty.
-@SCINTILLA_PATH@/bin/scintilla.a : make-scintilla;
+$(LIBSCINTILLA) : make-scintilla;
 
 .PHONY: clean-local-scintilla
 clean-local-scintilla:
+	mkdir -p @top_builddir@/contrib/scintilla/bin
 	$(MAKE_SCINTILLA) clean
+	test "@abs_top_srcdir" = "@abs_top_builddir@" || \
+		$(RM) -f @top_builddir@/contrib/scintilla/bin/deps.mak
+
+LIBLEXILLA = @abs_top_builddir@/contrib/lexilla/bin/liblexilla.a
 
 MAKE_LEXILLA = $(MAKE) -C @LEXILLA_PATH@/src \
+               DIR_O=@abs_top_builddir@/contrib/lexilla/bin \
+               DIR_BIN=@abs_top_builddir@/contrib/lexilla/bin \
                SCINTILLA_INCLUDE=@SCINTILLA_PATH@/include \
                CXXFLAGS='@SCINTILLA_CXXFLAGS@' \
                CC='@CC@' CXX='@CXX@' \
@@ -68,12 +79,14 @@ MAKE_LEXILLA += BASE_FLAGS=''
 
 .PHONY: make-lexilla
 make-lexilla:
-	$(MAKE_LEXILLA) ../bin/liblexilla.a
+	mkdir -p @top_builddir@/contrib/lexilla/bin
+	$(MAKE_LEXILLA) $(LIBLEXILLA)
 
-@LEXILLA_PATH@/bin/liblexilla.a : make-lexilla;
+$(LIBLEXILLA) : make-lexilla;
 
 .PHONY: clean-local-lexilla
 clean-local-lexilla:
+	mkdir -p @top_builddir@/contrib/lexilla/bin
 	$(MAKE_LEXILLA) clean
 
 # NOTE: using a separate `clean-local-scintilla`