Re: [PATCH 16/16] fix handling of integer constant expressions

From: Segher Boessenkool
Date: Sun Jun 24 2007 - 15:09:55 EST


If I understand correctly what bugs you are talking about,
most (all?) of those were solved in the dark ages already
(i.e., the 3.x series).

Alas, no. gcc is amazingly (and inconsistently) sloppy about the
things it accepts as integer constant expressions.

Ah yes, now I see what you were talking about. Most of this
is well-known, but feel free to file more PRs :-)

It certainly is not a valid C

Why not? Nothing in the C standard says all your externs
have to be defined in some other translation unit you link
with AFAIK.

It's not about externs. It's about things like

unsigned n;
int a[] = {[n - n + n - n] = 1};

And yes, gcc does eat that.

Yeah.

With -pedantic -std=c99, at that.
However,

unsigned n;
int a[] = {[n + n - n - n] = 1};

gets you error: nonconstant array index in initializer

And that's 4.1, not 3.x...

Why are you using such an ancient compiler? :-)
(Not that it is fixed in the current release though).


Segher

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