[PATCHv3, gfortran] Escalate failure when Hollerith constant to real conversion fails [PR103628]

[PATCHv3, gfortran] Escalate failure when Hollerith constant to real conversion fails [PR103628]

[HAO CHEN GUI]

Hi,
  The patch escalates the failure when Hollerith constant to real conversion
fails in native_interpret_expr. It finally reports an "Cannot simplify
expression" error in do_simplify method.

  The patch of pr95450 added a verification for decoding/encoding checking
in native_interpret_expr. native_interpret_expr may fail on real type
conversion and returns a NULL tree then. But upper layer calls don't handle
the failure so that an ICE is reported when the verification fails.

  IBM long double is an example. It doesn't have a unique memory presentation
for some real values. So it may not pass the verification. The new test
case shows the problem.

  errorcount is used to check if an error is already reported or not when
getting a bad expr. Buffered errors need to be excluded as they don't
increase error count either.

  The patch passed regression test on Power and x86 linux platforms.

Gui Haochen
Thanks

ChangeLog
2023-03-07  Haochen Gui <guihaoc@linux.ibm.com>

gcc/
	PR target/103628
	* fortran/target-memory.cc (gfc_interpret_float): Return FAIL when
	native_interpret_expr gets a NULL tree.
	* fortran/arith.cc (gfc_hollerith2real): Return NULL when
	gfc_interpret_float fails.
	* fortran/error.cc (gfc_buffered_p): Define.
	* fortran/gfortran.h (gfc_buffered_p): Declare.
	* fortran/intrinsic.cc: Add diagnostic.h to include list.
	(do_simplify): Save errorcount and check it at finish.  Report a
	"Cannot simplify expression" error on a bad result if error count
	doesn't change and no other errors buffered.

gcc/testsuite/
	PR target/103628
	* gfortran.dg/pr103628.f90: New.

Co-Authored-By: Tobias Burnus <tobias@codesourcery.com>

patch.diff
diff --git a/gcc/fortran/arith.cc b/gcc/fortran/arith.cc
index c0d12cfad9d..d3d38c7eb6a 100644
--- a/gcc/fortran/arith.cc
+++ b/gcc/fortran/arith.cc
@@ -2752,10 +2752,12 @@ gfc_hollerith2real (gfc_expr *src, int kind)
   result = gfc_get_constant_expr (BT_REAL, kind, &src->where);

   hollerith2representation (result, src);
-  gfc_interpret_float (kind, (unsigned char *) result->representation.string,
-		       result->representation.length, result->value.real);
-
-  return result;
+  if (gfc_interpret_float (kind,
+			   (unsigned char *) result->representation.string,
+			   result->representation.length, result->value.real))
+    return result;
+  else
+    return NULL;
 }

 /* Convert character to real.  The constant will be padded or truncated.  */
diff --git a/gcc/fortran/error.cc b/gcc/fortran/error.cc
index 214fb78ba7b..872d42e731e 100644
--- a/gcc/fortran/error.cc
+++ b/gcc/fortran/error.cc
@@ -49,6 +49,13 @@ static gfc_error_buffer error_buffer;
 static output_buffer *pp_error_buffer, *pp_warning_buffer;
 static int warningcount_buffered, werrorcount_buffered;

+/* Return buffered_p.  */
+bool
+gfc_buffered_p (void)
+{
+  return buffered_p;
+}
+
 /* Return true if there output_buffer is empty.  */

 static bool
diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index 219ef8c7612..edfe11796a6 100644
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -3328,6 +3328,7 @@ void gfc_internal_error (const char *, ...) ATTRIBUTE_NORETURN ATTRIBUTE_GCC_GFC
 void gfc_clear_error (void);
 bool gfc_error_check (void);
 bool gfc_error_flag_test (void);
+bool gfc_buffered_p (void);

 notification gfc_notification_std (int);
 bool gfc_notify_std (int, const char *, ...) ATTRIBUTE_GCC_GFC(2,3);
diff --git a/gcc/fortran/intrinsic.cc b/gcc/fortran/intrinsic.cc
index e89131f5a71..9d049001a51 100644
--- a/gcc/fortran/intrinsic.cc
+++ b/gcc/fortran/intrinsic.cc
@@ -25,6 +25,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "options.h"
 #include "gfortran.h"
 #include "intrinsic.h"
+#include "diagnostic.h" /* For errorcount.  */

 /* Namespace to hold the resolved symbols for intrinsic subroutines.  */
 static gfc_namespace *gfc_intrinsic_namespace;
@@ -4620,6 +4621,7 @@ do_simplify (gfc_intrinsic_sym *specific, gfc_expr *e)
 {
   gfc_expr *result, *a1, *a2, *a3, *a4, *a5, *a6;
   gfc_actual_arglist *arg;
+  int old_errorcount = errorcount;

   /* Max and min require special handling due to the variable number
      of args.  */
@@ -4708,7 +4710,12 @@ do_simplify (gfc_intrinsic_sym *specific, gfc_expr *e)

 finish:
   if (result == &gfc_bad_expr)
-    return false;
+    {
+      if (errorcount == old_errorcount
+	  && (gfc_buffered_p () && !gfc_error_flag_test ()))
+       gfc_error ("Cannot simplify expression at %L", &e->where);
+      return false;
+    }

   if (result == NULL)
     resolve_intrinsic (specific, e);	/* Must call at run-time */
diff --git a/gcc/fortran/target-memory.cc b/gcc/fortran/target-memory.cc
index 7ce7d736629..0c47aa6b842 100644
--- a/gcc/fortran/target-memory.cc
+++ b/gcc/fortran/target-memory.cc
@@ -416,11 +416,14 @@ gfc_interpret_float (int kind, unsigned char *buffer, size_t buffer_size,
 		     mpfr_t real)
 {
   gfc_set_model_kind (kind);
-  mpfr_init (real);
-  gfc_conv_tree_to_mpfr (real,
-			 native_interpret_expr (gfc_get_real_type (kind),
-						buffer, buffer_size));

+  tree source = native_interpret_expr (gfc_get_real_type (kind), buffer,
+				       buffer_size);
+  if (!source)
+    return 0;
+
+  mpfr_init (real);
+  gfc_conv_tree_to_mpfr (real, source);
   return size_float (kind);
 }

diff --git a/gcc/testsuite/gfortran.dg/pr103628.f90 b/gcc/testsuite/gfortran.dg/pr103628.f90
new file mode 100644
index 00000000000..255d5bdd73e
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr103628.f90
@@ -0,0 +1,14 @@
+! { dg-do compile { target powerpc*-*-* } }
+! { dg-options "-O2 -mabi=ibmlongdouble" }
+
+! Test to ensure that it reports an "Cannot simplify expression" error
+! instead of throwing an ICE when the memory represent of the HOLLERITH
+! string is not unique with ibm long double encoding.
+
+program main
+  integer, parameter :: k = 16
+  real(kind = k):: b = 4h1234
+end program main
+
+! { dg-warning "Conversion from HOLLERITH" "warning" { target powerpc*-*-* } 10 }
+! { dg-error "Cannot simplify expression" "error" { target powerpc*-*-* } 10 }

Ping [PATCHv3, gfortran] Escalate failure when Hollerith constant to real conversion fails [PR103628]

[HAO CHEN GUI]

Hi,
  Gently ping this:
  https://gcc.gnu.org/pipermail/gcc-patches/2023-March/613497.html

Thanks
Gui Haochen

在 2023/3/7 16:55, HAO CHEN GUI 写道:
> Hi,
>   The patch escalates the failure when Hollerith constant to real conversion
> fails in native_interpret_expr. It finally reports an "Cannot simplify
> expression" error in do_simplify method.
> 
>   The patch of pr95450 added a verification for decoding/encoding checking
> in native_interpret_expr. native_interpret_expr may fail on real type
> conversion and returns a NULL tree then. But upper layer calls don't handle
> the failure so that an ICE is reported when the verification fails.
> 
>   IBM long double is an example. It doesn't have a unique memory presentation
> for some real values. So it may not pass the verification. The new test
> case shows the problem.
> 
>   errorcount is used to check if an error is already reported or not when
> getting a bad expr. Buffered errors need to be excluded as they don't
> increase error count either.
> 
>   The patch passed regression test on Power and x86 linux platforms.
> 
> Gui Haochen
> Thanks
> 
> ChangeLog
> 2023-03-07  Haochen Gui <guihaoc@linux.ibm.com>
> 
> gcc/
> 	PR target/103628
> 	* fortran/target-memory.cc (gfc_interpret_float): Return FAIL when
> 	native_interpret_expr gets a NULL tree.
> 	* fortran/arith.cc (gfc_hollerith2real): Return NULL when
> 	gfc_interpret_float fails.
> 	* fortran/error.cc (gfc_buffered_p): Define.
> 	* fortran/gfortran.h (gfc_buffered_p): Declare.
> 	* fortran/intrinsic.cc: Add diagnostic.h to include list.
> 	(do_simplify): Save errorcount and check it at finish.  Report a
> 	"Cannot simplify expression" error on a bad result if error count
> 	doesn't change and no other errors buffered.
> 
> gcc/testsuite/
> 	PR target/103628
> 	* gfortran.dg/pr103628.f90: New.
> 
> Co-Authored-By: Tobias Burnus <tobias@codesourcery.com>
> 
> patch.diff
> diff --git a/gcc/fortran/arith.cc b/gcc/fortran/arith.cc
> index c0d12cfad9d..d3d38c7eb6a 100644
> --- a/gcc/fortran/arith.cc
> +++ b/gcc/fortran/arith.cc
> @@ -2752,10 +2752,12 @@ gfc_hollerith2real (gfc_expr *src, int kind)
>    result = gfc_get_constant_expr (BT_REAL, kind, &src->where);
> 
>    hollerith2representation (result, src);
> -  gfc_interpret_float (kind, (unsigned char *) result->representation.string,
> -		       result->representation.length, result->value.real);
> -
> -  return result;
> +  if (gfc_interpret_float (kind,
> +			   (unsigned char *) result->representation.string,
> +			   result->representation.length, result->value.real))
> +    return result;
> +  else
> +    return NULL;
>  }
> 
>  /* Convert character to real.  The constant will be padded or truncated.  */
> diff --git a/gcc/fortran/error.cc b/gcc/fortran/error.cc
> index 214fb78ba7b..872d42e731e 100644
> --- a/gcc/fortran/error.cc
> +++ b/gcc/fortran/error.cc
> @@ -49,6 +49,13 @@ static gfc_error_buffer error_buffer;
>  static output_buffer *pp_error_buffer, *pp_warning_buffer;
>  static int warningcount_buffered, werrorcount_buffered;
> 
> +/* Return buffered_p.  */
> +bool
> +gfc_buffered_p (void)
> +{
> +  return buffered_p;
> +}
> +
>  /* Return true if there output_buffer is empty.  */
> 
>  static bool
> diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
> index 219ef8c7612..edfe11796a6 100644
> --- a/gcc/fortran/gfortran.h
> +++ b/gcc/fortran/gfortran.h
> @@ -3328,6 +3328,7 @@ void gfc_internal_error (const char *, ...) ATTRIBUTE_NORETURN ATTRIBUTE_GCC_GFC
>  void gfc_clear_error (void);
>  bool gfc_error_check (void);
>  bool gfc_error_flag_test (void);
> +bool gfc_buffered_p (void);
> 
>  notification gfc_notification_std (int);
>  bool gfc_notify_std (int, const char *, ...) ATTRIBUTE_GCC_GFC(2,3);
> diff --git a/gcc/fortran/intrinsic.cc b/gcc/fortran/intrinsic.cc
> index e89131f5a71..9d049001a51 100644
> --- a/gcc/fortran/intrinsic.cc
> +++ b/gcc/fortran/intrinsic.cc
> @@ -25,6 +25,7 @@ along with GCC; see the file COPYING3.  If not see
>  #include "options.h"
>  #include "gfortran.h"
>  #include "intrinsic.h"
> +#include "diagnostic.h" /* For errorcount.  */
> 
>  /* Namespace to hold the resolved symbols for intrinsic subroutines.  */
>  static gfc_namespace *gfc_intrinsic_namespace;
> @@ -4620,6 +4621,7 @@ do_simplify (gfc_intrinsic_sym *specific, gfc_expr *e)
>  {
>    gfc_expr *result, *a1, *a2, *a3, *a4, *a5, *a6;
>    gfc_actual_arglist *arg;
> +  int old_errorcount = errorcount;
> 
>    /* Max and min require special handling due to the variable number
>       of args.  */
> @@ -4708,7 +4710,12 @@ do_simplify (gfc_intrinsic_sym *specific, gfc_expr *e)
> 
>  finish:
>    if (result == &gfc_bad_expr)
> -    return false;
> +    {
> +      if (errorcount == old_errorcount
> +	  && (gfc_buffered_p () && !gfc_error_flag_test ()))
> +       gfc_error ("Cannot simplify expression at %L", &e->where);
> +      return false;
> +    }
> 
>    if (result == NULL)
>      resolve_intrinsic (specific, e);	/* Must call at run-time */
> diff --git a/gcc/fortran/target-memory.cc b/gcc/fortran/target-memory.cc
> index 7ce7d736629..0c47aa6b842 100644
> --- a/gcc/fortran/target-memory.cc
> +++ b/gcc/fortran/target-memory.cc
> @@ -416,11 +416,14 @@ gfc_interpret_float (int kind, unsigned char *buffer, size_t buffer_size,
>  		     mpfr_t real)
>  {
>    gfc_set_model_kind (kind);
> -  mpfr_init (real);
> -  gfc_conv_tree_to_mpfr (real,
> -			 native_interpret_expr (gfc_get_real_type (kind),
> -						buffer, buffer_size));
> 
> +  tree source = native_interpret_expr (gfc_get_real_type (kind), buffer,
> +				       buffer_size);
> +  if (!source)
> +    return 0;
> +
> +  mpfr_init (real);
> +  gfc_conv_tree_to_mpfr (real, source);
>    return size_float (kind);
>  }
> 
> diff --git a/gcc/testsuite/gfortran.dg/pr103628.f90 b/gcc/testsuite/gfortran.dg/pr103628.f90
> new file mode 100644
> index 00000000000..255d5bdd73e
> --- /dev/null
> +++ b/gcc/testsuite/gfortran.dg/pr103628.f90
> @@ -0,0 +1,14 @@
> +! { dg-do compile { target powerpc*-*-* } }
> +! { dg-options "-O2 -mabi=ibmlongdouble" }
> +
> +! Test to ensure that it reports an "Cannot simplify expression" error
> +! instead of throwing an ICE when the memory represent of the HOLLERITH
> +! string is not unique with ibm long double encoding.
> +
> +program main
> +  integer, parameter :: k = 16
> +  real(kind = k):: b = 4h1234
> +end program main
> +
> +! { dg-warning "Conversion from HOLLERITH" "warning" { target powerpc*-*-* } 10 }
> +! { dg-error "Cannot simplify expression" "error" { target powerpc*-*-* } 10 }
> 

Re: [PATCHv3, gfortran] Escalate failure when Hollerith constant to real conversion fails [PR103628]

[Tobias Burnus]

Hi,

sorry for the belated reply.

On 07.03.23 09:55, HAO CHEN GUI wrote:
> 2023-03-07  Haochen Gui <guihaoc@linux.ibm.com>
>
> gcc/
>       PR target/103628
>       * fortran/target-memory.cc (gfc_interpret_float): Return FAIL when
>       native_interpret_expr gets a NULL tree.
>       * fortran/arith.cc (gfc_hollerith2real): Return NULL when
>       gfc_interpret_float fails.
>       * fortran/error.cc (gfc_buffered_p): Define.
>       * fortran/gfortran.h (gfc_buffered_p): Declare.
>       * fortran/intrinsic.cc: Add diagnostic.h to include list.
>       (do_simplify): Save errorcount and check it at finish.  Report a
>       "Cannot simplify expression" error on a bad result if error count
>       doesn't change and no other errors buffered.
>
> gcc/testsuite/
>       PR target/103628
>       * gfortran.dg/pr103628.f90: New.
>
> Co-Authored-By: Tobias Burnus <tobias@codesourcery.com>
...
> --- a/gcc/fortran/intrinsic.cc
> +++ b/gcc/fortran/intrinsic.cc
...
> @@ -4708,7 +4710,12 @@ do_simplify (gfc_intrinsic_sym *specific, gfc_expr *e)
>
>   finish:
>     if (result == &gfc_bad_expr)
> -    return false;
> +    {
> +      if (errorcount == old_errorcount
> +       && (gfc_buffered_p () && !gfc_error_flag_test ()))
> +       gfc_error ("Cannot simplify expression at %L", &e->where);
> +      return false;
> +    }

The condition looks wrong. Shouldn't it be something like

+         && (!gfc_buffered_p () || !gfc_error_flag_test ()))

Namely:
* If there is no buffering, we know that no error has been printed → call error.
* With buffering, we additionally need to check for buffered errors.
   No buffered error → call error.

Otherwise LGTM.

Thus, if my comment makes sense to you + it regtests, modify it, and
go ahead and commit it.

Sorry for the delay - and thanks again for the patch!

Tobias

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