zephyrproject-rtos · carlescufi · Oct 22, 2021 · Mar 22, 2021 · Oct 15, 2021 · Oct 15, 2021
diff --git a/Kconfig.zephyr b/Kconfig.zephyr
@@ -507,6 +507,20 @@ config MAKEFILE_EXPORTS
  third party Makefile-based build systems.
 
 endmenu
+
+config EXPERIMENTAL
+ bool
+ help
+ Symbol that must be selected by a feature if it is considered to be
+ at an experimental implementation stage.
+
+config WARN_EXPERIMENTAL
+ bool
+ prompt "Warn on experimental usage"
+ help
+ Print a warning when the Kconfig tree is parsed if any experimental
+ features are enabled.
+
 endmenu
 
 

diff --git a/doc/application/index.rst b/doc/application/index.rst
@@ -605,6 +605,28 @@ The other pages in the :ref:`Kconfig section of the manual <kconfig>` are also
 worth going through, especially if you planning to add new configuration
 options.
 
+Experimental features
+*********************
+
+Zephyr is a project under constant development and thus there are features that
+are still in early stages of their development cycle. Such features will be
+marked ``[EXPERIMENTAL]`` in their Kconfig title.
+
+The :kconfig:`CONFIG_WARN_EXPERIMENTAL` setting can be used to enable warnings
+at CMake configure time if any experimental feature is enabled.
+
+.. code-block:: none
+
+ CONFIG_WARN_EXPERIMENTAL=y
+
+For example, enabling experimental warnings and building a sample which enables
+:kconfig:`CONFIG_BT_EXT_ADV` will print the following warning at CMake
+configure time.
+
+.. code-block:: shell
+
+ warning: Experimental symbol BT_EXT_ADV is enabled.
+
 Devicetree Overlays
 ===================
 

@@ -25,6 +25,7 @@ config BT_H5
  bool "H:5 UART [EXPERIMENTAL]"
  select UART_INTERRUPT_DRIVEN
  select BT_UART
+ select EXPERIMENTAL
  depends on SERIAL
  help
  Bluetooth three-wire (H:5) UART driver. Implementation of HCI

diff --git a/drivers/can/Kconfig.net b/drivers/can/Kconfig.net
@@ -5,6 +5,7 @@
 
 config CAN_NET
  bool "Enable 6loCAN network interface [EXPERIMENTAL]"
+ select EXPERIMENTAL
  help
  Enable IPv6 Networking over can (6loCAN)
 

diff --git a/scripts/kconfig/kconfig.py b/scripts/kconfig/kconfig.py
@@ -17,7 +17,7 @@
 # Zephyr doesn't use tristate symbols. They're supported here just to make the
 # script a bit more generic.
 from kconfiglib import Kconfig, split_expr, expr_value, expr_str, BOOL, \
- TRISTATE, TRI_TO_STR, AND
+ TRISTATE, TRI_TO_STR, AND, OR
 
 
 def main():
@@ -62,6 +62,9 @@ def main():
  check_assigned_sym_values(kconf)
  check_assigned_choice_values(kconf)
 
+ if kconf.syms['WARN_EXPERIMENTAL'].tri_value == 2:
+ check_experimental(kconf)
+
  # Hack: Force all symbols to be evaluated, to catch warnings generated
  # during evaluation. Wait till the end to write the actual output files, so
  # that we don't generate any output if there are warnings-turned-errors.
@@ -202,6 +205,17 @@ def check_assigned_choice_values(kconf):
 """
 
 
+def check_experimental(kconf):
+ experimental = kconf.syms['EXPERIMENTAL']
+ dep_expr = experimental.rev_dep
+
+ if dep_expr is not kconf.n:
+ selectors = [s for s in split_expr(dep_expr, OR) if expr_value(s) == 2]
+ for selector in selectors:
+ selector_name = split_expr(selector, AND)[0].name
+ warn(f'Experimental symbol {selector_name} is enabled.')
+
+
 def promptless(sym):
  # Returns True if 'sym' has no prompt. Since the symbol might be defined in
  # multiple locations, we need to check all locations.

diff --git a/subsys/bluetooth/Kconfig.adv b/subsys/bluetooth/Kconfig.adv
@@ -16,6 +16,7 @@ config BT_LIM_ADV_TIMEOUT
 
 config BT_EXT_ADV
  bool "Extended Advertising and Scanning support [EXPERIMENTAL]"
+ select EXPERIMENTAL
  help
  Select this to enable Extended Advertising API support.
  This enables support for advertising with multiple advertising sets,
@@ -45,6 +46,7 @@ config BT_EXT_ADV_MAX_ADV_SET
 
 config BT_PER_ADV
  bool "Periodic Advertising and Scanning support [EXPERIMENTAL]"
+ select EXPERIMENTAL
  help
  Select this to enable Periodic Advertising API support. This allows
  the device to send advertising data periodically at deterministic
@@ -54,6 +56,7 @@ config BT_PER_ADV
 config BT_PER_ADV_SYNC
  bool "Periodic advertising sync support [EXPERIMENTAL]"
  depends on BT_OBSERVER
+ select EXPERIMENTAL
  help
  Select this to enable Periodic Advertising Sync API support.
  Syncing with a periodic advertiser allows the device to periodically

diff --git a/subsys/bluetooth/Kconfig.iso b/subsys/bluetooth/Kconfig.iso
@@ -12,6 +12,7 @@ config BT_ISO_UNICAST
  bool "Bluetooth Isochronous Channel Unicast Support [EXPERIMENTAL]"
  depends on BT_CONN
  select BT_ISO
+ select EXPERIMENTAL
  help
  This option enables support for Bluetooth Broadcast
  Isochronous channels.
@@ -34,6 +35,7 @@ config BT_ISO_SYNC_RECEIVER
  select BT_ISO_BROADCAST
  select BT_OBSERVER
  select BT_PER_ADV_SYNC
+ select EXPERIMENTAL
  help
  This option enables support for the Bluetooth Isochronous
  Synchronized Receiver.

diff --git a/subsys/bluetooth/audio/Kconfig b/subsys/bluetooth/audio/Kconfig
@@ -7,7 +7,8 @@
 #
 
 menuconfig BT_AUDIO
- bool "Bluetooth Audio support [Experimental]"
+ bool "Bluetooth Audio support [EXPERIMENTAL]"
+ select EXPERIMENTAL
  help
  This option enables Bluetooth Audio support. The specific
  features that are available may depend on other features

diff --git a/subsys/bluetooth/controller/Kconfig b/subsys/bluetooth/controller/Kconfig
@@ -454,6 +454,7 @@ config BT_CTLR_ADV_EXT
 
 config BT_CTLR_ADV_EXT
  prompt "LE Advertising Extensions [EXPERIMENTAL]" if BT_LL_SW_SPLIT
+ select EXPERIMENTAL if BT_LL_SW_SPLIT
 
 if BT_CTLR_ADV_EXT
 
@@ -490,6 +491,7 @@ config BT_CTLR_ADV_PERIODIC
 
 config BT_CTLR_ADV_PERIODIC
  bool "LE Periodic Advertising in Advertising State [EXPERIMENTAL]" if BT_LL_SW_SPLIT
+ select EXPERIMENTAL if BT_LL_SW_SPLIT
 
 config BT_CTLR_SYNC_PERIODIC
  bool "LE Periodic Advertising in Synchronization State" if !BT_LL_SW_SPLIT
@@ -502,6 +504,7 @@ config BT_CTLR_SYNC_PERIODIC
 
 config BT_CTLR_SYNC_PERIODIC
  bool "LE Periodic Advertising in Synchronization State [EXPERIMENTAL]" if BT_LL_SW_SPLIT
+ select EXPERIMENTAL if BT_LL_SW_SPLIT
 
 config BT_CTLR_SYNC_PERIODIC_ADV_LIST
  bool "LE Periodic Advertiser List support"
@@ -538,6 +541,7 @@ config BT_CTLR_ADV_ISO
 
 config BT_CTLR_ADV_ISO
  bool "LE Broadcast Isochronous Channel advertising [EXPERIMENTAL]" if BT_LL_SW_SPLIT
+ select EXPERIMENTAL if BT_LL_SW_SPLIT
 
 config BT_CTLR_SYNC_ISO
  bool "LE Broadcast Isochronous Channel advertising sync" if !BT_LL_SW_SPLIT
@@ -550,6 +554,7 @@ config BT_CTLR_SYNC_ISO
 
 config BT_CTLR_SYNC_ISO
  bool "LE Broadcast Isochronous Channel advertising sync [EXPERIMENTAL]" if BT_LL_SW_SPLIT
+ select EXPERIMENTAL if BT_LL_SW_SPLIT
 
 config BT_CTLR_BROADCAST_ISO
  bool
@@ -584,6 +589,7 @@ endif # BT_CTLR_ADV_EXT
 
 config BT_CTLR_SET_HOST_FEATURE
  bool "LE Set Host Feature Command [EXPERIMENTAL]"
+ select EXPERIMENTAL
  help
  Enables optional LE Set Host Feature Command
 
@@ -597,6 +603,7 @@ config BT_CTLR_CENTRAL_ISO
 config BT_CTLR_CENTRAL_ISO
  bool "LE Connected Isochronous Stream Central [EXPERIMENTAL]" if BT_LL_SW_SPLIT
  select BT_CTLR_SET_HOST_FEATURE
+ select EXPERIMENTAL if BT_LL_SW_SPLIT
 
 config BT_CTLR_PERIPHERAL_ISO
  bool "LE Connected Isochronous Stream Peripheral" if !BT_LL_SW_SPLIT
@@ -608,6 +615,7 @@ config BT_CTLR_PERIPHERAL_ISO
 config BT_CTLR_PERIPHERAL_ISO
  bool "LE Connected Isochronous Stream Peripheral [EXPERIMENTAL]" if BT_LL_SW_SPLIT
  select BT_CTLR_SET_HOST_FEATURE
+ select EXPERIMENTAL if BT_LL_SW_SPLIT
 
 config BT_CTLR_CONN_ISO
  bool

diff --git a/subsys/bluetooth/controller/Kconfig.df b/subsys/bluetooth/controller/Kconfig.df
@@ -30,8 +30,9 @@ config BT_CTLR_CTEINLINE_SUPPORT
  bool
 
 menuconfig BT_CTLR_DF
- bool "LE Direction Finding [Experimental]"
+ bool "LE Direction Finding [EXPERIMENTAL]"
  depends on BT_CTLR_DF_SUPPORT
+ select EXPERIMENTAL
  help
  Enable support for Bluetooth 5.1 Direction Finding
 

diff --git a/subsys/bluetooth/host/Kconfig b/subsys/bluetooth/host/Kconfig
@@ -551,6 +551,7 @@ config BT_ID_MAX
 
 config BT_DF
  bool "Enable Direction Finding support [EXPERIMENTAL]"
+ select EXPERIMENTAL
  help
  Enable support for Bluetooth 5.1 Direction Finding.
  It will allow to: get information about antennae, configure
@@ -752,6 +753,7 @@ config BT_BREDR
  select BT_CENTRAL
  select BT_SMP
  select BT_L2CAP_DYNAMIC_CHANNEL
+ select EXPERIMENTAL
  help
  This option enables Bluetooth BR/EDR support
 
@@ -766,6 +768,7 @@ config BT_MAX_SCO_CONN
 
 config BT_RFCOMM
  bool "Bluetooth RFCOMM protocol support [EXPERIMENTAL]"
+ select EXPERIMENTAL
  help
  This option enables Bluetooth RFCOMM support
 
@@ -782,17 +785,20 @@ config BT_HFP_HF
  bool "Bluetooth Handsfree profile HF Role support [EXPERIMENTAL]"
  depends on PRINTK
  select BT_RFCOMM
+ select EXPERIMENTAL
  help
  This option enables Bluetooth HF support
 
 config BT_AVDTP
  bool "Bluetooth AVDTP protocol support [EXPERIMENTAL]"
+ select EXPERIMENTAL
  help
  This option enables Bluetooth AVDTP support
 
 config BT_A2DP
  bool "Bluetooth A2DP Profile [EXPERIMENTAL]"
  select BT_AVDTP
+ select EXPERIMENTAL
  help
  This option enables the A2DP profile
 

diff --git a/subsys/bluetooth/host/Kconfig.gatt b/subsys/bluetooth/host/Kconfig.gatt
@@ -27,6 +27,7 @@ config BT_ATT_PREPARE_COUNT
 config BT_EATT
  bool "Enhanced ATT Bearers support [EXPERIMENTAL]"
  depends on BT_L2CAP_ECRED
+ select EXPERIMENTAL
  help
  This option enables support for Enhanced ATT bearers support. When
  enabled additional L2CAP channels can be connected as bearers enabling

diff --git a/subsys/bluetooth/mesh/Kconfig b/subsys/bluetooth/mesh/Kconfig
@@ -69,6 +69,7 @@ config BT_MESH_PROVISIONER
 config BT_MESH_CDB
  bool "Mesh Configuration Database [EXPERIMENTAL]"
  default y if BT_MESH_PROVISIONER
+ select EXPERIMENTAL
 
 if BT_MESH_CDB
 

diff --git a/subsys/bluetooth/services/ots/Kconfig b/subsys/bluetooth/services/ots/Kconfig
@@ -8,6 +8,7 @@ config BT_OTS
  select BT_L2CAP_DYNAMIC_CHANNEL
  select BT_GATT_DYNAMIC_DB
  select BT_SMP
+ select EXPERIMENTAL
  help
  Enable Object Transfer Service.
 

diff --git a/subsys/canbus/isotp/Kconfig b/subsys/canbus/isotp/Kconfig
@@ -7,6 +7,7 @@ menuconfig ISOTP
  bool "ISO-TP Transport [EXPERIMENTAL]"
  select NET_BUF
  select POLL
+ select EXPERIMENTAL
  help
  Enable ISO TP support for CAN
 

diff --git a/subsys/net/l2/canbus/Kconfig b/subsys/net/l2/canbus/Kconfig
@@ -5,6 +5,7 @@ config NET_L2_CANBUS
  bool "Enable CANBUS L2 layer [EXPERIMENTAL]"
  depends on CAN_NET
  select NET_6LO
+ select EXPERIMENTAL
  help
  Add a CANBUS L2 layer driver. This is the layer for IPv6 over CAN
  (6loCAN). It uses IPHC to compress the IP header and ISO-TP for