Re: problems with powerpc-linux-gcc

In message [ref] you wrote:

I'm having trouble with compiling some code that I will use for our
embedded system when booting the system.

This is an old story: buggy code does not work.  I  always  have  the
same problem ;-)

The function that I'm having trouble with is the printf function. I used

To  be  more  specific:  you  have  problems  with   _your_   (buggy)
_implementation_  of  the said function. It works fine for many, many
people.

In the powerpc environemnt (using GNU powerpc-linux-gcc cross compiler),
the compiler puts the arguments in registers instead of the stack ; due

Right. Which is a Good Thing (TM) to do.

static char *do_printf(char *buf, const char *fmt, const int *dp)
{
...
}


void printf(const char *fmt, ...)

Please note that a conforming implementation of printf() returns "int".

{
   char buf[256],*p;
   p = buf;
   do_printf(buf, fmt, ((const int *)&fmt)+1);
   while (*p) putchar(*p++);
}

This code is WRONG!

You MUST do something like that:

#include <stdarg.h>
...
... do_printf(..., const char *fmt, va_list args)

int printf(const char *fmt, ...)
{
	va_list args;
	va_start(args, fmt);
	... do_printf(..., fmt, args);
	va_end(args);

	return (number_of_printed_chars);
}


... and RTFM: man stdarg(3)

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
"You ain't experienced..." "Well, nor are you." "That's true. But the
point is ... the point is ... the point is we've been not experienced
for a lot longer than you. We've got  a  lot  of  experience  of  not
having any experience."           - Terry Pratchett, _Witches Abroad_

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