Re: [PATCH] PR fortran/63797 - Bogus ambiguous reference to 'sqrt'

[Tobias Burnus <tobias@codesourcery.com>]

On 16.04.21 09:06, Bernhard Reutner-Fischer via Fortran wrote:

> Does this change the module format in an incompatible way, i.e. does
> this require a module format version bump?
Not having looked it in detail but I doubt it – it is just a symbol
which is not output.
> What happens when we read an existing module that names an intrinsic?
> Without bumping the module version, we'd run into the same issue as
> before, don't we?
...
> Even if we'd skip reading existing intrinsic now, we'd break interop
> with older compiler versions if we would stop writing them without
> bumping the module format, i think?

 From the function name ("write_symtree"), gfortran only skips writing it;
it still reads all symtrees which are in the .mod file.
As this is the only change of Harald's patch, it should be:

* .mod by old compiler → used by new/old compiler: bogus error for 'sqrt'.

* .mod by new compiler → used by new/old compiler: works after the patch

Thus, from that side there should be no issue.
And I see no point in bumping the .mod version to force the recompilation;
those running into the corner case can still do 'make clean && make' and
all others can keep using the old version.

Tobias

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