Re: [gfortran] Fix PR 16161

[Steven Bosscher <stevenb at suse dot de>]

On Tuesday 29 June 2004 22:54, Tobias Schlüter wrote:
> PR 16161 deals with a funny bug in our matchers:
>   IMPLICIT CHARACTER (c); END
> would yield a syntax error, because (c) would be recognized as a
> character length, and this would in turn mess up parsing. This patch
> fixes this by making gfc_match_typespec not deal with character legths
> when parsing the implicit statement.

It's interesting to see how our "greedy" template matcher works sometimes.
I wish we'd try to parse one token at a time and gradually move to a more
traditional recursive-descent-like parser with backtracking.  Oh well...

> Since I now had to call
> match_char_spec from gfc_match_implicit, I changed the distribution of
> the functions to files somewhat: I moved gfc_match_implicit to decl.c
> and also moved gfc_match_implicit_none to keep those functions together.
> After this, gfc_match_type_spec could become a static function.

That does make the patch a bit harder to review ;-)

> Compiled and tested on i686-pc-linux. I will add the testcase from the
> PR to the compile testsuite.

This is OK

Note...

+  if (c != '(')
+    {
+      gfc_error ("Missing character range in IMPLICIT at %C");
+      goto bad;
+    }

+bad:
+  gfc_syntax_error (ST_IMPLICIT);
+
+  gfc_current_locus = cur_loc;
+  return MATCH_ERROR;
+}

we really shouldn't issue two error messages for the same error here.

Gr.
Steven