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Re: 'char **' <-> 'unsigned char **' and aliasing/punning in C / GNU C


Hello,

FYI, I got word back from Joseph Meyers on a separate
channel, and his answer was:

  It's not valid.  char and unsigned char can alias, but
  not char * and unsigned char *.

Regarding char * and const char *, I then asked:

  Can char * and const char * alias?

He said:

  Not in C (but they can in C++, where you can implicitly convert from char
  ** to const char *const *, although not from char ** to const char **).


We're going to avoid these casts in GDB then, and do instead
things like:

gdb_byte *buf;
char *c;
...
bufsiz = target_read_alloc (&current_target, TARGET_OBJECT_AVR,
			    "avr.io_reg", &buf);
c = (char *) buf;


Thanks a lot,
-- 
Pedro Alves


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