warnings when using newlibc and threads

[bpbradley]

Describe the bug
I noticed after going from 2.6 to the latest 2.7 release candidate, I was getting a number of warnings about type conversions that were unrelated to my application. They appear to be related to use of CONFIG_NEWLIB_LIBC

To Reproduce
Steps to reproduce the behavior:

1. Build samples/basic/threads with CONFIG_NEWLIB_LIBC=y
2. Observe warnings

Expected behavior
Clean build without warning with or without CONFIG_NEWLIB_LIBC=y

Environment (please complete the following information):

• OS: (Windows)
• Toolchain (gnuarmemb)
• zephyr version: 11dd83b

[stephanosio]

I am unable to reproduce this (though, it was on Linux).

Please post a more detailed bug report that includes essential information such as:

1. The actual warning messages
2. The board you are building
3. The version of the GNU Arm Embedded toolchain you are using

[bpbradley]

Ah sure, sorry I forgot to mention that.

The board was nrf52840dk_nrf52840. Here is the output when building.

PS C:\Users\bbradley\Documents\git\Firmware\zephyr\fp-workspace> west build -b nrf52840dk_nrf52840 -s .\rtos\zephyr\samples\basic\threads\
-- west build: generating a build system
Including boilerplate (Zephyr base): C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/cmake/app/boilerplate.cmake
-- Application: C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/samples/basic/threads
-- Zephyr version: 2.7.99 (C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr), build: v2.7.99-498-g11dd83b02b3c
-- Found Python3: C:/Users/bbradley/.pyenv/pyenv-win/versions/3.8.2/python.exe (found suitable exact version "3.8.2") found components: Interpreter 
-- Found west (found suitable version "0.11.0", minimum required is "0.7.1")
-- Board: nrf52840dk_nrf52840
-- Cache files will be written to: C:\Users\bbradley\AppData\Local/.cache/zephyr
-- Found dtc: C:/ProgramData/chocolatey/bin/dtc.exe (found suitable version "1.4.7", minimum required is "1.4.6")
-- Found toolchain: gnuarmemb (C:/gnuarmemb)
-- Found BOARD.dts: C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/boards/arm/nrf52840dk_nrf52840/nrf52840dk_nrf52840.dts
-- Generated zephyr.dts: C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/build/zephyr/zephyr.dts
-- Generated devicetree_unfixed.h: C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/build/zephyr/include/generated/devicetree_unfixed.h
-- Generated device_extern.h: C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/build/zephyr/include/generated/device_extern.h
-- Including generated dts.cmake file: C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/build/zephyr/dts.cmake
Parsing C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/Kconfig
Loaded configuration 'C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/boards/arm/nrf52840dk_nrf52840/nrf52840dk_nrf52840_defconfig'
Merged configuration 'C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/samples/basic/threads/prj.conf'
Configuration saved to 'C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/build/zephyr/.config'
Kconfig header saved to 'C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/build/zephyr/include/generated/autoconf.h'
-- The C compiler identification is GNU 7.3.1
-- The CXX compiler identification is GNU 7.3.1
-- The ASM compiler identification is GNU
-- Found assembler: C:/gnuarmemb/bin/arm-none-eabi-gcc.exe
CMake Warning at C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/CMakeLists.txt:1649 (message):
  __ASSERT() statements are globally ENABLED


-- Configuring done
-- Generating done
-- Build files have been written to: C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/build
-- west build: building application
[26/135] Building C object zephyr/lib/libc/newlib/CMakeFiles/lib__libc__newlib.dir/libc-hooks.c.obj
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c: In function '__retarget_lock_init':
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:358:8: warning: assignment makes integer from pointer without a cast [-Wint-conversion]      
  *lock = malloc(sizeof(struct k_sem));
        ^
In file included from c:\users\bbradley\documents\git\firmware\zephyr\fp-workspace\rtos\zephyr\modules\hal_nordic\nrfx\nrfx_glue.h:10:0,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/modules/hal/nordic/nrfx/nrfx.h:39,
                 from c:\users\bbradley\documents\git\firmware\zephyr\fp-workspace\rtos\zephyr\soc\arm\nordic_nrf\soc_nrf_common.h:14,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/soc/arm/nordic_nrf/nrf52/soc.h:14,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/cortex_m/cmsis.h:17,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/mpu/arm_mpu_v7m.h:11,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/mpu/arm_mpu.h:14,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/arch.h:187,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/cpu.h:19,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:7:
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:362:17: warning: comparison between pointer and integer
  __ASSERT(*lock != NULL, "non-recursive lock allocation failed");
                 ^
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/sys/__assert.h:94:9: note: in definition of macro '__ASSERT'
   if (!(test)) {                                            \
         ^~~~
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c: In function '__retarget_lock_init_recursive':
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:374:8: warning: assignment makes integer from pointer without a cast [-Wint-conversion]      
  *lock = malloc(sizeof(struct k_mutex));
        ^
In file included from c:\users\bbradley\documents\git\firmware\zephyr\fp-workspace\rtos\zephyr\modules\hal_nordic\nrfx\nrfx_glue.h:10:0,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/modules/hal/nordic/nrfx/nrfx.h:39,
                 from c:\users\bbradley\documents\git\firmware\zephyr\fp-workspace\rtos\zephyr\soc\arm\nordic_nrf\soc_nrf_common.h:14,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/soc/arm/nordic_nrf/nrf52/soc.h:14,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/cortex_m/cmsis.h:17,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/mpu/arm_mpu_v7m.h:11,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/mpu/arm_mpu.h:14,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/arch.h:187,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/cpu.h:19,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:7:
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:378:17: warning: comparison between pointer and integer
  __ASSERT(*lock != NULL, "recursive lock allocation failed");
                 ^
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/sys/__assert.h:94:9: note: in definition of macro '__ASSERT'
   if (!(test)) {                                            \
         ^~~~
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c: In function '__retarget_lock_close':
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:386:23: warning: comparison between pointer and integer
  __ASSERT_NO_MSG(lock != NULL);
                       ^
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/sys/__assert.h:86:9: note: in definition of macro '__ASSERT_NO_MSG'
   if (!(test)) {                                            \
         ^~~~
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:388:7: warning: passing argument 1 of 'free' makes pointer from integer without a cast [-Wint-conversion]
  free(lock);
       ^~~~
In file included from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:10:0:
c:\gnuarmemb\arm-none-eabi\include\malloc.h:45:13: note: expected 'void *' but argument is of type '_LOCK_T {aka int}'
 extern void free (void *);
             ^~~~
In file included from c:\users\bbradley\documents\git\firmware\zephyr\fp-workspace\rtos\zephyr\modules\hal_nordic\nrfx\nrfx_glue.h:10:0,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/modules/hal/nordic/nrfx/nrfx.h:39,
                 from c:\users\bbradley\documents\git\firmware\zephyr\fp-workspace\rtos\zephyr\soc\arm\nordic_nrf\soc_nrf_common.h:14,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/soc/arm/nordic_nrf/nrf52/soc.h:14,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/cortex_m/cmsis.h:17,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/mpu/arm_mpu_v7m.h:11,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/mpu/arm_mpu.h:14,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/arch.h:187,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/cpu.h:19,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:7:
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c: In function '__retarget_lock_close_recursive':
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:397:23: warning: comparison between pointer and integer
  __ASSERT_NO_MSG(lock != NULL);
                       ^
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/sys/__assert.h:86:9: note: in definition of macro '__ASSERT_NO_MSG'
   if (!(test)) {                                            \
         ^~~~
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:399:7: warning: passing argument 1 of 'free' makes pointer from integer without a cast [-Wint-conversion]
  free(lock);
       ^~~~
In file included from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:10:0:
c:\gnuarmemb\arm-none-eabi\include\malloc.h:45:13: note: expected 'void *' but argument is of type '_LOCK_T {aka int}'
 extern void free (void *);
             ^~~~
In file included from c:\users\bbradley\documents\git\firmware\zephyr\fp-workspace\rtos\zephyr\modules\hal_nordic\nrfx\nrfx_glue.h:10:0,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/modules/hal/nordic/nrfx/nrfx.h:39,
                 from c:\users\bbradley\documents\git\firmware\zephyr\fp-workspace\rtos\zephyr\soc\arm\nordic_nrf\soc_nrf_common.h:14,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/soc/arm/nordic_nrf/nrf52/soc.h:14,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/cortex_m/cmsis.h:17,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/mpu/arm_mpu_v7m.h:11,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/mpu/arm_mpu.h:14,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/arm/aarch32/arch.h:187,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/arch/cpu.h:19,
                 from C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:7:
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c: In function '__retarget_lock_acquire':
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:408:23: warning: comparison between pointer and integer
  __ASSERT_NO_MSG(lock != NULL);
                       ^
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/sys/__assert.h:86:9: note: in definition of macro '__ASSERT_NO_MSG'
   if (!(test)) {                                            \
         ^~~~
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c: In function '__retarget_lock_acquire_recursive':
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:415:23: warning: comparison between pointer and integer
  __ASSERT_NO_MSG(lock != NULL);
                       ^
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/sys/__assert.h:86:9: note: in definition of macro '__ASSERT_NO_MSG'
   if (!(test)) {                                            \
         ^~~~
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c: In function '__retarget_lock_try_acquire':
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:422:23: warning: comparison between pointer and integer
  __ASSERT_NO_MSG(lock != NULL);
                       ^
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/sys/__assert.h:86:9: note: in definition of macro '__ASSERT_NO_MSG'
   if (!(test)) {                                            \
         ^~~~
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c: In function '__retarget_lock_try_acquire_recursive':
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:429:23: warning: comparison between pointer and integer
  __ASSERT_NO_MSG(lock != NULL);
                       ^
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/sys/__assert.h:86:9: note: in definition of macro '__ASSERT_NO_MSG'
   if (!(test)) {                                            \
         ^~~~
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c: In function '__retarget_lock_release':
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:436:23: warning: comparison between pointer and integer
  __ASSERT_NO_MSG(lock != NULL);
                       ^
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/sys/__assert.h:86:9: note: in definition of macro '__ASSERT_NO_MSG'
   if (!(test)) {                                            \
         ^~~~
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c: In function '__retarget_lock_release_recursive':
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/lib/libc/newlib/libc-hooks.c:443:23: warning: comparison between pointer and integer
  __ASSERT_NO_MSG(lock != NULL);
                       ^
C:/Users/bbradley/Documents/git/Firmware/zephyr/fp-workspace/rtos/zephyr/include/sys/__assert.h:86:9: note: in definition of macro '__ASSERT_NO_MSG'
   if (!(test)) {                                            \
         ^~~~
[128/135] Linking C executable zephyr\zephyr_prebuilt.elf

[135/135] Linking C executable zephyr\zephyr.elf
Memory region         Used Size  Region Size  %age Used
           FLASH:       33972 B         1 MB      3.24%
            SRAM:        9920 B       256 KB      3.78%
        IDT_LIST:          0 GB         2 KB      0.00%
PS C:\Users\bbradley\Documents\git\Firmware\zephyr\fp-workspace>

Here is the conf file

CONFIG_PRINTK=y
CONFIG_HEAP_MEM_POOL_SIZE=256
CONFIG_ASSERT=y
CONFIG_GPIO=y
CONFIG_NEWLIB_LIBC=y

[stephanosio]

-- The C compiler identification is GNU 7.3.1
-- The CXX compiler identification is GNU 7.3.1

It looks like you are using a very old GNU Arm Embedded/GCC release that bundles an incompatible newlib version (in particular, incompatible retargetable locking interface).

Please upgrade to the latest version and you should not see these warnings. I have tested with the 10-2020-q4-major (GCC 10.2.1) release and there are no warnings.

[bpbradley]

I just noticed the same thing after you mentioned that. I have been running with this version for some time. I will update and see what I get.

Thanks!

[bpbradley]

Okay you are correct, I was just using an ancient toolchain. Thanks!