diff mbox

fortran/67758 -- Prevent ICE caused by misplaced COMMON

Message ID 560E4E26.6000302@sfr.fr
State New
Headers show

Commit Message

Mikael Morin Oct. 2, 2015, 9:28 a.m. UTC 
Le 01/10/2015 18:30, Steve Kargl a écrit :
> I'm fine with your patch, although I find the error message
> to be somewhat confusing as no procedure appears in COMMON.

Well, XX is implicitly a procedure.

> The call-stmt in the code is the start of an execution-construct.
> A common-stmt is not allowed in an execution-construct.  At
> least, that's how I intepret the BNF in 2.1 of F2008.
>
The error message appears too soon, before we finish parsing the common 
statement.  If it's delayed, as with the following additional patch, the 
common statements is properly rejected:

common_24.f:10:72:

        COMMON /FMCOM / XX(80 000 000) ! { dg-error "conflicts with 
COMMON" }
                                                                         1
Error: Unexpected COMMON statement at (1)
common_24.f:8:72:

Error: PROCEDURE attribute conflicts with COMMON attribute in ‘xx’ at (1)

This needs a little more polishing (location missing in the second error 
message), then let's see how the testsuite likes it.

Mikael

Comments

Steve Kargl Oct. 2, 2015, 4:44 p.m. UTC | #1 
On Fri, Oct 02, 2015 at 11:28:06AM +0200, Mikael Morin wrote:
> Le 01/10/2015 18:30, Steve Kargl a écrit :
> > I'm fine with your patch, although I find the error message
> > to be somewhat confusing as no procedure appears in COMMON.
> 
> Well, XX is implicitly a procedure.
> 

Yes, I understamf what gfortran is doing.  However, I
less fluent Fortran programmer who expects XX to be 
an array may be confused by error message.

> > The call-stmt in the code is the start of an execution-construct.
> > A common-stmt is not allowed in an execution-construct.  At
> > least, that's how I intepret the BNF in 2.1 of F2008.
> >
> The error message appears too soon, before we finish parsing the common 
> statement.  If it's delayed, as with the following additional patch, the 
> common statements is properly rejected:
> 
> common_24.f:10:72:
> 
>         COMMON /FMCOM / XX(80 000 000) ! { dg-error "conflicts with 
> COMMON" }
>                                                                          1
> Error: Unexpected COMMON statement at (1)
> common_24.f:8:72:
> 
> Error: PROCEDURE attribute conflicts with COMMON attribute in ???xx??? at (1)
> 
> This needs a little more polishing (location missing in the second error 
> message), then let's see how the testsuite likes it.
> 

While I prefer the first error message above, if it requires
too much polish, then at least commit your first patch to cure
the ICE.  We can worry about polish later.
diff mbox

Patch

Index: match.c
===================================================================
--- match.c	(révision 228170)
+++ match.c	(copie de travail)
@@ -4376,9 +4376,6 @@  gfc_match_common (void)
  		goto cleanup;
  	    }

-	  if (!gfc_add_in_common (&sym->attr, sym->name, NULL))
-	    goto cleanup;
-
  	  if (tail != NULL)
  	    tail->common_next = sym;
  	  else
Index: resolve.c
===================================================================
--- resolve.c	(révision 228170)
+++ resolve.c	(copie de travail)
@@ -918,6 +918,9 @@  resolve_common_vars (gfc_symbol *sym, bool named_c

    for (; csym; csym = csym->common_next)
      {
+      if (!gfc_add_in_common (&csym->attr, csym->name, NULL))
+	continue;
+
        if (csym->value || csym->attr.data)
  	{
  	  if (!csym->ns->is_block_data)