Missing `stdlib.h` include when C++ standard library is used.

[simonmarti]

Describe the bug

stdlib.h is not in the GCC search path when the C++ standard library is used.

To Reproduce

prj.conf:

CONFIG_NEWLIB_LIBC=y
CONFIG_CPLUSPLUS=y

main.cpp:

#include <zephyr.h>
#include <misc/printk.h>
#include <array>


void main(void)
{
	std::array<int, 3> a{ 1, 2, 3 };

	for (const auto x: a)
	{
		printk("x: %d", x);
	}
}

Steps to reproduce the behavior:

1. mkdir build && cd build
2. cmake -GNinja -DBOARD=arduino_zero ..
3. ninja
4. Build fails because of missing include, see console output below

Expected behavior

The example code above should compile.

Impact

I can not use the C++ standard library for my current project.

Screenshots or console output

> ninja
[15/101] Building CXX object CMakeFiles/app.dir/src/main.cpp.obj
FAILED: CMakeFiles/app.dir/src/main.cpp.obj 
C:\Users\username\tools\gcc-arm-none-eabi-7-2018-q2-update-win32\bin\arm-none-eabi-g++.exe  -DBUILD_VERSION=zephyr-v1.14.0 -DKERNEL -D_FORTIFY_SOURCE=2 -D__LINUX_ERRNO_EXTENSIONS__ -D__ZEPHYR__=1 -IC:/Users/username/zephyrproject/zephyr/kernel/include -IC:/Users/username/zephyrproject/zephyr/arch/arm/include -IC:/Users/username/zephyrproject/zephyr/include -IC:/Users/username/zephyrproject/zephyr/include/drivers -Izephyr/include/generated -IC:/Users/username/zephyrproject/zephyr/soc/arm/atmel_sam0/samd21 -IC:/Users/username/zephyrproject/zephyr/ext/hal/atmel/asf/sam0/include/samd21 -IC:/Users/username/zephyrproject/zephyr/ext/hal/cmsis/Include -isystem C:/Users/username/tools/gcc-arm-none-eabi-7-2018-q2-update-win32/arm-none-eabi/include -std=c++11 -Os -fcheck-new -Wno-register -fno-exceptions -fno-rtti -g -Wall -Wformat -Wformat-security -Wno-format-zero-length -imacros C:/Users/username/tmp/hello_world/build/zephyr/include/generated/autoconf.h -ffreestanding -Wno-main -fno-common -mthumb -mcpu=cortex-m0plus -fno-asynchronous-unwind-tables -fno-pie -fno-pic -fno-strict-overflow -Wno-unused-but-set-variable -fno-reorder-functions -fno-defer-pop -Werror=implicit-int -Wpointer-arith -ffunction-sections -fdata-sections -mabi=aapcs -march=armv6s-m -MD -MT CMakeFiles/app.dir/src/main.cpp.obj -MF CMakeFiles\app.dir\src\main.cpp.obj.d -o CMakeFiles/app.dir/src/main.cpp.obj -c ../src/main.cpp
In file included from c:\users\username\tools\gcc-arm-none-eabi-7-2018-q2-update-win32\arm-none-eabi\include\c++\7.3.1\ext\string_conversions.h:41:0,
                 from c:\users\username\tools\gcc-arm-none-eabi-7-2018-q2-update-win32\arm-none-eabi\include\c++\7.3.1\bits\basic_string.h:6352,
                 from c:\users\username\tools\gcc-arm-none-eabi-7-2018-q2-update-win32\arm-none-eabi\include\c++\7.3.1\string:52,
                 from c:\users\username\tools\gcc-arm-none-eabi-7-2018-q2-update-win32\arm-none-eabi\include\c++\7.3.1\stdexcept:39,
                 from c:\users\username\tools\gcc-arm-none-eabi-7-2018-q2-update-win32\arm-none-eabi\include\c++\7.3.1\array:39,
                 from ../src/main.cpp:8:
c:\users\username\tools\gcc-arm-none-eabi-7-2018-q2-update-win32\arm-none-eabi\include\c++\7.3.1\cstdlib:75:15: fatal error: stdlib.h: No such file or directory
 #include_next <stdlib.h>
               ^~~~~~~~~~
compilation terminated.
[28/101] Building C object zephyr/CMakeFiles/zephyr.dir/lib/os/printk.c.obj
ninja: build stopped: subcommand failed..

Environment (please complete the following information):

• OS: Windows 10 1903
• Toolchain: GNU ARM Embedded 7-2018-q2-update
• Zephyr: v1.14.0

Additional context

This might be related to issue #15603. I tried the suggested workaround, but it does not help.

I tried several Zephyr versions:

• v1.14.1-rc1
• v1.14.99 (latest master, commit 1c6952c )
• v1.14.0-rc1

v1.14.0-rc1 works but in this version the shell is not C++ compatible yet, so there are other problems to work around.

I also tried the latest GNU ARM Embedded toolchain (8-2019-q3-update), but also no success here.

If you can point my in the right direction, I will happily provide a fix myself.

[carlescufi]

@simonmarti could you please try with the Zephyr SDK instead of GNU Arm Embedded and let us know if you can reproduce the same issue?

EDIT: I tried and the SDK doesn't seem to be able to find <array>:

FAILED: CMakeFiles/app.dir/src/main.c.obj
/home/carles/bin/zephyr-sdk/arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc -DBUILD_VERSION=zephyr-v1.14.0-2394-g474c99c9ef7f -DKERNEL -DNRF52840_XXAA -D_FORTIFY_SOURCE=2 -D__LINUX_ERRNO_EXTENSIONS__ -D__ZEPHYR__=1 -I/home/carles/src/zephyr/zephyr/kernel/include -I/home/carles/src/zephyr/zephyr/arch/arm/include -I/home/carles/src/zephyr/zephyr/include -I/home/carles/src/zephyr/zephyr/include/drivers -Izephyr/include/generated -I/home/carles/src/zephyr/zephyr/soc/arm/nordic_nrf/nrf52 -I/home/carles/src/zephyr/zephyr/soc/arm/nordic_nrf/include -I/home/carles/src/zephyr/zephyr/ext/hal/cmsis/Include -I/home/carles/src/zephyr/zephyr/ext/hal/nordic/nrfx -I/home/carles/src/zephyr/zephyr/ext/hal/nordic/nrfx/drivers/include -I/home/carles/src/zephyr/zephyr/ext/hal/nordic/nrfx/hal -I/home/carles/src/zephyr/zephyr/ext/hal/nordic/nrfx/mdk -I/home/carles/src/zephyr/zephyr/ext/hal/nordic/. -isystem /home/carles/bin/zephyr-sdk/arm-zephyr-eabi/arm-zephyr-eabi/include -Os -imacros/home/carles/src/zephyr/zephyr/samples/hello_world/build/hello_world/nrf52840_pca10056/zephyr/include/generated/autoconf.h -ffreestanding -fno-common -g -mthumb -mcpu=cortex-m4 -imacros/home/carles/src/zephyr/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 -fno-reorder-functions -fno-defer-pop -fmacro-prefix-map=/home/carles/src/zephyr/zephyr/samples/hello_world=CMAKE_SOURCE_DIR -fmacro-prefix-map=/home/carles/src/zephyr/zephyr=ZEPHYR_BASE -ffunction-sections -fdata-sections -mabi=aapcs -march=armv7e-m -std=c99 -MD -MT CMakeFiles/app.dir/src/main.c.obj -MF CMakeFiles/app.dir/src/main.c.obj.d -o CMakeFiles/app.dir/src/main.c.obj   -c ../../../src/main.c
../../../src/main.c:4:10: fatal error: array: No such file or directory
 #include <array>
          ^~~~~~~
compilation terminated.

[pabigot]

I'm unable to reproduce this with zephyr-1.14.0 and ZEPHYR_TOOLCHAIN_VARIANT=zephyr resolves to SDK 0.10.0. <array> is found and correct output is written. SDK 0.10.1 is unsupported in zephyr-1.14.0. It also works with current head of v1.14-branch.

I can confirm the problem as reported is present when ZEPHYR_TOOLCHAIN_VARIANT=gnuarmemb and current v1.14-branch.

@carlescufi it appears you're using a C source filemain.c instead of a C++ file main.cc, which would explain the failure to find <array>.

[carlescufi]

I'm unable to reproduce this with zephyr-1.14.0 and ZEPHYR_TOOLCHAIN_VARIANT=zephyr resolves to SDK 0.10.0. <array> is found and correct output is written. SDK 0.10.1 is unsupported in zephyr-1.14.0. It also works with current head of v1.14-branch.

I can confirm the problem as reported is present when ZEPHYR_TOOLCHAIN_VARIANT=gnuarmemb and current v1.14-branch.

@carlescufi it appears you're using a C source filemain.c instead of a C++ file main.cc, which would explain the failure to find <array>.

Thanks @pabigot. I can confirm the same in master. There is clearly an issue with GNU Arm Embedded and newlib/C++. @galak or @SebastianBoe is that something you could take a look at?

[cszawisza]

I think that I've got the same error couple of months ago... this solved the issue

diff --git a/lib/libc/newlib/CMakeLists.txt b/lib/libc/newlib/CMakeLists.txt
index d368d1b89a8e1097eb7fda43044772c52738aba5..71061aa905131dbf85ead6dd0b56fb863e570b84 100644
--- a/lib/libc/newlib/CMakeLists.txt
+++ b/lib/libc/newlib/CMakeLists.txt
@@ -14,7 +14,7 @@ zephyr_library_sources(libc-hooks.c)
 # our libc headers to be picked instead of the toolchain's ffreestanding
 # headers.
 if(LIBC_INCLUDE_DIR)
-  zephyr_system_include_directories(${LIBC_INCLUDE_DIR})
+  zephyr_include_directories(${LIBC_INCLUDE_DIR})
 endif()
 
 if(LIBC_LIBRARY_DIR)

Can somebody confirm?

[pabigot]

I can confirm that the problem goes away by making newlib headers not system headers, but given 7d2df83 was just merged I'm not convinced it's the right solution. Presumably Zephyr and ARM do something different in builds that affects how system include files are handed.

[SebastianBoe]

Hi, I have proposed a solution to the related issue #15603 here: #18189

The PR is intended to also fix this issue (17564), but I've not been able to reproduce all the reports here, so I'm not certain that it does so. Reports that show that #18189 does not fix #17564 for all environments would be welcome.

[simonmarti]

@cszawisza Thanks, the change fixes the problem for my environment.

@SebastianBoe I tested the change proposed in #18189 with my environment, but it does not solve the issue. The error message is still the same.

The environment I used for the test:

• OS: Windows 10 1903
• Toolchain: GNU ARM Embedded 7-2018-q2-update / 8-2019-q3-update
• Zephyr: v2.0.0-rc1