linker error using wchar.h functions MQX 4.1

[brettnicholas]

Hello,

I need to use the wchar_t data type for a C project (the project is for a K70FN1M0 on a custom PCB, running MQX 4.1 and developing in CW 10.5), but am unable to access the wchar/wstring library functions such as wprintf(), wmemcpy(), wcsncpy(), and others.

I have already made sure to #include <wchar.h> and <wstring.h>, and also selected the "Enable wchar_t support" option for ARM compiler settings in the project properties menu. I am able to use the wchar_t data type without any build errors, however I get  "Link Failed" and "wprintf() undefined" errors when I try to use any wchar functions.

Please help, thanks!

- Brett

[soledad]

Hello Brett,

This is an abstract from service request answer.

In order to add wchar support it is necessary to set the corresponding macros and they must be rebuilt. I tried setting the macros below but I got errors. Then I undo changes and rebuilt libraries as normal and tried method 2 and it worked.

_EWL_WIDE_CHAR

_EWL_WFILEIO_AVAILABLE

_EWL_OS_DISK_FILE_SUPPORT

I took fwprintf.c from its original location (C:\Freescale\CW MCU v10.6\MCU\ARM_GCC_Support\ewl\EWL_C\src\wchar) and created a copy in my project. Then in project properties (menu Project > Properties > C/C++ Build > Settings > Compiler > Preprocessor) added the macros below.

_EWL_WIDE_CHAR=1

_EWL_OS_DISK_FILE_SUPPORT=1

As there is no prototype of the function I recommend to write a prototype at the top of the file to avoid compiler confusion.

Have a great day,
Sol

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[soledad]

Hello Brett,

Please check the below thread and let me know if this helps!!

wchar.h and MQX IO incompatibility

Have a great day,
Sol

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[brettnicholas]

Hi Soledad,

Do you have any idea how I can build the EWL wchar_t libraries? I really need to get this done....I filed a support service request a week ago, but have not heard back.

[soledad]

Hello Brett,

We are working in your issue,  we will be back with an answer asap.

Regards

Sol

[brettnicholas]

Hi Soledad,

I have already read that thread, and it doesn't help. It never specifies where the __ARM_WCHAR_NO_IO macro needs to be set. I could not find it in user_config.h