[PATCH] PR fortran/102717 - ICE in gfc_simplify_reshape, at fortran/simplify.c:6843

[Harald Anlauf via Gcc-patches]

Dear Fortranners,

when simplifying RESHAPE we hit a gcc_assert for negative entries in the
SHAPE array.  Obvious solution: replace gcc_assert by an error message.

Regtested on x86_64-pc-linux-gnu.  OK for mainline?

As this is a safe fix, I'd like to backport to suitable branches.

Thanks,
Harald


Fortran: generate error	message for negative elements in SHAPE array

gcc/fortran/ChangeLog:

	PR fortran/102717
	* simplify.c (gfc_simplify_reshape): Replace assert by error
	message for negative elements in SHAPE array.

gcc/testsuite/ChangeLog:

	PR fortran/102717
	* gfortran.dg/reshape_shape_2.f90: New test.

diff --git a/gcc/fortran/simplify.c b/gcc/fortran/simplify.c
index f40e4930b58..d675f2c3aef 100644
--- a/gcc/fortran/simplify.c
+++ b/gcc/fortran/simplify.c
@@ -6840,7 +6840,13 @@ gfc_simplify_reshape (gfc_expr *source, gfc_expr *shape_exp,
       gfc_extract_int (e, &shape[rank]);

       gcc_assert (rank >= 0 && rank < GFC_MAX_DIMENSIONS);
-      gcc_assert (shape[rank] >= 0);
+      if (shape[rank] < 0)
+	{
+	  gfc_error ("The SHAPE array for the RESHAPE intrinsic at %L has a "
+		     "negative value %d for dimension %d",
+		     &shape_exp->where, shape[rank], rank+1);
+	  return &gfc_bad_expr;
+	}

       rank++;
     }
diff --git a/gcc/testsuite/gfortran.dg/reshape_shape_2.f90 b/gcc/testsuite/gfortran.dg/reshape_shape_2.f90
new file mode 100644
index 00000000000..8f1757687bc
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/reshape_shape_2.f90
@@ -0,0 +1,7 @@
+! { dg-do compile }
+! PR fortran/102717
+
+program p
+  integer, parameter :: a(1) = 2
+  integer, parameter :: b(2) = reshape([3,4], -[a]) ! { dg-error "negative" }
+end