From 6331dae62394d8206c7c71088c5b42a3b7ef2d2f Mon Sep 17 00:00:00 2001
From: Danny Oerndrup <daor@demant.com>
Date: Thu, 13 Jun 2019 15:33:03 +0200
Subject: [PATCH] cmake: Toolchain abstraction: Introducing macro
 toolchain_cc_cstd_flag

The macro obtains the toolchain specific flag and value for
setting of the requested c standard.

The intent here is to abstract Zephyr's dependence on toolchains,
thus allowing for easier porting to other, perhaps commercial,
toolchains and/or usecases.

No functional change expected.

Signed-off-by: Danny Oerndrup <daor@demant.com>
---
 CMakeLists.txt                       | 4 +++-
 cmake/compiler/gcc/target_base.cmake | 6 ++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2586821ca6c..ff30fb11cdc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -984,8 +984,10 @@ get_property(GKSF GLOBAL PROPERTY GENERATED_KERNEL_SOURCE_FILES)
 get_property(CSTD GLOBAL PROPERTY CSTD)
 set_ifndef(CSTD c99)
 
+# @Intent: Obtain compiler specific flag for specifying the c standard
+toolchain_cc_cstd_flag(CC_CSTD ${CSTD})
 zephyr_compile_options(
-  $<$<COMPILE_LANGUAGE:C>:-std=${CSTD}>
+  $<$<COMPILE_LANGUAGE:C>:${CC_CSTD}>
 )
 
 # @Intent: Configure linker scripts, i.e. generate linker scripts with variables substituted
diff --git a/cmake/compiler/gcc/target_base.cmake b/cmake/compiler/gcc/target_base.cmake
index 39146c40db6..b8f834ce491 100644
--- a/cmake/compiler/gcc/target_base.cmake
+++ b/cmake/compiler/gcc/target_base.cmake
@@ -12,3 +12,9 @@ macro(toolchain_cc_nocommon)
   zephyr_compile_options(-fno-common)
 
 endmacro()
+
+macro(toolchain_cc_cstd_flag dest_var_name c_std)
+
+  set_ifndef(${dest_var_name} "-std=${c_std}")
+
+endmacro()