python,python3: define config option for bluetooth support

It was reported via
https://github.com/openwrt/packages/pull/5122#issuecomment-347395472
that if bluez-libs is selected as an installable package,
then the error below will show up:
```
 * satisfy_dependencies_for: Cannot satisfy the following dependencies for python-light:
 *	bluez-libs *
 * opkg_install_cmd: Cannot install package python-light.
```

This looks like a limitation in the design of package deps,
and maybe a misuse of conditional deps (i.e. PACKAGE_bluez-libs:bluez-libs).

So, to fix this, an idea we're adding an extra symbol
that enfoces installation of bluez-libs if selected.

We also need to add a way to disable bluetooth build
if PYTHON(3)_BLUETOOTH_SUPPORT is de-selected.
Otherwise, bluetooth is installed and the socket
module is broken due to linker errors.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

lang/python/python/Config-python-light.in

@@ -0,0 +1,7 @@
+menu "Configuration"
+
+config PYTHON_BLUETOOTH_SUPPORT
+	bool "Enable Bluetooth support"
+	default n
+
+endmenu

lang/python/python/Makefile

@@ -14,7 +14,7 @@ PKG_NAME:=python
 PKG_VERSION:=$(PYTHON_VERSION).$(PYTHON_VERSION_MICRO)
 # XXX: reset PKG_RELEASE to 1 only if Python's pip & setuptools versions have also bumped;
 #      otherwise, keep bumping PKG_RELEASE
-PKG_RELEASE:=4
+PKG_RELEASE:=5
 
 PKG_SOURCE:=Python-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=https://www.python.org/ftp/python/$(PKG_VERSION)
@@ -39,9 +39,9 @@ HOST_BUILD_DIR:=$(BUILD_DIR_HOST)/Python-$(PKG_VERSION)
 
 PKG_CONFIG_DEPENDS:= \
 	CONFIG_PACKAGE_python-setuptools CONFIG_PACKAGE_python-pip \
-	CONFIG_PACKAGE_bluez-libs
+	CONFIG_PYTHON_BLUETOOTH_SUPPORT
 
-PKG_BUILD_DEPENDS:=python/host PACKAGE_bluez-libs:bluez-libs
+PKG_BUILD_DEPENDS:=python/host
 HOST_BUILD_DEPENDS:=bzip2/host expat/host
 
 include $(INCLUDE_DIR)/host-build.mk
@@ -79,7 +79,11 @@ endef
 define Package/python-light
 $(call Package/python/Default)
   TITLE:=Python $(PYTHON_VERSION) light installation
-  DEPENDS:=+python-base +libffi +libbz2 +PACKAGE_bluez-libs:bluez-libs
+  DEPENDS:=+python-base +libffi +libbz2 +PYTHON_BLUETOOTH_SUPPORT:bluez-libs
+endef
+
+define Package/python-light/config
+  source "$(SOURCE)/Config-python-light.in"
 endef
 
 define Package/python-light/description
@@ -140,6 +144,10 @@ PYTHON_FOR_BUILD:= \
 	_PYTHON_SYSCONFIGDATA_NAME=_sysconfigdata \
 	$(HOST_PYTHON_BIN)
 
+DISABLE_BLUETOOTH:= \
+    ac_cv_header_bluetooth_bluetooth_h=no \
+    ac_cv_header_bluetooth_h=no
+
 CONFIGURE_ARGS+= \
 	--sysconfdir=/etc \
 	--enable-shared \
@@ -148,6 +156,7 @@ CONFIGURE_ARGS+= \
 	--with-system-ffi \
 	--with-ensurepip=no \
 	--without-pymalloc \
+	$(if $(CONFIG_PYTHON_BLUETOOTH_SUPPORT),,$(DISABLE_BLUETOOTH)) \
 	PYTHON_FOR_BUILD="$(PYTHON_FOR_BUILD)" \
 	$(ENABLE_IPV6) \
 	CONFIG_SITE="$(PKG_BUILD_DIR)/config.site" \

lang/python/python3/Config-python3-light.in

@@ -0,0 +1,7 @@
+menu "Configuration"
+
+config PYTHON3_BLUETOOTH_SUPPORT
+	bool "Enable Bluetooth support"
+	default n
+
+endmenu

lang/python/python3/Makefile

@@ -16,7 +16,7 @@ PYTHON_VERSION_MICRO:=$(PYTHON3_VERSION_MICRO)
 PKG_NAME:=python3
 # XXX: reset PKG_RELEASE to 1 only if Python's pip & setuptools versions have also bumped;
 #      otherwise, keep bumping PKG_RELEASE
-PKG_RELEASE:=10
+PKG_RELEASE:=11
 PKG_VERSION:=$(PYTHON_VERSION).$(PYTHON_VERSION_MICRO)
 
 PKG_SOURCE:=Python-$(PKG_VERSION).tar.xz
@@ -42,10 +42,9 @@ HOST_BUILD_DIR:=$(BUILD_DIR_HOST)/Python-$(PKG_VERSION)
 
 PKG_CONFIG_DEPENDS:= \
 	CONFIG_PACKAGE_python3-setuptools CONFIG_PACKAGE_python3-pip \
-	CONFIG_PACKAGE_bluez-libs
+	CONFIG_PYTHON3_BLUETOOTH_SUPPORT
 
-
-PKG_BUILD_DEPENDS:=python3/host PACKAGE_bluez-libs:bluez-libs
+PKG_BUILD_DEPENDS:=python3/host
 HOST_BUILD_DEPENDS:=bzip2/host expat/host libffi/host
 
 include $(INCLUDE_DIR)/host-build.mk
@@ -83,7 +82,11 @@ endef
 define Package/python3-light
 $(call Package/python3/Default)
   TITLE:=Python $(PYTHON_VERSION) light installation
-  DEPENDS:=+python3-base +libffi +libbz2 +PACKAGE_bluez-libs:bluez-libs
+  DEPENDS:=+python3-base +libffi +libbz2 +PYTHON3_BLUETOOTH_SUPPORT:bluez-libs
+endef
+
+define Package/python3-light/config
+  source "$(SOURCE)/Config-python3-light.in"
 endef
 
 define Package/python3-light/description
@@ -145,6 +148,10 @@ PYTHON_FOR_BUILD:= \
 	_PYTHON_SYSCONFIGDATA_NAME=_sysconfigdata \
 	$(HOST_PYTHON3_BIN)
 
+DISABLE_BLUETOOTH:= \
+	ac_cv_header_bluetooth_bluetooth_h=no \
+	ac_cv_header_bluetooth_h=no
+
 CONFIGURE_ARGS+= \
 	--sysconfdir=/etc \
 	--enable-shared \
@@ -153,6 +160,7 @@ CONFIGURE_ARGS+= \
 	--with-system-ffi \
 	--with-ensurepip=no \
 	--without-pymalloc \
+	$(if $(CONFIG_PYTHON3_BLUETOOTH_SUPPORT),,$(DISABLE_BLUETOOTH)) \
 	PYTHON_FOR_BUILD="$(PYTHON_FOR_BUILD)" \
 	$(ENABLE_IPV6) \
 	CONFIG_SITE="$(PKG_BUILD_DIR)/config.site" \