Re: [PATCH] gfortran: Respect target's NO_DOT_IN_LABEL in trans-common.cc

[Tobias Burnus <tobias@codesourcery.com>]

On 10.02.22 11:07, Roger Sayle wrote:

> The fix is to tweak trans-common.cc to respect the target's NO_DOT_IN_LABEL
> (and NO_DOLLAR_IN_LABEL) when generating internal equiv.%d symbols.

In general, I think the patch is okay – but as '_' is a valid identifier
and with -fdollar-ok '$' is valid as well, I wonder whether there should
be a prefix and/or a capital letter. Namely:

+#if !defined (NO_DOT_IN_LABEL)
+#define GFC_EQUIV_FMT "equiv.%d"
+#elif !defined (NO_DOLLAR_IN_LABEL)
+#define GFC_EQUIV_FMT "equiv$%d"
+#else
+#define GFC_EQUIV_FMT "equiv_%d"
+#endif

The first one we want to keep as is for backwards compatibility. And
the '.' is fine in this regard. But I think for the other two, we need
to do more, e.g., '_Equiv' + '$%d' / '_%d'. The '_' and capital letter
should place everything into the compiler namespace (in terms of C/C++)
and Fortran itself requires for a name (case insensitive, lower cased by
gfortran): [A-Z][A-Z0-9_]* – thus, '_E' contains two characters not
accessible in a normal Fortran program (ignoring bind(C,name="...").

If the _Equiv[_$]%d sounds sensible to you: Please change; if not,
what concerns do you have?

> Ok for mainline?
OK with changing the prefix for the non-dot variant.

Tobias

> 2022-02-10  Roger Sayle  <roger@nextmovesoftware.com>
>
> gcc/fortran/ChangeLog
>       * trans-common.cc (GFC_EQUIV_FMT): New macro respecting the
>       target's NO_DOT_IN_LABEL and NO_DOLLAR_IN_LABEL preferences.
>       (build_equiv_decl): Use GFC_EQUIV_FMT here.

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