Re: [PATCH] Fortran: Fix diagnostic for ambiguous pointer function assignment [PR80012]

Hi Gonzalo,

I've pushed the corrected version now as r16-7653-g82cc94e5fb69d1 .
Let's hope that there is no further fallout, and have an eye on
the test results.

Best,
Harald

On 2/22/26 15:57, Gonzalosilvalde wrote:
> From: Gonzalo Silvalde Blanco <[email protected]>
> 
> The error message for an ambiguous pointer function assignment contained a
> FIXME and an embedded newline that the diagnostics printer does not handle.
> Split the single gfc_error call into a gfc_error for the main diagnostic
> and an inform note for the F2008 explanation.
> 
> 	PR fortran/80012
> 
> gcc/fortran/ChangeLog:
> 
> 	* symbol.cc (gfc_add_procedure): Split error into gfc_error and
> 	inform.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* gfortran.dg/pr80012.f90: New test.
> 
> Signed-off-by: Gonzalo Silvalde Blanco <[email protected]>
> ---
> Hi Harald,
> 
> I investigated the regression caused by my previous commit and I
> believe I found the root cause.
> 
> The problem was the use of auto_diagnostic_group in gfc_add_procedure.
> When that object is created, it increments the diagnostic group nesting
> counter. Then, when gfc_error internally calls set_diagnostic_buffer,
> it hits this assert in diagnostics/buffering.cc:50:
> 
>      gcc_assert (m_diagnostic_groups.m_group_nesting_depth == 0);
> 
> ...which I think causes the ICE, since the nesting depth is no longer
> 0 at that point.
> 
> Looking at other uses of inform() in the Fortran frontend, none of them
> wrap the call in an auto_diagnostic_group, and they work fine. So I
> simply removed the auto_diagnostic_group wrapper.
> 
> I ran make check-fortran on both my patched version and a clean
> mainline checkout. Both now give identical results in my PC.
> 
> Best regards,
> Gonzalo
> 
>   gcc/fortran/symbol.cc                 | 22 +++++++++++-----------
>   gcc/testsuite/gfortran.dg/pr80012.f90 | 14 ++++++++++++++
>   2 files changed, 25 insertions(+), 11 deletions(-)
>   create mode 100644 gcc/testsuite/gfortran.dg/pr80012.f90
> 
> diff --git a/gcc/fortran/symbol.cc b/gcc/fortran/symbol.cc
> index 5ff14e27b94..9edfb8e9eeb 100644
> --- a/gcc/fortran/symbol.cc
> +++ b/gcc/fortran/symbol.cc
> @@ -24,6 +24,7 @@ along with GCC; see the file COPYING3.  If not see
>   #include "coretypes.h"
>   #include "options.h"
>   #include "gfortran.h"
> +#include "diagnostic-core.h"
>   #include "parse.h"
>   #include "match.h"
>   #include "constructor.h"
> @@ -1887,19 +1888,18 @@ gfc_add_procedure (symbol_attribute *attr, procedure_type t,
>     if (attr->proc != PROC_UNKNOWN && !attr->module_procedure
>         && attr->access == ACCESS_UNKNOWN)
>       {
> -      if (attr->proc == PROC_ST_FUNCTION && t == PROC_INTERNAL
> -	  && !gfc_notification_std (GFC_STD_F2008))
> -	gfc_error ("%s procedure at %L is already declared as %s "
> -		   "procedure. \nF2008: A pointer function assignment "
> -		   "is ambiguous if it is the first executable statement "
> -		   "after the specification block. Please add any other "
> -		   "kind of executable statement before it. FIXME",
> +      gfc_error ("%s procedure at %L is already declared as %s procedure",
>   		 gfc_code2string (procedures, t), where,
>   		 gfc_code2string (procedures, attr->proc));
> -      else
> -	gfc_error ("%s procedure at %L is already declared as %s "
> -		   "procedure", gfc_code2string (procedures, t), where,
> -		   gfc_code2string (procedures, attr->proc));
> +      if (attr->proc == PROC_ST_FUNCTION && t == PROC_INTERNAL
> +	  && !gfc_notification_std (GFC_STD_F2008))
> +	{
> +	  inform (gfc_get_location (where),
> +		  "F2008: A pointer function assignment is ambiguous if it is "
> +		  "the first executable statement after the specification "
> +		  "block.  Please add any other kind of executable "
> +		  "statement before it");
> +	}
>   
>         return false;
>       }
> diff --git a/gcc/testsuite/gfortran.dg/pr80012.f90 b/gcc/testsuite/gfortran.dg/pr80012.f90
> new file mode 100644
> index 00000000000..da626d565d8
> --- /dev/null
> +++ b/gcc/testsuite/gfortran.dg/pr80012.f90
> @@ -0,0 +1,14 @@
> +! { dg-do compile }
> +! { dg-options "-std=gnu" }
> +! PR fortran/80012
> +! Test that the error message for ambiguous pointer function assignment
> +! is split into an error and an informational note, without FIXME.
> +
> +two() = 7
> +contains
> +  function two () ! { dg-error "INTERNAL-PROC procedure at .1. is already declared as STATEMENT-PROC procedure" }
> +! { dg-message "F2008: A pointer function assignment is ambiguous" "" { target *-*-* } 9 }
> +    integer, pointer  :: two
> +    allocate(two)
> +  end function two
> +end