On Wed, 11 Oct 2023 at 05:48, Joern Rennecke
<joern.rennecke@embecosm.com> wrote:

> I've though about this some more, and we need something that's simple for
> dejagnu and simple to describe.
>
> So I propose we look at the first character of the regexp, and if it's neither
> ^ nor \ (neither caret nor backslash), we consider the regexp un-anchored,
> and prepend ^[^"]* , so it won't allow a match after a double quote.
> Then document this in sourcebuild.texi, with some mention of lto information
> and stabs, and also mentioning that if you really want to match irrespective
> of a leading quote, you can prepend ^.* to your regexp.
> There are good reasons to be more specific with your regexps in general,
> but the matches in LTO are particularily damaging because they appear
> semi-random, so often escape a regression test when the test is made,
> only to surface during somebody else's regression test.

I've tried this, and it turns out that we actually have a lot of tests that scan
after or even inside quotes.  I've adjusted the C part of the
testsuite, and parts
of the c++ testsuite, haven't even looked at fortran regressions, but the thing
gets uncomfortably large.  With so many tests affected, this would also cause
headaches when merging branches.

I've attached the patch to illustrate why it's probably not such a good idea.
I have a different approach now which I'll post next.