Double quote prepended when exporting CMAKE compile option using zephyr_get_compile_options_for_lang()

[kurddt]

Describe the bug
A extra and unwanted '"' is prepended when using the output of zephyr_get_compile_options_for_lang() to set an other target compile option. This lead to a compilation failure (gcc does not really like this extra double quote)

example:

/usr/bin/arm-none-eabi-gcc -DLZG_SAVED_WINDOWS=1 -O3 -funroll-loops -W -Wall -Wno-extra " -O2 -imacros /home/glager/node/mcu/TN2/bluid/zephyr/include/generated/autoconf.h -ffreestanding -fno-common -g -mcpu=cortex-m4 -mthumb -mabi=aapcs -mfpu=fpv4-sp-d16 -mfloat-abi=hard -imacros /home/glager/node/mcu/zephyr/include/toolchain/zephyr_stdint.h -Wall -Wformat -Wformat-security -Wno-format-zero-length -Wno-main -Wno-pointer-sign -Wpointer-arith -Wno-unused-but-set-variable -Werror=implicit-int -fno-asynchronous-unwind-tables -fno-pie -fno-pic -fno-strict-overflow -ffunction-sections -Wformat=0 -Wno-format-security -fno-reorder-functions -fno-defer-pop -fstack-usage -ffunction-sections -fdata-sections -specs=nano.specs -std=c99" -MD -MT liblzg/src/lib/CMakeFiles/lzg.dir/checksum.c.obj -MF liblzg/src/lib/CMakeFiles/lzg.dir/checksum.c.obj.d -o liblzg/src/lib/CMakeFiles/lzg.dir/checksum.c.obj -c /home/glager/node/mcu/tremornet.tools/liblzg/src/lib/checksum.c

instead of

/usr/bin/arm-none-eabi-gcc -DLZG_SAVED_WINDOWS=1 -O3 -funroll-loops -W -Wall -Wno-extra -O2 -imacros /home/glager/node/mcu/TN2/bluid/zephyr/include/generated/autoconf.h -ffreestanding -fno-common -g -mcpu=cortex-m4 -mthumb -mabi=aapcs -mfpu=fpv4-sp-d16 -mfloat-abi=hard -imacros /home/glager/node/mcu/zephyr/include/toolchain/zephyr_stdint.h -Wall -Wformat -Wformat-security -Wno-format-zero-length -Wno-main -Wno-pointer-sign -Wpointer-arith -Wno-unused-but-set-variable -Werror=implicit-int -fno-asynchronous-unwind-tables -fno-pie -fno-pic -fno-strict-overflow -ffunction-sections -Wformat=0 -Wno-format-security -fno-reorder-functions -fno-defer-pop -fstack-usage -ffunction-sections -fdata-sections -specs=nano.specs -std=c99 -MD -MT liblzg/src/lib/CMakeFiles/lzg.dir/checksum.c.obj -MF liblzg/src/lib/CMakeFiles/lzg.dir/checksum.c.obj.d -o liblzg/src/lib/CMakeFiles/lzg.dir/checksum.c.obj -c /home/glager/node/mcu/tremornet.tools/liblzg/src/lib/checksum.c

To Reproduce

• Have a zephyr-independant target (here lzg) and do:

zephyr_get_system_include_directories_for_lang(C ext_system_includes)
zephyr_get_compile_definitions_for_lang(C ext_definitions)

zephyr_get_compile_options_for_lang(C ext_options)

target_compile_options(lzg PRIVATE ${ext_options})
target_include_directories(lzg PRIVATE ${ext_system_includes})

Only zephyr_get_compile_options_for_lang seems to add this extra double quote, zephyr_get_system_include_directories_for_lang does not

Expected behavior
The extra double quote should not be added

Impact
This is kind of a show stopper since I can't compile my application anymore

Environment (please complete the following information):

• OS: Linux
• GNU Arm Embedded toolchain
• Zephyr-v2.4.0

[tejlmand]

The zephyr_get_compile_options_for_lang(C ext_options) was originally intended to be used integration to external build system/libraries, such as here:

zephyr/samples/application_development/external_lib/CMakeLists.txt

Line 55 in 49fdfd4

CFLAGS=${external_project_cflags}

but it does have a side-effect, and that is that it is process order dependent (you may not get flags added after this code was called).
I have done some cleanup and improvements, but need to keep the code working for main use case.
A safer approach in your case is to do:

target_compile_options(lzg PRIVATE $<TARGET_PROPERTY:zephyr_interface,INTERFACE_COMPILE_OPTIONS>)
target_include_directories(lzg SYSTEM PRIVATE $<TARGET_PROPERTY:zephyr_interface,INTERFACE_SYSTEM_INCLUDE_DIRECTORIES>)

also look at openthread for inspiration:
https://github.com/zephyrproject-rtos/openthread/blob/zephyr/zephyr/CMakeLists.txt#L214-L229

btw. your code snippet doesn't use: ext_definitions

[kurddt]

Ok, thanks for the tip. This is working perfectly