Fix format specifier for printing CAN message ID in CanMsg.h. #198

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Merged

aentinger merged 1 commit into arduino:master from haydenroche5:mbed_can_msg_fix

Sep 4, 2023

Merged

Fix format specifier for printing CAN message ID in CanMsg.h. #198

aentinger merged 1 commit into arduino:master from haydenroche5:mbed_can_msg_fix

Sep 4, 2023

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@haydenroche5 haydenroche5 commented Aug 25, 2023

Reproducible with an empty sketch:

// my_example.ino
void setup()
{
}
void loop()
{
}

Compiled with:

arduino-cli compile --build-property compiler.cpp.extra_flags='-Wno-unused-parameter -Werror' --fqbn arduino:mbed_nano:nano33ble --log-level trace --verbose --warnings all my_example/my_example.ino

Tail of the output:

In file included from /home/hroche/.arduino15/packages/arduino/hardware/mbed_nano/4.0.4/cores/arduino/api/CanMsgRingbuffer.h:17:0,
 from /home/hroche/.arduino15/packages/arduino/hardware/mbed_nano/4.0.4/cores/arduino/api/CanMsgRingbuffer.cpp:12:
/home/hroche/.arduino15/packages/arduino/hardware/mbed_nano/4.0.4/cores/arduino/api/CanMsg.h: In member function 'virtual size_t arduino::CanMsg::printTo(arduino::Print&) const':
/home/hroche/.arduino15/packages/arduino/hardware/mbed_nano/4.0.4/cores/arduino/api/CanMsg.h:71:71: error: format '%X' expects argument of type 'unsigned int', but argument 4 has type 'uint32_t {aka long unsigned int}' [-Werror=format=]
 len = snprintf(buf, sizeof(buf), "[%08X] (%d) : ", id, data_length);
 ~~ ^
cc1plus: all warnings being treated as errors
Used platform Version Path 
arduino:mbed_nano 4.0.4 /home/hroche/.arduino15/packages/arduino/hardware/mbed_nano/4.0.4
Error during build: exit status

@haydenroche5


 Fix format specifier for printing CAN message ID in CanMsg.h.

a5b8e43

Regarding the X format specifier: C standard §7.21.6.1: "The unsigned int
argument is converted to ..." On some platforms (e.g. mbed_nano), uint32_t,
which is what's being printed here, is an unsigned long int, so this code causes
a compiler warning. The fix is to use the format specifiers from §7.8.1,
specifically PRIX32.