[Bug tree-optimization/89672] NULL pointer check optimized out for the return value of memchr(NULL, c, 0)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89672 --- Comment #4 from Damon Revoe --- And that fact is used by the optimizer. I see. Thanks!
[Bug tree-optimization/89672] NULL pointer check optimized out for the return value of memchr(NULL, c, 0)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89672 Jakub Jelinek changed: What|Removed |Added CC||jakub at gcc dot gnu.org --- Comment #3 from Jakub Jelinek --- C says e.g. for memchr: "The memchr function locates the first occurrence of c (converted to an unsigned char) in the initial n characters (each interpreted as unsigned char) of the object pointed to by s." and elsewhere: "If a null pointer constant is converted to a pointer type, the resulting pointer, called a null pointer, is guaranteed to compare unequal to a pointer to any object or function." As memchr first argument must point to an object and NULL does not point to any object, NULL is not a valid value. It is similar to memcpy (NULL, NULL, 0) or memset (NULL, 0, 0) etc. being invalid.
[Bug tree-optimization/89672] NULL pointer check optimized out for the return value of memchr(NULL, c, 0)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89672 --- Comment #2 from Damon Revoe --- Oops. Ironically, I checked the man page for whether NULL was a valid argument. It just didn't occur to me to check the source. Duh. Thank you for your time!
[Bug tree-optimization/89672] NULL pointer check optimized out for the return value of memchr(NULL, c, 0)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89672 Richard Biener changed: What|Removed |Added Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #1 from Richard Biener --- I don't see that NULL is a valid first argument to memchr, in fact it is declared with nonnull(1).
