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Re: malloc attributes and realloc
"Zack Weinberg" <zack@codesourcery.com> writes:
| Gabriel Dos Reis <gdr@integrable-solutions.net> writes:
|
| > | This isn't directly relevant to the current thread, but another aspect of
| > | malloc-like functions came up recently: the memory they return is writable.
| > | I.e., if char *p was returned by an attribute(malloc) function, then
| > | if (*p != 'a')
| > | *p = 'a';
| > |
| > | can be safely optimized into
| > | *p = 'a';
| >
| > That transformation caanot be applied for pointers returned by
| > realloc, in general.
|
| Huh? Are you asserting that realloc may return a pointer to read-only
| memory?
No, I'm saying that the test
if (*p != 'a')
cannot not be "skipped" (or turned into true) because there might be a
data there that actually is an 'a'.
-- Gaby