[PATCH] PR fortran/102685 - ICE in output_constructor_regular_field, at varasm.c:5514

[PATCH] PR fortran/102685 - ICE in output_constructor_regular_field, at varasm.c:5514

[Harald Anlauf]

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Dear Fortranners,

the attached patch adds a check for the shape of arrays in derived type
constructors.  This brings it in line with other major brands.

Example:

  type t
     integer :: a(1)
  end type
  type(t), parameter :: y(2) = t([1,2])
end

This was silently accepted before, but now gives:

pr102685-z1.f90:4:33:

    4 |   type(t), parameter :: y(2) = t([1,2])
      |                                 1
Error: The shape of component 'a' in the structure constructor at (1) differs from the shape of the declared component for dimension 1 (2/1)

During regtesting several previously invalid testcases surfaced
which would be rejected by the present change.  They have been
adjusted along the discussion with Tobias and Paul, see the thread

https://gcc.gnu.org/pipermail/fortran/2021-October/056707.html

In developing the patch I encountered a difficulty with testcase
dec_structure_6.f90, which uses a DEC extension, namelist "old-style
CLIST initializers in STRUCTURE".  I could not figure out how to
determine the shape of the initializer; it seemed to be always zero.
I've added code to accept this, but only under -fdec-structure, and
added a TODO in a comment.  If somebody reading this could give me
a hint to solve end, I would adjust the patch accordingly.

Regtested on x86_64-pc-linux-gnu.  OK?  Or further comments?

Thanks,
Harald


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Fortran: validate shape of arrays in constructors against declarations

gcc/fortran/ChangeLog:

	PR fortran/102685
	* resolve.c (resolve_structure_cons): In a structure constructor,
	compare shapes of array components against declared shape.

gcc/testsuite/ChangeLog:

	PR fortran/102685
	* gfortran.dg/derived_constructor_char_1.f90: Fix invalid code.
	* gfortran.dg/pr70931.f90: Likewise.
	* gfortran.dg/transfer_simplify_2.f90: Likewise.
	* gfortran.dg/pr102685.f90: New test.

diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c
index 0d0af39d23f..d035b30ad7d 100644
--- a/gcc/fortran/resolve.c
+++ b/gcc/fortran/resolve.c
@@ -29,6 +29,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "data.h"
 #include "target-memory.h" /* for gfc_simplify_transfer */
 #include "constructor.h"
+#include "parse.h"

 /* Types used in equivalence statements.  */

@@ -1454,6 +1455,42 @@ resolve_structure_cons (gfc_expr *expr, int init)
 	    }
 	}

+      /* Validate shape.  We silently accept some cases where the apparent
+	 shape of the constructor is zero, and we cannot check dynamic or PDT
+	 arrays.  */
+      if (cons->expr->expr_type == EXPR_ARRAY && rank == cons->expr->rank
+	  && comp->as && !comp->attr.allocatable && !comp->attr.pointer
+	  && !comp->attr.pdt_array)
+	{
+	  mpz_t len;
+	  mpz_init (len);
+	  for (int n = 0; n < rank; n++)
+	    {
+	      gcc_assert (comp->as->upper[n]->expr_type == EXPR_CONSTANT
+			  && comp->as->lower[n]->expr_type == EXPR_CONSTANT);
+	      mpz_set_ui (len, 1);
+	      mpz_add (len, len, comp->as->upper[n]->value.integer);
+	      mpz_sub (len, len, comp->as->lower[n]->value.integer);
+	      /* Shape agrees for this dimension.  */
+	      if (mpz_cmp (cons->expr->shape[n], len) == 0)
+		continue;
+	      /* Accept DEC old-style initializers in STRUCTURE, where shape
+		 is currently not correctly set (it is zero.  Why?).
+		 TODO: Fix this or find a better solution.  */
+	      if (flag_dec_structure
+		  && mpz_cmp_si (cons->expr->shape[n], 0) == 0)
+		continue;
+	      gfc_error ("The shape of component %qs in the structure "
+			 "constructor at %L differs from the shape of the "
+			 "declared component for dimension %d (%ld/%ld)",
+			 comp->name, &cons->expr->where, n+1,
+			 mpz_get_si (cons->expr->shape[n]),
+			 mpz_get_si (len));
+	      t = false;
+	    }
+	  mpz_clear (len);
+	}
+
       if (!comp->attr.pointer || comp->attr.proc_pointer
 	  || cons->expr->expr_type == EXPR_NULL)
 	continue;
diff --git a/gcc/testsuite/gfortran.dg/derived_constructor_char_1.f90 b/gcc/testsuite/gfortran.dg/derived_constructor_char_1.f90
index 892a9c9f4c1..91fc4c902d8 100644
--- a/gcc/testsuite/gfortran.dg/derived_constructor_char_1.f90
+++ b/gcc/testsuite/gfortran.dg/derived_constructor_char_1.f90
@@ -5,7 +5,7 @@
 !
 !
   Type :: t5
-    character (len=5) :: txt(4)
+    character (len=5) :: txt(2)
   End Type t5

   character (len=3), parameter :: str3(2) = [ "ABC", "ZYX" ]
diff --git a/gcc/testsuite/gfortran.dg/pr102685.f90 b/gcc/testsuite/gfortran.dg/pr102685.f90
new file mode 100644
index 00000000000..d325c27b32a
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr102685.f90
@@ -0,0 +1,30 @@
+! { dg-do compile }
+! PR fortran/102685
+
+program p
+  type t
+     integer :: a(2)
+  end type
+  type(t), parameter :: x0    = t([2])         ! { dg-error "shape of component" }
+  type(t), parameter :: x1(2) = t([2])         ! { dg-error "shape of component" }
+  type(t), parameter :: x(2)  = t([integer::]) ! { dg-error "shape of component" }
+
+  type u
+     integer :: a
+     integer :: b(0)
+  end type
+  type(u), parameter :: z0(2) = u(1, [integer::]) ! valid
+  type(u), parameter :: z1    = u(1,  2 )         ! valid
+  type(u), parameter :: z2(2) = u(1,  2 )         ! valid
+  type(u), parameter :: z3    = u(1, [2])         ! { dg-error "shape of component" }
+  type(u), parameter :: z4(2) = u(1, [2])         ! { dg-error "shape of component" }
+
+  type v
+     integer :: a(2,1)
+  end type
+  type(v), parameter :: y0   = v(reshape([1,2],[2,1])) ! valid
+  type(v), parameter :: y1   = v(reshape([1,2],[1,2])) ! { dg-error "shape of component" }
+  type(v), parameter :: y(1) = v(reshape([1,2],[1,2])) ! { dg-error "shape of component" }
+
+  print *, x0,x,x1,y0,y1,y,z0,z1,z2,z3,z4
+end
diff --git a/gcc/testsuite/gfortran.dg/pr70931.f90 b/gcc/testsuite/gfortran.dg/pr70931.f90
index 08ecd687752..4444b5eec3b 100644
--- a/gcc/testsuite/gfortran.dg/pr70931.f90
+++ b/gcc/testsuite/gfortran.dg/pr70931.f90
@@ -5,6 +5,7 @@ program p
       integer :: a
       integer :: b(0)
    end type
-   type(t), parameter :: z = t(1, [2])
+!  type(t), parameter :: z = t(1, [2])         ! original invalid code
+   type(t), parameter :: z = t(1, [integer::])
    print *, z
 end
diff --git a/gcc/testsuite/gfortran.dg/transfer_simplify_2.f90 b/gcc/testsuite/gfortran.dg/transfer_simplify_2.f90
index e0f3f94c4ca..b428fa64b56 100644
--- a/gcc/testsuite/gfortran.dg/transfer_simplify_2.f90
+++ b/gcc/testsuite/gfortran.dg/transfer_simplify_2.f90
@@ -145,7 +145,7 @@ contains
       real(4) :: x(2)
     end type mytype

-    type (mytype), parameter :: dt1(2) = transfer (c1, mytype ((/1.0,2.0,3.0,4.0/)), 2)
+    type (mytype), parameter :: dt1(2) = transfer (c1, mytype ((/1.0,2.0/)), 2)
     type (mytype)            :: dt2(2)

     dt2 = transfer (c2, dt2);

Re: [PATCH] PR fortran/102685 - ICE in output_constructor_regular_field, at varasm.c:5514

[Tobias Burnus]

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Hi Harald, dear all,

On 14.10.21 23:27, Harald Anlauf via Fortran wrote:
> the attached patch adds a check for the shape of arrays in derived type
> constructors.  This brings it in line with other major brands.
> ...
> In developing the patch I encountered a difficulty with testcase
> dec_structure_6.f90, which uses a DEC extension, namelist "old-style
> CLIST initializers in STRUCTURE".  I could not figure out how to
> determine the shape of the initializer; it seemed to be always zero.
> I've added code to accept this, but only under -fdec-structure, and
> added a TODO in a comment.  If somebody reading this could give me
> a hint to solve end, I would adjust the patch accordingly.

See attached patch – it does initialize the variables similarly to other
shapes in that file, except that it has to take the shape from the LHS
as seemingly (same testfile) having a 1-dim array can be used to
initialize a 2-dim array.

You can approve that patch and integrate it then in your own patch :-)

> Regtested on x86_64-pc-linux-gnu.  OK?  Or further comments?

LGTM – with the DECL exception removed from resolve.c.

Thanks,

Tobias

PS: Without the auto-reshape part, a simple 'gfc_array_size (expr,
&expr->shape[0]))" would have been sufficient.
-----------------
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diff --git a/gcc/fortran/decl.c b/gcc/fortran/decl.c
index d6a22d13451..86adb81da32 100644
--- a/gcc/fortran/decl.c
+++ b/gcc/fortran/decl.c
@@ -892,29 +892,32 @@ match_clist_expr (gfc_expr **result, gfc_typespec *ts, gfc_array_spec *as)
   /* Set up expr as an array constructor. */
   if (!scalar)
     {
       expr = gfc_get_array_expr (ts->type, ts->kind, &where);
       expr->ts = *ts;
       expr->value.constructor = array_head;
 
-      expr->rank = as->rank;
-      expr->shape = gfc_get_shape (expr->rank);
-
       /* Validate sizes.  We built expr ourselves, so cons_size will be
 	 constant (we fail above for non-constant expressions).
 	 We still need to verify that the sizes match.  */
       gcc_assert (gfc_array_size (expr, &cons_size));
       cmp = mpz_cmp (cons_size, as_size);
       if (cmp < 0)
 	gfc_error ("Not enough elements in array initializer at %C");
       else if (cmp > 0)
 	gfc_error ("Too many elements in array initializer at %C");
       mpz_clear (cons_size);
       if (cmp)
 	goto cleanup;
+
+      /* Set the rank/shape to match the LHS as auto-reshape is implied. */
+      expr->rank = as->rank;
+      expr->shape = gfc_get_shape (as->rank);
+      for (int i = 0; i < as->rank; ++i)
+	spec_dimen_size (as, i, &expr->shape[i]);
     }
 
   /* Make sure scalar types match. */
   else if (!gfc_compare_types (&expr->ts, ts)
            && !gfc_convert_type (expr, ts, 1))
     goto cleanup;
 

Re: [PATCH] PR fortran/102685 - ICE in output_constructor_regular_field, at varasm.c:5514

[Harald Anlauf]

Hi Tobias, all,

> > In developing the patch I encountered a difficulty with testcase
> > dec_structure_6.f90, which uses a DEC extension, namelist "old-style
> > CLIST initializers in STRUCTURE".  I could not figure out how to
> > determine the shape of the initializer; it seemed to be always zero.
> > I've added code to accept this, but only under -fdec-structure, and
> > added a TODO in a comment.  If somebody reading this could give me
> > a hint to solve end, I would adjust the patch accordingly.
> 
> See attached patch – it does initialize the variables similarly to other
> shapes in that file, except that it has to take the shape from the LHS
> as seemingly (same testfile) having a 1-dim array can be used to
> initialize a 2-dim array.
> 
> You can approve that patch and integrate it then in your own patch :-)

your fix to match_clist_expr LGTM.  I can really use it.

> LGTM – with the DECL exception removed from resolve.c.

I've removed the DEC exception, cleaned up, regtested again.

Committed and pushed:

https://gcc.gnu.org/g:1e819bd95ebeefc1dc469daa1855ce005cb77822

Thanks,
Harald

> Thanks,
> 
> Tobias
> 
> PS: Without the auto-reshape part, a simple 'gfc_array_size (expr,
> &expr->shape[0]))" would have been sufficient.
> -----------------
> Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955
>