re PR fortran/25018 (Segfault with simple expression)

2005-12-18  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/25018
	*expr.c(check_inquiry): Return FAILURE if there is no symtree to
	provide a name. Error/warning for assumed character length argument
	to LEN for an initialization expression, using GFC_GNU_STD. Add an
	argument to flag that the expression is not restricted.
	(check_init_expr): Improve the message for a failing variable.
	(gfc_match_init_expr): Call check_enquiry again to make sure that
	unsimplified expressions are not causing unnecessary errors.

2005-12-18  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/25018
	*gfortran.dg/initialization_1.f90: New test.
	*gfortran.dg/enum_5.f90: Change dg-error to new message.
	*gfortran.dg/g77/980616-0.f: The same.

From-SVN: r108753

2 files changed, 37 insertions, 6 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 98e624a..8dbcc23 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,14 @@
+2005-12-18  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/25018
+	*expr.c(check_inquiry): Return FAILURE if there is no symtree to
+	provide a name. Error/warning for assumed character length argument
+	to LEN for an initialization expression, using GFC_GNU_STD. Add an
+	argument to flag that the expression is not restricted.
+	(check_init_expr): Improve the message for a failing variable.
+	(gfc_match_init_expr): Call check_enquiry again to make sure that
+	unsimplified expressions are not causing unnecessary errors.
+
 2005-12-17  Steven G. Kargl  <kargls@comcast.net>
 	    Tobias Schlueter <tobias.schlueter@physik.uni-muenchen.de>
 
diff --git a/gcc/fortran/expr.c b/gcc/fortran/expr.c
index 1ceec01..c1451e3 100644
--- a/gcc/fortran/expr.c
+++ b/gcc/fortran/expr.c
@@ -1365,7 +1365,7 @@ not_numeric:
    this problem here.  */
 
 static try
-check_inquiry (gfc_expr * e)
+check_inquiry (gfc_expr * e, int not_restricted)
 {
   const char *name;
 
@@ -1379,6 +1379,10 @@ check_inquiry (gfc_expr * e)
 
   int i;
 
+  /* An undeclared parameter will get us here (PR25018).  */
+  if (e->symtree == NULL)
+    return FAILURE;
+
   name = e->symtree->n.sym->name;
 
   for (i = 0; inquiry_function[i]; i++)
@@ -1407,6 +1411,15 @@ check_inquiry (gfc_expr * e)
       e->ts = e->symtree->n.sym->ts;
     }
 
+  /* Assumed character length will not reduce to a constant expression
+     with LEN, as required by the standard.  */
+  if (i == 4 && not_restricted
+	&& e->symtree->n.sym->ts.type == BT_CHARACTER
+	&& e->symtree->n.sym->ts.cl->length == NULL)
+    gfc_notify_std (GFC_STD_GNU, "assumed character length "
+		    "variable '%s' in constant expression at %L",
+		    e->symtree->n.sym->name, &e->where);
+
   return SUCCESS;
 }
 
@@ -1440,7 +1453,7 @@ check_init_expr (gfc_expr * e)
     case EXPR_FUNCTION:
       t = SUCCESS;
 
-      if (check_inquiry (e) != SUCCESS)
+      if (check_inquiry (e, 1) != SUCCESS)
 	{
 	  t = SUCCESS;
 	  for (ap = e->value.function.actual; ap; ap = ap->next)
@@ -1478,7 +1491,8 @@ check_init_expr (gfc_expr * e)
 	  break;
 	}
 
-      gfc_error ("Variable '%s' at %L cannot appear in an initialization "
+      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);
       t = FAILURE;
       break;
@@ -1557,8 +1571,14 @@ gfc_match_init_expr (gfc_expr ** result)
       return MATCH_ERROR;
     }
 
-  if (!gfc_is_constant_expr (expr))
-    gfc_internal_error ("Initialization expression didn't reduce %C");
+  /* Not all inquiry functions are simplified to constant expressions
+     so it is necessary to call check_inquiry again.  */ 
+  if (!gfc_is_constant_expr (expr)
+	&& check_inquiry (expr, 1) == FAILURE)
+    {
+      gfc_error ("Initialization expression didn't reduce %C");
+      return MATCH_ERROR;
+    }
 
   *result = expr;
 
@@ -1637,7 +1657,7 @@ static try
 restricted_intrinsic (gfc_expr * e)
 {
   /* TODO: Check constraints on inquiry functions.  7.1.6.2 (7).  */
-  if (check_inquiry (e) == SUCCESS)
+  if (check_inquiry (e, 0) == SUCCESS)
     return SUCCESS;
 
   return restricted_args (e->value.function.actual);