Set RTX_UNCHANGING is readonly_field_p when clearing

Mark Mitchell
Mon Apr 21 22:29:00 GMT 2003

On Mon, 2003-04-21 at 15:18, Richard Kenner wrote:
>     There is nothing wrong with the manual explaining how to get the bit set
>     correctly.
> Done thusly, to avoid duplicating information which might change:

Well, this is progress.

> ! references conflict.  See @code{tree_dependence} in @file{alias.c} for

There's no such function; you mean true_dependence.

And that function doesn't say anywhere that you must set this flag when
writing to any part of a structure, or reading from the entire
sturcture, or whatever.  There's a paragraph in there that might imply
this, but that is all.

Like lots other gotchas, this is something to call out so that people
are easily aware of it.  "Look in a source file and try to divine
meaning out of reading some comments there" is not as useful as "Do it
this way."  Virtually all information in the manual duplicates
information derivable from the source code, so this not really a big

Just put the rule in the manual.   

Mark Mitchell
CodeSourcery, LLC

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