From 2630fbaa75f3e6a412134949eae3d4d183d4c9b1 Mon Sep 17 00:00:00 2001
From: Kumar Gala <kumar.gala@linaro.org>
Date: Fri, 24 Jan 2020 09:39:40 -0600
Subject: [PATCH] cmake: Introduce optional Kconfig for toolchains
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Allow a given toolchain to specify Kconfig options that might be
relevant to a feature available in that toolchain.

For example, the ARM embedded GNU toolchain supports two variants of
newlib and you select the smaller one via a spec file.  We can use a
Kconfig option like HAS_NEWLIB_LIBC_NANO to convey that this feature is
supported by that toolchain.

We look for the toolchain Kconfig in ${TOOLCHAIN_KCONFIG_DIR}/Kconfig,
and default TOOLCHAIN_KCONFIG_DIR to:

${TOOLCHAIN_ROOT}/cmake/toolchain/${ZEPHYR_TOOLCHAIN_VARIANT})

toolchain specific cmake files can override the default if needed.

Additionally tweaked the zephyr/generic.cmake to use
${CMAKE_CURRENT_LIST_DIR} to reduce some duplication.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
---
 Kconfig.zephyr                       | 1 +
 cmake/generic_toolchain.cmake        | 2 ++
 cmake/kconfig.cmake                  | 2 ++
 cmake/toolchain/gnuarmemb/Kconfig    | 7 +++++++
 cmake/toolchain/zephyr/0.11/Kconfig  | 7 +++++++
 cmake/toolchain/zephyr/generic.cmake | 4 +++-
 6 files changed, 22 insertions(+), 1 deletion(-)
 create mode 100644 cmake/toolchain/gnuarmemb/Kconfig
 create mode 100644 cmake/toolchain/zephyr/0.11/Kconfig

diff --git a/Kconfig.zephyr b/Kconfig.zephyr
index 7f39ff2a5bc..6d067ec47bc 100644
--- a/Kconfig.zephyr
+++ b/Kconfig.zephyr
@@ -45,6 +45,7 @@ source "subsys/Kconfig"
 
 source "ext/Kconfig"
 
+osource "$(TOOLCHAIN_KCONFIG_DIR)/Kconfig"
 
 menu "Build and Link Features"
 
diff --git a/cmake/generic_toolchain.cmake b/cmake/generic_toolchain.cmake
index c579ea76dc1..bd9fcdd55a9 100644
--- a/cmake/generic_toolchain.cmake
+++ b/cmake/generic_toolchain.cmake
@@ -63,6 +63,8 @@ endif()
 # Configure the toolchain based on what SDK/toolchain is in use.
 include(${TOOLCHAIN_ROOT}/cmake/toolchain/${ZEPHYR_TOOLCHAIN_VARIANT}/generic.cmake)
 
+set_ifndef(TOOLCHAIN_KCONFIG_DIR ${TOOLCHAIN_ROOT}/cmake/toolchain/${ZEPHYR_TOOLCHAIN_VARIANT})
+
 # Configure the toolchain based on what toolchain technology is used
 # (gcc, host-gcc etc.)
 include(${TOOLCHAIN_ROOT}/cmake/compiler/${COMPILER}/generic.cmake OPTIONAL)
diff --git a/cmake/kconfig.cmake b/cmake/kconfig.cmake
index c1753fbc3b8..9dc8342dc70 100644
--- a/cmake/kconfig.cmake
+++ b/cmake/kconfig.cmake
@@ -48,6 +48,7 @@ set(ENV{ARCH_DIR}   ${ARCH_DIR})
 set(ENV{DEVICETREE_CONF} ${DEVICETREE_CONF})
 set(ENV{DTS_POST_CPP} ${DTS_POST_CPP})
 set(ENV{DTS_ROOT_BINDINGS} "${DTS_ROOT_BINDINGS}")
+set(ENV{TOOLCHAIN_KCONFIG_DIR} "${TOOLCHAIN_KCONFIG_DIR}")
 
 # Allow out-of-tree users to add their own Kconfig python frontend
 # targets by appending targets to the CMake list
@@ -90,6 +91,7 @@ foreach(kconfig_target
     SHIELD_AS_LIST=$ENV{SHIELD_AS_LIST}
     CMAKE_BINARY_DIR=$ENV{CMAKE_BINARY_DIR}
     ZEPHYR_TOOLCHAIN_VARIANT=${ZEPHYR_TOOLCHAIN_VARIANT}
+    TOOLCHAIN_KCONFIG_DIR=${TOOLCHAIN_KCONFIG_DIR}
     ARCH_DIR=$ENV{ARCH_DIR}
     DEVICETREE_CONF=${DEVICETREE_CONF}
     DTS_POST_CPP=${DTS_POST_CPP}
diff --git a/cmake/toolchain/gnuarmemb/Kconfig b/cmake/toolchain/gnuarmemb/Kconfig
new file mode 100644
index 00000000000..42e08668829
--- /dev/null
+++ b/cmake/toolchain/gnuarmemb/Kconfig
@@ -0,0 +1,7 @@
+# GNU ARM Embedded Toolchain
+
+# Copyright (c) 2020 Linaro Limited.
+# SPDX-License-Identifier: Apache-2.0
+
+config TOOLCHAIN_GNUARMEMB
+	def_bool y
diff --git a/cmake/toolchain/zephyr/0.11/Kconfig b/cmake/toolchain/zephyr/0.11/Kconfig
new file mode 100644
index 00000000000..3a3d8b62680
--- /dev/null
+++ b/cmake/toolchain/zephyr/0.11/Kconfig
@@ -0,0 +1,7 @@
+# Zephyr 0.11 SDK Toolchain
+
+# Copyright (c) 2020 Linaro Limited.
+# SPDX-License-Identifier: Apache-2.0
+
+config TOOLCHAIN_ZEPHYR_0_11
+	def_bool y
diff --git a/cmake/toolchain/zephyr/generic.cmake b/cmake/toolchain/zephyr/generic.cmake
index e1bb2894404..be0622201ca 100644
--- a/cmake/toolchain/zephyr/generic.cmake
+++ b/cmake/toolchain/zephyr/generic.cmake
@@ -4,4 +4,6 @@ if (NOT ZEPHYR_SDK_INSTALL_DIR)
   message(FATAL_ERROR "ZEPHYR_SDK_INSTALL_DIR must be set")
 endif()
 
-include(${ZEPHYR_BASE}/cmake/toolchain/zephyr/${SDK_MAJOR_MINOR}/generic.cmake)
+include(${CMAKE_CURRENT_LIST_DIR}/${SDK_MAJOR_MINOR}/generic.cmake)
+
+set(TOOLCHAIN_KCONFIG_DIR ${CMAKE_CURRENT_LIST_DIR}/${SDK_MAJOR_MINOR})