Re: [avr-chat] troublesome compilation warning

[jepler]

The following program compiles without warnings with the following flags:
   -mmcu=at90s2313 -ansi -pedantic -Wall -ffreestanding -c extension.c
on avr-gcc 3.2.2.  It is the use of __extension__ that makes the use of the
non-ANSI construct not give a warning.  With the same flags, the PSTR
definition from pgmspace.h (shown in the comment) does print the warning you
mention.

So, anyway, add __extension__ and gcc will not complain about your use of a
non-ANSI construct.

Jeff

/* -------------------------------------------------------------------- */
/* avr-gcc -mmcu=at90s2313 -ansi -pedantic -Wall -ffreestanding         */
/* -------------------------------------------------------------------- */
#include <avr/pgmspace.h>
#undef PSTR
/* #define PSTR(s) ({static char __c[] PROGMEM = (s); __c;}) */
#define PSTR(s) (__extension__({static char __c[] PROGMEM = (s); __c;}))

extern void f(const char *);

void main(void) { f(PSTR("hi")); }
/* -------------------------------------------------------------------- */

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