gnu: retroarch: Reduce bundled libraries to a minimum.

* gnu/packages/emulators.scm (retroarch) [source]: Add snippet removing
most bundled sources.  Apply patch to allow using system SPIRV-Cross.
[phases] <configure>: Add --disable-builtinspirv_cross.  Disable non-core features making use of bundled
libraries (7zip, cheevos crtswitchres, discord, dr_mp3, ixbm, stb_font,
stb_image, stb_vorbis and xdelta).
[inputs]: Add spirv-cross.
[license]: Add licenses of bundled sources.
* gnu/packages/patches/retroarch-unbundle-spirv-cross.patch: New file.

Change-Id: I824391424bf0fa2ec3888f02535b94dea3021378

2 files changed, 141 insertions, 3 deletions

diff --git a/gnu/packages/emulators.scm b/gnu/packages/emulators.scm
index d984b7d529..35a7e845d3 100644
--- a/gnu/packages/emulators.scm
+++ b/gnu/packages/emulators.scm
@@ -1587,9 +1587,38 @@ physical device and the RetroPad virtual controller.")
        (uri (git-reference
              (url "https://github.com/libretro/RetroArch")
              (commit (string-append "v" version))))
+       (snippet
+        #~(begin
+            (use-modules (guix build utils)
+                         (ice-9 ftw)
+                         (srfi srfi-26))
+            ;; XXX: 'delete-all-but' is copied from the turbovnc package.
+            (define (delete-all-but directory . preserve)
+              (define (directory? x)
+                (and=> (stat x #f)
+                       (compose (cut eq? 'directory <>) stat:type)))
+              (with-directory-excursion directory
+                (let* ((pred
+                        (negate (cut member <> (append '("." "..") preserve))))
+                       (items (scandir "." pred)))
+                  (for-each (lambda (item)
+                              (if (directory? item)
+                                  (delete-file-recursively item)
+                                  (delete-file item)))
+                            items))))
+            ;; Remove as much bundled sources as possible, shaving off about
+            ;; 65 MiB.
+            (delete-all-but "deps"
+                            "feralgamemode" ;used in platform_unix.c
+                            "mbedtls"       ;further refined below
+                            "yxml")         ;used in rxml.c
+            ;; This is an old root certificate used in net_socket_ssl_mbed.c,
+            ;; not actually from mbedtls.
+            (delete-all-but "deps/mbedtls" "cacert.h")))
        (file-name (git-file-name name version))
        (sha256
-        (base32 "15nh4y4vpf4n1ryhiy4fwvzn5xz5idzfzn9fsi5v9hzp25vbjmrm"))))
+        (base32 "15nh4y4vpf4n1ryhiy4fwvzn5xz5idzfzn9fsi5v9hzp25vbjmrm"))
+       (patches (search-patches "retroarch-unbundle-spirv-cross.patch"))))
     (build-system gnu-build-system)
     (arguments
      (list
@@ -1626,7 +1655,20 @@ physical device and the RetroPad virtual controller.")
                "--disable-builtinbearssl"
                "--disable-builtinzlib"
                "--disable-builtinflac"
-               "--disable-builtinglslang"))))))
+               "--disable-builtinglslang"
+               "--disable-builtinspirv_cross"
+               ;; These are disabled to avoid requiring the bundled
+               ;; dependencies.
+               "--disable-7zip"
+               "--disable-cheevos"
+               "--disable-crtswitchres"
+               "--disable-discord"
+               "--disable-dr_mp3"
+               "--disable-ibxm"
+               "--disable-stb_font"
+               "--disable-stb_image"
+               "--disable-stb_vorbis"
+               "--disable-xdelta"))))))
     (inputs
      (list alsa-lib
            eudev
@@ -1648,6 +1690,7 @@ physical device and the RetroPad virtual controller.")
            python
            qtbase-5
            sdl2
+           spirv-cross
            spirv-headers
            spirv-tools
            v4l-utils
@@ -1669,7 +1712,10 @@ the easy creation of emulators, games and multimedia applications that can plug
 straight into any libretro-compatible frontend.  RetroArch is the official
 reference frontend for the libretro API, currently used by most as a modular
 multi-system game/emulator system.")
-    (license license:gpl3+)))
+    (license (list license:gpl3+         ;for RetroArch itself
+                   license:asl2.0        ;SPIRV-Cross
+                   license:expat         ;yxml
+                   license:bsd-3))))     ;feragamemode
 
 (define-public wasm4
   (package
diff --git a/gnu/packages/patches/retroarch-unbundle-spirv-cross.patch b/gnu/packages/patches/retroarch-unbundle-spirv-cross.patch
new file mode 100644
index 0000000000..dd39fab538
--- /dev/null
+++ b/gnu/packages/patches/retroarch-unbundle-spirv-cross.patch
@@ -0,0 +1,92 @@
+Upstream-status: https://github.com/libretro/RetroArch/issues/17079
+
+diff --git a/Makefile.common b/Makefile.common
+index 8ba76cf6c7..e9e8b8a643 100644
+--- a/Makefile.common
++++ b/Makefile.common
+@@ -1869,6 +1869,7 @@ endif
+ 
+ ifeq ($(HAVE_SPIRV_CROSS), 1)
+    DEFINES += -DHAVE_SPIRV_CROSS
++ifeq ($(HAVE_BUILTINSPIRV_CROSS), 1)
+    INCLUDE_DIRS += -I$(DEPS_DIR)/SPIRV-Cross
+    OBJ += $(DEPS_DIR)/SPIRV-Cross/spirv_cross.o
+    OBJ += $(DEPS_DIR)/SPIRV-Cross/spirv_cfg.o
+@@ -1877,6 +1878,13 @@ ifeq ($(HAVE_SPIRV_CROSS), 1)
+    OBJ += $(DEPS_DIR)/SPIRV-Cross/spirv_msl.o
+    OBJ += $(DEPS_DIR)/SPIRV-Cross/spirv_parser.o
+    OBJ += $(DEPS_DIR)/SPIRV-Cross/spirv_cross_parsed_ir.o
++else
++   CXXFLAGS += $(SPIRV_CROSS_CFLAGS)
++   LIBS += -lspirv-cross-core \
++           -lspirv-cross-glsl \
++           -lspirv-cross-reflect \
++           -lspirv-cross-msl
++endif
+ endif
+ 
+ ifeq ($(WANT_WGL), 1)
+diff --git a/qb/config.libs.sh b/qb/config.libs.sh
+index 2daa6b5e45..649a62690d 100644
+--- a/qb/config.libs.sh
++++ b/qb/config.libs.sh
+@@ -32,7 +32,10 @@ CLIB=-lc
+ PTHREADLIB=-lpthread
+ SOCKETLIB=-lc
+ SOCKETHEADER=
+-INCLUDES='usr/include usr/local/include'
++TR='tr'
++INCLUDES="$(echo $C_INCLUDE_PATH | $TR ':' ' ') \
++$(echo $CPLUS_INCLUDE_PATH | $TR ':' ' ') \
++usr/include usr/local/include"
+ SORT='sort'
+ EXTRA_GL_LIBS=''
+ VC_PREFIX=''
+@@ -625,6 +628,7 @@ check_enabled CXX GLSLANG glslang 'The C++ compiler is' false
+ check_enabled CXX SPIRV_CROSS SPIRV-Cross 'The C++ compiler is' false
+ 
+ check_enabled GLSLANG BUILTINGLSLANG 'builtin glslang' 'glslang is' true
++check_enabled SPIRV_CROSS BUILTINSPIRV_CROSS 'builtin spirv-cross' 'spirv-cross is' true
+ 
+ if [ "$HAVE_GLSLANG" != no ]; then
+    check_header cxx GLSLANG \
+@@ -657,6 +661,27 @@ if [ "$HAVE_GLSLANG" != no ]; then
+    fi
+ fi
+ 
++if [ "$HAVE_SPIRV_CROSS" != no ]; then
++   check_lib cxx SPIRV_CROSS -lspirv-cross-core '' '' 'spirv_cross.hpp' 'spirv_cross'
++   check_lib cxx SPIRV_CROSS_GLSL -lspirv-cross-glsl
++   check_lib cxx SPIRV_CROSS_MSL -lspirv-cross-msl
++   check_lib cxx SPIRV_CROSS_REFLECT -lspirv-cross-reflect
++   if [ "$HAVE_SPIRV_CROSS" = no ] ||
++      [ "$HAVE_SPIRV_CROSS_GLSL" = no ] ||
++      [ "$HAVE_SPIRV_CROSS_MSL" = no ] ||
++      [ "$HAVE_SPIRV_CROSS_REFLECT" = no ]; then
++      if [ "$HAVE_BUILTINSPIRV_CROSS" != yes ]; then
++         die : "Notice: System spirv-cross libraries not found, \
++disabling spirv-cross support"
++         HAVE_SPIRV_CROSS=no
++      else
++         HAVE_SPIRV_CROSS=yes
++      fi
++   else
++      HAVE_SPIRV_CROSS=yes
++   fi
++fi
++
+ if [ "$HAVE_CRTSWITCHRES" != no ]; then
+    if [ "$HAVE_CXX11" = 'no' ]; then
+       HAVE_CRTSWITCHRES=no
+diff --git a/qb/config.params.sh b/qb/config.params.sh
+index 1f1ea15637..a1653cb3cf 100644
+--- a/qb/config.params.sh
++++ b/qb/config.params.sh
+@@ -191,6 +191,7 @@ C89_GLSLANG=no
+ HAVE_BUILTINGLSLANG=auto   # Bake in glslang support
+ C89_BUILTINGLSLANG=no
+ HAVE_SPIRV_CROSS=auto      # SPIRV-Cross support (requires C++11)
++HAVE_BUILTINSPIRV_CROSS=auto    # Use bundled SPIRV-Cross source
+ C89_SPIRV_CROSS=no
+ HAVE_METAL=no              # Metal support (macOS-only)
+ C89_METAL=no