[retro-plugins] Add atari-2600 plugin

[Adrien Plazas <aplazas src gnome org>]

commit 6837a5165d9457aab26718a71ac1a738645d9c2c
Author: Ricard Gascons <gascons1995 gmail com>
Date:   Tue Mar 22 19:39:16 2016 +0100

    Add atari-2600 plugin
    
    Wrap stella-libretro as the atari-2600 plugin.

 .gitmodules                        |    3 +++
 configure.ac                       |    1 +
 plugins/Makefile.am                |    4 ++++
 plugins/atari-2600/Makefile.in     |   12 ++++++++++++
 plugins/atari-2600/configure.ac    |   20 ++++++++++++++++++++
 plugins/atari-2600/stella-libretro |    1 +
 6 files changed, 41 insertions(+), 0 deletions(-)
---
diff --git a/.gitmodules b/.gitmodules
index 3a1e08d..8cb86d7 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -16,3 +16,6 @@
 [submodule "plugins/neo-geo-pocket/beetle-ngp-libretro"]
        path = plugins/neo-geo-pocket/beetle-ngp-libretro
        url = https://github.com/libretro/beetle-ngp-libretro.git
+[submodule "plugins/atari-2600/stella-libretro"]
+       path = plugins/atari-2600/stella-libretro
+       url = https://github.com/libretro/stella-libretro.git
diff --git a/configure.ac b/configure.ac
index 7058cff..de66ee9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -6,6 +6,7 @@ AC_PROG_CC
 LT_INIT
 
 # Plugins
+m4_include([plugins/atari-2600/configure.ac])
 m4_include([plugins/game-boy/configure.ac])
 m4_include([plugins/mame/configure.ac])
 m4_include([plugins/neo-geo-pocket/configure.ac])
diff --git a/plugins/Makefile.am b/plugins/Makefile.am
index ab54c5e..e4a858c 100644
--- a/plugins/Makefile.am
+++ b/plugins/Makefile.am
@@ -1,5 +1,9 @@
 SUBDIRS =
 
+if ENABLE_ATARI_2600_PLUGIN
+SUBDIRS += atari-2600
+endif
+
 if ENABLE_GAME_BOY_PLUGIN
 SUBDIRS += game-boy
 endif
diff --git a/plugins/atari-2600/Makefile.in b/plugins/atari-2600/Makefile.in
new file mode 100644
index 0000000..567ed1b
--- /dev/null
+++ b/plugins/atari-2600/Makefile.in
@@ -0,0 +1,12 @@
+SYSTEM_NAME = atari-2600
+SUBMODULE_DIR = stella-libretro
+
+OUT = $(srcdir)/$(SUBMODULE_DIR)/stella_libretro.so
+
+-include ../submodule-plugin.mk
+
+$(OUT):
+       make -C $(srcdir)/$(SUBMODULE_DIR)
+
+submodule-clean:
+       make -C $(srcdir)/$(SUBMODULE_DIR) clean
\ No newline at end of file
diff --git a/plugins/atari-2600/configure.ac b/plugins/atari-2600/configure.ac
new file mode 100644
index 0000000..62d9837
--- /dev/null
+++ b/plugins/atari-2600/configure.ac
@@ -0,0 +1,20 @@
+# When there are no modules to check, default to 'no', hence we need to
+# force it to 'yes'.
+#PKG_CHECK_MODULES(ATARI_2600_PLUGIN, [
+#], [enable_atari_2600_plugin=yes], [enable_atari_2600_plugin=no])
+enable_atari_2600_plugin=yes
+
+# Checks for programs.
+AC_PROG_CXX
+AC_PROG_CC
+AC_PROG_CPP
+AC_PROG_INSTALL
+AC_PROG_LN_S
+AC_PROG_MAKE_SET
+
+
+AM_CONDITIONAL(ENABLE_ATARI_2600_PLUGIN, test x$enable_atari_2600_plugin != xno)
+
+AC_CONFIG_FILES([
+       plugins/atari-2600/Makefile
+])
\ No newline at end of file
diff --git a/plugins/atari-2600/stella-libretro b/plugins/atari-2600/stella-libretro
new file mode 160000
index 0000000..7b62cff
--- /dev/null
+++ b/plugins/atari-2600/stella-libretro
@@ -0,0 +1 @@
+Subproject commit 7b62cff4d070ff51668c3c434a33c3b2d7c3e7d0