DevHeads IoT Integration Server•6mo ago

When compiling my FreeRTOS, my functions in string.c conflict with the built-in function 'tolower'

Hey guys When compiling my FreeRTOS, my functions in string.c conflict with the built-in function 'tolower'. Can I use a CFLAGS to resolve this error, and how can i do it? Here's my code

makefile
all: my_rtos

my_rtos: main.o string.o
    gcc -o my_rtos main.o string.o
    
main.o: main.c
    gcc -c main.c

string.o: string.c
    gcc -c -Dmy_tolower=custom_tolower string.c

makefile
all: my_rtos

my_rtos: main.o string.o
    gcc -o my_rtos main.o string.o
    
main.o: main.c
    gcc -c main.c

string.o: string.c
    gcc -c -Dmy_tolower=custom_tolower string.c

@Middleware & OS

2 Replies

Enthernet Code•6mo ago

Your code is accurate and should work as intended, but just in case, here's an improved version

#include <stdio.h>

void swapBytes(uint8_t *array, size_t length)
{
    // Check if the array is NULL
    if (array == NULL)
    {
        printf("Array pointer is NULL.\n");
        return;
    }

    // Ensure the length is a multiple of 4
    if (length % 4 != 0)
    {
        printf("Array length must be a multiple of 4.\n");
        return;
    }

    for (size_t i = 0; i < length; i += 4)
    {
        // Swap the bytes within each group of 4
        uint8_t temp0 = array[i];
        uint8_t temp1 = array[i + 1];
        uint8_t temp2 = array[i + 2];
        uint8_t temp3 = array[i + 3];

        array[i] = temp3;
        array[i + 1] = temp2;
        array[i + 2] = temp1;
        array[i + 3] = temp0;
    }
}

#include <stdio.h>

void swapBytes(uint8_t *array, size_t length)
{
    // Check if the array is NULL
    if (array == NULL)
    {
        printf("Array pointer is NULL.\n");
        return;
    }

    // Ensure the length is a multiple of 4
    if (length % 4 != 0)
    {
        printf("Array length must be a multiple of 4.\n");
        return;
    }

    for (size_t i = 0; i < length; i += 4)
    {
        // Swap the bytes within each group of 4
        uint8_t temp0 = array[i];
        uint8_t temp1 = array[i + 1];
        uint8_t temp2 = array[i + 2];
        uint8_t temp3 = array[i + 3];

        array[i] = temp3;
        array[i + 1] = temp2;
        array[i + 2] = temp1;
        array[i + 3] = temp0;
    }
}

Boss lady•6mo ago

Yes you can use CFLAGS, it should look like this 👇

CFLAGS += -Dmy_tolower=custom_tolower

all: my_rtos

my_rtos: main.o string.o
    gcc $(CFLAGS) -o my_rtos main.o string.o
    
main.o: main.c
    gcc $(CFLAGS) -c main.c

string.o: string.c
    gcc $(CFLAGS) -c string.c

CFLAGS += -Dmy_tolower=custom_tolower

all: my_rtos

my_rtos: main.o string.o
    gcc $(CFLAGS) -o my_rtos main.o string.o
    
main.o: main.c
    gcc $(CFLAGS) -c main.c

string.o: string.c
    gcc $(CFLAGS) -c string.c

Gaming

Programming

When compiling my FreeRTOS, my functions in string.c conflict with the built-in function 'tolower'