testing/libc/wcstombs: Add testing application for wcstombs

[tmedicci]

Summary

• testing/libc/wcstombs: Add testing application for wcstombs

This application tests the libc's wcstombs function for different len sizes (bigger than the converted string, exactly the size of it and smaller than it).

Impact

Enabling testing the libc's wcstombs()function. No impact on existing applications. This application is used to test a bugfix regarding wcstombs behavior.

Testing

Internal CI testing + rv-virt:nsh:

Build with:

make -j distclean && ./tools/configure.sh rv-virt:nsh && kconfig-tweak -e LIBC_LOCALE && kconfig-tweak -e TESTING_WCSTOMBS && make olddefconfig && make

Run with:

$ qemu-system-riscv32 -semihosting -M virt,aclint=on -cpu rv32 -smp 1 -bios none -kernel nuttx -nographic
ABC
NuttShell (NSH) NuttX-10.4.0
nsh> help
help usage:  help [-v] [<cmd>]

    .           cmp         false       mount       set         uptime      
    [           dirname     fdinfo      mv          sleep       usleep      
    ?           dd          free        pidof       source      watch       
    alias       df          help        poweroff    test        xd          
    unalias     dmesg       hexdump     quit        time        wait        
    basename    echo        kill        printf      true        
    break       env         pkill       ps          truncate    
    cat         exec        ls          pwd         uname       
    cd          exit        mkdir       rm          umount      
    cp          expr        mkrd        rmdir       unset       

Builtin Apps:
    getprime    hello       nsh         ostest      sh          wcstombs    
nsh> wcstombs
wcstombs Test application:

Test Scenario: len is bigger than the size of the converted string. Expected the null-terminator at the end of the converted string.
Return code: 13
dst buffer (as uint8_t array): 48 65 6c 6c 6f 2c 20 77 6f 72 6c 64 21 aa 
The character just after the return value is not the expected null-terminator (value: aa). This is a bug!
nsh> QEMU: Terminated

[cederom]

Thank you @tmedicci :-)