conflicting types for '_putchar'

[windsurfer]

Hello,

There's a problem compiling the standard ble_app_uart_pca10040_s132 in Segger Embedded Studio for ARM V3.40.  The UART example is straight out of nRF5_SDK_14.2.0_17b948a.

The exact same example can be compiled OK in SES V3.34.

The error message in V3.40 is 

conflicting types for '__putchar'

retarget.c

previous declaration of '__putchar' was here

That line points to stdio.h declaration of __puchar

[Martin Lesund]

Hi Winston,

SEGGER has added the prototype for _putchar() in stdio.h, but the declaration of this prototype has a different type of variable.

See below: 

stdio.h (line 773)

// Macro version of putchar.
#ifndef __PRINTF_TAG_PTR_DEFINED
#define __PRINTF_TAG_PTR_DEFINED
typedef struct __printf_tag *__printf_tag_ptr;
#endif
int __putchar(int, __printf_tag_ptr);
#define putchar(x) __putchar(x, 0)

 

Solution:

To solve this issue, we need to change the type of value in __putchar to __printf_tag_ptr instead of FILE *.

before: (retarget.c, line100)

int __putchar(int ch, FILE * p_file)
{
    UNUSED_PARAMETER(p_file);

    UNUSED_VARIABLE(app_uart_put((uint8_t)ch));
    return ch;
}

after:

int __putchar(int ch, __printf_tag_ptr p_file)
{
    UNUSED_PARAMETER(p_file);

    UNUSED_VARIABLE(app_uart_put((uint8_t)ch));
    return ch;
}

[madhu]

Hi , I observed the same issue with 3.40 SES and SDK_15...
The above solution worked fine .