Figure out how to abuse MSYS2 repositories

In the end, all seems to work fairly well on Windows 10.

CMakeLists.txt

@@ -348,12 +348,16 @@ if (WIN32)
 		DESTINATION etc)
 	install (DIRECTORY
 		${WIN32_DEPENDS_PATH}/lib/gdk-pixbuf-2.0
-		DESTINATION lib)
+		DESTINATION lib
+		FILES_MATCHING PATTERN "*" PATTERN "*.a" EXCLUDE)
 	install (DIRECTORY
 		${WIN32_DEPENDS_PATH}/share/glib-2.0/schemas
 		DESTINATION share/glib-2.0
 		FILES_MATCHING PATTERN "org.gtk.Settings.*")
 
+	install (DIRECTORY
+		${WIN32_DEPENDS_PATH}/share/icons/Adwaita
+		DESTINATION share/icons OPTIONAL)
 	install (FILES
 		${WIN32_DEPENDS_PATH}/share/icons/hicolor/index.theme
 		DESTINATION share/icons/hicolor)

README.adoc

@@ -51,7 +51,7 @@ After _cpack_ finishes making the package, install this file.
 
 Build from source on Windows
 ----------------------------
-_Note that with the current method we're stuck with GTK+ 3.10.4 at best._
+_Note that with the current method we're stuck with GTK+ 3.8.2._
 
 First install CMake >= 3.1 and MinGW. Add both to your system path. If you want
 to build an installation package, also install NSIS.
@@ -86,7 +86,6 @@ By default, that is if you specify no generator, both packages are built.
 
 Cross-compilation for Windows
 -----------------------------
-
 The procedure is almost exactly the same as before, including the requirements.
 Just install MinGW-w64 and let automation take care of the rest.
 
@@ -94,7 +93,17 @@ Just install MinGW-w64 and let automation take care of the rest.
  $ mkdir build
  $ cd build
  $ cmake .. \
-   -DCMAKE_TOOLCHAIN_FILE=../ToolchainDebianMinGWW64.cmake \
+   -DCMAKE_TOOLCHAIN_FILE=../ToolchainCrossMinGWW64.cmake \
+   -DCMAKE_BUILD_TYPE=Release
+ $ cpack
+
+Alternatively, for an unnecessarily bloated MSYS2-based 64-bit build:
+
+ $ sh Win64Depends.cmake
+ $ mkdir build
+ $ cd build
+ $ cmake .. \
+   -DCMAKE_TOOLCHAIN_FILE=../ToolchainCrossWin64.cmake \
    -DCMAKE_BUILD_TYPE=Release
  $ cpack
 

ToolchainCrossWin64.cmake

@@ -0,0 +1,16 @@
+set (CMAKE_SYSTEM_NAME "Windows")
+set (CMAKE_SYSTEM_PROCESSOR "x86_64")
+
+set (CMAKE_C_COMPILER "x86_64-w64-mingw32-gcc")
+set (CMAKE_CXX_COMPILER "x86_64-w64-mingw32-g++")
+set (CMAKE_RC_COMPILER "x86_64-w64-mingw32-windres")
+
+# Not needed to crosscompile an installation package
+#set (CMAKE_CROSSCOMPILING_EMULATOR "wine")
+
+set (CMAKE_FIND_ROOT_PATH "/usr/x86_64-w64-mingw32")
+
+set (CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set (CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set (CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+

Win64Depends.sh

@@ -0,0 +1,69 @@
+#!/bin/sh -e
+# Win64Depends.sh: download dependencies from MSYS2 for cross-compilation
+# Dependencies: AWK, sed, cURL, bsdtar, wine64
+repository=https://repo.msys2.org/mingw/mingw64/
+
+status() {
+	echo "$(tput bold)-- $*$(tput sgr0)"
+}
+
+# TODO: Try to verify checksums, it will be relatively low-effort.
+dbsync() {
+	status Fetching repository DB
+	[ -f db.tsv ] || curl -# "$repository/mingw64.db" | bsdtar -xOf- | awk '
+		function flush() { print f["%NAME%"] f["%FILENAME%"] f["%DEPENDS%"] }
+		NR > 1 && $0 == "%FILENAME%" { flush(); for (i in f) delete f[i] }
+		{ if (/^[^%]/) f[field] = f[field] $0 "\t"; else field = $0 }
+		END { flush() }
+	' > db.tsv
+}
+
+fetch() {
+	status Resolving "$@"
+	mkdir -p packages
+	awk -F'\t' 'function get(name,    i, a) {
+		if (visited[name]++ || !(name in filenames)) return
+		print filenames[name]
+		split(deps[name], a)
+		for (i in a) get(a[i])
+	} BEGIN { while ((getline < "db.tsv") > 0) {
+		filenames[$1] = $2; deps[$1] = ""
+		for (i = 3; i <= NF; i++) { gsub(/[<=>].*/, "", $i)
+			deps[$1] = deps[$1] $i FS }
+	} for (i = 0; i < ARGC; i++) get(ARGV[i]) }' "$@" | while IFS= read -r name
+	do
+		status Fetching "$name"
+		[ -f "packages/$name" ] || curl -#o "packages/$name" "$repository/$name"
+	done
+}
+
+extract() {
+	status Extracting packages
+	for subdir in *
+	do [ -d "$subdir" -a "$subdir" != packages ] && rm -rf -- "$subdir"
+	done
+	for i in packages/*
+	do bsdtar -xf "$i" --strip-components 1 mingw64
+	done
+}
+
+configure() {
+	status Configuring packages
+	glib-compile-schemas share/glib-2.0/schemas
+	wine64 bin/gdk-pixbuf-query-loaders.exe \
+		> lib/gdk-pixbuf-2.0/2.10.0/loaders.cache
+
+	# pkgconf has a command line option for this, but CMake can't pass it
+	sed -i "s|^prefix=/mingw64|prefix=$(pwd)|" lib/pkgconfig/*.pc
+}
+
+mkdir -p win32-depends
+cd win32-depends
+dbsync
+fetch mingw-w64-x86_64-gtk3 mingw-w64-x86_64-lua \
+	mingw-w64-x86_64-libwinpthread-git # because we don't do "provides"?
+extract
+configure
+
+# XXX: Why is this override needed to run some GLib-based things under wine64?
+export XDG_DATA_DIRS=$(pwd)/share