Canonicalization of function pointers

[Andreas Schwab]

"John David Anglin" <dave@hiauly1.hia.nrc.ca> writes:

|> The code snippet below demonstrates a problem in comparing a void *
|> to a function pointer.  I believe this is a gcc extension and is not
|> allowed in ISO C.

Yes, it is even a constraint violation:

6.5.9 Equality operators

Constraints

2  One of the following shall hold:

   - both operands have arithmetic type;

   - both operands are pointers to qualified or unqualified versions of
     compatible types;

   - one operand is a pointer to an object or incomplete type and the
     other is a pointer to a qualified or unqualified version of void; or

   - one operand is a pointer and the other is a null pointer constant.

Andreas.

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Andreas Schwab, SuSE Labs, schwab@suse.de
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