obtained gcc-4.6.4.tar.bz2 from upstream website;upstream

verified gcc-4.6.4.tar.bz2.sig;
imported gcc-4.6.4 source tree from verified upstream tarball.

downloading a git-generated archive based on the 'upstream' tag
should provide you with a source tree that is binary identical
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if you have obtained the source via the command 'git clone',
however, do note that line-endings of files in your working
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1 files changed, 4621 insertions, 0 deletions

diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
new file mode 100644
index 000000000..5fa937e85
--- /dev/null
+++ b/gcc/fortran/expr.c
@@ -0,0 +1,4621 @@
+/* Routines for manipulation of expression nodes.
+   Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
+   2009, 2010, 2011
+   Free Software Foundation, Inc.
+   Contributed by Andy Vaught
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "gfortran.h"
+#include "arith.h"
+#include "match.h"
+#include "target-memory.h" /* for gfc_convert_boz */
+#include "constructor.h"
+
+
+/* The following set of functions provide access to gfc_expr* of
+   various types - actual all but EXPR_FUNCTION and EXPR_VARIABLE.
+
+   There are two functions available elsewhere that provide
+   slightly different flavours of variables.  Namely:
+     expr.c (gfc_get_variable_expr)
+     symbol.c (gfc_lval_expr_from_sym)
+   TODO: Merge these functions, if possible.  */
+
+/* Get a new expression node.  */
+
+gfc_expr *
+gfc_get_expr (void)
+{
+  gfc_expr *e;
+
+  e = XCNEW (gfc_expr);
+  gfc_clear_ts (&e->ts);
+  e->shape = NULL;
+  e->ref = NULL;
+  e->symtree = NULL;
+  return e;
+}
+
+
+/* Get a new expression node that is an array constructor
+   of given type and kind.  */
+
+gfc_expr *
+gfc_get_array_expr (bt type, int kind, locus *where)
+{
+  gfc_expr *e;
+
+  e = gfc_get_expr ();
+  e->expr_type = EXPR_ARRAY;
+  e->value.constructor = NULL;
+  e->rank = 1;
+  e->shape = NULL;
+
+  e->ts.type = type;
+  e->ts.kind = kind;
+  if (where)
+    e->where = *where;
+
+  return e;
+}
+
+
+/* Get a new expression node that is the NULL expression.  */
+
+gfc_expr *
+gfc_get_null_expr (locus *where)
+{
+  gfc_expr *e;
+
+  e = gfc_get_expr ();
+  e->expr_type = EXPR_NULL;
+  e->ts.type = BT_UNKNOWN;
+
+  if (where)
+    e->where = *where;
+
+  return e;
+}
+
+
+/* Get a new expression node that is an operator expression node.  */
+
+gfc_expr *
+gfc_get_operator_expr (locus *where, gfc_intrinsic_op op,
+                      gfc_expr *op1, gfc_expr *op2)
+{
+  gfc_expr *e;
+
+  e = gfc_get_expr ();
+  e->expr_type = EXPR_OP;
+  e->value.op.op = op;
+  e->value.op.op1 = op1;
+  e->value.op.op2 = op2;
+
+  if (where)
+    e->where = *where;
+
+  return e;
+}
+
+
+/* Get a new expression node that is an structure constructor
+   of given type and kind.  */
+
+gfc_expr *
+gfc_get_structure_constructor_expr (bt type, int kind, locus *where)
+{
+  gfc_expr *e;
+
+  e = gfc_get_expr ();
+  e->expr_type = EXPR_STRUCTURE;
+  e->value.constructor = NULL;
+
+  e->ts.type = type;
+  e->ts.kind = kind;
+  if (where)
+    e->where = *where;
+
+  return e;
+}
+
+
+/* Get a new expression node that is an constant of given type and kind.  */
+
+gfc_expr *
+gfc_get_constant_expr (bt type, int kind, locus *where)
+{
+  gfc_expr *e;
+
+  if (!where)
+    gfc_internal_error ("gfc_get_constant_expr(): locus 'where' cannot be NULL");
+
+  e = gfc_get_expr ();
+
+  e->expr_type = EXPR_CONSTANT;
+  e->ts.type = type;
+  e->ts.kind = kind;
+  e->where = *where;
+
+  switch (type)
+    {
+    case BT_INTEGER:
+      mpz_init (e->value.integer);
+      break;
+
+    case BT_REAL:
+      gfc_set_model_kind (kind);
+      mpfr_init (e->value.real);
+      break;
+
+    case BT_COMPLEX:
+      gfc_set_model_kind (kind);
+      mpc_init2 (e->value.complex, mpfr_get_default_prec());
+      break;
+
+    default:
+      break;
+    }
+
+  return e;
+}
+
+
+/* Get a new expression node that is an string constant.
+   If no string is passed, a string of len is allocated,
+   blanked and null-terminated.  */
+
+gfc_expr *
+gfc_get_character_expr (int kind, locus *where, const char *src, int len)
+{
+  gfc_expr *e;
+  gfc_char_t *dest;
+
+  if (!src)
+    {
+      dest = gfc_get_wide_string (len + 1);
+      gfc_wide_memset (dest, ' ', len);
+      dest[len] = '\0';
+    }
+  else
+    dest = gfc_char_to_widechar (src);
+
+  e = gfc_get_constant_expr (BT_CHARACTER, kind,
+                            where ? where : &gfc_current_locus);
+  e->value.character.string = dest;
+  e->value.character.length = len;
+
+  return e;
+}
+
+
+/* Get a new expression node that is an integer constant.  */
+
+gfc_expr *
+gfc_get_int_expr (int kind, locus *where, int value)
+{
+  gfc_expr *p;
+  p = gfc_get_constant_expr (BT_INTEGER, kind,
+			     where ? where : &gfc_current_locus);
+
+  mpz_set_si (p->value.integer, value);
+
+  return p;
+}
+
+
+/* Get a new expression node that is a logical constant.  */
+
+gfc_expr *
+gfc_get_logical_expr (int kind, locus *where, bool value)
+{
+  gfc_expr *p;
+  p = gfc_get_constant_expr (BT_LOGICAL, kind,
+			     where ? where : &gfc_current_locus);
+
+  p->value.logical = value;
+
+  return p;
+}
+
+
+gfc_expr *
+gfc_get_iokind_expr (locus *where, io_kind k)
+{
+  gfc_expr *e;
+
+  /* Set the types to something compatible with iokind. This is needed to
+     get through gfc_free_expr later since iokind really has no Basic Type,
+     BT, of its own.  */
+
+  e = gfc_get_expr ();
+  e->expr_type = EXPR_CONSTANT;
+  e->ts.type = BT_LOGICAL;
+  e->value.iokind = k;
+  e->where = *where;
+
+  return e;
+}
+
+
+/* Given an expression pointer, return a copy of the expression.  This
+   subroutine is recursive.  */
+
+gfc_expr *
+gfc_copy_expr (gfc_expr *p)
+{
+  gfc_expr *q;
+  gfc_char_t *s;
+  char *c;
+
+  if (p == NULL)
+    return NULL;
+
+  q = gfc_get_expr ();
+  *q = *p;
+
+  switch (q->expr_type)
+    {
+    case EXPR_SUBSTRING:
+      s = gfc_get_wide_string (p->value.character.length + 1);
+      q->value.character.string = s;
+      memcpy (s, p->value.character.string,
+	      (p->value.character.length + 1) * sizeof (gfc_char_t));
+      break;
+
+    case EXPR_CONSTANT:
+      /* Copy target representation, if it exists.  */
+      if (p->representation.string)
+	{
+	  c = XCNEWVEC (char, p->representation.length + 1);
+	  q->representation.string = c;
+	  memcpy (c, p->representation.string, (p->representation.length + 1));
+	}
+
+      /* Copy the values of any pointer components of p->value.  */
+      switch (q->ts.type)
+	{
+	case BT_INTEGER:
+	  mpz_init_set (q->value.integer, p->value.integer);
+	  break;
+
+	case BT_REAL:
+	  gfc_set_model_kind (q->ts.kind);
+	  mpfr_init (q->value.real);
+	  mpfr_set (q->value.real, p->value.real, GFC_RND_MODE);
+	  break;
+
+	case BT_COMPLEX:
+	  gfc_set_model_kind (q->ts.kind);
+	  mpc_init2 (q->value.complex, mpfr_get_default_prec());
+	  mpc_set (q->value.complex, p->value.complex, GFC_MPC_RND_MODE);
+	  break;
+
+	case BT_CHARACTER:
+	  if (p->representation.string)
+	    q->value.character.string
+	      = gfc_char_to_widechar (q->representation.string);
+	  else
+	    {
+	      s = gfc_get_wide_string (p->value.character.length + 1);
+	      q->value.character.string = s;
+
+	      /* This is the case for the C_NULL_CHAR named constant.  */
+	      if (p->value.character.length == 0
+		  && (p->ts.is_c_interop || p->ts.is_iso_c))
+		{
+		  *s = '\0';
+		  /* Need to set the length to 1 to make sure the NUL
+		     terminator is copied.  */
+		  q->value.character.length = 1;
+		}
+	      else
+		memcpy (s, p->value.character.string,
+			(p->value.character.length + 1) * sizeof (gfc_char_t));
+	    }
+	  break;
+
+	case BT_HOLLERITH:
+	case BT_LOGICAL:
+	case BT_DERIVED:
+	case BT_CLASS:
+	  break;		/* Already done.  */
+
+	case BT_PROCEDURE:
+        case BT_VOID:
+           /* Should never be reached.  */
+	case BT_UNKNOWN:
+	  gfc_internal_error ("gfc_copy_expr(): Bad expr node");
+	  /* Not reached.  */
+	}
+
+      break;
+
+    case EXPR_OP:
+      switch (q->value.op.op)
+	{
+	case INTRINSIC_NOT:
+	case INTRINSIC_PARENTHESES:
+	case INTRINSIC_UPLUS:
+	case INTRINSIC_UMINUS:
+	  q->value.op.op1 = gfc_copy_expr (p->value.op.op1);
+	  break;
+
+	default:		/* Binary operators.  */
+	  q->value.op.op1 = gfc_copy_expr (p->value.op.op1);
+	  q->value.op.op2 = gfc_copy_expr (p->value.op.op2);
+	  break;
+	}
+
+      break;
+
+    case EXPR_FUNCTION:
+      q->value.function.actual =
+	gfc_copy_actual_arglist (p->value.function.actual);
+      break;
+
+    case EXPR_COMPCALL:
+    case EXPR_PPC:
+      q->value.compcall.actual =
+	gfc_copy_actual_arglist (p->value.compcall.actual);
+      q->value.compcall.tbp = p->value.compcall.tbp;
+      break;
+
+    case EXPR_STRUCTURE:
+    case EXPR_ARRAY:
+      q->value.constructor = gfc_constructor_copy (p->value.constructor);
+      break;
+
+    case EXPR_VARIABLE:
+    case EXPR_NULL:
+      break;
+    }
+
+  q->shape = gfc_copy_shape (p->shape, p->rank);
+
+  q->ref = gfc_copy_ref (p->ref);
+
+  return q;
+}
+
+
+void
+gfc_clear_shape (mpz_t *shape, int rank)
+{
+  int i;
+
+  for (i = 0; i < rank; i++)
+    mpz_clear (shape[i]);
+}
+
+
+void
+gfc_free_shape (mpz_t **shape, int rank)
+{
+  if (*shape == NULL)
+    return;
+
+  gfc_clear_shape (*shape, rank);
+  gfc_free (*shape);
+  *shape = NULL;
+}
+
+
+/* Workhorse function for gfc_free_expr() that frees everything
+   beneath an expression node, but not the node itself.  This is
+   useful when we want to simplify a node and replace it with
+   something else or the expression node belongs to another structure.  */
+
+static void
+free_expr0 (gfc_expr *e)
+{
+  switch (e->expr_type)
+    {
+    case EXPR_CONSTANT:
+      /* Free any parts of the value that need freeing.  */
+      switch (e->ts.type)
+	{
+	case BT_INTEGER:
+	  mpz_clear (e->value.integer);
+	  break;
+
+	case BT_REAL:
+	  mpfr_clear (e->value.real);
+	  break;
+
+	case BT_CHARACTER:
+	  gfc_free (e->value.character.string);
+	  break;
+
+	case BT_COMPLEX:
+	  mpc_clear (e->value.complex);
+	  break;
+
+	default:
+	  break;
+	}
+
+      /* Free the representation.  */
+      if (e->representation.string)
+	gfc_free (e->representation.string);
+
+      break;
+
+    case EXPR_OP:
+      if (e->value.op.op1 != NULL)
+	gfc_free_expr (e->value.op.op1);
+      if (e->value.op.op2 != NULL)
+	gfc_free_expr (e->value.op.op2);
+      break;
+
+    case EXPR_FUNCTION:
+      gfc_free_actual_arglist (e->value.function.actual);
+      break;
+
+    case EXPR_COMPCALL:
+    case EXPR_PPC:
+      gfc_free_actual_arglist (e->value.compcall.actual);
+      break;
+
+    case EXPR_VARIABLE:
+      break;
+
+    case EXPR_ARRAY:
+    case EXPR_STRUCTURE:
+      gfc_constructor_free (e->value.constructor);
+      break;
+
+    case EXPR_SUBSTRING:
+      gfc_free (e->value.character.string);
+      break;
+
+    case EXPR_NULL:
+      break;
+
+    default:
+      gfc_internal_error ("free_expr0(): Bad expr type");
+    }
+
+  /* Free a shape array.  */
+  gfc_free_shape (&e->shape, e->rank);
+
+  gfc_free_ref_list (e->ref);
+
+  memset (e, '\0', sizeof (gfc_expr));
+}
+
+
+/* Free an expression node and everything beneath it.  */
+
+void
+gfc_free_expr (gfc_expr *e)
+{
+  if (e == NULL)
+    return;
+  free_expr0 (e);
+  gfc_free (e);
+}
+
+
+/* Free an argument list and everything below it.  */
+
+void
+gfc_free_actual_arglist (gfc_actual_arglist *a1)
+{
+  gfc_actual_arglist *a2;
+
+  while (a1)
+    {
+      a2 = a1->next;
+      gfc_free_expr (a1->expr);
+      gfc_free (a1);
+      a1 = a2;
+    }
+}
+
+
+/* Copy an arglist structure and all of the arguments.  */
+
+gfc_actual_arglist *
+gfc_copy_actual_arglist (gfc_actual_arglist *p)
+{
+  gfc_actual_arglist *head, *tail, *new_arg;
+
+  head = tail = NULL;
+
+  for (; p; p = p->next)
+    {
+      new_arg = gfc_get_actual_arglist ();
+      *new_arg = *p;
+
+      new_arg->expr = gfc_copy_expr (p->expr);
+      new_arg->next = NULL;
+
+      if (head == NULL)
+	head = new_arg;
+      else
+	tail->next = new_arg;
+
+      tail = new_arg;
+    }
+
+  return head;
+}
+
+
+/* Free a list of reference structures.  */
+
+void
+gfc_free_ref_list (gfc_ref *p)
+{
+  gfc_ref *q;
+  int i;
+
+  for (; p; p = q)
+    {
+      q = p->next;
+
+      switch (p->type)
+	{
+	case REF_ARRAY:
+	  for (i = 0; i < GFC_MAX_DIMENSIONS; i++)
+	    {
+	      gfc_free_expr (p->u.ar.start[i]);
+	      gfc_free_expr (p->u.ar.end[i]);
+	      gfc_free_expr (p->u.ar.stride[i]);
+	    }
+
+	  break;
+
+	case REF_SUBSTRING:
+	  gfc_free_expr (p->u.ss.start);
+	  gfc_free_expr (p->u.ss.end);
+	  break;
+
+	case REF_COMPONENT:
+	  break;
+	}
+
+      gfc_free (p);
+    }
+}
+
+
+/* Graft the *src expression onto the *dest subexpression.  */
+
+void
+gfc_replace_expr (gfc_expr *dest, gfc_expr *src)
+{
+  free_expr0 (dest);
+  *dest = *src;
+  gfc_free (src);
+}
+
+
+/* Try to extract an integer constant from the passed expression node.
+   Returns an error message or NULL if the result is set.  It is
+   tempting to generate an error and return SUCCESS or FAILURE, but
+   failure is OK for some callers.  */
+
+const char *
+gfc_extract_int (gfc_expr *expr, int *result)
+{
+  if (expr->expr_type != EXPR_CONSTANT)
+    return _("Constant expression required at %C");
+
+  if (expr->ts.type != BT_INTEGER)
+    return _("Integer expression required at %C");
+
+  if ((mpz_cmp_si (expr->value.integer, INT_MAX) > 0)
+      || (mpz_cmp_si (expr->value.integer, INT_MIN) < 0))
+    {
+      return _("Integer value too large in expression at %C");
+    }
+
+  *result = (int) mpz_get_si (expr->value.integer);
+
+  return NULL;
+}
+
+
+/* Recursively copy a list of reference structures.  */
+
+gfc_ref *
+gfc_copy_ref (gfc_ref *src)
+{
+  gfc_array_ref *ar;
+  gfc_ref *dest;
+
+  if (src == NULL)
+    return NULL;
+
+  dest = gfc_get_ref ();
+  dest->type = src->type;
+
+  switch (src->type)
+    {
+    case REF_ARRAY:
+      ar = gfc_copy_array_ref (&src->u.ar);
+      dest->u.ar = *ar;
+      gfc_free (ar);
+      break;
+
+    case REF_COMPONENT:
+      dest->u.c = src->u.c;
+      break;
+
+    case REF_SUBSTRING:
+      dest->u.ss = src->u.ss;
+      dest->u.ss.start = gfc_copy_expr (src->u.ss.start);
+      dest->u.ss.end = gfc_copy_expr (src->u.ss.end);
+      break;
+    }
+
+  dest->next = gfc_copy_ref (src->next);
+
+  return dest;
+}
+
+
+/* Detect whether an expression has any vector index array references.  */
+
+int
+gfc_has_vector_index (gfc_expr *e)
+{
+  gfc_ref *ref;
+  int i;
+  for (ref = e->ref; ref; ref = ref->next)
+    if (ref->type == REF_ARRAY)
+      for (i = 0; i < ref->u.ar.dimen; i++)
+	if (ref->u.ar.dimen_type[i] == DIMEN_VECTOR)
+	  return 1;
+  return 0;
+}
+
+
+/* Copy a shape array.  */
+
+mpz_t *
+gfc_copy_shape (mpz_t *shape, int rank)
+{
+  mpz_t *new_shape;
+  int n;
+
+  if (shape == NULL)
+    return NULL;
+
+  new_shape = gfc_get_shape (rank);
+
+  for (n = 0; n < rank; n++)
+    mpz_init_set (new_shape[n], shape[n]);
+
+  return new_shape;
+}
+
+
+/* Copy a shape array excluding dimension N, where N is an integer
+   constant expression.  Dimensions are numbered in fortran style --
+   starting with ONE.
+
+   So, if the original shape array contains R elements
+      { s1 ... sN-1  sN  sN+1 ... sR-1 sR}
+   the result contains R-1 elements:
+      { s1 ... sN-1  sN+1    ...  sR-1}
+
+   If anything goes wrong -- N is not a constant, its value is out
+   of range -- or anything else, just returns NULL.  */
+
+mpz_t *
+gfc_copy_shape_excluding (mpz_t *shape, int rank, gfc_expr *dim)
+{
+  mpz_t *new_shape, *s;
+  int i, n;
+
+  if (shape == NULL 
+      || rank <= 1
+      || dim == NULL
+      || dim->expr_type != EXPR_CONSTANT 
+      || dim->ts.type != BT_INTEGER)
+    return NULL;
+
+  n = mpz_get_si (dim->value.integer);
+  n--; /* Convert to zero based index.  */
+  if (n < 0 || n >= rank)
+    return NULL;
+
+  s = new_shape = gfc_get_shape (rank - 1);
+
+  for (i = 0; i < rank; i++)
+    {
+      if (i == n)
+	continue;
+      mpz_init_set (*s, shape[i]);
+      s++;
+    }
+
+  return new_shape;
+}
+
+
+/* Return the maximum kind of two expressions.  In general, higher
+   kind numbers mean more precision for numeric types.  */
+
+int
+gfc_kind_max (gfc_expr *e1, gfc_expr *e2)
+{
+  return (e1->ts.kind > e2->ts.kind) ? e1->ts.kind : e2->ts.kind;
+}
+
+
+/* Returns nonzero if the type is numeric, zero otherwise.  */
+
+static int
+numeric_type (bt type)
+{
+  return type == BT_COMPLEX || type == BT_REAL || type == BT_INTEGER;
+}
+
+
+/* Returns nonzero if the typespec is a numeric type, zero otherwise.  */
+
+int
+gfc_numeric_ts (gfc_typespec *ts)
+{
+  return numeric_type (ts->type);
+}
+
+
+/* Return an expression node with an optional argument list attached.
+   A variable number of gfc_expr pointers are strung together in an
+   argument list with a NULL pointer terminating the list.  */
+
+gfc_expr *
+gfc_build_conversion (gfc_expr *e)
+{
+  gfc_expr *p;
+
+  p = gfc_get_expr ();
+  p->expr_type = EXPR_FUNCTION;
+  p->symtree = NULL;
+  p->value.function.actual = NULL;
+
+  p->value.function.actual = gfc_get_actual_arglist ();
+  p->value.function.actual->expr = e;
+
+  return p;
+}
+
+
+/* Given an expression node with some sort of numeric binary
+   expression, insert type conversions required to make the operands
+   have the same type. Conversion warnings are disabled if wconversion
+   is set to 0.
+
+   The exception is that the operands of an exponential don't have to
+   have the same type.  If possible, the base is promoted to the type
+   of the exponent.  For example, 1**2.3 becomes 1.0**2.3, but
+   1.0**2 stays as it is.  */
+
+void
+gfc_type_convert_binary (gfc_expr *e, int wconversion)
+{
+  gfc_expr *op1, *op2;
+
+  op1 = e->value.op.op1;
+  op2 = e->value.op.op2;
+
+  if (op1->ts.type == BT_UNKNOWN || op2->ts.type == BT_UNKNOWN)
+    {
+      gfc_clear_ts (&e->ts);
+      return;
+    }
+
+  /* Kind conversions of same type.  */
+  if (op1->ts.type == op2->ts.type)
+    {
+      if (op1->ts.kind == op2->ts.kind)
+	{
+	  /* No type conversions.  */
+	  e->ts = op1->ts;
+	  goto done;
+	}
+
+      if (op1->ts.kind > op2->ts.kind)
+	gfc_convert_type_warn (op2, &op1->ts, 2, wconversion);
+      else
+	gfc_convert_type_warn (op1, &op2->ts, 2, wconversion);
+
+      e->ts = op1->ts;
+      goto done;
+    }
+
+  /* Integer combined with real or complex.  */
+  if (op2->ts.type == BT_INTEGER)
+    {
+      e->ts = op1->ts;
+
+      /* Special case for ** operator.  */
+      if (e->value.op.op == INTRINSIC_POWER)
+	goto done;
+
+      gfc_convert_type_warn (e->value.op.op2, &e->ts, 2, wconversion);
+      goto done;
+    }
+
+  if (op1->ts.type == BT_INTEGER)
+    {
+      e->ts = op2->ts;
+      gfc_convert_type_warn (e->value.op.op1, &e->ts, 2, wconversion);
+      goto done;
+    }
+
+  /* Real combined with complex.  */
+  e->ts.type = BT_COMPLEX;
+  if (op1->ts.kind > op2->ts.kind)
+    e->ts.kind = op1->ts.kind;
+  else
+    e->ts.kind = op2->ts.kind;
+  if (op1->ts.type != BT_COMPLEX || op1->ts.kind != e->ts.kind)
+    gfc_convert_type_warn (e->value.op.op1, &e->ts, 2, wconversion);
+  if (op2->ts.type != BT_COMPLEX || op2->ts.kind != e->ts.kind)
+    gfc_convert_type_warn (e->value.op.op2, &e->ts, 2, wconversion);
+
+done:
+  return;
+}
+
+
+/* Function to determine if an expression is constant or not.  This
+   function expects that the expression has already been simplified.  */
+
+int
+gfc_is_constant_expr (gfc_expr *e)
+{
+  gfc_constructor *c;
+  gfc_actual_arglist *arg;
+  gfc_symbol *sym;
+
+  if (e == NULL)
+    return 1;
+
+  switch (e->expr_type)
+    {
+    case EXPR_OP:
+      return (gfc_is_constant_expr (e->value.op.op1)
+	      && (e->value.op.op2 == NULL
+		  || gfc_is_constant_expr (e->value.op.op2)));
+
+    case EXPR_VARIABLE:
+      return 0;
+
+    case EXPR_FUNCTION:
+    case EXPR_PPC:
+    case EXPR_COMPCALL:
+      gcc_assert (e->symtree || e->value.function.esym
+		  || e->value.function.isym);
+
+      /* Call to intrinsic with at least one argument.  */
+      if (e->value.function.isym && e->value.function.actual)
+	{
+	  for (arg = e->value.function.actual; arg; arg = arg->next)
+	    if (!gfc_is_constant_expr (arg->expr))
+	      return 0;
+	}
+
+      /* Specification functions are constant.  */
+      /* F95, 7.1.6.2; F2003, 7.1.7  */
+      sym = NULL;
+      if (e->symtree)
+	sym = e->symtree->n.sym;
+      if (e->value.function.esym)
+	sym = e->value.function.esym;
+
+      if (sym
+	  && sym->attr.function
+	  && sym->attr.pure
+	  && !sym->attr.intrinsic
+	  && !sym->attr.recursive
+	  && sym->attr.proc != PROC_INTERNAL
+	  && sym->attr.proc != PROC_ST_FUNCTION
+	  && sym->attr.proc != PROC_UNKNOWN
+	  && sym->formal == NULL)
+	return 1;
+
+      if (e->value.function.isym
+	  && (e->value.function.isym->elemental
+	      || e->value.function.isym->pure
+	      || e->value.function.isym->inquiry
+	      || e->value.function.isym->transformational))
+	return 1;
+
+      return 0;
+
+    case EXPR_CONSTANT:
+    case EXPR_NULL:
+      return 1;
+
+    case EXPR_SUBSTRING:
+      return e->ref == NULL || (gfc_is_constant_expr (e->ref->u.ss.start)
+				&& gfc_is_constant_expr (e->ref->u.ss.end));
+
+    case EXPR_ARRAY:
+    case EXPR_STRUCTURE:
+      c = gfc_constructor_first (e->value.constructor);
+      if ((e->expr_type == EXPR_ARRAY) && c && c->iterator)
+        return gfc_constant_ac (e);
+
+      for (; c; c = gfc_constructor_next (c))
+	if (!gfc_is_constant_expr (c->expr))
+	  return 0;
+
+      return 1;
+
+
+    default:
+      gfc_internal_error ("gfc_is_constant_expr(): Unknown expression type");
+      return 0;
+    }
+}
+
+
+/* Is true if an array reference is followed by a component or substring
+   reference.  */
+bool
+is_subref_array (gfc_expr * e)
+{
+  gfc_ref * ref;
+  bool seen_array;
+
+  if (e->expr_type != EXPR_VARIABLE)
+    return false;
+
+  if (e->symtree->n.sym->attr.subref_array_pointer)
+    return true;
+
+  seen_array = false;
+  for (ref = e->ref; ref; ref = ref->next)
+    {
+      if (ref->type == REF_ARRAY
+	    && ref->u.ar.type != AR_ELEMENT)
+	seen_array = true;
+
+      if (seen_array
+	    && ref->type != REF_ARRAY)
+	return seen_array;
+    }
+  return false;
+}
+
+
+/* Try to collapse intrinsic expressions.  */
+
+static gfc_try
+simplify_intrinsic_op (gfc_expr *p, int type)
+{
+  gfc_intrinsic_op op;
+  gfc_expr *op1, *op2, *result;
+
+  if (p->value.op.op == INTRINSIC_USER)
+    return SUCCESS;
+
+  op1 = p->value.op.op1;
+  op2 = p->value.op.op2;
+  op  = p->value.op.op;
+
+  if (gfc_simplify_expr (op1, type) == FAILURE)
+    return FAILURE;
+  if (gfc_simplify_expr (op2, type) == FAILURE)
+    return FAILURE;
+
+  if (!gfc_is_constant_expr (op1)
+      || (op2 != NULL && !gfc_is_constant_expr (op2)))
+    return SUCCESS;
+
+  /* Rip p apart.  */
+  p->value.op.op1 = NULL;
+  p->value.op.op2 = NULL;
+
+  switch (op)
+    {
+    case INTRINSIC_PARENTHESES:
+      result = gfc_parentheses (op1);
+      break;
+
+    case INTRINSIC_UPLUS:
+      result = gfc_uplus (op1);
+      break;
+
+    case INTRINSIC_UMINUS:
+      result = gfc_uminus (op1);
+      break;
+
+    case INTRINSIC_PLUS:
+      result = gfc_add (op1, op2);
+      break;
+
+    case INTRINSIC_MINUS:
+      result = gfc_subtract (op1, op2);
+      break;
+
+    case INTRINSIC_TIMES:
+      result = gfc_multiply (op1, op2);
+      break;
+
+    case INTRINSIC_DIVIDE:
+      result = gfc_divide (op1, op2);
+      break;
+
+    case INTRINSIC_POWER:
+      result = gfc_power (op1, op2);
+      break;
+
+    case INTRINSIC_CONCAT:
+      result = gfc_concat (op1, op2);
+      break;
+
+    case INTRINSIC_EQ:
+    case INTRINSIC_EQ_OS:
+      result = gfc_eq (op1, op2, op);
+      break;
+
+    case INTRINSIC_NE:
+    case INTRINSIC_NE_OS:
+      result = gfc_ne (op1, op2, op);
+      break;
+
+    case INTRINSIC_GT:
+    case INTRINSIC_GT_OS:
+      result = gfc_gt (op1, op2, op);
+      break;
+
+    case INTRINSIC_GE:
+    case INTRINSIC_GE_OS:
+      result = gfc_ge (op1, op2, op);
+      break;
+
+    case INTRINSIC_LT:
+    case INTRINSIC_LT_OS:
+      result = gfc_lt (op1, op2, op);
+      break;
+
+    case INTRINSIC_LE:
+    case INTRINSIC_LE_OS:
+      result = gfc_le (op1, op2, op);
+      break;
+
+    case INTRINSIC_NOT:
+      result = gfc_not (op1);
+      break;
+
+    case INTRINSIC_AND:
+      result = gfc_and (op1, op2);
+      break;
+
+    case INTRINSIC_OR:
+      result = gfc_or (op1, op2);
+      break;
+
+    case INTRINSIC_EQV:
+      result = gfc_eqv (op1, op2);
+      break;
+
+    case INTRINSIC_NEQV:
+      result = gfc_neqv (op1, op2);
+      break;
+
+    default:
+      gfc_internal_error ("simplify_intrinsic_op(): Bad operator");
+    }
+
+  if (result == NULL)
+    {
+      gfc_free_expr (op1);
+      gfc_free_expr (op2);
+      return FAILURE;
+    }
+
+  result->rank = p->rank;
+  result->where = p->where;
+  gfc_replace_expr (p, result);
+
+  return SUCCESS;
+}
+
+
+/* Subroutine to simplify constructor expressions.  Mutually recursive
+   with gfc_simplify_expr().  */
+
+static gfc_try
+simplify_constructor (gfc_constructor_base base, int type)
+{
+  gfc_constructor *c;
+  gfc_expr *p;
+
+  for (c = gfc_constructor_first (base); c; c = gfc_constructor_next (c))
+    {
+      if (c->iterator
+	  && (gfc_simplify_expr (c->iterator->start, type) == FAILURE
+	      || gfc_simplify_expr (c->iterator->end, type) == FAILURE
+	      || gfc_simplify_expr (c->iterator->step, type) == FAILURE))
+	return FAILURE;
+
+      if (c->expr)
+	{
+	  /* Try and simplify a copy.  Replace the original if successful
+	     but keep going through the constructor at all costs.  Not
+	     doing so can make a dog's dinner of complicated things.  */
+	  p = gfc_copy_expr (c->expr);
+
+	  if (gfc_simplify_expr (p, type) == FAILURE)
+	    {
+	      gfc_free_expr (p);
+	      continue;
+	    }
+
+	  gfc_replace_expr (c->expr, p);
+	}
+    }
+
+  return SUCCESS;
+}
+
+
+/* Pull a single array element out of an array constructor.  */
+
+static gfc_try
+find_array_element (gfc_constructor_base base, gfc_array_ref *ar,
+		    gfc_constructor **rval)
+{
+  unsigned long nelemen;
+  int i;
+  mpz_t delta;
+  mpz_t offset;
+  mpz_t span;
+  mpz_t tmp;
+  gfc_constructor *cons;
+  gfc_expr *e;
+  gfc_try t;
+
+  t = SUCCESS;
+  e = NULL;
+
+  mpz_init_set_ui (offset, 0);
+  mpz_init (delta);
+  mpz_init (tmp);
+  mpz_init_set_ui (span, 1);
+  for (i = 0; i < ar->dimen; i++)
+    {
+      if (gfc_reduce_init_expr (ar->as->lower[i]) == FAILURE
+	  || gfc_reduce_init_expr (ar->as->upper[i]) == FAILURE)
+	{
+	  t = FAILURE;
+	  cons = NULL;
+	  goto depart;
+	}
+
+      e = gfc_copy_expr (ar->start[i]);
+      if (e->expr_type != EXPR_CONSTANT)
+	{
+	  cons = NULL;
+	  goto depart;
+	}
+
+      gcc_assert (ar->as->upper[i]->expr_type == EXPR_CONSTANT
+		  && ar->as->lower[i]->expr_type == EXPR_CONSTANT);
+
+      /* Check the bounds.  */
+      if ((ar->as->upper[i]
+	   && mpz_cmp (e->value.integer,
+		       ar->as->upper[i]->value.integer) > 0)
+	  || (mpz_cmp (e->value.integer,
+		       ar->as->lower[i]->value.integer) < 0))
+	{
+	  gfc_error ("Index in dimension %d is out of bounds "
+		     "at %L", i + 1, &ar->c_where[i]);
+	  cons = NULL;
+	  t = FAILURE;
+	  goto depart;
+	}
+
+      mpz_sub (delta, e->value.integer, ar->as->lower[i]->value.integer);
+      mpz_mul (delta, delta, span);
+      mpz_add (offset, offset, delta);
+
+      mpz_set_ui (tmp, 1);
+      mpz_add (tmp, tmp, ar->as->upper[i]->value.integer);
+      mpz_sub (tmp, tmp, ar->as->lower[i]->value.integer);
+      mpz_mul (span, span, tmp);
+    }
+
+  for (cons = gfc_constructor_first (base), nelemen = mpz_get_ui (offset);
+       cons && nelemen > 0; cons = gfc_constructor_next (cons), nelemen--)
+    {
+      if (cons->iterator)
+	{
+	  cons = NULL;
+	  goto depart;
+	}
+    }
+
+depart:
+  mpz_clear (delta);
+  mpz_clear (offset);
+  mpz_clear (span);
+  mpz_clear (tmp);
+  if (e)
+    gfc_free_expr (e);
+  *rval = cons;
+  return t;
+}
+
+
+/* Find a component of a structure constructor.  */
+
+static gfc_constructor *
+find_component_ref (gfc_constructor_base base, gfc_ref *ref)
+{
+  gfc_component *comp;
+  gfc_component *pick;
+  gfc_constructor *c = gfc_constructor_first (base);
+
+  comp = ref->u.c.sym->components;
+  pick = ref->u.c.component;
+  while (comp != pick)
+    {
+      comp = comp->next;
+      c = gfc_constructor_next (c);
+    }
+
+  return c;
+}
+
+
+/* Replace an expression with the contents of a constructor, removing
+   the subobject reference in the process.  */
+
+static void
+remove_subobject_ref (gfc_expr *p, gfc_constructor *cons)
+{
+  gfc_expr *e;
+
+  if (cons)
+    {
+      e = cons->expr;
+      cons->expr = NULL;
+    }
+  else
+    e = gfc_copy_expr (p);
+  e->ref = p->ref->next;
+  p->ref->next =  NULL;
+  gfc_replace_expr (p, e);
+}
+
+
+/* Pull an array section out of an array constructor.  */
+
+static gfc_try
+find_array_section (gfc_expr *expr, gfc_ref *ref)
+{
+  int idx;
+  int rank;
+  int d;
+  int shape_i;
+  int limit;
+  long unsigned one = 1;
+  bool incr_ctr;
+  mpz_t start[GFC_MAX_DIMENSIONS];
+  mpz_t end[GFC_MAX_DIMENSIONS];
+  mpz_t stride[GFC_MAX_DIMENSIONS];
+  mpz_t delta[GFC_MAX_DIMENSIONS];
+  mpz_t ctr[GFC_MAX_DIMENSIONS];
+  mpz_t delta_mpz;
+  mpz_t tmp_mpz;
+  mpz_t nelts;
+  mpz_t ptr;
+  gfc_constructor_base base;
+  gfc_constructor *cons, *vecsub[GFC_MAX_DIMENSIONS];
+  gfc_expr *begin;
+  gfc_expr *finish;
+  gfc_expr *step;
+  gfc_expr *upper;
+  gfc_expr *lower;
+  gfc_try t;
+
+  t = SUCCESS;
+
+  base = expr->value.constructor;
+  expr->value.constructor = NULL;
+
+  rank = ref->u.ar.as->rank;
+
+  if (expr->shape == NULL)
+    expr->shape = gfc_get_shape (rank);
+
+  mpz_init_set_ui (delta_mpz, one);
+  mpz_init_set_ui (nelts, one);
+  mpz_init (tmp_mpz);
+
+  /* Do the initialization now, so that we can cleanup without
+     keeping track of where we were.  */
+  for (d = 0; d < rank; d++)
+    {
+      mpz_init (delta[d]);
+      mpz_init (start[d]);
+      mpz_init (end[d]);
+      mpz_init (ctr[d]);
+      mpz_init (stride[d]);
+      vecsub[d] = NULL;
+    }
+
+  /* Build the counters to clock through the array reference.  */
+  shape_i = 0;
+  for (d = 0; d < rank; d++)
+    {
+      /* Make this stretch of code easier on the eye!  */
+      begin = ref->u.ar.start[d];
+      finish = ref->u.ar.end[d];
+      step = ref->u.ar.stride[d];
+      lower = ref->u.ar.as->lower[d];
+      upper = ref->u.ar.as->upper[d];
+
+      if (ref->u.ar.dimen_type[d] == DIMEN_VECTOR)  /* Vector subscript.  */
+	{
+	  gfc_constructor *ci;
+	  gcc_assert (begin);
+
+	  if (begin->expr_type != EXPR_ARRAY || !gfc_is_constant_expr (begin))
+	    {
+	      t = FAILURE;
+	      goto cleanup;
+	    }
+
+	  gcc_assert (begin->rank == 1);
+	  /* Zero-sized arrays have no shape and no elements, stop early.  */
+	  if (!begin->shape) 
+	    {
+	      mpz_init_set_ui (nelts, 0);
+	      break;
+	    }
+
+	  vecsub[d] = gfc_constructor_first (begin->value.constructor);
+	  mpz_set (ctr[d], vecsub[d]->expr->value.integer);
+	  mpz_mul (nelts, nelts, begin->shape[0]);
+	  mpz_set (expr->shape[shape_i++], begin->shape[0]);
+
+	  /* Check bounds.  */
+	  for (ci = vecsub[d]; ci; ci = gfc_constructor_next (ci))
+	    {
+	      if (mpz_cmp (ci->expr->value.integer, upper->value.integer) > 0
+		  || mpz_cmp (ci->expr->value.integer,
+			      lower->value.integer) < 0)
+		{
+		  gfc_error ("index in dimension %d is out of bounds "
+			     "at %L", d + 1, &ref->u.ar.c_where[d]);
+		  t = FAILURE;
+		  goto cleanup;
+		}
+	    }
+	}
+      else
+	{
+	  if ((begin && begin->expr_type != EXPR_CONSTANT)
+	      || (finish && finish->expr_type != EXPR_CONSTANT)
+	      || (step && step->expr_type != EXPR_CONSTANT))
+	    {
+	      t = FAILURE;
+	      goto cleanup;
+	    }
+
+	  /* Obtain the stride.  */
+	  if (step)
+	    mpz_set (stride[d], step->value.integer);
+	  else
+	    mpz_set_ui (stride[d], one);
+
+	  if (mpz_cmp_ui (stride[d], 0) == 0)
+	    mpz_set_ui (stride[d], one);
+
+	  /* Obtain the start value for the index.  */
+	  if (begin)
+	    mpz_set (start[d], begin->value.integer);
+	  else
+	    mpz_set (start[d], lower->value.integer);
+
+	  mpz_set (ctr[d], start[d]);
+
+	  /* Obtain the end value for the index.  */
+	  if (finish)
+	    mpz_set (end[d], finish->value.integer);
+	  else
+	    mpz_set (end[d], upper->value.integer);
+
+	  /* Separate 'if' because elements sometimes arrive with
+	     non-null end.  */
+	  if (ref->u.ar.dimen_type[d] == DIMEN_ELEMENT)
+	    mpz_set (end [d], begin->value.integer);
+
+	  /* Check the bounds.  */
+	  if (mpz_cmp (ctr[d], upper->value.integer) > 0
+	      || mpz_cmp (end[d], upper->value.integer) > 0
+	      || mpz_cmp (ctr[d], lower->value.integer) < 0
+	      || mpz_cmp (end[d], lower->value.integer) < 0)
+	    {
+	      gfc_error ("index in dimension %d is out of bounds "
+			 "at %L", d + 1, &ref->u.ar.c_where[d]);
+	      t = FAILURE;
+	      goto cleanup;
+	    }
+
+	  /* Calculate the number of elements and the shape.  */
+	  mpz_set (tmp_mpz, stride[d]);
+	  mpz_add (tmp_mpz, end[d], tmp_mpz);
+	  mpz_sub (tmp_mpz, tmp_mpz, ctr[d]);
+	  mpz_div (tmp_mpz, tmp_mpz, stride[d]);
+	  mpz_mul (nelts, nelts, tmp_mpz);
+
+	  /* An element reference reduces the rank of the expression; don't
+	     add anything to the shape array.  */
+	  if (ref->u.ar.dimen_type[d] != DIMEN_ELEMENT) 
+	    mpz_set (expr->shape[shape_i++], tmp_mpz);
+	}
+
+      /* Calculate the 'stride' (=delta) for conversion of the
+	 counter values into the index along the constructor.  */
+      mpz_set (delta[d], delta_mpz);
+      mpz_sub (tmp_mpz, upper->value.integer, lower->value.integer);
+      mpz_add_ui (tmp_mpz, tmp_mpz, one);
+      mpz_mul (delta_mpz, delta_mpz, tmp_mpz);
+    }
+
+  mpz_init (ptr);
+  cons = gfc_constructor_first (base);
+
+  /* Now clock through the array reference, calculating the index in
+     the source constructor and transferring the elements to the new
+     constructor.  */  
+  for (idx = 0; idx < (int) mpz_get_si (nelts); idx++)
+    {
+      if (ref->u.ar.offset)
+	mpz_set (ptr, ref->u.ar.offset->value.integer);
+      else
+	mpz_init_set_ui (ptr, 0);
+
+      incr_ctr = true;
+      for (d = 0; d < rank; d++)
+	{
+	  mpz_set (tmp_mpz, ctr[d]);
+	  mpz_sub (tmp_mpz, tmp_mpz, ref->u.ar.as->lower[d]->value.integer);
+	  mpz_mul (tmp_mpz, tmp_mpz, delta[d]);
+	  mpz_add (ptr, ptr, tmp_mpz);
+
+	  if (!incr_ctr) continue;
+
+	  if (ref->u.ar.dimen_type[d] == DIMEN_VECTOR) /* Vector subscript.  */
+	    {
+	      gcc_assert(vecsub[d]);
+
+	      if (!gfc_constructor_next (vecsub[d]))
+		vecsub[d] = gfc_constructor_first (ref->u.ar.start[d]->value.constructor);
+	      else
+		{
+		  vecsub[d] = gfc_constructor_next (vecsub[d]);
+		  incr_ctr = false;
+		}
+	      mpz_set (ctr[d], vecsub[d]->expr->value.integer);
+	    }
+	  else
+	    {
+	      mpz_add (ctr[d], ctr[d], stride[d]); 
+
+	      if (mpz_cmp_ui (stride[d], 0) > 0
+		  ? mpz_cmp (ctr[d], end[d]) > 0
+		  : mpz_cmp (ctr[d], end[d]) < 0)
+		mpz_set (ctr[d], start[d]);
+	      else
+		incr_ctr = false;
+	    }
+	}
+
+      limit = mpz_get_ui (ptr);
+      if (limit >= gfc_option.flag_max_array_constructor)
+        {
+	  gfc_error ("The number of elements in the array constructor "
+		     "at %L requires an increase of the allowed %d "
+		     "upper limit.   See -fmax-array-constructor "
+		     "option", &expr->where,
+		     gfc_option.flag_max_array_constructor);
+	  return FAILURE;
+	}
+
+      cons = gfc_constructor_lookup (base, limit);
+      gcc_assert (cons);
+      gfc_constructor_append_expr (&expr->value.constructor,
+				   gfc_copy_expr (cons->expr), NULL);
+    }
+
+  mpz_clear (ptr);
+
+cleanup:
+
+  mpz_clear (delta_mpz);
+  mpz_clear (tmp_mpz);
+  mpz_clear (nelts);
+  for (d = 0; d < rank; d++)
+    {
+      mpz_clear (delta[d]);
+      mpz_clear (start[d]);
+      mpz_clear (end[d]);
+      mpz_clear (ctr[d]);
+      mpz_clear (stride[d]);
+    }
+  gfc_constructor_free (base);
+  return t;
+}
+
+/* Pull a substring out of an expression.  */
+
+static gfc_try
+find_substring_ref (gfc_expr *p, gfc_expr **newp)
+{
+  int end;
+  int start;
+  int length;
+  gfc_char_t *chr;
+
+  if (p->ref->u.ss.start->expr_type != EXPR_CONSTANT
+      || p->ref->u.ss.end->expr_type != EXPR_CONSTANT)
+    return FAILURE;
+
+  *newp = gfc_copy_expr (p);
+  gfc_free ((*newp)->value.character.string);
+
+  end = (int) mpz_get_ui (p->ref->u.ss.end->value.integer);
+  start = (int) mpz_get_ui (p->ref->u.ss.start->value.integer);
+  length = end - start + 1;
+
+  chr = (*newp)->value.character.string = gfc_get_wide_string (length + 1);
+  (*newp)->value.character.length = length;
+  memcpy (chr, &p->value.character.string[start - 1],
+	  length * sizeof (gfc_char_t));
+  chr[length] = '\0';
+  return SUCCESS;
+}
+
+
+
+/* Simplify a subobject reference of a constructor.  This occurs when
+   parameter variable values are substituted.  */
+
+static gfc_try
+simplify_const_ref (gfc_expr *p)
+{
+  gfc_constructor *cons, *c;
+  gfc_expr *newp;
+  gfc_ref *last_ref;
+
+  while (p->ref)
+    {
+      switch (p->ref->type)
+	{
+	case REF_ARRAY:
+	  switch (p->ref->u.ar.type)
+	    {
+	    case AR_ELEMENT:
+	      /* <type/kind spec>, parameter :: x(<int>) = scalar_expr
+		 will generate this.  */
+	      if (p->expr_type != EXPR_ARRAY)
+		{
+		  remove_subobject_ref (p, NULL);
+		  break;
+		}
+	      if (find_array_element (p->value.constructor, &p->ref->u.ar,
+				      &cons) == FAILURE)
+		return FAILURE;
+
+	      if (!cons)
+		return SUCCESS;
+
+	      remove_subobject_ref (p, cons);
+	      break;
+
+	    case AR_SECTION:
+	      if (find_array_section (p, p->ref) == FAILURE)
+		return FAILURE;
+	      p->ref->u.ar.type = AR_FULL;
+
+	    /* Fall through.  */
+
+	    case AR_FULL:
+	      if (p->ref->next != NULL
+		  && (p->ts.type == BT_CHARACTER || p->ts.type == BT_DERIVED))
+		{
+		  for (c = gfc_constructor_first (p->value.constructor);
+		       c; c = gfc_constructor_next (c))
+		    {
+		      c->expr->ref = gfc_copy_ref (p->ref->next);
+		      if (simplify_const_ref (c->expr) == FAILURE)
+			return FAILURE;
+		    }
+
+		  if (p->ts.type == BT_DERIVED
+			&& p->ref->next
+			&& (c = gfc_constructor_first (p->value.constructor)))
+		    {
+		      /* There may have been component references.  */
+		      p->ts = c->expr->ts;
+		    }
+
+		  last_ref = p->ref;
+		  for (; last_ref->next; last_ref = last_ref->next) {};
+
+		  if (p->ts.type == BT_CHARACTER
+			&& last_ref->type == REF_SUBSTRING)
+		    {
+		      /* If this is a CHARACTER array and we possibly took
+			 a substring out of it, update the type-spec's
+			 character length according to the first element
+			 (as all should have the same length).  */
+		      int string_len;
+		      if ((c = gfc_constructor_first (p->value.constructor)))
+			{
+			  const gfc_expr* first = c->expr;
+			  gcc_assert (first->expr_type == EXPR_CONSTANT);
+			  gcc_assert (first->ts.type == BT_CHARACTER);
+			  string_len = first->value.character.length;
+			}
+		      else
+			string_len = 0;
+
+		      if (!p->ts.u.cl)
+			p->ts.u.cl = gfc_new_charlen (p->symtree->n.sym->ns,
+						      NULL);
+		      else
+			gfc_free_expr (p->ts.u.cl->length);
+
+		      p->ts.u.cl->length
+			= gfc_get_int_expr (gfc_default_integer_kind,
+					    NULL, string_len);
+		    }
+		}
+	      gfc_free_ref_list (p->ref);
+	      p->ref = NULL;
+	      break;
+
+	    default:
+	      return SUCCESS;
+	    }
+
+	  break;
+
+	case REF_COMPONENT:
+	  cons = find_component_ref (p->value.constructor, p->ref);
+	  remove_subobject_ref (p, cons);
+	  break;
+
+	case REF_SUBSTRING:
+  	  if (find_substring_ref (p, &newp) == FAILURE)
+	    return FAILURE;
+
+	  gfc_replace_expr (p, newp);
+	  gfc_free_ref_list (p->ref);
+	  p->ref = NULL;
+	  break;
+	}
+    }
+
+  return SUCCESS;
+}
+
+
+/* Simplify a chain of references.  */
+
+static gfc_try
+simplify_ref_chain (gfc_ref *ref, int type)
+{
+  int n;
+
+  for (; ref; ref = ref->next)
+    {
+      switch (ref->type)
+	{
+	case REF_ARRAY:
+	  for (n = 0; n < ref->u.ar.dimen; n++)
+	    {
+	      if (gfc_simplify_expr (ref->u.ar.start[n], type) == FAILURE)
+		return FAILURE;
+	      if (gfc_simplify_expr (ref->u.ar.end[n], type) == FAILURE)
+		return FAILURE;
+	      if (gfc_simplify_expr (ref->u.ar.stride[n], type) == FAILURE)
+		return FAILURE;
+	    }
+	  break;
+
+	case REF_SUBSTRING:
+	  if (gfc_simplify_expr (ref->u.ss.start, type) == FAILURE)
+	    return FAILURE;
+	  if (gfc_simplify_expr (ref->u.ss.end, type) == FAILURE)
+	    return FAILURE;
+	  break;
+
+	default:
+	  break;
+	}
+    }
+  return SUCCESS;
+}
+
+
+/* Try to substitute the value of a parameter variable.  */
+
+static gfc_try
+simplify_parameter_variable (gfc_expr *p, int type)
+{
+  gfc_expr *e;
+  gfc_try t;
+
+  e = gfc_copy_expr (p->symtree->n.sym->value);
+  if (e == NULL)
+    return FAILURE;
+
+  e->rank = p->rank;
+
+  /* Do not copy subobject refs for constant.  */
+  if (e->expr_type != EXPR_CONSTANT && p->ref != NULL)
+    e->ref = gfc_copy_ref (p->ref);
+  t = gfc_simplify_expr (e, type);
+
+  /* Only use the simplification if it eliminated all subobject references.  */
+  if (t == SUCCESS && !e->ref)
+    gfc_replace_expr (p, e);
+  else
+    gfc_free_expr (e);
+
+  return t;
+}
+
+/* Given an expression, simplify it by collapsing constant
+   expressions.  Most simplification takes place when the expression
+   tree is being constructed.  If an intrinsic function is simplified
+   at some point, we get called again to collapse the result against
+   other constants.
+
+   We work by recursively simplifying expression nodes, simplifying
+   intrinsic functions where possible, which can lead to further
+   constant collapsing.  If an operator has constant operand(s), we
+   rip the expression apart, and rebuild it, hoping that it becomes
+   something simpler.
+
+   The expression type is defined for:
+     0   Basic expression parsing
+     1   Simplifying array constructors -- will substitute
+	 iterator values.
+   Returns FAILURE on error, SUCCESS otherwise.
+   NOTE: Will return SUCCESS even if the expression can not be simplified.  */
+
+gfc_try
+gfc_simplify_expr (gfc_expr *p, int type)
+{
+  gfc_actual_arglist *ap;
+
+  if (p == NULL)
+    return SUCCESS;
+
+  switch (p->expr_type)
+    {
+    case EXPR_CONSTANT:
+    case EXPR_NULL:
+      break;
+
+    case EXPR_FUNCTION:
+      for (ap = p->value.function.actual; ap; ap = ap->next)
+	if (gfc_simplify_expr (ap->expr, type) == FAILURE)
+	  return FAILURE;
+
+      if (p->value.function.isym != NULL
+	  && gfc_intrinsic_func_interface (p, 1) == MATCH_ERROR)
+	return FAILURE;
+
+      break;
+
+    case EXPR_SUBSTRING:
+      if (simplify_ref_chain (p->ref, type) == FAILURE)
+	return FAILURE;
+
+      if (gfc_is_constant_expr (p))
+	{
+	  gfc_char_t *s;
+	  int start, end;
+
+	  start = 0;
+	  if (p->ref && p->ref->u.ss.start)
+	    {
+	      gfc_extract_int (p->ref->u.ss.start, &start);
+	      start--;  /* Convert from one-based to zero-based.  */
+	    }
+
+	  end = p->value.character.length;
+	  if (p->ref && p->ref->u.ss.end)
+	    gfc_extract_int (p->ref->u.ss.end, &end);
+
+	  if (end < 0)
+	    end = 0;
+
+	  s = gfc_get_wide_string (end - start + 2);
+	  memcpy (s, p->value.character.string + start,
+		  (end - start) * sizeof (gfc_char_t));
+	  s[end - start + 1] = '\0';  /* TODO: C-style string.  */
+	  gfc_free (p->value.character.string);
+	  p->value.character.string = s;
+	  p->value.character.length = end - start;
+	  p->ts.u.cl = gfc_new_charlen (gfc_current_ns, NULL);
+	  p->ts.u.cl->length = gfc_get_int_expr (gfc_default_integer_kind,
+						 NULL,
+						 p->value.character.length);
+	  gfc_free_ref_list (p->ref);
+	  p->ref = NULL;
+	  p->expr_type = EXPR_CONSTANT;
+	}
+      break;
+
+    case EXPR_OP:
+      if (simplify_intrinsic_op (p, type) == FAILURE)
+	return FAILURE;
+      break;
+
+    case EXPR_VARIABLE:
+      /* Only substitute array parameter variables if we are in an
+	 initialization expression, or we want a subsection.  */
+      if (p->symtree->n.sym->attr.flavor == FL_PARAMETER
+	  && (gfc_init_expr_flag || p->ref
+	      || p->symtree->n.sym->value->expr_type != EXPR_ARRAY))
+	{
+	  if (simplify_parameter_variable (p, type) == FAILURE)
+	    return FAILURE;
+	  break;
+	}
+
+      if (type == 1)
+	{
+	  gfc_simplify_iterator_var (p);
+	}
+
+      /* Simplify subcomponent references.  */
+      if (simplify_ref_chain (p->ref, type) == FAILURE)
+	return FAILURE;
+
+      break;
+
+    case EXPR_STRUCTURE:
+    case EXPR_ARRAY:
+      if (simplify_ref_chain (p->ref, type) == FAILURE)
+	return FAILURE;
+
+      if (simplify_constructor (p->value.constructor, type) == FAILURE)
+	return FAILURE;
+
+      if (p->expr_type == EXPR_ARRAY && p->ref && p->ref->type == REF_ARRAY
+	  && p->ref->u.ar.type == AR_FULL)
+	  gfc_expand_constructor (p, false);
+
+      if (simplify_const_ref (p) == FAILURE)
+	return FAILURE;
+
+      break;
+
+    case EXPR_COMPCALL:
+    case EXPR_PPC:
+      gcc_unreachable ();
+      break;
+    }
+
+  return SUCCESS;
+}
+
+
+/* Returns the type of an expression with the exception that iterator
+   variables are automatically integers no matter what else they may
+   be declared as.  */
+
+static bt
+et0 (gfc_expr *e)
+{
+  if (e->expr_type == EXPR_VARIABLE && gfc_check_iter_variable (e) == SUCCESS)
+    return BT_INTEGER;
+
+  return e->ts.type;
+}
+
+
+/* Check an intrinsic arithmetic operation to see if it is consistent
+   with some type of expression.  */
+
+static gfc_try check_init_expr (gfc_expr *);
+
+
+/* Scalarize an expression for an elemental intrinsic call.  */
+
+static gfc_try
+scalarize_intrinsic_call (gfc_expr *e)
+{
+  gfc_actual_arglist *a, *b;
+  gfc_constructor_base ctor;
+  gfc_constructor *args[5];
+  gfc_constructor *ci, *new_ctor;
+  gfc_expr *expr, *old;
+  int n, i, rank[5], array_arg;
+  
+  /* Find which, if any, arguments are arrays.  Assume that the old
+     expression carries the type information and that the first arg
+     that is an array expression carries all the shape information.*/
+  n = array_arg = 0;
+  a = e->value.function.actual;
+  for (; a; a = a->next)
+    {
+      n++;
+      if (a->expr->expr_type != EXPR_ARRAY)
+	continue;
+      array_arg = n;
+      expr = gfc_copy_expr (a->expr);
+      break;
+    }
+
+  if (!array_arg)
+    return FAILURE;
+
+  old = gfc_copy_expr (e);
+
+  gfc_constructor_free (expr->value.constructor);
+  expr->value.constructor = NULL;
+  expr->ts = old->ts;
+  expr->where = old->where;
+  expr->expr_type = EXPR_ARRAY;
+
+  /* Copy the array argument constructors into an array, with nulls
+     for the scalars.  */
+  n = 0;
+  a = old->value.function.actual;
+  for (; a; a = a->next)
+    {
+      /* Check that this is OK for an initialization expression.  */
+      if (a->expr && check_init_expr (a->expr) == FAILURE)
+	goto cleanup;
+
+      rank[n] = 0;
+      if (a->expr && a->expr->rank && a->expr->expr_type == EXPR_VARIABLE)
+	{
+	  rank[n] = a->expr->rank;
+	  ctor = a->expr->symtree->n.sym->value->value.constructor;
+	  args[n] = gfc_constructor_first (ctor);
+	}
+      else if (a->expr && a->expr->expr_type == EXPR_ARRAY)
+	{
+	  if (a->expr->rank)
+	    rank[n] = a->expr->rank;
+	  else
+	    rank[n] = 1;
+	  ctor = gfc_constructor_copy (a->expr->value.constructor);
+	  args[n] = gfc_constructor_first (ctor);
+	}
+      else
+	args[n] = NULL;
+
+      n++;
+    }
+
+
+  /* Using the array argument as the master, step through the array
+     calling the function for each element and advancing the array
+     constructors together.  */
+  for (ci = args[array_arg - 1]; ci; ci = gfc_constructor_next (ci))
+    {
+      new_ctor = gfc_constructor_append_expr (&expr->value.constructor,
+					      gfc_copy_expr (old), NULL);
+
+      gfc_free_actual_arglist (new_ctor->expr->value.function.actual);
+      a = NULL;
+      b = old->value.function.actual;
+      for (i = 0; i < n; i++)
+	{
+	  if (a == NULL)
+	    new_ctor->expr->value.function.actual
+			= a = gfc_get_actual_arglist ();
+	  else
+	    {
+	      a->next = gfc_get_actual_arglist ();
+	      a = a->next;
+	    }
+
+	  if (args[i])
+	    a->expr = gfc_copy_expr (args[i]->expr);
+	  else
+	    a->expr = gfc_copy_expr (b->expr);
+
+	  b = b->next;
+	}
+
+      /* Simplify the function calls.  If the simplification fails, the
+	 error will be flagged up down-stream or the library will deal
+	 with it.  */
+      gfc_simplify_expr (new_ctor->expr, 0);
+
+      for (i = 0; i < n; i++)
+	if (args[i])
+	  args[i] = gfc_constructor_next (args[i]);
+
+      for (i = 1; i < n; i++)
+	if (rank[i] && ((args[i] != NULL && args[array_arg - 1] == NULL)
+			|| (args[i] == NULL && args[array_arg - 1] != NULL)))
+	  goto compliance;
+    }
+
+  free_expr0 (e);
+  *e = *expr;
+  gfc_free_expr (old);
+  return SUCCESS;
+
+compliance:
+  gfc_error_now ("elemental function arguments at %C are not compliant");
+
+cleanup:
+  gfc_free_expr (expr);
+  gfc_free_expr (old);
+  return FAILURE;
+}
+
+
+static gfc_try
+check_intrinsic_op (gfc_expr *e, gfc_try (*check_function) (gfc_expr *))
+{
+  gfc_expr *op1 = e->value.op.op1;
+  gfc_expr *op2 = e->value.op.op2;
+
+  if ((*check_function) (op1) == FAILURE)
+    return FAILURE;
+
+  switch (e->value.op.op)
+    {
+    case INTRINSIC_UPLUS:
+    case INTRINSIC_UMINUS:
+      if (!numeric_type (et0 (op1)))
+	goto not_numeric;
+      break;
+
+    case INTRINSIC_EQ:
+    case INTRINSIC_EQ_OS:
+    case INTRINSIC_NE:
+    case INTRINSIC_NE_OS:
+    case INTRINSIC_GT:
+    case INTRINSIC_GT_OS:
+    case INTRINSIC_GE:
+    case INTRINSIC_GE_OS:
+    case INTRINSIC_LT:
+    case INTRINSIC_LT_OS:
+    case INTRINSIC_LE:
+    case INTRINSIC_LE_OS:
+      if ((*check_function) (op2) == FAILURE)
+	return FAILURE;
+      
+      if (!(et0 (op1) == BT_CHARACTER && et0 (op2) == BT_CHARACTER)
+	  && !(numeric_type (et0 (op1)) && numeric_type (et0 (op2))))
+	{
+	  gfc_error ("Numeric or CHARACTER operands are required in "
+		     "expression at %L", &e->where);
+	 return FAILURE;
+	}
+      break;
+
+    case INTRINSIC_PLUS:
+    case INTRINSIC_MINUS:
+    case INTRINSIC_TIMES:
+    case INTRINSIC_DIVIDE:
+    case INTRINSIC_POWER:
+      if ((*check_function) (op2) == FAILURE)
+	return FAILURE;
+
+      if (!numeric_type (et0 (op1)) || !numeric_type (et0 (op2)))
+	goto not_numeric;
+
+      break;
+
+    case INTRINSIC_CONCAT:
+      if ((*check_function) (op2) == FAILURE)
+	return FAILURE;
+
+      if (et0 (op1) != BT_CHARACTER || et0 (op2) != BT_CHARACTER)
+	{
+	  gfc_error ("Concatenation operator in expression at %L "
+		     "must have two CHARACTER operands", &op1->where);
+	  return FAILURE;
+	}
+
+      if (op1->ts.kind != op2->ts.kind)
+	{
+	  gfc_error ("Concat operator at %L must concatenate strings of the "
+		     "same kind", &e->where);
+	  return FAILURE;
+	}
+
+      break;
+
+    case INTRINSIC_NOT:
+      if (et0 (op1) != BT_LOGICAL)
+	{
+	  gfc_error (".NOT. operator in expression at %L must have a LOGICAL "
+		     "operand", &op1->where);
+	  return FAILURE;
+	}
+
+      break;
+
+    case INTRINSIC_AND:
+    case INTRINSIC_OR:
+    case INTRINSIC_EQV:
+    case INTRINSIC_NEQV:
+      if ((*check_function) (op2) == FAILURE)
+	return FAILURE;
+
+      if (et0 (op1) != BT_LOGICAL || et0 (op2) != BT_LOGICAL)
+	{
+	  gfc_error ("LOGICAL operands are required in expression at %L",
+		     &e->where);
+	  return FAILURE;
+	}
+
+      break;
+
+    case INTRINSIC_PARENTHESES:
+      break;
+
+    default:
+      gfc_error ("Only intrinsic operators can be used in expression at %L",
+		 &e->where);
+      return FAILURE;
+    }
+
+  return SUCCESS;
+
+not_numeric:
+  gfc_error ("Numeric operands are required in expression at %L", &e->where);
+
+  return FAILURE;
+}
+
+/* F2003, 7.1.7 (3): In init expression, allocatable components
+   must not be data-initialized.  */
+static gfc_try
+check_alloc_comp_init (gfc_expr *e)
+{
+  gfc_component *comp;
+  gfc_constructor *ctor;
+
+  gcc_assert (e->expr_type == EXPR_STRUCTURE);
+  gcc_assert (e->ts.type == BT_DERIVED);
+
+  for (comp = e->ts.u.derived->components,
+       ctor = gfc_constructor_first (e->value.constructor);
+       comp; comp = comp->next, ctor = gfc_constructor_next (ctor))
+    {
+      if (comp->attr.allocatable
+          && ctor->expr->expr_type != EXPR_NULL)
+        {
+	  gfc_error("Invalid initialization expression for ALLOCATABLE "
+	            "component '%s' in structure constructor at %L",
+	            comp->name, &ctor->expr->where);
+	  return FAILURE;
+	}
+    }
+
+  return SUCCESS;
+}
+
+static match
+check_init_expr_arguments (gfc_expr *e)
+{
+  gfc_actual_arglist *ap;
+
+  for (ap = e->value.function.actual; ap; ap = ap->next)
+    if (check_init_expr (ap->expr) == FAILURE)
+      return MATCH_ERROR;
+
+  return MATCH_YES;
+}
+
+static gfc_try check_restricted (gfc_expr *);
+
+/* F95, 7.1.6.1, Initialization expressions, (7)
+   F2003, 7.1.7 Initialization expression, (8)  */
+
+static match
+check_inquiry (gfc_expr *e, int not_restricted)
+{
+  const char *name;
+  const char *const *functions;
+
+  static const char *const inquiry_func_f95[] = {
+    "lbound", "shape", "size", "ubound",
+    "bit_size", "len", "kind",
+    "digits", "epsilon", "huge", "maxexponent", "minexponent",
+    "precision", "radix", "range", "tiny",
+    NULL
+  };
+
+  static const char *const inquiry_func_f2003[] = {
+    "lbound", "shape", "size", "ubound",
+    "bit_size", "len", "kind",
+    "digits", "epsilon", "huge", "maxexponent", "minexponent",
+    "precision", "radix", "range", "tiny",
+    "new_line", NULL
+  };
+
+  int i;
+  gfc_actual_arglist *ap;
+
+  if (!e->value.function.isym
+      || !e->value.function.isym->inquiry)
+    return MATCH_NO;
+
+  /* An undeclared parameter will get us here (PR25018).  */
+  if (e->symtree == NULL)
+    return MATCH_NO;
+
+  name = e->symtree->n.sym->name;
+
+  functions = (gfc_option.warn_std & GFC_STD_F2003) 
+		? inquiry_func_f2003 : inquiry_func_f95;
+
+  for (i = 0; functions[i]; i++)
+    if (strcmp (functions[i], name) == 0)
+      break;
+
+  if (functions[i] == NULL)
+    return MATCH_ERROR;
+
+  /* At this point we have an inquiry function with a variable argument.  The
+     type of the variable might be undefined, but we need it now, because the
+     arguments of these functions are not allowed to be undefined.  */
+
+  for (ap = e->value.function.actual; ap; ap = ap->next)
+    {
+      if (!ap->expr)
+	continue;
+
+      if (ap->expr->ts.type == BT_UNKNOWN)
+	{
+	  if (ap->expr->symtree->n.sym->ts.type == BT_UNKNOWN
+	      && gfc_set_default_type (ap->expr->symtree->n.sym, 0, gfc_current_ns)
+	      == FAILURE)
+	    return MATCH_NO;
+
+	  ap->expr->ts = ap->expr->symtree->n.sym->ts;
+	}
+
+	/* Assumed character length will not reduce to a constant expression
+	   with LEN, as required by the standard.  */
+	if (i == 5 && not_restricted
+	    && ap->expr->symtree->n.sym->ts.type == BT_CHARACTER
+	    && (ap->expr->symtree->n.sym->ts.u.cl->length == NULL
+		|| ap->expr->symtree->n.sym->ts.deferred))
+	  {
+	    gfc_error ("Assumed or deferred character length variable '%s' "
+			" in constant expression at %L",
+			ap->expr->symtree->n.sym->name,
+			&ap->expr->where);
+	      return MATCH_ERROR;
+	  }
+	else if (not_restricted && check_init_expr (ap->expr) == FAILURE)
+	  return MATCH_ERROR;
+
+	if (not_restricted == 0
+	      && ap->expr->expr_type != EXPR_VARIABLE
+	      && check_restricted (ap->expr) == FAILURE)
+	  return MATCH_ERROR;
+
+	if (not_restricted == 0
+	    && ap->expr->expr_type == EXPR_VARIABLE
+	    && ap->expr->symtree->n.sym->attr.dummy
+	    && ap->expr->symtree->n.sym->attr.optional)
+	  return MATCH_NO;
+    }
+
+  return MATCH_YES;
+}
+
+
+/* F95, 7.1.6.1, Initialization expressions, (5)
+   F2003, 7.1.7 Initialization expression, (5)  */
+
+static match
+check_transformational (gfc_expr *e)
+{
+  static const char * const trans_func_f95[] = {
+    "repeat", "reshape", "selected_int_kind",
+    "selected_real_kind", "transfer", "trim", NULL
+  };
+
+  static const char * const trans_func_f2003[] =  {
+    "all", "any", "count", "dot_product", "matmul", "null", "pack",
+    "product", "repeat", "reshape", "selected_char_kind", "selected_int_kind",
+    "selected_real_kind", "spread", "sum", "transfer", "transpose",
+    "trim", "unpack", NULL
+  };
+
+  int i;
+  const char *name;
+  const char *const *functions;
+
+  if (!e->value.function.isym
+      || !e->value.function.isym->transformational)
+    return MATCH_NO;
+
+  name = e->symtree->n.sym->name;
+
+  functions = (gfc_option.allow_std & GFC_STD_F2003) 
+		? trans_func_f2003 : trans_func_f95;
+
+  /* NULL() is dealt with below.  */
+  if (strcmp ("null", name) == 0)
+    return MATCH_NO;
+
+  for (i = 0; functions[i]; i++)
+    if (strcmp (functions[i], name) == 0)
+       break;
+
+  if (functions[i] == NULL)
+    {
+      gfc_error("transformational intrinsic '%s' at %L is not permitted "
+		"in an initialization expression", name, &e->where);
+      return MATCH_ERROR;
+    }
+
+  return check_init_expr_arguments (e);
+}
+
+
+/* F95, 7.1.6.1, Initialization expressions, (6)
+   F2003, 7.1.7 Initialization expression, (6)  */
+
+static match
+check_null (gfc_expr *e)
+{
+  if (strcmp ("null", e->symtree->n.sym->name) != 0)
+    return MATCH_NO;
+
+  return check_init_expr_arguments (e);
+}
+
+
+static match
+check_elemental (gfc_expr *e)
+{
+  if (!e->value.function.isym
+      || !e->value.function.isym->elemental)
+    return MATCH_NO;
+
+  if (e->ts.type != BT_INTEGER
+      && e->ts.type != BT_CHARACTER
+      && gfc_notify_std (GFC_STD_F2003, "Extension: Evaluation of "
+			"nonstandard initialization expression at %L",
+			&e->where) == FAILURE)
+    return MATCH_ERROR;
+
+  return check_init_expr_arguments (e);
+}
+
+
+static match
+check_conversion (gfc_expr *e)
+{
+  if (!e->value.function.isym
+      || !e->value.function.isym->conversion)
+    return MATCH_NO;
+
+  return check_init_expr_arguments (e);
+}
+
+
+/* Verify that an expression is an initialization expression.  A side
+   effect is that the expression tree is reduced to a single constant
+   node if all goes well.  This would normally happen when the
+   expression is constructed but function references are assumed to be
+   intrinsics in the context of initialization expressions.  If
+   FAILURE is returned an error message has been generated.  */
+
+static gfc_try
+check_init_expr (gfc_expr *e)
+{
+  match m;
+  gfc_try t;
+
+  if (e == NULL)
+    return SUCCESS;
+
+  switch (e->expr_type)
+    {
+    case EXPR_OP:
+      t = check_intrinsic_op (e, check_init_expr);
+      if (t == SUCCESS)
+	t = gfc_simplify_expr (e, 0);
+
+      break;
+
+    case EXPR_FUNCTION:
+      t = FAILURE;
+
+      {
+	gfc_intrinsic_sym* isym;
+	gfc_symbol* sym;
+
+	sym = e->symtree->n.sym;
+	if (!gfc_is_intrinsic (sym, 0, e->where)
+	    || (m = gfc_intrinsic_func_interface (e, 0)) != MATCH_YES)
+	  {
+	    gfc_error ("Function '%s' in initialization expression at %L "
+		       "must be an intrinsic function",
+		       e->symtree->n.sym->name, &e->where);
+	    break;
+	  }
+
+	if ((m = check_conversion (e)) == MATCH_NO
+	    && (m = check_inquiry (e, 1)) == MATCH_NO
+	    && (m = check_null (e)) == MATCH_NO
+	    && (m = check_transformational (e)) == MATCH_NO
+	    && (m = check_elemental (e)) == MATCH_NO)
+	  {
+	    gfc_error ("Intrinsic function '%s' at %L is not permitted "
+		       "in an initialization expression",
+		       e->symtree->n.sym->name, &e->where);
+	    m = MATCH_ERROR;
+	  }
+
+	if (m == MATCH_ERROR)
+	  return FAILURE;
+
+	/* Try to scalarize an elemental intrinsic function that has an
+	   array argument.  */
+	isym = gfc_find_function (e->symtree->n.sym->name);
+	if (isym && isym->elemental
+	    && (t = scalarize_intrinsic_call (e)) == SUCCESS)
+	  break;
+      }
+
+      if (m == MATCH_YES)
+	t = gfc_simplify_expr (e, 0);
+
+      break;
+
+    case EXPR_VARIABLE:
+      t = SUCCESS;
+
+      if (gfc_check_iter_variable (e) == SUCCESS)
+	break;
+
+      if (e->symtree->n.sym->attr.flavor == FL_PARAMETER)
+	{
+	  /* A PARAMETER shall not be used to define itself, i.e.
+		REAL, PARAMETER :: x = transfer(0, x)
+	     is invalid.  */
+	  if (!e->symtree->n.sym->value)
+	    {
+	      gfc_error("PARAMETER '%s' is used at %L before its definition "
+			"is complete", e->symtree->n.sym->name, &e->where);
+	      t = FAILURE;
+	    }
+	  else
+	    t = simplify_parameter_variable (e, 0);
+
+	  break;
+	}
+
+      if (gfc_in_match_data ())
+	break;
+
+      t = FAILURE;
+
+      if (e->symtree->n.sym->as)
+	{
+	  switch (e->symtree->n.sym->as->type)
+	    {
+	      case AS_ASSUMED_SIZE:
+		gfc_error ("Assumed size array '%s' at %L is not permitted "
+			   "in an initialization expression",
+			   e->symtree->n.sym->name, &e->where);
+		break;
+
+	      case AS_ASSUMED_SHAPE:
+		gfc_error ("Assumed shape array '%s' at %L is not permitted "
+			   "in an initialization expression",
+			   e->symtree->n.sym->name, &e->where);
+		break;
+
+	      case AS_DEFERRED:
+		gfc_error ("Deferred array '%s' at %L is not permitted "
+			   "in an initialization expression",
+			   e->symtree->n.sym->name, &e->where);
+		break;
+
+	      case AS_EXPLICIT:
+		gfc_error ("Array '%s' at %L is a variable, which does "
+			   "not reduce to a constant expression",
+			   e->symtree->n.sym->name, &e->where);
+		break;
+
+	      default:
+		gcc_unreachable();
+	  }
+	}
+      else
+	gfc_error ("Parameter '%s' at %L has not been declared or is "
+		   "a variable, which does not reduce to a constant "
+		   "expression", e->symtree->n.sym->name, &e->where);
+
+      break;
+
+    case EXPR_CONSTANT:
+    case EXPR_NULL:
+      t = SUCCESS;
+      break;
+
+    case EXPR_SUBSTRING:
+      t = check_init_expr (e->ref->u.ss.start);
+      if (t == FAILURE)
+	break;
+
+      t = check_init_expr (e->ref->u.ss.end);
+      if (t == SUCCESS)
+	t = gfc_simplify_expr (e, 0);
+
+      break;
+
+    case EXPR_STRUCTURE:
+      t = e->ts.is_iso_c ? SUCCESS : FAILURE;
+      if (t == SUCCESS)
+	break;
+
+      t = check_alloc_comp_init (e);
+      if (t == FAILURE)
+	break;
+
+      t = gfc_check_constructor (e, check_init_expr);
+      if (t == FAILURE)
+	break;
+
+      break;
+
+    case EXPR_ARRAY:
+      t = gfc_check_constructor (e, check_init_expr);
+      if (t == FAILURE)
+	break;
+
+      t = gfc_expand_constructor (e, true);
+      if (t == FAILURE)
+	break;
+
+      t = gfc_check_constructor_type (e);
+      break;
+
+    default:
+      gfc_internal_error ("check_init_expr(): Unknown expression type");
+    }
+
+  return t;
+}
+
+/* Reduces a general expression to an initialization expression (a constant).
+   This used to be part of gfc_match_init_expr.
+   Note that this function doesn't free the given expression on FAILURE.  */
+
+gfc_try
+gfc_reduce_init_expr (gfc_expr *expr)
+{
+  gfc_try t;
+
+  gfc_init_expr_flag = true;
+  t = gfc_resolve_expr (expr);
+  if (t == SUCCESS)
+    t = check_init_expr (expr);
+  gfc_init_expr_flag = false;
+
+  if (t == FAILURE)
+    return FAILURE;
+
+  if (expr->expr_type == EXPR_ARRAY)
+    {
+      if (gfc_check_constructor_type (expr) == FAILURE)
+	return FAILURE;
+      if (gfc_expand_constructor (expr, true) == FAILURE)
+	return FAILURE;
+    }
+
+  return SUCCESS;
+}
+
+
+/* Match an initialization expression.  We work by first matching an
+   expression, then reducing it to a constant.  */
+
+match
+gfc_match_init_expr (gfc_expr **result)
+{
+  gfc_expr *expr;
+  match m;
+  gfc_try t;
+
+  expr = NULL;
+
+  gfc_init_expr_flag = true;
+
+  m = gfc_match_expr (&expr);
+  if (m != MATCH_YES)
+    {
+      gfc_init_expr_flag = false;
+      return m;
+    }
+
+  t = gfc_reduce_init_expr (expr);
+  if (t != SUCCESS)
+    {
+      gfc_free_expr (expr);
+      gfc_init_expr_flag = false;
+      return MATCH_ERROR;
+    }
+
+  *result = expr;
+  gfc_init_expr_flag = false;
+
+  return MATCH_YES;
+}
+
+
+/* Given an actual argument list, test to see that each argument is a
+   restricted expression and optionally if the expression type is
+   integer or character.  */
+
+static gfc_try
+restricted_args (gfc_actual_arglist *a)
+{
+  for (; a; a = a->next)
+    {
+      if (check_restricted (a->expr) == FAILURE)
+	return FAILURE;
+    }
+
+  return SUCCESS;
+}
+
+
+/************* Restricted/specification expressions *************/
+
+
+/* Make sure a non-intrinsic function is a specification function.  */
+
+static gfc_try
+external_spec_function (gfc_expr *e)
+{
+  gfc_symbol *f;
+
+  f = e->value.function.esym;
+
+  if (f->attr.proc == PROC_ST_FUNCTION)
+    {
+      gfc_error ("Specification function '%s' at %L cannot be a statement "
+		 "function", f->name, &e->where);
+      return FAILURE;
+    }
+
+  if (f->attr.proc == PROC_INTERNAL)
+    {
+      gfc_error ("Specification function '%s' at %L cannot be an internal "
+		 "function", f->name, &e->where);
+      return FAILURE;
+    }
+
+  if (!f->attr.pure && !f->attr.elemental)
+    {
+      gfc_error ("Specification function '%s' at %L must be PURE", f->name,
+		 &e->where);
+      return FAILURE;
+    }
+
+  if (f->attr.recursive)
+    {
+      gfc_error ("Specification function '%s' at %L cannot be RECURSIVE",
+		 f->name, &e->where);
+      return FAILURE;
+    }
+
+  return restricted_args (e->value.function.actual);
+}
+
+
+/* Check to see that a function reference to an intrinsic is a
+   restricted expression.  */
+
+static gfc_try
+restricted_intrinsic (gfc_expr *e)
+{
+  /* TODO: Check constraints on inquiry functions.  7.1.6.2 (7).  */
+  if (check_inquiry (e, 0) == MATCH_YES)
+    return SUCCESS;
+
+  return restricted_args (e->value.function.actual);
+}
+
+
+/* Check the expressions of an actual arglist.  Used by check_restricted.  */
+
+static gfc_try
+check_arglist (gfc_actual_arglist* arg, gfc_try (*checker) (gfc_expr*))
+{
+  for (; arg; arg = arg->next)
+    if (checker (arg->expr) == FAILURE)
+      return FAILURE;
+
+  return SUCCESS;
+}
+
+
+/* Check the subscription expressions of a reference chain with a checking
+   function; used by check_restricted.  */
+
+static gfc_try
+check_references (gfc_ref* ref, gfc_try (*checker) (gfc_expr*))
+{
+  int dim;
+
+  if (!ref)
+    return SUCCESS;
+
+  switch (ref->type)
+    {
+    case REF_ARRAY:
+      for (dim = 0; dim != ref->u.ar.dimen; ++dim)
+	{
+	  if (checker (ref->u.ar.start[dim]) == FAILURE)
+	    return FAILURE;
+	  if (checker (ref->u.ar.end[dim]) == FAILURE)
+	    return FAILURE;
+	  if (checker (ref->u.ar.stride[dim]) == FAILURE)
+	    return FAILURE;
+	}
+      break;
+
+    case REF_COMPONENT:
+      /* Nothing needed, just proceed to next reference.  */
+      break;
+
+    case REF_SUBSTRING:
+      if (checker (ref->u.ss.start) == FAILURE)
+	return FAILURE;
+      if (checker (ref->u.ss.end) == FAILURE)
+	return FAILURE;
+      break;
+
+    default:
+      gcc_unreachable ();
+      break;
+    }
+
+  return check_references (ref->next, checker);
+}
+
+
+/* Verify that an expression is a restricted expression.  Like its
+   cousin check_init_expr(), an error message is generated if we
+   return FAILURE.  */
+
+static gfc_try
+check_restricted (gfc_expr *e)
+{
+  gfc_symbol* sym;
+  gfc_try t;
+
+  if (e == NULL)
+    return SUCCESS;
+
+  switch (e->expr_type)
+    {
+    case EXPR_OP:
+      t = check_intrinsic_op (e, check_restricted);
+      if (t == SUCCESS)
+	t = gfc_simplify_expr (e, 0);
+
+      break;
+
+    case EXPR_FUNCTION:
+      if (e->value.function.esym)
+	{
+	  t = check_arglist (e->value.function.actual, &check_restricted);
+	  if (t == SUCCESS)
+	    t = external_spec_function (e);
+	}
+      else
+	{
+	  if (e->value.function.isym && e->value.function.isym->inquiry)
+	    t = SUCCESS;
+	  else
+	    t = check_arglist (e->value.function.actual, &check_restricted);
+
+	  if (t == SUCCESS)
+	    t = restricted_intrinsic (e);
+	}
+      break;
+
+    case EXPR_VARIABLE:
+      sym = e->symtree->n.sym;
+      t = FAILURE;
+
+      /* If a dummy argument appears in a context that is valid for a
+	 restricted expression in an elemental procedure, it will have
+	 already been simplified away once we get here.  Therefore we
+	 don't need to jump through hoops to distinguish valid from
+	 invalid cases.  */
+      if (sym->attr.dummy && sym->ns == gfc_current_ns
+	  && sym->ns->proc_name && sym->ns->proc_name->attr.elemental)
+	{
+	  gfc_error ("Dummy argument '%s' not allowed in expression at %L",
+		     sym->name, &e->where);
+	  break;
+	}
+
+      if (sym->attr.optional)
+	{
+	  gfc_error ("Dummy argument '%s' at %L cannot be OPTIONAL",
+		     sym->name, &e->where);
+	  break;
+	}
+
+      if (sym->attr.intent == INTENT_OUT)
+	{
+	  gfc_error ("Dummy argument '%s' at %L cannot be INTENT(OUT)",
+		     sym->name, &e->where);
+	  break;
+	}
+
+      /* Check reference chain if any.  */
+      if (check_references (e->ref, &check_restricted) == FAILURE)
+	break;
+
+      /* gfc_is_formal_arg broadcasts that a formal argument list is being
+	 processed in resolve.c(resolve_formal_arglist).  This is done so
+	 that host associated dummy array indices are accepted (PR23446).
+	 This mechanism also does the same for the specification expressions
+	 of array-valued functions.  */
+      if (e->error
+	    || sym->attr.in_common
+	    || sym->attr.use_assoc
+	    || sym->attr.dummy
+	    || sym->attr.implied_index
+	    || sym->attr.flavor == FL_PARAMETER
+	    || (sym->ns && sym->ns == gfc_current_ns->parent)
+	    || (sym->ns && gfc_current_ns->parent
+		  && sym->ns == gfc_current_ns->parent->parent)
+	    || (sym->ns->proc_name != NULL
+		  && sym->ns->proc_name->attr.flavor == FL_MODULE)
+	    || (gfc_is_formal_arg () && (sym->ns == gfc_current_ns)))
+	{
+	  t = SUCCESS;
+	  break;
+	}
+
+      gfc_error ("Variable '%s' cannot appear in the expression at %L",
+		 sym->name, &e->where);
+      /* Prevent a repetition of the error.  */
+      e->error = 1;
+      break;
+
+    case EXPR_NULL:
+    case EXPR_CONSTANT:
+      t = SUCCESS;
+      break;
+
+    case EXPR_SUBSTRING:
+      t = gfc_specification_expr (e->ref->u.ss.start);
+      if (t == FAILURE)
+	break;
+
+      t = gfc_specification_expr (e->ref->u.ss.end);
+      if (t == SUCCESS)
+	t = gfc_simplify_expr (e, 0);
+
+      break;
+
+    case EXPR_STRUCTURE:
+      t = gfc_check_constructor (e, check_restricted);
+      break;
+
+    case EXPR_ARRAY:
+      t = gfc_check_constructor (e, check_restricted);
+      break;
+
+    default:
+      gfc_internal_error ("check_restricted(): Unknown expression type");
+    }
+
+  return t;
+}
+
+
+/* Check to see that an expression is a specification expression.  If
+   we return FAILURE, an error has been generated.  */
+
+gfc_try
+gfc_specification_expr (gfc_expr *e)
+{
+  gfc_component *comp;
+
+  if (e == NULL)
+    return SUCCESS;
+
+  if (e->ts.type != BT_INTEGER)
+    {
+      gfc_error ("Expression at %L must be of INTEGER type, found %s",
+		 &e->where, gfc_basic_typename (e->ts.type));
+      return FAILURE;
+    }
+
+  if (e->expr_type == EXPR_FUNCTION
+	  && !e->value.function.isym
+	  && !e->value.function.esym
+	  && !gfc_pure (e->symtree->n.sym)
+	  && (!gfc_is_proc_ptr_comp (e, &comp)
+	      || !comp->attr.pure))
+    {
+      gfc_error ("Function '%s' at %L must be PURE",
+		 e->symtree->n.sym->name, &e->where);
+      /* Prevent repeat error messages.  */
+      e->symtree->n.sym->attr.pure = 1;
+      return FAILURE;
+    }
+
+  if (e->rank != 0)
+    {
+      gfc_error ("Expression at %L must be scalar", &e->where);
+      return FAILURE;
+    }
+
+  if (gfc_simplify_expr (e, 0) == FAILURE)
+    return FAILURE;
+
+  return check_restricted (e);
+}
+
+
+/************** Expression conformance checks.  *************/
+
+/* Given two expressions, make sure that the arrays are conformable.  */
+
+gfc_try
+gfc_check_conformance (gfc_expr *op1, gfc_expr *op2, const char *optype_msgid, ...)
+{
+  int op1_flag, op2_flag, d;
+  mpz_t op1_size, op2_size;
+  gfc_try t;
+
+  va_list argp;
+  char buffer[240];
+
+  if (op1->rank == 0 || op2->rank == 0)
+    return SUCCESS;
+
+  va_start (argp, optype_msgid);
+  vsnprintf (buffer, 240, optype_msgid, argp);
+  va_end (argp);
+
+  if (op1->rank != op2->rank)
+    {
+      gfc_error ("Incompatible ranks in %s (%d and %d) at %L", _(buffer),
+		 op1->rank, op2->rank, &op1->where);
+      return FAILURE;
+    }
+
+  t = SUCCESS;
+
+  for (d = 0; d < op1->rank; d++)
+    {
+      op1_flag = gfc_array_dimen_size (op1, d, &op1_size) == SUCCESS;
+      op2_flag = gfc_array_dimen_size (op2, d, &op2_size) == SUCCESS;
+
+      if (op1_flag && op2_flag && mpz_cmp (op1_size, op2_size) != 0)
+	{
+	  gfc_error ("Different shape for %s at %L on dimension %d "
+		     "(%d and %d)", _(buffer), &op1->where, d + 1,
+		     (int) mpz_get_si (op1_size),
+		     (int) mpz_get_si (op2_size));
+
+	  t = FAILURE;
+	}
+
+      if (op1_flag)
+	mpz_clear (op1_size);
+      if (op2_flag)
+	mpz_clear (op2_size);
+
+      if (t == FAILURE)
+	return FAILURE;
+    }
+
+  return SUCCESS;
+}
+
+
+/* Given an assignable expression and an arbitrary expression, make
+   sure that the assignment can take place.  */
+
+gfc_try
+gfc_check_assign (gfc_expr *lvalue, gfc_expr *rvalue, int conform)
+{
+  gfc_symbol *sym;
+  gfc_ref *ref;
+  int has_pointer;
+
+  sym = lvalue->symtree->n.sym;
+
+  /* See if this is the component or subcomponent of a pointer.  */
+  has_pointer = sym->attr.pointer;
+  for (ref = lvalue->ref; ref; ref = ref->next)
+    if (ref->type == REF_COMPONENT && ref->u.c.component->attr.pointer)
+      {
+	has_pointer = 1;
+	break;
+      }
+
+  /* 12.5.2.2, Note 12.26: The result variable is very similar to any other
+     variable local to a function subprogram.  Its existence begins when
+     execution of the function is initiated and ends when execution of the
+     function is terminated...
+     Therefore, the left hand side is no longer a variable, when it is:  */
+  if (sym->attr.flavor == FL_PROCEDURE && sym->attr.proc != PROC_ST_FUNCTION
+      && !sym->attr.external)
+    {
+      bool bad_proc;
+      bad_proc = false;
+
+      /* (i) Use associated;  */
+      if (sym->attr.use_assoc)
+	bad_proc = true;
+
+      /* (ii) The assignment is in the main program; or  */
+      if (gfc_current_ns->proc_name->attr.is_main_program)
+	bad_proc = true;
+
+      /* (iii) A module or internal procedure...  */
+      if ((gfc_current_ns->proc_name->attr.proc == PROC_INTERNAL
+	   || gfc_current_ns->proc_name->attr.proc == PROC_MODULE)
+	  && gfc_current_ns->parent
+	  && (!(gfc_current_ns->parent->proc_name->attr.function
+		|| gfc_current_ns->parent->proc_name->attr.subroutine)
+	      || gfc_current_ns->parent->proc_name->attr.is_main_program))
+	{
+	  /* ... that is not a function...  */ 
+	  if (!gfc_current_ns->proc_name->attr.function)
+	    bad_proc = true;
+
+	  /* ... or is not an entry and has a different name.  */
+	  if (!sym->attr.entry && sym->name != gfc_current_ns->proc_name->name)
+	    bad_proc = true;
+	}
+
+      /* (iv) Host associated and not the function symbol or the
+	      parent result.  This picks up sibling references, which
+	      cannot be entries.  */
+      if (!sym->attr.entry
+	    && sym->ns == gfc_current_ns->parent
+	    && sym != gfc_current_ns->proc_name
+	    && sym != gfc_current_ns->parent->proc_name->result)
+	bad_proc = true;
+
+      if (bad_proc)
+	{
+	  gfc_error ("'%s' at %L is not a VALUE", sym->name, &lvalue->where);
+	  return FAILURE;
+	}
+    }
+
+  if (rvalue->rank != 0 && lvalue->rank != rvalue->rank)
+    {
+      gfc_error ("Incompatible ranks %d and %d in assignment at %L",
+		 lvalue->rank, rvalue->rank, &lvalue->where);
+      return FAILURE;
+    }
+
+  if (lvalue->ts.type == BT_UNKNOWN)
+    {
+      gfc_error ("Variable type is UNKNOWN in assignment at %L",
+		 &lvalue->where);
+      return FAILURE;
+    }
+
+  if (rvalue->expr_type == EXPR_NULL)
+    {  
+      if (has_pointer && (ref == NULL || ref->next == NULL)
+	  && lvalue->symtree->n.sym->attr.data)
+        return SUCCESS;
+      else
+	{
+	  gfc_error ("NULL appears on right-hand side in assignment at %L",
+		     &rvalue->where);
+	  return FAILURE;
+	}
+    }
+
+  /* This is possibly a typo: x = f() instead of x => f().  */
+  if (gfc_option.warn_surprising 
+      && rvalue->expr_type == EXPR_FUNCTION
+      && rvalue->symtree->n.sym->attr.pointer)
+    gfc_warning ("POINTER valued function appears on right-hand side of "
+		 "assignment at %L", &rvalue->where);
+
+  /* Check size of array assignments.  */
+  if (lvalue->rank != 0 && rvalue->rank != 0
+      && gfc_check_conformance (lvalue, rvalue, "array assignment") != SUCCESS)
+    return FAILURE;
+
+  if (rvalue->is_boz && lvalue->ts.type != BT_INTEGER
+      && lvalue->symtree->n.sym->attr.data
+      && gfc_notify_std (GFC_STD_GNU, "Extension: BOZ literal at %L used to "
+                         "initialize non-integer variable '%s'",
+			 &rvalue->where, lvalue->symtree->n.sym->name)
+	 == FAILURE)
+    return FAILURE;
+  else if (rvalue->is_boz && !lvalue->symtree->n.sym->attr.data
+      && gfc_notify_std (GFC_STD_GNU, "Extension: BOZ literal at %L outside "
+			 "a DATA statement and outside INT/REAL/DBLE/CMPLX",
+			 &rvalue->where) == FAILURE)
+    return FAILURE;
+
+  /* Handle the case of a BOZ literal on the RHS.  */
+  if (rvalue->is_boz && lvalue->ts.type != BT_INTEGER)
+    {
+      int rc;
+      if (gfc_option.warn_surprising)
+        gfc_warning ("BOZ literal at %L is bitwise transferred "
+                     "non-integer symbol '%s'", &rvalue->where,
+                     lvalue->symtree->n.sym->name);
+      if (!gfc_convert_boz (rvalue, &lvalue->ts))
+	return FAILURE;
+      if ((rc = gfc_range_check (rvalue)) != ARITH_OK)
+	{
+	  if (rc == ARITH_UNDERFLOW)
+	    gfc_error ("Arithmetic underflow of bit-wise transferred BOZ at %L"
+		       ". This check can be disabled with the option "
+		       "-fno-range-check", &rvalue->where);
+	  else if (rc == ARITH_OVERFLOW)
+	    gfc_error ("Arithmetic overflow of bit-wise transferred BOZ at %L"
+		       ". This check can be disabled with the option "
+		       "-fno-range-check", &rvalue->where);
+	  else if (rc == ARITH_NAN)
+	    gfc_error ("Arithmetic NaN of bit-wise transferred BOZ at %L"
+		       ". This check can be disabled with the option "
+		       "-fno-range-check", &rvalue->where);
+	  return FAILURE;
+	}
+    }
+
+  if (gfc_compare_types (&lvalue->ts, &rvalue->ts))
+    return SUCCESS;
+
+  /* Only DATA Statements come here.  */
+  if (!conform)
+    {
+      /* Numeric can be converted to any other numeric. And Hollerith can be
+	 converted to any other type.  */
+      if ((gfc_numeric_ts (&lvalue->ts) && gfc_numeric_ts (&rvalue->ts))
+	  || rvalue->ts.type == BT_HOLLERITH)
+	return SUCCESS;
+
+      if (lvalue->ts.type == BT_LOGICAL && rvalue->ts.type == BT_LOGICAL)
+	return SUCCESS;
+
+      gfc_error ("Incompatible types in DATA statement at %L; attempted "
+		 "conversion of %s to %s", &lvalue->where,
+		 gfc_typename (&rvalue->ts), gfc_typename (&lvalue->ts));
+
+      return FAILURE;
+    }
+
+  /* Assignment is the only case where character variables of different
+     kind values can be converted into one another.  */
+  if (lvalue->ts.type == BT_CHARACTER && rvalue->ts.type == BT_CHARACTER)
+    {
+      if (lvalue->ts.kind != rvalue->ts.kind)
+	gfc_convert_chartype (rvalue, &lvalue->ts);
+
+      return SUCCESS;
+    }
+
+  return gfc_convert_type (rvalue, &lvalue->ts, 1);
+}
+
+
+/* Check that a pointer assignment is OK.  We first check lvalue, and
+   we only check rvalue if it's not an assignment to NULL() or a
+   NULLIFY statement.  */
+
+gfc_try
+gfc_check_pointer_assign (gfc_expr *lvalue, gfc_expr *rvalue)
+{
+  symbol_attribute attr;
+  gfc_ref *ref;
+  bool is_pure, is_implicit_pure, rank_remap;
+  int proc_pointer;
+
+  if (lvalue->symtree->n.sym->ts.type == BT_UNKNOWN
+      && !lvalue->symtree->n.sym->attr.proc_pointer)
+    {
+      gfc_error ("Pointer assignment target is not a POINTER at %L",
+		 &lvalue->where);
+      return FAILURE;
+    }
+
+  if (lvalue->symtree->n.sym->attr.flavor == FL_PROCEDURE
+      && lvalue->symtree->n.sym->attr.use_assoc
+      && !lvalue->symtree->n.sym->attr.proc_pointer)
+    {
+      gfc_error ("'%s' in the pointer assignment at %L cannot be an "
+		 "l-value since it is a procedure",
+		 lvalue->symtree->n.sym->name, &lvalue->where);
+      return FAILURE;
+    }
+
+  proc_pointer = lvalue->symtree->n.sym->attr.proc_pointer;
+
+  rank_remap = false;
+  for (ref = lvalue->ref; ref; ref = ref->next)
+    {
+      if (ref->type == REF_COMPONENT)
+	proc_pointer = ref->u.c.component->attr.proc_pointer;
+
+      if (ref->type == REF_ARRAY && ref->next == NULL)
+	{
+	  int dim;
+
+	  if (ref->u.ar.type == AR_FULL)
+	    break;
+
+	  if (ref->u.ar.type != AR_SECTION)
+	    {
+	      gfc_error ("Expected bounds specification for '%s' at %L",
+			 lvalue->symtree->n.sym->name, &lvalue->where);
+	      return FAILURE;
+	    }
+
+	  if (gfc_notify_std (GFC_STD_F2003,"Fortran 2003: Bounds "
+			      "specification for '%s' in pointer assignment "
+			      "at %L", lvalue->symtree->n.sym->name,
+			      &lvalue->where) == FAILURE)
+	    return FAILURE;
+
+	  /* When bounds are given, all lbounds are necessary and either all
+	     or none of the upper bounds; no strides are allowed.  If the
+	     upper bounds are present, we may do rank remapping.  */
+	  for (dim = 0; dim < ref->u.ar.dimen; ++dim)
+	    {
+	      if (!ref->u.ar.start[dim])
+		{
+		  gfc_error ("Lower bound has to be present at %L",
+			     &lvalue->where);
+		  return FAILURE;
+		}
+	      if (ref->u.ar.stride[dim])
+		{
+		  gfc_error ("Stride must not be present at %L",
+			     &lvalue->where);
+		  return FAILURE;
+		}
+
+	      if (dim == 0)
+		rank_remap = (ref->u.ar.end[dim] != NULL);
+	      else
+		{
+		  if ((rank_remap && !ref->u.ar.end[dim])
+		      || (!rank_remap && ref->u.ar.end[dim]))
+		    {
+		      gfc_error ("Either all or none of the upper bounds"
+				 " must be specified at %L", &lvalue->where);
+		      return FAILURE;
+		    }
+		}
+	    }
+	}
+    }
+
+  is_pure = gfc_pure (NULL);
+  is_implicit_pure = gfc_implicit_pure (NULL);
+
+  /* If rvalue is a NULL() or NULLIFY, we're done. Otherwise the type,
+     kind, etc for lvalue and rvalue must match, and rvalue must be a
+     pure variable if we're in a pure function.  */
+  if (rvalue->expr_type == EXPR_NULL && rvalue->ts.type == BT_UNKNOWN)
+    return SUCCESS;
+
+  /* F2008, C723 (pointer) and C726 (proc-pointer); for PURE also C1283.  */
+  if (lvalue->expr_type == EXPR_VARIABLE
+      && gfc_is_coindexed (lvalue))
+    {
+      gfc_ref *ref;
+      for (ref = lvalue->ref; ref; ref = ref->next)
+	if (ref->type == REF_ARRAY && ref->u.ar.codimen)
+	  {
+	    gfc_error ("Pointer object at %L shall not have a coindex",
+		       &lvalue->where);
+	    return FAILURE;
+	  }
+    }
+
+  /* Checks on rvalue for procedure pointer assignments.  */
+  if (proc_pointer)
+    {
+      char err[200];
+      gfc_symbol *s1,*s2;
+      gfc_component *comp;
+      const char *name;
+
+      attr = gfc_expr_attr (rvalue);
+      if (!((rvalue->expr_type == EXPR_NULL)
+	    || (rvalue->expr_type == EXPR_FUNCTION && attr.proc_pointer)
+	    || (rvalue->expr_type == EXPR_VARIABLE && attr.proc_pointer)
+	    || (rvalue->expr_type == EXPR_VARIABLE
+		&& attr.flavor == FL_PROCEDURE)))
+	{
+	  gfc_error ("Invalid procedure pointer assignment at %L",
+		     &rvalue->where);
+	  return FAILURE;
+	}
+      if (attr.abstract)
+	{
+	  gfc_error ("Abstract interface '%s' is invalid "
+		     "in procedure pointer assignment at %L",
+		     rvalue->symtree->name, &rvalue->where);
+	  return FAILURE;
+	}
+      /* Check for C727.  */
+      if (attr.flavor == FL_PROCEDURE)
+	{
+	  if (attr.proc == PROC_ST_FUNCTION)
+	    {
+	      gfc_error ("Statement function '%s' is invalid "
+			 "in procedure pointer assignment at %L",
+			 rvalue->symtree->name, &rvalue->where);
+	      return FAILURE;
+	    }
+	  if (attr.proc == PROC_INTERNAL &&
+	      gfc_notify_std (GFC_STD_F2008, "Internal procedure '%s' is "
+			      "invalid in procedure pointer assignment at %L",
+			      rvalue->symtree->name, &rvalue->where) == FAILURE)
+	    return FAILURE;
+	}
+
+      /* Ensure that the calling convention is the same. As other attributes
+	 such as DLLEXPORT may differ, one explicitly only tests for the
+	 calling conventions.  */
+      if (rvalue->expr_type == EXPR_VARIABLE
+	  && lvalue->symtree->n.sym->attr.ext_attr
+	       != rvalue->symtree->n.sym->attr.ext_attr)
+	{
+	  symbol_attribute calls;
+
+	  calls.ext_attr = 0;
+	  gfc_add_ext_attribute (&calls, EXT_ATTR_CDECL, NULL);
+	  gfc_add_ext_attribute (&calls, EXT_ATTR_STDCALL, NULL);
+	  gfc_add_ext_attribute (&calls, EXT_ATTR_FASTCALL, NULL);
+
+	  if ((calls.ext_attr & lvalue->symtree->n.sym->attr.ext_attr)
+	      != (calls.ext_attr & rvalue->symtree->n.sym->attr.ext_attr))
+	    {
+	      gfc_error ("Mismatch in the procedure pointer assignment "
+			 "at %L: mismatch in the calling convention",
+			 &rvalue->where);
+	  return FAILURE;
+	    }
+	}
+
+      if (gfc_is_proc_ptr_comp (lvalue, &comp))
+	s1 = comp->ts.interface;
+      else
+	s1 = lvalue->symtree->n.sym;
+
+      if (gfc_is_proc_ptr_comp (rvalue, &comp))
+	{
+	  s2 = comp->ts.interface;
+	  name = comp->name;
+	}
+      else if (rvalue->expr_type == EXPR_FUNCTION)
+	{
+	  s2 = rvalue->symtree->n.sym->result;
+	  name = rvalue->symtree->n.sym->result->name;
+	}
+      else
+	{
+	  s2 = rvalue->symtree->n.sym;
+	  name = rvalue->symtree->n.sym->name;
+	}
+
+      if (s1 && s2 && !gfc_compare_interfaces (s1, s2, name, 0, 1,
+					       err, sizeof(err)))
+	{
+	  gfc_error ("Interface mismatch in procedure pointer assignment "
+		     "at %L: %s", &rvalue->where, err);
+	  return FAILURE;
+	}
+
+      return SUCCESS;
+    }
+
+  if (!gfc_compare_types (&lvalue->ts, &rvalue->ts))
+    {
+      gfc_error ("Different types in pointer assignment at %L; attempted "
+		 "assignment of %s to %s", &lvalue->where, 
+		 gfc_typename (&rvalue->ts), gfc_typename (&lvalue->ts));
+      return FAILURE;
+    }
+
+  if (lvalue->ts.type != BT_CLASS && lvalue->ts.kind != rvalue->ts.kind)
+    {
+      gfc_error ("Different kind type parameters in pointer "
+		 "assignment at %L", &lvalue->where);
+      return FAILURE;
+    }
+
+  if (lvalue->rank != rvalue->rank && !rank_remap)
+    {
+      gfc_error ("Different ranks in pointer assignment at %L", &lvalue->where);
+      return FAILURE;
+    }
+
+  if (lvalue->ts.type == BT_CLASS && rvalue->ts.type == BT_DERIVED)
+    /* Make sure the vtab is present.  */
+    gfc_find_derived_vtab (rvalue->ts.u.derived);
+
+  /* Check rank remapping.  */
+  if (rank_remap)
+    {
+      mpz_t lsize, rsize;
+
+      /* If this can be determined, check that the target must be at least as
+	 large as the pointer assigned to it is.  */
+      if (gfc_array_size (lvalue, &lsize) == SUCCESS
+	  && gfc_array_size (rvalue, &rsize) == SUCCESS
+	  && mpz_cmp (rsize, lsize) < 0)
+	{
+	  gfc_error ("Rank remapping target is smaller than size of the"
+		     " pointer (%ld < %ld) at %L",
+		     mpz_get_si (rsize), mpz_get_si (lsize),
+		     &lvalue->where);
+	  return FAILURE;
+	}
+
+      /* The target must be either rank one or it must be simply contiguous
+	 and F2008 must be allowed.  */
+      if (rvalue->rank != 1)
+	{
+	  if (!gfc_is_simply_contiguous (rvalue, true))
+	    {
+	      gfc_error ("Rank remapping target must be rank 1 or"
+			 " simply contiguous at %L", &rvalue->where);
+	      return FAILURE;
+	    }
+	  if (gfc_notify_std (GFC_STD_F2008, "Fortran 2008: Rank remapping"
+			      " target is not rank 1 at %L", &rvalue->where)
+		== FAILURE)
+	    return FAILURE;
+	}
+    }
+
+  /* Now punt if we are dealing with a NULLIFY(X) or X = NULL(X).  */
+  if (rvalue->expr_type == EXPR_NULL)
+    return SUCCESS;
+
+  if (lvalue->ts.type == BT_CHARACTER)
+    {
+      gfc_try t = gfc_check_same_strlen (lvalue, rvalue, "pointer assignment");
+      if (t == FAILURE)
+	return FAILURE;
+    }
+
+  if (rvalue->expr_type == EXPR_VARIABLE && is_subref_array (rvalue))
+    lvalue->symtree->n.sym->attr.subref_array_pointer = 1;
+
+  attr = gfc_expr_attr (rvalue);
+
+  if (rvalue->expr_type == EXPR_FUNCTION && !attr.pointer)
+    {
+      gfc_error ("Target expression in pointer assignment "
+		 "at %L must deliver a pointer result",
+		 &rvalue->where);
+      return FAILURE;
+    }
+
+  if (!attr.target && !attr.pointer)
+    {
+      gfc_error ("Pointer assignment target is neither TARGET "
+		 "nor POINTER at %L", &rvalue->where);
+      return FAILURE;
+    }
+
+  if (is_pure && gfc_impure_variable (rvalue->symtree->n.sym))
+    {
+      gfc_error ("Bad target in pointer assignment in PURE "
+		 "procedure at %L", &rvalue->where);
+    }
+
+  if (is_implicit_pure && gfc_impure_variable (rvalue->symtree->n.sym))
+    gfc_current_ns->proc_name->attr.implicit_pure = 0;
+    
+
+  if (gfc_has_vector_index (rvalue))
+    {
+      gfc_error ("Pointer assignment with vector subscript "
+		 "on rhs at %L", &rvalue->where);
+      return FAILURE;
+    }
+
+  if (attr.is_protected && attr.use_assoc
+      && !(attr.pointer || attr.proc_pointer))
+    {
+      gfc_error ("Pointer assignment target has PROTECTED "
+		 "attribute at %L", &rvalue->where);
+      return FAILURE;
+    }
+
+  /* F2008, C725. For PURE also C1283.  */
+  if (rvalue->expr_type == EXPR_VARIABLE
+      && gfc_is_coindexed (rvalue))
+    {
+      gfc_ref *ref;
+      for (ref = rvalue->ref; ref; ref = ref->next)
+	if (ref->type == REF_ARRAY && ref->u.ar.codimen)
+	  {
+	    gfc_error ("Data target at %L shall not have a coindex",
+		       &rvalue->where);
+	    return FAILURE;
+	  }
+    }
+
+  return SUCCESS;
+}
+
+
+/* Relative of gfc_check_assign() except that the lvalue is a single
+   symbol.  Used for initialization assignments.  */
+
+gfc_try
+gfc_check_assign_symbol (gfc_symbol *sym, gfc_expr *rvalue)
+{
+  gfc_expr lvalue;
+  gfc_try r;
+
+  memset (&lvalue, '\0', sizeof (gfc_expr));
+
+  lvalue.expr_type = EXPR_VARIABLE;
+  lvalue.ts = sym->ts;
+  if (sym->as)
+    lvalue.rank = sym->as->rank;
+  lvalue.symtree = (gfc_symtree *) gfc_getmem (sizeof (gfc_symtree));
+  lvalue.symtree->n.sym = sym;
+  lvalue.where = sym->declared_at;
+
+  if (sym->attr.pointer || sym->attr.proc_pointer
+      || (sym->ts.type == BT_CLASS && CLASS_DATA (sym)->attr.class_pointer
+	  && rvalue->expr_type == EXPR_NULL))
+    r = gfc_check_pointer_assign (&lvalue, rvalue);
+  else
+    r = gfc_check_assign (&lvalue, rvalue, 1);
+
+  gfc_free (lvalue.symtree);
+
+  if (r == FAILURE)
+    return r;
+  
+  if (sym->attr.pointer && rvalue->expr_type != EXPR_NULL)
+    {
+      /* F08:C461. Additional checks for pointer initialization.  */
+      symbol_attribute attr;
+      attr = gfc_expr_attr (rvalue);
+      if (attr.allocatable)
+	{
+	  gfc_error ("Pointer initialization target at %C "
+	             "must not be ALLOCATABLE ");
+	  return FAILURE;
+	}
+      if (!attr.target || attr.pointer)
+	{
+	  gfc_error ("Pointer initialization target at %C "
+		     "must have the TARGET attribute");
+	  return FAILURE;
+	}
+      if (!attr.save)
+	{
+	  gfc_error ("Pointer initialization target at %C "
+		     "must have the SAVE attribute");
+	  return FAILURE;
+	}
+    }
+    
+  if (sym->attr.proc_pointer && rvalue->expr_type != EXPR_NULL)
+    {
+      /* F08:C1220. Additional checks for procedure pointer initialization.  */
+      symbol_attribute attr = gfc_expr_attr (rvalue);
+      if (attr.proc_pointer)
+	{
+	  gfc_error ("Procedure pointer initialization target at %L "
+		     "may not be a procedure pointer", &rvalue->where);
+	  return FAILURE;
+	}
+    }
+
+  return SUCCESS;
+}
+
+
+/* Check for default initializer; sym->value is not enough
+   as it is also set for EXPR_NULL of allocatables.  */
+
+bool
+gfc_has_default_initializer (gfc_symbol *der)
+{
+  gfc_component *c;
+
+  gcc_assert (der->attr.flavor == FL_DERIVED);
+  for (c = der->components; c; c = c->next)
+    if (c->ts.type == BT_DERIVED)
+      {
+        if (!c->attr.pointer
+	     && gfc_has_default_initializer (c->ts.u.derived))
+	  return true;
+	if (c->attr.pointer && c->initializer)
+	  return true;
+      }
+    else
+      {
+        if (c->initializer)
+	  return true;
+      }
+
+  return false;
+}
+
+
+/* Get an expression for a default initializer.  */
+
+gfc_expr *
+gfc_default_initializer (gfc_typespec *ts)
+{
+  gfc_expr *init;
+  gfc_component *comp;
+
+  /* See if we have a default initializer in this, but not in nested
+     types (otherwise we could use gfc_has_default_initializer()).  */
+  for (comp = ts->u.derived->components; comp; comp = comp->next)
+    if (comp->initializer || comp->attr.allocatable
+	|| (comp->ts.type == BT_CLASS && CLASS_DATA (comp)
+	    && CLASS_DATA (comp)->attr.allocatable))
+      break;
+
+  if (!comp)
+    return NULL;
+
+  init = gfc_get_structure_constructor_expr (ts->type, ts->kind,
+					     &ts->u.derived->declared_at);
+  init->ts = *ts;
+
+  for (comp = ts->u.derived->components; comp; comp = comp->next)
+    {
+      gfc_constructor *ctor = gfc_constructor_get();
+
+      if (comp->initializer)
+	ctor->expr = gfc_copy_expr (comp->initializer);
+
+      if (comp->attr.allocatable
+	  || (comp->ts.type == BT_CLASS && CLASS_DATA (comp)->attr.allocatable))
+	{
+	  ctor->expr = gfc_get_expr ();
+	  ctor->expr->expr_type = EXPR_NULL;
+	  ctor->expr->ts = comp->ts;
+	}
+
+      gfc_constructor_append (&init->value.constructor, ctor);
+    }
+
+  return init;
+}
+
+
+/* Given a symbol, create an expression node with that symbol as a
+   variable. If the symbol is array valued, setup a reference of the
+   whole array.  */
+
+gfc_expr *
+gfc_get_variable_expr (gfc_symtree *var)
+{
+  gfc_expr *e;
+
+  e = gfc_get_expr ();
+  e->expr_type = EXPR_VARIABLE;
+  e->symtree = var;
+  e->ts = var->n.sym->ts;
+
+  if (var->n.sym->as != NULL)
+    {
+      e->rank = var->n.sym->as->rank;
+      e->ref = gfc_get_ref ();
+      e->ref->type = REF_ARRAY;
+      e->ref->u.ar.type = AR_FULL;
+    }
+
+  return e;
+}
+
+
+gfc_expr *
+gfc_lval_expr_from_sym (gfc_symbol *sym)
+{
+  gfc_expr *lval;
+  lval = gfc_get_expr ();
+  lval->expr_type = EXPR_VARIABLE;
+  lval->where = sym->declared_at;
+  lval->ts = sym->ts;
+  lval->symtree = gfc_find_symtree (sym->ns->sym_root, sym->name);
+
+  /* It will always be a full array.  */
+  lval->rank = sym->as ? sym->as->rank : 0;
+  if (lval->rank)
+    {
+      lval->ref = gfc_get_ref ();
+      lval->ref->type = REF_ARRAY;
+      lval->ref->u.ar.type = AR_FULL;
+      lval->ref->u.ar.dimen = lval->rank;
+      lval->ref->u.ar.where = sym->declared_at;
+      lval->ref->u.ar.as = sym->as;
+    }
+
+  return lval;
+}
+
+
+/* Returns the array_spec of a full array expression.  A NULL is
+   returned otherwise.  */
+gfc_array_spec *
+gfc_get_full_arrayspec_from_expr (gfc_expr *expr)
+{
+  gfc_array_spec *as;
+  gfc_ref *ref;
+
+  if (expr->rank == 0)
+    return NULL;
+
+  /* Follow any component references.  */
+  if (expr->expr_type == EXPR_VARIABLE
+      || expr->expr_type == EXPR_CONSTANT)
+    {
+      as = expr->symtree->n.sym->as;
+      for (ref = expr->ref; ref; ref = ref->next)
+	{
+	  switch (ref->type)
+	    {
+	    case REF_COMPONENT:
+	      as = ref->u.c.component->as;
+	      continue;
+
+	    case REF_SUBSTRING:
+	      continue;
+
+	    case REF_ARRAY:
+	      {
+		switch (ref->u.ar.type)
+		  {
+		  case AR_ELEMENT:
+		  case AR_SECTION:
+		  case AR_UNKNOWN:
+		    as = NULL;
+		    continue;
+
+		  case AR_FULL:
+		    break;
+		  }
+		break;
+	      }
+	    }
+	}
+    }
+  else
+    as = NULL;
+
+  return as;
+}
+
+
+/* General expression traversal function.  */
+
+bool
+gfc_traverse_expr (gfc_expr *expr, gfc_symbol *sym,
+		   bool (*func)(gfc_expr *, gfc_symbol *, int*),
+		   int f)
+{
+  gfc_array_ref ar;
+  gfc_ref *ref;
+  gfc_actual_arglist *args;
+  gfc_constructor *c;
+  int i;
+
+  if (!expr)
+    return false;
+
+  if ((*func) (expr, sym, &f))
+    return true;
+
+  if (expr->ts.type == BT_CHARACTER
+	&& expr->ts.u.cl
+	&& expr->ts.u.cl->length
+	&& expr->ts.u.cl->length->expr_type != EXPR_CONSTANT
+	&& gfc_traverse_expr (expr->ts.u.cl->length, sym, func, f))
+    return true;
+
+  switch (expr->expr_type)
+    {
+    case EXPR_PPC:
+    case EXPR_COMPCALL:
+    case EXPR_FUNCTION:
+      for (args = expr->value.function.actual; args; args = args->next)
+	{
+	  if (gfc_traverse_expr (args->expr, sym, func, f))
+	    return true;
+	}
+      break;
+
+    case EXPR_VARIABLE:
+    case EXPR_CONSTANT:
+    case EXPR_NULL:
+    case EXPR_SUBSTRING:
+      break;
+
+    case EXPR_STRUCTURE:
+    case EXPR_ARRAY:
+      for (c = gfc_constructor_first (expr->value.constructor);
+	   c; c = gfc_constructor_next (c))
+	{
+	  if (gfc_traverse_expr (c->expr, sym, func, f))
+	    return true;
+	  if (c->iterator)
+	    {
+	      if (gfc_traverse_expr (c->iterator->var, sym, func, f))
+		return true;
+	      if (gfc_traverse_expr (c->iterator->start, sym, func, f))
+		return true;
+	      if (gfc_traverse_expr (c->iterator->end, sym, func, f))
+		return true;
+	      if (gfc_traverse_expr (c->iterator->step, sym, func, f))
+		return true;
+	    }
+	}
+      break;
+
+    case EXPR_OP:
+      if (gfc_traverse_expr (expr->value.op.op1, sym, func, f))
+	return true;
+      if (gfc_traverse_expr (expr->value.op.op2, sym, func, f))
+	return true;
+      break;
+
+    default:
+      gcc_unreachable ();
+      break;
+    }
+
+  ref = expr->ref;
+  while (ref != NULL)
+    {
+      switch (ref->type)
+	{
+	case  REF_ARRAY:
+	  ar = ref->u.ar;
+	  for (i = 0; i < GFC_MAX_DIMENSIONS; i++)
+	    {
+	      if (gfc_traverse_expr (ar.start[i], sym, func, f))
+		return true;
+	      if (gfc_traverse_expr (ar.end[i], sym, func, f))
+		return true;
+	      if (gfc_traverse_expr (ar.stride[i], sym, func, f))
+		return true;
+	    }
+	  break;
+
+	case REF_SUBSTRING:
+	  if (gfc_traverse_expr (ref->u.ss.start, sym, func, f))
+	    return true;
+	  if (gfc_traverse_expr (ref->u.ss.end, sym, func, f))
+	    return true;
+	  break;
+
+	case REF_COMPONENT:
+	  if (ref->u.c.component->ts.type == BT_CHARACTER
+		&& ref->u.c.component->ts.u.cl
+		&& ref->u.c.component->ts.u.cl->length
+		&& ref->u.c.component->ts.u.cl->length->expr_type
+		     != EXPR_CONSTANT
+		&& gfc_traverse_expr (ref->u.c.component->ts.u.cl->length,
+				      sym, func, f))
+	    return true;
+
+	  if (ref->u.c.component->as)
+	    for (i = 0; i < ref->u.c.component->as->rank
+			    + ref->u.c.component->as->corank; i++)
+	      {
+		if (gfc_traverse_expr (ref->u.c.component->as->lower[i],
+				       sym, func, f))
+		  return true;
+		if (gfc_traverse_expr (ref->u.c.component->as->upper[i],
+				       sym, func, f))
+		  return true;
+	      }
+	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+      ref = ref->next;
+    }
+  return false;
+}
+
+/* Traverse expr, marking all EXPR_VARIABLE symbols referenced.  */
+
+static bool
+expr_set_symbols_referenced (gfc_expr *expr,
+			     gfc_symbol *sym ATTRIBUTE_UNUSED,
+			     int *f ATTRIBUTE_UNUSED)
+{
+  if (expr->expr_type != EXPR_VARIABLE)
+    return false;
+  gfc_set_sym_referenced (expr->symtree->n.sym);
+  return false;
+}
+
+void
+gfc_expr_set_symbols_referenced (gfc_expr *expr)
+{
+  gfc_traverse_expr (expr, NULL, expr_set_symbols_referenced, 0);
+}
+
+
+/* Determine if an expression is a procedure pointer component. If yes, the
+   argument 'comp' will point to the component (provided that 'comp' was
+   provided).  */
+
+bool
+gfc_is_proc_ptr_comp (gfc_expr *expr, gfc_component **comp)
+{
+  gfc_ref *ref;
+  bool ppc = false;
+
+  if (!expr || !expr->ref)
+    return false;
+
+  ref = expr->ref;
+  while (ref->next)
+    ref = ref->next;
+
+  if (ref->type == REF_COMPONENT)
+    {
+      ppc = ref->u.c.component->attr.proc_pointer;
+      if (ppc && comp)
+	*comp = ref->u.c.component;
+    }
+
+  return ppc;
+}
+
+
+/* Walk an expression tree and check each variable encountered for being typed.
+   If strict is not set, a top-level variable is tolerated untyped in -std=gnu
+   mode as is a basic arithmetic expression using those; this is for things in
+   legacy-code like:
+
+     INTEGER :: arr(n), n
+     INTEGER :: arr(n + 1), n
+
+   The namespace is needed for IMPLICIT typing.  */
+
+static gfc_namespace* check_typed_ns;
+
+static bool
+expr_check_typed_help (gfc_expr* e, gfc_symbol* sym ATTRIBUTE_UNUSED,
+                       int* f ATTRIBUTE_UNUSED)
+{
+  gfc_try t;
+
+  if (e->expr_type != EXPR_VARIABLE)
+    return false;
+
+  gcc_assert (e->symtree);
+  t = gfc_check_symbol_typed (e->symtree->n.sym, check_typed_ns,
+                              true, e->where);
+
+  return (t == FAILURE);
+}
+
+gfc_try
+gfc_expr_check_typed (gfc_expr* e, gfc_namespace* ns, bool strict)
+{
+  bool error_found;
+
+  /* If this is a top-level variable or EXPR_OP, do the check with strict given
+     to us.  */
+  if (!strict)
+    {
+      if (e->expr_type == EXPR_VARIABLE && !e->ref)
+	return gfc_check_symbol_typed (e->symtree->n.sym, ns, strict, e->where);
+
+      if (e->expr_type == EXPR_OP)
+	{
+	  gfc_try t = SUCCESS;
+
+	  gcc_assert (e->value.op.op1);
+	  t = gfc_expr_check_typed (e->value.op.op1, ns, strict);
+
+	  if (t == SUCCESS && e->value.op.op2)
+	    t = gfc_expr_check_typed (e->value.op.op2, ns, strict);
+
+	  return t;
+	}
+    }
+
+  /* Otherwise, walk the expression and do it strictly.  */
+  check_typed_ns = ns;
+  error_found = gfc_traverse_expr (e, NULL, &expr_check_typed_help, 0);
+
+  return error_found ? FAILURE : SUCCESS;
+}
+
+
+/* Walk an expression tree and replace all dummy symbols by the corresponding
+   symbol in the formal_ns of "sym". Needed for copying interfaces in PROCEDURE
+   statements. The boolean return value is required by gfc_traverse_expr.  */
+
+static bool
+replace_symbol (gfc_expr *expr, gfc_symbol *sym, int *i ATTRIBUTE_UNUSED)
+{
+  if ((expr->expr_type == EXPR_VARIABLE 
+       || (expr->expr_type == EXPR_FUNCTION
+	   && !gfc_is_intrinsic (expr->symtree->n.sym, 0, expr->where)))
+      && expr->symtree->n.sym->ns == sym->ts.interface->formal_ns
+      && expr->symtree->n.sym->attr.dummy)
+    {
+      gfc_symtree *root = sym->formal_ns ? sym->formal_ns->sym_root
+					 : gfc_current_ns->sym_root;
+      gfc_symtree *stree = gfc_find_symtree (root, expr->symtree->n.sym->name);
+      gcc_assert (stree);
+      stree->n.sym->attr = expr->symtree->n.sym->attr;
+      expr->symtree = stree;
+    }
+  return false;
+}
+
+void
+gfc_expr_replace_symbols (gfc_expr *expr, gfc_symbol *dest)
+{
+  gfc_traverse_expr (expr, dest, &replace_symbol, 0);
+}
+
+
+/* The following is analogous to 'replace_symbol', and needed for copying
+   interfaces for procedure pointer components. The argument 'sym' must formally
+   be a gfc_symbol, so that the function can be passed to gfc_traverse_expr.
+   However, it gets actually passed a gfc_component (i.e. the procedure pointer
+   component in whose formal_ns the arguments have to be).  */
+
+static bool
+replace_comp (gfc_expr *expr, gfc_symbol *sym, int *i ATTRIBUTE_UNUSED)
+{
+  gfc_component *comp;
+  comp = (gfc_component *)sym;
+  if ((expr->expr_type == EXPR_VARIABLE 
+       || (expr->expr_type == EXPR_FUNCTION
+	   && !gfc_is_intrinsic (expr->symtree->n.sym, 0, expr->where)))
+      && expr->symtree->n.sym->ns == comp->ts.interface->formal_ns)
+    {
+      gfc_symtree *stree;
+      gfc_namespace *ns = comp->formal_ns;
+      /* Don't use gfc_get_symtree as we prefer to fail badly if we don't find
+	 the symtree rather than create a new one (and probably fail later).  */
+      stree = gfc_find_symtree (ns ? ns->sym_root : gfc_current_ns->sym_root,
+		      		expr->symtree->n.sym->name);
+      gcc_assert (stree);
+      stree->n.sym->attr = expr->symtree->n.sym->attr;
+      expr->symtree = stree;
+    }
+  return false;
+}
+
+void
+gfc_expr_replace_comp (gfc_expr *expr, gfc_component *dest)
+{
+  gfc_traverse_expr (expr, (gfc_symbol *)dest, &replace_comp, 0);
+}
+
+
+bool
+gfc_is_coindexed (gfc_expr *e)
+{
+  gfc_ref *ref;
+
+  for (ref = e->ref; ref; ref = ref->next)
+    if (ref->type == REF_ARRAY && ref->u.ar.codimen > 0)
+      return true;
+
+  return false;
+}
+
+
+int
+gfc_get_corank (gfc_expr *e)
+{
+  int corank;
+  gfc_ref *ref;
+  corank = e->symtree->n.sym->as ? e->symtree->n.sym->as->corank : 0;
+  for (ref = e->ref; ref; ref = ref->next)
+    {
+      if (ref->type == REF_ARRAY)
+	corank = ref->u.ar.as->corank;
+      gcc_assert (ref->type != REF_SUBSTRING);
+    }
+  return corank;
+}
+
+
+/* Check whether the expression has an ultimate allocatable component.
+   Being itself allocatable does not count.  */
+bool
+gfc_has_ultimate_allocatable (gfc_expr *e)
+{
+  gfc_ref *ref, *last = NULL;
+
+  if (e->expr_type != EXPR_VARIABLE)
+    return false;
+
+  for (ref = e->ref; ref; ref = ref->next)
+    if (ref->type == REF_COMPONENT)
+      last = ref;
+
+  if (last && last->u.c.component->ts.type == BT_CLASS)
+    return CLASS_DATA (last->u.c.component)->attr.alloc_comp;
+  else if (last && last->u.c.component->ts.type == BT_DERIVED)
+    return last->u.c.component->ts.u.derived->attr.alloc_comp;
+  else if (last)
+    return false;
+
+  if (e->ts.type == BT_CLASS)
+    return CLASS_DATA (e)->attr.alloc_comp;
+  else if (e->ts.type == BT_DERIVED)
+    return e->ts.u.derived->attr.alloc_comp;
+  else
+    return false;
+}
+
+
+/* Check whether the expression has an pointer component.
+   Being itself a pointer does not count.  */
+bool
+gfc_has_ultimate_pointer (gfc_expr *e)
+{
+  gfc_ref *ref, *last = NULL;
+
+  if (e->expr_type != EXPR_VARIABLE)
+    return false;
+
+  for (ref = e->ref; ref; ref = ref->next)
+    if (ref->type == REF_COMPONENT)
+      last = ref;
+ 
+  if (last && last->u.c.component->ts.type == BT_CLASS)
+    return CLASS_DATA (last->u.c.component)->attr.pointer_comp;
+  else if (last && last->u.c.component->ts.type == BT_DERIVED)
+    return last->u.c.component->ts.u.derived->attr.pointer_comp;
+  else if (last)
+    return false;
+
+  if (e->ts.type == BT_CLASS)
+    return CLASS_DATA (e)->attr.pointer_comp;
+  else if (e->ts.type == BT_DERIVED)
+    return e->ts.u.derived->attr.pointer_comp;
+  else
+    return false;
+}
+
+
+/* Check whether an expression is "simply contiguous", cf. F2008, 6.5.4.
+   Note: A scalar is not regarded as "simply contiguous" by the standard.
+   if bool is not strict, some futher checks are done - for instance,
+   a "(::1)" is accepted.  */
+
+bool
+gfc_is_simply_contiguous (gfc_expr *expr, bool strict)
+{
+  bool colon;
+  int i;
+  gfc_array_ref *ar = NULL;
+  gfc_ref *ref, *part_ref = NULL;
+
+  if (expr->expr_type == EXPR_FUNCTION)
+    return expr->value.function.esym
+	   ? expr->value.function.esym->result->attr.contiguous : false;
+  else if (expr->expr_type != EXPR_VARIABLE)
+    return false;
+
+  if (expr->rank == 0)
+    return false;
+
+  for (ref = expr->ref; ref; ref = ref->next)
+    {
+      if (ar)
+	return false; /* Array shall be last part-ref. */
+
+      if (ref->type == REF_COMPONENT)
+	part_ref  = ref;
+      else if (ref->type == REF_SUBSTRING)
+	return false;
+      else if (ref->u.ar.type != AR_ELEMENT)
+	ar = &ref->u.ar;
+    }
+
+  if ((part_ref && !part_ref->u.c.component->attr.contiguous
+       && part_ref->u.c.component->attr.pointer)
+      || (!part_ref && !expr->symtree->n.sym->attr.contiguous
+	  && (expr->symtree->n.sym->attr.pointer
+	      || expr->symtree->n.sym->as->type == AS_ASSUMED_SHAPE)))
+    return false;
+
+  if (!ar || ar->type == AR_FULL)
+    return true;
+
+  gcc_assert (ar->type == AR_SECTION);
+
+  /* Check for simply contiguous array */
+  colon = true;
+  for (i = 0; i < ar->dimen; i++)
+    {
+      if (ar->dimen_type[i] == DIMEN_VECTOR)
+	return false;
+
+      if (ar->dimen_type[i] == DIMEN_ELEMENT)
+	{
+	  colon = false;
+	  continue;
+	}
+
+      gcc_assert (ar->dimen_type[i] == DIMEN_RANGE);
+
+
+      /* If the previous section was not contiguous, that's an error,
+	 unless we have effective only one element and checking is not
+	 strict.  */
+      if (!colon && (strict || !ar->start[i] || !ar->end[i]
+		     || ar->start[i]->expr_type != EXPR_CONSTANT
+		     || ar->end[i]->expr_type != EXPR_CONSTANT
+		     || mpz_cmp (ar->start[i]->value.integer,
+				 ar->end[i]->value.integer) != 0))
+	return false;
+
+      /* Following the standard, "(::1)" or - if known at compile time -
+	 "(lbound:ubound)" are not simply contigous; if strict
+	 is false, they are regarded as simply contiguous.  */
+      if (ar->stride[i] && (strict || ar->stride[i]->expr_type != EXPR_CONSTANT
+			    || ar->stride[i]->ts.type != BT_INTEGER
+			    || mpz_cmp_si (ar->stride[i]->value.integer, 1) != 0))
+	return false;
+
+      if (ar->start[i]
+	  && (strict || ar->start[i]->expr_type != EXPR_CONSTANT
+	      || !ar->as->lower[i]
+	      || ar->as->lower[i]->expr_type != EXPR_CONSTANT
+	      || mpz_cmp (ar->start[i]->value.integer,
+			  ar->as->lower[i]->value.integer) != 0))
+	colon = false;
+
+      if (ar->end[i]
+	  && (strict || ar->end[i]->expr_type != EXPR_CONSTANT
+	      || !ar->as->upper[i]
+	      || ar->as->upper[i]->expr_type != EXPR_CONSTANT
+	      || mpz_cmp (ar->end[i]->value.integer,
+			  ar->as->upper[i]->value.integer) != 0))
+	colon = false;
+    }
+  
+  return true;
+}
+
+
+/* Build call to an intrinsic procedure.  The number of arguments has to be
+   passed (rather than ending the list with a NULL value) because we may
+   want to add arguments but with a NULL-expression.  */
+
+gfc_expr*
+gfc_build_intrinsic_call (gfc_namespace *ns, gfc_isym_id id, const char* name,
+			  locus where, unsigned numarg, ...)
+{
+  gfc_expr* result;
+  gfc_actual_arglist* atail;
+  gfc_intrinsic_sym* isym;
+  va_list ap;
+  unsigned i;
+  const char *mangled_name = gfc_get_string (GFC_PREFIX ("%s"), name);
+
+  isym = gfc_intrinsic_function_by_id (id);
+  gcc_assert (isym);
+  
+  result = gfc_get_expr ();
+  result->expr_type = EXPR_FUNCTION;
+  result->ts = isym->ts;
+  result->where = where;
+  result->value.function.name = mangled_name;
+  result->value.function.isym = isym;
+
+  gfc_get_sym_tree (mangled_name, ns, &result->symtree, false);
+  gfc_commit_symbol (result->symtree->n.sym);
+  gcc_assert (result->symtree
+	      && (result->symtree->n.sym->attr.flavor == FL_PROCEDURE
+		  || result->symtree->n.sym->attr.flavor == FL_UNKNOWN));
+
+  result->symtree->n.sym->intmod_sym_id = id;
+  result->symtree->n.sym->attr.flavor = FL_PROCEDURE;
+  result->symtree->n.sym->attr.intrinsic = 1;
+
+  va_start (ap, numarg);
+  atail = NULL;
+  for (i = 0; i < numarg; ++i)
+    {
+      if (atail)
+	{
+	  atail->next = gfc_get_actual_arglist ();
+	  atail = atail->next;
+	}
+      else
+	atail = result->value.function.actual = gfc_get_actual_arglist ();
+
+      atail->expr = va_arg (ap, gfc_expr*);
+    }
+  va_end (ap);
+
+  return result;
+}
+
+
+/* Check if an expression may appear in a variable definition context
+   (F2008, 16.6.7) or pointer association context (F2008, 16.6.8).
+   This is called from the various places when resolving
+   the pieces that make up such a context.
+
+   Optionally, a possible error message can be suppressed if context is NULL
+   and just the return status (SUCCESS / FAILURE) be requested.  */
+
+gfc_try
+gfc_check_vardef_context (gfc_expr* e, bool pointer, const char* context)
+{
+  gfc_symbol* sym = NULL;
+  bool is_pointer;
+  bool check_intentin;
+  bool ptr_component;
+  symbol_attribute attr;
+  gfc_ref* ref;
+
+  if (e->expr_type == EXPR_VARIABLE)
+    {
+      gcc_assert (e->symtree);
+      sym = e->symtree->n.sym;
+    }
+  else if (e->expr_type == EXPR_FUNCTION)
+    {
+      gcc_assert (e->symtree);
+      sym = e->value.function.esym ? e->value.function.esym : e->symtree->n.sym;
+    }
+
+  attr = gfc_expr_attr (e);
+  if (!pointer && e->expr_type == EXPR_FUNCTION && attr.pointer)
+    {
+      if (!(gfc_option.allow_std & GFC_STD_F2008))
+	{
+	  if (context)
+	    gfc_error ("Fortran 2008: Pointer functions in variable definition"
+		       " context (%s) at %L", context, &e->where);
+	  return FAILURE;
+	}
+    }
+  else if (e->expr_type != EXPR_VARIABLE)
+    {
+      if (context)
+	gfc_error ("Non-variable expression in variable definition context (%s)"
+		   " at %L", context, &e->where);
+      return FAILURE;
+    }
+
+  if (!pointer && sym->attr.flavor == FL_PARAMETER)
+    {
+      if (context)
+	gfc_error ("Named constant '%s' in variable definition context (%s)"
+		   " at %L", sym->name, context, &e->where);
+      return FAILURE;
+    }
+  if (!pointer && sym->attr.flavor != FL_VARIABLE
+      && !(sym->attr.flavor == FL_PROCEDURE && sym == sym->result)
+      && !(sym->attr.flavor == FL_PROCEDURE && sym->attr.proc_pointer))
+    {
+      if (context)
+	gfc_error ("'%s' in variable definition context (%s) at %L is not"
+		   " a variable", sym->name, context, &e->where);
+      return FAILURE;
+    }
+
+  /* Find out whether the expr is a pointer; this also means following
+     component references to the last one.  */
+  is_pointer = (attr.pointer || attr.proc_pointer);
+  if (pointer && !is_pointer)
+    {
+      if (context)
+	gfc_error ("Non-POINTER in pointer association context (%s)"
+		   " at %L", context, &e->where);
+      return FAILURE;
+    }
+
+  /* INTENT(IN) dummy argument.  Check this, unless the object itself is
+     the component of sub-component of a pointer.  Obviously,
+     procedure pointers are of no interest here.  */
+  check_intentin = true;
+  ptr_component = sym->attr.pointer;
+  for (ref = e->ref; ref && check_intentin; ref = ref->next)
+    {
+      if (ptr_component && ref->type == REF_COMPONENT)
+	check_intentin = false;
+      if (ref->type == REF_COMPONENT && ref->u.c.component->attr.pointer)
+	{
+	  ptr_component = true;
+	  if (!pointer)
+	    check_intentin = false;
+	}
+    }
+  if (check_intentin && sym->attr.intent == INTENT_IN)
+    {
+      if (pointer && is_pointer)
+	{
+	  if (context)
+	    gfc_error ("Dummy argument '%s' with INTENT(IN) in pointer"
+		       " association context (%s) at %L",
+		       sym->name, context, &e->where);
+	  return FAILURE;
+	}
+      if (!pointer && !is_pointer && !sym->attr.pointer)
+	{
+	  if (context)
+	    gfc_error ("Dummy argument '%s' with INTENT(IN) in variable"
+		       " definition context (%s) at %L",
+		       sym->name, context, &e->where);
+	  return FAILURE;
+	}
+    }
+
+  /* PROTECTED and use-associated.  */
+  if (sym->attr.is_protected && sym->attr.use_assoc  && check_intentin)
+    {
+      if (pointer && is_pointer)
+	{
+	  if (context)
+	    gfc_error ("Variable '%s' is PROTECTED and can not appear in a"
+		       " pointer association context (%s) at %L",
+		       sym->name, context, &e->where);
+	  return FAILURE;
+	}
+      if (!pointer && !is_pointer)
+	{
+	  if (context)
+	    gfc_error ("Variable '%s' is PROTECTED and can not appear in a"
+		       " variable definition context (%s) at %L",
+		       sym->name, context, &e->where);
+	  return FAILURE;
+	}
+    }
+
+  /* Variable not assignable from a PURE procedure but appears in
+     variable definition context.  */
+  if (!pointer && gfc_pure (NULL) && gfc_impure_variable (sym))
+    {
+      if (context)
+	gfc_error ("Variable '%s' can not appear in a variable definition"
+		   " context (%s) at %L in PURE procedure",
+		   sym->name, context, &e->where);
+      return FAILURE;
+    }
+
+  if (!pointer && context && gfc_implicit_pure (NULL)
+      && gfc_impure_variable (sym))
+    {
+      gfc_namespace *ns;
+      gfc_symbol *sym;
+
+      for (ns = gfc_current_ns; ns; ns = ns->parent)
+	{
+	  sym = ns->proc_name;
+	  if (sym == NULL)
+	    break;
+	  if (sym->attr.flavor == FL_PROCEDURE)
+	    {
+	      sym->attr.implicit_pure = 0;
+	      break;
+	    }
+	}
+    }
+  /* Check variable definition context for associate-names.  */
+  if (!pointer && sym->assoc)
+    {
+      const char* name;
+      gfc_association_list* assoc;
+
+      gcc_assert (sym->assoc->target);
+
+      /* If this is a SELECT TYPE temporary (the association is used internally
+	 for SELECT TYPE), silently go over to the target.  */
+      if (sym->attr.select_type_temporary)
+	{
+	  gfc_expr* t = sym->assoc->target;
+
+	  gcc_assert (t->expr_type == EXPR_VARIABLE);
+	  name = t->symtree->name;
+
+	  if (t->symtree->n.sym->assoc)
+	    assoc = t->symtree->n.sym->assoc;
+	  else
+	    assoc = sym->assoc;
+	}
+      else
+	{
+	  name = sym->name;
+	  assoc = sym->assoc;
+	}
+      gcc_assert (name && assoc);
+
+      /* Is association to a valid variable?  */
+      if (!assoc->variable)
+	{
+	  if (context)
+	    {
+	      if (assoc->target->expr_type == EXPR_VARIABLE)
+		gfc_error ("'%s' at %L associated to vector-indexed target can"
+			   " not be used in a variable definition context (%s)",
+			   name, &e->where, context);
+	      else
+		gfc_error ("'%s' at %L associated to expression can"
+			   " not be used in a variable definition context (%s)",
+			   name, &e->where, context);
+	    }
+	  return FAILURE;
+	}
+
+      /* Target must be allowed to appear in a variable definition context.  */
+      if (gfc_check_vardef_context (assoc->target, pointer, NULL) == FAILURE)
+	{
+	  if (context)
+	    gfc_error ("Associate-name '%s' can not appear in a variable"
+		       " definition context (%s) at %L because its target"
+		       " at %L can not, either",
+		       name, context, &e->where,
+		       &assoc->target->where);
+	  return FAILURE;
+	}
+    }
+
+  return SUCCESS;
+}